مجله دانشکده دندانپزشکی اصفهان (Jan 2008)
Comparison of convergence angles achieved in teeth prepared by under and postgraduate students for full veneer crowns, In Isfahan dental school
Abstract
Introduction: Different factors can affect the retention of full veneer crowns such as clinical lengthof crown, diameter of tooth, angle of convergence, type of restoration and the cement. The aim ofthis study was assessment of the convergence angles of tooth preparations for full coverage crownamong dentistry students.Methods and materials: In this observational- cross sectional study, 210 dies from preparedanterior and posterior teeth by under graduate and postgraduate students were randomly selected.In the two groups, the mesiodistal and buccolingual angles of the dies were measured withstereomicroscope and moticam camera and compared with each other. The results were analyzedby t-test via SPSS- 11.5 software.Results: The total average convergence angle was 23.8 ± 8.6 degrees for the preparationsperformed by undergraduate students and 22.4 ± 9.0 for postgraduate group. The averageconvergence angle for anterior preparations was 24.4 ± 8.1 degrees in undergraduate group and20.2 ± 7.7 degrees in postgraduate group and for posterior preparations it was 23.6 ± 8.8 degreesin under graduate group and 24.1 ± 9.6 degrees in other group. Differences in convergence anglesof anterior preparations between two groups were significant (p value = 0.02), but for posteriorpreparations and other preparation were not statistically significant.Conclusion: The total average convergence angle of all preparations and posterior preparations intwo groups were the same, But it was significantly greater in anterior preparations prepared byundergraduate students. In any case, the findings were similar to some of previous studies.Key words: Angle of convergence, Retention, full crown.
