Shear bond strength of metal bracket to ceramics with different concentrations of hydrofluoric acid

Marcelo Piovesan DESSIMONI, Ana Paula Terossi de GODOi, Lourenço CORRER SOBRINHO, Heloisa VALDRIGHI, Giovana Cherubini VEREZIAN, Mario VEDOVELLO FILHO

Objective: The objective of this in vitro study was to evaluate the shear bond strength (SBS) of brackets bonded to feldspathic porcelain with different concentrations of hydrofluoric acid (HA), in the presence or absence of adhesive, and later the Adhe- sive Remnant Index (ARI) was evaluated. Meth- ods: 20 ceramic cylinders with different surface treatments were made: G1/G6) AF1%; G2/G7) AF2.5%; G3/G8) AF5%; G4/G9) AF7.5%; G5/G10) AF10%. After the application of the HA, silane and adhesive were used in groups G1/G2/G3/G4/G5, while silane was used in groups G6/G7/G8/G9/G10. Ten brackets were bonded (n = 20) with Transbond XT and all samples were submitted of thermal cycling. The SBS test was performed by a universal test machine and then the ARI was evaluated in an optical microscope. Data were submitted to ANOVA and Tukey test (p=0.05). Results: for HA, concentrations of 10% (6.0 ± 0.9), 7.5% (5.7 ± 0.5) and 5% (5.6 ± 0.7) promoted SBS sta- tistically equal to and greater than 2.5% (4.2 ± 1.1) and 1% (3.7 ± 0.6), respectively. It was verified that the presence of the adhesive (6.1 ± 0.9) promoted a higher SBS than its absence (4.1 ± 1.1). In ARI, score 0 predominated. Conclusion: Higher concentrations of HA and the presence of the adhesive increase the SBS of brackets to the ceramic surface, and it was verified that there was predominance of ceramic surface without bonding material.

Keywords: Orthodontic brackets. Ceramics. Hydrofluoric acid. Shear strength.

How to cite: Dessimoni MP, Godoi APT, Correr Sobrinho L, Valdrighi H, Verezian GC, Vedovello Filho M. Resistência de união de braquetes metálicos à cerâmica com diferentes concentrações de ácido fluorídrico. Rev Clín Ortod Dental Press. 2020 Abr-Maio;19(2):76-83.

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