Bond strength to surface enamel for different tooth types

Area of Science:

• Dental Materials Science
• Orthodontic Engineering
• Biomaterials

Background:

• Orthodontic fixed appliance therapy requires robust bracket adhesion to enamel.
• Bracket debonding presents clinical challenges and increased costs.
• Factors influencing enamel bond strength across different tooth types remain incompletely understood.

Purpose of the Study:

• To investigate potential variations in shear bond strength of orthodontic brackets bonded to acid-etched enamel across different human teeth.
• To establish baseline data on tooth-specific bond strengths for improved orthodontic treatment planning.

Main Methods:

• Collected 240 extracted human teeth (age 10-22) from Caucasian subjects.
• Applied standard acid-etch technique with stainless steel brackets and light-cured composite resin.
• Measured shear bond strength at 24 hours using an Instron testing machine.

Main Results:

• Tooth type significantly influenced bond strength (p<0.001).
• Highest mean bond strength observed on lower first molars; lowest on upper first molars.
• Upper arch: anterior teeth exhibited greater bond strength than posterior teeth (p<0.001).
• Lower arch: anterior teeth showed weaker bond strength than posterior teeth (p<0.001).

Conclusions:

• Findings have significant implications for dental composite bond strength testing and orthodontic treatment reliability.
• Standardized tooth selection or stratification is crucial for meaningful enamel bond strength comparisons.
• Variability in clinical bonding efficacy may be partly explained by inherent tooth-specific bond strength differences.