Predictors of tooth loss during long-term periodontal maintenance: An updated systematic review

Aim: To evaluate the risk factors / predictors of tooth loss in patients with periodontitis who underwent periodontal therapy and long-term periodontal maintenance (PM). Material and Methods: PubMed, CENTRAL, EMBASE, Web of Science, LILACS and Scholar were searched up to and including September 2020. Studies limited to periodontitis patients who underwent active periodontal therapy (APT) and followed a regular PM programme with 5 years follow-up minimum were eligible for inclusion in this review. Studies were included if they reported data on tooth loss during PM. Random effects meta-analyses of number of tooth loss per patient per year were conducted. Results: Thirty-six papers regarding thirty-three studies were included in this review, with three prospective 30 retrospective trials. Subgroup meta-analysis showed no differences between prospective and retrospective studies, with an average of 0.1 tooth loss per year per patient (p < 0.001). Maxillary and molar teeth were more susceptible to be extracted during long-term PM. Baseline characteristics (smoking, diabetes mellitus, cardiovascular disease, being male and teeth with furcation lesions) showed no significance as predictor of tooth loss through meta-regression. The percentage of tooth loss due to periodontal reasons ranged from 0.45% to 14.4%. The individual outcomes in each study evidenced different patient-related factors (age and smoking) and tooth-related factors (i.e. tooth type and location) were associated with tooth loss during PM. Conclusion: The majority of patients undergoing long-term PM have not lost teeth. On average, long-term PM effectively causes the loss of 1 tooth per patient every 10 years. Additional prospective trials may confirm these results.