Effect of cement, implant connection, and aging on the retention strength of zirconia crowns to Ti-base

Purpose: To analyze the influence of the type of cement, aging, and implant connection regarding the Institute of Excellence in Teaching and Research-IETR Institute of Excellence in Teaching and Research-IETR retention capacity of zirconia crowns cemented onto the Titanium base abutment Material and methods: The specimens was divided into four groups: Ti-Base External Hexagon 5,0x4,7x1,0 mm (n=20) or Ti-Base Morse Taper 5,0x4,7x1,5 mm (n=20), temporary or definitive cement, and mechanical aging (with or without). All the samples underwent a tensile test. Results: Data analysis was assessed using the Shapiro-Wilk, three-way ANOVA with repeated measures, and Tukey's test (P < 0.05). The failure mode was also recorded. The Morse taper implants presented a statisti-cally significantly higher average retention strength than the external hexagon implants. Groups III and IV presented the highest value compared to the other groups (565 and 491 N). Most mixed failures were found for all groups. Conclusion: Mechanical aging imped-ed the retention force of milled zirconia crowns cemented on titanium base abutments with resin cement on Morse taper implants had greater retention force compared to exter-nal hexagon implants.