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Shear Bond Strength of Metal Brackets to Porcelain Using a Universal Adhesive
Amin Golshah1, Nahid Mohamadi2, Farshad Rahimi1
1Department of Orthodontics, Kermanshah University of Medical Sciences, Kermanshah, Iran.
Introduction:
Bracket bonding to porcelain has high failure rate compared to bonding to enamel.
Aim:
This study aimed to assess the shear bond strength (SBS) of metal brackets to porcelain using a universal adhesive.
Material And Methods:
In this in vitro experimental study, 40 porcelain blocks (1x1x1 cm3)were divided into four groups (n=10). The porcelain surfaces were etched with 10% hydrofluoric (HF) acid and bonded to metal brackets using Transbond XT composite and the following bonding protocols: Transbond XT bonding agent alone in group 1, silane plus Transbond XT bonding agent in group 2, silane plus universal adhesive (G-Premio bond) in group 3 and universal adhesive alone in group 4. The SBS was measured using a universal testing machine at a crosshead speed of 1 mm/minute. Fracture surfaces were evaluated under a stereo microscope, and the adhesive remnant index (ARI) scores were determined.
Results:
The highest and the lowest SBS values were noted in groups 3 (17.06±2.58 MPa) and 4 (9.85±4.76 MPa), respectively. Type of adhesive had no significant effect on SBS (P=0.611). However, the effect of application of silane on SBS was significant (P=0.000). Groups subjected to the application of silane showed higher SBS values than others. The mode of failure was mainly adhesive in groups 2 and 3, and adhesive and mixed in groups 1 and 4. The difference in ARI scores was statistically significant (P=0.016).
Conclusion:
Universal adhesive and Transbond XT were not significantly different in SBS. However, application of silane significantly increased the bond strength.
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