Cervical critical dentin in non-carious cervical lesions: Relationship with remaining dentin thickness and...

To define the critical cervical dentin region (CCD), an anatomical region extending from the cervical enamel limit to the occlusal limit of tertiary dentin, in non-carious cervical lesions (NCCLs), to test its association with dentin thickness, and to evaluate the diagnostic performance of CCD- and depth-based predictors for detecting critical remaining dentin thickness (RDT ≤ 1.0 mm; a criterion for placement of restoration).

A total of 139 natural NCCLs from extracted human premolars were analyzed using micro-computed tomography. Lesion depth, lesion height, depth/height ratio, CCD height, and RDT were measured using standardized cross-sectional images. Linear regression assessed the association between lesion depth and RDT. Risk ratios assessed the associations of CCD with the RDT and lesion depth. Diagnostic performance for detecting critical RDT was tested using restoration predictors (maximum lesion depth, probing lesion depth, and CCD involvement), including morphology-guided sensitivity analyses of diagnostic performance.

Each 1-mm increase in lesion depth reduced RDT by 0.637 mm. The CCD showed the highest occurrence of the lowest RDT, critical RDT, and lesion depth. CCD inner-half involvement and probing depth ≥ 1.5 mm predictors showed good performance when lesion height ≤ 2.5 mm, otherwise diagnostic performance varied across tomographic profiles.

The CCD concentrated the lowest RDT. RDT can be detected with probing lesion depth or CCD involvement when height ≤ 2.5 mm, otherwise a tomography would be required.

Restorative need decision can be made using probing depth cutoff 1.5 mm when height ≤ 2.5 mm.