AIM: The objective of this in vitro study was to evaluate the bond strength and the debonding pattern of different bracket bonding systems (Transbond XT System / 3M-Unitek and Enlight System / Ormco) whose respective adhesives were pre-mixed with chlorhexidine varnish (Cervitec / Ivoclar-Vivadent). METHODS: The sample used consisted of sixty human pre-molars extracted for orthodontic purposes, included in PVC cylinder and randomly divided in four experimental groups: group 1 - Transbond XT System according to the manufacturer’s instructions; group 2 - Transbond XT System combined with chlorhexidine varnish; group 3 - Enlight System according to the manufacturer’s instructions; group 4 - Enlight System combined with chlorhexidine varnish. The bond strength evaluation was obtained through the shear bond strength test by EMIC universal test machine (0.5mm/minute); the debonding pattern evaluation was obtained by STEMI 2000-C/Zeiss (20x) stereoscopic microscope through observation of the adhesive remnant index (ARI) on the tooth’s enamel surface after bracket debonding. RESULTS: Between the experimental groups (groups 2 and 4) and the respective control groups (groups 1 and 3) there was no significant statistical difference (p < 0.05). CONCLUSIONS: The bond strength and the debonding pattern were not altered for association of the chlorhexidine varnish with respective adhesives of the tested bonding systems.
Orthodontic brackets; Shear bond strength; Chlorhexidine
