Objective: The guidelines of minimum intervention recommend the maintenance of the affected dentin; in the other hand, there are few methods able to analyze the presence of intratubular collagen. The objective of this study was to assess the collagen structure in carious dentin.
Study design: Ten collected samples of infected and affected dentin were stained with hematoxilin-eosin (HE) and Sirius Red (SR). The areas intensively stained with SR were delimited and the percentage of these areas was measured by double-blind calibrated examiners. The mean results were subjected to the t-student test. The amount of dentinal tubules and their area (pixels) were evaluated by HE, and subjected to the Mann Whitney test.
Results: The mean of dentinal tubules in the infected dentin was 213.22 and in the affected dentin it was 120.85 (p < 0.05). The mean area of dentinal tubules in the infected dentin was 1175.16 and in the affected dentin was 1420.70 (p > 0.05). The percentage of intratubular organized collagen in the infected dentin was 12.71% and in the affected dentin it was 32.37% (p < 0.05).
Conclusions: The histological evaluation of the collagen is a reproducible method to perform the morphometry in carious dentin and the affected dentin presents structured collagen areas where reorganization is possible.