龈沟液中基质金属蛋白酶-9含量与正畸牙根吸收相关性的实验研究

目的 探讨龈沟液中基质金属蛋白酶-9(MMP-9)含量与正畸牙根吸收的相关性,为临床诊断牙根吸收寻找简单、灵敏的检测指标.方法 选择5只6月龄的小型猪作为研究对象,以其下颌第一乳侧切牙作为实验牙,通过施加300 g过大拉力建立动物模型.每周提取实验牙的龈沟液,并应用SDS-PAGE,Western Blot和Gel Doc凝胶成像系统定量检测龈沟液中MMP-9含量的改变.同时在第1、2、4、7周将动物处死,制作实验牙的病理切片,观察发生牙根吸收的情况.根据牙根吸收出现的时间将所有实验动物分为未吸收组和吸收组,对其龈沟液中MMP-9含量进行统计学分析.结果 牙齿受力后,龈沟液中的MMP-9含量先升高,在发生牙根吸收的第2周则减少,然后逐渐升高,在第3、4周达高峰后又逐渐减少.牙根吸收组和未吸收组龈沟液中MMP-9含量的差异有显著的统计学意义.结论 龈沟液中的MMP-9参与了正畸源性牙根吸收过程.     

乳牙根生理性吸收的研究现状

乳牙根吸收是一种生理现象,在乳牙的正常替换过程中具有重要意义.本文就乳牙根吸收特点、破牙细胞的结构及其在牙根吸收中的作用以及乳牙根吸收的酶化学特点等研究进展作一综述.     

基质金属蛋白酶在正畸源性牙根吸收中的作用

基质金属蛋白酶是细胞外基质降解的关键酶,参与正畸源性牙根吸收过程.近几年来,对基质金属蛋白酶在牙根吸收过程中的研究逐渐增加.但是酶的确切来源,在牙根吸收中的具体作用,以及它们的调节因素等方面还有许多不了解之处,有待于今后的进一步的研究.本文对正畸源性牙根吸收过程与基质金属蛋白酶的研究结果进行综述.     

实验性牙根吸收组织中基质金属蛋白酶-1及其抑制剂-1的定位表达

目的检测小型猪实验性牙根吸收组织中基质金属蛋白酶(MMP)-1及基质金属蛋白酶抑制剂(TIMP)-1的表达,探讨二者在牙根吸收过程中的作用。方法选用6头小型猪的12颗下颌乳侧切牙,随机分为4组,每组3颗下颌乳侧切牙,分别加力0、0.98、1.96、2.94 N,每2周加力1次。第1次加力后45 d切取标本,应用SABC免疫组化方法检测MMP-1及TIMP-1在根吸收区牙周组织中的定位表达。结果加力0.98、1.96、2.94 N时牙根吸收区牙周组织中MMP-1阳性染色均比不加力强,加力0.98、1.96 N时牙根吸收区牙周组织中TIMP-1阳性染色均比不加力强。结论MMP-1与TIMP-1参与细胞外基质的代谢活动;MMP-1与TIMP-1在根吸收活动中起着重要的作用。     

根管治疗牙正畸加力后根吸收的相关因素研究

目的研究固定正畸治疗对根管治疗牙牙根吸收的影响和相关因素分析。方法选择正畸治疗前口腔内已完善根管治疗牙45例,利用治疗前后的全口曲面断层片,以改良根吸收分级法评估患者治疗前后牙根形态变化,分析正畸治疗对根管治疗后牙根吸收的影响。结果①正畸治疗后根管治疗牙牙根吸收有所增加,差异具有统计学意义（P〈0．001）;②性别是影响正畸治疗后根管治疗牙牙根吸收方程最为显著的因素（P〈0．05）,提示女性发生根吸收的风险大于男性;③正畸治疗后根管治疗牙与对侧活髓牙比较牙根吸收程度的改变差异没有统计学意义（P〉0．05）;④在所观察的样本中,无论根管治疗牙齿与活髓牙均未见3级根吸收。结论根管治疗牙在固定正畸治疗后可能发生一定程度的根吸收改变,但并不比活髓牙的风险更高。     

