THE SITE-SPECIFICITY OF SUPRAGINGIVAL CALCULUS DEPOSITION ON THE LINGUAL SURFACES OF THE 6 PERMANENT LOWER ANTERIOR TEETH IN HUMANS AND THEEFFECTS OF AGE, SEX, GUM-CHEWING HABITS, AND THE TIME SINCE THE LAST PROPHYLAXIS ON CALCULUS SCORES

The hypotheses to be tested were: (i) that chewing sugar-free gum freq uently and for long periods would be associated with higher amounts of supragingival calculus, and (ii) that there would be no site-specific ity of calculus deposition on the lingual surfaces of the 6 lower ante rior teeth. Subjects, 436 in Glasgow and 191 in Winnipeg, were scored for calculus at mesial, lingual, and distal sites on the lingual surfa ce of each of the 6 lower anterior teeth, by the Volpe-Manhold method. They also answered questions on the time since the last prophylaxis, the frequency of gum chewing, the type of gum chewed, and the length o f a typical gum-chewing episode. A subset (233) of the Glasgow subject s were scaled and re-scored for calculus 3 months later. When the data for the logarithmic transformations of the initial calculus scores we re subjected to stepwise multiple-regression analysis, the only factor which correlated significantly with initial calculus scores in both c ities was the time since the last prophylaxis. In the Glasgow subjects scored 3 months after a prophylaxis, there was a negative correlation between chewing sugar-free gum and calculus scores, whereas in the Wi nnipeg subjects, age and the chewing of sucrose-containing and sugar-f ree gum were positively correlated with calculus scores. Thus, the res ults were contradictory with respect to the first-tested hypothesis. T he calculus distribution patterns were very similar in the subset of G lasgow subjects and the Winnipeg subjects, with the amounts on the lat eral incisors and canines averaging 70.2% and 44.5%, respectively, of those on the central incisors. Thus, the second hypothesis was disprov ed.