Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Analgesic and antibiotic prescribing decisions of British Columbian dentists and endodontists Buttar, Rene 2014

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
24-ubc_2015_february_buttar_rene.pdf [ 3.74MB ]
Metadata
JSON: 24-1.0167056.json
JSON-LD: 24-1.0167056-ld.json
RDF/XML (Pretty): 24-1.0167056-rdf.xml
RDF/JSON: 24-1.0167056-rdf.json
Turtle: 24-1.0167056-turtle.txt
N-Triples: 24-1.0167056-rdf-ntriples.txt
Original Record: 24-1.0167056-source.json
Full Text
24-1.0167056-fulltext.txt
Citation
24-1.0167056.ris

Full Text

ANALGESIC AND ANTIBIOTIC PRESCRIBING DECISIONS OF BRITISH COLUMBIAN DENTISTS AND ENDODONTISTS  by Rene Buttar  B.Sc., The University of British Columbia, 1999 D.M.D., The University of British Columbia, 2005  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF  MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Craniofacial Science)  THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver)  November 2014  © Rene Buttar, 2014   ii Abstract The problems associated with a global increase in antibiotic use and prescription opioid abuse have been well documented.  The aim of this study was to assess the prescribing decisions of general dentists and endodontists in British Columbia regarding analgesics and antibiotics in clinical scenarios that involve endodontic disease.  An additional aim was to determine whether gender, clinical experience, or the practice location of the clinician impacted their decision-making.    A four-page survey was developed and distributed to half of the general dentists in Vancouver, British Columbia (n=284) and all of the endodontists in British Columbia (n=51).  The survey began with some basic demographical questions, continued with seven different clinical scenarios, and concluded with a table that listed a number of different endodontic diagnoses.  The participants were asked questions regarding their decisions to recommend or prescribe analgesics or antibiotics. The response rate to the survey was 49.2%.  72.0% of endodontists responded, as compared to 44.8% of general dentists.  A substantial proportion of clinicians prescribed opioid analgesics and antibiotics in the various clinical scenarios.  The prescription of opioid analgesics ranged from 3.6% - 46.8% over the various scenarios. The prescription of antibiotics ranged from 4.8% - 88.4%.  General dentists reported prescribing opioid analgesics and antibiotics more often than endodontists.  However, the respondents to our survey prescribed antibiotics less frequently than those of a 1996 survey conducted in the USA.  Gender, clinical experience, and practice location did not seem to impact the decision to prescribe opioid analgesics or antibiotics.         iii Preface  The research question was identified and designed by Dr. Rene Buttar under the guidance of Dr. Jeffrey Coil.  Dr. Buttar developed the survey under the guidance of the supervising committee.  The survey was distributed and subsequently collected by Dr. Buttar.  Dr. Buttar analyzed the data under the guidance of Dr. Jolanta Aleksejuniene.  The relative contribution of the collaborators in this project was:  Dr. Rene Buttar 60%, Dr. Jeffrey Coil 15%, Dr. Jolanta Aleksejuniene 15%, Dr. Ya Shen 10%.  UBC Research Ethics Board approval was obtained and the certificate number was H13-00606.   iv Table of Contents  Abstract .......................................................................................................................................... ii Preface ........................................................................................................................................... iii Table of Contents ......................................................................................................................... iv List of Tables ............................................................................................................................... vii List of Figures ............................................................................................................................. viii List of Abbreviations ................................................................................................................... ix Acknowledgements ........................................................................................................................x Dedication ..................................................................................................................................... xi Chapter 1: Introduction ................................................................................................................1 1.1 Pain and analgesics ............................................................................................................ 1 1.1.1 Traditional NSAIDs .................................................................................................... 3 1.1.2 Acetaminophen ........................................................................................................... 3 1.1.3 Opioids ........................................................................................................................ 4 1.1.3.1 Prescription and misuse of prescription opioids .................................................. 6 1.1.4 Corticosteroids ............................................................................................................ 8 1.2 Infection and antibiotics ..................................................................................................... 8 1.2.1 ß-Lactam antibiotics.................................................................................................... 8 1.2.2 Clindamycin ................................................................................................................ 9 1.2.3 Metronidazole ............................................................................................................. 9 1.2.4 Prescription of antibiotics ........................................................................................... 9 1.2.5 Antibiotic resistance.................................................................................................. 10   v 1.3 Endodontic disease and its progression ........................................................................... 12 1.4 The appropriate use of analgesics in endodontics............................................................ 13 1.4.1 Past surveys on analgesics in endodontics ................................................................ 16 1.5 The appropriate use of therapeutic antibiotics in endodontics ......................................... 17 1.5.1 Past surveys on antibiotics in endodontics................................................................ 17 Chapter 2: Rationale and Hypothesis ........................................................................................20 Chapter 3: Materials and Methods ............................................................................................21 3.1 Development of the survey .............................................................................................. 21 3.2 Sample selection .............................................................................................................. 22 3.3 Distribution and collection of surveys ............................................................................. 22 3.4 Analysis of data................................................................................................................ 24 Chapter 4: Results........................................................................................................................25 4.1 Scenario A ........................................................................................................................ 30 4.2 Scenario B ........................................................................................................................ 33 4.3 Scenario C ........................................................................................................................ 36 4.4 Scenario D ........................................................................................................................ 39 4.5 Scenario E ........................................................................................................................ 42 4.6 Scenario F ........................................................................................................................ 45 4.7 Scenario G ........................................................................................................................ 48 4.8 Comparisons between general dentists and endodontists in the various clinical scenarios ………………………………………………………………………………………….. 51 4.9 Diagnosis-based antibiotic prescription ........................................................................... 52 Chapter 5: Discussion ..................................................................................................................59   vi 5.1 Analgesics ........................................................................................................................ 59 5.2 Antibiotics ........................................................................................................................ 61 5.3 Response rates and potential biases of the survey ........................................................... 65 5.4 Novelty of the present research ........................................................................................ 68 5.5 Significance, future directions, limitations ...................................................................... 68 Chapter 6: Conclusions ...............................................................................................................70 Bibliography .................................................................................................................................71 Appendices ....................................................................................................................................77 Appendix A ............................................................................................................................... 77 Appendix B ............................................................................................................................... 78    vii List of Tables  Table 1 - Response rates............................................................................................................... 25 Table 2 - Clinical experience of the respondents ......................................................................... 27 Table 3 - Comparison of clinical experience between respondents and non-respondents ........... 29 Table 4 - Results from Scenario A ............................................................................................... 32 Table 5 - Results from Scenario B ............................................................................................... 35 Table 6 - Results from Scenario C ............................................................................................... 38 Table 7 - Results from Scenario D ............................................................................................... 41 Table 8 - Results from Scenario E ............................................................................................... 44 Table 9 - Results from Scenario F ................................................................................................ 47 Table 10 - Results from Scenario G ............................................................................................. 50 Table 11 – Antibiotic prescription results from the diagnosis-based table .................................. 55 Table 12 - Comparison of antibiotic prescription from 1996 (n=651) and 2013 (n=152) studies 57    viii List of Figures  Figure 1 - Gender distribution of the respondents ....................................................................... 26 Figure 2 - Dental office location distribution of the respondents ................................................ 26 Figure 3 - Comparison of gender between respondents and non-respondents ............................ 28 Figure 4 - Comparison of practice location between responding and non-responding general dentists .......................................................................................................................................... 29 Figure 5 - Comparison of opioid prescription between general dentists and endodontists in the various clinical scenarios .............................................................................................................. 51 Figure 6 - Comparison of antibiotic prescription between general dentists and endodontists in the various clinical scenarios ........................................................................................................ 52 Figure 7 - Comparison of antibiotic prescription between general dentists and endodontists in the various diagnoses presented in the table ................................................................................. 56 Figure 8 - Comparison of antibiotic prescription between 1996 and 2013 studies ...................... 58    ix List of Abbreviations  CDSBC - College of Dental Surgeons of British Columbia MRSA - Methicillin-resistant Staphylococcus aureus NNT – Number needed to treat NSAIDs - Non-steroidal anti-inflammatory drugs PGD2 - Prostaglandin D2 PGE2 - Prostaglandin E2 PGF2α - Prostaglandin F2α PGI2 - Prostacyclin I2 TRPV1 – Transient receptor potential cation channel V1    x Acknowledgements  I offer my gratitude to the faculty and staff at the Faculty of Dentistry at the University of British Columbia, especially those in the Division of Endodontics.  I owe particular thanks to Dr. Jeffrey Coil for mentoring me since I was a student in dental school.  You have selflessly guided me in my work and I truly appreciate all of your efforts.  I continue to learn from you everyday. I thank Dr. Jolanta Aleksejuniene for spending countless hours reviewing the results and statistics from the study.  You have motivated me to work as hard as I could on my research from the first moment that we met. I also thank Dr. Ya Shen, who has such a gentle and caring approach to everything she does.  Your commitment to your students is inspiring. In addition, it’s been a privilege to learn from Dr. Markus Haapasalo, whose philosophies on endodontics have led me to critically assess how we approach different clinical situations. Finally, I would like to thank my parents for guiding me towards all of my successes.      xi Dedication  I dedicate this to my loving wife, Anita, and my wonderful children, Anya and Julian.  It is only with their support that I have been given the opportunity to achieve my goals.   1 Chapter 1: Introduction  Commonly prescribed medications in the field of dentistry include analgesics, to relieve pain, and antibiotics, to treat and prevent infection.  Both types of medications are classified based on their structure and mechanism of action (1).    1.1 Pain and analgesics The International Association for the Study of Pain defines pain as “an unpleasant sensory and emotional experience associated with actual or potential damage, or described in terms of such damage” (2).  Pain is subjective, and individuals may experience similar levels of tissue damage differently (2).  There are even individuals who may experience pain without the presence of tissue damage (2).   In general, pain results from the stimulation of nociceptors, also known as pain receptors.  This can be accomplished by thermal, chemical, or mechanical stimuli (3).  The transmission of such stimuli to the cerebral cortex results in the sensation of pain (4).  However, pain is much more complicated and has emotional, cognitive, and affective components (3).  The complexity of pain has been illustrated by showing that different regions of the brain are active in different individuals during the pain experience (5).  It is thought that no one area is necessary or sufficient for experiencing pain (3).  There are many different types of receptors and ion channels located on neurons that may facilitate the transmission of pain signals (6).  These include various types of G-protein coupled receptors, voltage gated ion channels, transient receptor potential channels, and others (6).    2 Different ligands or stimuli are responsible for activating the different receptors and ion channels on neurons, and thus modulating pain (6).   Tissue damage results in the release of inflammatory mediators.  These mediators initiate an immune response by increasing blood flow, vascular permeability, and leukocyte adhesion in the area of injury (3).  Many of these inflammatory mediators, such as endothelin, certain neuropeptides, and prostaglandins, act as potent activators of nociceptors to cause pain (3,6,7).  Prostaglandins are one type of inflammatory mediator that can also increase the sensitivity of nociceptors, a phenomenon known as peripheral sensitization (1).  This is mostly accomplished by prostaglandin E2 (PGE2) and prostacyclin I2 (PGI2) (8,9).  Centrally within the brain and spinal cord, PGE2, PGD2, PGI2, and PGF2 increase the excitability of the interneurons that are part of the pain pathway (10).  This is known as central sensitization (1).  The complexity of pain has resulted in a number of different pharmaceutical approaches to reducing pain levels, each targeting different areas along the pain pathway.  Some drugs target the inflammatory mediators that sensitize or activate nociceptors (3).  Others block the transmission of the pain signal before it reaches the central nervous system (3).  Some target the central nervous system and alter the way the signals are received and interpreted (3).  Non-steroidal anti-inflammatory drugs (NSAIDs) are examples of analgesics that primarily act peripherally, while opioids are examples of analgesics that primarily act centrally. Aspirin, NSAIDs, acetaminophen, and opioids are the most commonly used analgesics; other medications such as corticosteroids, antidepressants, muscle relaxants, local anaesthetics, and anxiolytics also have indications as analgesics (4).     3 1.1.1 Traditional NSAIDs There are a number of different NSAIDs that vary chemically, but have the same effect on the pain pathway.  These include acetylsalicylic acid (eg. Aspirin), ibuprofen (eg. Advil, Motrin), naproxen (eg. Aleve), ketorolac (eg. Toradol), and others.  The analgesic effect of NSAIDs arises from their ability to inhibit cyclooxygenase, an enzyme that is involved in the prostaglandin synthetic pathway (1).  The inhibition of cyclooxygenase results in lower prostaglandin levels, and, therefore, lower pain levels.  Most are effective in cases of mild to moderate pain (1). Prostaglandins have a number of other important physiological roles such as protecting the gastric mucosa and promoting platelet aggregation (1).  The use of NSAIDs for analgesia can result in side effects on the gastrointestinal tract, kidneys, and platelets (1).  The most common side effect is the development of gastric or intestinal ulcers (11).  It has been shown that the risk in gastrointestinal bleeding with NSAIDs use is higher in patients that smoke, in patients that have experienced gastrointestinal bleeding, and in patients taking anti-coagulants (11).  The risk is also higher if patients are taking NSAIDs for a long duration, or taking multiple NSAIDs.   In Canada, some NSAIDs can be purchased without a prescription.    An example is ibuprofen in doses of 400mg or less.  Others require a prescription, such as ketorolac, or ibuprofen in doses larger than 400mg.   1.1.2 Acetaminophen Acetaminophen is also an analgesic used in cases of mild to moderate pain.  It also inhibits the function of cyclooxygenase; however, it is not very effective at this inhibition in the presence of peroxides, such as in areas of inflammation (1).  The exact analgesic mechanism of   4 action of acetaminophen has not been known until recently.  It was shown that acetaminophen is metabolized in the brain by a fatty acid amide hydrolase to a molecule related to lipoamino acids (12).  As with lipoamino acids, this active metabolite of acetaminophen can interact with transient receptor potential cation channel V1 (TRPV1) receptors in the brain.  It has been shown that it is through this interaction that acetaminophen exerts its analgesic effect (13).  Acetaminophen has a low incidence of gastrointestinal side effects as compared to traditional NSAIDs.  However, acute overdose can result in severe liver damage (1).  A recent study showed that acetaminophen overdose account for 42% of all cases of acute liver failure in the USA (14).  It is interesting to note that almost half of the cases of acetaminophen overdose were unintentional.  Additionally, more than one quarter of these overdose cases resulted in death.  Perhaps one contributing factor is that, in Canada, acetaminophen can be purchased without a prescription.  1.1.3 Opioids The resin from Papaver somniferum, the opium poppy, has been used in medicine since the 3rd century (4).  It was initially used to treat dysentery (15).  Later, its powerful analgesic effects were discovered.  Opium contains over 20 alkaloids, including morphine and codeine (1).  Opiates are a group of compounds that include these naturally occurring alkaloids and semi-synthetic derivatives of morphine such as oxycodone (1).  Opioids are any compounds, regardless of their structure, that act like opiates (1).  This includes meperidine, fentanyl, methadone, and endogenous peptides, such as endorphins, enkephalins and dynorphins (1). The analgesic and euphoric effects of opioids has been known for many years, but the mechanism was not understood until the 1970s (1).  Three separate opioid receptors were   5 identified and named , , and  (16).  They were found to be present in the brain and spinal cord, but also in vascular, cardiac, respiratory, and gastrointestinal tissues (1).  The binding of these receptors results in the effects seen with opioids.  Certain opioids have a tendency to bind certain opioid receptors; however, they do have the ability to cross-react and bind the other receptors also (1).  The analgesic effect of opioids is mostly a result their effect on the receptors in the brain and spinal cord.  They are the mainstay of treatment for severe pain (15).  Other effects that occur from the binding of opioid receptors peripherally include respiratory depression, constipation, and pupil constriction, amongst others (15).  These effects are dependent on the type of opioid and the dose used.   Long-term use of opioids can lead to tolerance, dependence, and even addiction (1).  Tolerance is the progressive loss of the effect of the opioid (1).  It can be overcome by increasing the dose of the opioid (1).  This tolerance is reversible after cessation of the opioid (1).  This cessation does lead to withdrawal symptoms such as agitation, hyperalgesia, diarrhea, pupillary dilation and dysphoria (1).  Dependence is the requirement of the opioid to prevent such symptoms (1).  In Canada, almost all opioids require a prescription.  Combinations that include 8mg of codeine per dose or less are an exception.  For example, Tylenol #1, which is composed of 350mg of acetaminophen and 8mg of codeine, does not require a prescription.  Most opioids are part of the Controlled Prescription Program and are required to be prescribed using a duplicate prescription form.  This is to “prevent forgeries and inappropriate prescription” (17).  Drug combinations that include less than 60mg of codeine per dose are an exception (17).  For example, Tylenol #3, which is composed of 350mg and 30mg codeine, does not require a   6 duplicate prescription.  However, Tylenol #4, which is composed of 350mg acetaminophen and 60mg codeine, does require practitioners to fill out a duplicate prescription.  Any dose of codeine when prescribed as a single entity requires a duplicate prescription (17).  This also applies to the other opioids occasionally prescribed in dentistry such as Percocet (325mg acetaminophen and 5mg oxycodone) and Percodan (325mg ibuprofen and 5mg oxycodone) (17).  1.1.3.1 Prescription and misuse of prescription opioids     The USA and Canada are first and second countries in the world, respectively, with regards to the highest levels of prescription opioid consumption (18,19).  One report suggested that the amount of prescription opioid use in Canada in 2007-2009 was over double that in 2001-2003 (20).  A study in 2010 estimated that 23 defined daily doses of opioids per 1000 people per day were dispensed in Canada (21).  This study analyzed the records of pharmacies in Canada and showed that the prescription of opioids increased by 13% in the period from 2005-2010.  This same study showed significant differences amongst different provinces in Canada.  Pharmacies in Alberta dispended the most opioids in total, almost three times that of Quebec which dispensed the least.  Ontario dispensed the most “strong” opioids such as oxycodone during this period.  British Columbia ranked amongst the top four in total opioid dispensing, and amongst the top three in codeine combination dispensing (21).  The data on increasing opioid use has led to significant research on the possible causes and consequences.  Opioids are a very important and beneficial analgesic in medicine (15).  However, as previously mentioned, their use can lead to dependence and addiction.  Some believe that the increase in prescriptions is related to the non-medical use of the prescription medication (22,23).     7 There have been many investigations in the USA regarding the prevalence of non-medical prescription opioid use (24-26).  In 2003, the National Survey on Drug Use and Health found that 5% of household residents over the age of 12 abused prescription opioids (24).  The National Institute of Drug Abuse reported that upwards of 9% of secondary school students abused prescription opioids in 2004 (25).  This was second in prevalence only to marijuana.  Another study in Michigan showed that 9% of 14-20 year olds reported non-medical prescription opiate use in the previous year (26).   In Canada, less research has been completed assessing the prevalence of substance abuse than in the USA.  A recent study in 2013 showed that 6% of adults and 16% of students in Ontario used non-medical prescription opioids in the previous year (27).  Overseas in Australia, a 2013 study showed that 35% of injection drug users had used over-the-counter codeine recently, and that 52% of this group had used more than the recommended dose (28). Possibly due to this increase in opioid use, overdoses and emergency room visits due to non-medical prescription opioid use have also increased (20,29-31).  In addition, the number of people seeking treatment for opioid addiction due to the use of prescription opioids is also increasing (32).  A 2004 study showed the number of people seeking treatment for opioid detoxification at the Centre for Addiction and Mental Health in Toronto was steadily increasing (32).  This increase was due to non-medical use of prescription opioids, not due to drugs such as heroin.  Most people took these medications orally; however, some did crush the medication and either injected or inhaled the medication (32).    8 1.1.4 Corticosteroids Corticosteroids, such as dexamethasone, are another class of medication that can be used as an analgesic.  As with NSAIDs, they inhibit the production of various inflammatory mediators, reducing levels of inflammation and pain (33).  They differ from NSAIDs in the fact that they have multiple sites of action, and end up decreasing a broader range of cytokines.  As they do affect many cellular processes throughout the body, they have a wide range of side effects (1).     1.2 Infection and antibiotics Humans are in constant contact with microorganisms.  Some reside on the skin and mucosal linings of the body and are considered normal flora.  Other pathogenic microorganisms are often present.  The body can often defend itself from these microorganisms.  When the body cannot defend itself, the microorganisms multiply and result in an infection.  Antibiotics are a type of medication that are used to treat infections.  They are classified based on their chemical structure and their proposed mechanism of action (1).  Each antibiotic is only effective against certain microorganisms.  In addition, each antibiotic has a different ability to penetrate certain areas of the body (1).  As a result, infections in different parts of the body are treated with different types of antibiotics, as are infections with different types of microorganisms.     1.2.1 ß-Lactam antibiotics ß-lactam antibiotics lyse bacteria by inhibiting the synthesis of peptidoglycan, the polymer which forms the bacterial cell wall (34).  Gram-positive bacteria have a thick outer   9 peptidoglycan layer (1).  Gram-negative bacteria have a thinner peptidoglycan layer that is covered by an outer membrane (1).  Consequently, ß-lactam antibiotics are more effective against gram-positive bacteria (1).  However, the outer membrane of some gram-negative bacteria can be penetrated, and in these cases ß-lactams can be effective (1).  Examples of ß-lactam antibiotics include Penicillin and Amoxicillin.    1.2.2 Clindamycin Clindamycin is a type of lincosamide antibiotic (1).  It binds the 50S subunit of bacterial ribosomes, suppressing bacterial protein synthesis (1).  This effect is a bacteriostatic one, as opposed to bactericidal.  When compared to Penicillin or Amoxicillin, it has a much wider spectrum; it is effective against more gram-negative and anaerobic bacteria than the ß-lactam antibiotics (1).   1.2.3 Metronidazole Metronidazole is an antimicrobial that is effective against some protozoans in addition to some bacteria (1).  Once intracellular, it accepts electrons and becomes activated, destroying cell DNA along with other cellular components (1).  With regards to bacteria, it is only effective against anaerobic bacteria.  The reason for this is that mechanisms that activate Metronidazole rely on cellular components that are only present in anaerobic bacteria (1).  1.2.4 Prescription of antibiotics Globally, antibiotics are a widely used medication.  North America and Japan account for the majority of the world’s antibiotic use (35).  The United States of America accounts for 50%   10 of the world’s antibiotic use.  To put this more in context, 47 million prescriptions for antibiotics were written in the United Kingdom in 1998, a country that accounts for only 2% of the world’s antibiotic use (35,36).  1.2.5 Antibiotic resistance Antibiotics have been widely used to combat infectious diseases since their discovery.  A consequence of widespread antibiotic use is the emergence of bacterial resistance to certain antibiotics (35).  The prevalence of antibiotic resistance is increasing worldwide (37).  There is strong evidence to suggest that antibiotic use can cause this resistance (35). Bacterial species exist in various strains.  Strains are genetic variants of the same species of bacteria.  Different strains of a certain species of bacteria may differ in their pathogenicity.  In addition, different strains may respond differently to antibiotics.  A strain is considered resistant to an antibiotic when a normally effective concentration of that antibiotic has no affect on it (38). Bacteria may be intrinsically resistant to antibiotics, as aerobic bacteria are resistant to metronidazole, or they may acquire this resistance through either a spontaneous mutation or a transfer of genetic material (35).  It is the acquired resistance that concerns use because the improper use of antibiotics can lead to such type of resistance.   When bacteria are exposed to changing environments or medications that threaten their survival, they can mutate to avoid being killed.  Specific to antibiotic resistance, bacteria can acquire the ability to destroy the antibiotic, reduce the uptake of the antibiotic, increase the excretion of the antibiotic, and change the target of the antibiotic so that that it doesn’t bind (35).  If the dose of antibiotics is too weak, or if it is used for too long, the chance of such mutations increases (38).  After such a mutation, the bacteria can survive and divide in the presence of an   11 antibiotic it has achieved resistance against.  It can then transfer this resistance to other strains or species of bacteria by several mechanisms including conjugation, transduction, and transformation (35).  Conjugation is most common method and involves the transfer of DNA by plasmids, transduction is the transfer of DNA by bacteriophages, and transformation is the acquisition of naked DNA (38).  Globally, the impact of bacterial resistance of antibiotics has been very substantial.  It is evident in hospitals where normally commensal bacteria are leading to serious nosocomial infections.  These infections can lead to increased clinical complications, length of stay in the hospital, morbidity and mortality (39).  This has already led to some infectious conditions being untreatable (35).  In 1997, it was reported that such infections resulted in over 150,000 deaths in the United States (37). Staphylococcus aureus is the bacteria most well known for its resistance to antibiotics.  It can be occasionally found on the skin, in the oral cavity, and in the respiratory tract.  In 1944, 95% of S. aureus isolates were susceptible to Penicillin (35).  Currently, less than 10% are susceptible to Penicillin (35).  The resistance first presented clinically in the 1950s, at which time ß-lactamase-stable antibiotics, such as Methicillin, were developed (35).  Next came strains of S. aureus that were resistant to Methicillin, known as Methicillin-resistant Staphylococcus aureus (MRSA) (35).  These strains were then treated with gentamycin.  In the 1970’s, Gentamycin-resistant MRSA strains were identified and treated with Vancomycin (35).  There is current evidence of intermediate resistance of certain S. aureus strains to Vancomycin, and such strains cannot be effectively treated (35).  The degree of bacterial resistance varies from one country to another.  The percentage of MRSA (of all S. aureus isolates) is 70% in Japan, 28% in the U.S., and less than 1% in Scandinavia (35).   12 In addition to S. aureus, there are many bacteria that are found in the oral cavity that have been shown to have developed antibiotic resistance.  Many α-hemolytic streptococci, including S. salivarius, S. oralis, S. mitis, and S. pneumoniae have shown resistance to Penicillin (40).  S. pneumoniae can cause pneumonia, otitis media, and bacterial meningitis.  In certain countries, upwards of 50% of isolates of S. pneumoniae are resistant to Penicillin (35).  Many of these are also resistant to other antibiotics that are commonly used against S. pneumoniae.  The presence of oral commensal bacteria resistant to antibiotics has been shown in many countries throughout the world (40).   1.3 Endodontic disease and its progression Endodontics is defined as “the specialty in dentistry that is concerned with the prevention, diagnosis, and treatment of diseases or injuries to the dental pulp” (41).  Such diseases or injuries involve inflammation due to exposed dentin, deep restorations, dental caries, or dental trauma (42).  Prior to any endodontic therapy, the disease needs to be diagnosed to ensure that treatment is necessary.  Endodontic diagnoses are given for both the pulp within the tooth and the periapical tissues outside of the tooth. With regards to the pulp, the mildest inflammation is known as reversible pulpitis (43).  In such cases the pulp returns to normal after the cause of the inflammation is removed, and endodontic therapy is not required.  As the pulp becomes more compromised, the condition is no longer reversible and endodontic therapy is indicated.  This as known as irreversible pulpitis, and this may be symptomatic or asymptomatic (43).  With progression of pulp deterioration pulp death occurs, and this is known as pulp necrosis (43).  Again, endodontic therapy is indicated.   13 In cases of necrosis where bacteria have access to the dental pulp, they may travel through the root canal system, exit the root via various channels, and cause inflammation in the periradicular tissues (3).  Depending on whether or not the tooth is painful to biting, percussion or palpation, this extraradicular inflammation is initially known as either symptomatic or asymptomatic apical periodontitis (43). In some instances, there is a severe inflammatory reaction as the body’s defenses are struggling to control the rapid growth of bacteria.  A swelling can develop, and this is known as an acute apical abscess (43).  This can be very painful.  As the periapical inflammation becomes more chronic, a sinus tract may form.  This is often not painful and the periapical diagnosis is considered to be a chronic apical abscess (43).   1.4  The appropriate use of analgesics in endodontics Patients with pulpal or periapical disease may or may not experience pain (41).  Certain conditions such as symptomatic irreversible pulpitis are more likely to cause moderate to severe pain, while others such as pulp necrosis may present on routine examination without any symptoms at all.  A recent meta-analysis of 72 studies found that 81% of patients requiring endodontic treatment experienced pretreatment pain (44).  The average pretreatment pain severity on a scale out of 100 was found to be 54 in this study.  Pain from pulpal disease should not be treated solely by pharmacological methods (45).  Endodontic treatment is effective in treating pain when associated with pulpal disease, regardless of whether or not analgesics are prescribed (45).  This is a result of decreasing local tissue pressure, decreasing inflammatory mediator concentrations, and severing terminal endings of nociceptive sensory neurons (46).  With the source of inflammation removed from within the tooth, the inflammation in the periapical tissues subsides and the body begins to heal.  Pak and White, in their study, found that   14 one week after endodontic treatment, 11% of patients still experienced pain (44).  However, the mean severity of pain was now 5 on a scale out of 100. Regardless of the pretreatment diagnosis, post-treatment pain may occur in 25-40% of all endodontic cases (47,48).  A positive correlation has been found between the presence of preoperative pain and the incidence of postoperative pain (49,50).  That being said, it is very difficult to determine which patients will experience pain.  It is also difficult to determine what level of postoperative pain patients will experience.  As a result, analgesics are often prescribed to manage any pain that may develop. People may have misconceptions about what analgesics work well to control pain.  It may be assumed that medications requiring a prescription are more effective than those bought “over the counter”.  The Pain Research Unit at the University of Oxford conducted a series of systematic reviews of randomized, double-blinded, single dose studies of patients in moderate to severe pain (47,51).  From their findings they developed the “Oxford league table of analgesic efficacy” (Appendix A).  It lists many analgesics and describes their efficacy using two parameters.  First, it states the percentage of people taking the medication that experience a greater than 50% reduction in their pain.  Second, it states the NNT, or number of people needed to treat for one person to have a significant reduction in pain when compared to the control.  For example, for Ibuprofen (400mg) it states that 55% of people achieve at least 50% pain relief, and that the NNT is 2.5.  This means that 55% of people in acute pain taking 400mg of Ibuprofen will have their pain reduced by at least 50%, and that 2.5 people need to take this medication in order for at least one person to have a significant reduction in pain.  There are some problems with the validity of the table, such as the small sample sizes in some of the studies used.  However, it can be useful in helping determine what analgesics to recommend or prescribe.  The   15 table shows that NSAIDs such as ibuprofen are very effective at larger doses.  They are more effective than acetaminophen, medications combining acetaminophen and codeine, and even medications combining acetaminophen and oxycodone.  More specific to dentistry, a recent systematic review concluded that NSAIDs are effective for treating endodontic pain (47). Keiser and Hargreaves in their review (45) suggested that every dentist should have an approach to dealing with patients in pain.  Such an approach for endodontics has been described in the literature and is generally supported.  Following endodontic therapy, they suggested that non-narcotic analgesics should be used to their maximal effect prior to incorporating any opioids.  This will result in effective pain management and avoidance of some of the consequences of opioid use.   For mild pain, low doses of NSAIDs should be used (45).  If the pain is moderate, the dosage of the NSAIDs should be increased (45). If that does not relieve pain, a combination of NSAIDs and acetaminophen should be used (45).  It has been shown that the administration of such a combination results in less postoperative endodontic pain than if either medication was taken alone (52).  If that still fails to relieve the pain, consider NSAIDs and a combination of acetaminophen and codeine (45).  However, there is evidence that the combination of ibuprofen and acetaminophen is more effective than combinations using codeine (53).  If the pain is severe, one may consider NSAIDs and a combination of acetaminophen and oxycodone (45). For patients unable to tolerate NSAIDs, the approach indicates that acetaminophen should be the first medication used (45).  As pain levels intensify, a combination of acetaminophen with codeine can be used (45).  This recommendation changes to acetaminophen with oxycodone in cases of severe pain (45).      16 1.4.1 Past surveys on analgesics in endodontics There have been a few surveys exploring analgesic recommendations and prescriptions in endodontics (54-56).  One of the first took place in 1977, when diplomats of the American Board of Endodontics were asked how they dealt with endodontic emergencies (54).  The majority of endodontists indicated that pulp removal would be indicated in all conditions.  The results also indicated that 52-67%, depending on diagnosis, would prescribe analgesics after treating the emergency.  The only exception was in cases of necrosis unaccompanied by swelling or pericementitis, where only 29% would prescribe analgesics.  The types of analgesics were not specified. A follow-up to the 1977 survey (54) was conducted in 1990 (55).  It was shown that endodontists would prescribe analgesics more often than in 1977.  NSAIDs would be prescribed in 34-51% of cases, narcotic analgesics in 18-52% of cases, and corticosteroids in 1-2% of cases.  It was shown that if a swelling was present, endodontists were more likely to prescribe narcotic analgesics than NSAIDs.      More recently in 2009, surveys were sent out to the active diplomats of the American Association of Endodontists (56).  They were asked to indicate whether or not they ever prescribed certain analgesics.  Ibuprofen was the most commonly prescribed analgesic, with 87% of respondents indicating that they prescribe Ibuprofen on occasion.  On occasion, 41% of respondents indicated that they prescribed Vicodan, which is a combination of acetaminophen and hydrocodone.  Acetaminophen was occasionally prescribed by 21% of respondents.  Tylenol #3 was occasionally prescribed by 14% of respondents.  Percocet was occasionally prescribed by 7% of respondents.        17 1.5 The appropriate use of therapeutic antibiotics in endodontics The use of antibiotics to treat endodontic conditions is limited.  Evidence has shown that root canal procedures combined with analgesic medications are sufficient for managing most symptomatic endodontic cases (57).   In cases of reversible or irreversible pulpitis there is no infection present.  In fact, there are no bacteria within the dental pulp (58).  Therefore antibiotics are not indicated to treat such cases.  Some dentists believe that antibiotics help relieve pain in cases with irreversible pulpitis.  However, the literature does not support this suggestion, and antibiotics should not be used for this purpose (59). In the majority of localized endodontic infections, antibiotics are not indicated (57).  If infection is associated with a necrotic pulp, it can be treated with debridement of the root canal system or by surgical drainage (60).  However, there are a few exceptions.   Antibiotics may be used as an adjunct to dental treatment in patients that are immunocompromised (57).  Antibiotics are also indicated if it appears that the infection is spreading (60).  Such cases may present as an extra-oral or facial space swelling, and may result in trismus or problems swallowing (57).  Antibiotics would also be indicated if signs of systemic involvement are present (60).  Such signs include fever, malaise, and lymphadenopathy (57).  Basically, antibiotics are indicated only when it appears that the host defense mechanisms need assistance in controlling infection.  1.5.1 Past surveys on antibiotics in endodontics In 1998, it was shown that 3.5 million prescriptions for antibiotics were written by dentists in the United Kingdom (40).  That is approximately three prescriptions per dentist per   18 week.  In 2000, results from another survey showed that dentists in British Columbia, Canada prescribed antibiotics, on average, 4.45 times per week (61). Some of the surveys on analgesics mentioned earlier also investigated the prescription of antibiotics by endodontists.  In 1977, Dorn et al. reported prescription rates by endodontists to be up to 15% for irreversible pulpitis, 30% for necrosis with no swelling, and 52% for necrosis with a localized swelling in which drainage was obtained (54).  It is important to note that these are all cases where antibiotics are not indicated.  In 1990, Gatewood et al. (55) found the rates for treating the same situations to be 14%, 33%, and 61%, respectively.  This study suggested a trend of endodontists writing more antibiotic prescriptions than earlier. Additional surveys have more recently investigated this topic.  In 1996, Whitten et al. sent surveys to 1000 general dentists and 500 endodontists in the US and asked a number of questions regarding their decisions in endodontic treatment (62).  One aspect enquired about whether or not they would prescribe antibiotics.  They used categories similar to Dorn et al. but included the presence or absence of symptoms in their description of the teeth being treated.  Yingling et al. used similar questions as part of their survey sent out to 3203 US endodontists (63).  Whitten et al. reported prescription rates for antibiotics, by endodontists, to be 25% for irreversible pulpitis with moderate or severe symptoms, 36% for necrosis with no swelling or symptoms, 67% for necrosis with no swelling and moderate or severe symptoms, 29% for necrosis with a chronic apical abscess, and 97% for necrosis with swelling and moderate or severe symptoms (62).  Yingling et al. reported rates in similar situations to be 13%, 19%, 54%, 12% and 99% (63).  The prescription rates reported in 2002 by endodontists were consistently lower than those reported in 1996.   19 As mentioned earlier, Whitten et al. had included general dentists into their sample.  They found that general dentists prescribed antibiotics significantly more often than endodontists in cases of irreversible pulpitis and in cases of necrosis with a chronic apical abscess (62).   Yingling et al. had some additional findings of interest (63).  The average endodontist reported to prescribe antibiotics 9.25 times per week.  The antibiotic prescribed most often was reported to be Penicillin VK, which would be prescribed by 62% as their first choice.  28% of respondents would prescribe Amoxicillin as their first choice.  Clindamycin was found to be the antibiotic prescribed most often by the respondents as their second choice.  It was also the antibiotic most often prescribed in patients allergic to Penicillin. Similarly to North American studies, high prescription patterns have been found internationally. In 2009, a survey was sent out to 508 members of the Spanish Endodontic Society (64).  Similar categories as those described by Whitten et al. were used and similar rates of antibiotic prescription were found.  In 2011, a survey sent out to dentists in Iran reported some exceptionally high prescription rates for antibiotics (65). The most pertinent findings were that 81% of respondents prescribed antibiotics for cases of irreversible pulpitis, and 11% of respondents prescribed antibiotics always after root canal treatment.      20 Chapter 2: Rationale and Hypothesis  There are a number of important facts that, when considered together, justify the need for research in this area.  First, bacterial resistance to antibiotics is increasing worldwide and it has been correlated to an increase in antibiotic prescription.  Second, the non-prescription use of opioids has become an important issue in the field of drug abuse and addiction.  Third, dentists prescribe both types of medications and it has been documented that they do so inappropriately in various regions of the world.  As no such type of study has been done in Canada, the rationale for this research is justified. The aim of this study was to assess the prescribing decisions of general dentists and endodontists in British Columbia regarding analgesics and antibiotics in clinical scenarios that involve endodontic disease. Additional aims included evaluating whether gender, clinical experience, or practice location of the clinician had any impact on their prescribing decisions.  We will also attempt to compare our results with those of others recorded elsewhere in the world.    21 Chapter 3: Materials and Methods  This study featured a survey of endodontists in British Columbia and of general dentists in the city of Vancouver, British Columbia.  They were asked to provide information pertaining to what analgesics and antibiotics they would recommend in different clinical scenarios.  The study was approved by the University of British Columbia Behavioral Research Ethics Board (H13-00606).  