Graduate student, Beijing Institute of Dental Research, School of Stomatology, Capital Medical University, Beijing, PR China.
Technician, Beijing Institute of Dental Research, School of Stomatology, Capital Medical University, Beijing, PR China.
J Prosthet Dent. 2022 Jul;128(1):100.e1-100.e8. doi: 10.1016/j.prosdent.2022.04.029. Epub 2022 Jun 7.
Polymethyl methacrylate (PMMA) has been widely used for denture base resin. However, concerns associated with PMMA, such as poor mechanical strength, high roughness, and porosity promoting microbial adhesion have been voiced; appropriate modification of PMMA denture base resin may improve its clinical application.
The purpose of this in vitro study was to investigate the effect of zinc dimethacrylate (ZDMA) modification on the mechanical and antibacterial properties of PMMA.
ZDMA at different mass fractions was mixed into PMMA as the experimental group, and unmodified PMMA was the control group. X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), and the degree of conversion (DC%) were applied for characterization. Mechanical properties were measured with the 3-point bend test (n=10). The Streptococcus mutans biofilm model was used to investigate the antibacterial property by using colony-forming unit counts, metabolic activity, live/dead staining, quantitative real-time PCR (qRT-PCR), and SEM (n=5). The cell counting kit (CCK)-8 test was used to evaluate cytotoxicity. Data were subjected to analysis of variance and the post hoc Tukey honestly significant difference test (α=.05).
SEM-EDS and XRD analysis revealed successful ZDMA incorporation into the PMMA matrix. DC% increased with the mass fraction of ZDMA, and no significant differences in DC% values were found among each tested group (P=.554). ZDMA mass fraction at 1 wt%, 2.5 wt%, and 5 wt% enhanced its mechanical properties, but those at 7.5 wt% and 10 wt% were reduced. The results of antibacterial experiments showed that ZDMA-modified PMMA displayed antibiofilm capabilities. Quantitative real-time PCR indicated that the expression levels of tested genes were significantly suppressed and that CCK-8 test indicated no cytotoxicity.
ZDMA-modified PMMA exhibited antibacterial properties without its mechanical properties being affected. ZDMA is a potential metal crosslinking monomer for the modification of PMMA denture base resin.
聚甲基丙烯酸甲酯（PMMA）已广泛用于义齿基托树脂。然而，人们对 PMMA 提出了一些担忧，例如机械强度差、粗糙度高和多孔性促进微生物附着；适当改性 PMMA 义齿基托树脂可能会改善其临床应用。
本体外研究旨在探讨二甲基丙烯酸锌（ZDMA）改性对 PMMA 机械性能和抗菌性能的影响。
将不同质量分数的 ZDMA 混合到 PMMA 中作为实验组，未改性的 PMMA 作为对照组。采用 X 射线衍射（XRD）、扫描电子显微镜-能谱仪（SEM-EDS）和转化率（DC%）进行表征。采用三点弯曲试验（n=10）测量力学性能。采用变形链球菌生物膜模型，通过菌落形成单位计数、代谢活性、死活染色、实时定量 PCR（qRT-PCR）和扫描电子显微镜（SEM）（n=5）来研究抗菌性能。采用细胞计数试剂盒（CCK-8）试验评估细胞毒性。数据采用方差分析和事后 Tukey Honestly Significant Difference 检验（α=.05）进行分析。
SEM-EDS 和 XRD 分析表明 ZDMA 成功掺入 PMMA 基质中。DC%随 ZDMA 质量分数的增加而增加，且各测试组之间的 DC%值无显著差异（P=.554）。质量分数为 1wt%、2.5wt%和 5wt%的 ZDMA 提高了其机械性能，但质量分数为 7.5wt%和 10wt%的 ZDMA 降低了其机械性能。抗菌实验结果表明，ZDMA 改性 PMMA 具有抗生物膜能力。实时定量 PCR 表明，测试基因的表达水平显著受到抑制，CCK-8 试验表明无细胞毒性。
ZDMA 改性 PMMA 具有抗菌性能而不影响其机械性能。ZDMA 是 PMMA 义齿基托树脂改性的潜在金属交联单体。
