An Ex Vivo Study to Investigate Bond Strengths of Different Tooth Types

Abstract

This study aimed to identify the presence and pattern of differences in ex vivo shear bond strength between tooth types when bonding orthodontic brackets using Right-On®, and took the form of a prospective laboratory study of bond strength on different tooth types, at the Newcastle University Dental School Materials Science Laboratory, 1997–1999.

  Ex vivo bond strength testing was undertaken using the technique described by Fox et al. (BJO 18, 125–130, 1991) on a total of 120 extracted incisor, canine, and premolar teeth of each dental arch. Analysis was by one-way ANOVA with Tukey's pairwise comparisons, and by Weibull Analysis. Shear stress to failure (measured in MPa) was recorded on Instron® 5567 universal testing machine.

  Significant differences in mean bond strength existed between different tooth-type series. Canine (upper 12•3, lower 12•1) and premolar (upper 11•9, lower 10•9) teeth exhibited higher strengths than incisors (upper 6•9, lower 9•0).

  The results of this study confirm that ex vivo bond strength is not uniform across all teeth.

Keywords:

• Orthodontic Bonding
• Shear Bond Strength

Acknowledgments

The authors wish to thank Professor J. F. McCabe and his staff for allowing access to the dental materials science laboratory at Newcastle Dental School, and for their help with the Weibull statistics. We also wish to thank the staff of the Oral and Maxillofacial Surgery Department at Middlesbrough General Hospital for collecting the extracted teeth used in this study.