Preparation And Application Of Bioactive Glass Desensitizing Materials For Dentin Hypersensitivity

Some clinical situations,such as caries,abrasion and gingival recession,probably make the dentin be exposed to the oral environment,leading to dentin hypersensitivity,thus destroying the health and function of teeth.According to the hydrodynamic hypothesis,the effective strategy for treating dentin hypersensitivity is occluding dentinal tubules,inducing dentin regeneration.Fluoride,strontium chloride,calcium-phosphorus based materials and bioactive composites are widely used as dentin desensitizers.However,there are some drawbacks in these desensitizers.Therefore,it is significant to develop a new desensitizing material,with the ability to induce in situ remineralization of dentin and block off dentinal tubules effectively,which is also sample to operate,acceptable in terms of aesthetics and has a rapid and lasting effect.Bioactive glass(BG)is known for its higher biocompatibility and bioactivity that is able to bond to bone via the formation of a hydroxyapatite layer in biological environment,as well as anti-bacteria effect,resulting in playing an interesting candidate for dental restoration.This study focuses on the application of bioactive glass spheres for treating dentin hypersensitivity.There are two sections in the project: one is the preparation and characterization of bioactive glass spheres which are uniform in component,well-dispersed and controllable in particle morphology and size,the other is to study the effect of the particle size and morphology of BGs on the ability of facilitating dentin remineralization.Micro/nano bioactive glass spheres(MNBGs)with different particle size were synthesized by sol-gel method combining template self-assembly technology using dodecylamine(DDA)as template and catalyst.The particle size of MNBGs could be tailored through adjusting the concentration of DDA and the quantity of precursors.The apatite-forming ability of MNBGs with larger size behaved better.The ability of occluding dentinal tubules,inducing dentin remineralization and accelerating reparative dentin formation in artificial saliva for MNBGs with different particle size was investigated.The result showed that MNBGs could fill and seal the dentinal tubules better when their particle size matched the diameter of dentinal tubules.Dendritic mesoporous bioactive glass spheres(DMBGs)were fabricated in an oil-water biphase delamination reaction system,in which the surfactants assembled with the organic solvents at the interface to form O/W hemiemulsion micelles,which served as templates for the formation of the dendritic mesoporous channel.The material exhibited good dispersity,large mesochannel,high specific surface area and excellent ability of protein loading and sustained release.The capacity of occluding dentinal tubules and inducing dentin remineralization in artificial saliva for bioactive glass spheres with different mesostructure(MNBGs & DMBGs)was tested.The result indicated that there was no significant difference between DMBGs with mesoporous tructure and MNBGs with smooth surface in forming apatite and inducing the regeneration of reparative dentin.