The purpose of this study was to evaluate and compare frictional forces generated between orthodontic brackets and arch wires. Independent variables were chosen for study: arch wire size and shape, arch wire material, bracket width, and second-order angulation between bracket and arch wire. Kinetic frictional forces of stainless steel (0.014", 0.016", 0.018", 0.016" x 0.022", 0.018" x 0.022"), beta-titanium (0.016" x 0.022") arch wires were measured on wide and junior edgewise twin brackets (0.018" x 0.022" slot). Instron was used to pull arch wires while 0degrees, 3degrees, 6, or 9degrees angulation between and wire and bracket was given. The results were as follows: 1. The frictional force of beta-titanium wire was larger than that of stainless steel wire. 2. The frictional force was generally increased as the size of wire is increased. 3. The frictional force of rectangular wire was larger than that of round wire. 4. As second order angulation was increased, the frictional force was also increased. 5. The frictional force was larger on a wide bracket than on a junior bracket.
Friction* ; Humans ; Orthodontic Brackets* ; Stainless Steel ; Tooth*

To estimate the possibility in the application of TiN ion-plating to the orthodontic appliance, this study investigated frictional force and frictional coefficient between non-ionplated and TiN ion-plated to the orthodontic appliance. The obtained results were as follows: 1. For each group, the frictional force between metal bracket and arch wire in the wet condition was exhibited lower than that in the dry condition. 2. In the dry condition, the frictional force was lowest with fourth group, and it increased in the order of the 3rd, 1st, and 2nd group. Same situation happened in the wet condition. 3. Experimental results using ceramic & plastic bracket showed that group B was lower than group A, and group D was similar to group C. 4. The surface texture after experiment showed that the scratch due to a friction with bracket was observed in an arch wire of dry contition. Also the surface of bracket was rougher than before. 5. We observed that a specimen surface processed with the TiN ion plating was smoother than that of without the TiN ion plating. 6. The surface texture of a metal bracket and an arch wire in the wet condition was observed smoother than that in the dry condition. 7. In the dry condition, the friction coefficient of each specimen was very similar to each other, but in the wet condition, the friction coefficient of specimen processed with the TiN ion plating showed lower values.
Ceramics ; Friction* ; Orthodontic Appliances* ; Plastics ; Tin*

The effectiveness of TiN ion-plating was examined with TiN ion-plated Co-Cr wires(016", 016"X.022") on three different types of bracket(TiN ion-plated metal bracket, ceramic bracket and plastic bracket). Maximum static frictional forces and characteristic curves obtained from the frictional characteristic graph, were compared and surface roughness of wires and bracket slots before and after friction experiment was observed by SEM. The obtained results were as follows. · The frictional forces of TiN ion-plated wires were significantly lower than those of non ion-plated wires(P<0.O5 ).· On the effect of wire shape, the frictional forces of round wires were significantly lower than those of rectangular wires(P<0.05). · As the result of the SEM observation on the wires and bracket slots after the friction experiment, the surface of non ion-plated wires was rougher than that of TiN ion-plated ones. · The difference between the static frictional forces and the kinetic frictional forces was not significant in case of the TiN ion-plated round wires, but the static frictional forces were a little higher than the kinetic frictional forces in the TiN ion-plated rectangular wires. · The static frictional forces were much higher than the kinetic frictional forces in the case of non ion-plated wires.
Ceramics ; Friction* ; Orthodontic Wires* ; Plastics ; Tin*

As increasing number of adult patients, the esthetic orthodontic appliances are needed. They are tooth-colored or translucent ceramic and resin brackets. Although ceramic and resin bracket have good esthetics, there are some disadvantage such as frictions. Recently, metal-reinforced resin bracket(MRRB) were introduced. The purpose of this study is to find frictional force of MRRB, ceramic bracket and resin brackets. There is few study in frictional force about metal reinforced resin bracket(MRRB). This study used 4 orthodontic wire(.016S-S, .016TMA(R), .017X.025 TMA(R))and 5 brackets(one metal bracket, one ceramic bracket, one resin bracket, two MRRB). the following result is obtained using metal bracket(Ormco.Co., U.S.A), ceramic brackets(Crystalline(R), resin bracket(Clear Medium Siamase(R)). Following conclusions are obtained. 1. Ceramic and resin bracket have significantly more frictional forces than metal reinforced resin bracket and metal bracket. 2. There is no significant difference in frictional force according to the slot types of metal-reinforced resin brackets. 3. There is no significant difference in frictional force between metal reinforced resin bracket and metal bracket. 4. Frictional force is decreased in S-S wire than TMA wire.
Adult ; Ceramics ; Esthetics ; Friction* ; Humans ; Orthodontic Appliances

