Preparation And Properties Of Living Pulp Preservation Materials Based On Bioactive Glass

Pulp is a kind of honeycomb soft tissue distributed in the pulp cavity and root canal.It is mainly connected to the outside through the apical foramen to provide nutrients to maintain the normal physiological activities of the teeth.Due to its non-renewable characteristics,the living pulp preservation is crucial.In recent years,there are many deficiencies in clinically used living pulp preservation materials such as calcium hydroxide,calcium phosphorus biomaterials,and mineral trioxide aggregates.Therefore,it is of great significance and clinical value to develop a pulp preservation material for dental pulp repair with suitable cost,good physical and chemical properties,biological activity,degradability,and promotion of dentin repair characteristics.This article first combined the sol-gel method and the organic template method to prepare a spherical micro-nano bioactive glass(MNBG)with consistent morphology and good dispersion.Using MNBG as the solid phase and chitosan phosphate buffer as the liquid phase,a composite living pulp preservation material that can self-solidify quickly and has good biological activity is prepared.On this basis,by adding tricalcium phosphate(TCP)to the solid phase,the performance is further improved,and a new composite living pulp preservation material based on bioactive glass is finally obtained,and its physical?chemical and biological properties are further improved,the main research content is as follows:(1)Based on the sol-gel method,dodecylamine is added as a template to obtain micro-nano spherical bioactive glass with good bioactivity and dispersibility.It was found that it had a uniform particle size distribution,a large specific surface area,good monodispersity and in vitro mineralization activity,and provided a theoretical basis for the subsequent preparation of living pulp preservation materials.(2)Use prepared MNBG as solid phase and chitosan phosphate buffer as liquid phase to obtain MNBG/CS living pulp preservation material.By adjusting the concentration of chitosan(CS)solution in phosphate buffer,the material has self-curing properties.Further research on the properties of the paste found that a large amount of hydroxyapatite will be generated during the curing process,which has good in vitro mineralization activity;different concentrations of c chitosan phosphate buffer will affect the curing time of the material,but its compressive strength has little effect;the repeatability of the experiment is good,the performance of the obtained material is stable,and the operation is simple.At the same time,the MNBG/CS living pulp preservation material also has good biocompatibility,and has a good effect of promoting bone differentiation when cultured with human dental pulp stem cells at an appropriate concentration.(3)On the basis of the previous research,MNBG/CS/TCP living pulp preservation materials were prepared.The physical and chemical properties of the material were improved by adding TCP to the solid phase,and the effects of different amounts of TCP on the setting time,compressive strength,in vitro mineralization activity,in vitro degradation,biocompatibility and other properties were discussed.The study found that the compressive strength and setting time of materials made with different amounts of TCP are different,and the morphology of the hydroxyapatite crystals formed on the surface is also different.As the TCP content increases,the compressive strength of the material increases significantly,and all have good biocompatibility,and have no inhibitory effect on the growth of dental pulp cells.In this paper,we successfully prepared a new type of living pulp preservation material based on bioactive glass.A large number of tests have proved that the MNBG/CS/TCP living pulp preservation material can be quickly self-cured,with high strength and good in vitro mineralization activity and biocompatibility.The experiment has good repeatability,the obtained material has stable performance,simple operation and suitable cost,and is expected to be further used in clinical research.