J Adhes Dent. 2023 Oct 16;25:187-194. doi: 10.3290/j.jad.b4515497.
Resin composites are commonly used in pediatric dentistry, but there is limited evidence on adhesion to primary teeth, especially primary enamel. In this study, three bonding strategies were assessed - one-step self-etch (1-SE), two-step self-etch (2-SE), and three-step etch-and-rinse (3-ER) - by measuring the immediate and aged microshear bond strength (µSBS) to sound primary enamel.
120 extracted human primary molars with sound buccal surfaces were used for µSBS testing. Six adhesive protocols (two per bonding strategy) were selected and µSBS was measured either after 24 h or 10,000 thermal cycles (n = 10). Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were used to determine failure modes. Furthermore, 18 primary molars were etched using the different adhesive protocols (n = 3) for the measurement of surface roughness (Sa) using CLSM and morphological analysis using SEM.
After 24 h, there was no significant difference in µSBS between 1-SE and 2-SE strategies (p = 0.96), but the 2-SE strategy yielded significantly higher µSBS after thermocycling (p < 0.001). The highest µSBS was obtained using the 3-ER strategy regardless of aging (p < 0.001). The 3-ER strategy clearly exposed enamel prisms and resulted in the highest Sa (p < 0.001). In contrast, if SE strategies were used, enamel prisms were barely recognizable, and Sa was not significantly different from baseline (p > 0.95).
The 3-ER strategy is optimal for bonding to primary enamel. The etching effect of SE strategies is weaker, resulting in lower µSBS. Thermocycling revealed that the bonding durability of the 1-SE strategy is inferior to that of to multi-step strategies.
树脂复合材料在儿童牙科中广泛应用，但关于其对乳牙，特别是乳牙釉质的黏附力的证据有限。本研究通过测量对健康乳牙釉质即刻和老化微拉伸黏结强度（µSBS），评估了三种黏接策略——一步自酸蚀（1-SE）、两步自酸蚀（2-SE）和三步酸蚀-冲洗（3-ER）。
使用 120 颗具有健康颊面的人离体乳磨牙进行µSBS 测试。选择了六种黏接剂方案（每种黏接策略各两种），分别在 24 h 或 10,000 次热循环后（n = 10）测量µSBS。共聚焦激光扫描显微镜（CLSM）和扫描电子显微镜（SEM）用于确定失效模式。此外，使用不同的黏接剂方案（n = 3）对 18 颗乳磨牙进行酸蚀，通过 CLSM 测量表面粗糙度（Sa），并用 SEM 进行形态分析。
24 h 时，1-SE 和 2-SE 策略之间的µSBS 无显著差异（p = 0.96），但热循环后 2-SE 策略的µSBS 显著更高（p < 0.001）。无论老化情况如何，3-ER 策略均可获得最高的µSBS（p < 0.001）。3-ER 策略可清晰暴露釉柱，且 Sa 最高（p < 0.001）。相比之下，如果使用 SE 策略，釉柱几乎不可见，Sa 与基线无显著差异（p > 0.95）。
3-ER 策略是黏接乳牙釉质的最佳策略。SE 策略的蚀刻效果较弱，导致µSBS 较低。热循环显示，1-SE 策略的黏接耐久性不如多步策略。
