Chitosan-Based Extrafibrillar Demineralization for Dentin Bonding
Chitosan-Based Extrafibrillar Demineralization for Dentin Bonding
复制标题
基于壳聚糖的纤维外脱矿用于牙本质粘接
DOI：
10.1177/0022034518805419
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发表时间：
2019-02-01
影响因子：
7.6
通讯作者：
Niu, L. N.
中科院分区：
文献类型：
--
作者：
Gu, L. S.;Cai, X.;Niu, L. N.
树脂-牙本质粘结的不稳定性是粘接牙科的致命弱点。为了解决这个问题，已经开发了螯合和冲洗的纤维外牙本质脱矿策略，其保持胶原纤维内的纤维内矿物质完整，以防止导致混合层内胶原降解的内源性蛋白酶的激活。本研究的目的是评估使用>40 kDa的壳聚糖作为抗微生物纤维外牙本质螯合剂以增强粘结耐久性的潜力。透射电子显微镜提供的证据保留原纤维内的矿物质和涂抹塞在牙本质条件与1重量%的壳聚糖。经Kruskal-Wallis方差分析、Dunn统计量和Mann-Whitney检验，结果表明，与磷酸酸蚀相比，壳聚糖螯合牙本质60 s后，树脂-牙本质粘结强度无显著性下降（P > 0.05）。明胶分解活性的混合层内进行了检查，通过原位酶谱后24小时的存储或热机械循环后，并与3-因素方差分析。24 h后，仅在完全脱矿的磷酸酸蚀牙本质中检测到酶活性，干粘接的酶活性显著高于湿粘接的酶活性（P < 0.05）。与对照组相比，当用壳聚糖处理牙本质时，即使在热机械循环后，在混合层内检测到可忽略的荧光。由于涂抹塞保留，壳聚糖处理的牙本质的水渗透性降低，也促进了长期的粘结稳定性。用活/死染色法进行的抗菌试验表明，乙酸溶解的壳聚糖对3种单种生物膜具有抗菌活性：变形链球菌、内氏放线菌和粪肠球菌。总之，新的基于壳聚糖的纤维外脱矿策略保留了纤维内矿物质，减少了内源性蛋白酶引发的胶原蛋白降解，防止了混合层内的水渗透，并杀死了牙本质表面上的细菌，这是增强树脂-牙本质粘结耐久性的关键因素。
Instability of resin-dentin bonds is the Achilles' heel of adhesive dentistry. To address this problem, a chelate-and-rinse extrafibrillar dentin demineralization strategy has been developed that keeps intrafibrillar minerals within collagen fibrils intact to prevent activation of endogenous proteases that are responsible for collagen degradation within hybrid layers. The objective of the present study was to evaluate the potential of using chitosan >40 kDa as an antimicrobial extrafibrillar dentin-chelating agent to enhance bond durability. Transmission electron microscopy provided evidence for retention of intrafibrillar minerals and smear plugs in dentin conditioned with 1 wt% chitosan. Analyzed by Kruskal-Wallis analysis of variance, Dunn's statistic, and separate Mann-Whitney tests, tensile bond strengths to wet- and dry-bonded dentin indicated that chelating dentin with chitosan for 60 s prior to bonding did not result in a significant decline in resin-dentin bond strength when compared with that of phosphoric acid etching (P > 0.05). Gelatinolytic activity within the hybrid layers was examined via in situ zymography after 24-h storage or after thermomechanical cycling and analyzed with 3-factor analysis of variance. After 24 h, enzymatic activity was detected only within completely demineralized phosphoric acid-etched dentin, with values derived from dry bonding significantly higher than those derived from wet bonding (P < 0.05). Negligible fluorescence was detected within hybrid layers when dentin was conditioned with chitosan, even after thermomechanical cycling, as compared with the controls. Reduction in water permeability in chitosan-conditioned dentin, attributed to smear plug retention, also fostered long-term bond stability. Antibacterial testing performed with live/dead staining indicated that the acetic acid-solubilized chitosan possessed antibacterial activities against 3 single-species biofilms: Streptococcus mutans, Actinomyces naeslundii, and Enterococcus faecalis. Taken together, the new chitosan-based extrafibrillar demineralization strategy retains intrafibrillar minerals, reduces endogenous protease-initiated collagen degradation, prevents water permeation within hybrid layers, and kills bacteria on dentin surfaces, which are crucial factors for enhancing resin-dentin bond durability.