Debonding characteristics of a polymer mesh base ceramic bracket bonded with two different conditioning methods

Area of Science:

• Orthodontics
• Biomaterials Science
• Dental Materials

Background:

• Ceramic brackets offer aesthetic advantages in orthodontics.
• Ensuring strong bracket adhesion while facilitating clean debonding is crucial for enamel preservation.
• Surface conditioning methods significantly influence bracket bond strength and debonding characteristics.

Purpose of the Study:

• To compare the shear bond strength (SBS) of ceramic brackets using conventional etching versus a self-etching primer.
• To evaluate the debonding characteristics and adhesive remnant index (ARI) after different conditioning methods.
• To assess polymer mesh base fractures and their implications for debonding strategies.

Main Methods:

• 100 human premolars were bonded with InVu Readi-Base ceramic brackets using either conventional acid etching (CM) or Transbond Plus self-etching primer (SEP).
• SBS testing was conducted, followed by debonding (plier or machine) after 1000 thermocycling cycles.
• Adhesive Remnant Index (ARI) assessed residual adhesive on enamel; Weibull analysis and statistical tests were employed.

Main Results:

• No significant difference in SBS was found between CM (9.22 MPa) and SEP (9.04 MPa) groups (P=0.684).
• Significant differences in ARI scores were observed between machine and plier debonding for both groups (P
• Polymer mesh base fractures occurred in both groups without significant difference, but most specimens showed adhesive remaining on enamel, protecting the surface.

Conclusions:

• Both conventional etching and self-etching primer provide comparable shear bond strength for ceramic brackets.
• Debonding with pliers resulted in a more favorable adhesive distribution on the enamel surface compared to machine debonding.
• While enamel protection is enhanced, potential base fractures at the ceramic/polymer interface may require adjusted debonding techniques.