Deep carious lesions and other consequences of caries among 18-year-olds at Public Dental Health Service in Northern Norway: A cross-sectional age cohort study.

Abstract Objectives. To document deep carious lesions and other consequences of caries (DCL-CC) in molars of 18-year olds leaving the free-of-charge Public Dental Health Service (PDHS). To explore the association between background factors and DCL-CC. Materials and methods. The final study sample (n = 1876) comprised 95% of individuals born in 1993 and registered in the PDHS in Troms County, Northern Norway. The most recent digital bitewing radiographs of each subject were examined for DCL-CC (deep untreated carious lesions, deep restorations, root canal obturations or extractions due to caries). Inter- and intra-observer kappa scores were 0.62 and 0.87, respectively. Information on background factors (gender, clinic location, history of medical problems, bitewing examination interval, DMFT score and planned recalls) were retrieved from dental records. Results. About one-quarter of subjects (488) had at least one molar with DCL-CC. There were 848 molars in total with DCL-CC; the majority were deep restorations (70%), but 4% were deep untreated carious lesions. More than a quarter of DCL-CC were either root canal obturations (14%) or extractions (12%). Multivariable logistic regression analyses showed that a 1-unit increase in DMFT score was associated with deep untreated carious lesions and extractions due to caries. There was no association between urban/rural clinic location, which indicated socio-economic status, and either DMFT score or DCL-CC. Conclusions. Despite the existence of a free-of-charge dental service, more than one-quarter of the subjects in the present study had at least one molar with DCL-CC.