Measurement Analysis of the Frictional Resistance Between Tandem Archwire and Different Self-ligating Brackets / 昆明医科大学学报

Objective To measure the dynamic and static frictional resistances between different self-ligating orthodontic brackets and different combination of tandem archwires.Methods On standard model the upper right quadrant Damon Q self-ligating brackets was pasted as team A,3M Smart clip self-ligating brackets as team B and Forestadent Quick 3.0 self-ligating brackets as team C respectively.Nickel-titanium archwires of 0.012 inch and 0.016 inch and two nickel-titanium archwires of 0.014 inch were applied to simulate sliding in the brackets and measure the friction changes in brackets and archwires,so as to explore the frictional resistance between different combination of the tandem archwires and different self-ligating brackets.Results When using the combination of two 0.014-inch nickel-titanium tandem archwires,the static frictional resistances was significantly different (P＜ 0.05):team A ＜team B ＜team C while the kinetic frictional resistance was also significantly different (P＜0.05):team A ＜team B ＜team C,When using the combination of 0.012-inch and 0.016-inch nickel-titanium tandem archwires,the static frictional resistances was significantly different (P＜0.05):team A＜team B＜team C,while the kinetic frictional resistance was also significantly different (P＜0.05):team A＜team B＜team C.Gonclusion There are different frictional resistance in different kind of self-ligating brackets and different combination of the tandem archwires.The combination of two 0.014-inch nickel-titanium tandem archwire applied to Forestadent Quick 3.0 self-ligating brackets has the biggest frictional resistance while the combination of 0.012-inch and 0.016-inch nickel-titanium tandem archwire applied to the Damon Q self-ligating brackets has the lowest frictional resistance,which enables the teeth to move at the fastest speed and facilitates the following use of the edgewires.

Comparative evaluation of frictional characteristics of coated low friction ligatures - Super Slick Ties™ with conventional uncoated ligatures.

Background: Elastomeric ligatures have constituted a versatile method of securing the archwire to bracket slot, though self-ligating brackets have been a recent innovation. Coating elastomeric ligatures with a hydrophobic polymeric substance has been suggested as a methodology in reducing friction at the archwire-bracket interface and in repelling salivary adherends. A new polymeric coated ligature tie - Super Slick Ties™ (SST), manufactured using Metafasix technology, has been marketed by TP laboratories for potential reduction in treatment time. Aim: The basic in vitro design is to compare the frictional characteristics of the coated ligatures with those of uncoated ligatures in four different archwires, namely, stainless steel, NiTi, TMA, and Timolium. Materials and Methods: Four archwires used are stainless steel archwires, TMA archwires, Timolium, NiTi archwires, and two types of elastomeric ligatures (the coated and uncoated ligatures) were used. The wires used were of 0.019 × 0.025 dimension. The evaluation of friction between the brackets and the archwire was carried out as per the test protocol described by Tidy. The values for kinetic friction were obtained and tabulated. Mean and standard deviation were calculated. Paired Student's "t" test was performed to analyze the significance of difference between means. Results: The results indicate a significant difference in friction produced when coated and conventional uncoated ligatures were used. Conclusions: SST produced lower levels of friction (11%) for all archwire materials when compared to conventional uncoated ligatures (Dispense-A-Stix) and both conventional uncoated ligatures and coated ligatures gave a rank order of coefficient of kinetic friction (μkf) among archwires, with stainless steel archwires exhibiting the least and TMA TM showing the highest.

Changes in frictional resistance between stainless steel bracket and various orthodontic wires according to a change in moment / 대한치과교정학회지

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.

Friction of calcium phosphate brackets to stainless steel wire / 대한치과교정학회지

OBJECTIVE: Esthetic brackets which resemble the color of natural teeth have been widely used. But the frictional resistance of ceramic brackets, a typical esthetic bracket, is greater than that of metal brackets. The purpose of this study was to measure the frictional resistance of the new calcium phosphate brackets (CPB) which were recently developed and to evaluate its clinical usability by comparing the frictional differences of CPB with metal brackets and metal slot inserted ceramic brackets. METHODS: Experimental groups were CPB (Hyaline II, Tomy, Tokyo, Japan), metal bracket (Kosaka, Tomy, Tokyo, Japan) and metal slot inserted ceramic bracket (Clarity, 3M Unitek, Monrovia, CA, USA). All of the brackets had 0.022-inch slot sizes. The brackets were tested with 0.019 x 0.025 inch stainless steel wire (3M Unitek, Monrovia, CA, USA). A biologic model was used to simulate the situation which would occur during orthodontic treatment with fixed appliances. Retraction force was applied at a speed of 5 mm/min for 30 seconds. The frictional resistance was measured on a universal testing machine (Instron 4467, Instron, Norwood, MA, USA). RESULTS: CPB showed significantly higher friction than metal brackets (p < 0.05) and lower friction than metal slot inserted ceramic brackets (p < 0.01). CONCLUSIONS: CPB can be considered to be a useful orthodontic esthetic bracket with respect to frictional resistance, as its friction is remarkably lower than that of metal slot inserted ceramic brackets.

