Correlation between fissure discoloration, Diagnodent measurements, and caries depth: an in vitro study

Abstract

Purpose: This in vitro study was performed to correlate the presence of discoloration on occlusal surfaces with its histological depth and assess its influence on Diagnodent measurements in a group of permanent and primary teeth.

Methods: Ninty-five primary and 95 permanent third molars were randomly selected from a pool of macroscopically intact teeth. One site of the fissure on each occlusal surface was selected and categorized according to its discoloration. Each site was measured 3 times with Diagnodent. The teeth were prepared histologically and evaluated according to their caries extent under a microscope (final magnification x 12.8).

Results: In the group of permanent teeth with dark brown or black discoloration (N=23), 13% showed dentinal caries, 57% were sound or had an initial enamel lesion, and 30% had a deep enamel lesion. In the group of primary teeth with dark brown and black discoloration (N=19), 42% presented dentinal caries, 42% showed deep enamel caries, and 16% had an initial enamel lesion. The difference between permanent and primary teeth was statistically significant (P<.05). Discolored fissures showed higher Diagnodent values than nondiscolored or opaque fissures in both groups (independent of their caries status).

Conclusions: The presence of brown or dark spots on fissures were not useful for the prediction of dentinal caries for permanent teeth. In primary teeth, however, a higher correlation between fissure discoloration and dentinal lesions was found. Diagnodent tends to overscore discolored surfaces.