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

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.

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.

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.

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.

This study was registered in the UMIN Clinical Trials Registry (UMIN000056738).