THE RELATIONSHIP OF DENTAL CALCULUS TO CARIES, GINGIVITIS, AND SELECTED SALIVARY FACTORS IN 11-YEAR-OLD TO 13-YEAR-OLD CHILDREN IN CHIANG-MAI, THAILAND

THAI CHILDREN HAVE BEEN SHOWN TO ACCUMULATE large amounts of dental ca lculus. The purpose of this study was to examine the relationship of c alculus to caries and gingivitis, and salivary conditions which may co ntribute to calculus accumulation. Four-hundred and thirty-nine (439) children from LU schools in Chiang Mai were selected for this study. T he children were given oral examinations io determine calculus index ( CI); decayed, missing, and filled surfaces (DMFS); decayed, missing, a nd filled teeth (DMFT); gingival index (GI); and plaque index (PI). Ch ildren with mean CI scores greater than or equal to 1 (206) were assig ned to the calculus group; the 233 children with mean CI scores of <1 to the noncalculus group. Saliva, was collected from 60 randomly selec ted children in each group. Unstimulated and stimulated whole saliva a nd stimulated parotid saliva were assessed for flow rate, pH, and buff er capacity using 2 methods. Results showed that calculus status was n ot significantly associated with caries, but that there was a high ass ociation between gingivitis and plaque status with calculus accumulati on (P < 0.001). There were no significant differences in saliva flow r ate, pH, or buffer capacity between calculus and noncalculus groups. T he lack of association between calculus status and caries indicated th ese 2 conditions have different etiologies and suggests the importance of plaque and calculus prevention programs, in addition to caries con trol efforts, to maintain oral health of Thai children.