正畸治疗前后牙根吸收的临床研究

目的 调查正畸治疗前后牙根吸收的临床特征。方法 随机选择至少经过十二个月固定正畸治疗,有清晰可辨的矫治前后全口曲面断层片的病例９６例,用根吸收分级评估法记录每人矫治前后全口牙齿根吸收情况,并统计分析。结果 （１）正畸治疗前８．６％的牙齿存在根吸收,治疗后４１．６％的牙齿有程度不等的根吸收;（２）治疗前的根吸收绝大部分为轻度,治疗后仍以轻度吸收为主,但也有部分中重度吸收;（３）治疗前的根吸收主要在上颌前牙区;治疗后根吸收上下颌没有显著性差异,但前牙明显高于后牙。结论（１）正畸后的根吸收较为常见;（２）大部分正畸过程中的牙根吸收是可接受的;（３）正畸治疗后有一部分牙齿（１．３％）出现重度根吸收,主要分布于上前牙,成为危害患者颜面美观及功能的隐患,应引起足够的重视。     

基质金属蛋白酶-9在兔正畸牙周组织中的表达

目的：观察兔实验性正畸牙齿移动过程中基质金属蛋白酶-9(MMP-9)在牙周组织中的表达。方法：选用体重在2．0kg左右的日本大耳白兔35只，分为正常组与实验1、3、5、7、14、21天组。建立兔正畸牙齿移动模型，对实验标本进行MMP-9免疫组化染色。通过组织学观察，计算机图像分析系统对兔牙周组织中MMP-9的表达变化进行平均灰度分析，比较压力区与张力区的表达变化。结果：在施力1d后牙周组织压力区的MMP-9表达增强，5d后表达达高峰，此时破骨细胞、血管内皮细胞胞浆中MMP-9表达呈强阳性；牙周组织的张力区在施力第3天MMP-9表达略增强，第14天表达达高峰，成骨细胞胞浆中MMP-9的表达此时呈强阳性。结论：正常免牙周组织中存在MMP-9；MMP-9参与了兔实验性正畸牙齿移动牙周组织的改建过程。     

IL-1β在犬牙根吸收组织的表达及其对人牙周膜细胞MMP-1、TIMP-1表达的影响

目的:探讨白细胞介素1(IL-1β)与正畸牙根吸收的关系。方法:建立犬牙根吸收的动物模型,应用PCR半定量检测IL-1βmRNA在根吸收组织与正常根周组织之间表达的差异性。体外培养人牙周膜细胞(hPDLCs),设立IL-1β工作浓度梯度:0.01、0.1、1、10 ng/ml,0 ng/ml为空白对照组,时间梯度:6、12、24 h,分别运用PCR和免疫细胞荧光化学方法检测IL-1β作用下,hPDLCs中MMP-1、TIMP-1表达的变化。结果:犬牙根吸收组织较正常根周组织的IL-1β表达增强。适当剂量的IL-1β可刺激MMP-1的表达增高(P<0.05),抑制TIMP-1的表达(P<0.05)。结论:IL-1β参与牙根吸收过程中的组织反应,其对hPDLCs中MMP-1表达的促进作用和对TIMP-1表达的抑制作用可能是牙根吸收发生的机制之一。     

正畸治疗对根管治疗牙及对侧同名活髓牙根吸收影响的Meta分析

目的    分析正畸治疗对根管治疗牙及对侧同名活髓牙根吸收的影响。方法    计算机检索Cochrane Library、PubMed、Embase、Google Scholar、中国知网、万方等数据库,查找研究根管治疗牙经正畸治疗后牙根吸收情况的相关文献。应用Meta分析比较正畸治疗对根管治疗牙及对侧同名活髓牙根吸收的影响。结果    纳入了10篇相关文献。Meta分析结果发现,正畸治疗患者根管治疗牙根吸收情况与对侧同名活髓牙比较,差异无统计学意义（P > 0.05）。在男性正畸治疗患者中,根管治疗牙牙根吸收量小于对侧同名活髓牙,差异有统计学意义（P < 0.05）;而女性正畸治疗患者两侧牙根吸收量比较,差异无统计学意义（P > 0.05）。正畸治疗方式（拔牙矫治与非拔牙矫治）和牙位（前牙与后牙）对正畸治疗患者根管治疗牙及对侧同名活髓牙根吸收的影响比较,差异均无统计学意义（均P > 0.05）。结论    正畸治疗过程中移动根管治疗后的牙齿是一种相对安全的操作。     

The Expression of MMP—3 and TIMP—1 During Orthodontic Periodontium Remodeling in Rats

