Enamel around orthodontic brackets coated with flash-free and conventional adhesives.

Abstract

To evaluate enamel roughness and color after debonding flash-free adhesive precoated brackets and brackets coated with conventional orthodontic adhesives using nonbonded enamel as control. Atotal of 80 extracted human premolars were divided into the following four groups: groupI: APCTM Flash-Free adhesive precoated brackets; groupII: APCTM PLUS adhesive precoated brackets; groupIII: noncoated brackets, which were coated manually at the time of bonding (all three brackets were ClarityTM Advanced ceramic brackets [3M Unitek, Monrovia, CA, USA]); groupIV: nonbonded enamel (control). Bonded premolars were subjected to demineralization, and then brackets were debonded. Each group was then divided into two subgroups to assess enamel around the debonded brackets, and also enamel in the control group, using an atomic force microscope and spectrophotometer. In addition, 12samples were used to assess the bracket/adhesive/enamel junction with a scanning electron microscope. Mean values of root mean square roughness (Rq) and maximum profile valley depth (Rv) for APCTM Flash-Free, APCTM PLUS, and ClarityTM Advanced groups were 140 nm and 482 nm, 210 nm and 727 nm, and 447 nm and 1243 nm, respectively. All three groups showed higher roughness and depth values than the control enamel. Spectrophotometer results yielded ∆E* of 3.7 ± 0.6, 5.1 ± 0.4, and 7.1 ± 0.6 for APC™ Flash-Free, APC™ PLUS, and ClarityTM Advanced groups respectively. Color coordinates showed progressively higherL* andb* values and progressively lowera* values from groupI to groupIII. Under the same demineralization conditions, enamel around debonded APC™ Flash-Free adhesive precoated brackets showed less roughness and color changes compared to the other two groups.