Effect of Cigarette Smoking and Body Mass Index on Salivary Calcium and Phosphate Concentration in Chronic Periodontitis Patients

Abstract

Background: Periodontitis is a multi-factorial disease related to the formation of dental plaque. Saliva composition plays a role in plaque formation and in the development of periodontal disease. Objectives: This study was designed to compare the salivary concentrations of calcium and phosphate between patients with chronic periodontitis (CP) and healthy individuals and to assess the effect of smoking status in this regard. Patients and Methods: This case control study was conducted on 50 healthy subjects and 56 patients with CP. The two groups were matched in terms of age, sex, and smoking status. After obtaining written informed consents from the subjects, periodontal parameters such as calculus index (CI), plaque index (PI), bleeding index (BI) and clinical attachment loss (CAL) as well as body mass index (BMI) were calculated and recorded. Non-stimulated saliva was collected by the spitting method, and the concentration of calcium and phosphate was measured by spectrophotometry. Data were analyzed using independent t-test. Pearson correlation was utilized to correlate the periodontal parameters with the salivary concentrations of calcium and phosphate in the CP group. Confidence interval and P value were set to 95% and ≤ 0.05, respectively. Results: The mean concentration of phosphate in the saliva of CP patients was significantly higher than that in healthy individuals (P = 0.008). No significant difference was found between the two groups in the mean concentration of calcium in the saliva (P = 0.145). The mean concentrations of calcium and phosphate were not significantly different between non-smoker CP patients and healthy subjects. However, the concentrations of calcium and phosphate in the saliva of smoker CP patients were significantly lower and higher, respectively, than the corresponding values in the healthy smoker group (P = 0.016 and P = 0.037, respectively). In subjects with BMI < 25, the mean concentration of salivary phosphate in CP patients was significantly higher than that in healthy individuals (P = 0.005). Among the periodontal parameters, only CI had a significant correlation with the concentration of phosphate in the saliva of patients with CP (P = 0.029). Conclusions: Cigarette smoking and BMI are two main confounding factors affecting the correlation of calcium and phosphate concentrations in the saliva and periodontal status.