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Author

Spencer R

Bio: Spencer R is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 89 citations.

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Journal ArticleDOI
TL;DR: Optimal use of these orthodontic wires can be made by carefully selecting the appropriate wire type and size to meet the demands of a particular clinical situation.

285 citations

Journal ArticleDOI
TL;DR: A friction-testing assembly simulating three-dimensional tooth rotations was constructed to study factors affecting friction magnitude and recommends the application of 0.016 x 0.022 inch stainless steel wire combined with a medium or wide bracket for an arch-guided mechanism with an 0.018 inch slot.

269 citations

Journal ArticleDOI
TL;DR: The wire size-alloy interaction on the magnitude of bracket-wire friction was statistically significant (p less than 0.005), and with most wire sizes and alloys, narrow single brackets were associated with lower amounts of friction than wider brackets were.

242 citations

Journal ArticleDOI
TL;DR: In vitro and clinical investigation found that self-ligating bracket systems displayed a significantly lower level of frictional resistance, dramatically less chairtime for arch wire removal and insertion, and promoted improved infection control, when compared with polyurethane elastomeric and stainless steel tie wire ligation for ceramic and metal twin brackets.

227 citations

Journal ArticleDOI
TL;DR: The selection of bracket design, wire material, and wire cross-section significantly influences the forces acting in a continuous arch system.
Abstract: Orthodontic tooth movement can be regarded as teeth sliding on a wire like pearls on a string, the force being supplied by springs or elastics. The movement implies friction between wire and bracket, taking up part of the force and leaving an uncontrolled amount to act on the teeth. The friction is likely to depend on bracket construction and wire material. Therefore, in this investigation the friction of self-ligating brackets and beta-titanium wires was evaluated, as opposed to more conventional configurations. Carried by low-friction linear ball bearings, a bracket was made to slide along an out-stretched archwire with minimal (and known) basic friction, either parallel or at an angle to the wire. Two self-ligating brackets we reused in their closed position without any normal force. Friction was tested against four wires: stainless steel and beta-titanium, both in round and rectangular cross-sections. The force used to overcome friction and to move the bracket was measured on a testing machine at 10 mm/min, and the basic friction was subtracted. The results show that round wires had a lower friction than rectangular wires, the beta-titanium wires had a markedly higher friction than stainless steel wires, and friction increased with angulation for all bracket/wire combinations. The self-ligating brackets had a markedly lower friction than conventional brackets at all angulations, and self-ligating brackets, closed by the capping of a conventional design, exhibited a significantly lower friction than self-ligating brackets closed by a spring. The selection of bracket design, wire material, and wire cross-section significantly influences the forces acting in a continuous arch system.

204 citations