Titanium Molybdenum Alloy Wires Research Articles

Torque moments and stress analysis in two passive self-ligating brackets across different incisor inclinations: A 3-dimensional finite element study

ObjectiveTo compare torque expression characteristics between rectangular slot (0.022″ x 0.028″) Damon Q passive self-ligating brackets (Ormco, Glendora, Calif) and square slot (0.021″ x 0.021″) Pitts 21 brackets (OC Orthodontics) using 0.019″ x 0.025″ Stainless Steel and 0.020″ x 0.020” Titanium Molybdenum alloy wires at various incisal inclinations using finite element analysis. The null hypothesis was that there were no differences in torque expression in both tested groups. MethodsReporting guidelines for in-silico studies using finite element analysis in medicine (RIFEM) were used. Damon Q and Pitts 21 brackets were scanned and 3D models generated. Brackets were placed on a 3-D model of a maxillary central incisor with its long axis inclined at 0⁰,5⁰,10⁰,15⁰ and 20⁰ to the occlusal plane. Final 0.019″ x 0.025″ SS and 0.020″ x 0.020” TMA archwires were inserted into slots of both tested brackets. Geometric models were converted into finite element models. Material properties were assigned for involved structures with automatic meshing performed by software. Torque movements were simulated with the FE program Ansys Space claim R 22. ResultsTorque moment values, torque expression and Von - Mises stress was higher in Pitts 21 than Damon Q at all inclination angles. There was a gradual increase in the magnitude of values with decrease in incisal inclination. ConclusionSquare slot passive self-ligating brackets show superior torque expression characteristics as compared to rectangular wire-rectangular slot combinations. The FEM results should be validated with in-vivo studies in order to confirm the findings.

To Evaluate the Effect of Prophylactic Agents on the Surface Morphology of Different Orthodontic Wires at Different Temperatures: An In vitro Study

Aim and Objective: The aim and objective are to evaluate the effect of prophylactic agents on the surface morphology of different types of orthodontic wires of different dimensions at two different temperatures. Materials and Methods: Stainless steel (SS), NiTi, and titanium-molybdenum alloy (TMA) wires of 0.016 inch round and 0.017 inch × 0.025-inch dimensions were immersed in prophylactic agents such as 0.2% NaF, 0.2% CHx and 1.23% APF for 1.5 h at 37°C and 45°C. A one-way analysis of variance, Bonferroni test, and intraclass correlation coefficient test was performed to eliminate the bias. Scanning electron microscope was used to evaluate the surface characteristics of wire and quantitative analysis was performed using ImageJ software. Results: Highest corrosion can be seen on TMA wires of 0.016 inch and 0.017 inch × 0.025 inch when exposed to 1.23% APF gel at 45°C and lowest corrosion can be seen on SS wires of 0.017 inch × 0.025 inch when exposed to 0.2% NaF mouthwash at 37°C. Conclusion: The results suggest that sodium fluoride is the mouthwash of choice when used with all three types of orthodontic wires used for different orthodontic purposes and APF gel should not be recommended when TMA wires are used at high temperatures as it causes corrosion which can lead to increased friction.

Comparing the Efficiency of a Newly Designed Spring With the T Loop for Buccal Canine Disimpaction: A Finite Element Study.

Disimpacting a buccally impacted canine precisely using frictionless mechanics is a challenge in orthodontics. Various mechanics can be used for aligning an impacted canine and a spring is one of the most versatile methods of accomplishing it. The present study describes a newly designed spring for canine disimpaction using the finite element method (FEM) model. In the present study, the efficiency of the newly designed spring was compared with the T loop. The FEM model of the maxilla was prepared. Harsha's Canine Disimpaction (HCD) spring and T loop with no pre-activation bends were utilized to disimpact the left maxillary canine usinga 0.017 x 0.025 inch titanium molybdenum alloywire. Efficiency of both springs in all dimensions (sagittal, vertical and transverse) was compared. Stressacting on the bone and teeth and number of activations needed for disimpaction were evaluated when the spring was activated by 3 mm. A movement/displacement of 0.8, 0.4and 0.1 mm was seen in the sagittal (X), transverse (Y) and vertical (Z) planes, respectively, with the HCD spring, and 0.4, 0.1and 0.1 mm seen in the X, Y and Z planes, respectively, with the T loop. A total of 12-13 and 80 activations were required as per the FEM simulation for disimpaction using the HCD spring and T loop, respectively. Stress concentration in the disto-cervical region was observed during disimpaction with both HCD spring and T loop. Within the constraints and limitations of the present study, it can be concluded that the HCD spring requires lesser activation and brings about greater control of canine disimpaction in all three dimensions when compared to the T loop.

