BACKGROUND: The aim of this in vitro study was to determine the effect of four different orthodontic adhesive removal techniques on sound, demineralized and remineralized enamel. METHODS: Composite resin adhesive was bonded to 100 teeth which were divided into four groups with each comprising five sound teeth and 20 teeth with demineralized and remineralized lesions adjacent to the adhesive. Adhesive was removed with either: (1) slow speed bur (SS); (2) high speed bur (HS); (3) aluminium oxide disc (DC); or (4) ultrasonic scaler (US). Damage to the enamel was assessed using white light profilometry, digital photography and scanning electron microscopy. RESULTS: The least to greatest mean depth of damage with the four different adhesive removal techniques to sound enamel was DC = SS < US = HS and to demineralized and remineralized enamel were DC < HS < US = SS. Sound enamel experienced the least amount of damage. Remineralization prior to adhesive removal significantly reduced the amount of damage produced by all techniques compared with demineralized enamel. Discs were the least damaging to demineralized and remineralized enamel compared with the other removal techniques. CONCLUSIONS: When demineralization was present discs were found to be the least damaging adhesive removal technique and remineralization further reduced the amount of enamel damage.