Radiographic assessment of proximal surface carious lesion progression in Chilean young adults

To investigate the rate and associations of interproximal carious lesion progression.

Retrospective data were analysed from 125 young adults (age range: 18-29 years) with repeated bitewing radiographs collected over a 6-year period. Participants were submitted to different protocols of radiographic examination frequency. Transitions from outer enamel to outer dentine (OE-to-OD) and from outer dentine to dentine (OD-to-D) were selected because of their clinical relevance. Factors associated with each transition were assessed in Cox regression models.

One hundred seven (85.6%) and 52 (41.6%) participants experienced OE-to-OD and OD-to-D transitions, respectively. In addition, 16.8% of 537 eligible surfaces progressed from OE-to-OD whereas 59.4% of 128 eligible surfaces progressed from OD-to-D. Incidence rates were 6.6 and 44.1 per 100 tooth surface-years, respectively. Mean survival time for OE-to-OD transition was 6.4 years (95% confidence interval: 6.0-6.9) and the median survival time for OD-to-D transition was 1.6 years (95%CI: 1.3-1.7). In adjusted Cox regression models, location in the lower jaw (hazard ratio: 0.34; 95% CI: 0.21-0.57) was inversely associated with OE-to-OD progression. In addition, proximal DMFS at baseline (HR: 0.93; 95%CI: 0.87-0.99) and location in the lower jaw (HR: 0.51; 95%CI: 0.26-0.99) were inversely associated with OD-to-D progression.

This group of Chilean young adults has a high progression rate of proximal caries lesions. Location of the caries lesion and proximal DMFS were the only factors associated with caries progression.