Comparative Assessment of the Efficacy of Newly Designed Multiple Variability Loop and Opus Loop for Anterior en Masse Retraction in Orthodontics: A Finite Element Study.

Introduction Two different mechanisms are used to close the space after extractions, i.e., friction/sliding mechanics and frictionless/loop mechanics. The focus of this study is on space closure using frictionless or loop mechanics, which utilize loops to achieve the desired tooth movement. Loops are designed to increase the resiliency of the archwire so that the ideal moment-to-force ratio (M/F) of 8:1 to 10:1 for bodily tooth movement can be obtained. By incorporating various loop designs, the resiliency of archwires may be increased, and an ideal M/F ratio can be obtained. Method Different pre-activation bends were incorporated in the titanium molybdenum alloy (TMA) wire at alpha (canine side) and beta (premolar side), respectively. A total of 36 finite element method (FEM) models were prepared with and without pre-activation bends to evaluate the moment-to-force ratio. Result The results obtained from the finite element method (FEM) analysis provided valuable insights into the force and moment generated during activation while retracting the tooth. Specifically, the alpha bend at 15 degrees and the beta bend at 20 degrees produced the most desirable results for generating moments on the anterior and posterior teeth, respectively. Conclusion To ensure the proper utilization of the multiple variability (MV) loop, we recommend its preparation using a 0.019 x 0.025-inch TMA wire. This selection will maximize the loop's capabilities and enhance its performance in achieving the desired tooth movement.

Evaluation and Comparison of Momentto-Force Ratio of a New “PRP Loop” with that of Opus Loop and L LoopA Finite Element Method Study

Introduction: Extraction space closure is the foremost challenging procedure in the field of orthodontics which needs a robust understanding of biomechanics. There are two commonly used methods of space closure, one which involves friction, also called sliding mechanics, and the other is frictionless. The advantages of frictionless mechanics are there is no force loss due to friction and low anchorage taxing. The preferred method for the retraction of teeth is loop mechanics and which ensures controlled tooth movement. Aim: To evaluate and compare the Moment-to-Force (M/F) ratio of PRP loop with that of Opus loop and L loop by Finite Element Method (FEM). Materials and Methods: An in-vitro study was conducted by using FEM analysis in DMIHER University with technical assistance from the Department of Mechanical Engineering VNIT Nagpur. Computer models of Loops design were prepared on Analysis of Systems (ANSYS) version 10 (V10) software. Opus loop, L loop and Platelet-Rich Plasma (PRP) loop were modelled as SOLID 64 beam elements. Different pre-activation bends were given to the models in α and β nodes of the loop. Statistical analysis was done with Statistical Package for Social Sciences (SPSS) version 27.0 software to compare the mean of all three loops. Results: Total 36 FEM models were studied. PRP loop showed greater M/F ratio than Opus and L loop with 15ºα and 25ºβ pre-activation bends in both 0.017×0.025 and 0.019×0.025- inch Titanium Molybdenum Alloy (TMA) wire i.e., 9.09 and 9.12, respectively. On comparison of M/F ratio of PRP loop, Opus loop and L loop prepared with 0.017×0.025 and 0.019×0.025 TMA wire, at 15ºα and 25ºβ pre-activation bend in 0.019×0.025 TMA, PRP loop showed highest M/F ratio of 9.12 as compared to 0.017×0.025 TMA wire. Conclusion: The study concluded that PRP loop is an efficient retraction loop with ideal moment force ratio for translatory movement of tooth. PRP loops had highest M/F ratio than Opus loop and L loop, indicating that PRP can be used for translatory movement of tooth in wires of different materials. Therefore, for proper utilisation of PRP loop, it must be prepared with either 0.017×0.025 inch TMA or 0.019×0.025 inch TMA wire.

Identification of various orthodontic materials as foreign bodies via panoramic radiography, cone beam computed tomography, magnetic resonance imaging, and ultrasonography: an in vitro study.

