João Pitta

Objectives The aim of this study was to evaluate the effect of sterilization on the retention forces of lithium disilicate (LD) and polymer‐infiltrated ceramic network (PICN) crowns bonded to titanium base (Ti‐base) abutments. Materials and methods Forty LD and 40 PICN crowns were milled and then bonded to 80 Ti‐bases with two resin composite cements: Multilink Hybrid Abutment (mh) and Panavia V5 (pv) for a total of 8 groups ( n = 10). Half of the specimens (test) underwent an autoclaving protocol (pressure 1.1 bar, 121°C, 20.5 min) and the other half not (control). Restorations were screw‐retained to implants, and retention forces (N) were measured with a pull‐off testing machine. The surfaces of the Ti‐bases and the crowns were inspected for the analysis of the integrity of the marginal bonding interface and failure mode. Student's t ‐test, chi‐square test, and univariate linear regression model were performed to analyze the data ( α = 0.05). Results The mean pull‐off retention forces ranged from 487.7 ± 73.4 N to 742.2 ± 150.3 N. Sterilized groups showed statistically significant overall higher maximum retention forces ( p < .05), except for one combination (LD + mh). Sterilization led to an increased presence of marginal gaps and deformities compared to no‐sterilization ( p < .001), while no statistically significant relationship was found between failure mode and sterilization ( p > .05). Conclusions Sterilization may have a beneficial effect on the retention forces of LD and PICN crowns bonded to titanium base abutments, although it may negatively influence the integrity of the marginal bonding interface.