Shear bond strength of orthodontic brackets to aged resin composite surfaces: effect of surface conditioning

ABSTRACT Aim To evaluate and compare the shear bond strength of metal brackets bonded to ceramic surfaces using different conditioning methods and to assess the site of bond failure after debonding. Materials and methods A total of 70 ceramic surfaces were produced with uniform shape, size and composition. The samples were divided into 7 groups (each of 10 samples). Group 1 was the control group (untreated surface); in group 2 the surface were roughened with a diamond bur; in group 3 the surface were etched with hydrofluoric acid; in group 4 the surfaces were sandblasted; in group 5 the surfaces roughened with bur and silane applied; in group 6 the surfaces were etched with hydrofluoric acid and silane applied and in group 7 the surfaces were sandblasted and silane applied. To all the above groups, metal orthodontic brackets were bonded with light cure adhesive. The brackets were later stored in artificial saliva and incubated at 37°C (24 hours). The samples were then subjected to shear bond strength test using an Instron universal testing machine. The debonded porcelain surfaces were then studied under stereomicroscope to assess site of bond failure. Results Sandblasting the ceramic surface and silane application showed the highest bond strength. Stereomicroscope examination after debonding showed that the bond failure is at bracket-adhesive interface in four groups namely hydrofluoric acid, sandblasting, hydrofluoric acid with silane and sandblasting with silane. Conclusion Sandblasting with silane combination produced the highest shear bond strength, so it is a clinically suitable method for bonding orthodontic metal brackets onto ceramic surface. Clinical relevance Bonding orthodontic brackets to ceramic crowns of patients has been a tough task. In this study, different conditioning methods were used to treat the ceramic surfaces before bonding. The results showed that sandblasting the ceramic surface prior to application of silane produced the highest shear bond strength which is clinically suitable to reduce bond failures. How to cite this article Girish PV, Dinesh U, Bhat CSR, Shetty PC. Comparison of Shear Bond Strength of Metal Brackets Bonded to Porcelain Surface using Different Surface Conditioning Methods: An in vitro Study. J Contemp Dent Pract 2012;13(4):487-493.

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Effect of Surface Conditioning Methods on Shear Bond Strength of Various Base/Lining Materials to Composite

Korean Journal of Dental Materials ◽

10.14815/kjdm.2011.09.38.3.239 ◽

2011 ◽

Keyword(s):

Bond Strength ◽

Shear Bond Strength ◽

Surface Conditioning ◽

Effect Of Surface

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Influence of surface treatment on shear bond strength of orthodontic brackets

Dental Press Journal of Orthodontics ◽

10.1590/s2176-94512013000300010 ◽

2013 ◽

Vol 18 (3) ◽

pp. 54-62 ◽

Cited By ~ 1

Author(s):

Ione Helena Vieira Portella Brunharo ◽

Daniel Jogaib Fernandes ◽

Mauro Sayão de Miranda ◽

Flavia Artese

Keyword(s):

Bond Strength ◽

Aluminum Oxide ◽

Sodium Bicarbonate ◽

Surface Treatment ◽

Hydrofluoric Acid ◽

Shear Bond Strength ◽

Resin Composite ◽

Orthodontic Brackets ◽

Treatment Methods ◽

Hybrid Resin

INTRODUCTION: The shear bond strength of orthodontic brackets bonded to micro-hybrid and micro-particulate resins under different surface treatment methods was assessed. METHODS: Two hundred and eighty test samples were divided into 28 groups (n = 10), where 140 specimens were filled with Durafill micro-particulate resin and 140 with Charisma composite. In 140 samples, a coupling agent (silane) was applied. The surface treatment methods were: Phosphoric and hydrofluoric acid etching, sodium bicarbonate and aluminum oxide blasting, stone and burs. A Universal Instron Machine was used to apply an occlusal shear force directly to the resin composite bracket surface at a speed of 0.5 mm/min. The means were compared using analysis of variance and multivariate regression to assess the interaction between composites and surface treatment methods. RESULTS: Means and standard deviations for the groups were: Sodium bicarbonate jet 11.27±2.78; burs 9.26±3.01; stone 7.95±3.67; aluminum oxide blasting 7.04±3.21; phosphoric acid 5.82±1.90; hydrofluoric acid 4.54±2.87, and without treatment 2.75±1.49. An increase of 1.94 MPa in shear bond strength was seen in Charisma groups. Silane agent application reduced the Charisma shear bond strength by 0.68 Mpa, but increased Durafill means for bicarbonate blasting (0.83), burs (0.98) and stone drilling (0.46). CONCLUSION: The sodium bicarbonate blasting, burs and stone drilling methods produced adequate shear bond strength and may be suitable for clinical use. The Charisma micro hybrid resin composite showed higher shear bond means than Durafill micro particle composite.

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