We evaluated the in vitro detection sensitivity of orthodontic materials (serving as foreign bodies) using panoramic radiography, cone beam computed tomography (CBCT), magnetic resonance imaging (MRI), and ultrasonography. Five different orthodontic materials served as foreign bodies: titanium-molybdenum alloy wire (TMA; ORMCO, Orange, CA, USA; 0.017 × 0.025 in in cross-sectional dimensions and 1cm long); stainless steel bracket tooth #34 (American Orthodontics, Sheboygan, WI, USA); a monocrystalline, sapphire ceramic bracket tooth #34 (Skyortho Dental Supplies Medical, China); a polycrystalline alumina clear bracket, Damon clear bracket tooth #34 (ORMCO); and a 1 × 1 × 0.1cm polyurethane-based thermoplastic material, Invisalign clear aligner (Align Technology, San Jose, CA, USA). Panoramic radiography, CBCT, MRI, and ultrasonography were used, and four observers scored all findings independently. The TMA and stainless steel bracket were visualised in all fields by panoramic radiography and CBCT. The sapphire and Damon brackets were very clear on CBCT. The Invisalign in air was evident only on CBCT. MRI was unable to identify any material in muscle. Ultrasonography detected the TMA, sapphire bracket, and the Invisalign in muscle but only the TMA on bone. Panoramic radiography does not reveal nonmetallic orthodontic equipment in air and reveals them only poorly in muscle. CBCT was the optimal imaging modality for all materials in all fields except for the Invisalign in muscle and bone. CBCT was the only method that revealed the Invisalign in air. MRI and ultrasonography should be used to detect orthodontic materials in muscle.

Evaluation of orthodontic loads and wire–bracket contact configurations in a three-bracket setup: Comparison of in-vitro experiments with numerical simulations

So far, no practicable procedure exists to quantify the orthodontic loads applied to teeth in vivo. Dentists therefore rely on experience and simplified mechanical in-vitro experiments comprising deflection of orthodontic wires. Predicting the mechanical behaviour of orthodontic wires during clinical therapy requires understanding of the different contact states at multi-bracket–wire interfaces. This study experimentally investigates the effect of different bracket–wire contact configurations in a three-bracket setup and uses two numerical approaches to analyse and complement the experimental data. Commonly used round stainless-steel wires (diameter: 0.012″ and 0.016″) and titanium–molybdenum alloy wires (diameter: 0.016″ and 0.018″) were tested. All six force–moment components were measured separately for each of the three brackets. The results indicate that a specific sequence of distinct bracket–wire contact configurations occurs. Several transitions between configurations caused substantial changes of effective wire stiffness (EWS), which were consistent among experimental and numerical methods. The lowest EWS was observed for the configuration in which the wire touched only one wing of the lateral brackets. Taking this stiffness as 100%, the transition to a configuration in which the wire touched two opposing wings of the lateral brackets resulted in an increase of EWS of 300% ± 10%. This increase was independent of the wire type. Additional contacts resulted in further increases of stiffness beyond 400%. The results of this combined experimental and numerical study are important for providing a fundamental understanding of multi-bracket–wire contact configurations and have important implications for clinical therapy.

Comparison of frictional resistance between four types of brackets in combination with stainless steel and beta-titanium archwires

Objectives: The objective of the study was to evaluate and compare the frictional resistance generated by four different types of brackets in combination with stainless steel (SS) and titanium molybdenum alloy (TMA) archwires. Materials and Methods: Maxillary premolar brackets were used in this study. These brackets were divided into eight groups comprising seven samples each. Of the eight groups, four groups were combined with SS and four groups were combined with TMA archwires. The testing was done in the presence of human saliva. The static frictional resistance was calculated for each group. One-way ANOVA and post hoc Tukey tests were done to compare the friction generated by each group. Results: There was a statistically significant difference between the friction generated by the monocrystalline brackets and the other bracket groups (P < 0.001). There was no statistically significant difference in static friction generated between self-ligating and conventionally ligated brackets. There was a statistically significant difference between the frictional resistance produced by SS and TMA wires (P = 0.02) with regard to monocrystalline ceramic brackets only. Conclusion: Monocrystalline ceramic brackets (Radiance) were found to generate the highest frictional resistance during sliding mechanics when compared to other brackets in combination with both SS and TMA wires. Self-ligating brackets did not show a statistically significant reduction in friction when compared to conventional ligation. There was a statistically significant difference between SS and TMA wires when used with monocrystalline brackets.

