Department of Prosthodontics, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China.
Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University Zurich, Zurich, Switzerland.
BMC Oral Health. 2019 Mar 27;19(1):50. doi: 10.1186/s12903-019-0742-4.
A reduction in bond strength of bleached enamel has been confirmed in the literature. Although limited information is available, it is conceivable that the veneer preparation process may remove the impacted enamel and further eliminate the compromised bond strength between the composite resin and bleached enamel. This study aimed to evaluate the effect of surface removal following bleaching on the micro-shear bond strength (μSBS) of bleached enamel.
Forty-eight specimens were prepared from bovine incisors and were randomly divided into 2 groups (n = 24): group B (bleaching with 40% hydrogen peroxide for 2 × 45 min with a 1-week interval) and group C (control group without bleaching treatment). Immediately after receiving the treatments, 0.5 mm of the enamel was removed from the specimen surface, followed by bonding of composite resin to the enamel surface. Each group was further divided into 2 subgroups of 12 specimens each: subgroup T (with 5000 thermocycles in water baths at 5 °C and 55 °C), and subgroup N (without thermocycling). The μSBS values were measured using a universal testing machine and subjected to two-way analysis of variance (α = 0.05). The fracture modes of the specimens were observed using a stereomicroscope.
The μSBS values of the different groups ranged from 21.42 to 25.21 MPa. Following a surface reduction of 0.5 mm, bleaching treatment and thermocycling did not significantly affect the μSBS values (P = 0.348 and P = 0.507, respectively). No significant interaction was found between the bleaching treatment and thermocycling (P = 0.514). All the groups exhibited a high percentage of mixed failures. Compared with group C, group B exhibited higher percentage of adhesive failure.
The results suggested that the bonding procedure could be performed on the bleached enamel following a surface reduction of 0.5 mm immediately after the bleaching treatment.
文献已经证实，漂白后的牙釉质粘结强度会降低。虽然可用的信息有限，但可以想象，贴面预备过程可能会去除受影响的牙釉质，并进一步消除复合树脂与漂白牙釉质之间受损的粘结强度。本研究旨在评估漂白后表面去除对漂白牙釉质微剪切粘结强度（μSBS）的影响。
从牛切牙制备 48 个样本，并随机分为 2 组（n=24）：组 B（用 40%过氧化氢漂白，每 45 分钟 2 次，间隔 1 周）和组 C（无漂白处理的对照组）。治疗后立即从样本表面去除 0.5mm 的牙釉质，然后将复合树脂粘结到牙釉质表面。每组进一步分为 2 个亚组（每组 12 个样本）：亚组 T（在 5°C 和 55°C 的水浴中进行 5000 次热循环）和亚组 N（不进行热循环）。使用万能试验机测量 μSBS 值，并进行双因素方差分析（α=0.05）。使用立体显微镜观察样本的断裂模式。
不同组的 μSBS 值范围为 21.42 至 25.21 MPa。表面减少 0.5mm 后，漂白处理和热循环对 μSBS 值没有显著影响（P=0.348 和 P=0.507）。漂白处理和热循环之间没有发现显著的相互作用（P=0.514）。所有组均显示出较高比例的混合失效。与组 C 相比，组 B 显示出更高比例的粘固失败。
结果表明，在漂白处理后立即进行 0.5mm 的表面减少处理，可以在漂白牙釉质上进行粘结程序。
