Abstract
BACKGROUND: Hunter-Schreger bands (HSBs) are distinctive optical features observed in enamel and are characterized by alternating dark and light bands that reflect the orientation of the enamel prism. Despite their clinical relevance, variations in HSB patterns across different tooth surfaces remain poorly understood. The aim of this study wass to correlate the width and density of HSB with the surface (labial, lingual, mesial distal and occlusal) of the tooth and the type of tooth. MATERIALS AND METHODS: Eighty intact permanent human teeth (20 each: incisors, canines, premolars, molars) from the maxillary and mandibular arches were sectioned in mesiodistal or labiolingual planes. Reflected-light photomicrographs (4× objective; Olympus CX20i) were analysed with ImageJ. HSB density was defined as the number of HSB pairs per millimetre (one dark + one light = pair). Group differences were assessed via repeated-measures ANOVA and independent t tests; p< 0.05. STATISTICAL ANALYSES: Repeated-measures ANOVA and independent t tests were used to assess differences of HSB densities among surfaces and tooth types. A p value of of p<0.05 was considered . RESULTS: Significant variations in HSB density were observed across tooth surfaces within each tooth type and between the maxillary and mandibular arches. Compared with molars, mandibular buccal surfaces presented greater mean HSB densities in premolars ( p=0.001) ( p=0.201),whereas lingual surfaces presented consistent patterns across all tooth types ( p<0.05). Notably, incisal/occlusal surfaces demonstrated the greatest variability, with mandibular incisors exhibiting greater densities ( p<0.001) than maxillary incisors ( p<0.001). CONCLUSION: This micrometric analysis provides detailed insights into the microstructural variations in the HSB across tooth surfaces, highlighting functional and anatomical influences. These findings underscore the clinical importance of HSB in adhesive restorations and enamel-related conditions, suggesting tailored approaches on the basis of tooth type and surface location. Further research is needed to explore the biomechanical implications and refine the clinical applications in dental practice.