【作者】 李艳；

【导师】 冯云枝；

【作者基本信息】 中南大学 ， 口腔医学， 2012， 硕士

【摘要】 目的通过建立离体牙实验模型,并对其进行漂白处理,采用Olympus Crystaleye全牙分光光度牙齿比色仪测量其漂白前后的色度,分析比较不同类型的着色模型之间以及牙体颈、中、切三个区域之间的差异,为临床上设计治疗方案提供依据。材料与方法收集并选择因正畸需要拔除的前磨牙80颗,将其随机分为四组：内着色组、外着色组与联合着色组各20颗,对照组8颗,另选取12颗牙测量最佳着色茶浓度。将标本按各离体牙着色模型的制作方法制备,利用Beyond冷光美白技术对其漂白,利用全牙分光光度比色仪在漂白前以及漂白后第0、1、3、5、7、14天各时间点对各标本的颈、中、切三个区域进行比色,分别得到各组患牙漂白前后颜色差异的数据,包括⊿E、⊿L*、⊿a*及⊿b*。比较不同类型的着色模型之间以及牙体颈、中、切三个区域之间的差异。观察漂白后牙齿颜色回复随时间变化的趋势及程度,并比较三组间的差异。结果1.建立离体牙茶着色模型的最佳红茶浓度为4g/100ml；2.三组着色牙模型在漂白后即刻均获得较好的漂白效果,实验牙颈、中、切的L*值均增高,大部分实验牙的a*及b*值均降低；3.漂白后5天内,三组实验牙均出现了较快的颜色回复,其中内着色组颜色回复速度最快。内着色组、外着色组以及联合着色组三组之间颜色回复程度不同,差异有统计学意义(p<0.05),内着色组颜色回复变化值较外着色组大,差异有统计学意义(p<0.05)。4.内着色组实验牙漂白后切端的总色差⊿E以及⊿L*大于中部(p<0.05),中部又大于颈部(p<0.05)。联合着色组实验牙漂白后切端的总色差⊿E大于颈部(p<0.05)。但是在外着色组中,颈、中、切三个区域之间的差异不明显。5.内着色、外着色及联合着色三组间,牙颈部、中部及切端的⊿E均不一致,差异具有统计学意义(p<0.01)。外着色组颈部与中部的⊿E大于联合着色组,联合着色组又大于内着色组,差异均具有统计学意义(p<0.05)；外着色组切端的⊿E大于内着色组及联合着色组,差异具有统计学意义(p<0.05)。内着色、外着色及联合着色三组间,牙颈部、中部及切端的⊿L*均不一致,差异具有统计学意义(p<0.05)。外着色组的颈、中、切的⊿L*大于内着色组及联合着色组(p<0.05)。内着色、外着色及联合着色三组间,牙颈部、中部及切端的⊿a*均不一致,差异具有统计学意义(p<0.05)。外着色组的颈、中、切的⊿a*大于内着色组及联合着色组(p<0.05)。联合着色组颈部的⊿a*大于内着色组,差异具有统计学意义(p<0.05)。内着色、外着色及联合着色三组间,牙颈部、中部及切端的⊿b*均不一致,差异具有统计学意义(p<0.05)。外着色组的颈、中、切的⊿b*大于内着色组及联合着色组(p<0.05)。联合着色组颈部的⊿b*大于内着色组,差异具有统计学意义(p<0.05)。结论1.采用红茶溶液可制备出内着色、外着色及联合着色牙体外实验模型；2.对内着色、外着色及联合着色组实验牙进行Beyond冷光美白技术漂白,可获得较理想的漂白效果；3.三组实验牙漂白后颜色回复程度与速度均不同,内着色组回复程度与速度较大；外着色组漂白效果较其他组显著,且颈、中、切三个区域差异不明显；内着色及联合着色组漂白后,颈、中、切不同部位的效果不一致,切端的漂白变化最大,颈部最小；4.漂白前后不同类型着色牙及牙体不同区域颜色变化存在差异,提示临床上进行漂白治疗前应根据着色牙不同状况设计个体化治疗方案。更多还原