The object of this study was to evaluate how friction that occurs during the sliding movement of an orthodontic archwire through orthodontic brackets is differently affected by variant designs and ingredients of brackets and archwires and bracket-archwire angles. In order to simulate the situations which could occur during orthodontic treatment with fixed appliances, 4 types of brackets (Gemini(R), a stainless steel twin bracket; Mini Uni-Twin(R), a stainless steel bracket with a single bracket design and narrow mesio-distal width; Clarity(R), a metal-reinforced ceramic bracket; Transcend(R), a ceramic bracket) and 3 types of orthodontic archwires (0.016", 0.016 x 0.022" stainless steel, 0.016" Nitinol) were used and the bracket-archwire angles were controlled as 0 degrees, 3 degrees, 6 degrees, and 9 degrees, Gemini(R) significantly showed the lowest static and kinetic frictions (P < 0.001). Clarity showed the highest static and kinetic frictions with a bracket-archwire angle of 0 degrees, and Transcend at 6 degrees and 9 degrees (P < 0.001). An 0.016 x 0.022" stainless steel rectangular archwire significantly showed the highest static and kinetic frictions (P < 0.01). The lowest static and kinetic frictions were observed when the bracket-archwire angles were 0 degrees and 3 degrees with 0.016" stainless steel round archwires (P < 0.01), and 6 degrees and 9 degrees with 0.016 Nitinol (P < 0.001). The static and kinetic frictions were increased as the bracket-archwire angles were increased (P < 0.001).
Ceramics ; Friction* ; Humans ; Orthodontic Brackets* ; Stainless Steel

OBJECTIVETo measure the frictions between FAS bracket and stainless steel wire under different two conditions, and compare two traditional self-ligating brackets.

METHODSFAS bracket was a new-style self-ligating bracket with a friction adjusting system (FAS) to adjust the friction as the wires slide in the bracket. Firstly, FAS bracket 20 times of original size was made, then the frictions were measured respectively made by the steel round wires of diameters 8.128 0 mm or the steel square wires in size of 9.1440 mm x 12.7000 mm. It was divided into two adjusting states, and used the same method to measure Damon III and SPEED bracket in 20 times of original size.

RESULTSWith the shim entirely drew in, all the frictions of the arch wire had no significant difference with the Damon III. When 8.1280 mm stainless steel round wire was used, SPEED bracket had no significant difference with FAS. When 9.1440 mm x 12.7000 mm square wire was used, they had significant difference (P < 0.05). On turning half a circle, all the frictions of the arch wire had significant difference with two tradition bracket (P < 0.01).

CONCLUSIONThe new-style FAS bracket can adjust the friction efficiently. Under no pressure state, the friction force is similar to Damon III. Under pressure state, FAS bracket locks the wires, and provides the sliding of wires.

Z2 appliance is the pre-adjusted appliance designed for Chinese orthodontic patients. The prescription of the appliance is based on Chinese normal occlusion, which is much different from the West in the first and the second orders as well as the third one. The appliance routinely includes 20 brackets and 8 molar buccal tubers with 3 standard arch forms. Clinically, continued light force is used in whole treatment. The side-effects such as forward tipping of incisors, bite deepening and loss of molar anchorage are reduced further due to fewer tips built into the anterior brackets as well as lower friction elastometric modules used during aligning and leveling. In condition of arch are leveled completely, 0.48 mm x 0.64 mm stainless steel archwire with 1.47 N retraction force is the best combination for sliding mechanics, which is proved by 3D nonlinear finite element study. Self drilling micro-screw is used for maximum anchorage. In finishing stage 0.53 mm x 0.64 mm NT arch wire is added in order to get full torque expressing. The research of Chinese pre-adjusted appliance has been lasted for more than 10 years in the department and clinical studies on Z2 appliance show that with minimal wire bending, treatment is more efficient and result is high quality and more consistent for Chinese orthodontic patients.
Dental Occlusion ; Friction ; Humans ; Incisor ; Molar ; Orthodontic Appliance Design ; Orthodontic Brackets ; Orthodontic Wires ; Stainless Steel

