Kinetic Frictional Resistance Research Articles

Dimensional accuracy, mechanical property, and optical stability of zirconia orthodontic bracket according to yttria proportions

This in vitro study evaluated comprehensively the performances of zirconia brackets with varying yttria proportions in manufacturing advanced orthodontic brackets. Three experimental groups of zirconia brackets were fabricated using yttria-stabilized zirconia (YSZ) materials with different yttria proportions—3 mol% yttria (3Y-YSZ), 4 mol% yttria (4Y-YSZ), and 5 mol% yttria (5Y-YSZ) (Tosoh Ceramic, Japan). A polycrystalline alumina ceramic bracket (3M™ Clarity™ Advanced, MBT 0.022-in. slot) was employed as the control group. Morphological properties, including slot surface structure and dimensions, were examined using scanning electron microscopy and surface profiler analysis. Manufacturing accuracy was assessed with root mean square calculations of trueness and precision. Mechanical properties were tested, encompassing static and kinetic frictional resistance (FR) and fracture strength. Optical stability was evaluated through 20,000 cycles of thermocycling and a 7-day immersion in various coloring agents. Within the limitations of this study, zirconia brackets containing 3 to 5 mol% YSZ presented enhanced reliability in terms of dimensional accuracy and demonstrated favorable optical stability. Notably, owing to its advantageous mechanical properties, the 3Y-YSZ variant showed remarkable potential as an advanced material for fabricating orthodontic brackets.

Evaluation of the effect of different toothpastes on the frictional resistance of aesthetic archwires: an in vitro study

there has been a trend for using aesthetic orthodontic treatment by many patients recently. The aim of this study was to evaluate the brushing effect of three brands of toothpaste on the frictional resistance of two brands of aesthetic archwires (in wet conditions). in this study, two brands of fully coated aesthetic archwires, Teflon-coated and Epoxy-coated archwires, were utilized in the study. Forty segments from the straight ends of each archwire were cut (total of 80 wires), inserted into ceramic brackets and ligated with the conventional figure "O" elastomeric ligatures (bonded on CNC blocks). Every ten pieces for each type of aesthetic archwire were brushed for one minute daily for thirty days with three types of toothpaste (Ortho. Kin, GUMOrtho and LACALUT White & Repair) and distilled water (except ten pieces for each type of aesthetic archwire were brushed only with distilled water and without toothpaste). These CNC blocks were tested using an Instron Tinius Olsen machine with distilled water. The tests used for statistical analysis were an Independent t-test and an ANOVA test at a 0.05 level of significance. The study showed no significant difference in static and kinetic frictional resistance between the coated archwire and the kinds of toothpaste. The orthodontists can use either Epoxy or Teflon-coated archwires for patients undergoing orthodontic treatment (working stage) who are using either type of toothpaste (Ortho. Kin, GUMOrtho or LACALUT White & Repair) for maintenance of oral hygiene. Keywords: Aesthetic archwires, Friction, Toothpaste

The Effect of Different Extrinsic Lubricates on Frictional Resistance Between the Orthodontic Bracket and Archwire: an in vitro study

Aim of the study: The purpose of this research was to investigate how the static and kinetic friction between the orthodontic bracket and archwire will be affected by artificial saliva (AS), oil-containing mouthwash (TTO), and olive oil (OO).
 Materials and methods: On an Instron universal testing machine with a load cell of 10N and a speed of 2 mm/min. Thirty premolar brackets with 0.019 x 0.025inch stainless steel archwires were assessed. The samples were allocated into three groups randomly. Ten test units were immersed in artificial saliva AS (control group), Tea tree oil mouthwash TTO, and olive oil OO (study groups) for 90 minutes at room temperature. Each test unit is evaluated once only. Statistical analysis used was the ANOVA and Post Hoc LSD tests for parametric tests, the Kruskal-Wallis test, and the Pairwise Comparison test for non-parametric tests.
 Results: The samples immersed in olive oil significantly showed increased static and kinetic frictional resistance (p= 0.009 and 0.001, respectively), and the TTO showed the least static and kinetic frictional resistance.
 Conclusion: The 90-minute immersion in oil-containing mouthwash reduced static and kinetic frictional resistance between the orthodontic brackets and archwires, while olive oil (OO) significantly increased them. Based on these findings, oil-containing mouthwash can be prescribed as an excellent prophylactic agent for orthodontic patients. However, the OO is not recommended during the sliding mechanics.

