Zaher Abbas R, Abdalla Essam M, Abdel Motie Maha A, Rehman Noman Atiq, Kassem Hassan, Athanasiou Athanasios E
Alexandria University, Alexandria, Egypt.
J Orthod. 2012 Jun;39(2):82-8. doi: 10.1179/1465312512Z.0000000009.
To test the possible association between enamel colour alteration and resin tag depth.
In vitro laboratory study.
Department of Orthodontics, Alexandria University, Egypt.
Fifty freshly extracted human premolar teeth were equally divided randomly into a control and four experimental groups. Teeth in group I received only enamel prophylaxis. Teeth in groups II and III were etched with 35% phosphoric acid for 15 and 60 seconds, respectively. Teeth in group IV were conditioned with Prompt L-pop self-etching primer and in group V with Xeno III self-etching primer, according to the manufacturer's instructions. Orthodontic brackets were bonded to the teeth in all experimental groups using Transbond XT composite. Following bracket debonding, finishing and polishing were performed. Enamel colour was evaluated spectrophotometrically at baseline and then after debonding, with the corresponding colour differences ΔE calculated. Resin tags lengths were measured on sectioned teeth in each experimental group under scanning electron microscope.
All experimental groups showed clinically perceivable colour change after debonding and finishing as all values were exceeded the clinical colour detection threshold of ΔE = 3.7 units. Significant differences (P<0.05) in resin tag length were found in all experimental groups. Significant moderate correlation was found between colour change and resin tags length when all teeth were combined and tested, irrespective of group.
Moderate evidence exists that shorter resin tag penetration produces less change in enamel colour following clean-up and polishing. Self-etch primers produce less resin penetration and these systems may produce less iatrogenic colour change in enamel following orthodontic treatment.
测试牙釉质颜色改变与树脂突深度之间可能存在的关联。
体外实验室研究。
埃及亚历山大大学正畸科。
将50颗新鲜拔除的人类前磨牙随机均分为一个对照组和四个实验组。第一组的牙齿仅进行牙釉质清洁。第二组和第三组的牙齿分别用35%磷酸酸蚀15秒和60秒。第四组的牙齿按照制造商的说明用Prompt L-pop自酸蚀底漆处理，第五组用Xeno III自酸蚀底漆处理。所有实验组的牙齿均使用Transbond XT复合材料粘结正畸托槽。托槽拆除后，进行修整和抛光。在基线时以及拆除托槽后用分光光度法评估牙釉质颜色，并计算相应的颜色差异ΔE。在扫描电子显微镜下测量每个实验组切片牙齿上的树脂突长度。
所有实验组在拆除托槽和修整后均出现临床上可察觉的颜色变化，因为所有数值均超过了临床颜色检测阈值ΔE = 3.7单位。所有实验组在树脂突长度上均存在显著差异（P<0.05）。当将所有牙齿合并测试时，无论组别如何，在颜色变化与树脂突长度之间均发现显著的中度相关性。
有中等证据表明，较短的树脂突侵入在清理和抛光后对牙釉质颜色的改变较小。自酸蚀底漆导致的树脂侵入较少，并且这些系统在正畸治疗后可能在牙釉质中产生较少医源性颜色改变。
