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Objective To investigate the therapeutic effects of penetrating resin and fluoride on early enamel caries. Methods Sixty intact bovine incisors were immersed in demineralized solution for 24 hours to make bovine incisor enamel caries.The specimens were divided into four groups(n=15 for each group)according to the treatment methods:control group (CON)-immersion in artificial saliva, DF group-immersion in 0.05% fluoride solution daily, WF group-2% fluoride gel weekly and IC group-resin infiltration.After processing for four and eighe weeks,the microhardness of the surface of each group was measured.After the treatment for four weeks,the depth of penetration and the microhardness of the samples were measured. After 8-week treatment, all samples were reintroduced into the demineralized solution for 24 hours and the microhardness of the samples was measured again.Results Results of microhardness assessment showed that there were no significant differences in baseline values(after white spots)between four groups(P>0.05).After treatment for four weeks the microhardness value reached the peak in IC group. After treatment for eight weeks the microhardness values reached the peak in DF group and WF group.The values of microhardness were significantly higher at different time points in IC group than those of other groups(P<0.05).After 4-week treatment,the percentages of penetration depth were significantly higher in DF,WF and IC groups than those of control group(P<0.01).The penetration depth was significantly higher in IC group than that of DF group and WF group (P<0.05). There was no significant difference in the penetration depth between DF group and WF group(P>0.05).Conclusion For the early enamel caries penetration resin,the penetration percentage is significantly higher than the fluoride treatment.
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Objective To compare the occluding effect of conventional penetrating resin,Single Bond desensitizer,and penetrating resin combined with ethanol wet-bonding on dentin tubules.Methods Sixty isolated premolar teeth were prepared to form dentin discs.The 60 teeth were divided into 3 groups based on a random number table:Group A,conventional penetrating resin;Group B,Single Bond desensitizer,and Group C,penetrating resin combined with ethanol wet-bonding.Each group comprised 20 teeth.Dentin discs were split in half along the longitudinal axis.Half of the disc served as the control;the other half was coated with desensitizer.Microscopic characteristics of the dentin surface and profile were determined by using a field emission scanning electron microscope.Results In group A,70.10％±2.13％ of the dentin tubule openings were covered by the resin.The penetration depth was 50±10.59 μm,and the resin was short and discontinuous.In group B,86.35％±1.73％ of the dentin tubules openings were covered.The penetration depth was 69± 11.98 μm,and the resin was sparse.In group C,95.65％± 1.46％ of dentin tubules openings were covered.The penetration depth was 177±9.17 μm,and the resin was compact and filled.Conclusion Penetrating resin combined with ethanol wet-bonding occludes dentin tubules better than conventional penetrating resin and Single Bond desensitizer.
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Objective:To study the sealing effect of penetrating resin and fluid resin on the exposed dentin with self-etching and to-tal-etching methods,respectively.Methods:60 fresh extracted teeth were randomly divided into 4 groups(n =15).The enamel layer at the tooth neck was cut off,the dentin layer was exposed and adhered with penetrating resin Icon-Infiltration following Icon-Etch etching(group A),Icon-Infiltration following SE-Bond etching(group B),FiltekTMZ350X following SE-Bond etching(group C)and Prime &Bond NT combined with FiltekTMZ350XT following Gluma acid etching(group D),respectively.The morphological change of the dentin-resin interface was examined by the scanning electron microscope.The thickness of adhensive layer hybrid layer and the length of resin tag were measured.Data were statistically analysed.Results:Tight adhesion layer was observe in all groups.The hy-brid layer of the adhesive interface of group D was thicker than that of other groups(P <0.05);the resin tags in the dentin tubules of group A were longer than those of other groups(P <0.05);the bonding agent layer of group C was the thickest(P <0.05).Conclu-sion:The penetrating resin can form more effective protection layer on the exposed dentin surface and longer resin tags pernertrating in-to the dentin tubules than self-etch/total-etch bond system with fluid resin.