Mechanical Properties and Clinical Significance of Orthodontic Wires

Orthodontic treatment is usually conducted by applying forces to certain teeth to move them into a targeted position. Orthodontic wires have been reported to be the primary modalities used in fixed-appliances-based orthodontic treatment to induce favorable tooth movement events. Accordingly, acquiring adequate knowledge about these approaches' clinical applications and biochemical behavior is essential when planning for a successful orthodontic treatment. Orthodontic wires are widely used and are mainly composed of composites, polymers, alloys and metals. Accordingly, the physical properties and clinical application of orthodontic wires vary based on their composition. In this context, it was recommended that achieving favorable outcomes of orthodontic treatment obliges clinicians to decide the best orthodontic wire and treatment plan based on the chemical properties and related clinical applications of each wire. Therefore, wires that tend to produce increasing stiffness gradually are generally used. However, it should be noted that no ideal wire exists. Therefore, favoring the application of a wire over the other should be based on the intended outcomes and stage of the treatment process.

Effect of the bracketless orthodontics technique and resin composite material on the biomechanical response of the upper central incisor: 3D finite element analysis

Objectives: The bracketless orthodontic treatment (BOT) is an alternative technique which indicates using an orthodontic appliance composed of wires and composite resin assisted by 3D technology. However, the biomechanical response of central incisor orthodontic movement has yet to be investigated. Thus, the aim of the present investigation was to calculate the stress magnitude in central incisor movement through 3D finite element analysis using different wire diameters (0.012”, 0.014”, and 0.016”) of nickel–titanium wire and two different resin composites (Opallis and Filtek). Materials and Methods: A 3D volume composed of enamel, dentin, cortical bone, cancellous bone, periodontal ligament, composite resin, and different orthodontic wire diameters was designed. After the modeling process, the models were exported to computer-aided engineering software divided into a finite number of elements, and a mechanical structural static analysis was conducted. Results: The stress results were plotted on colorimetric maps and in tables for comparison between the different models. The results showed that the central incisor orthodontic movement with BOT does not induce damage to the periodontal ligament, dental root, or bone tissue, regardless of the simulated orthodontic wire diameter and resin composite materials. The palatal composite resin and orthodontic wire also presented acceptable stress magnitude during orthodontic movement. Conclusion: Thus, the BOT technique promoted a suitable biomechanical response during central incisor movement regardless the resin composite.

Titanium Nitride Plating Reduces Nickel Ion Release from Orthodontic Wire

The leaching of metal ions from orthodontic appliances is a problem for their use in patients with metal allergies. Despite the development of a number of non-metal orthodontic appliances, including brackets, non-metal wires are not yet available. Therefore, it is necessary to modify the surfaces of orthodontic wires to prevent the leaching of metal ions into the oral environment for use in such patients. This study was performed to examine whether plating of orthodontic wire with titanium nitride (TiN), which does not impair its mechanical properties, could prevent the leaching of metal ions from the wire on immersion in acid. To investigate the acid corrosion resistance of the wire, the amount of metal ions eluted from the wire immersed in acid was measured by using inductively coupled plasma mass spectrometry (ICP-MS) and the dimethylglyoxime (DMG) test, the properties of the wire surface were examined by stereomicroscopy and scanning electron microscopy, and the surface roughness was measured using a surface roughness tester. The results indicated that TiN plating of orthodontic wire significantly suppressed the elution of metal ions on immersion in acid.

FRACTURE LOAD OF SILVER SOLDERED JOINTS ON STAINLESS STEEL AND COBALT-CHROMIUM ORTHODONTIC WIRES WITH VARIOUS JOINING CONFIGURATIONS

The current research compared and analysed the tensile strength of silver soldered stainless steel and cobalt-chromium orthodontic wire joints with band material The effect of joint site planning on various orthodontic joining configurations was investigated. A total of sixty wire specimens were chosen, thirty in the stainless-steel group and thirty in the cobalt – chromium group. Again, each group's sample was divided into three subgroups, namely End – End, Round, and Orthodontic band material. The study findings suggested all three configurations can be used to make silver soldered joints regardless of the wire consistency. When subjecting the wire to joint site planning, however, stainless steel wire should be used with its limitations in mind.

FRACTURE LOAD OF SILVER SOLDERED JOINTS ON STAINLESS STEEL AND COBALT-CHROMIUM ORTHODONTIC WIRES WITH VARIOUS JOINING CONFIGURATIONS

The current research compared and analysed the tensile strength of silver soldered stainless steel and cobalt-chromium orthodontic wire joints with band material The effect of joint site planning on various orthodontic joining configurations was investigated. A total of sixty wire specimens were chosen, thirty in the stainless-steel group and thirty in the cobalt – chromium group. Again, each group's sample was divided into three subgroups, namely End – End, Round, and Orthodontic band material. The study findings suggested all three configurations can be used to make silver soldered joints regardless of the wire consistency. When subjecting the wire to joint site planning, however, stainless steel wire should be used with its limitations in mind.