A novel customized ceramic bracket for esthetic orthodontics: in vitro study

BackgroundThis study aims to develop a novel process to establish a standardized manufacturing technique of customized esthetic ceramic bracket system (CCB) which could be endowed with individual color and shape to satisfy patients’ individual demands. Material characteristics and mechanical parameters of CCB were evaluated.Subjects and methodsCCB virtual models were designed individually according to patient’s teeth morphology and clinical demands. 3D printing technology, lost-wax technology, and selected glass-ceramic ingots were employed to fabricate CCB. Scanning electron microscopy (SEM) analyses were performed to characterize the surface morphology of CCB and commercially available brackets (Clarity Advanced; Crystalline VII; Inspire ICE; Damon Q). Static and kinetic frictional resistance (FR), shear bond strength (SBS) and adhesive remnant index (ARI) scores were recorded. One-way analyses of variance (ANOVA) and post-hoc Tukey’s HSD multiple tests were used for statistical analyses.ResultsMulti-color and multi-transparency raw materials facilitated CCB with a wide range of color options and controllable optical properties to satisfy different esthetic demands of individual orthodontic patients. CCB presented same level of FR as commercially available ceramic brackets did. No significant differences (P ≥ 0.05) of SBS were observed among CCB-ES (treated silane), Clarity Advanced and Crystalline VII groups, and CCB-E (no silane) attained the highest ARI mean score 3. In the preliminary clinical trial, CCB presented excellent color-matching and shape-matching appearances similar to natural teeth, which made it highly invisible from social intercourse distance.ConclusionsCCB were demonstrated to be an applicable labial orthodontic bracket system with optimized esthetics and biomechanics. We envision that it would be an ideal alternative for patients who pursue esthetic orthodontic treatment but were not likely to take lingual appliances or clear aligners.

The effect of simulated erosive conditions on the frictional behavior of different orthodontic bracket-wire combinations.

Frictional resistance is an important parameter in orthodontics that influences the effectiveness of archwire-guided tooth movement. Since the consumption of dietary acids has increased considerably over the last 2 decades, there is a rationale for investigating the process of degradation of orthodontic materials in an acidic environment and its effect on clinical efficiency. The aim of this study was to evaluate the effect of simulated erosive conditions on the frictional behavior between the brackets of 3 different materials and 3 different wire alloys. Three types of twin orthodontic brackets (stainless steel (SS), monocrystalline ceramic and titanium) and 3 types of archwires of the same dimension (SS, nickel-titanium (Ni-Ti) and beta-titanium (titanium-molybdenum alloy - TMA) were tested in 9 different combinations under simulated erosive and non-erosive conditions (18 groups, n = 10). Bracket-wire specimens in the erosivecondition groups were subjected to a pH cycling regimen with 1% citric acid and artificial saliva for 5 consecutive days. Bracket-wire specimens from the non-erosive-condition groups were incubated only in artificial saliva for 5 days. Static and kinetic friction were determined by measuring the force needed to move the wire through the bracket. A three-way analysis of variance and pairwise comparisons with the Student-Newman-Keuls test were performed. Irrespective of the conditions, SS brackets with SS wire demonstrated significantly lower mean static and kinetic frictional resistance than other bracket-wire combinations (p < 0.01). Ceramic and titanium brackets generated high frictional forces with all 3 types of wire tested. Erosive conditions did not significantly influence static and kinetic frictional resistance in all bracket-wire groups. Erosive conditions do not affect the frictional behavior of SS, Ni-Ti and TMA orthodontic archwires at a clinically significant level.

