Association of the New Periodontitis Classification with the Incidence Rate of Cause-specific Tooth Loss during Maintenance

Abstract

Patients with periodontitis could lose teeth for reasons other than periodontal disease. The aim of this study was to assess the association of the use of the new periodontitis classification with changes in the incidence rate of tooth loss due to periodontitis (TLPD) and tooth loss due to other reasons (TLOR) during the maintenance phase. A total of 328 patients (mean age: 52.1 years) treated for periodontitis at a dental clinic who were followed up for periods ranging from 60 to 143 months were retrospectively categorized according to the new 2018 classification of periodontitis at the baseline. The association of the new classification of periodontitis with the cumulative incidence rate for tooth loss (TL) during the maintenance phase was explored using 1-KM survival analysis and Gray analysis. The cause-specific mortality was examined by regression analysis using a Cox proportional hazards model. No tooth loss was found in stage I or grade A patients during the maintenance phase. The 97-month cumulative incidence rates of TLPD were 6.6%, 3.4%, and 2.8% for stage IV, grade C, and generalized patients, respectively. Statistically significant differences were observed among stages and grades, and between extents. The multivariate Cox regression analysis demonstrated that the new periodontitis classification was associated with the cumulative incidence rate of TL and TLPD, but not of TLOR, although TLOR was associated with the number of teeth at the start of maintenance. The new periodontitis classification has been shown to be associated with TL and TLPD, but not with TLOR during the maintenance phase.