Bonding brackets to porcelain--in vitro study

Area of Science:

• Dental Materials Science
• Orthodontic Adhesion
• Biomaterials Engineering

Background:

• Orthodontic bracket debonding from porcelain restorations can cause iatrogenic damage.
• Effective bonding protocols are crucial for successful orthodontic treatment involving porcelain substrates.
• Evaluating surface treatments for porcelain is essential to optimize bracket adhesion and minimize substrate damage.

Purpose of the Study:

• To investigate the in vitro shear bond strength of orthodontic brackets bonded to porcelain.
• To assess the mode of fracture after debonding following different porcelain surface treatments.
• To determine the efficacy of silane/composite bonding on feldspathic porcelain.

Main Methods:

• Eighty-eight feldspathic porcelain samples were divided into four groups: intact, diamond bur roughened, 10% hydrofluoric acid etched, and aluminum oxide sandblasted.
• All specimens were treated with silane (Scotchprime) and bonded with Concise composite.
• Shear bond strength was tested at a crosshead speed of 1 mm/min, and fracture modes were analyzed.

Main Results:

• All tested surface treatments resulted in bond strengths adequate for orthodontic forces.
• No statistically significant differences in shear bond strength were observed between the groups (p > 0.05).
• A higher incidence of porcelain fractures was noted with deglazed porcelain surfaces.

Conclusions:

• The silane/composite bonding procedure demonstrates adequate shear bond strength for orthodontic brackets on porcelain.
• Careful material selection is important, as some surface treatments may increase the risk of porcelain fracture during debonding.
• The findings suggest that mechanical preparation may not be necessary when using appropriate silane and composite systems.