Comparative Evaluation of Deciduous and Permanent Coronal Caries Using Polarizing Light Microscopy and Scanning Electron Microscopy

<b>Background:</b> Dental caries causes mineral loss and organic damage to teeth. Understanding caries and dentin pulp reactions is crucial for effective caries management strategies. There is a lack of knowledge regarding the microscopic and ultramicroscopic changes that occur during caries destruction and reactive changes. This study used polarizing and scanning electron microscopy to compare deciduous and permanent coronal caries. <b>Materials and Methods:</b> The study included 30 teeth, comprising 15 primary and permanent teeth, all with coronal caries. They were also compared with 10 (5 each) noncarious primary and permanent teeth. The teeth were examined using polarizing and scanning electron microscopy to study enamel and dentin destruction, reactive dentin formation, peritubular dentin destruction, and bacterial colonization. <b>Results:</b> Deciduous teeth had more enamel and dentin destruction for coronal caries than permanent teeth in our study. The permanent teeth had more reactive dentin formation than primary teeth. Peritubular dentine alteration was increased in deciduous teeth, and bacterial presence on dentin was higher in permanent teeth under scanning electron microscope. <b>Conclusion:</b> Our findings suggest that caries destruction is more prevalent in deciduous teeth, and reactive response is more effective in permanent teeth affected by caries. These findings reflect the structural durability of the mineralized tissues and prompt reactive response of the dentin pulp complex of permanent teeth compared to deciduous teeth. Our research highlights the importance of identifying and treating decay in primary teeth at an early stage.