Effect Of Different Filling Methods On The Properties Of Acoustical Resin For Filling Class Ⅱ Cavity Of Posterior Teeth

Objective:To compare the marginal closure,tightness and mechanical properties of SonicFill bulk filling resin and conventional resin for delamination and holistic filling of dental cavity,so as to provide reference for its clinical application.Methods:40 molars in vitro were prepared into a class II cavity with buccolingual diameter of 4 mm,crown height of 4 mm and gingival wall width of 4 mm,washed,etched enamel for 30 seconds,coated with self-etching binder and illuminated for 10 seconds.The extracted teeth were randomly divided into two groups:AB group(n=20),A group with one side cavity(A1=20):SonicFill bulk filling resin with 2 mm in each layer;A group with the other side(A2=20)filled with Neofil conventional filling resin with 2 mm in each layer,B group with one side cavity(B1=20):Sonic Fill bulk filling resin with 4 mm in whole;B group with the other side(B2=20):Routine resin Neofil filling 4 mm.The teeth were stained with 2%methylene blue in 37 C water bath for 24 hours.The teeth were sliced along the distal and near directions by a low-speed microtome.The dye leakage of gingival wall was observed under a visual microscope.Scanning electron microscopy(SEM)was used to analyze the marginal cohesion between the bulk filling resin and conventional resin,and the degree of resin curing was analyzed by microhardness test.Results:The marginal microleakage of SonicFill slicing and bulk filling group was lower than that of Neofil group,and that of SonicFill bulk filling group was lower than that of slicing filling group(P<0.05).Scanning electron microscopy(SEM)results showed that the edge tightness of SonicFill bulk filling group was also better than that of other groups.Vickers hardness analysis results showed that the Vickers hardness of Sonic Fill stratified filling group was highest and the more complete.At the same time,SonicFill posterior teeth resin has good mechanical properties.Conclusions:SonicFill bulk flowable resin filling material has better edge sealing and tightness than conventional resin filling materials,regardless of the whole filling and layered filling.At the same time,SonicFill posterior teeth resin has good mechanical properties.