Comparison of force loss during sliding of low friction and conventional TMA orthodontic archwires : An invitro study.

ObjectiveThe goal was to measure and compare the amount of force loss during tooth movement guided by archwires, including a newly introduced low-friction titanium molybdenum alloy (TMA), conventional TMA, and stainless steel archwires.MethodsThe force loss was measured using a specialized biomechanical set-up, the orthodontic measurement and simulation system (OMSS). A total of 30 specimen were used (10 low-friction TMA (TMA-Low), 10 conventional TMA (TMA-C), and 10 stainless steel (SS) archwires, each having a dimension of 0.016 × 0.022 inches). The conventional and low friction TMA archwires served as test groups, while the SS archwires served as the control group.ResultsThe mean values of force loss between the three types of wires (TMA‑C, TMA-Low, and SS) were significantly different (p < 0.0001). The highest mean force loss during sliding movement was found in the conventional TMA group (72.1%), followed by low friction TMA (48.8%) and stainless steel wires (33.7%) in a descending order.ConclusionThe friction property of the low friction TMA archwire was superior to the conventional TMA archwire but was still inferior to the stainless steel archwire.

Tensile strength differences between nickel-titanium and titanium molybdenum alloy orthodontic archwire after immersion in detergent toothpaste

Background: Titanium-based alloys, such as nickel-titanium (NiTi) and titanium molybdenum alloy (TMA), have gained immense popularity in the last decades. Some toothpaste ingredients can negatively affect orthodontic procedures. Objective: The objective of this study was to examine the differences in tensile strength between NiTi and TMA orthodontic wires after immersion in detergent toothpaste. Methods: Six treatment groups were established, with NiTi and TMA wires immersed in 25 g detergent toothpaste for 4, 8, and 12 h. Tensile strength measurements were carried out using a Tensilon RTF-1350 universal testing machine. Results: The P values of the NiTi and TMA wires were as follows: 0.000 after 4 h, 0.000 after 8 h, and 0.002 after 12 h. These results showed that there were significant differences between the tensile strength of NiTi and TMA orthodontic wires after immersion in detergent toothpaste for increasing periods of time. Conclusion: The tensile strength of NiTi wire was greater than the tensile strength of TMA archwire. However, detergent toothpaste did not have a significant effect on change in tensile strength of NiTi and TMA wire.

In Vitro Comparative Evaluation of Frictional Resistance of Connecticut New Arch Wires, Stainless Steel and Titanium Molybdenum Alloy Archwires Against Different Brackets.

Background and objectivesFriction between the bracket and archwire during sliding mechanics is of great concern in orthodontics, as it reduces the effectiveness of the orthodontic appliance and slows down tooth movement. The aim of this study was to evaluate frictional resistance of stainless steel (SS), titanium molybdenum alloy (TMA), and Connecticut new arch (CNA) wires against SS and ceramic brackets. The surface textures of the brackets and wires were also evaluated by scanning electron microscopy (SEM) before and after testing.MethodA total of 180 premolar brackets of SS (ORMCO Corp., Orange, CA) and 180 ceramic (3M Unitek, Maplewood, MN) with a 0.022-inch slot and 180 SS, TMA, and CNA wires of 0.017 x 0.025 inches and 0.019 x 0.025 inches were tested. The SS brackets and ceramic brackets were bonded onto the SS bar with cyanoacrylate adhesive with the help of a jig. The wire assembly was vertically mounted and clamped to the jaws of the universal testing machine with 10 N load cell, and friction was measured along with other readings. The surface roughness of brackets and wires were examined using SEM in 200 X magnification before and after testing.ResultsTMA wire showed the greatest frictional force compared to SS and CNA wire. The frictional force was greater in the 0.019 x 0.025-inch wire compared to the 0.017 x 0.025-inch wires. The highest frictional force was noted in the SS bracket and 0.019 x 0.02-inch TMA wire combination. A statistically significant difference was not seen between the SS bracket and 0.019 x 0.025-inch SS wire and the 0.019 x 0.025-inch CNA wire combinations.SEM showed that the TMA archwire had the roughest surface area compared to SS and CNA wires, and the ceramic bracket had more surface roughness than the SS bracket.ConclusionCNA wire demonstrated frictional resistance similar to the SS wire. CNA wire can be used instead of TMA wire because of its better range of action, high spring back, and less frictional resistance for space closure in sliding mechanics.

