Assessment of Thermoelastic Retainer on the Abutment Supporting Structure in Bilateral Distal Extension Cases

Abstract

Fourteen partially edentulous patients were cautiously selected to avoid factors that may adversely affect the results of this study. The selected patients exhibited bilateral distal extension mandibular edentulous areas with the first or second premolar as the last standing abutments. All the selected patients were rehabilitated by mandibular removable partial dentures retained by RPI clasp assembly. According to material used to construct the retentive arm of the RPI clasp assembly the selected patients were randomly divided into two equal groups: • Group I: For patients of this group cobalt chromium retentive clasp arm was constructed on the principal abutments. • Group II: For patients of this group acetal resin retentive clasp arm was constructed on the principal abutments. Follow up and data collections were performed at the time of denture insertion, six, and twelve months after insertion. The effect of each retainer on the abutments supporting structures was evaluated by measuring: 1. Crestal bone height changes around the abutment teeth. 2. Pocket depth around abutments. Digital panoramic radiograph was taken at the time of denture insertion and at recall appointments (six and twelve months post insertion) for assessment of bone height change mesial and distal to the principal abutments. Pocket depth was measured by graduated periodontal probe From the results obtained from this study showed - There was insignificant bone loss around the abutment teeth for all patient at the end of the follow up period. - Although more change in bone height for the abutments bearing RPI cast retentive clasp arm bearing compared to those RPI thermoelastic retentive clasp arm was detected, this difference was statistically insignificant - Insignificant increase in measured pocket depth was detected in all patients of the two groups. - Minimal insignificant increase in measured pocket depth for abutments bearing thermoelastic retainers clasps compared to those bearing cast RPI clasps during the follow up period. From the obtained results from the study it could be concluded that Thermoelastic clasp arm is suitable alternative to cast retentive arm Long term clinical study and patients satisfaction is needed for further assessment.