Experimental Study On Prevention And Treatment Of Dental Caries With Silver Diamine Fluoride And Glutathione

Objectives To observe the effect of silver diamine fluoride（SDF）added glutathione（GSH）on the acid resistance of isolated dentin,the remineralization of demineralized dentin,the shear bonding strength and microleakage after resin restoration,to provide experimental basis for clinical prevention and treatment of early dental caries.Methods 1 Acid resistance experiment:the isolated teeth were selected and enamal was removed to expose the dental surface.The teeth were polished and randomly divided into three groups（n=15）.The open window of the tooth surface was respectively coated with SDF,SDF added with GSH,and deionized water.The samples after drug application were immersed in 0.1M lactic acid,and 1m L lactic acid was taken at 1 day,1 week,2 weeks,3weeks and 4 weeks.The concentration of Ca²⁺in lactic acid was tested by ethylenediamine tetraacetic acid（EDTA）complex ometric titration.2 Remineralization experiment of demineralized dentin:the dentin simples were selected and immersed in the demineralized solution for 72 hours to form demineralized dentin.The demineralized areas were respectively coated with SDF,SDF added with GSH,and deionized water.The p H cycle was carried out in the buffer solution,and the following tests were performed:（1）The surface calcium-phosphorus ratio of each group of samples was tested by energy-dispersiver X-ray spectrometer（n=5）;（2）The surface microhardness of each group of samples was tested by microhardness tester（n=10）;（3）The surface micromorphology of each group of samples was tested by scanning electron microscopy（n=1）.3 Shear bonding strength experiment:dentin samples were demineralized for 72 hours to form demineralized dentin and were randomly divided into 6 groups（n=10）.The demineralized dentin was treated with different pretreatments and coated with Clearfil SE Bond adhesice（SE）and Single Bond Universal adhesive（SBU）:Group SSES（SDF pretreatment,SE bonding）,Group GSES（SDF added GSH pretreatment,SE bonding）,Group SES（SE bonding）,Group SSBUS（SDF pretreatment,SBU bonding）,Group GSBUS（SDF added GSH pretreatment,SBU bonding）,Group SBUS（SBU bonding）.After bonding,all specimens were filled with Tetric N-Ceram Bulk Fill resin in the mold with inner diameter and height of 3 mm.After 24 hours,the shear bonding strength of each group was tested by universal testing machine.4 Microleakage experiment:V-type cavities were prepared on the buccal and lingual sides of the isolated teeth and immersed in the demineralized solution for 72 hours.After removal,the demineralized dentin were randomly divided into6 groups（n=10）and coated with different pretreatment and SE and SBU adhesives:Group SSEM（SDF pretreatment SE bonding）,Group SSBUM（SDF pretreatment,SBU bonding）,Group GSEM（SDF added GSH pretreatment,SE bonding）,Group GSBUM（SDF added GSH pretreatment dentin,SBU bonding）,Group SEM（SE bonding）and Group SBUM（SBU bonding）.All specimens were filled with Tetric N-Ceram Bulk Fill resin after bonded.All specimens were immersed in cold and hot cycles after buffer solution for 24hours.The buccal and tongue slices of each simple were sliced,and the microleakage of each group was observed under a stereomicroscope.5 Statistical analysis.Results 1 Acid resistence experiment:There were significant differences in the concentration of calcium ions dissolved at different time and different groups（P<0.05）.At each time point,the concentrations of dissolved calcium ions in SDF and SDF added with GSH groups were significantly lower than the control group（P<0.05）.There was no significant difference in the concentrations of dissolved calcium ions between SDF and SDF added with GSH groups（P>0.05）.The concentration of dissolved calcium ions in each group increased with time,with significant difference（P<0.05）.2 Remineralization experiment of demineralized dentin:the surface calcium-phosphorus ratio of SDF and SDF added with GSH groups were significantly higher than the control group（P<0.05）,and there was no significant difference in the calcium-phosphorus ratio between the two groups（P>0.05）.The surface microhardness of SDF and SDF added GSH group were significantly higher than the control group（P<0.05）and there was no significant difference between the two groups（P>0.05）.After SDF and SDF added with GSH to deal with demineralized dentin surface,scanning electron microscopy observation showed that dental surface sediment,dental tubules were blocked by sediment.3 Shear bonding strength experiment:SSES,GSES,SES,SSBUS,GSBUS,SBUS six groups of shear bonding strength difference was not significant（P>0.05）.4 Microleakage experiment:SSEM,SSBUM,GSEM,GSBUM,SEM,SBUM six groups of edge closed well,but there are edge microleakage.There was no significant difference in the microleakage of each group and gingival margin（P>0.05）.There was no significant difference in the microleakage grade among the SSEM,GSEM and SEM groups（P>0.05）.There was no significant difference in the grade of microleakage among SSBUM,GSBUM and SBUM groups（P>0.05）.There was no significant difference in microleakage between SEM and SBUM groups（P>0.05）.Conclusions The addition of glutathione to silver fluoride can improve the acid resistence solubility of dentin and promote the remineralization of demineralized dentin.Pretreatment of demineralized dentin with silver fluoride and glutathione did not affect the bond strength and edge sealing of self-etching adhesive system after resin restoration.Added glutathione to silver fluoride has a good preventive effect on dentin caries.Figure 7;Table 15;Reference 230...