Enamel conditioning for orthodontic bonding with a single-step bonding agent.

Abstract

In-vitro evaluation of an alternative method to the conventional acid etch technique. 240 human anterior and posterior teeth were divided into 16 groups of 15 teeth each. Group variables were: tooth type, enamel conditioning technique (Prompt L-Pop((R)): 3M Espe, Seefeld, Germany, or 37% phosphoric acid and bonding), adhesive (Transbond trade mark XT: 3M Unitek, Monrovia, CA, USA and ENlight((R)): Ormco, Orange, CA, USA), and testing procedure (shear and tensile bond strength). Upper lateral incisors and premolar brackets (Mini-Diamond((R)): Ormco, Orange, CA, USA) were used. Intergroup differences were analyzed by an analysis of variance. The enamel surface and the failure mode of debonded specimens were investigated with light and scanning electron microscopy. Despite a tendency towards a higher bond strength after phosphoric acid conditioning, no statistically significant differences were found between the enamel conditioning methods. Statistically significant differences were recorded for the different adhesives: bond strength with Transbond trade mark XT was higher than with Enlight((R)). The single-step bonding agent sems to provide an acceptable bond strength between adhesive and enamel. No enamel fractures were detected. In vivo studies will be conducted to investigate the clinical performance of the new material.