Convergence Angle Of Prepared Teeth For Crowns: A comparison at College of Dentistry, Qassim University Saudi Arabia

Abstract

Objective:To compare clinically practiced convergence angle values of tooth preparation with recommended values, and also the effect of tooth position and operator experience on convergence angle.

Study Design: Cross Sectional analytical study

Place and Duration of Study:The study was carried out at the Dental clinics, Qassim University dental clinic, from August 2016 to February 2017.

Methodology: A minimum of 53 crown preparation dies were collected which were prepared by students and interns of operative dentistry. AutoCAD 2017 software was used for measurement of convergence angle. One sample t-test was applied to compare the mean practiced convergence angle values with its recommended values. One way ANOVA was applied to measure difference in convergence angle values with respect to operator experience and tooth type with the level of significance being =0.050.

Results:Mean reported convergence angle value was 27.62, which was significantly greater (p < 0.001) than the recommended values. Statistically significant difference in convergence angle was found between anterior vs. molar teeth and between premolars vs. molar teeth (p=0.0001 and p=0.002, respectively).

Conclusion:There was a considerable disparity between the convergent angles values recorded in this study and the recommended guidelines. Measured convergence angle values were greater for posterior teeth as compared to the anterior teeth.

Key words: Convergence angle.   Taper.   Metal ceramic crowns.   Anterior teeth.   Posterior teeth.