Objective

Formulate experimental adhesives containing titanium dioxide nanotubes (nt-TiO₂) or titanium dioxide nanotubes with a triazine-methacrylate monomer (nt-TiO₂:TAT) and evaluate the effect of these fillers on the physical, chemical, and biological properties of the adhesives.

Methods

First, nt-TiO₂ were synthesized via a hydrothermal method. The nt-TiO₂ were mixed with a triazine-methacrylate monomer (TAT) to formulate nt-TiO₂:TAT, which were characterized by transmission electron microscopy (TEM). The nt-TiO₂, TAT, and nt-TiO₂:TAT were evaluated via Fourier Transform Infrared, Ultraviolet–visible, and micro-Raman spectroscopies. An experimental adhesive resin was formulated with bisphenol A glycerolate dimethacrylates, 2-hydroxyethyl methacrylate, and photoinitiator/co-initiator system. nt-TiO₂ or nt-TiO₂:TAT were incorporated at 2.5 wt.% and 5 wt.% in the adhesive. The base resin without nt-TiO₂ or nt-TiO₂:TAT was used as a control group. The adhesives were evaluated for antibacterial activity, cytotoxicity, polymerization kinetics, degree of conversion (DC), Knoop hardness, softening in solvent (ΔKHN%), ultimate tensile strength (UTS), 24 h- and 1 year- microtensile bond strength (μ-TBS).

Results

TEM confirmed the nanotubular morphology of TiO₂. FTIR, UV–vis, and micro-Raman analyses showed the characteristic peaks of each material, indicating the impregnation of TAT in the nt-TiO₂. Adhesives with nt-TiO₂:TAT showed antimicrobial activity against biofilm formation compared to control (p < 0.05), without differences in the viability of planktonic bacteria (p > 0.05). All groups showed high percentages of pulp cell viability. The polymerization kinetics varied among groups, but all presented DC above 50%. The addition of 5 wt.% of nt-TiO₂ and both groups containing nt-TiO₂:TAT showed higher values ​​of Knoop hardness compared to the control (p < 0.05). The groups with nt-TiO₂:TAT presented lower ΔKHN% (p < 0.05) and higher UTS (p < 0.05) than the control group. After one year, the group with 5 wt.% of nt-TiO₂, as well as both groups containing nt-TiO₂:TAT, showed higher μ-TBS than the control (p < 0.05).

Significance

The mixing of a triazine-methacrylate monomer with the nt-TiO₂ generated a filler that improved the physicochemical properties of the adhesive resins and provided antibacterial activity, which could assist in preventing carious lesions around tooth-resin interfaces. The set of physical, chemical, and biological properties of the formulated polymer, together with the greater stability of the bond strength over time, make nt-TiO₂:TAT a promising filler for dental adhesive resins.

中文翻译：

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含甲基丙烯酸三嗪单体的二氧化钛纳米管可改善胶粘剂的理化和生物学特性

目的

配制包含二氧化钛纳米管（nt-TiO ₂）或二氧化钛纳米管与三嗪-甲基丙烯酸酯单体（nt-TiO ₂：TAT）的实验粘合剂，并评估这些填料对粘合剂的物理，化学和生物学特性的影响。

方法

首先，通过水热法合成nt-TiO ₂。将nt-TiO ₂与甲基丙烯酸三嗪单体（TAT）混合，制成nt-TiO ₂：TAT，通过透射电子显微镜（TEM）对其进行表征。nt-TiO ₂，TAT和nt-TiO ₂：TAT通过傅立叶变换红外光谱，紫外可见光谱和显微拉曼光谱进行了评估。用双酚A甘油酸酯二甲基丙烯酸酯，甲基丙烯酸2-羟乙酯和光引发剂/共引发剂体系配制实验性粘合树脂。将nt-TiO ₂或nt-TiO ₂：TAT以2.5重量％和5重量％的量掺入到粘合剂中。没有nt-TiO ₂或nt-TiO的基础树脂₂：TAT用作对照组。评估了粘合剂的抗菌活性，细胞毒性，聚合动力学，转化度（DC），努氏硬度，溶剂软化度（ΔKHN％），极限拉伸强度（UTS），24 h和1年微拉伸强度（μ -TBS）。

结果

TEM证实了TiO ₂的纳米管形貌。FTIR，UV-vis和显微拉曼分析显示每种材料的特征峰，表明TAT在nt-TiO _2中的浸渍。与对照组相比，具有nt-TiO ₂：TAT的胶粘剂显示出对生物膜形成的抗菌活性（p <0.05），而浮游细菌的活力没有差异（p> 0.05）。所有组均显示出高百分比的牙髓细胞活力。各组之间的聚合动力学不同，但是所有的DC均高于50％。与对照组相比，加入5 wt。％的nt-TiO ₂和两组都含有nt-TiO ₂：TAT的努氏硬度值更高（p <0.05）。nt-TiO ₂的基团：TAT比对照组的ΔKHN％低（p <0.05），UTS较高（p <0.05）。一年后，含5％nt-TiO _2的组以及含nt-TiO ₂：TAT的组均显示出比对照组更高的μ-TBS（p <0.05）。

意义

三嗪甲基丙烯酸酯单体与nt-TiO _2的混合产生了一种填充物，该填充物改善了粘合树脂的物理化学性能并提供了抗菌活性，可以帮助防止牙齿树脂界面周围的龋齿。所配制聚合物的一系列物理，化学和生物学特性，以及随着时间的推移粘结强度的更大稳定性，使nt-TiO ₂：TAT成为牙科粘合剂树脂的有希望的填料。