Bonding in Orthodontics

Bonding was introduced to orthodontics in 1968 by Newman et al. following acid etching of enamel and the initiation of dental bonding. Ceramic brackets, composed of either monocrystalline or polycrystalline aluminium oxide, are bonded chemically by a silane-coupling agent or mechanically by undercuts and grooves in the base. The increase in adult orthodontics worldwide has brought a concomitant need for the ability to bond metal attachments reliably to artificial substrates such as large composite restorations, amalgam, gold and porcelain. The occlusion must be checked prior to bonding the lower arch to avoid the risk of debonding. Advantages of indirect over direct bonding include improved bracket height positioning and savings in time. Grinding adhesive at debond may speed the production of bisphenol A. A fixed retainer may be bonded directly or indirectly with no significant difference in failure at six months or in risk of failure over 24 months between either technique.