THE INFLUENCE OF LEMON (Citrus Limon (L.)) IRON ION (Fe) REMOVAL ON STAINLESS STEEL ORTHODONTIC WIRE

Background: Lemons consist of 5-8% citric acid, have a pH of around 2.74. Drinks that have a critical pH of 5.5 can be said to be acidic drinks. Acidic drinks have the potential to cause corrosion of teeth and dental materials, one of which is stainless steel orthodontic wire. Stainless steel orthodontic wire is easily corroded, the wire has a composition of 71% Iron (Fe), 18% Chromium (Cr), 8% Nickel (Ni), and 0.2% Carbon (C). Corrosion is caused by the presence of inorganic components that act as electrolyte media that can trigger electrochemical reactions.Method: Each sample was placed on each uninsulated petridish and labeled as a marker. This is done by inserting orthodontic wire which is immersed into the incubator for 3.5 hours at 37℃. Then the sample is taken and the separation between the sample and the solution is carried out. After that, the measurement of Iron (Fe) ions was carried out using the Atomic Absorption Spectrophotomery tool.Result: The results showed the average release of Iron (Fe) ions in the experimental group of lemon juice with a concentration of 25% was 0.067mg/L, a concentration of 50% was 0.090mg/L and a concentration of 100% was 0.135mg/L. The test results obtained using the One Way Anova test showed that there was no significant difference (p>0.05).Conclusion: There was no significant difference in the release of Iron (Fe) ions in stainless steel orthodontic wires between experimental groups, and there was no effect of soaking lemon juice (Citrus Limon (L.)) on the release of Iron (Fe) ions in stainless steel orthodontic wires.

Vertical and Orovestibular Forces Generated by Beta-Titanium and Stainless-Steel Rectangular Wires in Labial and Fully Customized Lingual Bracket Systems

This study aimed to investigate the force values exerted from rectangular wires when combined with conventional labial and fully customized lingual appliances under predefined, idealized activation. Fully customized lingual brackets of two brands Incognito™ (3M Unitek, Monrovia, MN, USA) and WIN (DW Lingual Systems, Bad Essen, Germany) and labial brackets of another brand, discovery® MIM and discovery® smart systems (Dentaurum, Ispringen, Germany), were chosen. Stainless-steel and beta-titanium wires of 0.018” × 0.025” were examined. For IncognitoTM, 0.0182” × 0.025” beta-titanium wires were tested. Intrusion/extrusion and orovestibular movements were performed in a range of 0.2 mm, and the forces were recorded for each 0.1 mm of the movement. Mean values and standard deviations were calculated for all measurements, and ANOVA was performed for statistical analysis. Slight differences were observed between the forces generated from beta-titanium and stainless-steel wires. The same wire generated in some cases 5–53% higher forces with the lingual appliance due to the vertical orientation of the long walls during intrusion/extrusion and increased wire stiffness at the anterior region. Beta-titanium and stainless-steel 0.018” × 0.025” wires can generate similar force values during the final stages of the orthodontic therapy; thus, possibly only one of the two alloys could be used in each orthodontic wire sequence.

Comparing flipped classroom and conventional live demonstration for teaching orthodontic wire-bending skill

Flipped classroom may overcome weaknesses of live demonstration in teaching orthodontic wire-bending. This study aims to compare the effectiveness between flipped classroom and live demonstration in transferring skills for fabricating Adams clasp. Forty third-year undergraduate dental students were assigned to two groups. The students in group LD (n = 20) attended a live demonstration while students in group FC (n = 20) attended a flipped classroom. Both groups were taught on skills to fabricate Adams clasp in a standardised way. Each student from both groups were asked to submit an Adams clasp for a blinded quality assessment by two trained and calibrated assessors using a 18-item rubric, followed by validated students’ satisfaction questionnaires to evaluate their perceived satisfaction on the teaching method received. A crossover study was then conducted three weeks later where LD attended a flipped classroom while FC attended a live demonstration. Students’ satisfaction questionnaires were again collected from each student for blinded analysis. Mean scores for the quality of Adams clasp were 9.775 and 9.125 for LD and FC, respectively. No significant difference was detected between the two groups. Statistically significant association was found for one statement on the questionnaire, “I found the classroom arrangements conducive for the wire-bending activity” (p = 0.010). No significant differences were found between the two groups for other statements (p > 0.05). In conclusion, within the limitations of the study, flipped classroom is equally effective as conventional live demonstration in transferring orthodontic wire-bending skills for fabrication of Adams clasp. However, students perceived the classroom arrangements during the flipped classroom significantly more conducive for teaching orthodontic wire-bending.