自粘接树脂水门汀在模拟根管内的硬度变化

Hardness development of self-adhesive resin cement in simulated root canal

目的比较自粘接与通用型树脂水门汀在模拟根管内固化开始后的硬度变化。方法将双重固化自粘接树脂水门汀A(RelyX Unicem)、B(BisCem)和双重固化通用型树脂水门汀C(DUOLINK)注满单端开口、以盖板封闭的半圆柱形不锈钢槽,将光固化灯紧贴开口端持续照射20 s,试件避光保存0.5 h后打开封闭盖板,测量树脂纵断面距照射光源1～10 mm间,以1 mm为间隔共10个深度的努氏显微硬度。试件继续避光保存24、120 h后,重复上述测量。对测量数据进行统计学分析。结果 3种材料的硬度值随模拟根管深度的增加而降低(P<0.001),其中A组在5 mm及以下各深度的硬度值、B和C组在4mm及以下各深度的硬度值差异无统计学意义。各组的硬度值在固化开始后0.5h内增长最多,24 h后硬度值达到或接近最大值。光照后120 h,除1 mm深处外,C组在各深度的硬度值均显著高于A和B组(P<0.001)。结论 2种类型树脂水门汀双重固化条件下的硬度值差异有统计学意义,但随时间变化的趋势基本一致。

Objective To compare the hardness development of dual-cured self-adhesive and universal resin cement in simulated root canal.Methods The light-proof half-cylinder steel slot with one end open were syringed and filled respectively by self-adhesive A（RelyX Unicem）,B（BisCem） and universal C（DUOLINK） resin cements,then the open end of slot was irradiated directly by a light unit for 20 s.Specimens were stored in a light-proof box for 0.5 h,Knoop microhardness was measured along the vertical surfaces of specimens from 1 mm to 10 mm depth at 1 mm intervals.The same measurements were taken at 24 h and 120 h after irradiation.Data were analyzed by One-way ANOVA.Results Hardness of each group decreased with the increase of simulated canal depth（P0.001）,however hardness showed no significant change between 5 mm and more depth of group A,between 4 mm and more depth of group B and C.The increase of hardness for each group was more rapid within 0.5 h after irradiation,thereafter the hardness increased gra-dually to maximum at 24 h.At 120 h after irradiation,hardness of group C was greater than that of other two groups at more than 1 mm depth（P0.001）.Conclusion Under dual-cured condition,hardness has significant difference between self-adhesive and universal resin cements,however their hardness development is similar.