紫外线照射老化树脂黏固剂对色度值及相对透明率的影响

目的探讨紫外线照射老化对4种树脂黏固剂颜色及相对透明率参数的影响。方法分别采用Biscem（双固化型）、Choice（光固化型）、PermaCem（化学固化型）和RelyX Aplicap（化学固化型）树脂黏固剂制取树脂试件，每种黏固剂制取5个试件，分别设为A、B、C、D组，按厂家推荐的方法光照或自然固化。在黑暗环境保持24 h后用色度计测量色度值CIE L*、a*、b*，并计算其相对透明率。然后将各组试件分别经紫外线照射老化8、16、24 h后再次测量，分析色度值和相对透明率的变化。结果4组树脂黏固剂试件在紫外线照射后均发生了颜色变化，照射时间越长色差值越大。照射时间相同时，4组试件的色差值不同，B组与D组的色差值较小，C组最大。A、B与D组的相对透明率受紫外线老化的影响较小，C组在紫外线照射后相对透明率发生改变。结论紫外线照射老化能够引起树脂黏固剂发生颜色改变，但是多数产品的相对透明率能够保持相对稳定。

Effects of ultraviolet aging on color and translucency of composite resin cements

Objective To investigate the color stability and translucency of four composite resin cements after ultraviolet（UV） aging. Methods 20 composite resin cement disks for four groups（Group A, dual cured, Biscem; Group B, light cured, Choice; Group C, self cured, PermaCem; Group D, self cured, RelyX Aplicap） were prepared according to their manufacture recommendation. Changes in color and translucency of test samples were determined before and after UV aging for 8, 16 and 24 hour using the CIE L* a* b* system by a colorimeter. The results were analyzed by LSD multi -compare tests. Results The color changes of composite resin cement disks suffering UV aging were significantly different when irradiated different time. For the same irradiated time, Group C had the highest delta E, and Group B and D had the smaller ones. Translucency was found no difference among different irradiated time for group A, B and D. Translucency of group C decreased after UV aging. Conclusion Translucency  0f composite resin cement kept stable after UV aging, and color coordinate changed after UV aging.