SEM Morphology of Peritubular and Intertubular Root Dentin of Young, Adult and Senescent Teeth

Dentin is considered as a peculiar tissue regarding new insights about its composition. Dentine is composed of tubules surrounded by a hyper-mineralized layer called peritubular dentin, and a softer intertubular matrix. Its organic components concentrates in form of collagen fibrils and non-collagenous proteins and complex macro-molecules. The aim of this study is to analyze the morphology of peritubular and intertubular dentin of young, adult and senescent teeth in the coronal, middle and apical sections of the root. Permanent human third molars (n=30) were examined by SEM. Our study is in parallel to the recently proposed model of peritubular dentin that provides novel evidence about structure and chemistry of peritubular dentin. It lacks collagen fibrils, contains an organic scaffold embedded with mineral and the peritubular dentin organic matrix is manly composed of glycosaminoglycans, whereas the lamina limitans is primarily made of proteoglycans protein cores. Age-related characteristics of root dentin are evident in peritubular meshwork thickening, reduction of inter-fibrillar connections and mineral deposition within the tubules.