The influence of dynamic occlusal interferences on probing depth and attachment level: Results of the Study of Health in Pomerania (SHIP)

Background: The purpose of this study was to investigate potential associations between dynamic occlusal interferences and signs of periodontal disease in posterior teeth based on dental and medical measurements obtained from a population-based sample in the cross-sectional epidemiological study entitled, "Study of Health in Pomerania" (SHIP). Methods: Medical history and dental and sociodemographic parameters of 2,980 representatively selected dentate subjects, 20 to 79 years of age, were collected. The analysis was performed on posterior teeth only using a mixed linear model that considers the clustered structure of the data. The model also was adjusted with respect to known risk factors for periodontal disease. Results: The presence of non-working side contacts only was significantly related to probing depth (P < 0.0001) and attachment loss (P= 0.001). The presence of non-working side contacts and working side contacts on the same tooth was significantly related to increased probing depth (P= 0.004) but not attachment level. The effect magnitude was a mean increase of 0.13 mm for probing depth and 0.14 mm in attach ment loss. Known risk factors for periodontal disease that also showed significant associations with probing depth and attachment loss included male gender, age, smoking, education, and plaque score. Other factors significantly related to probing depth and/or attachment loss were tilted teeth, restored occlusal surfaces versus sound surfaces, elongated teeth, and tooth type (molar versus premolar). Conclusion: The effect of non-working contacts on periodontal disease status was discernible, but weak in terms of magnitude and specificity.