A Comparative Study of Static and Kinetic Frictional Resistance during the Sliding of Arch Wires through Orthodontic Brackets, using Different Methods of Ligation, in the Dry State

Frictional resistance is crucial between arch wires and brackets, sometimes benefic and in other clinical situations undesirable, making difficult to apply orthodontic forces efficiently. There are many variables that influence frictional resistance and the method of ligation is one of the most important. The objective of this study was to compare static and kinetic frictional resistance during the sliding of 0.016” and 0.016” × 0.022” SS arch wires (upper and lower) through orthodontic brackets, using different methods of ligation (elastomeric ties, low friction elastomeric ties, stainless steel ligature, active and passive self-ligating brackets). It was developed an original methodology to evaluate frictional resistance to sliding with different methods of ligation. The results showed that the method of ligation that generated the highest static and kinetic frictional resistance values was elastomeric ties, followed by low friction elastomeric ties>metallic ligature> and at last self-ligating brackets for all arch wires.

A Comparative Study of Static and Kinetic Frictional Resistance during the Sliding of Arch Wires through Orthodontic Brackets, using Different Methods of Ligation, in the Dry State

A Comparative Study of Static and Kinetic Frictional Resistance during the Sliding of Arch Wires through Orthodontic Brackets, using Different Methods of Ligation, in the Dry State

Comparative Evaluation of Frictional forces between different Archwire-bracket Combinations

Introduction: During sliding mechanics, frictional resistance is an important counterforce to orthodontic tooth movement; whichmust be controlled to allow application of light continuous forces.Objective: To investigate static and kinetic frictional resistance between three orthodontic brackets: ceramic, self-ligating, andstainless steel, and three 0.019×0.025” archwires: stainless steel, nickel-titanium, titanium-molybdenum.Materials &amp; Method: The in vitro study compared the effects of stainless steel, nickel-titanium, and beta-titanium archwires onfrictional forces of three orthodontic bracket systems: ceramic, self-ligating, and stainless steel brackets. All brackets had 0.022”slots, and the wires were 0.019×0.025”. Friction was evaluated in a simulated half-arch fixed appliance on a testing machine. Thestatic and kinetic friction data were analyzed with 1-way analysis of variance (ANOVA) and post-hoc Duncan multiple rangetest.Result: Self-ligating (Damon) brackets generated significantly lower static and kinetic frictional forces than stainless steel (Gemini)and ceramic brackets (Clarity). Among the archwire materials, Beta-titanium showed the maximum amount of frictional forceand stainless steel archwires had the lowest frictional force.Conclusion: The static and kinetic frictional force for stainless steel bracket was lowest in every combination of wire.

Mechanical and topographic evaluation of esthetic brackets and its relation to frictional resistance

Introduction: The purpose of this in-vitro study was to evaluate the frictional characteristics of conventional ceramic versus metal insert ceramic brackets in combination with stainless steel and Teflon-coated stainless steel archwires. Materials and Methods: Twenty brackets each, of ceramic and metal insert ceramic Maxillary canine preadjusted edgewise brackets 0.022 × 0.028 in slot) and 20 archwires, each of stainless steel and Teflon-coated stainless steel (0.019 × 0.025 in) were tested for frictional resistance. Friction was evaluated in a simulated Tidy's design apparatus on universal testing machine. The kinetic friction data were analyzed using Student's 't' test. The effects of surface characteristics on frictional resistance were qualitatively assessed using scanning electron microscope. Results: Metal insert ceramic brackets generated significantly lower kinetic frictional resistance than the conventional ceramic brackets with Teflon-coated stainless steel archwires ( P P Conclusion: Metal insert ceramic bracket with stainless steel archwire is the best possible combination among the materials studied because it generated the least frictional resistance during simulated tooth movement.

Modeling and optimizing the frictional behavior of woven fabrics in climatic conditions using response surface methodology

Frictional characteristics of woven fabrics can determine smoothness and softness values of textiles. In this paper, we have studied the influence of factors such as temperature, relative humidity, fabric structure, type of fiber material, and direction of motion on roughness properties of fabric surface using response surface method (RSM). For this purpose, woven fabrics with plain, rib2/2, twill2/2, twill1/3, twill3/1, twill1/7, and twill7/1 were produced with polyester warp yarn and two different weft yarns (cotton and polyester). Then, a statistical model (RSM) was used for the experimental plan (with these variables) to determine the runs of experiment (or selected points). Next, the frictional forces measurement was carried out on the fabrics in those directions. The experimental results showed that fabric-to-fabric friction (static frictional resistance, kinetic frictional resistance, and smoothness of woven fabrics) is highly sensitive to factors like relative humidity, fabric structure, type of fiber material, and direction of motion while temperature factor (in the range 0–50°C) has no sensitive effect on frictional parameters.

