胶原交联增加了其在湿润牙本质粘结中的生物降解抗性。
Collagen cross linking increases its biodegradation resistance in wet dentin bonding.
机构信息
University of Missouri-Kansas City, School of Dentistry, Kansas City, MO 64108, USA.
出版信息
J Adhes Dent. 2012 Feb;14(1):11-8. doi: 10.3290/j.jad.a21494.
PURPOSE
The biodegradation of exposed dentin collagen within the adhesive/dentin (a/d) interface is one of the main reasons for composite restoration failures and seriously affects the durability of dental restorations. In the present study, the objective was to investigate whether the inclusion of the cross-linking reagent (glutaraldehyde, GA) in the adhesive would increase collagen biodegradation resistance within the a/d interface.
MATERIALS AND METHODS
The model adhesive consisted of ~60 % monomers (HEMA/bis-GMA, 45/55 wt/wt) and ~ 40 % ethanol as a solvent. 5% GA was added to the above formulation. After the dentin surfaces were etched for 15 s with 35% phosphoric acid, rinsed with water and blotted dry, adhesives both with and without GA were applied and polymerized by visible light for 20 s. These a/d specimens were immersed in the biodegradation solution (prepared by adding 160 mg collagenase in 1 liter of TESCA buffer solution) for up to 30 days after proceeding with the sectioning/fracture to expose the a/d interfaces. The specimens were analyzed using SEM and micro-Raman spectroscopy.
RESULTS
SEM results indicated that for the adhesive without GA, there were many voids and a loss of collagen fibrils in the a/d interface after being challenged by the biodegradation solution. The Raman spectra collected from the interface showed that the amide I of collagen at 1667 cm-1 obviously decreased, indicating a removal of collagen fibrils during the degradation process. For the adhesive containing GA, the collagen fibrils within the interface did not degrade at all, which was also confirmed by the Raman results.
CONCLUSION
The results corroborate the previous findings that by using the current adhesive system and wet bonding, the collagen fibrils in the a/d interface are largely unprotected and easily undergo biodegradation. Directly including cross-linking agents in the adhesive could protect collagen fibrils from degradation in situ within the a/d interface.
目的
暴露于粘结/牙本质（a/d）界面内的牙本质胶原的生物降解是复合树脂修复失败的主要原因之一，严重影响了牙齿修复体的耐久性。本研究旨在探讨粘结剂中是否包含交联剂（戊二醛，GA）会增加 a/d 界面内胶原的生物降解抗性。
材料和方法
模型粘结剂由60%的单体（HEMA/双-GMA，45/55wt/wt）和40%的乙醇作为溶剂组成。上述配方中添加了 5%的 GA。用 35%磷酸酸蚀牙本质表面 15s 后，用清水冲洗并吸干，然后分别涂覆含 GA 和不含 GA 的粘结剂，并用可见光聚合 20s。将这些 a/d 标本在进行切片/断裂以暴露 a/d 界面后，立即将其浸入生物降解溶液（在 TESCA 缓冲溶液中加入 160mg 胶原酶制备）中，最多 30 天。使用 SEM 和微拉曼光谱对标本进行分析。
结果
SEM 结果表明，对于不含 GA 的粘结剂，在生物降解溶液的作用下，a/d 界面中的许多空隙和胶原纤维丢失。从界面采集的拉曼光谱表明，1667cm-1处的胶原酰胺 I 明显减少，表明在降解过程中胶原纤维被去除。对于含有 GA 的粘结剂，界面内的胶原纤维根本没有降解，这也得到了拉曼结果的证实。
结论
研究结果证实了以前的发现，即使用当前的粘结系统和湿粘结，a/d 界面内的胶原纤维基本得不到保护，很容易发生生物降解。直接将交联剂包含在粘结剂中可以保护 a/d 界面内的胶原纤维免受原位降解。
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