The influence of the interaction between staging, grading and extent on tooth loss due to periodontitis

Aim To assess the ability of two-way interactions between baseline stage, grade and extent to predict tooth loss due periodontitis (TLP) over a long-term follow-up period. Materials Methods Patients treated for periodontal disease with complete medical history, chart, full mouth radiographs minimum ?10 years were recruited. Supportive therapy (SPT) visits recorded during entire categorized according their extent. The absolute survival at 10-, 20-, 30-year was calculated TLP. Kaplan–Meier curves plotted tooth-level multilevel Cox regression frailty models constructed in order association among predictive variables TLP by taking into account hierarchical patient-teeth structure. Results 442 patients (11,125 teeth) mean 23 met inclusion criteria included this study. most prevalent diagnosis stage III B (30.3%), followed II (23.5%). Among parameters analysed, found be best predictors Statistically significant differences observed only severe (stage IV or C). analysis demonstrated that higher concomitant staging grading developed greater Conclusions Higher corresponded risk generalized became predictor C disease.