Tooth loss in individuals under periodontal maintenance therapy: 5-year prospective study

Background and objective: Tooth loss (TL), one of the most visible results of the evolution of periodontitis, causes physiological and psychological impacts on a patient's life. This prospective study aimed to evaluate the incidence, underlying reasons and influence of risk predictors for the occurrence of TL in a program of periodontal maintenance therapy (PMT) over 5 years. Methods: The sample comprised 212 individuals diagnosed with chronic moderate-severe periodontitis, who had finished active periodontal treatment, were incorporated in a PMT program. Individuals were divided in to two groups: 96 regular compliers (RC) and 116 irregular compliers (IC). Full-mouth periodontal examination was performed. Social, demographic, behavioral and biological variables of interest were collected at all PMT visits. The effect of risk predictors and confounders for TL, as well as the underlying reasons of TL, were assessed by univariate and multivariate analysis. Results: TL was significantly lower among RC (0.12 teeth lost/year) in comparison to IC (0.36 teeth lost/year; p < 0.01). Individuals that were > 55 years old, males and smokers lost significantly more teeth in both groups (with IC > RC). The number of teeth lost due to periodontal reasons was significantly higher than TL for other reasons in both groups (p < 0.01). The final linear and logistic model for TL included: male gender, smoking, probing depth 4-6 mm in up to 10% of sites and irregular compliance. Conclusion: IC individuals undergoing PMT presented higher rates of TL when compared to RC individuals. Findings demonstrated the influence of irregular compliance and the importance of monitoring other risk predictors for TL such as smoking, male gender and severity of probing depth during PMT.