Calcium concentrations in dental plaque of patients with juvenile and adult periodontitis.

Calcium concentrations in plaque of patients with juvenile (JP) and adult (AP) periodontitis were compared. These calcium concentrations in JP patients were significantly (P less than 0.01) lower than in AP patients. Because JP patients are not intense calculus-formers, the finding that they have low calcium concentrations in plaque agrees with the authors' previous suggestion that calculus formation is a marker of high calcium concentrations in plaque. JP patients have good caries resistance in general, as was the case in this study. The finding that they have low calcium concentrations in plaque conflicts with the view that caries-resistant dentitions are usually associated with high concentrations of calcium in plaque.