Surface roughness and surface free energy components of various orthodontic adhesives

Ahn, Hyo Beom; Ahn, Sug Joon; Nahm, Dong Seok

Abstract

OBJECTIVE
Surface characteristics of dental materials play an important role in bacterial adhesion. The purpose of this study was to investigate surface characteristics of 5 different light-cured orthodontic adhesives (1 fluoride-releasing composite, 3 non-fluoride-releasing composites, and 1 resin-modified glass ionomer).
METHODS
Surface roughness was measured using a confocal laser scanning microscope. Contact angle and surface free energy components were analyzed using the sessile drop method.
RESULTS
Surface roughness was significantly different between adhesives despite a relatively small variation (less than 0.05 micrometer). Lightbond and Monolok2 were rougher than Enlight and Transbond XT. There were also significant differences in contact angles and surface free energy components between adhesives. In particular, considerable differences in contact angles and surface free energy components were found between resin modified glass ionomer and the composites. Resin modified glass ionomer showed significantly smaller contact angles in 3 different probe liquids and had higher total surface free energy and stronger polarity, with notably stronger basic property than the composites.
CONCLUSION
Resin modified glass ionomer may provide a more favourable environment for bacterial adhesion than composite adhesives.