Clinical evaluation of the effect of implant-supported and implant retained distal extension removable partial dentures on the supporting structures

Abstract

AIM: The objective of the study is to evaluate and compare the effect of implant-supported versus implant-retained removable partial denture (RPD) restoring Kennedy’s class I cases on the supporting structures by measuring modified gingival index, probing depth for both abutment teeth and implant, as well as measuring marginal bone loss for implants. SUBJECTS AND METHODS: Twelve patients; who had Kennedy class I mandibular partially edentulous ridge extending distal to the first or second premolar, all patients have full dentition in the maxillary arch or restored by fixed restoration, all patients were selected from the outpatient clinic, Prosthodontics Department, Faculty of Dentistry, Minia University. The patients were classified into two equal groups; according to the implant superstructures either dome-shaped abutment or ball and socket attachment. Each patient of both groups had two implants in the second molar position (one in each side) and received RPD of the same design. Patients were followed up for 1 year clinically and radiographically. Group I: six patients received RPD supported by dome-shaped short abutments. Group II six patients received RPD retained by ball and socket attachments. RESULTS: Results revealed that there was no statistically significant difference between the two groups regarding modified gingival index and probing depth around the abutment teeth and implant abutment, there was Significant increase in marginal bone loss in Group II implant-retained with ball abutment than Group I implant-supported with dome-shaped abutment. CONCLUSION: The use of dome-shaped abutment or ball and O-ring attachment have the same effect on gingival index and probing depth around natural abutments and implants in Kennedy class I mandibular situations, The use of dome-shaped abutment produce less marginal bone loss than ball abutment.