Unrestored dentin caries and deep dentin restorations in Swedish adolescents

The objectives of this longitudinal study were to assess: (a) the prevalence of unrestored dentin caries among 15-year-olds, (b) the proportion of these lesions that had progressed to deep dentin lesions (inner half of dentin) since the immediately preceding examination at the age of 14 and (c) the frequency of deep restorations (extending into the inner half of the dentin). The sample consisted of all 15-year-olds (n = 2,487) born in 1990 and included in the Public Dental Service in Malmo, Sweden. Bitewing radiographs taken during 2005-2007 and the immediately preceding radiographs were analysed and scored by two examiners. The main radiographic scores were: sound; radiolucency in the outer or inner half of dentin; restored surface. The results showed that 22% of the individuals had 1 or more dentin lesions left unrestored from the time of the examination at the age of 14 until the next recall examination at the age of 15. During the observation period (median time 1.2 years), 9% of the unrestored outer dentin lesions progressed to deep dentin lesions. The majority of these (93%) were in molars. One or more deep restorations were found in 22% of the 15-year-olds; the majority involved occlusal surfaces of first molars. In conclusion, unrestored dentin lesions were common in 15-year-olds. Progression to deep dentin lesions occurred in 9% of these lesions and was most common in first molars. Occlusal surfaces of first molars had the highest frequency of deep restorations.