Non-surgical periodontal therapy and tooth loss. A cohort study

BACKGROUND: No reliable evidence is available regarding the effect of periodontal therapy on major disease endpoints such as tooth loss, edentulism, or quality of life. The primary objective of this study was to assess the association between tooth loss and the non-surgical periodontal treatment history of 1,021 members of the Kaiser Permanente Dental Care Program. METHODS: Tooth loss rates were estimated using Poisson regression models, adjusting for some of the potentially confounding variables such as initial disease severity and extent. RESULTS: Continuous non-surgical therapy (one or more non-surgical procedures performed during 3 successive years), as opposed to no therapy during such a 3-year period, reduced the subsequent tooth mortality rate by 58% (relative rate, 0.42; 95% confidence interval, 0.29-0.61). Intermittent non-surgical therapy reduced the tooth mortality rate by 48% (RR = 0.52; 95% confidence interval, 0.34-0.80). As the number of non-surgical procedures increased, tooth loss rates decreased. CONCLUSIONS: These findings suggest that non-surgical periodontal therapy may be associated with a substantial reduction in tooth mortality. Different study designs and populations are needed to confirm these findings.