Calculus scoring

Table 1. Calculus scoring systems employed in Unilever-sponsored clinical trials... 

Of key importance, as noted earlier, plaque is likely to be a zone relatively free of crystal growth inhibitors. This is because of the presence of numerous enzymes able to break down both salivary pyrophosphate and salivary proteins. Watanabe et al. [123] observed a significant correlation between supra-gingival calculus scores and protein activity in saliva. They demonstrated that the protease originated in plaque bacteria [124, 125] and that the enzyme was able to nullify the inhibiting effect of salivary protein on calcium phosphate precipitation in vitro [125],... 

For the current data analysis, the presence of calculus was denoted by scores of 1 or 2 for the type I index and 3 or 4 for the type II index. The exception is the Villefranche trial where no 4s and very few 3s were recorded, so that 2 or 3 have been used. ... 

There have been a number of Unilever-sponsored 3-year caries clinical trials during which calculus prevalence was also recorded. Table 1 summarises the variations in the scoring system employed. For the purpose of the present analysis, scores have been combined to produce two subject groups those with calculus and those without calculus. Mean baseline caries and calculus prevalence data from six trials are listed in table 2, whilst corresponding 3-year caries increment data and calculus prevalence at the end of each trial are listed in table 3. 

The baseline data of table 2 show that caries prevalence is significantly lower in calculus-prone subjects than in calculus-free subjects in 5 of the 6 studies (average difference = 16%). The caries difference varies from one study to another, possibly because of differences in the clinicians interpretation of the scoring system, but overall the inverse relationship between calculus and caries is clear. 

By the age of ten, the mathematics prodigy was scoring better on college-level calculus exams than the university students. 

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