Rare Earth Upconversion Luminescent Material Mixed Resin-modified Glass Ionomer Cement(RMGIC)

ObjectiveNaYF₄:Yb,Tm,a rare earth upconversion luminescent material with different mass ratio,was doped into resin-modified glass ionomer cement?RMGIC?to prepare the modified material.Then the near-infrared light with 980 nm wavelength was used to realize its deep curing.The mechanical properties and optical indicating properties of the modified material were studied,meanwhile,to explore the feasibility of the upconversion luminescent material modified dental filling material and the influence of doping ratio and light conditions on curing depth and mechanical properties.Materials and methods1.NaYF₄:Yb,Tm powders with the mass ratio of 0.5 wt%,1.0 wt%,3.0 wt%and5.0 wt%were mixed with resin-modified glass ionomer cement?RMGIC?by mechanical grinding to prepare the modified material,and the morphology of the modified material was analyzed by field emission scanning electron microscope?FESEM?.2.980 nm near-infrared light with power intensity of 0.1,0.3,0.5,0.7,0.9,1.0,2.0,3.0,4.0 and 5.0 W was used as the excitation light to irradiate samples with different doping concentrations,and the emission spectra were obtained and compared.3.Curing depth test,three points bending test and compressive strength test of 0.5wt%,1.0 wt%,3.0 wt%,5.0 wt%NaYF₄:Yb,Tm doped concentration modified material were conducted.4.Preparing the in vitro filling model with the optical indicative properties of the modified material.ResultsThe modified material could be cured in deep layer under 980 nm near-infrared light irradiation.When the doping ratio was 5.0 wt%,the curing depth could be more than 4 mm after 120 s of 2.0 W near-infrared light irradiation.Three point bending test and compressive strength test showed that the flexural strength and compressive strength of the modified RMGIC were not affected by the doping of 0.5 wt%,1.0 wt%,3.0 wt%,5.0 wt%NaYF₄:Yb,Tm.Under 980 nm infrared light irradiation,the filling material and healthy tooth tissue could be distinguished well,suggesting that it possessed optical indicating property.ConclusionThe resin-modified glass ionomer cement mixed with rare earth upconversion material NaYF₄:Yb,Tm could realize deep curing under 980 nm near-infrared light irradiation.The mechanical strength of the modified material would not be affected,and it exhibited good optical indicating performance,showing high potential clinical application value.