Vilchis Rogelio José Scougall, Hotta Yasuaki, Yamamoto Kohji
Department of Operative Dentistry, Division of Oral Functional Sciences and Rehabilitation, School of Dentistry, Asahi University, Mizuho City, Gifu Pref, Japan.
Am J Orthod Dentofacial Orthop. 2007 May;131(5):646-50. doi: 10.1016/j.ajodo.2006.11.017.
The purpose of this study was to observe, with a scanning electron microscope, the interface between enamel and orthodontic adhesive after focused ion-beam milling. In addition, enamel etched with phosphoric acid was compared with enamel conditioned with self-etching primer.
Four freshly extracted human premolars were collected and pumiced by using rubber cups with fluoride-free paste, washed, and dried. The enamel of 2 teeth was etched with 37% phosphoric acid for 30 seconds, washed, and dried; the enamel of the other 2 teeth was conditioned with self-etching primer for 5 seconds. Stainless steel brackets were bonded with Transbond XT adhesive (3M Unitek, Monrovia, Calif) according to the manufacturer's instructions. The specimens were milled by focused ion beam and observed under the scanning electron microscope.
The scanning electron micrographs showed that 37% phosphoric acid seemed to produce more enamel loss than the self-etching primer. Moreover, the enamel-adhesive interface was more irregular when the enamel was etched with 37% phosphoric acid. Finally, a gentler etch pattern of the self-etching primer on the enamel surface was observed, and this conditioner could be used clinically for minimal intervention in the orthodontic bonding procedure.
Focused ion-beam milling to prepare samples allowed clear observation of the enamel-adhesive interface without artificial damage.
本研究的目的是通过扫描电子显微镜观察聚焦离子束铣削后牙釉质与正畸粘合剂之间的界面。此外，还将用磷酸蚀刻的牙釉质与用自酸蚀底漆处理的牙釉质进行了比较。
收集四颗新鲜拔除的人类前磨牙，用不含氟化物的糊剂的橡胶杯进行打磨、冲洗和干燥。两颗牙齿的牙釉质用37%的磷酸蚀刻30秒，冲洗并干燥；另外两颗牙齿的牙釉质用自酸蚀底漆处理5秒。按照制造商的说明，用Transbond XT粘合剂（3M Unitek，蒙罗维亚，加利福尼亚州）粘结不锈钢托槽。通过聚焦离子束对标本进行铣削，并在扫描电子显微镜下观察。
扫描电子显微镜照片显示，37%的磷酸似乎比自酸蚀底漆造成更多的牙釉质损失。此外，当用37%的磷酸蚀刻牙釉质时，牙釉质-粘合剂界面更不规则。最后，观察到自酸蚀底漆在牙釉质表面的蚀刻图案更平缓，这种处理剂可在临床上用于正畸粘结过程中的微创干预。
通过聚焦离子束铣削制备样品可以在无人工损伤的情况下清晰观察牙釉质-粘合剂界面。
