背景:用37%磷酸调理牙釉质是正畸托槽粘结过程中最常见的技术。然而,由于正畸托槽在治疗过程中反复脱粘,需要其他方法来调理釉质表面并增加粘结强度。本研究旨在比较与单独的酸蚀刻相比,用氧化铝颗粒或5.25%次氯酸钠凝胶喷砂处理搪瓷表面对剪切粘结强度(SBS)的影响。
方法:将拔取的上前磨牙按釉质表面调理法随机分为3组。第一次和第二次金属支架粘接后,新的金属托槽在搪瓷调理后使用不同的方法用全蚀刻粘合剂粘合:仅酸性蚀刻(37%磷酸30秒)(AE组),与酸蚀刻有关的次氯酸钠(5.25%NaOCl凝胶60秒,然后酸蚀刻30秒)(NaOCl-AE组),和与酸蚀刻相关的喷砂(喷砂5秒,然后酸蚀刻30秒)(SB-AE组)。用万能试验机测试托槽的剪切粘结强度。使用单向方差分析(ANOVA)和Tukey的诚实显着差异(HSD)检验来检测第三次粘合时各组之间剪切粘合强度的显着差异。重复测量方差分析和Bonferroni's检验用于检测各组内粘合尝试之间剪切粘合强度的显着差异。
结果:与酸蚀刻方法相关的5.25%次氯酸钠在第三次粘合时产生的剪切粘合强度明显高于与酸蚀刻和仅酸蚀刻方法相关的喷砂(16.40±5.80MPa,13.60.47±6.40MPa,9.90±4.40MPa,分别;P<0.001)。然而,AE组和SB-AE组之间差异无统计学意义(P=0.247)。此外,我们发现,在每次粘合尝试后,每组的剪切粘合强度显着降低。
结论:用5.25%的次氯酸钠与酸蚀相关的处理牙釉质表面产生的结合强度大于仅在第三次结合时通过喷砂与酸蚀相关的处理。金属支架的粘结强度随着粘结尝试的增加而降低,甚至采用搪瓷表面调理的方法。
BACKGROUND: Enamel conditioning with 37% phosphoric acid is the most common technique during orthodontic bracket bonding procedures. However, due to the repeated de-bonding of the orthodontic brackets during treatment, other methods were needed to condition the enamel surface and increase the bond strength. This study aimed to compare the effect of conditioning the enamel surface by sandblasting with aluminum oxide particles or 5.25% sodium hypochlorite gel in combination with acid etching compared to acid etching alone on shear bond strength (SBS).
METHODS: One hundred eight extracted upper premolars were randomly divided into three groups according to the conditioning enamel surface method. After the first and second bonding of metal brackets, new metal brackets were bonded with a total-etching adhesive after enamel conditioning using different methods: acid etching only (37% phosphoric acid for 30 seconds) (AE group), sodium hypochlorite associated with acid etching (5.25% NaOCl gel for 60 seconds and then acid etching for 30 seconds) (NaOCl-AE group), and sandblasting associated with acid etching (sandblasting for five seconds and then acid etching for 30 seconds) (SB-AE group). The shear bond strengths of the brackets were tested with a universal testing machine. One-way analysis of variance (ANOVA) and Tukey\'s honestly significant difference (HSD) tests were used to detect significant differences in shear bond strength among groups at the third bonding. Repeated-measure ANOVA and Bonferroni\'s tests were used to detect significant differences in shear bond strength among the bonding attempts within each group.
RESULTS: 5.25% sodium hypochlorite associated with the acid etching method produced significantly greater shear bond strength than sandblasting associated with acid etching and acid etching only methods at the third bonding (16.40 ± 5.80 MPa, 13.60.47 ± 6.40 MPa, and 9.90 ± 4.40 MPa, respectively; P < 0.001). However, there was no significant difference between the AE and SB-AE groups (P = 0.247). In addition, we found a significant decrease in the shear bond strength within each group after each bonding attempt.
CONCLUSIONS: Conditioning the enamel surface with 5.25% sodium hypochlorite associated with acid etching produced greater bond strength than conditioning by sandblasting associated with acid etching and acid etching only at the third bonding. The bond strength of the metal bracket decreased with increasing bonding attempts, even with the application of enamel surface conditioning methods.