Related Experiment Video
Updated: Jul 15, 2026
Development of Amelogenin-chitosan Hydrogel for In Vitro Enamel Regrowth with a Dense Interface
Published on: July 10, 2014
Examination of enamel-adhesive interface with focused ion beam and scanning electron microscopy
Rogelio José Scougall Vilchis1, Yasuaki Hotta, Kohji Yamamoto
1Department of Operative Dentistry, Division of Oral Functional Sciences and Rehabilitation, School of Dentistry, Asahi University, Mizuho City, Gifu Pref, Japan. rogelio@dent.asahi-u.ac.jp
Introduction:
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.
Methods:
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.
Results:
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.
Conclusions:
Focused ion-beam milling to prepare samples allowed clear observation of the enamel-adhesive interface without artificial damage.
