Resin-dentin bond stability of etch-and-rinse adhesive systems with different concentrations of MMP inhibitor GM1489

Abstract Enzymatic degradation of the hybrid layer can be accelerated by the activation of dentin metalloproteinases (MMP) during the bonding procedure. MMP inhibitors may be used to contain this process. Objective To evaluate the degree of conversion (DC%), dentin bond strength (µTBS) (immediate and after 1 year of storage in water), and nanoleakage of an experimental (EXP) and a commercial (SB) adhesive system, containing different concentrations of the MMP inhibitor GM1489: 0, 1 µM, 5 µM and 10 µM. Methodology DC% was evaluated by FT-IR spectroscopy. Dentin bond strength was evaluated by µTBS test. Half of beams were submitted to the µTBS test after 24 h and the other half, after storage for 1 year. From each tooth and storage time, 2 beams were reserved for nanoleakage testing. Data were analyzed using ANOVA and Tukey’s test to compare means (α=0.05). Results All adhesive systems maintained the µTBS after 1 year of storage. Groups with higher concentrations of inhibitor (5 µM and 10 µM) showed higher µTBS values than groups without inhibitor or with 1 µM. The nanoleakage values of all groups showed no increase after 1 year of storage and values were similar for SB and EXP groups, in both storage periods. The inhibitor did not affect the DC% of the EXP groups, but the SB5 and SB10 groups showed higher DC% values than those of SB0 and SB1. Conclusions The incorporation of GM1489 in the adhesive systems had no detrimental effect on DC%. The concentrations of 5 µM GM1489 for SB and 5 µM or 10 µM for EXP provided higher μTBS than groups without GM1489, in the evaluation after 1 year of storage; whereas the concentration of inhibitor did not affect adhesive systems nanoleakage.

摘要：粘接操作过程中，牙本质基质金属蛋白酶（MMP）的激活可加速混合层的酶促降解，而MMP抑制剂可用于抑制该过程。
目的：本研究旨在评估添加不同浓度（0、1 µM、5 µM、10 µM）MMP抑制剂GM1489的实验型（EXP）与商用型（SB）粘接系统的转化率（DC%）、牙本质粘接强度（µTBS，包含即刻粘接强度及水存储1年后的粘接强度）以及纳米渗漏情况。
方法：采用傅里叶变换红外光谱法评估转化率（DC%），通过µTBS测试评估牙本质粘接强度。将一半试样条在24小时后进行µTBS测试，另一半经水存储1年后再开展测试。从每颗牙齿的各存储时间组中各预留2根试样条用于纳米渗漏测试。采用方差分析（ANOVA）与Tukey检验对各组均值进行比较，显著性水平设定为α=0.05。
结果：所有粘接系统经水存储1年后，其µTBS均保持稳定。抑制剂浓度较高的组（5 µM与10 µM组）的µTBS值显著高于无抑制剂组或1 µM抑制剂组。所有组别经1年水存储后，纳米渗漏值均未出现升高，且在两个存储时间点，SB组与EXP组的纳米渗漏值均无显著差异。抑制剂对EXP组的DC%无显著影响，但SB5与SB10组的DC%值显著高于SB0及SB1组。
结论：在粘接系统中添加GM1489不会对DC%产生不利影响。经1年水存储后的评估显示，SB组添加5 µM GM1489、EXP组添加5 µM或10 µM GM1489时，其µTBS均高于未添加GM1489的对应组别；而抑制剂浓度对粘接系统的纳米渗漏无显著影响。