Frictional Characteristics of Active and Passive Self-Ligation Bracket Systems:An in vitro Study

Self-ligating brackets are ligatureless bracket systems which are gaining immense popularity in contemporary orthodontics. Compared with conventional appliances, self-ligating mechanisms attribute their increased efficiency and reduced treatment time to their improved frictional characteristics. Aim: The present study was conducted to evaluate the kinetic frictional resistance of four self-ligating brackets: Two active types, (SpeedTM and In-Ovation® R) two passive types (Damon 3 and SmartClip) and compare them with conventional brackets ligated with elastomeric module. The brackets were tested against five different dimensions of round and rectangular stainless steel wires (0.018, 0.020, 0.017 × 0.025, 0.019 × 0.025, 0.021 × 0.025).

Frictional Resistance between Orthodontic Brackets and Archwire: An in vitro Study

The purpose of this investigation was to determine the kinetic frictional resistance offered by stainless steel and Titanium bracket used in combination with rectangular stainless steel wire during in vitro translatory displacement of brackets. In this study. Brackets: (All brackets used had a torque of - 7° and an angulation of 0°): (1) Dynalock (Unitek) 0.018'' slot, 3.3 mm bracket width, (2) Mini Uni-Twin (Unitek) 0.018'' slot, 1.6 mm bracket width, (3) Ultra-Minitrim (Dentaurum) 0.022'' slot 3.3 mm bracket width, (4) Titanium (Dentaurum) 0.022'' slot, 3.3 mm bracket width. WIRES: (1) 0.016 x 0.022'' stainless steel (Dentaurum), (2) 0.017 x 0.025''stainless steel (Unitek), (3) 0.018 x 0.025'' stainless steel (Dentaurum), elastomeric modules (Ortho Organisers), 0. 009'' stainless steel ligature wires, hooks made of 0.021 x 0.025'' stainless steel wires, super glue to bond the hooks to the base of the bracket, acetone to condition the bracket and wires before testing and artificial saliva. Brackets were moved along the wire by means of an Instron universal testing machine (1101) and forces were measured by a load cell. All values were recorded in Newtons and then converted into gms (1N-102 gm). 200 gm was then subtracted from these values to find out the frictional force for each archwire/bracket combination. For each archwire/ bracket combination three readings were taken under wet and dry condition and also with stainless steel ligature and elastomeric modules separately. The results showed that narrow brackets generated more friction than wider brackets. Frictional force was directly proportional to wire dimension. Titanium brackets generated more friction than stainless steel brackets. Archwire and bracket ligated with elastomeric module generated more friction than when ligated with stainless steel ligature wire. Frictional forces in the wet condition were greater than in the dry condition for all archwire to bracket combinations. Frictional force was seen to be inversely proportional to bracket width, frictional force was inversely proportional to bracket width, and in the wet condition were greater than in the dry condition for all archwire to bracket combinations. This study of friction is its role in lessening the force actually received by a tooth from an active component such as a spring, loop or elastic. Hence greater applied force is needed to move a tooth with a bracket archwire combination demonstrating high magnitudes of friction compared with one with a low frictional value.

Friction between various self-ligating brackets and archwire couples during sliding mechanics

The aim of this study was to evaluate the frictional resistance between active and passive self-ligating brackets and 0.019 × 0.025-in stainless steel archwire during sliding mechanics by using an orthodontic sliding simulation device. Maxillary right first premolar active self-ligating brackets In-Ovation R, In-Ovation C (both, GAC International, Bohemia, NY), and SPEED (Strite Industries, Cambridge, Ontario, Canada), and passive self-ligating brackets SmartClip (3M Unitek, Monrovia, Calif), Synergy R (Rocky Mountain Orthodontics, Denver, Colo), and Damon 3mx (Ormco, Orange, Calif) with 0.022-in slots were used. Frictional force was measured by using an orthodontic sliding simulation device attached to a universal testing machine. Each bracket-archwire combination was tested 30 times at 0° angulation relative to the sliding direction. Statistical comparisons were performed with 1-way analysis of variance (ANOVA) followed by Dunn multiple comparisons. The level of statistical significance was set at P <0.05. The Damon 3mx brackets had significantly the lowest mean static frictional force (8.6 g). The highest mean static frictional force was shown by the SPEED brackets (83.1 g). The other brackets were ranked as follows, from highest to lowest, In-Ovation R, In-Ovation C, SmartClip, and Synergy R. The mean static frictional forces were all statistically different. The ranking of the kinetic frictional forces of bracket-archwire combinations was the same as that for static frictional forces. All bracket-archwire combinations showed significantly different kinetic frictional forces except SmartClip and In-Ovation C, which were not significantly different from each other. Passive self-ligating brackets have lower static and kinetic frictional resistance than do active self-ligating brackets with 0.019 × 0.025-in stainless steel wire.

