Ilie Nicoleta, Ionescu Andrei C, Diegelmann Julia
Department of Conservative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-University, Goethestr. 70, D-80336 Munich, Germany.
Oral Microbiology and Biomaterials Laboratory, Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, via Pascal, 36, 20133 Milano, Italy.
Dent Mater. 2022 Apr;38(4):700-708. doi: 10.1016/j.dental.2022.02.012. Epub 2022 Mar 3.
A current trend to simplify dental restorative procedures is toward using universal chromatic light-cured resin-based composites (RBCs) designed to adapt esthetically to various clinical situations. This study offers a comparative characterization of the mechanical and cytotoxic behavior of such materials that use different techniques to adjust their optical properties (e.g., structural color instead of pigment addition), have different filler systems but are based on a comparable organic matrix.
The structural appearance of the filler systems was assessed by scanning electron microscopy. Various quasi-static and viscoelastic parameters were evaluated at clinically relevant frequencies (0.5-5 Hz) using an instrumented indentation test with a Dynamic Mechanical Analysis (DMA) module. Cytotoxicity on human gingival fibroblasts (HGF-1), when exposed to eluates from tested RBCs specimens (up to one month), was assessed using a WST-1 colorimetric proliferation assay. Multifactor analysis of variance was applied to compare the parameters of interest (Martens, Vickers, and indentation hardness; elastic and total indentation work; creep, indentation depth; storage, loss, and indentation moduli; loss factor; cell viability) between analyzed RBCs, loading frequencies, and eluate age.
Structural particularities of the filler systems are directly reflected in the mechanical behavior of the analyzed materials. Changes in the filler system, necessary to achieve structural color, generally resulted in lower mechanical properties but a better ability to absorb shock. In contrast, the cytotoxicity was comparable.
Based on the performed characterization, universal chromatic RBCs fits in the conventional RBCs class to expect comparable clinical behavior.
当前简化牙科修复程序的趋势是使用通用的彩色光固化树脂基复合材料（RBCs），这些材料旨在在美学上适应各种临床情况。本研究对这类材料的力学和细胞毒性行为进行了比较表征，这些材料采用不同技术来调整其光学性能（例如，结构色而非添加颜料），具有不同的填料系统，但基于类似的有机基质。
通过扫描电子显微镜评估填料系统的结构外观。使用带有动态力学分析（DMA）模块的仪器压痕试验，在临床相关频率（0.5 - 5Hz）下评估各种准静态和粘弹性参数。使用WST - 1比色法增殖试验评估当暴露于测试RBCs标本的洗脱液（长达一个月）时对人牙龈成纤维细胞（HGF - 1）的细胞毒性。应用多因素方差分析来比较分析的RBCs、加载频率和洗脱液老化之间的相关参数（马氏硬度、维氏硬度和压痕硬度；弹性和总压痕功；蠕变、压痕深度；储能模量、损耗模量和压痕模量；损耗因子；细胞活力）。
填料系统的结构特性直接反映在所分析材料的力学行为中。为实现结构色而对填料系统进行的改变通常导致较低的力学性能，但具有更好的减震能力。相比之下，细胞毒性相当。
基于所进行的表征，通用彩色RBCs符合传统RBCs类别，预期具有可比的临床行为。