Frictional resistance of different ceramic brackets and their relationship to the second order angulation between bracket slot and wire / 대한치과교정학회지

Although ceramic brackets have been used widely for improved esthetics during treatment, ceramic brackets have some inherent problems; brittleness, attrition of the opposing teeth and high frictional resistance. This study was performed to understand the frictional resistance of the ceramic brackets, as well as to be a helpful reference for finding the solutions to the problem of frictional resistance. Three different kinds of brackets were used; metal bracket, polycrystalline ceramic brackets with a metal slot to reduce the high frictional resistance and monocrystalline ceramic brackets. The brackets were tested with a .019 x .025 stainless steel wire with a second order angulation of 0 degrees and 10 degrees, and the static and kinetic frictional forces were measured on the universal testing machine. The results of this study showed that the ceramic brackets, especially the monocrystalline ceramic bracket without a metal slot, generated higher frictional resistance than the metal bracket, and the frictional resistance was increased as the angulation between the bracket slot and the wire increased. Therefore, the development of the ceramic bracket with reduced frictional resistance and the prevention of excessive crown tipping during orthodontic treatment will lead to the simultaneous attainment of more efficient and improved esthetic treatment goals.

An experimental study on dynamic frictional resistance between brackets and archwires under the wet condition / 实用口腔医学杂志

Objective:To study the dynamic frictional resistance in the buccal segment between preadjusted brackets coupled with different archwires,at different times under artificial saliva condition.Methods: The dynamic friction of different combinations of 4 kinds of preadjusted brackets and 4 archwires were tested simulating archwires sliding in the buccal segments at 4 different times(0,15,30,45 d)under artificial saliva condition by using Instron universal testing machine.Results: The dynamic frictional resistance of combinations of 3M MBT bracket and all archwires were the smallest.The combinations of 0.46 mm inch stainless steel round wire and all brackets produced significantly lower dynamic frictional resistance than that of other archwires.The 0.48 mm?0.64 mm inch stainless steel rectangular wire produced the highest dynamic frictional resistance combined with all preadjusted brackets.The dynamic frictional resistance of combinations of archwires and brackets were highest at the 15th day and smallest at the 30th day under artificial saliva condition.Conclusion: 0.46 mm stainless steel round wire produces the smallest dynamic frictional resistance combined with all preadjusted brackets.3M MBT brackets are more favorable to sliding mechanics compared with other brackets.As for time,the lowest dynamic frictional resistance exhibits at the 30th day under artificial saliva condition.

An experimental study of dynamic frictional resistance between orthodontic bracket and arch wire / 대한치과교정학회지

This investigation was designed to determine the effects of wire size, bracket width and the number of bracket on bracket-wire dynamic frictional resistance during simulating arch wire-guided tooth movement in vitro. For simulation of an arch wire-guided tooth movement, we simulated tooth, periodontal ligament and cancellous bone. Maxillary premolar and 1st molar were simulated as real sized resin teeth, the simulated resin teeth which its root was coated by polyether impression material which its elastic modulus is similar to periodontal ligament were embedded in steel housing with inlay wax which its elastic modulus is similar to cancellous bone. Stainless steel wires in four wire size (0.016, 0.018, 0.016 x 0.022, 0.019 x 0.025 inch) were examined with respect to three (stainless steel) bracket widths (2.4, 3.0, 4.3mm) and the number of medium bracket(one, two, three) included in the experimental assembly under dry condition. The wires were ligated into the brackets with elastomeric module. The results were as follows : 1. In all the brackets, frictional resistance increased with increase in wire size. But, statistically similar levels of frictional resistance were observed between 0.018 inch and 0.016 x 0.022 inch wires in narrow bracket and also between 0.016 inch and 0.018 inch wire in wide backet. 2. The frictional forces produced by 0.016 inch wire were statistically similar levels in all the brackets. In 0.018 inch round wire, wide bracket was associated with lower amounts of friction than both narrow and medium brackets. In 0.016 x 0.022, 0.019 x 0.025 inch rectangular wire, wide bracket produced larger friction than both narrow and medium brackets. In all the wires, narrow and medium bracket demonstrated no statistical difference in levels of frictional resistance. 3. Frictional resistance increased with increase in number of medium bracket. 0.016 inch round wire demonstrated the greatest increment in frictional resistance, followed by 0.019 x 0.025, 0.016 x 0.022 inch rectangular wire which were similar level in increment of frictional resistance, 0.018 inch wire demonstrated the least increment. The increments of frictional resistance were not constantly direct proportion to number of bracket.

The frictional resistance of tin ion-plated Co-Cr orthodontic wire / 대한치과교정학회지

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.

Comparison of the frictional resistance between non-ion plated and Tin ion plated to the orthodontic appliance / 대한치과교정학회지

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.