目的：观察大鼠正畸牙周组织改建过程中基质金属蛋白酶—3(MMP—3)和金属蛋白酶组织抑制因子—1(TIMP—1)表达的变化，探讨MMP—3及TIMP—1与正畸牙齿移动的关系。方法：在SD成年大鼠上颌右侧第一磨牙与上颌切牙之间安置正畸装置，建立大鼠磨牙移动实验模型。于牙齿移动1、3、5、7、14d后取材分别进行免疫组化染色、图像分析。结果：牙齿移动1d后，牙周组织细胞MMP—3表达增强，5d后MMP—3表达达到高峰，此时破骨细胞脑浆亦呈强阳性表达。以后MMP—3表达有所下降，但仍高于对照组。而TIMP—1于牙齿移动3d后表达开始增强，7d后显著表达。结论：MMP—3及TIMP—1参与了正畸牙周组织改建过程，MMP—3在破骨细胞性骨吸收中起着重要作用。     

Genetic Polymorphism and Expression of Matrix Metalloproteinases and Tissue Inhibitors of Metalloproteinases in Periapical Lesions: Systematic Review

IntroductionRecent studies involving genetic polymorphism and expression have provided information about their role in periapical lesions. This study aimed to evaluate if there is an association between the genetic polymorphism and gene and protein expressions of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in the periapical inflammatory response.MethodsA systematic review was conducted through a rigorous search in electronic databases as well as a hand search. Two reviewers (κ = 0.90) evaluated the studies considering predetermined eligibility criteria, extracted data for interpretation, and finally used the Strengthening the Reporting of the Genetic Association statement to determine the quality of the scientific evidence.ResultsThe initial search identified 251 studies. After excluding the duplicates and applying the eligibility criteria, 15 studies were eligible to be assessed in full. Two studies had grade A and 13 grade B quality according to the Strengthening the Reporting of the Genetic Association and were included. The selected studies showed that the periapical lesion tissue samples had a high concentration of MMPs; moreover, there was an expressive decrease in the concentration of MMPs and TIMPs in patients with periapical lesions after mechanical chemical preparation. In relation to genetic polymorphisms, MMP1, MMP2, MMP3, and MMP8 were associated with a higher risk of periapical lesions. Moreover, MMPs 1, 2, 3, 7, 8, 9, 13, 14, 16, and 25 and TIMP 1, 2, 3, and 4 can play an important role in the progression of periapical lesions.ConclusionsBased on articles with medium to high quality, MMPs and TIMPs are associated with the formation of periapical lesions (PROSPERO number: CDR42018100406).     

Langerhans cells express matrix metalloproteinases 9 and 2 and tissue inhibitors of metalloproteinases 1 and 2 in healthy human gingival tissue and in periodontitis

BACKGROUND: As antigen-presenting cells, Langerhans cells may play an important role in the initiation and maintenance of periodontal disease. This study is the first report that extends our knowledge of the expression of matrix metalloproteinases and their endogenous tissue inhibitors by Langerhans cells in healthy and diseased gingival tissues. METHODS: Single and double immunolabeling procedures were carried out using monoclonal antibodies against CD1a, matrix metalloproteinases 2 and 9, and tissue inhibitors of matrix metalloproteinases 1 and 2, and analyzed by conventional and confocal microscopes. RESULTS: Langerhans cells expressed matrix metalloproteinases 2 and 9, and tissue inhibitors of matrix metalloproteinases 1 and 2 in healthy and diseased gingival tissues. The tissue inhibitors of matrix metalloproteinase-positive Langerhans cells were mainly observed in the upper epithelial layers. Matrix metalloproteinase 9-positive Langerhans cells were observed especially during periodontitis and in the basal epithelial layer or crossing the basement membrane. CONCLUSION: During periodontal disease, changes in the expression of matrix metalloproteinases and their tissue inhibitors by gingival Langerhans cells could be implicated in the migration of the cells towards the connective tissue.     

Determination of Matrix Metalloproteinases in Human Radicular Dentin

Matrix metalloproteinases (MMPs) are present in sound coronal dentin and may play a role in collagen network degradation in bonded restorations. We investigated whether these enzymes can also be detected in root dentin. Crown and root sections of human teeth were powderized, and dentin proteins were extracted by using guanidine-HCl and EDTA. Extracts were analyzed by zymography and Western blotting for matrix metalloproteinases detection. Zymography revealed gelatinolytic activities in both crown and root dentin samples, corresponding to MMP-2 and MMP-9. MMP-2 was more evident in demineralized root dentin matrix, whereas MMP-9 was mostly extracted from the mineralized compartment of dentin and presented overall lower levels. Western blot analysis detected MMP-8 equally distributed in crown and root dentin. Because MMPs are also present in radicular dentin, their contribution to the degradation of resin-dentin bonds should be addressed in the development of restorative strategies for the root substrate.     

