具有再矿化和抗菌能力的新型低收缩应力纳米复合材料，可在生物膜下保护边缘釉质。

Novel low-shrinkage-stress nanocomposite with remineralization and antibacterial abilities to protect marginal enamel under biofilm.

机构信息

Ph.D. Program in Dental Biomedical Sciences, Biomaterials and Tissue Engineering Division, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Pediatric Dentistry, Faculty of Dentistry, King AbdulAziz University, Jeddah 21589, Saudi Arabia.

Volpe Research Center, American Dental Association Foundation, Frederick, MD 21704, USA.

出版信息

J Dent. 2020 Aug;99:103406. doi: 10.1016/j.jdent.2020.103406. Epub 2020 Jun 8.

DOI:10.1016/j.jdent.2020.103406

PMID:32526346

Abstract

OBJECTIVES

Polymerization shrinkage stress may lead to marginal damage, microleakage and failure of composite restorations. The objectives of this study were to : (1) develop a novel nanocomposite with low-shrinkage-stress, antibacterial and remineralization properties to reduce marginal enamel demineralization under biofilms; (2) evaluate the mechanical properties of the composite and calcium (Ca) and phosphate (P) ion release; and (3) investigate the cytotoxicity of the new low-shrinkage-stress monomer in vitro.

METHODS

The low-shrinkage-stress resin consisted of urethane dimethacrylate (UDMA) and triethylene glycol divinylbenzyl ether (TEG-DVBE), and 3 % dimethylaminohexadecyl methacrylate (DMAHDM) and 20 % calcium phosphate nanoparticles (NACP) were added. Mechanical properties, polymerization shrinkage stress, and degree of conversion were evaluated. The growth of Streptococcus mutans (S. mutans) on enamel slabs with different composites was assessed. Ca and P ion releases and monomer cytotoxicity were measured.

RESULTS

Composite with DMAHDM and NACP had flexural strength of 84.9 ± 10.3 MPa (n = 6), matching that of a commercial control composite. Adding 3 % DMAHDM did not negatively affect the composite ion release. Under S. mutans biofilm, the marginal enamel hardness was 1.2 ± 0.1 GPa for the remineralizing and antibacterial group, more than 2-fold the 0.5 ± 0.07 GPa for control (p < 0.05). The polymerization shrinkage stress of the new composite was 40 % lower than that of traditional composite control (p < 0.05). The new monomers had fibroblast viability similar to that of traditional monomer control (p > 0.1).

CONCLUSION

A novel low-shrinkage-stress nanocomposite was developed with remineralizing and antibacterial properties. This new composite is promising to inhibit recurrent caries at the restoration margins by reducing polymerization stress and protecting enamel hardness.

摘要

目的

聚合收缩应力可能导致边缘损伤、微渗漏和复合修复体失效。本研究的目的是：(1)开发一种具有低收缩应力、抗菌和再矿化性能的新型纳米复合材料，以减少生物膜下釉质脱矿；(2)评估复合材料的机械性能和钙(Ca)和磷(P)离子释放；(3)研究新型低收缩应力单体的体外细胞毒性。

方法

低收缩应力树脂由尿烷二甲基丙烯酸酯(UDMA)和三乙二醇二乙烯基苄基醚(TEG-DVBE)组成，并添加3%二甲基氨基己基甲基丙烯酸酯(DMAHDM)和20%磷酸钙纳米颗粒(NACP)。评估了机械性能、聚合收缩应力和转化率。评估了不同复合材料对釉质板上变形链球菌(S. mutans)生长的影响。测量了 Ca 和 P 离子释放和单体细胞毒性。

结果

含有 DMAHDM 和 NACP 的复合材料的抗弯强度为 84.9±10.3 MPa(n=6)，与商业对照复合材料相当。添加 3% DMAHDM 不会对复合材料的离子释放产生负面影响。在变形链球菌生物膜下，再矿化和抗菌组的釉质边缘硬度为 1.2±0.1 GPa，是对照组的 0.5±0.07 GPa 的两倍多(p<0.05)。新型复合材料的聚合收缩应力比传统复合材料对照低 40%(p<0.05)。新型单体的成纤维细胞活力与传统单体对照相似(p>0.1)。