Bond strength of orthodontic brackets using different light and self-curing cements

Area of Science:

• Dental materials science
• Orthodontic research
• Biomaterials testing

Background:

• Accurate shear bond strength is crucial for successful orthodontic bracket adhesion.
• Evaluating novel bonding agents and techniques is essential for improving clinical outcomes.
• Understanding bond failure modes aids in refining bracket placement and debonding procedures.

Purpose of the Study:

• To assess the shear bond strength of stainless steel orthodontic brackets bonded to human premolar teeth using various materials and techniques.
• To compare the efficacy of chemically cured and light-cured composite resins against glass ionomer cements.
• To analyze the influence of enamel etching on bond strength and failure characteristics.

Main Methods:

• Fifty extracted human premolar teeth were divided into five groups, each using a different bonding agent (System One, Light Bond, Vivaglass Cem, Fuji Ortho LC with/without etching).
• Brackets were bonded, specimens stored, and thermocycled before debonding using an Instron machine to measure shear bond strength.
• Bond failure sites were analyzed using stereomicroscopy and scanning electron microscopy.

Main Results:

• System One (chemically cured composite resin) exhibited the highest shear bond strength.
• Light Bond (light-cured composite resin) and Fuji Ortho LC with acid etching demonstrated clinically acceptable bond strengths.
• Fuji Ortho LC and Vivaglass Cem resulted in minimal enamel surface alteration post-debracketing.

Conclusions:

• Chemically cured composite resins may offer superior bond strength for orthodontic brackets.
• Light-cured glass ionomer cement with proper enamel etching provides reliable clinical bond strength.
• Material selection impacts both bond strength and the condition of the enamel post-debonding.