Dietary models for root caries.

A stepwise multiple logistic regression was computed to assess which of the nutritional variables differentiate the healthy and diseased group of participants in the Forsyth Specialized Caries Center (n = 275). Variables considered as candidates for the model included the consumption per week of sugars, starch, cheese, fruits and fruit juices, noncariogenic foods, and dairy products. Two variables--sugars and cheese--were statistically significant by the stepwise procedure. Increased intake of sugar was associated with being in the root caries group, whereas high intake of cheese was negatively associated with root caries. Thus, cheese seems to have a protective effect after sugar intake is controlled for. Odds ratios were computed to quantify the influence of the variables. An increase of two exposures of sugar per day corresponded with an odds ratio of 1.26. The odds ratio continues to increase with sugar intake so that an increase to five exposures per day gives an odds ratio of 1.79. This model is consistent with past in vitro studies suggesting that cheese protects against caries formation when sugar intake is controlled for and that increasing frequency of sugar intake increases the odds of root caries.