Biria Mina, Namaei Ghasemi Sajedeh, Sheikh-Al-Eslamian Seyedeh Mahsa, Panahandeh Narges
Department of Pediatric Dentistry, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Private Practice, Tehran, Iran.
J Dent Res Dent Clin Dent Prospects. 2019 Fall;13(4):305-310. doi: 10.15171/joddd.2019.046.
This in vitro study aimed to evaluate the microshear bond strength (μSBS), microhardness and morphological characteristics of primary enamel after treating with sodium fluoride (NaF) and acidulated phosphate fluoride (APF). Forty-eight primary canines were cut into mesial and distal sections and assigned to five groups randomly: group 1 (immersed in saliva as a control), group 2 (treated with NAF and immersed in saliva for 30 minutes), group 3 (treated with APF and immersed in saliva for 30 minutes), group 4 (treated with NAF and immersed in saliva for 10 days), and group 5 (treated with APF and immersed in saliva for 10 days). Composite resin (Filtek Z250) was bonded on the specimens (n=15) for measuring the μSBS. After storage in 37°C artificial saliva for 24 hours, µSBS and Vickers hardness tests (10 readings) were performed. The data were analyzed using one-way ANOVA and Kolmogorov-Smirnov, Levene's and Tukey HSD tests (P<0.05). Morphological analysis of enamel and modes of failure were carried out under a scanning electron microscope (SEM) on two remaining specimens. Significant differences in μSBS were only noted between groups 2 and 4 (P=0.024). Group 3 showed a significant decrease in hardness after storage in artificial saliva (P<0.001), with a significantly lower hardness than the other groups (P<0.001). The SEM observations showed irregular particles in groups 3 and 5; uniform, smooth and thin coats were seen in groups 2 and 4. Fluoride therapy with NaF and APF gels prior to restorative treatments had no adverse effects on the microshear bond strength.
本体外研究旨在评估用氟化钠（NaF）和酸性磷酸氟（APF）处理后乳牙釉质的微剪切粘结强度（μSBS）、显微硬度和形态特征。将48颗乳尖牙切成近中面和远中面，随机分为五组：第1组（浸泡在唾液中作为对照），第2组（用NaF处理并在唾液中浸泡30分钟），第3组（用APF处理并在唾液中浸泡30分钟），第4组（用NaF处理并在唾液中浸泡10天），第5组（用APF处理并在唾液中浸泡10天）。将复合树脂（Filtek Z250）粘结在标本（n = 15）上以测量μSBS。在37°C人工唾液中储存24小时后，进行μSBS和维氏硬度测试（10次读数）。使用单因素方差分析以及Kolmogorov-Smirnov、Levene's和Tukey HSD检验（P<0.05）对数据进行分析。在扫描电子显微镜（SEM）下对另外两个标本进行釉质的形态分析和断裂模式分析。仅在第2组和第4组之间观察到μSBS有显著差异（P = 0.024）。第3组在人工唾液中储存后硬度显著降低（P<0.001），其硬度显著低于其他组（P<0.001）。SEM观察显示第3组和第5组中有不规则颗粒；第2组和第4组中可见均匀、光滑且薄的涂层。在修复治疗前用NaF和APF凝胶进行氟化物治疗对微剪切粘结强度没有不良影响。
