Histopathology of Caries in Dentin Under Various Microscopy Techniques: A Comprehensive Review

Caries in dentin represents a complex pathological process characterized by progressive demineralization, bacterial invasion, and organic matrix degradation of dentin tissue. Understanding the histopathological progression through advanced microscopy techniques remains essential for accurate diagnosis and optimal treatment planning. This review examines the five classical zones of dentinal caries and evaluates the efficacy of various microscopy modalities in their visualization and characterization. Multiple microscopy techniques contribute unique perspectives on carious lesion characterization. Conventional light microscopy and polarized light microscopy effectively demonstrate zone differentiation through birefringence patterns and optical properties. Stereomicroscopy enables gross morphological assessment of surface characteristics and lesion extent. Electron microscopy, including scanning and transmission variants, provides ultrastructural details of tubular architecture, bacterial morphology, and mineral-organic interactions at nanometer resolution. Confocal laser scanning microscopy offers three-dimensional optical sectioning with quantitative depth measurement capabilities. Advanced imaging modalities such as micro-computed tomography and optical coherence tomography enable non-invasive volumetric assessment and real-time lesion monitoring. Additionally, a few digital schematic images have been designed by authors for better understanding of caries in dentin. This attempt might provide a better understanding for students and enhance diagnostic accuracy for improved clinical outcomes.