次氯酸钠暴露时间对氟斑牙酸蚀前微剪切粘结强度的影响。

Effect of Exposure Times of Sodium Hypochlorite before Acid Etching on the Microshear Bond Strength to Fluorotic Enamel.

出版信息

J Clin Pediatr Dent. 2021 Nov 1;45(5):317-322. doi: 10.17796/1053-4625-45.5.5.

DOI:10.17796/1053-4625-45.5.5

Abstract

PURPOSE

To evaluate the effects of different treatment time of 5.25% Sodium hypochlorite (NaOCl) on the microshear bond strength (μSBS), attenuated total reflection Fourier transform infrared (ATR-FTIR) and etching pattern in mild and moderate fluorotic enamel.

STUDY DESIGN

Forty-eight fluorotic molars were divided into two groups: mild and moderate fluorotic enamel which were classified by a Thylstrup and Fejerskov index (TFI). Based on the application time (0s, 60s, 120s, 180s) of 5.25% NaOCl, each group was sectioned into four parts. Then the etched enamel was bonded with resin and tested to acquire μSBS. The statistical method was two-way ANOVA and Least Significant Difference (LSD) test at α = 0.05. Besides, fracture modes were observed under a stereo microscope. SEM was used to evaluated the enamel-etching pattern and organic content on the fluorotic enamel surface were investigated by ATR-FTIR.

RESULTS

Duration of 5.25% NaOCl at 60s or 120s significantly increased the μSBS of fluorotic enamel compared to 0s (p<0.05). Fracture modes indicated that dominating failures were set in the bonding interface but whose proportion decreased when 5.25% NaOCl was applied. The enamel-etching pattern in 180s was deepest under SEM. Spectra of enamel samples manifested an obvious and gradual removal of its organic phase after duration of NaOCl increased.

CONCLUSION

The maximal μSBS is acquired by using 5.25% NaOCl at 60s for mild fluorotic enamel but 120s for the moderate. The prolonged application time of 5.25% NaOCl prior to phosphoric acid etching improves enamel-etching pattern. Treatment of 5.25% NaOCl decreases proteins on the fluorotic enamel surface.

摘要

目的

评估不同次氯酸钠（NaOCl）处理时间对轻度和中度氟斑牙釉质微拉伸粘结强度（μSBS）、衰减全反射傅里叶变换红外光谱（ATR-FTIR）和蚀刻模式的影响。

研究设计

将 48 颗氟斑磨牙分为轻度氟斑牙釉质和中度氟斑牙釉质两组，根据 5.25% NaOCl 的应用时间（0s、60s、120s、180s），每组分为四部分。然后用树脂粘结处理后的釉质并进行 μSBS 测试。采用双向方差分析和最小显著差异（LSD）检验，α=0.05。此外，用立体显微镜观察断裂模式。用 SEM 评估氟斑牙釉质表面的蚀刻模式，用 ATR-FTIR 研究其有机含量。

结果

与 0s 相比，60s 或 120s 的 5.25% NaOCl 处理时间显著提高了氟斑牙釉质的 μSBS（p<0.05）。断裂模式表明，主要失效模式发生在粘结界面，但当使用 5.25% NaOCl 时，其比例降低。SEM 下，180s 的蚀刻模式最深。随着 NaOCl 处理时间的延长，釉质样本的光谱显示其有机相明显且逐渐去除。