A 30-year retrospective cohort outcome study of periodontal treatment of stages III and IV patients in a private practice.

AIM: Tooth loss studies show that periodontal treatment is effective. However, it is not known whether these results can be projected into a lifetime of treatment. The aim of the study was to study all patients with stages III/IV of periodontitis over 30 years in a private practice. MATERIALS AND METHODS: All patients referred between 1986 and 1990 were monitored for 30 years for tooth loss and prognostic factors. All dropouts were accounted for. RESULTS: In all, 386 patients were followed, of whom 283 patients dropped out, leaving 103 patients (67 females and 36 males, average age 40.1 years) monitored over 30 years. Tooth loss was stable until 16 years, when the population was divided into groups of low (n = 65), moderate (n = 18) and high (n = 20) tooth loss, losing 1.05 (SD 1.27), 4.83 (SD 0.96) and 11.90 (SD 4.25) teeth, respectively. The strongest prognostic factors were first-degree relatives with periodontitis, periodontal treatment before the age of 35 years, diabetes and patients with teeth with initial hopeless prognosis. CONCLUSION: The majority of patients with stages III and IV periodontitis could be successfully treated with conventional periodontal treatment over a period of 30 years. The findings suggest that retrospective studies with shorter observation times cannot automatically be projected onto the outcome of a lifetime of periodontal treatment.