Objective: This study aimed to investigate the association between number of natural teeth and prevalence of root caries.
Design: A cross-sectional design was adopted. A stratified multi-stage purposive sampling method was used to select a wide range of elderly people from all social classes, educational levels and sexes. Data was collected through interviews and clinical examinations.
Setting: Urban area in Chiang Mai-Thailand.
Participants: 549 elderly dentate aged 60-74 years.
Main outcome measures: Teeth with decay and filled roots (DF-T).
Results: The prevalence of root caries was 18.2% with a mean DF-T of 0.58 (S.D. 2.02). Results of multiple logistic regression showed that number of teeth, DMF-S scores, sex, and socio economic factors were statistically significantly associated with root caries (P < 0.05). Adjusted odds ratios demonstrated a 14% increase in the chance of having root caries when the number of teeth increased one unit. Similarly, a 3% increase was observed for each unit increase in the DMF-S scores (p < 0.001). Being male, having more than four years of education and earning more than 1500 baht/month increased the chances of root caries by 76%, 139% and 85% respectively (p < 0.001). Recession and age were not statistically significantly associated with root caries.
Conclusions: Having more teeth, higher DMF-S scores, earning more than 1500 baht/month, having more than 4 years of education and being male increased the likelihood of having root caries.