UBC Theses and Dissertations
Effect of stent marker materials on the localization of cross-sectional images using spiral tomography Orpe, Elaine
With the increase in endosseous dental implant placement there is an increasing demand for cross-sectional imaging of the jaws to facilitate treatment planning of the patient. While there are many articles recommending different types of marker materials in guide stents to be used for this imaging, no quantitative comparisons of the efficacy of such materials have been published. The purpose of this study was to compare different types of marker materials for radiographic guide stents for conventional spiral tomography. Differences in the ability of observers to localize cross-sectional images relative to longitudinal images with the different types of markers were determined. Radiographic guide stents for dried human mandibles and one metatarsal bone were fabricated to accept acrylic cylinders with different marker materials in the same relative position. These were imaged using conventional spiral tomography and observers were asked to localize the cross-sectional images on corresponding longitudinal images using the markers as guides. A pilot study confirmed that there were statistically significant differences in the mean absolute error of slice localization by observers for different marker materials. The pilot study also confirmed that any type of marker resulted in much less mean absolute error in slice localization than use of no marker. The definitive study found statistically significant differences in mean error for slice localization not only for different types of markers, but also for the location of the tomographic slice and for the stents made for different bones.