Matrix Metalloproteinases,Tissue Inhibitors of Matrix Metalloproteinases,and Inflammation in Cyclosporine A–Induced Gingival Enlargement: A Pilot In Vitro Study Using a Three‐Dimensional Model of the Human Oral Mucosa

Background: It has been suggested that cyclosporine A (CsA) induces gingival enlargement by promoting an increase in the gingival extracellular matrix (ECM). Nonetheless, the variable occurrence of CsA‐induced gingival enlargement in patients receiving this medication indicates a multifactorial pathogenesis. Clinical observations suggest that local inflammation is associated with the development and severity of CsA‐induced gingival enlargement. Therefore, the purpose of this study is to investigate the effects of CsA and inflammation on the production of ECM homeostatic mediators. Methods: The effects of CsA and inflammation (as assessed using interleukin [IL]‐1β) on the secretion of mediators involved in ECM homeostasis were determined using fibroblast monolayers and three‐dimensional (3D) models of the human oral mucosa. Fibroblast monolayers and 3D cultures were treated with CsA alone or in combination with IL‐1β for up to 72 hours, and the secretion of matrix metalloproteinases (MMPs) 1, 2, 3, 8, 9, 10, and 13 and tissue inhibitors of MMPs (TIMPs) 1, 2, and 4 into the culture medium was assessed using enzyme‐linked immunoassay–based antibody arrays. Results: Fibroblast monolayers responded to CsA with no changes in the secretion of ECM mediators. Conversely, 3D cultures responded to CsA treatment with a reduction in MMP‐10 secretion. IL‐1β alone triggered higher secretory levels of MMPs in both fibroblast monolayers (MMP‐3 and MMP‐10) and 3D cultures (MMP‐9 and MMP‐10). Importantly, fibroblast monolayers and 3D cultures treated with a combination of IL‐1β and CsA showed a decrease in the MMP‐1/TIMP‐1 ratio. Conclusions: These data support the hypothesis that inflammation may alter the pathogenesis of CsA‐induced gingival enlargement by promoting a synergistic decrease in the MMP‐1/TIMP‐1 ratio.     

Ovariectomy Exacerbates Apical Periodontitis in Rats with an Increase in Expression of Proinflammatory Cytokines and Matrix Metalloproteinases

Introduction

The aim of this study was to evaluate the gene expression of proinflammatory cytokines, matrix metalloproteinases (MMPs), and cathepsin K in apical periodontitis (AP) and the volume of lesions in ovariectomized and sham-operated rats.

Matrix metalloproteinases: do they play a role in mucosal pathology of the oral cavity?

Matrix metalloproteinases (MMPs) are critical factors in maintaining the integrity of mucosa and mediating normal biological processes. An imbalance between tissue levels of these mediators and their natural inhibitors is believed to underlie the pathophysiology of many diseases, including those affect the gastrointestinal and oral mucosae. The ongoing development of synthetic inhibitors of these mediators may provide opportunities to develop treatment modalities for patients suffering from these diseases. Understanding the role of MMPs in the pathophysiology of many diseases, however, is far from complete, and the improvement of pharmaceutical management strategies can only be achieved if the underlying process of these diseases is completely comprehended. This paper reviews the functions of matrix metalloproteinases and addresses their role in mediating mucosal pathologies with emphasis on oral mucosa.     

基质金属蛋白酶对牙本质粘接耐久性的影响

基质金属蛋白酶(MMP)是一组分解细胞外基质的钙锌离子依赖型蛋白酶的总称。牙本质粘接剂酸性环境可以激活MMP酶原,进而分解暴露的胶原纤维,破坏粘接界面而导致粘接的失败。抑制MMP可有效增加粘接耐久性。本文就MMP在粘接过程中的激活和对粘接耐久性的影响以及MMP抑制剂的研究进展作一综述。     

基质金属蛋白酶在牙髓病中作用的研究进展

基质金属蛋白酶在牙髓组织细胞外基质代谢过程中发挥着关键性作用，是牙髓病过程中组织损伤机制中的重要因子，其基因表达、蛋白质合成以及活性的表达受到多种因素的调节，对基质金属蛋白酶的研究可以为牙髓病的治疗提供新思路。