Resistance to sliding with 3 types of elastomeric modules.
BACKGROUND
Super Slick (TP Orthodontics, LaPorte, Ind), a polymeric-coated ligature, has recently been introduced to the orthodontic market. The manufacturer claims it will significantly reduce friction. The purposes of this study were to determine whether Super Slick modules show lower friction than round and rectangular modules and to put the frictional forces into perspective with a self-ligating bracket.


METHODS
Maxillary premolar, stainless steel, self-ligating, and monocrystalline brackets with .022-in slots were used with straight lengths of .018-in and .019 x .025-in stainless steel wires. Buccal segment models were set up with 1 molar band and 2 premolar brackets for each test group: self-ligating brackets with the slide closed, self-ligating brackets with the slide open, and monocrystalline brackets. The latter 2 groups were tested with all 3 types of elastomeric module. Each setup was tested both under dry conditions and after soaking in a water bath for 1 hour.


RESULTS
The self-ligating brackets demonstrated virtually zero friction with each combination of wire and environmental condition. When the different bracket and elastomeric module combinations were compared, significant differences were observed. In all but 2 combinations, round modules provided the least resistance to sliding and rectangular modules the greatest, with Super Slick modules in between the 2. The self-ligating bracket provided the least resistance to sliding of all the bracket/ligation combinations and almost entirely eliminated friction under the conditions of this experiment.


CONCLUSIONS
Super Slick modules demonstrated greater resistance to sliding than conventional round modules, but not rectangular. Self-ligating brackets provided the least resistance to sliding of all bracket/ligation combinations and were the only method that almost entirely eliminated friction. The .018-in and .019 x .025-in wires exhibited similar friction in the dry state, but, when wet, the .018-in wire produced less friction. Ceramic brackets demonstrated greater resistance to sliding than stainless steel brackets. Lubrication reduced the friction with .018-in wires and increased it for .019 x .025-in wires.
Griffiths
Helen Sylvia
HS
Bristol Dental Hospital and School, Lower Maudlin Street, Bristol BS1 2LY, UK.
Sherriff
Martyn
M
Ireland
Anthony John
AJ
D002516:Ceramics; D020099:Coated Materials, Biocompatible; D003799:Dental Stress Analysis; D020724:Elastomers; D017276:Friction; D008422:Materials Testing; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D013193:Stainless Steel; D018709:Statistics, Nonparametric
D020099:Coated Materials, Biocompatible; D020724:Elastomers; D013193:Stainless Steel