Korean J Orthod.  2007 Jun;37(3):204-211.

Fracture strength of tie wings in a newly-developed polycarbonate bracket

• Sun MK
• Lee KH
• Hwang HS

Abstract

OBJECTIVE
With an increasing demand for esthetic orthodontic appliances, the interest in polycarbonate brackets has also increased. However, polycarbonate bracket wings are prone to fracture. The purpose of this study was to evaluate the clinical usefulness of a newly-developed polycarbonate bracket by measuring the fracture strength of bracket tie wings.
METHODS
Alice (K.M. Daicom, Seoul, Korea) and Spirit MB (Ormco, Glendora, CA, USA) brackets were used as an experimental and control bracket respectively. Each bracket group was divided into halves. One half was untreated and the other half was treated with 2,000 times of thermocycling between 5 degrees C and 55 degrees C. The fracture strength of the wing was measured by a universal testing machine.
RESULTS
Alice bracket wings showed significantly higher strength than Spirit MB bracket wings in both untreated and thermocycled bracket cases.
CONCLUSION
Alice brackets may be used clinically in terms of the strength of bracket wings.

Keyword

Polycarbonate bracket; Fracture strength; Thermocycling; Universal testing machine

MeSH Terms

Orthodontic Appliances
Seoul