上颌中切牙冠修复体的口腔色差容忍度研究

目的：研究上中切牙冠修复体在口内环境下的色差容忍度（包括察觉度和接受度），为提高配色技术成功率提供数据依据。方法：使用专业牙科比色仪器ShadepilotTM，测定66例单侧上颌中切牙冠修复体与对应天然牙的色差数据△E，以及各色度参数差△L＊、△C＊、△a＊、△b＊，根据每个患者在修复体戴入口腔后对其色差的主观感受，将病例分成三组：A组：不存在色差，效果满意；B组：存在色差，但效果满意；C组：存在色差，效果不满意。C组修复体在进行外部染色后再次进行色差测定，数据归入A组或B组，总色差与各参数色差分别进行统计分析，研究色差察觉度和接受度。结果：口腔环境中，上中切牙冠修复体色差察觉度约为1．6（△E单位），色差接受度平均为4．06（△E单位）；当修复体的明度L＊及饱和度C＊高于天然牙时，其色差容忍度相对较高，而修复体明度L＊及饱和度低于天然牙时，色差容忍度较低；色调差异△a＊的存在对色差容忍度的影响均比较显著。结论：口腔修复体的色差容忍度，不仅与肉眼观察生理特征相关，与心理因素也有着一定的关系，若能充分了解人们对修复体色彩的审美倾向，将色差容忍度定量运用于比色技术中，将对提高修复体配色成功率十分有利。

Study of the tolerance of color difference between upper-incisor-crown prosthesis and natural tooth.

Objective： To improve the color-matching technique, our study is aimed to provide the data basis of the tolerance for color difference （including perceptibility and acceptability） of upper incisor crown in oral cavity. Method： 66 single maxillary incisor crown prostheses and the corresponding nature teeth were measured by ShadepilotTM, a professional tooth-color-measuring instrument. The color differences △E, △L＊, △C＊, △a＊ and △b＊ were calculated for each case. The cases were divided into three groups after crowns had been tried in：A no color difference was perceived between prosthesis and natural tooth; B color difference could be perceived but acceptable; C color difference could be perceived and unacceptable. Prostheses in group C should be dyed and measured again,data would be classified into group A and B, and all the color difference data would be analyzed. Result： The tolerance for perceptibility of color difference between upper incisor prostheses and natural teeth is 1.6 △E unit, and the tolerance for acceptability is 4.06 △E unit. The tolerance of △L＊ and A C＊ for cases, that the crowns＇ value and saturation were higher than the natural teeth, were significantly higher than cases that on the contrary. The tolerance was significantly affected when hue △a＊ exist. Conclusion：The tolerance of color difference is related to the psychological factors closely, besides physiological factors. It will be beneficial to improving the color-matching technique if the tolerance data of color difference could be applied as a rule.