Department of Orthodontics, College of Dentistry, University of Baghdad, Baghdad, Iraq.
Department of Oral Biology, Dow Dental College, Dow University of Health Sciences, Karachi, Pakistan.
Clin Exp Dent Res. 2024 Dec;10(6):e948. doi: 10.1002/cre2.948.
This study investigated the effects of adding tricalcium silicate nanoparticles (TCSNp) to the universal G2 bond adhesive (G2BU) in self-etch (SE) mode on shear bond strength (SBS) to orthodontic brackets, cytotoxicity, and degree of conversion (DC).
A total of 176 human teeth were divided into four groups based on TCSNp concentration in G2BU adhesive: 0% (control), 1%, 3%, and 5%. The G2BU adhesive consists of a hydrophilic primer (P) and a hydrophobic bonding agent (2B). TCSNp were added to the 2B component by mixing 0.1, 0.3, and 0.5 g of TCSNp with 9.9, 9.7, and 9.5 g of 2B, respectively. SBS was assessed after 24 h of water storage and 5000 thermocycles using a universal testing machine. Cytotoxicity was evaluated using the MTT assay on rat embryo fibroblast cells, and DC was measured using fourier-transform infrared spectroscopy. Statistical analysis included one-way ANOVA and Tukey's post-hoc test, with significance set at p < 0.05.
After 24 h, mean SBS values were 15.58 MPa (control), 13.66 MPa (1% TCSNp), 15.99 MPa (3% TCSNp), and 12.04 MPa (5% TCSNp). After 5000 thermocycles, SBS values decreased to 12.91 MPa (control), 12.42 MPa (1% TCSNp), 11.11 MPa (3% TCSNp), and 10.21 MPa (5% TCSNp). ANOVA showed significant differences between groups (p < 0.05), except between the control and 3% TCSNp groups. Cell viability increased with higher TCSNp concentrations, with significant differences at 72 h between control and 5% TCSNp groups (p = 0.014). Mean DC values were 51.66% (control), 49.33% (1% TCSNp), 49.66% (3% TCSNp), and 48% (5% TCSNp). ANOVA indicated no significant differences between groups.
Adding TCSNp to G2BU in SE mode maintains clinically acceptable SBS levels and enhances cytocompatibility. Higher TCSNp concentrations may reduce SBS and DC slightly. Further studies are needed to evaluate long-term effects.
本研究旨在探讨在自酸蚀（SE）模式下将硅酸三钙纳米粒子（TCSNp）添加到通用 G2 粘结剂（G2BU）中对正畸托槽的剪切粘结强度（SBS）、细胞毒性和转化率（DC）的影响。
将 176 个人类牙齿根据 G2BU 粘结剂中 TCSNp 的浓度分为四组：0%（对照组）、1%、3%和 5%。G2BU 粘结剂由亲水底漆（P）和疏水性粘结剂（2B）组成。TCSNp 分别通过将 0.1、0.3 和 0.5g 的 TCSNp 与 9.9、9.7 和 9.5g 的 2B 混合添加到 2B 成分中。使用万能试验机在水储存 24 小时和 5000 次热循环后评估 SBS。使用大鼠胚胎成纤维细胞通过 MTT 测定法评估细胞毒性，使用傅里叶变换红外光谱法测量 DC。统计分析包括单因素方差分析和 Tukey 事后检验，显著性水平设为 p<0.05。
24 小时后，平均 SBS 值分别为 15.58 MPa（对照组）、13.66 MPa（1% TCSNp）、15.99 MPa（3% TCSNp）和 12.04 MPa（5% TCSNp）。经过 5000 次热循环后，SBS 值降至 12.91 MPa（对照组）、12.42 MPa（1% TCSNp）、11.11 MPa（3% TCSNp）和 10.21 MPa（5% TCSNp）。方差分析显示各组之间存在显著差异（p<0.05），除对照组和 3% TCSNp 组之间外。细胞活力随 TCSNp 浓度的增加而增加，对照组和 5% TCSNp 组在 72 小时时差异有统计学意义（p=0.014）。平均 DC 值分别为 51.66%（对照组）、49.33%（1% TCSNp）、49.66%（3% TCSNp）和 48%（5% TCSNp）。方差分析显示组间无显著差异。
在 SE 模式下将 TCSNp 添加到 G2BU 中可保持临床可接受的 SBS 水平并提高细胞相容性。较高的 TCSNp 浓度可能会略微降低 SBS 和 DC。需要进一步研究以评估长期影响。
