Effects of clinical use and sterilization on surface topography and surface roughness of three commonly used types of orthodontic archwires.
OBJECTIVE
To evaluate the changes in surface topography and roughness of stainless steel (SS), nickel-titanium and beta-titanium (β-Ti) archwires after clinical use and sterilization.


METHODS
Thirty wires each of SS, nitinol, and β-Ti (3M Unitek) were tested in as received, as received and autoclaved, and clinically retrieved then autoclaved conditions.


METHODS
A sterilization protocol of 134°C for 18 min was performed using an autoclave. Surface topography of specimens from each subgroup was examined using an environmental scanning electron microscope (ESEM model Quanta 200, The Netherlands) at ×100, ×1000, and ×2500 magnifications. Surface roughness was measured using arithmetic mean roughness (Ra) values obtained from optical profilometric scanning (Taylor Hobson, Leicester, UK).


METHODS
Data were analyzed by one-way analysis of variance and Tukey's post-hoc procedures.


RESULTS
Scanning electron microscope images revealed an increase in surface irregularities in SS and nitinol wires after clinical use. There was a significant increase in Ra values of SS orthodontic wires after intra-oral exposure (P = 0.0002).


CONCLUSIONS
Surface roughness of SS wires increased significantly after clinical use. Autoclave sterilization did not affect considerably on surface characteristics of any archwire.
Department of Orthodontics and Dentofacial Orthopedics, Krishnadevaraya College of Dental Sciences, Bengaluru, Karnataka, India.
Joji
J
Isac
B S
BS
Chandrashekar
S
S
Mahendra
C M
CM
Mahesh
Bala Mohan
BM
Shetty
A V
AV
Arun
D006801:Humans; D008422:Materials Testing; D009532:Nickel; D009969:Orthodontic Wires; D013193:Stainless Steel; D013242:Sterilization; D013499:Surface Properties; D014025:Titanium
C023988:beta titanium; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium