UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

10-mdp (10-methacryloyloxydecyl dihydrogen phosphate)-mediated adherence of resin composite luting agent to rapid-fired zirconia - a fracture mechanics approach El Najjar, Mai


Introduction: The success of all-ceramic restorations depends on a strong and stable bond to dental hard tissues, achievable by adhesive cementation. 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) is a suitable primer for zirconia-based restorations. Adherence to zirconia imparted by 10-MDP has been investigated with shear and micro-tensile bond strength tests. Objective: This study aimed to apply fracture mechanics methodology to investigate the effect of 10-MDP on the adherence of a resin composite luting agent (RCLA) to recently introduced rapid-fired zirconia (RFZ). Materials & Methods: Interfacial fracture toughness (IKIC) was determined with the notchless triangular (NTP) specimen KIC test. Seventy-eight NTP specimens were cut and ground from RFZ blocks (Katana, Kuraray, Japan), followed by rapid firing. The samples were then cut into halves and allocated to three groups, each with a different surface preparation protocol prior to bonding: 1) Control, no treatment; 2) MDP, 5 % 10-MDP ethanol primer; 3) Silane, Bisco Bis-Silane. All samples were bonded with an RCLA (3M RelyX Veneer Cement) and stored in water at 37 °C. IKIC was determined after 24 h and 90 d storage. The results were analyzed with an independent samples t-test (α= 0.05). Scanning electron microscopy fractographic analysis was performed on representative fractured samples from each group. Result: At 24 h, only the MDP group could be tested [IKIC (1.34 ± 0.40) MPa·m¹ᐟ²]. Samples from the other two groups were de-bonded before testing. For the MDP group, crack propagation occurred cohesively through the RCLA. After 90 d storage, the IKIC of the MDP group dropped significantly, to (0.88 ± 0.3) MPa·m¹ᐟ². SEM images of fractured surfaces (24 h and 90 d) showed the presence of RCLA on both halves, indicative of cohesive failure within RCLA. Conclusion: The fracture mechanics analysis confirmed the suitability of MDP as a primer for RFZ. Even though there was a significant decrease in IKIC upon storage, failure took always place cohesively in the RCLA.

Item Media

Item Citations and Data


Attribution-NoDerivatives 4.0 International