OBJECTIVE: This study aimed to compare the frictional force (FR) in self-ligating brackets among different bracket-archwire angles, bracket materials, and archwire types. METHODS: Passive and active metal self-ligating brackets and active ceramic self-ligating brackets were included as experimental groups, while conventional twin metal brackets served as a control group. All brackets were maxillary premolar brackets with 0.022 inch [in] slots and a -7degrees torque. The orthodontic wires used included 0.018 round and 0.019 x 0.025 in rectangular stainless steel wires. The FR was measured at 0degrees, 5degrees, and 10degrees angulations as the wire was drawn through the bracket slots after attaching brackets from each group to the universal testing machine. Static and kinetic FRs were also measured. RESULTS: The passive self-ligating brackets generated a lower FR than all the other brackets. Static and kinetic FRs generally increased with an increase in the bracket-archwire angulation, and the rectangular wire caused significantly higher static and kinetic FRs than the round wire (p < 0.001). The metal passive self-ligating brackets exhibited the lowest static FR at the 0degrees angulation and a lower increase in static and kinetic FRs with an increase in bracket-archwire angulation than the other brackets, while the conventional twin brackets showed a greater increase than all three experimental brackets. CONCLUSIONS: The passive self-ligating brackets showed the lowest FR in this study. Self-ligating brackets can generate varying FRs in vitro according to the wire size, surface characteristics, and bracket-archwire angulation.
Bicuspid ; Ceramics ; Friction* ; Humans ; Orthodontic Wires ; Stainless Steel ; Torque

OBJECTIVE: The coefficients of friction (COFs) of aesthetic ceramic and stainless steel brackets used in conjunction with stainless steel archwires were investigated using a modified linear tribometer and special computer software, and the effects of the bracket slot size (0.018 inches [in] or 0.022 in) and materials (ceramic or metal) on the COF were determined. METHODS: Four types of ceramic (one with a stainless steel slot) and one conventional stainless steel bracket were tested with two types of archwire sizes: a 0.017 x 0.025-in wire in the 0.018-in slots and a 0.019 x 0.025-in wire in the 0.022-in slot brackets. For pairwise comparisons between the 0.018-in and 0.022-in slot sizes in the same bracket, an independent sample t-test was used. One-way and two-way analysis of variance (ANOVA) and Tukey's post-hoc test at the 95% confidence level (alpha = 0.05) were also used for statistical analyses. RESULTS: There were significant differences between the 0.022-in and 0.018-in slot sizes for the same brand of bracket. ANOVA also showed that both slot size and bracket slot material had significant effects on COF values (p < 0.001). The ceramic bracket with a 0.022-in stainless steel slot showed the lowest mean COF (micro = 0.18), followed by the conventional stainless steel bracket with a 0.022-in slot (micro = 0.21). The monocrystalline alumina ceramic bracket with a 0.018-in slot had the highest COF (micro = 0.85). CONCLUSIONS: Brackets with stainless steel slots exhibit lower COFs than ceramic slot brackets. All brackets show lower COFs as the slot size increases.
Aluminum Oxide ; Ceramics ; Friction* ; Orthodontic Brackets* ; Stainless Steel

OBJECTIVE: The purpose of this study was to compare changes in frictional resistance between the bracket and wire under dry and wet conditions according to a change in moment. METHODS: A stainless steel bracket of 0.022" x 0.028" slot, and 0.019" x 0.025" stainless steel, beta-titanium, and nickel-titanium wires were used. A 10 mm length lever was attached to the test (sliding) brackets to generate a moment. The experimental model was designed to allow tipping until contacts were established between the wire and the mesiodistal edges of the bracket slot. The moment was generated by suspending a 100 g or 200 g weight on the end of the lever. The moments applied were 1000 g.mm (100 g x 10 mm) and 2000 g.mm (200 g x 10 mm). The test brackets were ligated with elastomeric ligature for a constant ligation force and the fixed brackets were ligated with stainless steel ligature. Brackets were moved along the wire by means of an universal testing machine, and maximum frictional resistances were recorded. RESULTS: Stainless steel wire showed least frictional resistance and there was no significant difference between beta-titanium and nickel-titanium except at 2000 g.mm moment in wet conditions. Frictional resistance of all wires increased as the moment increased from 1000 g.mm to 2000 g.mm. Under wet conditions, the frictional resistance of stainless steel wires increased in both 1000 g.mm and 2000 g.mm moment conditions, but frictional resistance of nickel-titanium and beta-titanium increased only in 2000 g.mm conditions. CONCLUSION: These results indicated that various conditions influence on frictional resistance. Therefore, laboratory studies of frictional resistance should simulate clinical situation.
Elastomers ; Friction* ; Ligation ; Models, Theoretical ; Orthodontic Wires* ; Stainless Steel*