3.1 Development of the survey An original survey was composed and revised a number of times.  Once it was felt an adequate survey had been prepared, ten dentists were asked to fill out the survey as a pilot study.  Their feedback was obtained as to the clarity of the survey, and their suggestions were considered as further revisions were made. The final survey consisted of three parts (Appendix B).  The first part asked some basic demographical questions.  The second part presented seven different clinical scenarios.  In each scenario, it was asked whether or not an analgesic would be recommended or prescribed by the clinician.  It was then asked which analgesic would be recommended or prescribed, and at what dosage.  Additionally, it was also inquired if an antibiotic would be prescribed in each scenario.  It was asked which antibiotic would be prescribed, and at what dosage.  The third part of the survey included a table that asked the clinician whether or not they would prescribe antibiotic based on specific endodontic diagnoses.  This table was developed from one used by Whitten et al. in 1996 (62).     22 3.2 Sample selection A complete list of dentists registered with the College of Dental Surgeons of British Columbia was obtained directly from CDSBC.  This directory included 615 general dentists with offices listed in Vancouver.  It also listed 54 endodontists throughout the province. A random sample number generator was used to select half of the general dentists in Vancouver (random sampling for general dentists).  This random number generator would randomly assign the number “0” or “1” for each of the 615 dentists.  If the dentist was assigned the number “0”, they were excluded from the study.  If they were assigned the number “1”, they were included in the sample to be surveyed.  This resulted in a sample size of 284 general dentists.  It was felt that this number, although arbitrary, was representative of the total population of general dentists in Vancouver.  As the number of endodontists registered with CDSBC is much lower than the number of general dentists, it was decided to include all of the endodontists in the province (census sampling for endodontists).  However, three endodontists were excluded as they are full-time professors in the Faculty of Dentistry at the University of British Columbia.  Two of these three endodontists are closely associated to the study as they are part of the research committee.  This resulted in a revised sample size of 51 endodontists.    3.3 Distribution and collection of surveys The contact information provided in the Directory of Dentists from the College of Dental Surgeons of British Columbia (CDSBC) was initially used to determine how to distribute the survey to the dentists and endodontists included in our sample.  Most clinicians have provided   23 the mailing address, phone number, and fax number of their dental office.  In addition some have provided their office email addresses.   For the first distribution of the survey, it was sent by email to all clinicians that had an email address listed in the directory.  At the start of the email message was an introductory statement introducing the study.  If an email address was not listed, the survey was sent by fax.  The fax included a cover letter that introduced the study, similar to the email.  For clinicians who had no email address or fax number, surveys were mailed to their offices.  All practitioners were provided three options to return the completed survey; by email, by fax, or by mail. After approximately four to six weeks, it was determined who had returned completed surveys.  This was done by comparing the fax numbers and email addresses from which the completed surveys had been sent to the contact information provided in the directory.  The offices of all non-respondents were then contacted by phone.  The importance of the research was briefly explained to the staff member who answered the phone.  It was then asked what would be the preferred method to send the survey again to ensure that the dentist received it.  Based on their response, the survey was sent a second time.  It was sent by email, fax, or mail.  This may or may not have been the same method used when distributing the survey the first time. Two months after this second distribution of surveys, it was again determined who returned completed surveys.  For the third distribution, all the remaining offices were mailed a survey along with a pre-stamped return envelope.  The surveys were coded in a subtle manner.  This would allow us to know who responded to the third distribution.  This was important as we were interested in comparing the demographical data of the responders to the non-responders to assess any biases that may be present.     24 3.4 Analysis of data The data from the collected surveys was entered into a spreadsheet as completed surveys were returned.  This information was transferred to a statistical software program (SPSS, Version 21.0).  For the scenario-based questions, the parameters investigated included whether not analgesics and/or antibiotics would be recommended or prescribed, which specific medication would be recommended or prescribed, and the dosage of the medication recommended or prescribed.  For the diagnosis-based table, the prevalence of antibiotic prescription was assessed.   The survey response rate was determined.  The overall responses to the different parts of the survey were evaluated objectively.  The responses of different groups were compared using either Chi-square tests or Fischer-exact tests with the threshold of significance set at p<0.05. Endodontists were compared to general dentists.  Assuming that the average dental career spans 30 years or longer, clinicians with more than 15 years of clinical experience were compared to those with less than or equal to 15 years of clinical experience.  Female clinicians were compared with male clinicians.  General dentists from the western half of Vancouver were compared to general dentists from the eastern half of Vancouver.  This was done to see if the socio-economic level of the patients had any effect on prescription decisions of their dentists (the western half of Vancouver is a much more affluent area than the eastern half).  An additional analysis was completed for the diagnosis-based table; the responses from our survey were also compared to those received by Whitten et al. in 1996. Non-response analysis was completed by comparing the age, clinical experience, and practice location of non-respondents to respondents.    25 Chapter 4: Results  Originally, the sample for this study was to include 284 general dentists in Vancouver and 51 endodontists within British Columbia.  After attempting to distribute the surveys, it was determined that some clinicians had to be excluded from the sample for various reasons.  Twenty-five general dentists were excluded.  Thirteen of these could not be contacted by phone, email, or fax.  This was either due to the contact information listed with the CDSBC being missing or incorrect.  An additional five were no longer working in Vancouver.  The remaining seven indicated that they were not practicing under the scope of general dentistry.  One endodontist was excluded as she was no longer working in British Columbia.  This resulted in a revised sample consisting of 259 general dentists and 50 endodontists. With a total of 152 completed surveys being returned, the overall response rate was 49.2% (Table 1).  44.8% of all general dentists returned completed surveys, as compared to 72.0% of all endodontists.    Table 1 - Response rates  Number of Response  respondents rate General dentists 116 44.8% Endodontists 36 72.0% Overall 152 49.2%  Demographical questions were asked at the beginning of the survey that inquired about the years of clinical experience and gender of the clinician.  If the clinician was a general dentist, a question was asked inquiring about the location of their dental practice.   26 With regards to gender, 34.4% of the respondents were female and 65.6% of the respondents were male (Figure 1).  Figure 1 - Gender distribution of the respondents   With regards to location of their dental office, 79.6% of responding general dentists practiced on the western half of Vancouver and 20.4% practiced on the eastern half of Vancouver (Figure 2).    Figure 2 - Dental office location distribution of the respondents  34.4%65.6%GenderFemaleMale20.4%79.6%Practice locationEastern half ofVancouverWestern half ofVancouver  27 With regards to clinical experience, the average respondent had 21.20 ± 11.82 years of clinical experience (Table 2).  An independent t-test was used to compare the clinical experience of different groups that were going to be evaluated in this study.  It was found that there was no significant mean difference in clinical experience between the general dentists and the endodontists (Independent t-test, p=0.524).  There was also no significant difference in clinical experience between the general dentists working on the western half of Vancouver and those working on the eastern half of Vancouver (Independent t-test, p=0.839).  However, it was found that the male clinicians had significantly more clinical experience than the female clinicians (Independent t-test, p<0.001).  The average female clinician had 15.80 ± 10.28 years of clinical experience, while the average male clinician had 23.98 ± 11.67 years of clinical experience.  Table 2 - Clinical experience of the respondents  Years of clinical experience p-value ‡ General dentists 20.79 ± 10.97 p=0.524 Endodontists 22.49 ± 14.31 Female 15.80 ± 10.28 p<0.001 Male 23.98 ± 11.67 Western half of Vancouver 21.01 ± 10.76 p=0.839 Eastern half of Vancouver 20.43 ± 12.29 Overall 21.20 ± 11.82  ‡ Independent t-test     To see if the respondents were representative of the original sample, comparisons were made between the respondents and non-respondents.  Chi-squared tests were used to compare gender and practice location of respondents and non-respondents, while a two-sided t-test was used to compare clinical experience.  There was no significant difference between the   28 respondents and non-respondents with regards to gender (Chi-squared test, p=0.750) (Figure 3).  However, proportionally more of the respondents worked in the western half of Vancouver when compared to the non-respondents  (Chi-squared test, p=0.022) (Figure 4).  With regards to years of clinical experience, there was no significant difference between the respondents and the non-respondents (Independent t-test, p=0.790) (Table 3).   Figure 3 - Comparison of gender between respondents and non-respondents  - Chi-squared test, p=0.750        66% 64%34% 36%020406080100120140160Respondents Non-respondentsNumber ofcliniciansFemaleMale  29 Figure 4 - Comparison of practice location between responding and non-responding general dentists   - Chi-squared test, p=0.022  Table 3 - Comparison of clinical experience between respondents and non-respondents  Years of clinical experience p-value ‡ Respondents 21.20 ± 11.82 0.790 Non-respondents 21.55 ± 10.82  ‡ Independent t-test     The aim of this study was to assess the prescribing decisions of general dentists and endodontists in British Columbia regarding analgesics and antibiotics in clinical scenarios that involve endodontic disease.  Each scenario will now be evaluated individually.  80% 67%20%33%020406080100120140160Respondents Non-respondentsNumber cliniciansEastern half ofVancouverWestern half ofVancouver  30 4.1 Scenario A A patient calls your office and reports a severe toothache.  The pain is constant and worsens when biting on the tooth or touching the tooth.  There is no swelling according to the patient.  Due to certain circumstances, the patient cannot come into your office for immediate treatment.  The results are summarized in Table 4.  Overall, 94.6% of respondents would recommend or prescribe an analgesic in this scenario. No significant differences were found in this regard between any of the comparison groups: general dentists vs. endodontists (Fisher’s exact test, p=1.000), <15 vs. >15 years of clinical experience (Fisher’s exact test, p=0.258), female vs. male clinicians (Fisher’s exact test, p=0.444), practice in western half vs. eastern half of Vancouver (Fisher’s exact test, p=0.603).  When considering the specific classification of analgesic, 68.6% of respondents indicated that they would prescribe or recommend a non-opioid analgesic.  25.5% indicated that they would prescribe an opioid analgesic.  No significant differences were found between any of the comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.980), <15 vs. >15 years of clinical experience (Chi-squared test, p=0.346), female vs. male clinicians (Chi-squared test, p=0.658), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.798).  Overall, 37.0% of respondents indicated that they would prescribe an antibiotic in this scenario. Clinicians with >15 years of clinical experience indicated that they would prescribe an antibiotic 46.6% of the time, which was significantly more often than those with <15 years of clinical experience (Chi-squared test, p=0.002).  No significant differences were found in any of the other comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.435),   31 female vs. male clinicians (Chi-squared test, p=0.235), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.402). When considering the different types of antibiotics, Amoxicillin was most common being prescribed by 29.2% of respondents.  This was followed by Penicillin, which was prescribed by 7.3% of respondents. No significant differences were found between any of the comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.321), <15 vs. >15 years of clinical experience (Chi-squared test, p=0.085), female vs. male clinicians (Chi-squared test, p=0.641), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.639).   32 Table 4 - Results from Scenario A  Overall GD Endo p-value   ≤15 yrs >15 yrs p-value   Female Male p-value   West East p-value A Yes 94.6% 94.7% 94.4% 1.000†   98.1% 92.3% 0.258†   92.0% 95.9% 0.444†   95.4% 91.3% 0.603† N       A No 5.4% 5.3% 5.6%   1.9% 7.7%   8.0% 4.1%   4.6% 8.7% L       G Non-opioids 68.6% 68.3% 69.7% 0.980*   71.4% 67.1% 0.346*   66.7% 69.7% 0.658*   68.8% 65.2% 0.798* E       S Opioids 25.5% 26.0% 24.2%   26.5% 24.7%   25.0% 25.8%   26.3% 26.1% I       C Strong opioids 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% S                                          A Yes 37.0% 38.7% 31.4% 0.435*   20.4% 46.6% 0.002*   30.0% 40.0% 0.235*   40.0% 30.4% 0.402*    N       T No 63.0% 61.3% 68.6%   79.6% 53.4%   70.0% 60.0%   60.0% 69.6% I       B Amoxicillin 29.2% 32.4% 18.8% 0.321*   17.4% 35.6% 0.085*   26.1% 31.1% 0.641*   36.3% 22.7% 0.639* I Clindamycin 1.5% 1.9% 0.0%   0.0% 2.3%   2.2% 1.1%   1.3% 4.5% O Erythromycin 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% T Metronidazole 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% I Penicillin 7.3% 5.7% 12.5%   6.5% 6.9%   4.3% 7.8%   3.8% 4.5% C Combination 1.5% 1.0% 3.1%   0.0% 2.3%   0.0% 2.2%   1.3% 0.0% S Other 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% * Chi-squared test, † Fisher’s exact test    33 4.2 Scenario B Same situation as Scenario A except that the patient does report a minor localized swelling.  The results are summarized in Table 5.  Overall, 94.6% of respondents would recommend or prescribe an analgesic in this scenario. No significant differences were found between any of the comparison groups: general dentists vs. endodontists (Fisher’s exact test, p=1.000), <15 vs. >15 years of clinical experience (Fisher’s exact test, p=0.710), female vs. male clinicians (Fisher’s exact test, p=0.414), practice in western half vs. eastern half of Vancouver (Fisher’s exact test, p=0.603).  When considering the specific classification of analgesic, 65.9% of respondents indicated that they would prescribe or recommend a non-opioid analgesic.  27.9% indicated that they would prescribe an opioid analgesic.  No significant differences were found between any of the comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.918), <15 vs. >15 years of clinical experience (Chi-squared test, p=0.731), female vs. male clinicians (Chi-squared test, p=0.491), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.816).  Overall, 73.0% of respondents indicated that they would prescribe an antibiotic in this scenario. No significant differences were found between any of the comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.268), <15 vs. >15 years of clinical experience (Chi-squared test, p=0.358), female vs. male clinicians (Chi-squared test, p=0.294), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.090). When considering the different types of antibiotics, Amoxicillin was most commonly chosen (53.8% of respondents).  