Effectiveness of Cleaning Methods for Resilient Denture Liners: A Three-Period Randomized Crossover Trial

Abstract

Objective: Several studies have demonstrated that insufficient denture hygiene constitutes a significant risk factor for aspiration pneumonia. While various cleaning protocols have been proposed for conventional hard denture base materials, there remains a notable paucity of research specifically addressing effective cleaning strategies for resilient denture liners (RDLs). This study aimed to evaluate the efficacy of three denture cleaning methods—mechanical, chemical, and dual (combined mechanical and chemical)—for removing microbial biofilms from different denture-liner materials using a randomized crossover clinical trial. Materials and Methods: This three-period randomized crossover clinical trial included edentulous patients wearing maxillary complete dentures embedded with specimens of a hard-resin liner and silicone-based and acrylic-based RDLs. All liners were fabricated directly in the patient's mouth. Participants performed the three cleaning interventions for 2 weeks each. Swabs from the relined denture surfaces were cultured in phosphate-buffered saline, and the colony-forming units (CFUs) were counted. The influence of each cleaning method on the CFU count was determined. Results: The dual-cleaning method demonstrated a significant reduction in CFU count compared to mechanical cleaning, but only for the acrylic-based RDL. No significant differences were observed between the cleaning methods for the silicone-based RDL and hard-resin liner. The CFU count was the highest for silicone-based RDLs, followed by that for acrylic-based RDLs, and hard-resin liners. Conclusion: The dual method comprising mechanical and chemical cleaning was the most effective cleaning strategy for relined dentures, although the advantage was limited to acrylic-based RDL. Trial Registration: This study was registered in the UMIN Clinical Trials Registry (UMIN000056738).