Acessibilidade / Reportar erro

Laboratorial study of loops closure time and degree of cuspid´s tipping, during the retraction phase, using segmented arch mechanics

OBJETIVE: Evaluate the cuspid's retraction time and tipping effects, after submitting it to three different orthodontic retraction loops: the "T" loop, the "boot" loop, and the "tear drop" loop. METHODS: It was used the following orthodontic wires: Morelli 0.019" x 0.025" stainless steel, 3M Unitek 0.019" x 0.025" stainless steel and Ormco 0.019" x 0.025" beta-titanium (TMA™). The resulting sample from the combination of these variables was submitted to a test developed on a typodont simulator used specifically for this purpose. RESULTS: As the closure timing concerns, it was verified that a slower closure and therefore, a smaller releasing force system was achieved by the "T" loop design and still, by employing the beta-titanium alloy on its construction. As to the tipping effects generated by the retraction device, the "tear drop" loop caused greater tipping effects than the other loops evaluated. The "T" loop, on the other hand, showed itself statistically related to the lowest tipping numerical values. However, when the 3M Unitek stainless steel wire was used to produce the device, all of the types of loops evaluated were considered statistically similar. CONCLUSION: Regardless of the loop design, the ones built out of beta-titanium alloy kept them statistically related to the lowest tipping numerical values observed for the retracted dental element.

Orthodontics; Segmented arch; Orthodontic space closure


Dental Press International Av. Luís Teixeira Mendes, 2712 , 87015-001 - Maringá - PR, Tel: (55 44) 3033-9818 - Maringá - PR - Brazil
E-mail: artigos@dentalpress.com.br