RESUMO
Objective Quantitative analysis of optical coherence tomography (OCT) images of naturally occurred early enamel caries was performed to find quantitative parameter indicator for detecting early caries by OCT.Methods Three human premolars with enamel natural caries in D0,D1,and D2 stages were selected respectively and scanned by OCT.The ratios of the average gray value of the caries region (object region) and sound region (background region),namely,the object-background contrast (OBC) were calculated in OCT images and selected as the quantitative parameters to analyze the OBC trend of different degree of enamel caries.Results Within the fixed depth,the OBC value showed a trend of first increase and then decrease with the severity of dental caries,indicating that OBC value increased with the severity of dental caries from normal to D1 stage,and then decreased from D1 to D2 stage.Conclusion The OBC value can be used as a new quantitative indicator for OCT to estimate the severity of naturally occurred early caries.