微拉伸实验比较MMPs抑制剂对牙本质粘结混合层强度的影响

发布时间：2018-07-22 13:55

【摘要】：微创牙体粘结修复即牙体缺损的直接粘结修复技术是目前国内外广泛应用的治疗方法。牙本质由于其自身的特殊结构，在粘结治疗中仍然存在一定的难度。应用传统的水湿粘结技术可以保持脱矿牙本质中胶原纤维的蓬松，利于树脂单体渗入，但是存在较高的临床技术敏感性，单体析出，胶原纤维的降解均可导致粘结界面的质量下降。牙本质基质中主体成分是I型胶原纤维，与树脂单体通过微机械锁结作用形成牙本质粘结界面混合层（dentin hybrid layer,DHL）,混合层的质量直接影响着粘结效果的好坏，决定粘结强度的高低。牙本质基质中存在着内源性蛋白水解酶，称基质金属蛋白酶（matrix metalloproteinases，MMPs），能降解混合层内暴露的胶原纤维，导致粘结界面老化，粘结效果降低。近年来国内外研究报道多种MMPs抑制剂应用于牙本质树脂粘结界面可以有效延缓混合层的老化，提高粘结强度和耐久性。目的：本实验在全酸蚀水湿粘结技术的基础上，使用Adper Single Bond2体系，应用氯己定(Chlorhexidine,CHX)和米诺环素（Minocycline，MI)作为MMPs抑制剂预处理牙本质粘结界面，通过微拉伸强度测试（Microtensile Bonding Strength，MTBS）和场发射扫描电镜（Field emission in-lens scanning electron microscope，FEISEM）观察断面类型及微观形态，结合10%次氯酸钠溶液（Sodiumhypochlorite，NaOCl）模拟体外粘结界面老化实验，分析不同MMPs抑制剂对牙本质树脂粘结混合层强度及耐久性的影响，为形态学研究及临床提供数据支持，完善效果评价。材料和方法：收集2周内拔除的无龋人磨牙45颗，根据牙本质粘结界面涂布抑制剂的方案不同分为三大组——酸蚀组、CHX组、MI组。各组磨牙去除冠部釉质，暴露牙本质浅层，酸蚀后，预处理牙本质粘结界面，树脂修复，沿粘结面的垂直方向切割成约1×1mm2长条形拉伸测试件，每大组在体视显微镜下选择无缺损无微裂纹试件45个，根据应用10%NaOCl模拟界面老化时间的不同随机分为3个亚组——未老化组、老化5min组、老化10min组，每亚组各15个试件。试件制备完成后进行微拉伸强度测试，统计学进行数据分析，场发射扫描电镜观察断面类型及断裂面微观形态。结果：采用SPSS20.0统计学软件分析数据，在未老化、老化5min、老化10min时，CHX组粘结强度的差异均有统计学意义，均高于对照组（P0.05）；MI组中未老化，老化5min，老化10min时粘结强度均略高于对照组，但是差异均无统计学意义(P0.05)。结论： 1.氯己定作为MMPs抑制剂预处理牙本质粘结界面，可显著提高各时间点牙本质树脂粘结强度，形成的混合层更均匀，树脂渗透更充分，树脂突更粗更长，与牙本质小管结合更为紧密。 2.氯己定对10%NaOCl模拟老化下的粘结混合层存在保护作用，随着老化时间的延长，混合层降解程度较小，减缓MMPs降解胶原纤维，控制粘结界面的老化进展，改善粘结耐久性。 3.米诺环素作为MMPs抑制剂预处理牙本质粘结界面，，对即刻和老化后的牙本质树脂粘结强度有所提高，但无显著性差异。 4.米诺环素对10%NaOCl模拟老化下的粘结混合层保护作用不明显，随着老化时间的延长，混合层退化及胶原纤维降解情况未得到明显改善。因此，米诺环素作为牙本质粘结界面混合层中MMPs抑制剂的研究仍需进一步探讨。
[Abstract]:The technique of direct bonding repair of dental defect with minimally invasive dental prosthesis is a widely used treatment method at home and abroad. Because of its special structure, the dentin still has some difficulty in the bonding treatment. The application of traditional water wet bonding technique can maintain the fluffy of collagen fiber in the dentin of the demineralized tooth and be beneficial to the resin single. The body infiltrates, but there is a high clinical sensitivity. The degradation of the collagen fibers can lead to the degradation of the bonding interface. The main component of the dentin matrix is I collagen fiber, and the dentin bonding interface (dentin hybrid layer, DHL) and the mass of the mixed layer are formed by the micromechanical locking of the resin monomers. There is an endogenous protein hydrolase in dentin matrix, called matrix metalloproteinase (matrix metalloproteinases, MMPs), which can degrade the collagen fibers exposed in the mixed layer, which leads to the aging of the bonding interface and the decrease of bond effect. In recent years, many kinds of MM have been reported at home and abroad. The application of Ps inhibitors to dentin resin bonding interface can effectively delay the aging of the mixed layer, improve the bond strength and durability.
Objective:
On the basis of all acid etching water wet bonding technology, this experiment uses Adper Single Bond2 system, uses chlorhexidine (Chlorhexidine, CHX) and minocycline (Minocycline, MI) as the MMPs inhibitor to pretreat dentin bonding interface, and through the micro tensile strength test (Microtensile Bonding Strength, MTBS) and field emission scanning electron microscope (field emission scanning electron microscopy) N in-lens scanning electron microscope, FEISEM) observation section type and microscopic morphology, combined with 10% sodium hypochlorite solution (Sodiumhypochlorite, NaOCl) simulation in vitro bonding interface aging test, analyze the effect of different MMPs inhibitors on the bond strength and durability of dentin resin bond, and provide data support for morphological study and clinical study. Hold, improve the effect evaluation.
