Factors related to the quantity of subgingival calculus in proximal root surfaces

. The aim of this study was to determine the association between the quantity of subgingival calculus and the following factors: type and severity of periodontal disease, age, gender and tobacco consumption. A sample of 622 periodontal patients was studied. The radiographically detectable subgingival calculus in proximal root surfaces was recorded in periapical radiographs, considering the number of surfaces without calculus and the number of surfaces exhibiting deposits equal or greater than 1 mm. The association between the subgingival calculus and the factors under study was analyzed by distinct non‐parametric tests. A statistically significant association was found between the absence/presence of subgingival calculus and the type and severity of periodontal disease (p≤0.001), tobacco consumption (p=0.0049) and age (p≤0.001). The quantity of radiographicallydetectable subgingival calculus increased with increasing age and severity of the disease. However, the reverse association was found in smokers, which presented more surfaces free of calculus (p=0.0377) and less surfaces exhibiting deposits equal or greater than 1 mm. The amount of subgingival calculus decreased as the quantity of tobacco consumed increased (p=0.0129), and such differences were more significant in those smoker patients with severe periodontitis (p=0.0065). An explanation is presented to justify these latter findings, since most literature supports that the presence of calculus is higher in smokers. According to the results of this study, more radiographically‐detectable subgingival calculus in proximal root surfaces was found with increasing severity of the disease, with increasing age and with the absence of tobacco consumption.