ORIGINAL ARTICLE https://doi.org/10.1007/s00056-020-00241-7 J Orofac Orthop Enamel around orthodontic brackets coated with flash-free and conventional adhesives Mohamed Tarek ElSherifa 1 · Marwa Sameh Shamaa 1 · Mona A. Montasser 1 Received: 19 August 2019 / Accepted: 12 May 2020 © Springer Medizin Verlag GmbH, ein Teil von Springer Nature 2020 Abstract Objective 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. Materials and methods A total of 80 extracted human premolars were divided into the following four groups: group I: APC TM Flash-Free adhesive precoated brackets; group II: APC TM PLUS adhesive precoated brackets; group III: noncoated brackets, which were coated manually at the time of bonding (all three brackets were Clarity TM Advanced ceramic brackets [3M Unitek, Monrovia, CA, USA]); group IV: nonbonded enamel (control). Bonded premolars were subjected to dem- ineralization, 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, 12 samples were used to assess the bracket/adhesive/enamel junction with a scanning electron microscope. Results Mean values of root mean square roughness (Rq) and maximum profile valley depth (Rv) for APC TM Flash-Free, APC TM PLUS, and Clarity TM 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 Clarity TM Advanced groups respectively. Color coordinates showed progressively higher L* and b* values and progressively lower a* values from group I to group III. Conclusions 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. Keywords White spots · Tooth demineralization · Orthodontic treatment · Spectrophotometer · Scanning electron microscope Zahnschmelz im Bereich von mit flash free und konventionellen Adhäsiven beschichteten kieferorthopädischen Brackets Zusammenfassung Zielsetzung Beurteilung von Schmelzrauigkeit und -farbe von mit Flash-Free-Adhäsiv vorbeschichteten Brackets und von mit konventionellen kieferorthopädischen Adhäsiven beschichteten Brackets nach dem Debonding, wobei nichtbeschich- teter Zahnschmelz als Kontrolle herangezogen wurde.  Dr. Mona A. Montasser mmontasser11@yahoo.com 1 Orthodontic Department, Faculty of Dentistry, Mansoura University, 35516 Mansoura, Egypt K