Comparison of the efficacy of periodontal prognostic systems in predicting tooth loss

Aim The aim of this analysis was to assess how different tooth-prognosis systems could predict tooth loss in a cohort of periodontitis patients followed up prospectively during supportive periodontal care (SPC). Materials and Methods Clinical and radiographic data of 97 patients undergoing regular SPC for 5 years were used to assign tooth prognosis using four different systems (McGuire & Nunn, 1996; Kwok & Caton, 2007; Graetz et al., 2011; Nibali et al., 2017). Three independent examiners assigned tooth prognosis using all four systems, following a calibration exercise. The association between prognostic categories and tooth loss was tested for each prognostic system separately and across prognostic systems. Results All four systems showed good reproducibility and could identify teeth at higher risk of being lost during 5 years of SPC; the risk of tooth loss increased with the worsening of tooth-prognosis category (p < .0001). Although specificity and negative predictive values were good, low sensitivity and positive predictive values were detected for all systems. Conclusions Previously published periodontal prognostic systems exhibited good reproducibility and predictive ability for tooth retention. However, low sensitivity was detected, with several teeth in the worst prognosis category being retained at 5 years. Some modifications in the number of categories and their definitions are suggested.