Effect of oral environment and prescribed fluoride mouthwashes on different types of TMA wires - An in-vivo study.

OBJECTIVE:The aim of this study was to investigate the effect of intraoral conditions and fluoride mouthwashes on mechanical properties and surface characteristics of different types of titanium molybdenum alloy (TMA) wires.MATERIALS AND METHODS:Three types of TMA wires of dimension 0.017” × 0.025” [1. Standard TMA (TMA), 2. ion-implanted, low-friction TMA (LF) and 3. Colored, Honey Dew TMA (HD)] were tested in three conditions as three groups; A) Control (as received), B) No fluoride (following intraoral use without fluoride) and C) Fluoride (following intraoral use with fluoride rinses). Surface roughness was evaluated using 3D Optical Profilometer. Three point bending tests were done to evaluate load deflection characteristics (LDR), ultimate tensile strength (UTS), and Young's modulus (E). Statistical evaluation was done using one-way analysis of variance (ANOVA), Bonferroni multiple comparison, and paired t-tests.RESULTS:Control group TMA exhibited significantly higher surface roughness, peak height, and LDR as well as lower UTS and E when compared to LF and HD (P < 0.001). In nonfluoride group, the surface roughness and LDR increased significantly for all three types of wires (P < 0.001). The UTS and E showed a significant decrease (P < 0.001). Additional use of fluoride mouthwashes (fluoride group) further increased surface roughness and LDR and decreased the UTS and E (P < 0.001).CONCLUSION:The ion-implanted LF/HD varieties had better surface smoothness, lower LDR, higher UTS, and higher E than standard TMA in the control group, pointing towards a better efficiency of these wires. Intraoral conditions significantly increased surface roughness and deteriorated mechanical properties of all types of TMA wires. With the use of daily fluoride mouthwashes, the deterioration was much worse.

Comparison of spring characteristics of titanium-molybdenum alloy and stainless steel.

[This retracts the article on p. 84 in vol. 9, PMID: 28149469.].

Evaluation of kinetic friction between regular and colored titanium molybdenum alloy archwires.

The aim of this study was to evaluate the kinetic frictional properties of colored titanium molybdenum alloy (TMA) archwires (purple-coated TMA and honey dew-coated TMA) and the regular TMA archwires. The experiment comprised of three groups, Group I - Regular TMA archwires, Group II - Purple-coated TMA archwires, Group III - Honey dew-coated TMA wires involving 21 samples each that were evaluated for their frictional properties using Instron Universal Testing Machine. The results were subjected to statistical analysis using analysis of variance wherein Group I Regular TMA wires revealed mean kinetic frictional value of 8.236 N and a standard deviation of 0.4038 N, while Group II (purple-coated TMA wires) showed a mean value of 5.297 N, standard deviation of 0.3128 N and Group III (honey dew-coated TMA wires) showed a mean value of 4.206 N and a standard deviation of 0.5353 N. The kinetic frictional values are higher for regular TMA wire exhibiting superior characteristic of color-coated TMA. Wires exhibiting superior characteristics are color-coated TMA wires, especially honey dew-coated TMA wires over the regular and purple-coated TMA wires. These superior properties of newly introduced wires can be considered for its application in both details friction and frictionless mechanics in retraction phase of fixed orthodontic treatment.

Comparison of spring characteristics of titanium-molybdenum alloy and stainless steel.

BackgroundTitanium-molybdenum alloy (TMA) and stainless steel (SS) wires are commonly used in orthodontics as arch-wires for tooth movement. However, plastic deformation phenomenon in these arch-wires seems to be a major concern among orthodontists. This study aimed to compare the mechanical properties of TMA and SS wires with different dimensions.Material and MethodsSeventy-two wire samples (36 TMA and 36 SS) of three different sizes (19×25, 17×25 and 16×22) were analyzed in vitro, with 12 samples in each group. Various mechanical properties of the wires, including spring-back, bending moment and stiffness were determined using a universal testing machine. Student’s t-test showed statistically significant differences in the mean values of all the groups. In addition, metallographic comparison of SS and TMA wires was conducted under an optical microscope.ResultsThe degree of stiffness of 16×22-sized SS and TMA springs was found to be 12±2 and 5±0.4, respectively, while the bending moment was estimated to be 1927±352 (gm-mm) and 932±16 (gm-mm), respectively; the spring-back index was determined to be 0.61±0.2 and 0.4±.09, respectively (p<0.001). There were no statistically significant differences in spring-back index in larger dimensions of the wires.ConclusionsSystematic analysis indicated that springs made of TMA were superior compared to those made of SS. Although both from economic and functionality viewpoints the use of TMA is suggested, further clinical investigations are recommended. Key words:Bending moment, optical microscope, spring-back, stainless steel, stiffness, titanium‒molybdenum alloy.