【Abstract】 Objective To establish the intrinsic, extrinsic or mixed discoloration models in vitro and to measure the chroma parameters of them before and after bleaching operations with the spectrophotometric tooth colorimeter (Olympus Crystaleye); To obtain the chroma alteration data after bleaching and to compare the data of the three models and three areas of teeth, neck, central, and incisal margin parts; To provide the evidence for making the individual bleaching plans.Materials and MethodsEighty premolar teeth extracted according to orthodontics needs were collected and randomly allocated into4groups, including intrinsic discoloration group (IDG), extrinsic discoloration group (EDG), mixed discoloration group (MDG) and control group. There were20teeth for each of the experimental groups and8teeth for the control group. Twelve teeth were used to measure the optimistic concentration of black tea for staining. After the samples of three models and control group were prepared, they were bleached with BEYOND whitening method. The spectrophotometric tooth colorimeter was used to measure the chroma parameters (⊿E,⊿L*,⊿a*,⊿b*) of the neck, central, and incisal margin areas of the samples before bleaching and different time points (0d,1d,3d,5d,7d,14d) after bleaching. The comparisons of the chroma alteration data among three different groups and three different areas of teeth were made. The extent and speed of color recurrence were observed and the comparisons among three groups were made.Results1. The optimistic concentration of black tea for staining the in vitro models were4g/100ml.2. The moment after bleaching, fantastic whitening effect was obtained in all the three in vitro models. The value of L*of all the samples became higher. However, the values of a*and b*of most of the samples became lower.3. During the first5days after bleaching, rapid color recurrence happened in all the three groups and most rapid speed was in IDG. The extent of color recurrence differed among three groups (p<0.05). The extent of that in IDG was much more than that in EDG (p<0.05).4. In IDG, the values of⊿E and⊿L*of the incisal margin area were more than that of the central area (p<0.05), which was more than that of neck area (p<0.05) after bleaching. In MDG, the values of⊿E of the incisal margin area were more than that of the neck area (p<0.05). However, in EDG, the differences among the three areas were not significant.5. The value of⊿E of the neck, central, and incisal margin areas differed significantly among IDG, EDG and MDG (p<0.01). The values of⊿E of the neck and central areas in EDG were more than those in MDG, which were more than those in IDG. The values of⊿E of the incisal margin area in EDG were more than those in MDG and IDG.The value of⊿L*of the neck, central, and incisal margin areas differed significantly among IDG, EDG and MDG (p<0.05). The values of⊿L*of the neck, central and incisal margin areas in EDG were more than those in MDG and IDG.The value of⊿a*of the neck, central, and incisal margin areas differed significantly among IDG, EDG and MDG (p<0.05). The values of⊿a*of the neck, central and incisal margin areas in EDG were more than those in MDG and IDG. The value of⊿a*of the neck area in MDG were more than that in IDG (p<0.05).The value of⊿b*of the neck, central, and incisal margin areas differed significantly among IDG, EDG and MDG (p<0.05). The values of⊿a*of the neck, central and incisal margin areas in EDG were more than those in MDG and IDG. The value of⊿b*of the neck area in MDG were more than that in IDG (p<0.05).Conclusion1. Black tea could be used to establish the intrinsic, extrinsic or mixed discoloration models in vitro;2. Beyond Whitening Technique could be used to bleach all the three modles and fantastic whitening effect was obtained; 3. The speed and degree of color recurrence differed in three models. The values of them in intrinsic model were higher than those in other two models. The bleaching effect of EDG was more significant than the other two. The regional differences among incisal, central and neck areas were not significant in EDG, but were significant in IDG and MDG. The chroma alteration was most significant in incisal region and least significant in neck region in these two models;4. The values of chroma alteration differed among three models in vitro and three regions of one teeth. It suggested that individual bleaching plan should be made according to the different situation of individual teeth before the treating.更多还原