Objectives

This is a confirmatory study to evaluate the effect of photoinitiator type and concentration, matrix monomer chemical structure, and nanoparticle incorporation on the physical and mechanical properties of an experimental dentin bonding agent.

Materials and methods

Different concentrations of camphorquinone-amine (CQ-A) system, butanedione (BD), and phenylpropanedione (PPD), as photoinitiator, BTDMA, as a comonomer containing carboxylic acid groups, and silica nanoparticles as reinforcing inorganic filler were incorporated into a methacrylate base experimental dental adhesive. The effect of these ingredients, as independent variables, on the shrinkage kinetics, flexural strength and modulus, and microshear bond strength of the adhesives were then investigated. The results were analyzed using one-way ANOVA and Tukey’s post-hoc test at the significance level of 0.05.

Results

The results indicate that the efficiency of CQ-A initiator system is diminished in the presence of the acidic monomer BTDMA while the photopolymerization is efficiently progressed with BD as initiator. PPD shows the lowest efficiency in the photopolymerization of the adhesives. BTDMA as a monomer with the capability of interaction with tooth structure provides adhesive with improved microshear bond strength to dentin. Incorporation of silica nanoparticles at low concentrations enhances the flexural and microshear strength of the dentin bonding agent.

Significance

Understanding the structure–property relationship in dental adhesives may help the material selection in clinical dentistry. The study elucidates the relationship between monomer structure, initiator type, and nanofiller and physical and mechanical properties in dental adhesives.

中文翻译：

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牙科胶粘剂中结构与性能的关系：引发剂，基质单体结构和纳米填料掺入的影响

目标

这是一项验证性研究，旨在评估光引发剂类型和浓度，基质单体化学结构以及纳米颗粒掺入对实验性牙本质粘合剂的物理和机械性能的影响。

材料和方法

将不同浓度的樟脑醌-胺（CQ-A）体系，丁二酮（BD）和苯丙二酮（PPD）作为光引发剂，BTDMA（作为含羧酸基团的共聚单体）和二氧化硅纳米粒子作为增强无机填料，掺入甲基丙烯酸酯基料中实验牙科用粘合剂。然后研究了这些成分（作为独立变量）对粘合剂的收缩动力学，弯曲强度和模量以及微剪切粘合强度的影响。使用单向方差分析和Tukey事后检验以0.05的显着性水平分析结果。

结果

结果表明，在酸性单体BTDMA的存在下，CQ-A引发剂体系的效率降低，而以BD为引发剂有效地进行了光聚合。PPD在粘合剂的光聚合反应中显示出最低的效率。BTDMA作为具有与牙齿结构相互作用能力的单体，为胶粘剂提供了改善的与牙本质的微剪切粘结强度的粘合剂。以低浓度掺入二氧化硅纳米颗粒可增强牙本质粘合剂的弯曲强度和微剪切强度。

意义

了解牙科用胶粘剂的结构与属性之间的关系可能有助于临床牙科中的材料选择。该研究阐明了牙科用粘合剂中单体结构，引发剂类型和纳米填料与物理和机械性能之间的关系。