Static frictional resistances of polycrystalline ceramic brackets with metal slot inserts

Rajakulendran, Janahan; Jones, Steven

doi:10.2478/aoj-2006-0016

Abstract

Aims

To compare the static frictional resistances of polycrystalline ceramic brackets with a gold slot insert (Desire), a stainless steel slot insert (Clarity), a conventional polycrystalline ceramic bracket (Transcend 6000) and a stainless steel bracket (Ultratrimm).

Methods

Twenty five brackets of each type were tested by sliding against straight lengths of 0.019 x 0.025 inch rectangular stainless steel wire. During the tests the brackets and wire were lubricated with artificial saliva. Static frictional forces at three different binding angulations (0, 5 and 10 degrees) were measured for all brackets.

Results

Statistically significant increases in static frictional resistance were found as the bracket/wire angulation increased from 0 through 5 to 10 degrees for all bracket types. At angulations below the critical binding angle the Ultratrimm brackets produced the greatest friction and the Transcend 6000 brackets produced the least friction. As the angulation increased the Transcend 6000 brackets produced greater friction than the other brackets. At the highest angulation (10 degrees), the Ultratrimm brackets produced significantly less friction and the Transcend 6000 brackets produced significantly more friction than the other brackets. The Desire and Clarity brackets produced comparable results: there were no statistically significant differences between these two brackets for static friction at any of the angulations.

Conclusions

Polycrystalline ceramic brackets with either stainless steel or gold slot inserts produced similar static frictional resistances to sliding. At binding angulations, the brackets with inserts demonstrated consistently lower static frictional resistances than a conventional ceramic bracket.

References

Drescher D, Bourauel C, Schumacher H. Frictional forces between bracket and arch wire. Am J Orthod Dentofacial Orthop 1989;96:397–404.
Search in Google Scholar Back to article
Birnie D. Ceramic brackets. Br J Orthod 1990;17:71–4.
Search in Google Scholar Back to article
Gottlieb EL, Vogels DS. JCO Orthodontic practice study: Part 1 – Trends. J Clin Orthod 1984;18:167–73.
Search in Google Scholar Back to article
Angolkar PV, Kapila S, Duncanson MG Jr, Nanda RS. Evaluation of friction between ceramic brackets and orthodontic wires of four alloys. Am J Orthod Dentofacial Orthop 1990;98:499–506.
Search in Google Scholar Back to article
Kusy RP, Whitley JQ. Coefficients of friction for arch wires in stainless steel and polycrystalline alumina bracket slots. 1: The dry state. Am J Orthod Dentofacial Orthop 1990;98: 300–12.
Search in Google Scholar Back to article
Dickson J, Jones SP. Frictional characteristics of a modified ceramic bracket. J Clin Orthod 1996;30:516–18.
Search in Google Scholar Back to article
Loftus BP, Artun J, Nicholls JI, Alonzo TA, Stoner JA. Evaluation of friction during sliding tooth movement in various bracket – arch wire combinations. Am J Orthod Dentofacial Orthop 1999;116:336-45.
Search in Google Scholar Back to article
Kusy RP, Whitley JQ. Frictional resistance of metal-lined ceramic brackets versus conventional stainless steel brackets and development of 3-D frictional maps. Angle Orthod 2001;71:364–74.
Search in Google Scholar Back to article
Hood YS. An ex-vivo comparative study into the static frictional resistance of a new polyoxymethylene bracket. MSc Thesis, University of London, 2001.
Search in Google Scholar Back to article
Altman DG. Statistics in Practice. British Medical Association, London, 1982.
Search in Google Scholar Back to article
Keith O, Jones SP, Davies EH. The influence of bracket material, ligation force and wear on frictional resistance of orthodontic brackets. Br J Orthod 1993;20:109–15.
Search in Google Scholar Back to article
Kusy RP, Whitley JQ. Effects of sliding velocity on the coefficients of friction in a model orthodontic system. Dent Mater 1989;5:235–40.
Search in Google Scholar Back to article
Kusy RP, Whitley JQ. Assessment of second-order clearances between orthodontic arch wires and bracket slots via the critical contact angle for binding. Angle Orthod 1999;69: 71–80.
Search in Google Scholar Back to article
Thorstenson GA, Kusy RP. Resistance to sliding of self-ligating brackets versus conventional stainless steel twin brackets with second-order angulation in the dry and wet (saliva) states. Am J Orthod Dentofacial Orthop 2001;120:361–70.
Search in Google Scholar Back to article
Downing A, McCabe J, Gordon P. A study of frictional forces between orthodontic brackets and arch wires. Brit J Orthod 1994;21:349–57.
Search in Google Scholar Back to article
Articolo LC, Kusy K, Saunders CR, Kusy RP. Influence of ceramic and stainless steel brackets on the notching of archwires during clinical treatment. Eur J Orthod 2000;22: 409–25.
Search in Google Scholar Back to article
Articolo LC, Kusy RP. Influence of angulation on the resistance to sliding in fixed appliances. Am J Orthod Dentofacial Orthop 1999;115:39–51.
Search in Google Scholar Back to article
Read-Ward GE, Jones SP, Davies EH. A comparison of selfligating and conventional orthodontic bracket systems. Br J Orthod 1997;24:309–17.
Search in Google Scholar Back to article