This was followed by Penicillin, which was prescribed by   34 14.0% of respondents.  General dentists and endodontists differed in their preferences of antibiotics (Chi-squared test, p=0.002).  60.0% of general dentists indicated that they would prescribe Amoxicillin, compared to 33.3% of endodontists.  8.2% of general dentists indicated that they would prescribe Penicillin, compared to 33.3% of endodontists. No significant differences were found in any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.752), female vs. male clinicians (Chi-squared test, p=0.468), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.518)  35  Table 5 - Results from Scenario B  Overall GD Endo p-value   ≤15 yrs >15 yrs p-value   Female Male p-value   West East p-value A Yes 94.6% 94.7% 94.3% 1.000†   96.3% 93.3% 0.710†   91.8% 95.9% 0.441†   95.4% 91.3% 0.603† N       A No 5.4% 5.3% 5.7%   3.7% 6.7%   8.2% 4.1%   4.6% 8.7% L       G Non-opioids 65.9% 64.9% 68.8% 0.918*   66.0% 65.8% 0.731*   60.0% 69.0% 0.491*   64.9% 63.6% 0.816* E       S Opioids 27.9% 28.9% 25.0%   29.8% 26.6%   31.1% 26.2%   29.7% 27.3% I       C Strong 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% S opioids                                        A Yes 73.0% 75.2% 65.7% 0.268*   68.5% 75.6% 0.358*   67.3% 75.5% 0.294*   78.2% 60.9% 0.090* N       T No 27.0% 24.8% 34.3%   31.5% 24.4%   32.7% 24.5%   21.8% 39.1% I       B Amoxicillin 53.8% 60.0% 33.3% 0.002*   54.0% 55.1% 0.752*   48.9% 56.8% 0.468*   64.3% 52.2% 0.518* I Clindamycin 4.2% 5.5% 0.0%   4.0% 4.5%   6.4% 3.2%   6.0% 4.3% O Erythromycin 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% T Metronidazole 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% I Penicillin 14.0% 8.2% 33.3%   14.0% 12.4%   12.8% 13.7%   7.1% 4.3% C Combination 2.1% 1.8% 3.0%   0.0% 3.4%   0.0% 3.2%   1.2% 0.0% S Other 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% * Chi-squared test, † Fisher’s exact test    36 4.3 Scenario C A patient recently had a deep composite restoration placed 2 weeks ago, but now presents to your office with a severe toothache associated with the same tooth.  The tooth is very painful to percussion.  Once cold is applied to the tooth it becomes painful and this pain lingers for 30 seconds.  A radiograph is taken and there is no evidence of periapical radiolucency.  The tooth is diagnosed as having irreversible pulpitis.  You proceed with root canal treatment on this tooth and complete that treatment on the same day.    The results of the responses are summarized in Table 6.  Overall, 85.6% of respondents would recommend or prescribe an analgesic in this scenario. No significant differences were found between any of the comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.519), <15 vs. >15 years of clinical experience (Chi-squared test, p=0.631), female vs. male clinicians (Chi-squared test, p=0.266), practice in western half vs. eastern half of Vancouver (Fisher’s exact test, p=0.758).  When considering the specific type of analgesic, 81.1% of respondents indicated that they would prescribe or recommend a non-opioid analgesic.  4.5% indicated that they would prescribe an opioid analgesic.  No significant differences were found between any of the comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.795), <15 vs. >15 years of clinical experience (Chi-squared test, p=0.592), female vs. male clinicians (Chi-squared test, p=0.117), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.471).  Overall, 4.8% of respondents indicated that they would prescribe an antibiotic in this scenario.  17.4% of clinicians with dental practices in the eastern half of Vancouver indicated that they would prescribe an antibiotic in this scenario.  This is significantly different than those with practices in the western half of Vancouver, of which 3.6% indicated that they would   37 prescribe an antibiotic (Fisher’s exact test, p=0.037).  No significant differences were found in any of the other comparison groups: general dentists vs. endodontists (Fisher’s exact test, p=0.194), <15 vs. >15 years of clinical experience (Fisher’s exact test, p=0.252), female vs. male clinicians (Fisher’s exact test, p=0.096). When considering the different types of antibiotics, Amoxicillin was most commonly chosen (prescribed by 4.5% of respondents).  This was followed by Clindamycin, which was prescribed by 0.8% of respondents.  Clinicians practicing in the western and eastern halves of Vancouver differed in the types of antibiotics that they would prescribe in this scenario (Chi-squared test, p=0.025).  All of the dentists in the eastern half that indicated they would prescribe antibiotics chose Amoxicillin.  The dentists in the western half that prescribed antibiotics chose either Amoxicillin or Clindamycin.  No significant differences were found in any of the other comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.310), <15 vs. >15 years of clinical experience (Chi-squared test, p=0.475), female vs. male clinicians (Chi-squared test, p=0.158)  38 Table 6 - Results from Scenario C  Overall GD Endo p-value   ≤15 yrs >15 yrs p-value   Female Male p-value   West East p-value A Yes 85.6% 84.5% 88.9% 0.519*   87.0% 84.1% 0.631*   90.0% 83.2% 0.266*   84.5% 82.6% 0.758† N       A No 14.4% 15.5% 11.1%   13.0% 15.9%   10.0% 16.8%   15.5% 17.4% L       G Non-opioids 81.1% 79.8% 84.8% 0.795*   85.1% 78.0% 0.592*   82.6% 80.2% 0.117*   77.9% 85.7% 0.471* E       S Opioids 4.5% 5.1% 3.0%   4.3% 4.9%   8.7% 2.3%   6.5% 0.0% I       C Strong 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% S opioids                                      A Yes 4.8% 6.4% 0.0% 0.194†   1.9% 6.8% 0.252†   0.0% 7.4% 0.096†   3.6% 17.4% 0.037† N       T No 95.2% 93.6% 100%   98.1% 93.2%   100% 92.6%   96.4% 82.6% I       B Amoxicillin 4.5% 5.9% 0.0% 0.310*   2.2% 6.0% 0.475*   0.0% 6.8% 0.158*   2.6% 18.2% 0.025* I Clindamycin 0.8% 1.0% 0.0%   0.0% 1.2%   0.0% 1.1%   1.3% 0.0% O Erythromycin 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% T Metronidazole 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% I Penicillin 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% C Combination 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% S Other 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% * Chi-squared test, † Fisher’s exact test     39 4.4 Scenario D A patient presents as a new patient to your office.  On a radiograph, an asymptomatic tooth is found to be associated with a periapical radiolucency.  The tooth has a deep restoration that approaches the pulp that was completed many years ago.  It does not respond to thermal or electrical pulp testing, and the tooth is diagnosed as necrotic. You proceed with root canal treatment on this tooth and complete that treatment on the same day.    The results are summarized in Table 7.  Overall, 67.6% of respondents would recommend or prescribe an analgesic in this scenario.  80.4% of female clinicians indicated that they would recommend or prescribe an analgesic.  This is significantly higher than male clinicians, of which 60.4% said they would do so (Chi-squared test, p=0.014).  No significant differences were found in any of the other comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.782), <15 vs. >15 years of clinical experience (Chi-squared test, p=0.154), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.277).  When considering the specific type of analgesic, 63.0% of respondents indicated that they would prescribe or recommend a non-opioid analgesic.  3.6% indicated that they would prescribe an opioid analgesic.  76.1% of female clinicians indicated that they would recommend or prescribe a non-opioid analgesic, compared to 56.0% of male clinicians.  4.3% of female clinicians indicated that they would prescribe an opioid analgesic, compared to 3.3% of male clinicians.  These differences were found to be significantly different (Chi-squared test, p=0.047).  No significant differences were found in any of the other comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.436), <15 vs. >15 years of clinical experience (Chi-squared test, p=0.139), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.375).    40 Overall, 30.1% of respondents indicated that they would prescribe an antibiotic in this scenario.  36.9% of general dentists indicated that they would prescribe an antibiotic, compared to 8.6% of endodontists.  This was found to be a significant difference (Chi-squared test, p=0.001).  No significant differences were found between any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.157), female vs. male clinicians (Chi-squared test, p=0.769), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.801). When considering the different types of antibiotics, Amoxicillin was most commonly chosen (prescribed by 22.8% of respondents).  This was followed by Penicillin and Clindamycin, which were each prescribed by 4.4% of respondents.  General dentists and endodontists differed in the types of antibiotics that they would prescribe in this scenario (Chi-squared test, p=0.041).  There was also a significant difference in the responses of female clinicians and male clinicians (Chi-squared test, p=0.008).  No significant differences were found in any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.646), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.986).    41 Table 7 - Results from Scenario D  Overall GD Endo p-value   ≤15 yrs >15 yrs p-value   Female Male p-value   West East p-value A Yes 67.6% 67.0% 69.4% 0.782*   75.0% 63.6% 0.154*   80.4% 60.4% 0.014*   68.6% 56.5% 0.277* N       A No 32.4% 33.0% 30.6%   25.0% 36.4%   19.6% 39.6%   31.4% 43.5% L       G Non-opioids 63.0% 61.9% 66.7% 0.436*   74.0% 57.1% 0.139*   76.1% 56.0% 0.047*   62.2% 57.1% 0.375* E       S Opioids 3.6% 4.8% 0.0%   2.0% 4.8%   4.3% 3.3%   6.1% 0.0% I       C Strong 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% S opioids                                      A Yes 30.1% 36.9% 8.6% 0.001*   23.6% 34.9% 0.157*   28.2% 31.2% 0.769*   37.6% 34.8% 0.801* N       T No 69.9% 63.1% 91.4%   76.4% 65.1%   71.2% 68.8%   62.4% 65.2% I       B Amoxicillin 22.8% 27.6% 6.5% 0.041*   17.0% 26.2% 0.646*   14.6% 27.6% 0.008*   28.8% 27.3% 0.986* I Clindamycin 4.4% 5.7% 0.0%   6.4% 3.6%   12.5% 0.0%   6.3% 4.5% O Erythromycin 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% T Metronidazole 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% I Penicillin 4.4% 4.8% 3.2%   4.3% 4.8%   4.2% 4.6%   5.0% 4.5% C Combination 0.7% 1.0% 0.0%   0.0% 1.2%   0.0% 1.1%   0.0% 0.0% S Other 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% * Chi-squared test, † Fisher’s exact test     42 4.5 Scenario E A patient presents to your office with a severe toothache associated with a localized swelling.  The tooth nearest the swelling does not respond to thermal or electrical pulp testing.  This tooth is diagnosed as necrotic with an acute apical abscess.  Radiographically, a large periapical radiolucency is present. You initiate root canal treatment that same day.  You fully instrument all of the canals, obtaining some drainage through the canals, and will bring the patient back at another time to complete root canal treatment.  The results are summarized in Table 8.  Overall, 92.5% of respondents would recommend or prescribe an analgesic in this scenario. No significant differences were found in any of the comparison groups: general dentists vs. endodontists (Fisher’s exact test, p=0.140), <15 vs. >15 years of clinical experience (Fisher’s exact test, p=0.526), female vs. male clinicians (Fisher’s exact test, p=0.747), practice in western half vs. eastern half of Vancouver (Fisher’s exact test, p=0.100).  When considering the specific type of analgesic, 70.8% of respondents indicated that they would prescribe or recommend a non-opioid analgesic.  21.5% indicated that they would prescribe an opioid analgesic.  69.4% of general dentists indicated that they would recommend or prescribe a non-opioid analgesic, compared to 75.0% of endodontists.  25.5% of general dentists indicated that they would prescribe an opioid analgesic, compared to 9.4% of endodontists.  This was found to be significantly different (Chi-squared test, p=0.039).  No significant differences were found in any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.296), female vs. male clinicians (Chi-squared test, p=0.482), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.337).    43 Overall, 66.9% of respondents indicated that they would prescribe an antibiotic in this scenario.  77.9% of general dentists indicated that they would prescribe an antibiotic, compared to 31.4% of endodontists.  This was found to be a significant difference (Chi-squared test, p<0.001).  73.6% of clinicians with >15 years of clinical experience indicated that they would prescribe an antibiotic, compared to 53.6% of clinicians with <15 years of clinical experience.  This was also significantly different (Chi-squared test, p=0.014).  No significant differences were found between any of the other comparison groups: female vs. male clinicians (Chi-squared test, p=1.000), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.492). When considering the different types of antibiotics, Amoxicillin was most commonly chosen (prescribed by 49.7% of respondents).  This was followed by Penicillin, which was prescribed by 9.8% of respondents.  General dentists and endodontists differed in the types of antibiotics that they would prescribe in this scenario (Chi-squared test, p<0.001). 58.0% of general dentists indicated that they would prescribe Amoxicillin, compared to 19.4% of endodontists.  8.9% of general dentists indicated that they would prescribe Penicillin, compared to 12.9% of endodontists.  8.0% of general dentists indicated that they would prescribe Clindamycin, compared to 0.0% of endodontists.  No significant differences were found in any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.452), female vs. male clinicians (Chi-squared test, p=0.417), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.749).  44 Table 8 - Results from Scenario E  Overall GD Endo p-value   ≤15 yrs >15 yrs p-value   Female Male p-value   West East p-value A Yes 92.5% 94.5% 86.1% 0.140†   94.6% 90.6% 0.526†   94.1% 91.5% 0.747†   96.5% 86.4% 0.100† N       A No 7.5% 5.5% 13.9%   5.4% 9.4%   5.9% 8.5%   3.5% 13.6% L       G Non-opioids 70.8% 69.4% 75.0% 0.039*   78.7% 66.7% 0.296*   77.3% 68.2% 0.482*   72.7% 57.9% 0.337* E       S Opioids 21.5% 25.5% 9.4%   17.0% 23.1%   18.2% 22.4%   23.4% 31.6% I       C Strong 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% S opioids                                      A Yes 66.9% 77.9% 31.4% <0.001*   53.6% 73.6% 0.014*   66.7% 66.7% 1.000*   75.9% 82.6% 0.492* N       T No 33.1% 22.1% 68.6%   46.4% 26.4%   33.3% 33.3%   24.1% 17.4% I       B Amoxicillin 49.7% 58.0% 19.4% <0.001*   42.3% 53.5% 0.452*   50.0% 50.0% 0.417*   57.0% 69.6% 0.749* I Clindamycin 6.3% 8.0% 0.0%   5.8% 7.0%   10.0% 4.3%   8.1% 8.7% O Erythromycin 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% T Metronidazole 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% I Penicillin 9.8% 8.9% 12.9%   7.7% 9.3%   8.0% 9.8%   8.1% 4.3% C Combination 2.8% 3.6% 0.0%   1.9% 3.5%   0.0% 4.3%   3.5% 0.0% S Other 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% * Chi-squared test, † Fisher’s exact test   45 4.6 Scenario F You recently saw a patient and completed root canal treatment on a tooth.  After 3 days, the patient returns in severe pain with a visible swelling in the gingival area of the tooth that was treated.  Your final radiograph shows no obvious deficiencies in the root canal filling.  The results are summarized in Table 9.  Overall, 99.3% of respondents would recommend or prescribe an analgesic in this scenario. No significant differences were found in any of the comparison groups: general dentists vs. endodontists (Fisher’s exact test, p=1.000), <15 vs. >15 years of clinical experience (Fisher’s exact test, p=1.000), female vs. male clinicians (Fisher’s exact test, p=1.000), practice in western half vs. eastern half of Vancouver (Fisher’s exact test, p=0.213).  When considering the specific type of analgesic, 64.6% of respondents indicated that they would prescribe or recommend a non-opioid analgesic.  33.9% indicated that they would prescribe an opioid analgesic. No significant differences were found in any of the comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.071), <15 vs. >15 years of clinical experience (Chi-squared test, p=0.697), female vs. male clinicians (Chi-squared test, p=0.688), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.153).  Overall, 88.4% of respondents indicated that they would prescribe an antibiotic in this scenario.  91.9% of general dentists indicated that they would prescribe an antibiotic, compared to 77.1% of endodontists.  This was found to be a significant difference (Fisher’s exact test, p=0.031).  