背景:白点的形成,代表早期龋齿病变,是固定正畸的一个主要问题。向正畸粘合剂中添加再矿化剂可以防止白点的形成。这项研究的目的是生产一种复合正畸粘合剂结合纳米生物活性玻璃-银(nBG@Ag)用于支架粘结牙釉质,并研究其细胞毒性,抗菌活性,再矿化能力,和粘结强度。
方法:使用溶胶-凝胶法合成nBG@Ag,并使用透射电子显微镜(TEM)进行表征,X射线衍射(XRD)和傅里叶变换红外光谱与衰减全反射附件(ATR-FTIR)。含1%胶粘剂的细胞毒性试验(MTT)和抗菌活性,3%,和5%(wt/wt)nBG@Ag进行评估,使用万能试验机测量粘合剂的剪切粘合强度。通过使用维氏显微硬度计和扫描电子显微镜(SEM)的显微硬度测试来评估再矿化。使用Shapiro-Wilk检验进行统计分析,平衡试验,单向方差分析,Robust-Welch试验,TukeyHSD方法,和双向方差分析。
结果:发现粘合剂的生物相容性很高,如样品组和对照组之间的细胞毒性没有显着差异所证实的。由含有nBG@Ag的复合材料制成的圆盘显示变形链球菌的生长显着降低(p<0.05),抗菌活性随着nBG@Ag百分比的增加而增加。添加纳米粒子后,粘合剂的剪切粘合强度显着下降(p<0.001),但仍高于建议值。nBG@Ag的添加显示出牙齿显微硬度的改善,尽管研究组之间的显微硬度差异无统计学意义.通过SEM和能量色散X射线光谱(EDX)确认了牙齿表面上羟基磷灰石沉积物的形成。
结论:在正畸粘合剂中添加nBG@Ag可以是增强抗菌活性和减少正畸托槽周围牙釉质脱矿的有效方法,不损害生物相容性和粘结强度。
BACKGROUND: The formation of white spots, which represent early carious lesions, is a major issue with fixed orthodontics. The addition of remineralizing agents to orthodontic adhesives may prevent the formation of white spots. The aim of this study was to produce a composite orthodontic adhesive combined with nano-bioactive glass-silver (nBG@Ag) for bracket bonding to enamel and to investigate its cytotoxicity, antimicrobial activity, remineralization capability, and bond strength.
METHODS: nBG@Ag was synthesized using the sol-gel method, and characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy with an attenuated total reflectance attachment (ATR-FTIR). The cytotoxicity test (MTT) and antimicrobial activity of adhesives containing 1%, 3%, and 5% (wt/wt) nBG@Ag were evaluated, and the shear bond strength of the adhesives was measured using a universal testing machine. Remineralization was assessed through microhardness testing with a Vickers microhardness tester and scanning electron microscopy (SEM). Statistical analyses were conducted using the Shapiro-Wilk test, Levene test, one-way ANOVA, Robust-Welch test, Tukey HSD method, and two-way ANOVA.
RESULTS: The biocompatibility of the adhesives was found to be high, as confirmed by the lack of significant differences in the cytotoxicity between the sample and control groups. Discs made from composites containing nBG@Ag exhibited a significant reduction in the growth of Streptococcus mutans (p < 0.05), and the antibacterial activity increased with higher percentages of nBG@Ag. The shear bond strength of the adhesives decreased significantly (p < 0.001) after the addition of nanoparticles, but it remained above the recommended value. The addition of nBG@Ag showed improvement in the microhardness of the teeth, although the differences in microhardness between the study groups were not statistically significant. The formation of hydroxyapatite deposits on the tooth surface was confirmed through SEM and energy-dispersive X-ray spectroscopy (EDX).
CONCLUSIONS: Adding nBG@Ag to orthodontic adhesives can be an effective approach to enhance antimicrobial activity and reduce enamel demineralization around the orthodontic brackets, without compromising biocompatibility and bond strength.