Diagnostic accuracy of 870-nm spectral-domain OCT with enhanced depth imaging for the detection of caries beneath ceramics

Abstract

ObjectivesTo evaluate the diagnostic accuracy of optical coherence tomography (OCT) for the non-invasive detection of caries adjacent to ceramic materials. MethodsDisks made from five ceramic materials (hybrid ceramic, feldspathic ceramic, zirconia-reinforced lithium silicate, lithium disilicate, and high-translucent zirconia) were ground to the recommended material thickness for single crown restorations and laminated with a 100 μm thick layer of one of three adhesive cements. The disks were fixed to extracted human molars with or without carious lesions of one of three standardized sizes. A total of 240 stacks of cross-sectional scans obtained using an 870-nm SD-OCT with enhanced depth imaging (EDI) were presented to five raters. Diagnostic accuracy was determined by rating the teeth beneath the cemented material as carious or healthy. ResultsCarious samples were distinguished from sound teeth with high diagnostic accuracy, even for early stage caries. Sensitivity (SE) and specificity (SP) pooled over all raters and all materials were 0.9 and 0.97, respectively. When analyzing the effect of the ceramic and cement materials on detection rates, high SE and SP values of >0.96 and >0.91, respectively, were recorded for lithium disilicate, zirconia-reinforced lithium silicate, and high-translucent zirconia irrespective of the cement type. For hybrid and feldspathic ceramics, the cement material was found to have a significant effect on caries detection. ConclusionsGiven its high diagnostic accuracy, 870-nm SD-OCT with EDI might be useful for the detection of caries beneath restorative materials. The effect of the prescribed ceramic and cement material on optical penetration depth is substantial.