No significant differences were found between any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.509), female vs. male clinicians   46 (Chi-squared test, p=0.555), practice in western half vs. eastern half of Vancouver (Fisher’s exact test, p=0.153). When considering the different types of antibiotics, Amoxicillin was most commonly chosen (prescribed by 60.4% of respondents).  This was followed by Penicillin, which was prescribed by 13.9% of respondents.  General dentists and endodontists differed in the types of antibiotics that they would prescribe in this scenario (Chi-squared test, p=0.029). 64.2% of general dentists indicated that they would prescribe Amoxicillin, compared to 48.6% of endodontists.  11.0% of general dentists indicated that they would prescribe Penicillin, compared to 22.9% of endodontists.  11.0% of general dentists indicated that they would prescribe Clindamycin, compared to 0.0% of endodontists.  No significant differences were found in any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.527), female vs. male clinicians (Chi-squared test, p=0.181), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.151).     47 Table 9 - Results from Scenario F  Overall GD Endo p-value   ≤15 yrs >15 yrs p-value   Female Male p-value   West East p-value A Yes 99.3% 99.1% 100% 1.000†   100% 98.8% 1.000†   100% 98.9% 1.000†   100% 95.7% 0.213† N       A No 0.7% 0.9% 0.0%   0.0% 1.2%   0.0% 1.1%   0.0% 4.3% L       G Non-opioids 64.6% 60.4% 77.4% 0.071*   63.8% 65.8% 0.697*   62.2% 65.9% 0.688*   59.5% 61.9% 0.153* E       S Opioids 33.9% 38.5% 19.4%   36.2% 31.6%   37.8% 31.7%   40.5% 33.3% I       C Strong 0.8% 0.0% 3.2%   0.0% 1.3%   0.0% 1.2%   0.0% 0.0% S opioids                                      A Yes 88.4% 91.9% 77.1% 0.031†   85.7% 89.4% 0.509*   90.4% 87.1% 0.555*   91.8% 91.3% 1.000† N         T No 11.6% 8.1% 22.9%   14.3% 10.6%   9.6% 12.9%   8.2% 8.7% I         B Amoxicillin 60.4% 64.2% 48.6% 0.029*   53.7% 65.9% 0.527*   57.7% 62.6% 0.181*   65.1% 69.6% 0.151* I Clindamycin 8.3% 11.0% 0.0%   7.4% 8.2%   15.4% 4.4%   12.0% 8.7% O Erythromycin 0.0% 0.0% 0.0%   0.0% 0.0%   0.0% 0.0%   0.0% 0.0% T Metronidazole 0.7% 0.9% 0.0%   1.9% 0.0%   0.0% 1.1%   0.0% 4.3% I Penicillin 13.9% 11.0% 22.9%   16.7% 10.6%   13.5% 13.2%   10.8% 4.3% C Combination 4.9% 4.6% 5.7%   5.6% 4.7%   1.9% 6.6%   4.8% 0.0% S Other 0.7% 0.9% 0.0%   1.9% 0.0%   1.9% 0.0%   0.0% 4.3% * Chi-squared test, † Fisher’s exact test   48 4.7 Scenario G The same patient in Scenario F returns again 2 days later and the pain is unbearable and the swelling has progressed significantly.  The skin overlying the area of the treated tooth is red and warm.  The results are summarized in Table 10.  Overall, 65.8% of respondents would change the analgesic that they had originally recommended or prescribed in Scenario F.  No significant differences were found in any of the comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.411), <15 vs. >15 years of clinical experience (Chi-squared test, p=0.792), female vs. male clinicians (Chi-squared test, p=0.980), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.903).  When considering the specific type of analgesic they would recommend or prescribe, 15.6% of respondents indicated that they would now recommend or prescribe a non-opioid analgesic.  32.0% indicated that they would now prescribe an opioid analgesic.  14.8% of respondents indicated that they would now prescribe a strong opioid.  General dentists and endodontists differed in the types of analgesics that they would now recommend or prescribe in this scenario (Chi-squared test, p=0.021).  15.6% of general dentists indicated non-opioid analgesics, as compared to 31.0% of endodontists.  37.4% of general dentists indicated opioids, compared to 13.8% of endodontists.  15.2% of general dentists indicated strong opioids, compared to 13.8% of endodontists.  No significant differences were found in any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.452), female vs. male clinicians (Chi-squared test, p=0.935), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.291).    49 Overall, 75.7% of respondents would change the antibiotic that they had originally recommended or prescribed in Scenario F.  87.3% of clinicians with <15 years of clinical experience would change the antibiotic, as compared to 67.9% of those with >15 years of clinical experience.  This was found to be a significant difference (Chi-squared test, p=0.009).  No significant differences were found between any of the other comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.563), female vs. male clinicians (Chi-squared test, p=0.485), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.280). When considering the different types of antibiotics, 33.1% of respondents indicated that they would now prescribe Clindamycin.  18.3% indicated that they would prescribe a combination of antibiotics.  13.4% indicated that they would now prescribe Metronidazole.   No significant differences were found in any of the comparison groups: general dentists vs. endodontists (Chi-squared test, p=0.080), <15 vs. >15 years of clinical experience (Chi-squared test, p=0.185), female vs. male clinicians (Chi-squared test, p=0.242), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.263).    50 Table 10 - Results from Scenario G  Overall GD Endo p-value   ≤15 yrs >15 yrs p-value   Female Male p-value   West East p-value A Yes 65.8% 67.6% 60.0% 0.411*   67.3% 65.1% 0.792*   65.4% 65.6% 0.980*   68.2% 69.6% 0.903* N       A No 34.2% 32.4% 40.0%   32.7% 34.9%   34.6% 34.4%   31.8% 30.4% L       G Non-opioids 15.6% 11.1% 31.0% 0.021*   20.8% 10.7% 0.452*   18.2% 14.5% 0.935*   12.0% 9.5% 0.291* E       S Opioids 32.0% 37.4% 13.8%   31.3% 33.3%   29.5% 32.5%   33.3% 52.4% I       C Strong 14.8% 15.2% 13.8%   12.5% 17.3%   13.6% 15.7%   18.7% 4.8% S opioids                                      A Yes 75.7% 74.5% 79.4% 0.563*   87.3% 67.9% 0.009*   78.8% 73.6% 0.485*   71.4% 82.6% 0.280* N       T No 24.3% 25.5% 20.6%   12.7% 32.1%   21.2% 26.4%   28.6% 17.4% I       B Amoxicillin 4.2% 4.5% 3.1% 0.080*   5.6% 3.6% 0.185*   3.9% 4.4% 0.242*   4.8% 4.3% 0.263* I Clindamycin 33.1% 32.7% 34.4%   35.2% 28.9%   31.4% 33.3%   28.6% 39.1% O Erythromycin 0.7% 0.9% 0.0%   0.0% 1.2%   0.0% 1.1%   0.0% 4.3% T Metronidazole 13.4% 14.5% 9.4%   18.5% 10.8%   19.6% 10.0%   17.9% 4.3% I Penicillin 4.9% 1.8% 15.6%   3.7% 6.0%   3.9% 5.6%   1.2% 4.3% C Combination 18.3% 17.3% 21.9%   24.1% 15.7%   15.7% 20.0%   16.7% 21.7% S Other 2.1% 2.7% 0.0%   1.9% 2.4%   5.9% 0.0%   2.4% 4.3% * Chi-squared test, † Fisher’s exact test    51 4.8 Comparisons between general dentists and endodontists in the various clinical scenarios Figures 5 and 6 summarize the responses from general dentists and endodontists with regards to the various clinical scenarios.  Figure 5 compares the prescription of opioid analgesics (including opioids and strong opioids), while Figure 6 compares the prescription of antibiotics.    Figure 5 - Comparison of opioid prescription between general dentists and endodontists in the various clinical scenarios   * indicates a statistically significant difference with either Chi-squared or Fisher’s exact test (Scenarios E and G)    0%20%40%60%80%100%A B C D E * F G *Percentage that would prescribe an opioid analgesicScenarioGeneral dentists Endodontists  52 Figure 6 - Comparison of antibiotic prescription between general dentists and endodontists in the various clinical scenarios  * indicates a statistically significant difference with either Chi-squared or Fisher’s exact test (Scenarios D, E, and F)  4.9 Diagnosis-based antibiotic prescription The results from the diagnosis-based table in the survey are summarized in Table 11 and will now be described.   For irreversible pulpitis with no or mild symptoms, 0.0% of respondents would prescribe an antibiotic.  For irreversible pulpitis with moderate or severe symptoms, 20.3% of respondents would prescribe an antibiotic.  More general dentists indicated that they would prescribe antibiotics than endodontists (25.9% vs. 2.8%, Chi-squared test, p=0.003).  No significant differences were 0%20%40%60%80%100%A B C D * E * F * GPercentage that would prescribe an antibioticScenarioGeneral dentists Endodontists  53 found in any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.153), female vs. male clinicians (Chi-squared test, p=0.494), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.126).  For pulp necrosis with no swelling and no or mild symptoms, 14.9% of respondents would prescribe an antibiotic.  More general dentists indicated that they would prescribe antibiotics than endodontists (18.8% vs. 2.8%, Chi-squared test, p=0.019).  No significant differences were found in any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.443), female vs. male clinicians (Chi-squared test, p=0.759), practice in western half vs. eastern half of Vancouver (Fisher’s exact test, p=1.000). For pulp necrosis with no swelling and moderate or severe symptoms, 49.3% of respondents would prescribe an antibiotic.  More general dentists indicated that they would prescribe antibiotics than endodontists (59.1% vs. 19.4%, Chi-squared test, p<0.001).  More clinicians working in the eastern half of Vancouver indicated that they would prescribe an antibiotic than those working on the western half (81.8% vs. 51.8%, Chi-squared test, p=0.011). No significant differences were found in any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.105), female vs. male clinicians (Chi-squared test, p=0.992). For pulp necrosis with a sinus tract and no or mild symptoms, 35.8% of respondents would prescribe an antibiotic.  More general dentists indicated that they would prescribe antibiotics than endodontists (45.5% vs. 5.6%, Chi-squared test, p<0.001).  No significant differences were found in any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.627), female vs. male clinicians (Chi-squared test, p=0.222), practice in western half vs. eastern half of Vancouver (Chi-squared test, p=0.527).   54 For pulp necrosis with a swelling, and moderate or severe symptoms, 90.5% of respondents would prescribe an antibiotic.  More general dentists indicated that they would prescribe antibiotics than endodontists (96.4% vs. 72.2%, Fisher’s exact test, p<0.001).  No significant differences were found in any of the other comparison groups: <15 vs. >15 years of clinical experience (Chi-squared test, p=0.382), female vs. male clinicians (Fisher’s exact test, p=0.381), practice in western half vs. eastern half of Vancouver (Fisher’s exact test, p=1.000). The responses of general dentists and endodontists are summarized in Figure 7.  55 Table 11 – Antibiotic prescription results from the diagnosis-based table  Overall GD Endo p-value   ≤15 yrs >15 yrs p-value   Female Male p-value    West East p-value Irreversible pulpitis; no/mild symptoms                                 0% 0% 0% 1.000†   0% 0% 1.000†   0% 0% 1.000†   0% 0% 1.000†                                Irreversible pulpitis; mod./sev. symptoms                                 20.3% 25.9% 2.8% 0.003*   14.3% 24.1% 0.153*   23.5% 18.8% 0.494*   23.3% 39.1% 0.126*                                  Pulp necrosis; no swelling; no/mild symptoms                                 14.9% 18.8% 2.8% 0.019*   12.5% 17.2% 0.443*   13.7% 15.6% 0.759*   18.6% 17.4% 1.000†                                 Pulp necrosis; no swelling; mod./sev. symptoms                                 49.3% 59.1% 19.4% <0.001*   41.8% 55.8% 0.105*   49.0% 48.9% 0.992*   51.8% 81.8% 0.011*                                  Pulp necrosis; sinus tract; no/mild symptoms                                35.8% 45.5% 5.6% <0.001*   33.9% 37.9% 0.627*   29.4% 39.6% 0.222*   46.5% 39.1% 0.527*                                  Pulp necrosis; swelling; mod./sev. symptoms                                 90.5% 96.4% 72.2% <0.001†   87.5% 92.0% 0.382*   94.1% 88.5% 0.381†   96.5% 95.7% 1.000†                                 * Chi-squared test, † Fisher’s exact test   56 Figure 7 - Comparison of antibiotic prescription between general dentists and endodontists in the various diagnoses presented in the table  * indicates a statistically significant difference  The results from the diagnosis-based table in our survey were compared to the results published by Whitten in 1996 (62) (Table 12).  Significantly less respondents indicated that they would prescribe an antibiotic in our survey when compared to the 1996 survey; this was true for all of the diagnoses included in the table. This was true when the endodontists in our survey were 0%20%40%60%80%100%Irr. pulpitis; no/mild sympIrr. pulpitis; mod/sev symp *Necrosis; no/mild symp *Necrosis; no swelling; mod/sev symp *Necrosis; sinus tract; no/mild symp *Necrosis; swelling; mod/sev symp *Percentage that would prescribe an antibioticDiagnosisGeneral dentistsEndodontists  57 compared to the endodontists in the 1996 survey, and when the general dentists in our survey were compared to the general dentists in the 1996 survey.  A summary of the comparison of the overall responses is shown in Figure 8.  Table 12 - Comparison of antibiotic prescription from 1996 (n=651) and 2013 (n=152) studies   1996 2013 p-value Irreversible pulpitis; no/mild symptoms Overall 16.7% 0% <0.001† General dentists 23.2% 0% <0.001† Endodontists 9.3% 0% 0.056† Irreversible pulpitis; moderate/severe symptoms Overall 39.5% 20.3% <0.001* General dentists 51.8% 25.9% <0.001* Endodontists 25.4% 2.8% <0.001†  Pulp necrosis; no swelling; no/mild symptoms Overall 35.4% 14.9% <0.001* General dentists 35.1% 18.8% 0.001* Endodontists 35.7% 2.8% <0.001†  Pulp necrosis; no swelling; moderate/severe symptoms Overall 64.3% 49.3% <0.001* General dentists 61.6% 59.1% 0.628* Endodontists 67.3% 19.4% <0.001*  Pulp necrosis; sinus tract; no/mild symptoms Overall 47.0% 35.8% 0.014* General dentists 62.5% 45.5% 0.002* Endodontists 29.2% 5.6% <0.001†  Pulp necrosis; swelling; moderate/severe symptoms Overall 95.7% 90.5% 0.011* General dentists 94.9% 96.4% 0.531* Endodontists 96.6% 72.2% 0.001* * Chi-squared test, † Fisher’s exact test          58  Figure 8 - Comparison of antibiotic prescription between 1996 and 2013 studies  * indicates a statistically significant difference  0%20%40%60%80%100%Irr. pulpitis; no/mild symp *Irr. pulpitis; mod/sev symp *Necrosis; no/mild symp *Necrosis; no swelling; mod/sev symp *Necrosis; sinus tract; no/mild symp *Necrosis; swelling; mod/sev symp *Percentage that would prescribe an antibioticDiagnosis19962013  59 Chapter 5: Discussion  5.1 Analgesics In the introduction, the prescription of analgesics in endodontics was discussed.  In general, endodontic treatment is a very effective way of treating pain originating from pulpal and periapical disease (44).  However, as post-treatment pain is not uncommon, the prescription or recommendation of analgesics following endodontic treatment may be warranted.  According to expert opinion, the use of NSAIDs, or acetaminophen if NSAIDs are contraindicated, should be maximized prior to incorporating any opioid analgesics into the pain management strategy (45).  This is both due to the effectiveness of NSAIDs and the problems associated with the overuse of opioids.  Only when the pain is severe and not appropriately managed with non-narcotics should opioids be prescribed.   When using this information to assess the clinical scenarios in our survey, I feel that Scenario G was the only scenario where it would be appropriate to prescribe an opioid analgesic.  Scenario G was a situation where pain following endodontic treatment had not been appropriately managed by initial clinical and pharmacological treatment.  This pain in fact had gotten worse.  According to Keiser et al. (45), as long as the use of non-narcotics has been maximized, one may prescribe an opioid analgesic to attempt to reduce this pain. I feel that the prescription of opioid analgesics is inappropriate in the other six scenarios.  A significant proportion of the respondents to our survey indicated that they would prescribe opioid analgesics in these scenarios.  This was more evident in cases where a patient telephoned the office in an emergency-type situation, or when the patient presented with a visible swelling.  This is quite concerning, knowing the potential for abuse of these medications.  I believe dentists   60 need to be more wary when prescribing these medications.  Perhaps educating dental professionals about the extent of non-prescription opioid use in Canada and about the problems associated with opioid dependency and addiction may help alter their decisions with regards to prescribing these medications.           When comparing the decisions of general dentists to endodontists, an overall trend was noticed.  Although not supported by statistical analysis, general dentists prescribed opioid analgesics more often than endodontists in all of the scenarios.  