The korean journal of orthodontics (대한치과교정학회지)

The Korean Association Of Orthodontists (대한치과교정학회)
권호 표지

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

국산 폴리카보네이트 브라켓 윙의 파절 강도에 관한 연구

  • Sun, Min-Kyu (School of Dentistry and Dental Science Research Institute, Chonnam National University) ;
  • Lee, Ki-Heon (Department of Orthodontics, Chonnam National University Hospital) ;
  • Hwang, Hyeon-Shik (Department of Orthodontics, Chonnam National University Hospital)
  • 선민규 (전남대학교 치과대학 교정학교실) ;
  • 이기헌 (전남대학교 치의학연구소, 치과대학 교정학교실) ;
  • 황현식 (전남대학교 치의학연구소, 치과대학 교정학교실)
  • Published : 2007.06.30
Download PDF
⟨ Previous Next ⟩

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 $5^{\circ}C\;and\;55^{\circ}C$. 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.

심미적 교정장치에 대한 요구가 증가함에 따라 폴리카보네이트 브라켓에 대한 관심이 커지고 있으나 이는 윙이 쉽게 파절되는 문제를 가지고 있다. 본 연구는 새롭게 개발된 국산 폴리카보네이트 브라켓의 윙의 파절 강도를 측정하여 임상에서 사용할 수 있는지 평가하기 위하여 시행되었다. 실험군으로 Alice 브라켓을, 대조군으로 Spirit MB 브라켓을 사용하여 상온에서 방치한 경우와 $5^{\circ}C$와 $55^{\circ}C$에서 2,000회 열변환 시킨 경우로 나눈 다음, 만능시험기를 이용하여 브라켓 윙의 파절 강도를 측정하고 비교 분석하였다. 연구 결과 상온에서 방치한 경우와 열변환 시킨 경우 모두에서 Spirit MB 브라켓에 비하여 Alice 브라켓 윙의 파절 강도가 통계적으로 유의하게 높은 것으로 나타나 Alice 브라켓이 윙의 파절 강도 면에서 임상적으로 사용 가능함을 시사하였다.

Keywords

References

  1. Phillips HW. The advent of ceramics. J Clin Orthod 1988;22:69-70
  2. Dobrin RJ, Kamel IL, Musich DR. Load-deformation characteristics of polycarbonate orthodontic brackets. Am J Orthod 1975;67:24-33 https://doi.org/10.1016/0002-9416(75)90126-8
  3. Swartz ML. Ceramic brackets. J Clin Orthod 1988;22:82-8
  4. Gottlieb EL, Nelson AH, Vogels DS 3rd. 1990 JCO study of orthodontic diagnosis and treatment procedures. I. results and trends. J Clin Orthod 1991;25: 145-56
  5. Scott GE Jr. Fracture tougllness and surface cracks--the key to understanding ceramic brackets. Angle Orthod 1988;58:5-8
  6. Rhodes RK, Duncanson MG Jr, Nanda RS, Currier GF. Fracture strengths of ceramic brackets subjected to mesial-distal archwire tipping forces. Angle Orthod 1992;62:67-76
  7. Douglass JB. Enamel wear caused by ceramic brackets. Am J Orthod Dentofacial Orthop 1989;95:96-8 https://doi.org/10.1016/0889-5406(89)90387-9
  8. Viazis AD, DeLong R, Bevis RR, Rudney JD, Pintado MR. Enamel abrasion from ceramic orthodontic brackets under an artificial oral environment. Am J Orthod Dentofacial Orthop 1990;98:103-9 https://doi.org/10.1016/0889-5406(90)70003-U
  9. Viazis AD, Chabot KA, Kucheria CS. Scanning electron microscope (SEM) evaluation of clinical failures of single crystal ceramic brackets. Am J Orthod Dentofacial Orthop 1993;103:537-44 https://doi.org/10.1016/0889-5406(93)70094-5
  10. Feldner JC, Sarkar NK, Sheridan JJ, Lancaster DM. In vitro torque-deformation characteristics of orthodontic polycarbonate brackets. Am J Orthod Dentofacial Orthop 1994;106:265-72 https://doi.org/10.1016/S0889-5406(94)70046-X
  11. Son JH, Hwang HS, Change of frature mode of orthodontic resin bracket wings under water immersion and thermocycling. Korean J Orthod 2000;30:475-81
  12. Rains MD, Chaconas SJ, Caputo AA, Rand R. Stress analysis of plastic bracket configurations. J Clin Orthod 1977;11:120-5
  13. Johnson G, Walker MP, Kula K. Fracture strength of ceramic bracket tie wings subjected to tension. Angle Orthod 2005;75:95-100
  14. Aird JC, Durning P. Fracture of polycarbonate edgewise brackets: a clinical and SEM study. Br J Orthod 1987;14:191-5 https://doi.org/10.1179/bjo.14.3.191