مقايسه زاويه هاي تقارب دندان هاي آماده شده جهت روكش كامل تاجي در گروه دانشجويان عمومي و تخصصي در دانشكده دندان پزشكي اصفهان

Comparison of Convergence Angles Achieved in Teeth Prepared by Under and Postgraduate Students for Full Veneer Crowns, in Isfahan Dental School

Introduction: Different factors can affect the retention offull veneer crowns such as clinical length ofcrown, diameter oftooth, angle ofconvergence, type ofrestoration and the cement. The aim of this study was assessment ofthe convergence angles oftooth preparations for full coverage crown among dentistry students. Methods and materials: In this observational- cross sectional study, 210 dies from prepared anterior andposterior teeth by under graduate andpostgraduate students were randomly selected. In the two groups, the mesiodistal and buccolingual angles ofthe dies were measured with stereomicroscope and moticam camera and compared with each other. The results were analyzed by t-test via SPSS- 11.5 software. Results: The total average convergence angle was 23.8 ± 8.6 degreesfor the preparations performed by undergraduate students and 22.4 ± 9.0 for postgraduate group. The average convergence anglefor anterior preparations was 24.4 ± 8.1 degrees in undergraduate group and 20.2 ± 7.7 degrees in postgraduate group andfor posterior preparations it was 23.6 ± 8.8 degrees in under graduate group and 24.1 ± 9.6 degrees in other group. Differences in convergence angles ofanterior preparations between two groups were significant (p value == 0.02), but for posterior preparations and other preparation were not statistically significant. Conclusion: The total average convergence angle ofall preparations andposterior preparations in two groups were the same, But it was significantly greater in anterior preparations prepared by undergraduate students. In any case, the findings were similar to some ofprevious studies.