No abstract available.
Orthodontic Wires*

The bonded orthodontic retainer constructed from composite and multistrand orthodontic wire provides an esthetic and efficient system for maintained retention. This study was designed to measure shear bond strength of bonded retainers and to suggest a optimal combination of a multistrand wire and bonding method used when bonded retainer was fabricated. 160 sound maxillary and mandibular premolars were used for 80 test samples. After Uniformizing bonding area, length of wire, and thickness of composite, multistrand wire was bonded to fabricated a bonded retainer by direct or indirect bonding method. Shear bond strength and extension length of each sample were measured by a universal testing machine. The results of this study were as follows: 1. In vitro shear bond testing found 6-stranded, 0.0155 inch wires to have the largest shear bond strength and 3-stranded, 0.0195 inch wires to have the least shear bond strength. But, These difference was not statistically significant(p<0.05). 2. In vitro extension testing found 3-stranded, 0.0155 inch wires to have the largest extension length and 3-stranded, 0.0195 inch wires to have the least extension length(p<0.05). The larger diameter wire was used, the larger extension length was shown. But, the strand of wire is not related to the extension length of wire. 3. In comparison with direct bonding method, larger shear bond strength and extension length was shown in indirect bonding method(p<0.05).
Bicuspid ; Orthodontic Retainers ; Orthodontic Wires

No abstract available.
Hot Temperature* ; Orthodontic Wires*

Humans ; Orthodontic Appliance Design ; Orthodontic Wires

The purpose of this study was to evaluate the torque effect of orthodontic wires. Ten types of orthodontic wires (five types of materials, two types of cross-sectional dimensions) were selected. Each group of wire type was constituted with five specimens. These specimens were tested on the universal testing machine(Instron) with specially-designed jig. The torque-twist curve of each wire was obtained and the results were analyzed statistically. The results were as follows: 1. 0.017" X 0.025" wire showed more torque effect than 0.016" X 0.022" wire at the same twist. 2. Torque effect was the greatest in stainless steel and the least in Nitinol. 3. The maximum amount of torque was the greatest in heat-treated Blue Elgiloy and the least in Nitinol.
Orthodontic Wires* ; Stainless Steel ; Torque*

OBJECTIVE: We evaluated the detachment force, amount of deformation, fracture mode, and pull-out force of 3 different wires used for bonded lingual retainer fabrication. METHODS: We tested 0.0215-inch five-stranded wire (PentaOne, Masel; group I), 0.016 x 0.022-inch dead-soft eight-braided wire (Bond-A-Braid, Reliance; group II), and 0.0195-inch dead-soft coaxial wire (Respond, Ormco; group III). To test detachment force, deformation, and fracture mode, we embedded 94 lower incisor teeth in acrylic blocks in pairs. Retainer wires were bonded to the teeth and vertically directed force was applied to the wire. To test pull-out force, wires were embedded in composite that was placed in a hole at the center of an acrylic block. Tensile force was applied along the long axis of the wire. RESULTS: Detachment force and mode of fracture were not different between groups. Deformation was significantly higher in groups II and III than in group I (p < 0.001). Mean pull-out force was significantly higher for group I compared to groups II and III (p < 0.001). CONCLUSIONS: Detachment force and fracture mode were similar for all wires, but greater deformations were seen in dead-soft wires. Wire pull-out force was significantly higher for five-stranded coaxial wire than for the other wires tested. Five-stranded coaxial wires are suggested for use in bonded lingual retainers.
Axis, Cervical Vertebra ; Incisor ; Orthodontic Wires ; Tooth

HX straight-wire appliance (HX-SWA) is designed and adjusted by doctors of Orthodontic Department, West China College of Stomatology, Sichuan University. It is a set of appliance that is constructed according to normal occlusion features of the Chinese people, including the prescription of tip, torque, in/out, counter-tip, counter-rotation and overcorrection in brackets and buccal tubes. Some ingredients of the appliance are different from that of the most popular Roth straight-wire appliance in the world wide. Over a period of the last 10 years, doctors in our hospital kept on summarizing treatment experience with HX-SWA, which will help more doctors promote practice and results in orthodontic clinic.
Dental Occlusion ; Humans ; Orthodontic Wires ; Rotation

OBJECTIVETo study the properties of orthodontic rectangular arch wires in torsion.

METHODSBy using the torsion measurement apparatus, torsion moments and angles of four kinds of orthodontic wires (0.46 mm x 0.63 mm and 0.48 mm x 0.63 mm stainless steel wires, and the same size nickel-titanium wires) were tested respectively in a 0.56 mm-slot first maxillary incisor bracket. According to the torsion moments and angles, scatter graphs were drawn to fit the load-deflection curves of four kinds of wires and their linear equations were calculated. According to the equations, the torsion stiffness and the play angles of the wires at 20 N mm correspondingly were calculated.

RESULTSThe torsion stiffness of four kinds of wires were 4.909, 6.417, 1.325 and 1.363 N mn/degrees, the torsion angles of different wires were 19.14 degrees, 15.33 degrees, 36.83 degrees and 35.07 degrees at 20 N mm respectively.

CONCLUSIONThe torsion stiffness of stainless steel wires was bigger than that of the same cross-section dimensional nickel-titanium wires. The difference of torsion stiffness between two dimensional nickel-titanium wires is smaller, while the difference of torsion stiffness between two stainless steel wires is larger.

OBJECTIVETo investigate the difference between straight wire appliance and edgewise appliance treatment outcome.

METHODS80 cases finished with two-arch straight wire or edgewise appliance between 1994 and 2001 were selected. The PAR index on pre- and post-treatment dental casts and PAR score was recorded respectively. According to the same pre-treatment PAR score and extraction pattern, the samples were divided into two groups, straight wire group and edgewise group, and each group had 40 cases. The data were analyzed statistically.

RESULTSEstimated with the post-treatment PAR score of posterior teeth alignment, the treatment with straight wire appliance was lower than that with edgewise appliance (P < 0.01). There was no statistical difference in other recorded PAR score between two groups. For the mean treatment duration, straight wire appliance (3.95 months) was shorter than edgewise appliance.

CONCLUSIONAs for the posterior teeth alignment, the straight wire appliance was more accurate, and the straight wire appliance was more efficient than edgewise appliance.

This study was conducted to evaluate the effects of loop formation and heat treatment upon the elastic properties of orthodontic wires. The specimens selected were 016", .018", 016 x 022", and .018 x 022" sized stainless steel (standard) and cobalt-chromium-nickel wires, and were divided into 7 groups as, 1. straight non-heat treated 2. U looped non-heat treated 3. L looped non-heat treated 4. Circle looped non-heat treated 5. U looped heat treated 6. L looped heat treated 7. Circle looped heat treated Heat treatment was performed in Big Jane furnace at 850' F for 3 minutes. The elastic limit and the elastic range of each specimen were determined by bending test, and load deflection rate was computed from those values. The findings were as follows, 1. The formation of loop resulted in increased load-deflection rate for both stainless steel and cobalt-chromium-nickel wires. 2. The heat treated group showed higher load-deflection rate than non-heat treated group, which was more apparent in cobalt-chromiumnickel wire than in stainless steel wire. 3. L loop had the highest Ioad-deflection rate among 3 types of loops, followed by U loop and circle loop. 4. The specimens with greater diameter displayed the more increase in load-deflection rate by looping and heat treatment.
Hot Temperature* ; Orthodontic Wires ; Stainless Steel