Attachment versus Clasp retained Removable Partial Dentures –A Randomized Controlled Clinical Trial

Purpose: to compare two retainer designs for free end removable partial dentures (RPDs) by measuring the patient satisfaction, abutment tooth survival, bone height loss and pocket depth.
Materials and Methods: Group 1: Fourteen patients receiving attachment-retained RPDs while group 2: Fourteen patients receiving clasp-retained RPDs. The assessment included patient satisfaction, survival of the terminal abutments, bone height loss and pocket depth. All patients were evaluated clinically and radiographically at the time of RPD insertion, twelve months and 24 months thereafter. Mann Whitney U test for independent samples was used for comparison of
% change of patient satisfaction. Wilcoxon signed rank test for paired (matched) samples was used within group comparison of patient satisfaction before and after treatment. Survival analysis was done using Kaplan Meier statistics. For bone height, independent t-test was used and student’s
t- test was used for pocket depth comparison.
Results: There was a significant difference before and after treatment scores in Oral Health Impact Profile-14(OHIP-14), Orofacial Esthetic Scale (OES) and Chewing Function Questionnaire (CFQ) questionnaires in the clasp retained RPD group with P value = (0.001, 0.001 and 0.003) respectively. Regarding the attachment retained RPD group, there was a significant difference before and after treatment scores with P value = 0.001 for the three questionnaires. Within group comparison it was found that there was a significant difference in OHIP-14 (P= 0.002) and OES (P<0.001) while there was no significant difference in CFQ between both groups (P=0.191). There was no statistically significant difference between both groups in terminal abutment survival (P=0.149) and percent change of the mean probing pocket depth from baseline to 24 months (P=0.05). However, regarding the effect of time on bone height change percentage for each group, a significant difference was found between groups at baseline-twenty-four month’s interval (P-value < 0.05).
Conclusion: Within the limitations of the present study, all patients have shown improvement in OHRQoL, esthetics and chewing function after treatment with RPDs with better results in the attachment retained RPD. However, regarding the terminal abutment survival, mean probing pocket depth and bone height change, clinically significant better results were revealed in clasp-retained RPD compared to attachment-retained RPDs.