Effect of autoclaving on the fracture torque of mini‐implants used for orthodontic anchorage

Abstract

Objective: To evaluate the influence of autoclave sterilization on the fracture torque of five commercially available mini‐implants used for orthodontic anchorage.

Design: In vitro laboratory study.

Materials and methods: Ten mini‐implants from each of five different manufacturers were submitted to one cycle of autoclave sterilization and tested, compared to their control groups – consisting of 10 as‐received mini‐implants each – to assess their fracture torque values. The mini‐implants, connected to a digital torque gauge perpendicularly positioned to the bone surface, were inserted into swine femoral cortical bone segments until their fracture.

Outcome measures: Maximum torque values.

Statistical analysis: A two‐way ANOVA to detect differences between implant products and the allocation group and one‐way ANOVA with the Tukey’s honestly significant difference (HSD) post hoc test among autoclaved groups and among control groups separately to detect differences between manufacturers.

Results: The effect of the autoclaving process was not significant (P = 0·411). The manufacturer factor, however, was significant (P<0·001). The one‐way ANOVA with the Tukey’s HSD post hoc test results showed statistically significant differences between control groups.

Conclusion: The autoclave sterilization of the mini‐implants tested in this study did not affect their resistance to fracture; however, the mini‐implants from different manufacturers presented with statistically significant differences in their resistance to fracture.

Keywords:

• Autoclave sterilization
• orthodontics
• mini‐implants
• fracture torque

Acknowledgments

The authors would like to thank Matheus Pithon for providing the device used in the mechanical test.