The Association between Dry Mouth and the Periodontal Status in Older Adults Undergoing Supportive Periodontal Therapy.

Dry mouth is a common oral condition in older adults, which correlates with dehydration, pH changes, and lubrication in the oral cavity, leading to an imbalance among bacterial activities of dental biofilms. However, the role of dry mouth and periodontal status in older adults has remained limited, especially among periodontal individuals who underwent supportive periodontal therapy (SPT). This study aimed to investigate the association between dry mouth and recurrent periodontitis in older adults undergoing SPT.This cross-sectional study included patients who were part of SPT. The factors of interest were collected by interviews, questionnaires, and clinical assessments. Oral moisture measurement, the clinical oral dryness score, unstimulated salivary flow rate (USSFR), and stimulated salivary flow rate (SSFR) were performed. Full mouth periodontal examination was performed and compared with the previous record of periodontal examination to identify a recurrence of periodontitis based on bleeding on probing (BOP), a change in pocket depth, and clinical attachment level. Descriptive analysis, both univariate and multivariate logistic regression, was performed to delineate the association between dry mouth and recurrent periodontitis.A total of 186 participants were recruited and divided into the recurrent periodontitis ( = 37) and the nonrecurrent periodontitis group ( = 149). Baseline demographics, medical and dental history of the two groups were similar. Participants with hyposalivation were greater in the recurrent group (35.1 vs. 16.1%,  = 0.02), and the mean of USSFR is lower than the nonrecurrent periodontitis group (0.38 vs. 0.53 mL/min,  = 0.01). To examine the relationship between various factors affecting the recurrent periodontitis by using multivariate regression analysis, results demonstrated odds ratio (OR) of hyposalivation and percentage of BOP (%BOP) in recurrent periodontitis at 2.63 (95% CI = 1.05-6.58),  = 0.04 and 1.04 (95% CI = 1.02-1.06),  < 0.001 after adjusting for confounding factors.This study supported the hypothesis that hyposalivation is associated with recurrent periodontitis demonstrated by USSFR and %BOP association. Consistent periodontal care, including an examination and guidance on managing dry mouth, has the potential to help older individuals with periodontitis maintaining their dental health.