However, as statistically significant differences were found in only two of the scenarios, no concrete conclusions can be drawn on the differences in prescription decisions between general dentists and endodontists with regards to opioid analgesics.   There may be a number of reasons why endodontists prescribe these medications less often than general dentists.  Perhaps they are more comfortable knowing that the endodontic treatment they provide will alleviate the patient’s pain.  Perhaps they are more comfortable recommending medications that do not require a prescription, such as ibuprofen, to someone in pain.  Perhaps they are more knowledgeable about the effectiveness of NSAIDs and acetaminophen.  Whatever the reasons are, I believe it should be a goal of all endodontists to help better inform the general dentists with whom they work with.    The comparisons between the other groups with regards to the types of analgesics prescribed resulted in only minor, inconsistent differences.  In addition, no trends were seen as in the case of the comparison of endodontists to general dentists.  It was concluded that there were no differences in opioid analgesic prescription decisions between clinicians of different gender, clinical experience, or practice location.  This was a very positive finding and suggests consistency throughout the profession.      61   5.2 Antibiotics  In the introduction it was explained that the indication for the use of antibiotics in endodontics is limited.  Antibiotics are not indicated in cases of irreversible pulpitis or in cases where a swelling is small or localized (57).  Antibiotics should only be used when it appears that an infection is spreading or if signs of systemic involvement are present (60).  This expert opinion has been repeated in the literature and also has the support of the Canadian Academy of Endodontics (66) and the American Association of Endodontists (67).   In our survey, Scenario G was a situation where it seemed that the infection was spreading and the skin overlying the infection had become warm.  I believe it was the only scenario in which antibiotics were clearly indicated.  Another scenario that may warrant the prescription of antibiotics was Scenario B.  In this scenario, a patient telephoned a dentist with a toothache and indicated that a localized swelling was present.  As they were unable to immediately come in for endodontic treatment, some may argue that prescribing an antibiotic would prevent a more severe infection from arising.  However, others may argue that antibiotics are not indicated as the swelling is localized and antibiotics are not curative.   On a related note, research on patients that underwent oral surgery showed that the patients’ reports of swelling were fairly accurate (68).  However, the presence and size of a swelling is subjective and influenced by the presence of pain.  It can be argued that the accuracy of the patient’s report of a swelling being present could be questionable.  It has been shown that even clinical exams by dentists may be inaccurate in detecting swellings (69).  The remaining five scenarios were all situations where antibiotics were not indicated.  Some of these scenarios described situations where a swelling was not present.  Another scenario   62 included a swelling that had been drained.  Another scenario involved a localized swelling that needed to be drained.  The results indicated that substantial proportion of respondents would prescribe antibiotics in these situations.  The decision to prescribe antibiotics was made more often than the decision to prescribe opioid analgesics.  It is my belief that clinicians believe that they are doing no harm by writing a prescription for antibiotics.  I feel that some clinicians may worry that their patients may feel neglected if an antibiotic is not prescribed when in pain; others may fear future litigation if the problem worsens.  In fact, such clinicians are contributing to the global problem of bacterial resistance to antibiotics.             General dentists prescribed antibiotics more often than endodontists.  Significant differences were found with Scenarios D, E, and F.  However, no statistical differences were found between the groups in the other four scenarios.  As with opioid analgesics, no concrete overall conclusion could be drawn from these results.  Again, a trend was noticed where general dentists prescribed antibiotics more frequently than endodontists.     The comparisons between the other groups with regards to antibiotic prescription resulted in only minor, inconsistent differences.  In addition, no trends were seen as in the case of the comparison of endodontists to general dentists.  It was concluded that there were no differences in opioid analgesic prescription decisions between clinicians of different gender, clinical experience, or practice location.  These findings were consistent with the results found with opioid analgesic prescription.    An interesting trend was found when analyzing the specific type of antibiotic that was being prescribed in the different scenarios.  In six out of the seven scenarios, Amoxicillin was the most commonly prescribed antibiotic.  Penicillin was the second most commonly prescribed antibiotic.  In four of the scenarios (B, D, E, and F), statistically significant differences were   63 found between general dentists and endodontists.  It appeared that endodontists were more likely to prescribe Penicillin than general dentists.  It is difficult to speculate as to why this is the case.  On may suggest that the practitioners differed as a result of when they attended dental school.  However, no such trends were seen when comparing the results based on years of clinical experience.    The diagnosis-based table included in the survey was identical to a table used by Whitten et al. to explore antibiotic prescription in the U.S. in the 1990s (62).  Its inclusion in our survey provided useful information.  It allowed us to compare the prescription decisions of the different groups using a different approach than clinical scenarios.  It also allowed us to compare the results from our survey in 2013, which included general dentists in Vancouver and endodontists in British Columbia, to their survey in 1996, which included general dentists and endodontists in the U.S.   Of all the diagnoses listed in the table, I believe that only the last one could arguably warrant the prescription of antibiotics.  The other diagnoses were of teeth with irreversible pulpitis or necrosis with no swelling.  In the last diagnosis, the description was of necrosis with a swelling accompanied by moderate to severe pain.  There was no clinical description of the swelling, and whether or not it appeared to be spreading.  As a result, one can argue that antibiotic prescription would be appropriate in this case.  90.5% of respondents indicated that they would prescribe antibiotics in cases with this diagnosis.  However, as endodontic treatment had been initiated, the argument against the prescription of antibiotics in this case could also be supported.    64 In the first five diagnoses, antibiotics would be prescribed by 0%, 20.3%, 14.9%, 49.3%, and 35.8% of respondents (in the order that they were listed in the table).  I believe these clinicians would be inappropriately prescribing these medications, for reasons explained earlier.   When comparing the different groups, statistically significant differences were found between general dentists and endodontists in all cases.  As with the clinical scenarios, a higher percentage of general dentists inappropriately prescribed antibiotics.  This may be a result of endodontists having more education on the topic and being more comfortable not prescribing antibiotics in these scenarios.  However, it may also be a result of the nature of dental practice in today’s society.  General dentists aim to retain their patients, and perhaps the fear of a patient getting upset and leaving their practice influences their decision.  An endodontist does not have that same pressure on their decision-making.  When the other groups were compared, no differences were seen with regards to years of clinical experiences, gender, or practice location (the only exception was with one case where higher percentage of those working on the eastern half of Vancouver would prescribe an antibiotic). When comparing the results of our survey to that of Whitten et al., significant differences were found in all of the cases. With our results, a significantly lower percentage of respondents indicated that they would prescribe antibiotics in all of the cases.  More specifically, a significantly lower percentage of endodontists indicated that they would prescribe antibiotics in all of the cases, and a significantly lower percentage of general dentists indicated that they would prescribe antibiotics in four out of the six cases.  This is a comforting finding.  This could mean that the decisions are improving.  Alternatively, it could also mean that Canadian dentists are making better decisions than American dentists.  However, these are just possibilities and definitely would need to be explored further to be supported.     65 In summary, a significant proportion of the respondents to our survey would inappropriately prescribe antibiotics.  General dentists reported prescribing antibiotics more often than endodontists.  No conclusive differences were found between the other comparison groups.  However, the respondents to our survey reported prescribing antibiotics less frequently than the respondents of a 1996 U.S. survey.  5.3 Response rates and potential biases of the survey Surveys are tools commonly used in research that can be very useful.  Sound conclusions can be drawn from surveys as long as they are precise and unbiased (70).   Imprecision usually results from including too small a percentage of the overall population in the sample (70).  This can be avoided or minimized by making a sample as large as feasibly possible.  The populations of interest in this study were general dentists in the city of Vancouver and endodontists in the province of British Columbia.  Half of the general dentists in Vancouver and all of the endodontists in British Columbia were included in the sample.  This resulted in an original sample size of 284 general dentists and 51 endodontists.  One can argue that more general dentists could have been included in the survey to improve the precision.  However, this may have affected the survey in a detrimental manner.  With the current sample size it was possible to follow-up with all of the offices a number of times, and this resulted in a relatively high response rate.  By increasing the sample size, it may not have been possible to follow up as succinctly, and the response rate may have been lower. One type of bias can arise from the selection of the sample, and it can be avoided by randomly selecting the sample (70).  In this study, all of the endodontists in British Columbia   66 were included in the sample; no selection was necessary.  The sample of general dentists was selected at random; therefore, there was no bias present from the selection of the sample. Another type of bias that may be present during a survey research is non-response bias.  In this study, 49.2% of the sample responded with completed surveys.  That means that 50.8% of practitioners didn’t respond.  One can only assume that the people that responded are representative of the overall cohort of practitioners, and this is where non-response bias may occur (71).  One way of eliminating the non-response bias is to increase the response rates (72).  Studies have shown that there are a few specific ways that response rates can be increased (73,74).  One is to make the survey easy to complete and return, and another is to follow-up a number of times.  However, if non-responsiveness persists, it has been shown that following up more than three times does not seem to increase response rates significantly (74). In the present study, multiple efforts were used to increase response rates.  It did take significant effort to achieve a final response rate of 49.2%.  Firstly, we developed the survey with the intentions of making it easy to understand and complete.  Secondly, we then completed a pilot study, which was a crucial step in the final design of the survey (75).  Additionally, we tried to make it as easy as possible for the clinicians to participate in the study. We sent the surveys by either fax, email or mail.  We offered the same methods for the return of the completed survey at no cost to the clinician.  After the first distribution by email or fax, the response rate was approximately 22.0%.  Each of the offices of the non-responding individuals were contacted and reminded about the survey.  After a second distribution of the survey, the response rate increased to approximately 32.0%.  For a third and final distribution, the surveys were mailed with pre-stamped return envelope.  This resulted in the final response rate increasing to 49.2%.   67 In the past, some have tried to assess the non-response bias in their studies by either interviewing non-responders (76) or comparing demographical data between the responders and non-responders (77,78) to see if the apparent selection may occur.  In the present study, aspects such as age, gender, or practice location status have been analyzed to see if there will be differences between the responders and non-responders.  The only difference seen was that proportionally more of the respondents were from the western half of Vancouver.  It is difficult to speculate the reasoning for this.  Regardless of the reason, it must be stated that based on this information some non-response could contribute to bias. Given there were no substantial differences in findings between the dentists from the western part of Vancouver and those from the eastern part of Vancouver, we presume that this bias is minimal and that the present findings are representative of all Vancouver dental professionals. During the course of the research, it was evident that the greatest difficulty was ensuring that the dentist actually received the survey.  Universally, it was through a receptionist that the correspondence was being transferred to the dentist.  During our phone conversations, some office receptionists indicated that they did not receive the survey, while others indicated that they forgot to give the survey to the dentist.  That is more support for why it is important to follow-up a number of times with non-respondents and to correspond by a method that was easiest for the office.    When deciding whether or not a response rate was adequate, we compared ours to other surveys on the topic.  Commonly cited surveys in endodontic literature had response rates of 42.9% (54), 55.3% (55), 43.4% (62), and 50.1% (63).   It can be concluded that the response rate of 49.2% in this study is comparable to other studies.  Of interest, 42.8% of general dentists responded compared to 72.0% of endodontists.  An association has been made between response   68 rates of different populations and their willingness to participate in research (79).  A population’s interest on the subject matter also influences how likely they are to respond (79).  It can be speculated that a greater proportion of endodontists responded to the survey because they are more interested on the subject of the survey; consequently, they are more likely to want to participate in research focused on endodontics.  5.4 Novelty of the present research  Descriptive clinical scenarios have not been used in past research to evaluate the appropriate prescription of opioid analgesics and antibiotics by dentists or endodontists.  In the past, specific diagnoses have been used to form the framework of surveys (54,62,63).  The specific scenarios in this study were chosen for a number of reasons.  First, they cover a wide range of situations that may arise in endodontics.  Scenarios A and B described situations where a patient was in pain but they could not immediately come to the dental office for endodontic treatment.  Scenarios C, D, and E were situations where routine endodontic treatment was performed for patients with various stages of pulpal and periapical disease.  Scenarios F and G were situations where pain arose after endodontic treatment was performed.  Second, it was felt that a clinician would be able to envision the situation more clearly by using a clinical scenario than providing only a clinical diagnosis.  As a result, they may more accurately report what decisions they would make in such situations.  5.5 Significance, future directions, limitations From this survey, it seemed that a significant proportion of general dentists in Vancouver and endodontists in British Columbia inappropriately prescribe opioid analgesics and antibiotics.    