The Effect Of Sealing Dentinal Tubule For Three Kinds Of Desensitizers:A Vitro Study

Objectives To compare the dentinal tubule occlusion ability of Gluma desensitizer,Green? Or desensitizer and a two-step adhesive Clearfil Se Bond,to evaluate the Dentin blockage and abrasion resistance of Clearfil Se Bond used to treat dentin hypersensitivity,provide a theoretical basis for clinical treatment of DH.Contents In this experiment,dentin sensitive models(dentin disc)were prepared from isolated teeth and the dentin discs were treated with three kinds of desensitizers.The brushing experiment was also performed on the treated dentin discs,then the samples were evaluated by scanning electron microscope and image analysis software.Dentinal tubule occlusion and anti-abrasion capabilities of the three desensitizers were assessed,including qualitative and quantitative analysis.Methods 1.Collecting the isolated tooth: The collected isolated teeth were the third molars extracted in the clinic for impaction,without periodontal disease,tooth defect and cracked.The soft tissue and calculus around the tooth were removed.After ultrasonic washed in saline the teeth were stored in 4 ° C saline for use.2.Preparation of dentin sensitive models: Refer to the method of dentine disc in the previous literature,Thirty-two dentine discs were prepared and ultrasonic washed under physiological saline then stored them in saline at 4 °C.3.Grouping and processing: Thirty-two DH models were randomly divided into control group(Co,n=8),Gluma desensitizer group(GD,n=8),Green? Or desensitizer group(GOD,n=8)and Clearfil Se Bond group(CSEB,n=8).In the latter three groups,the dentin discs were symmetrically divided from the middle into two half-round specimens and one half was selected to as the subgroups(brushing experiment groups).Distilled water was used as a control in the Co group,while GD group,GOD group,and CSEB group specimens were respectively treated with Gluma desensitizer,Green? Or desensitizer and Clearfil Se Bond.The same treatment was carried in the subgroups and following that brushing experiment was accomplished.4.Electron microscopy scanning: After all the samples were fully dried naturally,the treated surface was scanned with a scanning electron microscope.Each specimen was scanned in the dentin surface of the central area and randomly photographed to obtain a 2000 x scanning electron microscopy image.Observe the effect of dentinal tubules occlusion and blockage by qualitative analysis.5.IPP Quantitative Analysis: All the images were analyzed with Image-Pro Plus6 image analysis software.The unit of pixels in the figure can be converted to actual units by the ruler tool.The average diameter and total areas of open dentine tubules can be accurately measured.The data of all groups were analysed with SPSS 16.0 and the statistical analysis and differences between groups were performed.Results 1.The total area of dentinal tubules in the GD group,GOD group,and CESB group was smaller than that in the CO group(P=0.000);there was no significant difference in the total dentinal tubule area between the GD group,the GOD group,and the CESB group(P>0.05).The total area of dentinal tubules in the GD group,GOD group,and CESB group was smaller than the total dentinal tubule area of the corresponding brushing group(P≤0.001);the total area of the GOD brushing group was significantly larger than that of the GD brushing group and the CESB brushing group(P=0.000),there was no significant difference between the latter two groups(P=0.688).2.There was no significant difference in average diameter between CO group and GOD brushing group(P=0.090).There was no significant difference in mean diameter between GD group and GD brushing group(P=0.160).The average diameters btween other groups were significantly different,the size sorting: CO group=GOD brushing group>GD brushing group=GD group>CESB brushing group>GOD group>CESB group(P=0.000).Conclusion 1.All the three kinds of desensitizers have excellent dentinal tubule sealing effect.The closed layer formed by Clearfil Se Bond is the most dense and uniform,followed by Gluma desensitizer,while the Green? Or desensitizer is the most loose.2.The Green? Or desensitizer’s sealing layer has the worst wear resistance and is easily detached after being worn.Both the sealing layers formed by Clearfil Se Bond and Gluma desensitizer have excellet wear resistance.