Artun J
Department of Orthodontics, University of Washington, Seattle, USA.
Eur J Orthod. 1997 Apr;19(2):219-28. doi: 10.1093/ejo/19.2.219.
The purpose of this study was to perform a clinical evaluation of ceramic brackets with silane-coated bases for chemical (Transcend) and microcrystalline bases for mechanical (Transcend 2000) retention. The sample consisted of 49 consecutive patients; the first 30 were treated with brackets with chemical retention and the following 19 with brackets with mechanical retention. For each patient the brackets on one side of the mouth were assigned at random to be bonded with Concise and the other with Transbond as recommended by the manufacturers. Levelling and alignment of severely displaced roots was initiated with superelastic wires and completed with stainless steel wires. Any space closure or correction of interarch discrepancy was performed with rectangular stainless steel wires. The brackets with chemical retention were removed with a torsional rotation debonding wrench, and those with mechanical retention with a tensile debonding plier. The bond failure rate was low, with no difference between the two bracket types or between brackets bonded with Concise and Transbond. Bracket fracture was a significant clinical problem, both during active treatment and at the time of appliance removal. New teeth with formation of pronounced enamel cracks were seen in 20.6 and 10.5 per cent of the teeth treated with brackets with chemical and mechanical retention, respectively (P < 0.001), with no difference between teeth bonded with Concise and Transbond. Enamel tear-outs were seen in 3 of the 544 and in 1 of the 344 teeth treated with the respective types of bracket. These teeth were bonded with Concise.
