Universidade Santo Amaro - Faculdade de Odontologia, 04829-900, São Paulo, Brazil; Instituto de Pesquisas Energéticas e Nucleares IPEN-CNEN/SP, 05508-000, São Paulo, Brazil.
Instituto de Pesquisas Energéticas e Nucleares IPEN-CNEN/SP, 05508-000, São Paulo, Brazil.
Dent Mater. 2019 Jun;35(6):909-918. doi: 10.1016/j.dental.2019.03.004. Epub 2019 Apr 5.
The aim of this study was to develop a composite material with antibacterial activity using MMT loaded with clorhexidine (CHX). For that it was used a BisGMA/TEGDMA matrix and added low concentration of MMT/CHX. The aim was to evaluate the drug release capacity of MMT, and not to provide reinforcement.
Six experimental composites were made with organic matrix of BisGMA/TEGDMA in equal proportions by weight. The composites received organophlizated montmorillonite with or without CHX. The concentrations were 2,5; 5 or 10% by weight. Degree of conversion (DC) was evaluated using FTIR (peak 6165 cm-1; n=5). Specimens for flexural properties (10×2×1mm) were immediate tested (24h). Elastic modulus(E) and flexural strength (FS) was measured using the three point bending test (n=10). Inibition halo was used to test the antibacterial activity against Staphylococcus aureus, Streptococcus mutans, and Porphyromonas gingivalis (n=5 for each bacteria). The inhibition of biofilm formation (BF) was evaluated by inserting polymerized disc of composite in to a culture media colonized with Streptococcus mutans (n=10). The release of CHX was measured using ultraviolet (255nm) for 10 days (n=5). The data of degree of conversion was analysed using Kruskal-Wallis/ Mann-Whitney, and the other variables using two-way ANOVA/Tukey, always considering a global level of significance of 5%.
DC ranged from 71% to 74%. E ranged from 5.7 to 8.1GPa. FS ranged from 61.4 to 74.7MPa. There were no statistical differences among the groups for all the variables. For the three bacteria tested the composites with CHX loaded presented inhibition of growth for all concentration, except for 2,5% that did not inihibited the growth of P. gingivalis. BF was lower for the groups with 10% MMT/CHX, all groups presented BF, even those without CHX loaded. All concentrations presented release off CHX during all the 28 days analyzed.
Within the limitation of this study it can be concluded that: all concentrations tested presented release of CHX and reduced BF. All concentration presented antibacterial activity for the three bacteria tested, except for 2,5% that did not inhibit the growth of P. gingivalis. The presence of MMT with CHX loaded did not interfere in the properties evaluated.
本研究旨在开发一种具有抗菌活性的复合材料，该复合材料使用负载氯己定（CHX）的 MMT。为此，使用 BisGMA/TEGDMA 基质，并添加低浓度的 MMT/CHX。目的是评估 MMT 的药物释放能力，而不是提供增强。
使用 BisGMA/TEGDMA 以相等的重量比例制成 6 种实验性复合材料。复合材料接收有机基质的有机蒙脱土，有无 CHX。浓度分别为 2.5%、5%或 10%（重量）。使用傅立叶变换红外光谱（峰 6165cm-1；n=5）评估转化率（DC）。立即测试用于弯曲性能的试件（10×2×1mm）（n=10）。弹性模量（E）和弯曲强度（FS）使用三点弯曲试验测量（n=10）。抑菌环用于测试金黄色葡萄球菌、变形链球菌和牙龈卟啉单胞菌的抗菌活性（每种细菌 n=5）。通过将聚合的复合盘插入变形链球菌定植的培养基中来评估生物膜形成（BF）的抑制（n=10）。使用紫外线（255nm）测量 10 天内 CHX 的释放（n=5）。转化率数据使用 Kruskal-Wallis/Mann-Whitney 进行分析，其他变量使用双向方差分析/Tukey 进行分析，始终考虑 5%的总体显著性水平。
DC 范围为 71%至 74%。E 范围为 5.7 至 8.1GPa。FS 范围为 61.4 至 74.7MPa。所有变量的组间均无统计学差异。对于测试的三种细菌，负载 CHX 的复合材料在所有浓度下均表现出抑制生长，除了 2.5%的浓度未抑制牙龈卟啉单胞菌的生长。对于负载 10%MMT/CHX 的组，BF 较低，所有组均出现 BF，即使未负载 CHX 的组也是如此。所有浓度在整个 28 天的分析中均释放 CHX。
在本研究的限制范围内，可以得出结论：所有测试浓度均释放 CHX 并减少 BF。所有浓度均表现出对测试的三种细菌的抗菌活性，除了 2.5%的浓度未抑制牙龈卟啉单胞菌的生长。负载 CHX 的 MMT 的存在并未干扰评估的性能。