Materials and methods:
A total of 45 dental caries free molars were extracted for 2 weeks. According to the different coating inhibitors of dentin bonding interface, they were divided into three groups: acid corrosion group, CHX group and MI group. The teeth were removed from the crown enamel and exposed to the shallow layer of dentin. After acid etching, the dentin bonding interface was pretreated, the tree fat was repaired and the 1 x 1mm2 was cut along the vertical direction of the adhesive surface. Under the stereoscopic microscope, 45 specimens with no defect and no micro crack were selected under the stereoscopic microscope. According to the different aging time of the 10%NaOCl simulation interface, the specimens were randomly divided into 3 subgroups: the aging group, the aging 5min group, the aging 10min group, and each subgroup of 15 specimens. The microtensile strength test was performed after the preparation was completed, statistics and statistics. Data analysis and field emission scanning electron microscope (SEM) were carried out to observe the type of section and the microstructure of fracture surface.
Result:
SPSS20.0 statistical software was used to analyze the data. The difference of bond strength in group CHX was statistically significant when it was not aging, aging, 5min and aging 10min, all of which were higher than that of the control group (P0.05), and the bond strength of aging 10min in MI group was slightly higher than that in the control group, but the difference was not statistically significant (P0.05).
Conclusion:
1. chlorhexidine, as MMPs inhibitor pretreated dentin bonding interface, can significantly improve the bonding strength of dentin resin at all time points, the mixed layer is more uniform, the resin permeation is more fully, the resin process is thicker and longer, and it is closer to the dentinal tubule.
2. chlorhexidine has protective effect on the bonding layer of 10%NaOCl under simulated aging. With the prolongation of aging time, the degradation degree of the mixed layer is small, and the degradation of collagen fibers by MMPs is slowed down, and the aging progress of the bonding interface is controlled and the adhesion durability is improved.
3. minocycline, as an inhibitor of MMPs, pretreated dentin bond interface, which improved the bonding strength of dentin resin immediately and after aging, but there was no significant difference.
The protective effect of 4. minocycline on the bonding layer of 10%NaOCl under simulated aging is not obvious. As the aging time prolongs, the degradation of mixed layer and the degradation of collagen fiber have not been obviously improved. Therefore, the study of minocycline as a MMPs inhibitor in the mixed layer of dentin bonding interface still needs to be further explored.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R783.3

【共引文献】