Comparative in vitro study of cementing techniques for implant-supported restorations

Statement of problem: Various techniques are used to cement implant-supported restorations. Excess residual cement is a concern.

Purpose: The purpose of this in vitro study was to evaluate 3 techniques for cementing implant-supported restorations.

Material and methods: Twelve crowns and implant-abutment complexes (IAC) were cemented with 3 techniques: technique 1, a certain amount of cement evenly placed and excess cement removed with an explorer; technique 2, a smaller amount of cement without removal of excess cement; technique 3, a resin abutment replica used for excess cement removal after using a large amount of cement. Each specimen was treated with each technique 3 times. Precementing discrepancies (predis) and postcementing discrepancies (postdis) between IACs and crowns and the postcementing linear roughness (Ra and Rz) on designated junction areas of each specimen were measured. Tensile strength of the specimens was recorded with a universal testing machine at a crosshead speed of 0.5 mm/min. Repeated measures analysis with mixed models was used for differences among the 3 cementing techniques (α=.05).

Results: Compared with techniques 1 and 2, the specimens with technique 3 showed significantly lower mean differences between postdis and predis and Ra and Rz and higher mean tensile strength (P<.05).

Conclusions: The application of a resin abutment replica for the cementation of implant-supported restorations decreased the discrepancy between the restoration and abutment, reduced cement residue, and increased restoration retention.