Department of SAU&FAL, University of Bologna, Bologna, Italy.
J Dent. 2011 Jul;39(7):470-7. doi: 10.1016/j.jdent.2011.04.004. Epub 2011 Apr 28.
Degradation of hybrid layers (HLs) within resin-infiltrated dentine results from multiple degradation factors, including collagenolytic activity of specific matrix metalloproteinases (MMPs). Inhibition of host-derived MMPs may, therefore, slow the degradation of HL. The null hypothesis tested is that the presence of MMP-2 is similar regardless of chlorhexidine (CHX) pre-treatment or the use of an adhesive.
Powdered dentine prepared from extracted human teeth was divided into 4 groups: (G1) mineralised powder (control group); (G2) dentine powder treated with 1% phosphoric acid for 1 min; (G3) 1% phosphoric acid-etched dentine treated with Adper Scotchbond 1 XT (SB1XT; 3M ESPE); (G4) 1% phosphoric acid-etched dentine treated with 0.2% CHX followed by SB1XT. The concentration of detectable pro-MMP-2 and MMP-2 was assayed using a colorimetric assay system (QuantiSir). In addition, the presence of MMP-2 in the HL was assessed in 1 year-aged adhesive-dentine interfaces using an immunohistochemical approach under FEI-SEM/TEM.
In dentine powder treated with 1% phosphoric acid (G2), MMP-2 level decreased compared to controls (G1); the application of SB1XT (G3) resulted in an increase of MMP-2, whilst 0.2% CHX before SB1XT application (G4), reduced MMP-2. The FEI-SEM/TEM analysis revealed MMP-2 distribution within the HL of aged interfaces showing increase MMP-2 patterns in the control group and minor labelling in the CHX-pretreated specimens.
The results of this study support the use of non-toxic MMPs inhibitors, such as CHX, as an appropriate additional step in bonding procedures in order to increase the longevity of the adhesive restorations.
混合层（HL）在树脂渗透牙本质内的降解是由多种降解因素引起的，包括特定基质金属蛋白酶（MMPs）的胶原酶活性。因此，抑制宿主来源的 MMPs 可能会减缓 HL 的降解。本研究的零假设是，基质金属蛋白酶-2（MMP-2）的存在无论是否使用氯化己定（CHX）预处理或使用黏结剂，其情况都相似。
从人牙中提取的牙本质粉末分为 4 组：（G1）矿化粉末（对照组）；（G2）用 1%磷酸处理 1 分钟的牙本质粉末；（G3）用 1%磷酸蚀刻牙本质并用 Adper Scotchbond 1 XT（SB1XT；3M ESPE）处理的牙本质粉末；（G4）用 0.2%CHX 处理并用 SB1XT 处理的 1%磷酸蚀刻牙本质。使用比色测定系统（QuantiSir）检测可检测的前基质金属蛋白酶-2 和基质金属蛋白酶-2 的浓度。此外，在使用 FEI-SEM/TEM 进行的 FEI-SEM/TEM 分析中，在 1 年老化的黏结-牙本质界面中评估 HL 中 MMP-2 的存在。
在用 1%磷酸处理的牙本质粉末（G2）中，与对照组（G1）相比，MMP-2 水平降低；应用 SB1XT（G3）导致 MMP-2 增加，而在应用 SB1XT 之前应用 0.2%CHX（G4）则降低 MMP-2。FEI-SEM/TEM 分析显示 MMP-2 在老化界面 HL 中的分布，在对照组中显示 MMP-2 模式增加，在 CHX 预处理标本中显示较小的标记。
本研究结果支持使用无毒的 MMPs 抑制剂，如 CHX，作为黏结程序中的适当附加步骤，以增加黏结修复体的使用寿命。
