Effects Of Opalescence Whitening System On Teeth Whitening And Remineralization For Demineralization And Colored Teeth After Orthodontic Treatment

Objective: The models of incipient demineralization and shading were established in an artificial method.Through observing the enamel color and surface micro hardness,the effects of opalescence boost whitening system on teeth demineralization and coloring after orthodontic treatment were evaluated,which would provide reference for the clinical applications.Methods:1 Tooth preparation : 112 freshly extracted adolescent premolars of patients for orthodontic reasons from the NO.2 Hospital,Hebei Medical University,were collected for the.The enamel and root were covered with two layers anti-acid nail oil except the labial surface after cleaned and disinfected.2 Preparation of enamel demineralization shading models: To establish incipient enamel demineralization and coloring models,the teeth will be soaked into the partial saturated acid buffer with 37?constant water bath for one week,and then soaked into the tea in the same conditions for three days.3 Different treatment methods:112 teeth were then randomly divided into four group(Group A?B?C?D n=28):Group A(Opalescence):Opalescence whitening agent.Group B(Beyond): Beyond whitening agent.Group C(Fluoride foam): Fluoride foam.Group D(contral)deionized water.4 To measure the brightness levels,micro-hardness and microscopic shading depth:The brightness levels(M)of samples in A?B?C?D groups were compared with Ultradent shade guide in four distinct stages:pre-treatment?immediately after treatment(t0)?two weeks after treatment(t2)?four weeks after treatment(t4).The depth of enamel coloration(L)of samples in four groups were observed with the Leica microscope at the time of pre-treatment?t0?t2?t4.The surface micro-hardness values(SMV)of samples in four groups were measured with Vickers hardness tester in the same four distinct stages.All data was analysed by the statistical software SPSS 17.0.X±S was used for descriptive statistics.ANOVA was used for between-group and within-group comparison.The S-N-K test or Dunnett's T3 test was carried out for further pairwise comparison.Result:1 Colorimetric with Ultradent shade guideThe comparison of values of M before treatment among group A?B?C?D show that the data satisfied normal distribution and homogeneity of variance,One-Way ANOVA P>0.05.there were no significant statistical difference among the three groups,indicating that the shading level of the four groups before treatment were consensus.To analyze the bleaching effect of differerent treatments in different stages,One-Way ANOVA displayed that any other two groups were significantly different(P<0.05)in t2 and t4 stage except group C and group D.The values of M in group A was the lowest revealing that it is the most effective group;The whole groups were not significantly different(P>0.05)in stage t2 apart from group A,and the group A is the most effective.To analyze the values of M in different time in each group,One-Way ANOVA showed that there were statistical differences(P<0.05)in group A and group B at different time.The lowest levels of group A and B were in stage t2,and the bleaching effect reached the best,and there were no significantly difference when compared with stage t4.2 Depth of shading on enamel under the microscopeThe values of L before treatment satisfied normal distribution and homogeneity of variance and there were no significant statistical difference(P>0.05)among three groups,indicating that the depth of shading on enamel of the A?B?C?D groups before treatments were consensus.To analyze the values of L in distinct stages of each group,the One-Way ANOVA showed there were no significant differences among B?C?D groups in stage t0 and t2(P>0.05),while there were significantly difference when compared with group A(P<0.05).The depth of shading in group A was the lowest among the three groups above,revealing the most effective bleaching in group A;There were no significantly differences(P>0.05)between group A and group B,group C and D.The shading depth in group A?B were significantly different when compared with group C?D(P<0.05).To analyze the values of L in each group at different time,the ANOVA revealed that there were no statistical differences(P>0.05)in each group except group B.It means that the best bleaching effect of group A was in stage t0,and group B was in stage t4.3 The surface micro-hardness values measured by micro-hardness testerThe SMV before treatment satisfied normal distribution and homogeneity of variance and there were no significant statistical difference(P>0.05)among A?B?C?D groups,revealing that the SMV on enamel of the four groups before treatments were consensus.The One-Way ANOVA of different groups in corresponding stages displayed that the SMV of four groups were not significantly statistical different(P>0.05)in t0 stage;There were significant statistical difference(P<0.05)between every two groups in t2 and t4 stages apart from group A and group C.The SMV of group A and C were almost the same and significantly higher than other groups,meaning that they had a higher degree of remineralization.The One-Way ANOVA of SMV in each group at different time showed that there were significant statistical difference(P<0.05)in A?B?C groups except group D,and the SMV reached the top in three groups above in stage t2,and the optimal degree of enamel remineralization at the same time,while not significantly different in stage t4.Conclusion:1 Bleaching effect of Opalescence Boost office whitening system is remarkable,which could meet the requirements of orthodontic patients.2 The demineralization enamel can be remineralized because of the fluoride contained in the Opalescence Boost office whitening system,but the short-term effect was not obvious.