Study Of Mechanoluminescence Materials For Oral Occlusal Examination

Objectice:In order to improve the accuracy and sensitivity of traditional occlusal examination,a mechanoluminescent material SrAl₂O₄:Eu²⁺,Dy³⁺?SAOED?was compound with denture base resin?DBR?.To explore the feasibility of this composite for clinical use,its friction performance,mechanical properties and biocompatibility were tested.Materials and methods:High temperature solid state method was used to prepare the mechanoluminescence material SAOED with various doped proportion of Eu2+and Dy3+.XRD,UV-vis and SEM were used to test the crystal structure and absorption spectrum of SAOED.The luminescence property of SAOED was characterized with photoluminescence?PL?,afterglow spectra and mechanoluminescence?ML?.Prepared SAOED powder was mixed with DBR powder with various proportion to produce SAOED/DBR composite consist of different amount of mechanoluminescence material.Tribological properties and hardness of SAOED/DBR composite were tested by a CSM reciprocating tribometer and Shore durometer respectively.MTT assay was used to test biocompatibility of the composite.Results:1.XRD and UV-vis demonstrate that SAOED doped with Eu²⁺and Dy³⁺was successfully made without disturbing the crystal structure of SrAl₂O₄.The SEM of the morphological structure of SAOED material shows that the dispersibility of material is good and the size of SAOED is about10?m.2.The SAOED powder was composited with epoxy resin rigid carrier.By changing the doping concentration of Eu²⁺?1%,2%,3%,4%?and the doping concentration of Dy³⁺?1%,2%,3%?,the SAOED system was studied for its photoluminescence,afterglow decay,and mechanoluminescent properties.The results showed that when the doping concentrations of Eu²⁺and Dy³⁺were 2%and1%,respectively,the SAOED material had the strongest PL and short afterglow time.When the dynamic stress with a rate of 100N/s on the composites is higher than a certain value,the luminescence intensity increases with the increase of the stress,and there is a good positive correlation between the luminescence intensity and the stress.3.The SAOED/DBR composites with different weight ratios?1:8,1:7,1:6,1:5?were prepared by combining the optimized SAOED powders with dental base resin?DBR?.The results showed that SAOED can exhibit bright PL in DBR matrix.The tribological performance test results show that the friction coefficient of SAOED/DBR composite material has no obvious change compared with DBR control group.When the SAOED/DBR doping weight ratio is 1:7,the volume wear rate is the lowest,and the wear resistance performance is enhanced.Shore hardness test results show no difference in hardness between SAOED/DBR composites and DBR.MTT results showed that compared with the blank and control group DBR,SAOED/DBR composites had no effect on the growth and proliferation of L929 cells,and the composite material had no cytotoxicity.4.Use the optimized SAOED powder and DBR to make dental tooth model and oral standard model.By simulating the squeezing and rubbing behavior in oral environment,the bright light of the teeth model's stress area can be seen.Conclusions:1.When the doping concentrations of Eu²⁺and Dy³⁺in SrAl₂O₄:Eu²⁺,Dy³⁺mechanoluminescent materials are 2%and 1%,respectively,the photoluminescence and the mechanoluminescence properties are the strongest,and the afterglow time is short,showing the best optical performance.2.When the doping weight ratio of SAOED/DBR composite is 1:7,it has the best friction and wear performance and good biocompatibility.3.The mechanoluminescence of artificial tooth model prepared with SAOED/DBR composites by simulating the tooth's crushing friction behavior in oral environment showed that the composite of SAOED is a more accurate and more convenient method for artificial tooth occlusal examination.It can provide experimental basis for its application in oral occlusal examination.