Assessment of denture plaque pH in subjects with and without denture stomatitis

To evaluate the "resting" pH and induced pH changes in denture plaque, soft deposits were collected from the fitting surface of the denture, pooled and suspended in water. Plaque pH was determined with microelectrode equipment before and after mouth rinsing with a sucrose solution. A characteristic level in the "resting" pH of denture plaque was found in most of 12 subjects tested. pH values below the baseline level were recorded for more than 2 h after a rinse. The pH depressions were more pronounced in maxillary than in mandibular plaque. Further, the pH minima tended to be lower in subjects with denture stomatitis than in controls. No clear relationship could be established between the "resting" pH and the concentration of Candida hyphae in denture smears or palatal inflammation.