Material compatibility and antimicrobial activity of consumer products commonly used to clean dentures

Statement of problem. Regular denture cleaning is essential to good oral health, but only limited evidence is available regarding the effects of common cleaning routines. Purpose. The purpose of this in vitro study was to determine the compatibility of denture materials with and the antimicrobial effects of typical cleaning regimens. Material and methods. The evaluated treatments were derived from a study of dental professional recommendations and consumer habits, including denture cleanser tablets, toothpaste, mouthwash, isopropyl alcohol (IPA), household bleach, soap, and vinegar. The material integrity of denture materials, including polymethyl methacrylate (PMMA) and metals, was evaluated by scanning electron microscopy and profilometry after treatment with laboratory regimens simulating 2 years of typical consumer use. Treatments were also evaluated in a microbial kill time assay against a range of oral microorganisms with typical treatment regimens. Results. Alcohol-based mouthwash and IPA damaged the surface of PMMA, and brushing with toothpaste caused scratching and surface material loss. Bleach caused limited damage to PMMA, but corroded CoCr alloy (pitting) and solder (layer formation). Denture tablets caused little damage to any materials apart from the layer formation on silver solder. Vinegar and soap were compatible with all materials. In antimicrobial assays, bleach gave excellent results, and IPA and mouthwash required concentrated dilutions to be effective. Cleanser tablets were effective at 5 minutes treatment time against all organisms. Toothpaste was effective against bacteria but not Candida albicans. Vinegar, soaps, salt, and sodium bicarbonate were microbially ineffective. Conclusions. Bleach was highly antimicrobial but incompatible with metal dental prosthesis components. IPA and mouthwash were antimicrobial but damaged PMMA. Specialist denture cleanser tablets gave a good combination of microbial efficacy and reasonable material compatibility.