Retention Strength after Compressive Cyclic Loading of Five Luting Agents Used in Implant-Supported Prostheses

The purpose of this study was to evaluate and compare the retention strength of five cement types commonly used in implant-retained fixed partial dentures, before and after compressive cyclic loading. In five solid abutments screwed to 5 implant analogs, 50 metal Cr-Ni alloy copings were cemented with five luting agents: resin-modified glass ionomer (RmGI), resin composite (RC), glass ionomer (GI), resin urethane-based (RUB), and compomer cement (CC). Two tensile tests were conducted with a universal testing machine, one after the first luting of the copings and the other after 100,000 cycles of 100 N loading at 0.72 Hz. The one way ANOVA test was applied for the statistical analysis using the post hoc Tukey test when required. Before and after applying the compressive load, RmGI and RC cement types showed the greatest retention strength. After compressive loading, RUB cement showed the highest percentage loss of retention (64.45%). GI cement recorded the lowest retention strength (50.35 N) and the resin composite cement recorded the highest (352.02 N). The type of cement influences the retention loss. The clinician should give preference to lower retention strength cement (RUB, CC, and GI) if he envisages any complications and a high retention strength one (RmGI, RC) for a specific clinical situation.