分光光度法与目测法测量义齿基托树脂色稳定性的比较研究

目的 探讨分光光度法与目测法测量义齿基托树脂色稳定性的相关性,以期确定分光光度法中的界值色差.方法 选取A、B两种红色义齿基托树脂(牙科丽义齿基托聚合物BQ-1,色号分别为2和3),各制作33个圆形试片,对试片一侧进行不同时间的光照处理,使其变色.30名色觉正常且具有1年以上口腔修复临床经验的口腔医学研究生分别对试片进行目测判定,结果计为"不变色"、"轻微变色"或"严重变色".用SP62分光光度仪测量试片两侧的色度值L*、a*、b*,计算色差△E.以色差△E为横坐标,以目测观察判定为"严重变色"的人数比例为纵坐标,绘制两种树脂的Logistic曲线.以50%观察者判定为"严重变色"时所对应的色差值,作为分光光度法的界值色差.结果 A、B树脂Logistic曲线的R2值分别为0.93和0.94;界值色差分别为2.87、2.82.结论 义齿基托树脂色稳定性评价中,分光光度仪数值测色方法与目测方法具有较好的相关性,不同色号的红色义齿基托树脂的界值色差相近.

Abstract：

Objective To explore the relationship between the spectrophotometric and visual methods in evaluating the color stability of denture base resin, and determine the threshold color difference of denture base resin in the spectrophotometric method. Methods Two kinds of denture base resin were respectively fabricated into 33 specimens whose color differences varied from indistinguishable to obvious.Each of the specimens was assessed respectively by 30 human observers and a SP62 spectrophotometer. The results of visual assement were recorded as "indistinguishable change", "light change" or "severe change",while the spectrophotometric color differences ( △ E) were calculated. In each group, a logistic curve was explored to determine the relationship between the color difference ( △ E) and the ratio of "severe change".Results The R squares of logistic curves were 0. 93 and 0. 94 respectively. The threshold color differences in the spectrophotometric method were 2. 87 and 2. 82 respectively. Conclusions A high relevance between the spectrophotometric and visual methods in evaluating the color stability of denture base resin was found.The threshold color differences for different color denture base resins were similar.

Comparative study on spectrophotometric and visual methods for color stability of denture base resin

Objective To explore the relationship between the spectrophotometric and visual methods in evaluating the color stability of denture base resin, and determine the threshold color difference of denture base resin in the spectrophotometric method. Methods Two kinds of denture base resin were respectively fabricated into 33 specimens whose color differences varied from indistinguishable to obvious.Each of the specimens was assessed respectively by 30 human observers and a SP62 spectrophotometer. The results of visual assement were recorded as "indistinguishable change", "light change" or "severe change",while the spectrophotometric color differences ( △ E) were calculated. In each group, a logistic curve was explored to determine the relationship between the color difference ( △ E) and the ratio of "severe change".Results The R squares of logistic curves were 0. 93 and 0. 94 respectively. The threshold color differences in the spectrophotometric method were 2. 87 and 2. 82 respectively. Conclusions A high relevance between the spectrophotometric and visual methods in evaluating the color stability of denture base resin was found.The threshold color differences for different color denture base resins were similar.