Objective: In a 10-year prospective study we analyzed (i) the intra-oral pattern of and (ii) potential risk factors for tooth and periodontal bone loss in 50-year-old individuals.
Methods: A randomized subject sample of 50-year-old inhabitants in the County of Varmland, Sweden, was examined at baseline and after 10 years. Data from full-mouth clinical and radiographic examinations and questionnaire surveys of 309 (72%) of the individuals who were dentate at baseline were available for analysis. Non-parametric tests and binary logistic multiple regression models were used for statistical analysis of the data.
Results: 4.1% of the 7,101 teeth present at baseline, distributed among 39% of the subjects, were lost during the 10-year interval. The incidence of tooth loss was highest among mandibular molars (7.5%) and lowest among canines (1.8%). The relative risk (RR) for tooth loss for endodontically compromised teeth was 4.1 and for furcation-involved molars 2.4-6.5, depending on tooth position. Logistic regression analysis identified baseline alveolar bone level (ABL), endodontic conditions, CPITN score (Community Periodontal Index of Treatment Needs), tooth position, caries, and educational level as risk factors for tooth loss. The overall mean 10-year ABL change was -0.54 mm (S.E. 0.01). On a tooth level the ABL change varied between -0.35 mm (mandibular molars) and -0.79 mm (mandibular incisors). Smokers experienced a greater (20-131% depending on tooth type) mean bone loss than non-smokers. The logistic regression model revealed that tooth position, smoking, and probing pocket depth > or =4 mm were risk factors for bone loss of >1 mm. No pertinent differences were observed with respect to risk factors for ABL change in the subgroup of non-smokers compared to the results of the analysis based on the entire subject sample.
Conclusion: Tooth loss was more common in the molar than in the anterior tooth regions, while periodontal bone loss had a random distribution in the dentition. The predominant risk factors identified with regard to further radiographic bone loss were "probing pocket depth > or =6 mm" and "smoking".