Enamel Etching Time for Brackets — NDEB AFK MCQ
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Correct answer: B — 15-30 seconds
The recommended enamel etching time for orthodontic bracket bonding is 15-30 seconds with 37% phosphoric acid. This creates adequate enamel microporosity for resin tag formation without excessive enamel loss. Over-etching (>60 seconds) provides no additional bond strength and removes unnecessary enamel. Under-etching (<10 seconds) provides insufficient microporosity for reliable bonding. After etching, the enamel should appear chalky white (frosty). Contaminated enamel must be re-etched for 10 seconds.
Reference: Proffit – Contemporary Orthodontics, 6th ed., 2019