The Efficacy Of ICOM Resin Infiltration To The Demineralization And Coloring Of The Enamel Surface After Orthodontic Treatment

Objective: After the treatment of clinical orthodontics, the teeth which were bonded brackets became demineralization and dyed. That is usually the critical factor that affecting the satisfaction of patients and doctor. Traditional operation therapy now can not meet the clinical needs. In recent years, resin infiltration technology came into being. It was infiltrated and filled into the de-mineralized enamel structure by capillary filling, clinically used for the treatment of early enamel caries and dental fluorosis. But there have not been reported in the literature for the effect of enamel de-mineralization and dyeing after orthodontic treatment.This experiment adopted the artificial method to establish the demineralization and dyeing model of enamel which was after the treatment of orthodontic. Through the comparison of changes in color, hardness and the depth of demineralization of the enamel surface before and after the use of ICON resin infiltration, OP whitening system and Fluoride Foam. We study the effect of ICON resin infiltration on the de-mineralization and dyeing enamel surface that were after the treatment of orthodontic and to provide theoretical support for clinical application.Methods:1 Tooth preparation: a sample of 112 sound premolars, indicated for orthodontic extraction from the second Hospital of He-bei Medical University, formed the study group. The teeth were covered with a nail polish, leaving the buccal surfaces of sound, intact enamel.2 Preparation of de-mineralized and dyed teeth model: Each tooth was subsequently immersed in de-mineralizing solution and then dying water with 37℃constant water bath to produce artificial demineralization and color samples.3 packet processing: The specimens were then randonmly divided into four groups（A, B, C, D, n=28）.The de-mineralized area was then infiltrated with Group A control deionized water, Group B Icon resin infiltrant, Group C Opalecence whitening system, Group D Fluoride Foam respectively according to the instructions of each manufacturer.4 Data measurement: the assessment of color was performed by the Ultradent shade guide in four distinct stages: before the treatment, after the different treatment immediately（T₀）, after two weeks（T₂）, after four weeks（T₄）, read the value of W. Every time after that tooth were then sectioned longitudinally through the lesion into two halves. One half of each sample was embedding with dental self-curing resin in order to measure the surface micro-hardness value（SMV）. The other half was made of tooth grinding to put in Optical Microscopy to observe the depth of de-mineralization.5 Statistical analysis: All data were analyzed statically with the software SPSS 17.0, the normal Distribution of the data was tested. So statistical description used ±s. Comparison between groups used Analysis of variance, further pair-wise comparison used SNK（Student-Newman-Keuls） test, according to the inspection standard α=0.05.Results: 1 The naked eye viewThe sample teeth enamel surfaces of Group A, B, C and D turned into dark red and became rough after demineralization and dyed. The enamel surfaces’ color of Group A had no effect after treated by de-ionized water immediately,with time going on, the changes were not obviously. The color of enamel surfaces of Group B had also no obvious changes immediately, but the roughness of enamel surfaces were reduced obviously and the lustrousness of surfaces were looked like the normal enamel surface. With time going on, the changes were not obviously, too. The color of enamel surfaces of Group C disappeared immediately after the treatment, but the roughness and lustrousness of the enamel surfaces were changed not obviously. The color of enamel surfaces of Group D had no obvious change immediately. As time goes on, the roughness of enamel surfaces reduced and the lustrousness were gained.2 The changes of the value of W2.1 The analysis of the value of W before the different treatment: the values of W of four groups satisfied normal distribution and equal variance, the single factor analysis of variance（ANOVA） P = 0.73 > 0.05, indicating the four groups were no significantly statistical differences, the W level of the four groups before treatments were consensus.2.2 The value of W of four groups after the treatment immediately were:18.00±0.82, 13.57±2.23, 2.86±2.04,17.43±0.98. after two weeks the values of W were: 17.71±1.25, 13.14±2.48, 6.71±3.55, 13.43±4.35. after four weeks the value of W were: 15.86±2.79, 15.86±1.07, 6.71±3.50, 15.86±2.12. The W values were compared respectively in groups, Single factor analysis indicating that there were statistical differences in groups（P<0.05）. SNK indicating that the W values of group C was the minimum in T₀、T₂、T₄. The values of W were compared respectively in times, Single factor analysis indicating that there were statistical differences in time of group C（P<0.05）, SNK indicating that the W values of T₂ was the minimum in group C.3 The changes of SMV3.1 The analysis of the SMV before the different treatment: the SMV of four groups satisfied normal distribution and equal variance, the single factor analysis of variance（ANOVA） P = 0.42> 0.05, indicating the four groups were no significantly statistical differences, the SMV level of the four groups before treatments were consensus.3.2 The SMV of four groups after the treatment immediately were: 209.58±34.92, 236.68±21.74, 213.06±37.95, 210.78±37.66. after two weeks the SMV were: 229.01±31.81, 424.48±56.38, 379.02±69.13, 355.93±28.98. after four weeks the SMV were: 251.62±29.63, 365.47±46.11, 352.03±36.85, 344.94±54.47. The SMV were compared respectively in groups, Single factor analysis indicating that there were statistical differences in groups of T₂、T₄（P<0.05）. SNK indicating that the SMV of group B was the maximum in T₂、T₄. The SMV were compared respectively in times, Single factor analysis indicating that there were statistical differences in time of group B, C, D（P<0.05）, SNK indicating that the SMV of T₂ was the maximum in group B.4 The changes of depth of demineralization4.1 The analysis of the depth of demineralization before the different treatment: the depth of demineralization of four groups satisfied normal distribution and equal variance, the single factor analysis of variance（ANOVA）P = 0.96> 0.05, indicating the four groups were no significantly statistical differences, the depth of demineralization level of the four groups before treatments were consensus.4.2 The depth of demineralization of four groups after the treatment immediately were: 0.145±0.020, 0.077±0.032, 0.096±0.020, 0.130±0.035. after two weeks the depth of demineralization were: 0.121±0.028, 0.025±0.022, 0.080±0.030, 0.116±0.048. after four weeks the depth of demineralization were: 0.114±0.021, 0.058±0.025, 0.121±0.054, 0.127±0.02. The depth of demineralization were compared respectively in groups, Single factor analysis indicating that there were statistical differences in groups of T₀, T₂, T₄（P<0.05）. SNK indicating that the depth of demineralization was the maximum in group B of T₀, T₂, T₄. The depth of demineralization were compared respectively in times, Single factor analysis indicating that there were statistical differences in time of group B（P<0.05）, SNK indicating that the depth of demineralization of T₂ was the minimum in group B.Conclusion:1 ICON resin infiltration penetrates into the enamel structure inside, filling and blocked the pores caused by demineralization. Reinforce and stabilize the de-mineralized enamel, improve the micro-hardness of enamel surface, decrease the depth of demineralization. The effect is better than OP whitening system and fluorinated foam.2 ICON can improve the glossiness of teeth which is better than OP whitening system, but to extrinsic staining, its effect is less than OP whitening system.