Formation of Mineral Layer on Dentin Induced by Bioactive Glass

Objectives: To determine the effect of different size bioactive glass on the formation of mineral layer on dentin surface.
Methods: Totally demineralized dentin disks processed by EDTA were treated by three different size bioactive glass(BG), including nano-BG, submicro-BG, micro-BG and subsequently immersed in artificial saliva (AS). 1) Disks were examined by field emission scanning electron microscopy (FE-SEM) for the morphology of the deposition on the dentin surface and between the collagen after one and two weeks separately, the elemental compositions of these deposition were tested by Energy Dispersive X-ray Spectrometric Microanalysis (EDX). Image J-software was used on the FE-SEM images to evaluate the area of the sealing dentin tubules. 2) Disks treated by BG for two weeks were put into cola for 2min, the morphology was examined by FE-SEM, laser scanning electron microscopy (LSM) was used to quantitatively analyse the roughness variation of the dentin surface.
Results: 1) After one week, the area of sealing dentin tubules treated by nano-BG was larger than the other two groups, the contents of calcium and phosphate were higher too. Two weeks later , plug-like depositions were observed in the dentin tubules for the nano-BG treated dentin disks, also there was amount of deposition between the collagen and the peritubular dentin widen, while only plate-like deposition could be observed on the micro-BG and submicro-BG treated dentin disks . 2) After soaking in cola , most of the dentin tubules were still sealed for the nano-BG treated group , the roughness was also lower than the other two groups , the variation of the roughness was minimum for the nano-BG treated group.
Conclusions: The nano-BG can better induce formation of mineral to resist acid erosion , which could be a potential material for dentin remineralize.