Tooth loss during maintenance following periodontal treatment in a periodontal practice in Norway

Background: Periodontal therapy coupled with careful maintenance has been shown to be effective in maintaining periodontal health; however, a small number of teeth are still lost because of progressive periodontitis. Aim: To investigate factors associated with tooth loss due to periodontal reasons during maintenance following periodontal treatment in patients in a Norwegian specialist periodontal practice. The study also examined how initial prognosis related to actual outcome as measured by periodontal tooth loss. Methods: Hundred consecutive patients (68 females, 32 males) who had comprehensive periodontal treatment and attended for 9.8 (SD: 0.7), range: 9-11 years of maintenance care, were studied. All teeth classified as being lost due to periodontal disease over the period were identified. Results: Only 36 (1.5%) of the 2436 teeth present at baseline were subsequently lost due to periodontal disease. There were 26 patients who lost at least one tooth. Logistic regression analysis showed that tooth loss was significantly related to male gender (p = 0.049; adjusted odds ratio: 2.8; confidence interval (c.i.): 1.0-8.1), older age, i.e. > 60 years (p = 0.012; adjusted odds ratio: 4.0; c.i.: 1.3-12.0) and smoking (p = 0.019; adjusted odds ratio: 4.2; c.i.: 1.4-13.8). The majority 27 (75%) of the teeth lost due to periodontal disease had been assigned an uncertain, poor or hopeless initial prognosis; however, nine teeth (25%) lost had been assigned a good prognosis at baseline. The prognosis for 202 teeth was judged to have worsened over the period of the study. Conclusion: Compliance with maintenance following periodontal treatment was associated with very low levels of tooth loss in a referral practice in rural Norway. Male gender, older age (> 60 years) and smoking were predictors of tooth loss due to progressive periodontitis.