Frictional resistances of different bracket – wire combinations

Abstract Background: It has been suggested that the frictional resistance of ceramic brackets can be reduced by either lining the slots with stainless steel or by contouring the base of the slot. Objectives: The objectives of this investigation were to compare in vitro the static and kinetic frictional resistances of ceramic brackets with metal lined slots (“Clarity”, CL), stainless steel brackets (“Miniature Twin”, MT), and two ceramic brackets with different slot designs (“Contour”, CO; “Transcend”, TR). Method: Two sizes (0.018 x 0.025 inch; 0.021 x 0.025 inch) of stainless steel (SS), nickel titanium (NiTi) and ß titanium (ß-Ti) wires were drawn through the brackets. All brackets had 0.022 inch slots, and the brackets and wires were used once. The brackets were of different widths: CL, 0.180 inch; CO, 0.114 inch; MT, 0.118 inch; TR, 0.138 inch. An Instron Universal Testing Machine was used in this study. Results: There were no significant static or kinetic frictional differences when the smaller 0.018 x 0.025 inch wires were drawn through the brackets. There were no statistically significant static or kinetic frictional differences between the CL-CO, CL-MT and CO-MT bracket pairs when the 0.021 x 0.025 inch wires (SS, NiTi, ß-Ti) were used. There were no significant kinetic frictional resistance differences between the CL-TR and MT-TR when the SS wires were used. In general the static and kinetic resistances of the 0.021 x 0.025 inch wires of NiTi wire &lt; SS wire &lt; ß-Ti wire. Regardless of wire type some of the lowest kinetic resistances were found with the narrow CO brackets with the rounded slot bases. The highest static and kinetic frictional resistances were found with the wide TR bracket, and with stainless steel and ß-Ti wires. Conclusion: The high static and kinetic frictional resistances of ceramic brackets can be reduced either by lining the slots with stainless steel or by reducing the bracket width and rounding the slot base.

Development of a laboratory model to test kinetic orthodontic friction

<h2>Abstract</h2> The classic in vitro studies of frictional resistance mostly utilize straight-line traction applied to the wire-bracket-ligation interface. Reports from these studies include relative quantification of either static or kinetic frictional resistance, but do not simulate the complexity of tooth movements observed with in vivo sliding mechanics. A prototype testing apparatus was designed, fabricated, assembled, and its performance evaluated. Results of the operating friction trials are reported as a function of integrated and quantified angular and linear bracket movements. The ability to integrate, in real time, linear and angular bracket displacement while maintaining precise positional control enables previously unattainable testing of the orthodontic archwire-bracket-ligation interface. In addition, flexibility to accommodate user-specificity is a highly desirable feature. It is concluded that the testing apparatus presented has the ability to allow for a high standard of basic hypothesis testing, product development, quality control, and product performance evaluation with relative ease.

Effects of Sled Velocity on Fabric Friction.

The influence of velocity of sliding on some new frictional parameters of weft pile fabrics is reported. The frictional amplitude diminish as the velocity of motion increased. The kinetic frictional resistance also diminish initially, and then increased as the velocity of sliding increased. The initial decrease in resistance to motion is attributed to viscoelastic effects while the increase in resistance to motion at higher speeds is ascribed to mechanical interlocking of surface structure. The amplitude of frictional resistance and number of peaks are shown to be related to some partinent fabric properties such as cord height and number respectively.