Implant-Supported Removable Partial Dentures: A Randomized Controlled Trial

This randomized crossover study evaluated the clinical outcomes of implant-supported distal-extension removable partial dentures (ISRPDs) compared to conventional removable partial dentures (CRPDs) in terms of masticatory performance and patient satisfaction. Thirty participants with distal extension ridges (Kennedy I/II edentulism) were randomly assigned to two groups(n=15/group) using a 2×2 crossover design: CRPD-ISRPD (transitioning from conventional dentures to implant-supported dentures) and ISRPD-CRPD (reverse sequence). ISRPDs were fabricated by relining the conventional RPD base with autopolymerizing resin to engage attachment abutments, while conversion to CRPD was achieved by replacing abutments with healing abutments. The RPD base was designed with a reserved space at the implant site. Each treatment phase lasted 4 weeks, separated by a 2-week washout period to minimize carryover effects. Masticatory efficiency was assessed spectrophotometrically by measuring the absorbance of supernatants from chewed standardized test food. Occlusal force and contact area were analyzed using the T-scan system. Patient satisfaction was measured using OHIP-14 questionnaire. ISRPDs significantly improved masticatory efficiency (p < 0.05), increased occlusal contact area at distal ridges, and promoted a more balanced occlusal force distribution compared to CRPDs. Patient satisfaction (OHIP-14) was higher with ISRPDs (p < 0.01), particularly regarding retention, comfort and stability. ISRPDs demonstrated enhanced clinical outcomes, providing improved masticatory function and greater patient satisfaction in distal-extension RPD cases.