The effect of connector design on cement retention in an implant and natural tooth-supported fixed partial denture

This study investigated the effect of connector design, rigid or nonrigid, on cement retention in a combined implant and natural tooth-supported fixed partial denture. A prepared natural tooth was placed in a Plexiglas block in a manner that it could move approximately the same as a healthy premolar. An endosseous implant was placed in the block so that it was immobile. Joining the prepared tooth and implant was a fixed partial denture that could be made rigid or nonrigid. The natural tooth retainer was cemented to the prepared tooth, and the implant retainer was affixed to the implant fixture with a gold screw. One year of stress was applied to the fixed partial denture by a force simulation machine. Twenty randomly ordered tests were completed, 10 of each connector design. Retentive values for the cemented retainers were recorded and statistically compared by use of Student's independent t test. No significant difference in cement retentive strength between designs was found (p less than 0.05).