Microscopic study of surface roughness of four orthodontic arch wires

Aim/purpose Comparative evaluation of surface roughness of stainless steel (SS), nitinol (NiTi), titanium molybdenum alloy (TMA) and copper nitinol (Cu NiTi) orthodontic arch wires before and after clinical use to find the smoothest wire surface best used in orthodontic sliding mechanics. Materials and methods Surface roughness of 40 arch wires divided into four groups (group 1: 10 SS arch wires, group 2: 10 NiTi arch wires, group 3: 10 TMA arch wires and group 4: 10 Cu NiTi arch wires) were measured at five different points for each wire before and after its clinical use in oral cavity for 4 weeks using atomic force microscope and optical digital microscope. All obtained data was statistically tested. Results SS arch wires had the smoothest surface (average roughness: 17.38 μm for new wires and 104.1 μm for used wires) and Cu NiTi arch wires had the roughest surface (average roughness: 221.12 μm for new wires and 499 μm for used wires) with high significant differences between both groups either new or used arch wires (P < 0.001). High significant difference was found between new and used wires for all groups. NiTi wires had greater surface roughness (average roughness: 211.8 μm for new wires and 313.8 for used wires) than TMA wires (average roughness: 138.5 μm for new wires and 221.2 μm for used wires). Conclusion SS orthodontic arch wires exhibited the least amount of surface roughness and advocated to be used in sliding mechanics to minimize the friction during orthodontic tooth movements.

In vitro biomechanical analysis of torque capabilities of various 0.018″ lingual bracket-wire systems: total torque play and slot size.

To determine the total torque play of various rectangular titanium molybdenum alloy (TMA)/stainless steel (SS) wires in various 0.018″ upper incisor lingual brackets and slot size measurements. TMA (0.0175″ × 0.0175″, 0.0170″ × 0.025″, 0.0182″ × 0.0182″, 0.0182″ × 0.025″) and SS wires (0.016″ × 0.022″, 0.016″ × 0.024″, 0.018″ × 0.025″) were twisted in standard (Hiro, Incognito™, Joy®, Kurz 7th generation, STb™: fixation with elastic modules) and self-ligating brackets (Evolution SLT®, In-Ovation® L MTM: closed ligation mechanism) from -20 degrees to +20 degrees with a custom-made machine. The total torque play was calculated by extrapolating the linear portion of the twist/moment curves to the x-axis and adding the absolute negative and positive angle values at the intercepts. The bracket slot height was measured before and after the experiments with a series of pin gauges with round profile. Brackets in ascending order for total torque play with the most slot-filling wire TMA 0.0182″ × 0.025″: Evolution SLT® (0 degree ± 0 degree), Incognito™ (2.2 degrees ±1.1 degrees), Hiro (5.1 degrees ±3.0 degrees), In-Ovation® L MTM (6.3 degrees ±2.2 degrees), STb™ (6.6 degrees ±1.8 degrees), Kurz 7th generation (7.1 degrees ±0.8 degrees), and Joy® (12.0 degrees ±0.8 degrees). Wires in ascending order for total torque play with the most precise slot Incognito™: TMA 0.0182″ × 0.025″ (2.2 degrees ±1.1 degrees), TMA 0.0182″ × 0.0182″ (2.4 degrees ±0.9 degrees), SS 0.018″ × 0.025″ (5.5 degrees ±1.0 degrees), TMA 0.0170″ × 0.025″ (9.4 degrees ±1.8 degrees), TMA 0.0175″ × 0.0175″ (13.0 degrees ±1.5 degrees), SS 0.016″ × 0.024″ (16.1 degrees ±1.4 degrees), SS 0.016″ × 0.022″ (17.8 degrees ±1.0 degrees); differences between some of the experimental groups were not statistically significant. Bracket slot dimensions in ascending order: Evolution SLT® (less than 0.452mm), Incognito™ (0.460mm ±0.002mm), In-Ovation® L MTM (0.469mm ±0.001mm), Hiro (0.469mm ±0.010mm), STb™ (0.471mm ±0.002mm), Kurz 7th generation (0.473mm ±0.002mm), and Joy® (greater than 0.498mm). The applied method must be questioned when used with brackets with incomplete slot walls (Evolution SLT®). Slot measurement with pin gauges may not register bracket wing deformation. All brackets showed a differing slot size from the nominal 0.018″ (0.457mm). Incognito™ presented the most precise and Joy® the widest slot. The main wires for the retraction phase SS 0.016″ × 0.022″/SS 0.016″ × 0.024″ showed poor torque control. Among the finishing TMA wires, TMA 0.0175″ × 0.0175″ exhibited the highest and TMA 0.0182″ × 0.0182″/TMA 0.0182″ × 0.025″ the smallest torque play. The manufacturers could profit from this investigation towards optimization of the dimensional precision of their products. The orthodontist must be aware of the torque play of the wire-bracket combinations to be able to plan and individualize the appliance by third order customization.