69 This may be contributing to the global problems of opioid dependence and addiction, and bacterial resistance to antibiotics.    In the future, the scope of this survey should be expanded to assess the decisions of general dentists in other regions of British Columbia to see if they are similar to the decisions made by general dentists in Vancouver.  The reasons for decisions should also be explored.  It should be determined whether or not the decisions regarding medication use and prescription in endodontics are being made for medico-legal reasons or for a lack of understanding.  Most importantly, guidelines should be established for the province of British Columbia to provide dentists some guidance in this area.    It has been mentioned that one of the limitations of the study was the non-response bias.  Another limitation was encountered with the information received about the dosage of the medications to be recommended or prescribed.  An example of an appropriate response was provided in the survey (eg. 400mg q4h, which equates to 400mg every 4 hours); however, the answered provided varied significantly in their form and interpretation could not be done.  In future studies, a more reliable question should be developed with regards to dosage.  This could be achieved by asking to check different boxes for dosage amounts and frequency.    70 Chapter 6: Conclusions According to the survey of general dentists in Vancouver and endodontists in British Columbia, the following conclusions could be drawn:  1. A substantial proportion of dental professionals prescribed opioid analgesics.   - General dentists tended to prescribe opioid analgesics more often than endodontists. - No apparent differences were found between groups of different gender, clinical experience, or practice location. 2. A substantial proportion of dental professionals prescribed antibiotics. - General dentists prescribed antibiotics significantly more often than endodontists. - No apparent differences were found between groups of different gender, clinical experience, or practice location.   - The respondents to our survey did report prescribing antibiotics less frequently than those of a 1996 study of U.S. dentists.      71 Bibliography  1. Brunton LL, Chabner B, Knollman B, editors. Goodman and Gilman's The Pharmacological Basis of Therapeutics. 12 ed. China: McGraw-Hill; 2011.  2. Merksey H, Bogduk N, editors. Classification of Chronic Pain. 2nd ed. Seattle: IASP Press; 1994.  3. Hargreaves KM, Goodis H, Tay F, editors. Seltzer and Bender's Dental Pulp. 2nd ed. UK: Quintessence; 2012.  4. Buschmann H, Maul C, Sundermann B, Christoph T, Friderichs E. Analgesics: from chemistry and pharmacology to clinical application. Cambridge: Wiley-VCH; 2002.  5. Derbyshire SW, Jones AK, Gyulai F, Clark S, Townsend D, Firestone LL. Pain processing during three levels of noxious stimulation produces differential patterns of central activity. Pain. 1997 Dec;73(3):431–45.  6. Henry MA, Hargreaves KM. Peripheral mechanisms of odontogenic pain. Dent Clin North Am. 2007 Jan;51(1):19–44.  7. Hebbes C, Lambert DG. Non-opioid analgesics. Anaesthesia & Intensive Care Medicine. 2013 Nov;14(11):510–3.  8. Lopshire JC, Nicol GD. The cAMP transduction cascade mediates the prostaglandin E2 enhancement of the capsaicin-elicited current in rat sensory neurons: whole-cell and single-channel studies. J Neurosci. 1998 Aug 15;18(16):6081–92.  9. Pulichino A-M, Rowland S, Wu T, Clark P, Xu D, Mathieu M-C, et al. Prostacyclin antagonism reduces pain and inflammation in rodent models of hyperalgesia and chronic arthritis. J Pharmacol Exp Ther. 2006 Dec;319(3):1043–50.  10. Reinold H, Ahmadi S, Depner UB, Layh B, Heindl C, Hamza M, et al. Spinal inflammatory hyperalgesia is mediated by prostaglandin E receptors of the EP2 subtype. J Clin Invest. 2005 Mar;115(3):673–9.  11. Lewis SC, Langman MJS, Laporte J-R, Matthews JNS, Rawlins MD, Wiholm B-E. Dose-response relationships between individual nonaspirin nonsteroidal anti-inflammatory drugs (NANSAIDs) and serious upper gastrointestinal bleeding: a meta-analysis based on individual patient data. Br J Clin Pharmacol. 2002 Sep;54(3):320–6.  12. Högestätt ED, Jönsson BAG, Ermund A, Andersson DA, Björk H, Alexander JP, et al. Conversion of acetaminophen to the bioactive N-acylphenolamine AM404 via fatty acid amide hydrolase-dependent arachidonic acid conjugation in the nervous system. J Biol   72 Chem. 2005 Sep 9;280(36):31405–12.  13. Mallet C, Barrière DA, Ermund A, Jönsson BAG, Eschalier A, Zygmunt PM, et al. TRPV1 in brain is involved in acetaminophen-induced antinociception. [Internet]. PloS One. 2010;5(9). 14. Larson AM, Polson J, Fontana RJ, Davern TJ, Lalani E, Hynan LS, et al. Acetaminophen-induced acute liver failure: Results of a United States multicenter, prospective study. Hepatology. 2005;42(6):1364–72.  15. Pasternak GW, Pan Y-X. Mu opioids and their receptors: evolution of a concept. Pharmacol Rev. 2013;65(4):1257–317.  16. Martin WR, Eades CG, Thompson JA, Huppler RE, Gilbert PE. The effects of morphine- and nalorphine- like drugs in the nondependent and morphine-dependent chronic spinal dog. J Pharmacol Exp Ther. 1976 Jun;197(3):517–32.  17. College of Pharmacists of British Columbia. Controlled Prescription Program [Internet]. 2011 [cited 2014 Mar 31]. Available from: http://library.bcpharmacists.org/D-Legislation_Standards/D-4_Drug_Distribution/5015-ControlledPrescriptionProgram.pdf 18. Fischer B, Gittins J, Rehm J. Characterizing the “awakening elephant” of prescription opioid misuse in Noth America: Epidemiology, harms, interventions. Contemp Drug Probs. 2008 Jun 1;35:397–426.  19. International Narcotics Control Board. Narcotic Drugs: Estimated World Requirements for 2011 - Statistics for 2009. Vienna; 2010 Jul.  20. International Narcotics Control Board. Report of the International Narcotics Control Board for 2012. Vienna; 2013 Mar.  21. Fischer B, Jones W, Krahn M, Rehm J. Differences and over-time changes in levels of prescription opioid analgesic dispensing from retail pharmacies in Canada, 2005-2010. Pharmacoepidemiol Drug Saf. 2011 Jul 13;20(12):1269–77.  22. Fischer B, Rehm J, Patra J, Cruz MF. Changes in illicit opioid use across Canada. CMAJ. 2006 Nov;175(11):1385–7.  23. Cicero TJ, Inciardi JA, Muñoz A. Trends in abuse of OxyContin® and other opioid analgesics in the United States: 2002-2004. The Journal of Pain. 2005 Oct;6(10):662–72.  24. Substance Abuse and Mental Health Services Administration. Results from the 2003 National Survey on Drug Use and Health: National Findings. Rockville (MD); 2004 Sep. Report No.: DHHS Publication No. SMA 04-3964.  25. Johnson LD, O'Malley PM, Bachman JG, Schulenberg JE. Monitoring the Future: National Results on Adolescent Drug Use. Overview of Key Findings 2005. National   73 Institute on Drug Abuse (NIDA). Bethesda, MD; 2006. Report No.: NIH Publication No. 06-5882.  26. Whiteside LK, Walton MA, Bohnert ASB, Blow FC, Bonar EE, Ehrlich P, et al. Nonmedical prescription opioid and sedative use among adolescents in the emergency department. Pediatrics. 2013 Nov;132(5):825–32.  27. Fischer B, Ialomiteanu A, Boak A, Adlaf E, Rehm J, Mann RE. Prevalence and key covariates of non-medical prescription opioid use among the general secondary student and adult populations in Ontario, Canada. Drug Alcohol Rev. 2013 Jan 11;32(3):276–87.  28. Arora S, Roxburgh A, Bruno R, Nielsen S, Burns L. A cross-sectional analysis of over-the-counter codeine use among an Australian sample of people who regularly inject drugs. Drug Alcohol Rev. 2013 Nov;32(6):574–81.  29. Manchikanti L. National drug control policy and prescription drug abuse: facts and fallacies. Pain Physician. 2007 May;10(3):399–424.  30. Hurwitz W. The challenge of prescription drug misuse: A review and commentary. Pain Medicine. 2005;6:152–61.  31. Paulozzi LJ, Budnitz DS, Xi Y. Increasing deaths from opioid analgesics in the United States. Pharmacoepidemiol Drug Saf. 2006 Sep;15(9):618–27.  32. Sproule B, Brands B, Li S, Catz-Biro L. Changing patterns in opioid addiction: characterizing users of oxycodone and other opioids. Can Fam Physician. 2009 Jan;55(1):68–9–69.e1–5.  33. Marshall JG. Consideration of steroids for endodontic pain. Endodontic Topics. 2002 Nov;3(1):41–51.  34. Bayles KW. The bactericidal action of penicillin: new clues to an unsolved mystery. Trends Microbiol. 2000 Jun;8(6):274–8.  35. Standing Medical Advisory Committee. The Path of Least Resistance. London (UK); 1998.  36. Wrigley T, Tinto A, Majeed A. Age and sex specific antibiotic prescribing patterns in general practice in England and Wales, 1994 to 1998. Health Statistics Quarterly. 2002;14:14–20.  37. American Dental Association Council on Scientific Affairs. Antibiotic use in dentistry. J Am Dent Assoc. 1997 May 1;128(5):648–8.  38. Bidault P, Chandad F, Grenier D. Risk of bacterial resistance associated with systemic antibiotic therapy in periodontology. Journal of the Canadian Dental Association. 2007 Oct;73(8):721–5.    74 39. Smith RD, Coast J. Antimicrobial resistance: a global response. Bull World Health Organ. 2002;80(2):126–33.  40. Sweeney LC, Dave J, Chambers PA, Heritage J. Antibiotic resistance in general dental practice - a cause for concern? J Antimicrob Chemother. 2004 Apr;53(4):567–76.  41. Hargreaves KM, Cohen S, Berman L, editors. Cohen's Pathways of the Pulp. 10 ed. St. Louis: Mosby; 2011.  42. Glickman G, Schweitzer JL. Endodontics: Colleagues for Excellence - Endodontic Diagnosis. American Association of Endodontists; 2013.  43. AAE Consensus Conference Recommended Diagnostic Terminology. Journal of Endodontics. Elsevier Ltd; 2009 Dec 1;35(12):1634.  44. Pak JG, White SN. Pain prevalence and severity before, during, and after root canal treatment: a systematic review. Journal of Endodontics. 2011 Apr;37(4):429–38.  45. Keiser K, Hargreaves KM. Building effective strategies for the management of endodontic pain. Endodontic Topics. 2002;3(1):93–105.  46. Rosenberg PA. Clinical strategies for managing endodontic pain. Endodontic Topics. 2002;3(1):78–92.  47. Holstein A, Hargreaves KM, Niederman R. Evaluation of NSAIDs for treating post‐endodontic pain. Endodontic Topics. 2002;3(1):3–13.  48. Harrison JW, Baumgartner IC, Zielke DR. Analysis of interappointment pain associated with the combined use of endodontic irrigants and medicaments. Journal of Endodontics. 1981.  49. O'Keefe EM. Pain in endodontic therapy: preliminary study. Journal of Endodontics. 1976.  50. Genet JM, Wesselink PR, Vanvelzen S. The Incidence of Preoperative and Postoperative Pain in Endodontic Therapy. Int Endod J. 1986 Sep;19(5):221–9.  51. The Oxford League Table of Analgesic Efficacy. Bandolier Journal [Internet]. 2007. Available from: http://www.medicine.ox.ac.uk/bandolier/booth/painpag/acutrev/analgesics/lftab.html 52. Menhinick KA, Gutmann JL, Regan JD, Taylor SE, Buschang PH. The efficacy of pain control following nonsurgical root canal treatment using ibuprofen or a combination of ibuprofen and acetaminophen in a randomized, double-blind, placebo-controlled study. Int Endod J. 2004 Aug;37(8):531–41.  53. Daniels SE, Goulder MA, Aspley S, Reader S. A randomised, five-parallel-group,   75 placebo-controlled trial comparing the efficacy and tolerability of analgesic combinations including a novel single-tablet combination of ibuprofen/paracetamol for postoperative dental pain. Pain. 2011 Mar;152(3):632–42.  54. Dorn SO, Moodnik RM, Feldman MJ, Borden BG. Treatment of the endodontic emergency: a report based on a questionnaire-part I. Journal of Endodontics. 1977 Mar;3(3):94–100.  55. Gatewood RS, Himel VT, Dorn SO. Treatment of the endodontic emergency: a decade later. Journal of Endodontics. 1990 Jun;16(6):284–91.  56. Lee M, Winkler J, Hartwell G, Stewart J, Caine R. Current Trends in Endodontic Practice: Emergency Treatments and Technological Armamentarium. Journal of Endodontics. 2008 Jan 1;35(1):35–9.  57. Fouad AF. Are antibiotics effective for endodontic pain? Endodontic Topics. 2002;3(1):52–66.  58. Haapasalo M, Endal U, Zandi H, Coil JM. Eradication of endodontic infection by instrumentation and irrigation solutions. Endodontic Topics. 2005.  59. Keenan J, Farman A, Fedorowicz Z, Newton J. A Cochrane Systematic Review Finds No Evidence to Support the Use of Antibiotics for Pain Relief in Irreversible Pulpitis. Journal of Endodontics. 2006 Feb;32(2):87–92.  60. Longman LP, Preston AJ, Martin MV, Wilson NH. Endodontics in the adult patient: the role of antibiotics. J Dent. 2000 Nov;28(8):539–48.  61. Epstein JB, Chong S, Le ND. A survey of antibiotic use in dentistry. J Am Dent Assoc. 2000 Nov;131(11):1600–9.  62. Whitten BH, Gardiner DL, Jeansonne BG, Lemon RR. Current trends in endodontic treatment: report of a national survey. J Am Dent Assoc. 1996 Sep;127(9):1333–41.  63. Yingling N, Ellenbyrne B, Hartwell G. Antibiotic Use by Members of the American Association of Endodontists in the Year 2000: Report of a National Survey. Journal of Endodontics. 2002 May;28(5):396–404.  64. Rodriguez-Núñez A, Cisneros-Cabello R, Velasco-Ortega E, Llamas-Carreras JM, Tórres-Lagares D, Segura-Egea JJ. Antibiotic use by members of the Spanish Endodontic Society. Journal of Endodontics. 2009 Sep;35(9):1198–203.  65. Nabavizadeh MR, Sahebi S, Nadian I. Antibiotic prescription for endodontic treatment: General dentist knowledge + practice in Shiraz. Iran Endod J. 2011;6(2):54–9.  66. Standards of Practice. Canadian Academy of Endodontics; 2012.   76 67.   Morrow S. Endodontics: Colleagues for Excellence - Use and Abuse of Antibiotics. American Association of Endodontists; 2012.  68. Berge TI. The Use of a Visual Analog Scale in Observer Assessment of Postoperative Swelling Subsequent to 3rd-Molar Surgery. Acta Odontologica Scandinavica. 1989 Jun;47(3):167–74.  69. Holland CS. Development of a Method of Assessing Swelling Following 3rd Molar Surgery. British Journal of Oral Surgery. 1979;17(2):104–14. 70. Evans SJ. Good surveys guide. British Medical Journal. BMJ Group; 1991 Feb 9;302(6772):302–3.  71. Baur EJ. Response bias in a mail survey. Public Opinion Quarterly. 1947;11(4):594–600.  72. Armstrong JS, Overton TS. Estimating nonresponse bias in mail surveys. Journal of Marketing Research. 1977 Aug;14:396–402.  73. Heberlein TA, Baumgartner R. Factors affecting response rates to mailed questionnaires: A quantitative analysis of the published literature. American Sociological Review. 1978 Aug;43(4):447–62.  74. Barclay S. Not another questionnaire! Maximizing the response rate, predicting non-response and assessing non-response bias in postal questionnaire studies of GPs. Family Practice. 2002 Feb 1;19(1):105–11.  75. van Teijlingen ER, Rennie A-M, Hundley V, Graham W. The importance of conducting and reporting pilot studies: the example of the Scottish Births Survey. Journal of Advanced Nursing. 2001 May;34(3):289–95.  76. Hansen MH, Hurwitz WN. The Problem of Non-Response in Sample Surveys. Journal of the American Statistical Association. 1946 Dec;41(236):517–29.  77. Etter J-F, Perneger TV. Analysis of non-response bias in a mailed health survey. Journal of Clinical Epidemiology. 1997 Oct;50(10):1123–8.  78. Goyder JC. Further evidence on factors affecting response rates to mailed questionnaires. American Sociological Review. 1982.  79. Hartge P. Raising response rates: getting to yes. Epidemiology. 1999 Mar;10(2):105–7.       77 Appendices  Appendix A      78 Appendix B                                   Fax completed questionnaire to (604)398-2757!     1!Dear Doctor,  You are invited to participate in a research study conducted by the Department of Endodontics at U.B.C. under the supervision of Dr. Jeffrey Coil and Dr. Rene Buttar.  You responses will be CONFIDENTIAL.  This study will help us determine what the current trends are with regards to prescribing medications before, during, and after endodontic treatments.  One of the objectives is to prepare guidelines on this topic.    If you have any questions about the study please contact Dr. Rene Buttar at (604) 655-8189.  Your participation in this study is voluntary.  Completing and returning this questionnaire implies you have consented.  Please completely answer each question.  Please fax the filled questionnaire to Dr. Rene Buttar at (604)398-2757.  Alternatively, you can email it to endosurvey2013@gmail.com.    Are you currently practicing as 1  A general dentist        (check the appropriate box)  2  An endodontist     3  Other (specify) __________   For how many years have you practiced dentistry?  __________ years      (indicate the number of years)   Specify your gender  1  Female (check the appropriate box) 2  Male   If you are a general dentist, where is your primary office located? 1  Western half of Vancouver   (check the appropriate box, using the map below as a guide)   2  Eastern half of Vancouver      79   80   81  

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.24.1-0167056/manifest

Comment

Related Items