Rey Juan Carlos University, Stomatology, Madrid, Spain.
Oper Dent. 2012 Sep-Oct;37(5):548-56. doi: 10.2341/11-079-L. Epub 2012 Feb 15.
To compare the microhardness of several dual-cure, self-adhesive resin cements used to lute fiber posts at 24 hours and seven days after cementation.
Bovine incisors were selected to lute 15 fiber posts that were 12 mm long (FRC Postec Plus size 3, Ivoclar-Vivadent). Five resin cements were tested: Multilink Automix (Ivoclar-Vivadent), without light-curing, and the self-adhesive resin cements Maxcem Elite (Kerr), RelyX Unicem (3M ESPE), G-Cem (GC), and Smartcem 2 (Dentsply), which were light-cured for 40 seconds (LED Bluephase, Ivoclar-Vivadent). Each root was embedded in chemically cured acrylic resin and stored at 37°C for 24 hours. The roots were transversally sectioned into nine specimens that were each 1 mm thick, with three specimens corresponding to each root third. Indentations (100g, 30 seconds) were performed on each section in the resin cement, at 24 hours and seven days after cementation, using a Vickers digital microdurometer (Buehler). Data were analyzed by two-way analysis of variance, Student-Newman-Keuls test, and paired t-test (p<0.05).
A significant influence was found (p<0.05) for the resin cement evaluated, the root third, and their interactions on microhardness values at 24 hours and seven days after post cementation. RelyX Unicem and G-Cem exhibited the highest microhardness values, whereas Multilink Automix presented the lowest. All resin cements suffered a decrease in microhardness according to root canal depth, with the exception of G-Cem and Multilink Automix at 24 hours and Smartcem 2 after seven days. After seven days, the evaluated resin cements showed a significant increase in microhardness values, with the exception of Maxcem Elite and Smartcem 2 at the coronal third.
Microhardness of the self-adhesive resin cements when used to lute fiber posts was material-dependent and higher values were obtained in the coronal third, revealing their sensitivity to light irradiation. More information regarding the polymerization reaction of these cements is warranted. According to the current results, microhardness values were significantly higher one week after post luting.
比较几种双固化自粘接树脂水门汀在粘固纤维桩 24 小时和 7 天后的微硬度。
选择 15 颗 12mm 长的牛切牙粘固 FRC Postec Plus 纤维桩（3 号，义获嘉伟瓦登特）。测试 5 种树脂水门汀：Multilink Automix（义获嘉伟瓦登特），不光照，以及自粘接树脂水门汀 Maxcem Elite（登士柏）、RelyX Unicem（3M ESPE）、G-Cem（GC）和 Smartcem 2（登士柏），光照 40 秒（Ivoclar-Vivadent Bluephase LED）。每个牙根用化学固化丙烯酸树脂包埋，37°C 保存 24 小时。将牙根横切成 9 个 1mm 厚的样本，每个牙根对应 3 个样本。在粘固后 24 小时和 7 天，在每个样本的树脂水门汀上进行 100g，30 秒的维氏硬度压痕测试。使用维氏数字硬度计（Buehler）。数据用双因素方差分析、Student-Newman-Keuls 检验和配对 t 检验（p<0.05）进行分析。
粘固后 24 小时和 7 天，树脂水门汀、牙根第三部分及其相互作用对微硬度值有显著影响（p<0.05）。RelyX Unicem 和 G-Cem 显示出最高的微硬度值，而 Multilink Automix 则显示出最低的微硬度值。所有树脂水门汀的微硬度值均随根管深度而降低，除 G-Cem 和 Multilink Automix 在 24 小时和 Smartcem 2 在 7 天后。7 天后，除 Maxcem Elite 和 Smartcem 2 在冠部第三部分外，所有评估的树脂水门汀的微硬度值均显著增加。
粘固纤维桩时，自粘接树脂水门汀的微硬度值与材料有关，冠部第三部分的微硬度值较高，表明其对光照的敏感性。需要更多关于这些水门汀聚合反应的信息。根据目前的结果，粘固后一周微硬度值显著升高。
