The influence of titanium-base abutment geometry and height on mechanical stability of implant-supported single crowns.

ABSTRACT

AIM: This study aimed to investigate the influence of titanium base (ti-base) abutment macro- and micro-geometry on the mechanical stability of polymer-infiltrated ceramic network (PICN) screw-retained implant-supported single crowns (iSCs). MATERIALS AND METHODS: Twelve specimens per group were used, comprising six different implant/ti-base abutment combinations restored with PICN iSCs Nb-T (gingival height [GH] 1.5 mm, prosthetic height [PH] 4.3 mm), CC (GH 0.8 mm, PH 4.3 mm), CC-P (GH 0.8 mm, PH 7 mm), Nb-V (GH 1.5 mm, PH 6 mm), St (GH 1.5 mm, PH 5.5 mm), and Th (GH 0.5 mm, PH 9 mm). The specimens underwent thermo-mechanical aging, and those that survived were subsequently subjected to static loading until failure. The data were analyzed using a one-way ANOVA test followed by Tukey post hoc test (α = .05). RESULTS: All specimens survived thermo-mechanical aging without complications, namely, visible cracks, debonding, or screw loosening. Th group demonstrated the highest strength values among all the groups, with significant differences compared to Nb-T (p < .05), CC (p < .001), and St (p < .001). Additionally, CC-P group exhibited significantly superior fracture strength results compared to CC (p < .05) and St (p < .05). CONCLUSION: The choice of ti-base, particularly prosthetic height, had a significant influence on fracture resistance of PICN iSCs. Nevertheless, the height or geometrical features of the ti-base did not exhibit a significant influence on the mechanical behavior of the iSC/ti-base assembly under thermomechanical loading, as all specimens withstood the aging without complication or failure.