ABSTRACT Aim To investigate whether the number of residual probing pocket depths (PPDs) ≥ 5 mm predicts periodontitis progression in non‐smoking patients undergoing supportive periodontal care (SPC). Materials and Methods This retrospective study included 121 patients (3028 teeth), with Stage III/IV, Grade B/C periodontitis, who completed active periodontal therapy and were enrolled in SPC. Multivariable logistic regression with inverse probability censoring weighting assessed the association between the number of residual sites with PPD ≥ 5 mm at the start of SPC and disease progression at 1‐year and 5‐year intervals. Receiver operating characteristic (ROC) curve analysis was used to identify optimal thresholds for predicting progression. Results Each additional site with PPD ≥ 5 mm at the start of SPC was associated with higher odds of disease progression (≥ 2 mm PPD increase at any site) after 1 year (adjusted OR: 1.15; 95% CI: 1.05–1.29). For periodontal tooth loss, each additional PPD ≥ 5 mm site increased the odds by 11% over 5 years. ROC analysis suggested that ≥ 6 residual sites provided the best discrimination for predicting 1‐year PD progression (AUC: 0.73). Conclusion Six or more residual PPDs ≥ 5 mm at SPC were associated with short‐term disease progression, although the performance was modest.
Tay et al. (2026) studied this question.