Analise in vitro da resistencia ao cisalhamento de braquetes metalicos colados em varias condições de esmalte

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

The purpose of this study was to compare the shear bond strength of metallic brackets with the composite Transbond XT (3M Unitek, Monrovia, USA) in several enamel preparations and to evaluate, after the debonded process, the adhesive remnant index (ARI). One hundred and fourteen bovine permanent inferior incisors were included in plastic tubes, in a center position, with an acrylic resin leaving the vestibular face of the tooth perpendicular to the bottom plane of the tube. The vestibular face of all the teeth were cleared with a nonfluoridated pumice and water for 10 seconds, washed, dried for the same time and divided in eight groups: Group I- the composite Transbond XT was used in a conventional way; Group IIthe enamel was dried and the Transbond MIP (3M Unitek, Monrovia, USA) was applied; Group III- the enamel was contaminated with human saliva and the Transbond MIP was applied; Group IV- the enamel was moistened with distilled water and soon afterwards the Transbond MIP was applied; Group V- enamel was etched with 37% phosphoric acid for 30 seconds, washed, dried and applied the same primer of the Groups II, III and IV; Groups VI, VII and VIII- Transbond Plus Self Etching Primer (3M Unitek, Monrovia, USA) was applied in dry enamel, contaminated with saliva and moistened with distilled water, respectively. In all groups the brackets were bonded with the composite Transbond XT. Twenty four hours after the bonded the brackets were submitted to shear bond strength in Instron machine in a 0,5 mm / minute crosshead speed. The medium values of shear bond strength found were 6.12 MPa for the Group I, 1.94 MPa for the Group II, 1.46 MPa for the Group III, 1.99 MPa for the Group IV, 8.14 MPa for the Group V, 10.01 MPa for the Group VI, 7.75 MPa for the Group VII and 8.91 MPa for the Group VIII. Among the groups I, V, VI, VII and VIII, there were not found significant statistical differences in the medium values of shear bond strength. However were statistically higher than groups II, III e IV, which were not different statistically among then. The same statistical differences were observed in relation to the values of the adhesive remnant index (ARI).

ASSUNTO(S)

resinas compostas ortodontia

ACESSO AO ARTIGO

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