# Evaluating the Impact of Pontic Geometry on Load to Failure and Displacement in Implant-Supported Monolithic Zirconia Prostheses: An In Vitro Analysis

## TL;DR

This study shows that the shape of dental prostheses affects how well they resist breaking and bending under stress.

## Contribution

The study introduces new insights into how pontic geometry impacts the mechanical performance of zirconia dental prostheses.

## Key findings

- Pontic geometry significantly affects the fracture resistance of zirconia prostheses.
- Different geometries lead to statistically significant differences in load to failure and displacement.
- Concave and narrow pontics showed distinct mechanical behavior compared to flat and wide ones.

## Abstract

The pontic design may influence the load-to-failure performance of fixed implant-supported screw-retained monolithic zirconia prostheses. This study aimed to evaluate the effect of pontic geometry on the fracture resistance of such restorations. Forty restorations were designed using dental CAD software and divided into four groups (n = 10 each): (A) Flat + Wide—pontics with a flat contour, 10 mm in width and 8 mm in height; (B) Concave + Wide—pontics with a concave contour, 10 mm in width and 5.5 mm in height; (C) Flat + Narrow—pontics with a flat contour, 6 mm in width and 8 mm in height; and (D) Concave + Narrow—pontics with a concave contour, 6 mm in width and 5.5 mm in height. All specimens underwent thermal and mechanical cycling, followed by a fracture load test using a three-point bending setup. Maximum fracture loads and displacements were analyzed using one-way ANOVA. Statistically significant differences were observed among the groups for both load to failure (p = 0.001) and displacement (p = 0.002). These findings indicate that pontic geometry significantly influences the fracture resistance and deformation behavior of monolithic zirconia prostheses.