Comparing the quality of dental preparation for students of Al-Rasheed Private University

Abstract

Introduction & aim: The durability of the prosthesis in the service of the patient and its stay in the mouth is the only criterion for the success of fixed prosthesis in the oral cavity, to achieve this, the prepared tooth must have a geometric shape that ensures good retention for the compensation that will rest on it. It is known that the retention is affected by the degree of inclination of the axial walls, their height, and the type of cement. This is where the idea of ​​this study started to evaluate the quality of preparation by students of Al-Rasheed Private University, which were randomly selected (the degree of inclination - the height of the abutment - the reduction of the occlusal surface) to see the extent to which the results match the academic standards. Materials & methods: 60 gypsum samples containing a lower first molar prepared to receive a full cast crown were achieved by students in laboratories at the College of Dentistry - Al-Rasheed Private University. We measure the degree of inclination for axial walls prepared (mesial and distal wall) and the height of the abutment by the CAD\CAM scanner.  We have a three-dimensional image of the prepared tooth to be processed on the computer using the Exco Cad program, and then we measure the angle of convergence Results: It was found that the lowest value of the preparation angle was 14 degrees, and the largest angle was 35 degrees, with an arithmetic mean of 22.28 degrees. As for the geometric shape of the occlusal surface, the features were missed by 23.33%, the features were less clear by 55%, and the features were clear by 21.66%. As for the height of the abutment, it was between 3.5 and 5.1 mm.

Conclusions: There is an excessive wall inclination compared to the limits recommended by many international studies in this field, which greatly affects the retention negatively. There is wasting of dental tissues during the reduction.