Shear Bond Strength Comparison of Three Different Orthodontic Adhesives

Materials and Method: Sixty bovine incisor teeth were collected and teeth were randomly divided into three groups of 20. In group 1, lower incisor brackets were bonded with Eagle Bond (American Orthodontics, Sheboygan, WI, USA). In group 2, Transbond XT Light Cure Adhesive (3M Unitek, Monrovia, Calif, USA) was used. Group 3 used a multi-purpose adhesive system, Resinomer (Bisco, Inc., Schaumburg, IL, USA) combined with a 5th generation intermediate resin (One-Step +). All the specimens were light cured and stored in water at 37 ºC for 48 hours. Debonding was performed using an universal testing machine with a shear blade.

Results: The mean shear bond strength was 18.9 MPa for group 1, 19.9 MPa for group 2 and 24.9 MPa for group 3. The results of one-way analysis of variance showed a statistically significant difference in bond strength among the groups. Post Hoc Tukey multiple comparison test revealed that the results of group 3 differed significantly from groups 1 (p<0.001) and 2 (p<0.01). There was no statistically significant difference between group 1 and 2 (p>0.05). Chi square test revealed significant difference in ARI scores between group 1 and 3 (p<0.001).

Conclusion: All three adhesives appear to provide clinically acceptable bond strength for orthodontic use. Bond strength of Resinomer - One Step + system was found superior to Eagle Bond and Transbond. However bonding brackets with Eagle Bond resulted in less residual adhesive remaining on the teeth.