Clinical evaluation of the failure rate of metallic brackets bonded with orthodontic composites

ABSTRACT

The purpose of the present study was to evaluate in vivo the failure rate of metallic brackets bonded with two orthodontic composites. Nineteen patients with ages ranging from 10.5 to 38.7 years needing corrective orthodontic treatment were selected for study. The enamel surfaces from second premolars to second premolars were treated with Transbond Plus-Self Etching Primer (3M Unitek). Next, 380 orthodontic brackets were bonded on maxillary and mandibular teeth, as follows 190 with Transbond XT composite (3M Unitek) (control) and 190 with Transbond Plus Color Change (3M Unitek) (experimental) in contralateral quadrants. The bonded brackets were light cured for 40 s, and initial alignment archwires were inserted. Bond failure rates were recorded over a six-month period. At the end of the evaluation, six bond failures occurred, three for each composite. Kaplan-Meyer method and log-rank test (Mantel-Cox) was used for statistical analysis, and no statistically significant difference was found between the materials (p=0.999). Both Transbond XT and Transbond Plus Color Change composites had low debonding rates over the study period.

RESUMO

O objetivo do presente estudo foi avaliar in vivo a taxa de falha de braquetes metálicos colados com dois compósitos ortodônticos. Dezenove pacientes com idades entre 10,5 e 38,7 anos, que necessitavam de tratamento ortodôntico corretivo, foram selecionados para estudo. As superfícies de esmalte de segundos pré-molares a segundos pré-molares foram tratadas com Transbond Plus Self-Etching Primer (3M Unitek). Em seguida, 380 bráquetes foram colados nos dentes superiores e inferiores, como segue 190 com compósito Transbond XT (3M Unitek) (controle) e 190 com Transbond Plus Color Change (3M Unitek) (experimental), em quadrantes contralaterais. Os bráquetes colados foram fotopolimerizados por 40 s e arcos de alinhamento inicial foram inseridos. As taxas de insucesso na adesão foram registrados durante um período de seis meses. No final da avaliação, seis falhas de adesão ocorreram, três para cada composto. Para a análise estatística foram utilizados os testes de Kaplan-Meyer e log-rank (Mantel-Cox), e não houve diferença estatisticamente significante entre os materiais (p=0,999). Ambos compósitos, Transbond XT e Transbond Plus Color Change, tiveram baixas taxas de descolagem durante o período de estudo.