Tooth loss related risk factors and oral microbiota changes in older adults: a cross-sectional study

Objectives This study aimed to analyze the risk factors of tooth loss in the elderly, and to compare the structure and composition of the salivary microbiota between the low residual tooth group and the high residual tooth group, providing theoretical basis for the development of professional and effective preventive and management strategies to improve tooth loss in the elderly. Materials and methods A sexual cross-sectional study was conducted in 310 elderly people over 60 years old. Through clinical examination and questionnaire survey, the risk factors of tooth loss were collected. Monomial and polynomial logistic regression models were used to estimate the data. Non-irritant saliva samples were collected from people in low residual tooth group and high residual tooth group (n = 25/each group) for 16S rRNA sequencing analysis. Results 310 elderly people were categorized into two groups based on their residual teeth count: low residual teeth group (n = 87) and high residual teeth group (n = 223). Tooth loss in the elderly is closely related to age, root caries, frequency of eating dessert and candies, toothpick use, self-rated oral health, and frailty according to the multifactorial analysis. In terms of microbial composition, the proportion of Porphyromonas , Treponema , Asticcacaulis , Filifactor and Prevotella in the low residual tooth group were significantly lower than that in the high residual tooth group. Conclusion Tooth loss is closely related to the aging, poor living habits, and poor oral and physical conditions of the elderly. The proportion of pathogenic bacteria in the elderly population with more tooth is higher. Clinical relevance This study provides some risk factors that can be directly assessed through clinical examination and chairside questionnaires, and provides guidance for subsequent laboratory testing of the microbiota composition of patients' saliva, which is conducive to timely knowledge popularization and long-term help for elderly patients.