Assessment of Retention and Resistance Form of Tooth Preparations for All Ceramic Restorations using Digital Imaging Technique.

Aim: This in vitro study evaluated the resistance form of die preparations for all ceramic restorations and, thereby, explored the concept of effective taper and its correlation between the ideal in theory and actual in the clinical situation by analyzing the digital images of the die preparations.

Materials And Methods: Scanned digital images of 114 die preparations for all ceramic restorations (n = 114) were collected from a dental laboratory. All the images were also analyzed digitally using Adobe Photoshop® software to analyze the degree of taper (angle of convergence) of each preparation and then applied the Zuckerman's circle, and the Lewis perpendicular methods were used to measure the resistance form.