Versacryl versus Chrome-Cobalt Clasps in Implant- Supported Partial over-Dentures

Abstract

This study was conducted to evaluate the effect of the type of clasp assembly used in toothimplant-supported partial over-dentures on the supporting structures of the abutment and the implant. Fourteen partially edentulous male patients, mandibular Kennedy class II, were selected with #21 or #28 as the last standing tooth. Each patient received a skeleton partial over-denture supported by a single root-form implant in the area of #18 or #31. Patients were divided into two equal groups; group I received an implant-supported partial over-denture with a metallic gingivally approaching retentive arm, while group II received the same denture design but with a thermoelastic resin (Versacryl) gingivally approaching retentive arm. Evaluation of the terminal abutment and the implant was carried out both clinically and radiographically at the time of insertion, six and twelve months later. There was no statistically significant difference (P>0.05) in the gingival index scores or bone height changes in both groups. However, after twelve months, patients of group II showed a statistically significantly lower mean amount of bone loss (P≤0.05) compared to those of group I. Similarly, no statistically significant difference (P>0.05) was observed between the mean bone density measurements in both groups after six months. However, after twelve months, patients of group II showed a statistically significant increase in the mean bone density measurements (P≤ 0.05) compared to those of group I. The use of thermoelastic clasps was better accepted by the patients. Both, the implants and the abutments reacted more favorably with the use of Versacryl clasps.