Effects of Various Cements' Retention of Fixed Implant Supported Restorations

Objectives: To investigate the physical retention of different cements on 1 unit and 3-unit implant supported restorations before and after thermal cycling Methods: Twenty maxillary resin models with a single missing tooth and three missing teeth were fabricated and implants were placed. Cast crown and bridge copings were cemented to Strauman solid abutments with seven cements. Specimens were placed in a humidifier at 37 0 C for 24 hours and then half of them subjected to thermal cycles (TC). The tensile force measured using the universal testing machine with a crosshead speed of 0.5 mm/min. The retentions force required to remove the specimens was recorded and the data submitted to three way ANOVA, followed by LSD post hoc test (P=.05).Results: The retentive strengths were measured in descending order of Multilink Implant (M), Kavitan Cem (KC), Adhesor Carbofine(AC), Premier Implant(P), Adhesor (A), Relyx Temp (RT) and Cavex (C)before and after TC both one unit restorations (OUR) and three unit restorations (TUR). The bond strength was statistically higher TUR than OUR before and after TC (P<.05) and there was statistically significant differences between cements for all groups before and after TC (P<.05). Both groups showed statistically significant decrease bond strength after thermal cycling (P<.05) and the most decreased bond strength were seen for C and RT for OUR and C, RT and KC for TUR (P<.05). Conclusions: The bond strength value was higher TUR and thermal cycling was reduced the bond strength of cements especially C, RT and KC.