Association of Salivary Zinc Levels to Dental Caries and Body Mass Index. A Comparative Study

Background and objectives: Role of salivary zinc to dental caries and body weight has not been studied extensively in children. The aim of the present study was to evaluate the relationship between salivary zinc and caries in overweight/obese Indian children. Study design: One hundred and sixty children aged 8-12 years of both genders were divided into two groups of eighty each based on their body mass index into normal weight and overweight/obese. Each child was assessed for their caries experience in primary and permanent dentition. Unstimulated salivary samples were collected from each child to estimate zinc levels by atomic absorption spectrophotometer. Data was subjected to statistical analysis. Results: The mean caries score among the overweight/obese children was 2.2 +/- 3.9 and 0.7 +/- 1.5 in the primary and permanent dentition respectively compared to the 2.0 +/- 2.6 and 0.2 +/- 0.5 respectively among normal weight children. Mean salivary zinc levels in overweight/obese children were 0.36 +/- 0.27 ppm compared to normal weight children of 0.81 +/- 0.46 ppm. Conclusion: Overweight/obese children demonstrated significantly lower salivary zinc levels and higher caries experience in permanent dentition. Salivary zinc levels showed a positive but weak association to caries in permanent dentition in both groups. Salivary zinc levels showed a negative non-significant correlation to caries in primary dentition among the children with higher BMI.