Clinical performance and prosthetic outcomes in reinforced implant-supported overdentures: A systematic review.

STATEMENT OF PROBLEM: Prosthetic reinforcement and attachment selection are intended to improve the mechanical stability and serviceability of implant-supported overdentures; however, their influence on survival and maintenance outcomes has not been consistently quantified. PURPOSE: The purpose of this systematic review was to evaluate the effect of reinforcement strategies and attachment systems on survival, mechanical complications, and maintenance outcomes of reinforced implant-supported overdentures. MATERIAL AND METHODS: The MEDLINE (PubMed), Scopus, and Ovid databases were searched for English-language clinical studies published from 2010 through 2025. Randomized controlled trials and nonrandomized clinical studies reporting reinforced implant overdentures were included. Study selection and data extraction were performed independently by 2 reviewers. Risk of bias was assessed using RoB 2.0 for randomized trials and ROBINS-I for nonrandomized studies. Because of heterogeneity in design and outcome reporting, meta-analysis was not performed, and results were synthesized descriptively. RESULTS: Twenty-nine studies were included (3 randomized trials and 26 observational investigations). The sample sizes ranged from single-patient reports to cohorts exceeding 200 participants, with follow-up periods between 6 and 168 months. Stud attachments (LOCATOR or ball), bar-retained frameworks, and telescopic systems were the most frequently evaluated. Implant survival exceeded 95% in most studies. Prosthesis survival was high; however, maintenance events were common, including attachment wear, insert replacement, clip activation, relining, and denture base or framework repair. Bar-reinforced overdentures demonstrated fewer base fractures but greater hygiene-related maintenance, whereas stud attachments showed higher component replacement rates. Substantial clinical and methodological heterogeneity and predominantly observational designs limited comparative analysis. CONCLUSIONS: Reinforced implant overdentures show high survival but require ongoing maintenance. Attachment design and reinforcement type primarily influence complication profiles rather than survival. Current evidence is mainly observational, and high-quality randomized trials with standardized outcomes are needed.