Dental Plaque and Calculus: Risk Indicators for Their Formation

Abstract

The aim of this study was to determine the levels of plaque and subgingival calculus accumulation and to evaluate their correlations with periodontal disease, as well as to evaluate the correlations with race, age, and gender in an attempt to identify risk indicators for plaque and calculus formation. A total of 508 adults 25-73 years of age was examined, and plaque assessment, gingival bleeding assessment, probing pocket depth, and attachment levels were determined. The mean percent visible plaque was 73.5% (range, 8.3-100%), mean percent of bleeding surfaces 38.5% (range, 0-100%), and the mean percent teeth with subgingival calculus 39.6% (range, 0-100%). The mean probing pocket depth in the group was 2.5 ± 0.6 mm (SD), and mean clinical attachment loss was 2.1 ± 1.1 mm. The majority (63%) were classified as having "Moderate" periodontal disease, 7% were "Healthy", and the remaining 30% had "Established" periodontal disease. Plaque and calculus showed statistically significant relationships to the three disease categories (p < 0.001). Multiple step-wise regression analyses on the correlations between plaque and periodontal disease, race, age, and gender resulted in an overall correlation coefficient of r = 0.25 (p < 0.001). Disease status ("Established") contributed most (p = 0.003), followed by race (Blacks; p = 0.015), gender (Males; p = 0.022), and age (55-73 yr; p = 0.022), to the correlation with plaque. For subgingival calculus, the overall correlation coefficient was r = 0.44 (p < 0.001). However, only two of the variables-namely, disease status (p < 0.001) followed by race (p = 0.017)-showed statistically significant correlations. In this population, age, being male, and being Black were risk indicators for supragingival plaque, while race alone was a risk indicator for subgingival calculus. Hence, it is reasonable to test intervention measures which effectively control plaque and subgingival calculus in these target groups to determine their importance in the development of periodontitis.