In vitro bracket bond strength to acid-etched or air-abraded enamel

Area of Science:

• Orthodontic materials science
• Dental adhesion research
• Enamel surface preparation techniques

Background:

• Orthodontic bracket debonding is a clinical concern.
• Enamel preparation methods significantly impact bracket bond strength.
• Evaluating novel surface treatments is crucial for improving orthodontic treatment outcomes.

Purpose of the Study:

• To evaluate the in vitro bond strength of orthodontic brackets on enamel prepared with air abrasion versus traditional acid etching.
• To assess the efficacy of a dentin bonding agent in enhancing bond strength on air-abraded enamel surfaces.

Main Methods:

• Enamel surfaces were prepared using either 38% phosphoric acid etching or air abrasion (50-micron particles, 120 psi).
• A dentin bonding agent was applied to some surfaces after preparation.
• Orthodontic brackets were bonded using a light-cured adhesive, and shear bond strength was measured.
• Bond failure sites were analyzed under magnification.

Main Results:

• Traditional acid-etched enamel demonstrated significantly higher shear bond strength compared to air-abraded enamel.
• The addition of a dentin bonding agent did not significantly improve bond strength on acid-etched surfaces.
• Air abrasion resulted in very low bond strengths across all tested conditions.

Conclusions:

• Air abrasion enamel preparation yields clinically unacceptable bond strength for orthodontic brackets.
• Acid etching remains the superior method for preparing enamel surfaces for orthodontic bracket bonding.
• Further research is needed to explore alternative surface preparation techniques if air abrasion is to be considered.