Enamel Surface Morphology: An Ultrastructural Comparative Study of Anterior and Posterior Permanent Teeth

INTRODUCTION: Enamel is one of the most important structures of the tooth, both functionally and aesthetically. Because of the highly mineralized nature of enamel, its structure is difficult to study under routine light microscopy. Since scanning electron microscopy (SEM) offers the possibility of studying structures under very high magnification without altering the gross specimen, it is one of the best methods to study the enamel surface. AIMS AND OBJECTIVES: To study and compare the surface morphology and morphometry of enamel on various surfaces of permanent dentition. MATERIALS AND METHODS: A total of 20 permanent teeth were analyzed under the SEM. In both anterior and posterior teeth, four surfaces – mesial, distal, labial, and lingual – in three thirds – cervical, middle, and incisal – were studied. In addition, the occlusal surface was also studied for the posterior teeth. The different prism morphology and prism dimensions were recorded. RESULTS: Based on our observations, we could definitely identify striae of retzius, debris, and cracks under ×50 magnification. Three morphological patterns of prism arrangement were identified: Type 1 - shallow prisms, Type 2 - well-defined prisms, Type 3 - microporosities, on analyzing the mesial, distal, labial, lingual, and occlusal surfaces of the permanent teeth, at ×3000 magnification. The prisms were measured under ×6000 magnification and the results showed larger prisms in posterior than in anterior teeth. CONCLUSION: The study aided us in categorizing the enamel prism structure based on morphology and morphometry in anterior and posterior teeth of the permanent dentition.