In vitro analysis of shear bond strength and adhesive remnant index comparing light curing and self-curing composites

Abstract

Objective: To evaluate, in vitro, the shear bond strength of self-curing (Concise TM -3M and Alpha Plast -DFL) and light-curing composites (Transbond TM XT -3M and Natural Ortho -DFL) used in orthodontics bonding, associated to Morelli metal brackets, with further analysis of adhesive remnant index (ARI) and enamel condition in scanning electron microscopy (SEM). Methods: Forty human premolars, just extracted and stored in physiologic solution 0.9 % were used. Randomly, these samples were divided in four groups: G1 group, the brackets were bonded with Concise TM -3M composite; in G2 group, Alpha Plast -DFL composite was used; in G3 group, Transbond TM XT -3M was used; in G4 group, Natural Ortho -DFL composite was used. These groups were submitted to shear strength tests in universal testing machine, at 0.5 mm per minute speed. Results: Statistical difference between G3 and G4 groups was recorded, as G4 showing higher strength resistance than G3. In the other hand, there were no statistical differences between G1, G2 and G3 and G1, G2 and G4 groups. ARI analysis showed that there was no statistical difference between the groups, and low scores were recorded among then. The scanning electron microscopy (SEM) analysis revealed the debonding spots and the enamel surface integrity. Conclusions: Shear bond strength was satisfactory and similar between the composites, however Natural Ortho -DFL revealed best comparing to Transbond TM XT -3M. Keywords: Composite resins. Shear strength. Scanning electron microscopy.How to cite this article: Neves MG, Brandão GAM, Almeida HA, Brandão AMM, Azevedo DR. In vitro analysis of shear bond strength and adhesive remnant index comparing light-curing and self-curing composites. Dental Press J Orthod. 2013 May-June;18(3):124-9.» The authors report no commercial, proprietary or financial interest in the products or companies described in this article. Objetivo: avaliar in vitro a resistência ao cisalhamento de compósitos autopolimerizáveis (Concise e Alpha Plast) e fotopolimerizáveis (Transbond XT e Natural Ortho) utilizados na colagem de braquetes metálicos da marca Morelli, analisando o índice de adesivo remanescente (ARI) e da integridade da superfície do esmalte por meio de microscopia eletrônica de varredura (MEV). Métodos: foram utilizados 40 pré-molares humanos extraídos. As raízes dos dentes foram incluídas em gesso-pedra especial, no interior de tubos de PVC usados para a confecção dos corpos de prova. Esses corpos de prova foram divididos em quatro grupos: grupo G1, braquetes associados ao compósito Concise; grupo G2, braquetes associados ao compósito Alpha Plast; grupo G3, braquetes associados ao compósito Transbond XT; e grupo G4, braquetes associados ao compósito Natural Ortho. Os grupos foram submetidos ao teste de cisalhamento em máqui-na universal de ensaios, a uma velocidade de 0,5mm por minuto. Resultados: houve diferença estatística entre os grupos G3 e G4, sendo os valores de G4 superiores; no entanto, não foram encontradas diferenças estatisticamente significativa...

Comparison of Shear Bond Strength of MIM Technology Brackets with Conventional and Rail-Shaped Mesh Bases: An In Vitro Study

“…This ARI classification evaluates the amount of resin adhered to the tooth, after removal of the bracket, and suggests several degrees of susceptibility to enamel fracture. The ideal is to achieve high scores on the ARI (greater amount of material adhered to the tooth) to maintain the integrity of the enamel [17].…”

Prototype to measure bracket debonding force in vivo

“… 16 , 17 Bond strength values above 10 MPa are potentially dangerous since they may cause enamel fractures during bracket debonding. 18 However, it is difficult to establish a numerical value because these values depend on several factors, such as the condition of the substrate, 19 the material involved, 20 the devices chosen for the test, 21 cure time, 22 and the location where force is applied to the bracket. 23 …”