Department of Operative Dentistry, Postgraduate Program in Dentistry, Universidade Paulista, Rua Dr. Bacelar, 1212, São Paulo, SP 04026-002, Brazil.
School of Dentistry, Faculdades Metropolitanas Unidas, Av. Santo Amaro, 1239, São Paulo, SP 04505-002, Brazil.
J Dent. 2018 Oct;77:66-71. doi: 10.1016/j.jdent.2018.07.010. Epub 2018 Jul 17.
To evaluate the antibacterial effects, cytotoxicity and microtensile bond strength of an adhesive containing low concentrations of silver nanoparticles (NAg).
Various concentrations of NAg (50, 100, 150, 200 and 250 ppm) were incorporated into the primer of the Scotchbond Multi-Purpose adhesive system (SBMP). Antibacterial activity was examined using a broth microdilution assay to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), agar diffusion assay and the MTT assay was used to examine the biofilm metabolic activity (S. mutans). The Microtensile Bond Test (μTBS) was performed after 24 h, followed by 6-months storage in distilled water. Cytotoxicity was assessed with an MTT reduction assay in human dental pulp stem cells viability after exposure to Nag-conditioned culture media during 0, 24, 48, and 72 h. The results were statistically analyzed (α ≤ 0.05).
MIC was found between NAg 25 and 50 ppm MBC was determined at 50 ppm of NAg. Bacterial activity inhibition was higher than control in all NAg groups compared to control in agar diffusion assay. Biofilm inhibition was statistically higher in 250 ppm NAg than control. All NAg groups and SBMP presented similar cytotoxicity in each period. Adhesives with NAg 200 and 250 ppm and SBMP (control) presented the highest μTBS values, similar to that of SBMP control, in both instances (24 h and 6 months) (p > 0.05).
The commercial primer containing NAg 250 ppm showed both antibacterial effect and reliable bond strength with no cytotoxicity increase. The addition of NAg to primers seems promising for the improvement of conventional dental adhesives efficacy.
The addition of low concentrations of NAg (250 ppm) to primers were effective to improve antibacterial effect preserving the bond strength and the biocompatibility of the commercial product. NAg/primer association could protect the tooth-adhesive interface increasing dental restoration longevity.
评估含有低浓度银纳米粒子（NAg）的胶粘剂的抗菌效果、细胞毒性和微拉伸结合强度。
将不同浓度的 NAg（50、100、150、200 和 250ppm）掺入 Scotchbond Multi-Purpose 胶粘剂系统（SBMP）的底漆中。使用肉汤微量稀释法测定最小抑菌浓度（MIC）和最小杀菌浓度（MBC）来检测抗菌活性，琼脂扩散法和 MTT 法检测生物膜代谢活性（mutans）。在 24 小时后进行微拉伸结合强度测试（μTBS），然后在蒸馏水中储存 6 个月。将 Nag 条件培养基在 0、24、48 和 72 小时暴露于人牙髓干细胞后，通过 MTT 还原试验评估细胞毒性。结果进行统计学分析（α≤0.05）。
在 25-50ppm 之间发现 MIC，MBC 在 50ppm 的 NAg 下确定。与对照组相比，在琼脂扩散试验中，所有 NAg 组的细菌活性抑制均高于对照组。与对照组相比，250ppm NAg 对生物膜的抑制作用更高。在每个时间段，所有 NAg 组和 SBMP 都表现出相似的细胞毒性。含 200 和 250ppm NAg 的胶粘剂和 SBMP（对照）在 24 小时和 6 个月时均表现出最高的 μTBS 值，与 SBMP 对照相似（p＞0.05）。
含有 250ppm NAg 的商用底漆具有抗菌作用和可靠的结合强度，同时没有增加细胞毒性。在底漆中添加 NAg 似乎有望提高传统牙科胶粘剂的效果。
在底漆中添加低浓度的 NAg（250ppm）可有效提高抗菌效果，同时保持商用产品的结合强度和生物相容性。NAg/底漆的结合可以保护牙-胶界面，增加牙科修复体的使用寿命。