The effect of red wine extract, resveratrol, on the degree and rate of orthodontic tooth movement in guinea pigs

ObjectiveAn animal trial, its protocol approved by the Institutional Animal Care and Use Committee of the U.P. National Institutes of Health (IACUC Protocol No. 2010-008), was employed to investigate the effects of resveratrol on the degree and rate of orthodontic tooth movement in guinea pigs.Materials and MethodsEighteen male adult guinea pigs were randomly allocated into 3 groups: low dose, high dose, and control groups. A 0.016″ titanium molybdenum alloy wire formed into a helical torsion spring with a coil, with the loops cemented onto the maxillary incisors of the animals, served as the orthodontic appliance. Daily oral administration of resveratrol was provided to the low dose (0.047 mg/kg) and high dose (0.47 mg/kg) groups, while water was provided to the control group. Measurements were taken everyday at the interproximal area at the level of the incisal edge using a measuring caliper.ResultsThe results of the ANOVA showed no statistically significant differences in the mean measurements of tooth separation among the three groups from day 2 (P=0.966) to day 8 (P=0.056). However, starting from day 9 (P=0.049) until day 18 (P=0.000), there was a significant difference in the mean tooth separation among the test groups.ConclusionUsing the LSD, it was noted that the low dose and the high dose groups have similar degrees of mean tooth separation, with the control group being significantly different from the two.

Effects of diferent salivary ph on the surface and roughness of different orthodontic wires

AIM: The aim of this study was to evaluate the effects of different salivary pH on the surface of orthodontic wires. MATERIAL AND METHODS: Two hundred and seventy wire segments of titanium-molybdenum alloy (TMA), and Cr-Ni stainless steel , subjected to saliva pH 2.0 , 5.0 and 7.6 , in three different times of storage, divided into 3 groups (n=30). Group 1: TMA (Morelli), Group 2: TMA (Ormco) and Group 3: Stainless steel Cr-Ni (Morelli). To read the roughness profilometer was used Mitutoyo Surftest Digital-301. Observation of the surface morphology was performed by scanning electron microscope (SEM). RESULTS: Between the results is that the lower the pH more roughness was found. No changes were observed on the wires roughness of group 3. In the evaluation of SEM, changes were found in surface TMA wires in pH 2 and 5, the steel wires no changes superficias. CONCLUSION: The acidic pH and time showed effects on TMA’s wires. The stainless steel wires showed no changes. We conclude that the stainless wires have greater resistance to salivary pH.

Double-Loop Technique Using Titanium Molybdenum Alloy Wire for Fabrication of Nasal Stents in Nasoalveolar Molding Therapy for Cleft Lip and Palate Patients

This article presents a technique for fabricating a modified nasoalveolar molding appliance using 0.032-inch titanium-molybdenum alloy wire for nasal stents incorporating a double loop. The nasal stents are included in the acrylic molding plate at the time the appliance is inserted. The acrylic retention button used in a conventional appliance is replaced by a simple retention hook fabricated using titanium-molybdenum alloy wire. This technique is an effective alternative to a conventional appliance, and it simplifies the appliance-modification process during follow-up visits.