THE EFFECT OF FABRICATION TECHNIQUE AND CEMENT TYPE ON THE RETENTION STRENGTH OF IMPLANT SUPPORTED CROWNS

Abstract

Objectives: The purpose of this study was to compare the retention strength of implant-supported crowns produced by traditional lost-wax, direct metal laser sintering, CAD/CAM technique by using three different luting cements. Materials and Methods: Ninety standard titanium abutments screwed to analogs then mounted in acrylic resin. Samples divided into three main groups according to the manufacturing technique (N=30). Then groups divided into three subgroups based on the cement type used (n=10). The specimens subjected to the pull-out test by using an universal testing machine at a 1 mm/min crosshead speed. The highest pull-out strength values were recorded in Newton and statistical analyzes were performed by using Two-way ANOVA test and multiple comparison test with Bonferroni correction at a significance level of 0.05. Results: The two-way analysis of variance revealed that the fabrication technique and cement type had a significant effect on pull-out strength (p<0.05). However, the interaction of fabrication technique and cement type did not significantly affect the pull-out strength of groups(p>0.05). The highest pull-out strength was found in the laser sintering group, while the conventional technique had the lowest values. Within the subgroups self-adhesive resin cement had the highest pull-out strength, traditional cement subgroup had the lowest. Conclusions: Fabrication technique and cement type have statistically significant effect on the retention of the implant-supported crowns.