Breschi Lorenzo, Cadenaro Milena, Antoniolli Francesca, Visintini Erika, Toledano Manuel, Di Lenarda Roberto
Division of Dental Sciences and Biomaterials, Department of Biomedicine, University of Trieste, Italy.
Am J Dent. 2007 Aug;20(4):275-80.
To analyze the extent of polymerization of four adhesive systems on whitened enamel immediately after bonding or delayed for 24 hours and 2 weeks. The effect of prolonged light-curing was also analyzed.
One adhesive of each class was investigated: Adper Scotchbond Multi-Purpose (three-step etch-and-rinse), One-Step (two-step etch-and-rinse), Clearfil Protect Bond (two-step self-etching) and Xeno III (one-step self-etching). Enamel fragments were treated with Opalescence Xtra Boost for 30 minutes, powdered and pressed into aluminum pans. Specimens were bonded immediately after bleaching, after 24 hours or after 14 days of storage in 100% humidity at 37 degrees C. Unbleached enamel powder was prepared as control. Extent of polymerization of bonded interfaces was obtained with differential scanning calorimetry (DSC) at 20, 40 and 60 seconds and data were statistically analyzed with 3-way ANOVA and Tukey's post-hoc test.
The extent of polymerization obtained from DSC exotherms of adhesives applied immediately after bleaching was significantly lower compared to controls. Increased extent of polymerization after storage was confirmed for all adhesives and no difference with controls was found after 14 days. Prolonged irradiation time increased curing rate for all the tested adhesives. This study supported the hypothesis that polymerization of the adhesive is reduced after enamel bleaching and delayed adhesive application reverses the polymerization inhibition. Prolonged polymerization intervals may counteract the inhibition of polymerization due to the bleaching procedure; nevertheless further clinical studies should validate this hypothesis.
分析四种粘接系统在美白釉质上粘接后即刻、延迟24小时和2周时的聚合程度。同时分析延长光固化时间的影响。
对每类中的一种粘接剂进行研究：Adper Scotchbond多用途粘接剂（三步酸蚀冲洗型）、一步法粘接剂（两步酸蚀冲洗型）、Clearfil Protect Bond（两步自酸蚀型）和Xeno III（一步自酸蚀型）。用Opalescence Xtra Boost对釉质碎片处理30分钟，磨成粉末并压入铝盘中。在漂白后即刻、24小时后或在37℃、100%湿度下储存14天后进行粘接。制备未漂白的釉质粉末作为对照。在20、40和60秒时用差示扫描量热法（DSC）获得粘接界面的聚合程度，并采用三因素方差分析和Tukey事后检验对数据进行统计学分析。
与对照组相比，漂白后即刻应用粘接剂的DSC放热曲线得到的聚合程度显著降低。所有粘接剂在储存后聚合程度均增加，14天后与对照组无差异。延长照射时间提高了所有测试粘接剂的固化速率。本研究支持以下假设：釉质漂白后粘接剂的聚合减少，延迟应用粘接剂可逆转聚合抑制。延长聚合时间间隔可能抵消漂白过程对聚合的抑制作用；然而，进一步的临床研究应验证这一假设。
