Objective: Evaluation of implant abutment surface area, coping design, and type of cement on crown retention. Methods: 5mm and 6mm diameter one-piece titanium implant abutments were used. Waxing sleeves were made with either 0µm (PMMA GC RESIN) or 60µm cement space (polycarbonate waxing sleeve). The sleeve was waxed to the abutment replica, a sprue attached, invested and cast in a PFM alloy (por 76, Mowery). Each abutment was vertically positioned in an implant replica and thimble crowns cemented using one of the four cements: (T) TempBond, (R) Rely X, (ZP) Zinc Phosphate, or (P) Panavia (n=10 by specimens/cement/abutment/coping type). Samples were thermo cycled for 300 cycles with 30 second at 5C and 55C. Tensile bond strength was evaluated with a Zwick MTS machine and data analyzed by ANOVA (α<0.05). Results: Based on the three-way ANOVA, data indicated the type of cement on the tensile bond strength was significant as well the diameter of the abutment (p<0.01). However, data indicates cement space was not significant (p=0.94). Two-way ANOVA observed: 1) significant interactions between type of cement and the type of cast coping for both diameters, and between type of cement and diameter for GC cast coping (p<0.01); and 2) no significant interaction was found between type of cements and diameter of the abutment under provided cast coping condition (p=0.19). Under provided cast coping condition, Tukey's HSD test indicated the mean strength for diameter 6mm was significantly higher (597.50±303.33) than the mean strength for diameter 5mm (456.37 ± 230.75), while the mean strength for Panavia (769.01 ± 238.90) was significant higher than the other three cements (R: 546.08 ± 222.27; ZP: 464.57 ± 173.99; T:328.09 ± 273.12). Conclusions: The type of cement, coping used, as well as the size of abutment diameter influence crown retention. (Supported by Astra Tech AB, Mölndal Sweden).

Back to the Implantology Research Program
Back to the ADEA/AADR/CADR Meeting & Exhibition (March 8-11, 2006)

Top Level Search