Archwire Research Articles

Effectiveness of coatings in reducing biofilm adhesion on arch wires: A systematic review

To evaluate the Effectiveness of coatings in reducing biofilm adhesion on arch wire. A literature search was performed on PubMed, Medline, Google Scholar, and Science Direct to examine studies that compared the uncoated group of arch wires to those with nano coatings and assessed the anti-adherent property. After extracting the data from each study, two risk of bias assessment tools were employed and tabulated data was obtained. 8 Studies met the requirements for inclusion. For majority of the included articles, the risk of bias assessment indicated a low to moderate risk. The antibacterial properties of various nanoparticle coatings were examined and evaluated.Regardless of patient compliance, a proper application of each type of coated arch-wire can help prevent white spot lesions and reduce bacterial aggregation around orthodontic attachments. Majority of the studies that made up this systematic review have a risk of bias grade of "fair." A meta-analysis was not feasible because of heterogeneity in the different coating techniques used to test the antibacterial property.

Comparison of Bacterial Adherence on Different Archwires after Clinical Use

ABSTRACT Background: An essential component of orthodontic therapy, orthodontic archwires may operate as surfaces for bacterial adhesion, which might result in issues with oral health. Materials and Methods: This study assessed the bacterial adhesion to three different kinds of orthodontic archwires: beta-titanium (TMA), nickel-titanium (NiTi), and stainless steel (SS). At the conclusion of the clinical usage period, samples of each kind of archwire were gathered and submitted to microbiological investigation in order to determine the quantity of adhering bacterial colonies. Using scanning electron microscopy (SEM), the surface properties of the archwires were evaluated after usage. Results: The three kinds of archwires had significantly different rates of bacterial adhesion, according to the findings. With an average of 1500 ± 50 CFU/mm2, SS archwires showed the highest level of bacterial adhesion, followed by NiTi archwires at 1100 ± 45 CFU/mm2. The least amount of bacteria adhered to TMA archwires, with an average of 800 ± 30 CFU/mm2. According to SEM pictures, the degree of bacterial adhesion was associated with the archwires’ surface roughness, with smoother surfaces showing less bacterial colonization. Conclusion: In comparison with SS and NiTi archwires, the research finds that TMA archwires are linked to the least amount of bacterial adhesion.

A COMPARATIVE STUDY OF THE SURFACE OF FACTORY AND HAND-MADE LOOPS ON TITANIUM-MOLYBDENUM ORTHODONTIC ARCHWIRE

The most important part of the brackets, used in orthodontic treatment, is the archwire, which, when activated, generate light and long-lasting biomechanical forces that make the teeth move. Different manufacturers offer ready-made expensive solutions for orthodontists - archwire with loops along the length of the wire of different shape, which increases the cost of treatment. However, orthodontic practice is strictly individual, depending on the patient’s orthodontic problems, the stages and methods of treatment.Orthodontists often have to choose between expensive archwires with pre-made loops or using an archwire that they can manually bend in the right places depending on the patient’s individual characteristics and specific needs. In this case, the orthodontist’s decision depends on preserving the quality of the archwire surface. The surface roughness of the orthodontic archwire plays an important role in the bracket-archwire complex and is an essential factor that determines the effectiveness of the guided movement of the teeth along the arch. Surface roughness not only affects the efficiency of sliding mechanics, due to frictional effects, but also corrosion behaviour and aesthetics. A comparison of the surface characteristics of Ti-Mo archwire - with factory and hand-made loops is made. The surface of the archwire in the bending zones of the loops was investigated by SEM analysis and Surface roughness analysis. The analysis of the results shows that manual bending practically does not change the surface of the archwire, does not introduce additional defects that increase the contact friction, as well as create conditions for faster deterioration of properties and the undesirable breakage of the archwire. Research results give orthodontists confidence that the manual bending process does not degrade the quality of the archwire surface. The hand-bent archwire preserves the possibility of trouble-free movement in the braces when tightening or loosening during the different stages of treatment.

The Effect of Three Metal Oxide Nanocoatings on the Frictional Resistance of Superelastic Orthodontic Archwires: A Comprehensive In vitro Analysis.

To evaluate and compare the impact of nanocoatings made of oxides of Aluminum, Titanium, and Zirconium, on the frictional resistance on three types of superelastic orthodontics archwires namely; nickel titanium, copper nickel titanium and low hysteresis nickel titanium. There are120 archwire segments of equal dimensions were divided into four groups (n = 30) with 10 samples each of low hysteresis superelastic archwires; NiTi archwires and CuNiTi archwires. While group A were uncoated, other groups were nanocoated with group B: Aluminum oxide; group C: Titanium dioxide; group D: Zirconium oxide respectively. Upper premolar metal brackets MBT 0.022 slot were used for testing. The frictional properties of the archwires were measured using a Universal testing machine equipped with a custom-made jig. Statistical tests including analysis of variance and post hoctests were used for analysis. The least frictional resistance among the three types of archwires was seen with low hysteresis(L&H) NiTi wires coated with ZrO2 (3.1253 ± 0.45822 N) and the highest with uncoated CuNiTi archwires (7.1113 ± 1.29031 N). Among the nanocoatings, the least value was found for ZrO2 nanocoatings followed by TiO2, Al2O3 and highest with uncoated archwires across all three types of archwires. Low hysteresisNiTi have the least frictional resistance compared to CuNiTi and NiTi archwires. The findings also suggest that all the three metal oxide nanocoatings reduce frictional resistance significantly, among which, ZrO2 nanocoatings were the most effective. This study underscores the potential efficacy of metal oxide nanocoatings in reducing archwire friction and, consequently, will improve orthodontic treatment efficiency and patient comfort. How to cite this article: Dilip S, Rajkumar K. The Effect of Three Metal Oxide Nanocoatings on the Frictional Resistance of Superelastic Orthodontic Archwires: A Comprehensive In vitro Analysis. J Contemp Dent Pract 2024;25(7):649-655.

Cytotoxicity of Orthodontic Archwires Used in Clinical Practice: In Vitro Study

This study investigates the cytotoxicity of various orthodontic archwires, which are essential in directing tooth movement through biomechanical forces. With advancements in material science, different archwire materials have been developed to balance mechanical performance with aesthetic and biological considerations. The study focuses on evaluating the biocompatibility and mechanical properties of stainless steel, nickel–titanium, and chromium–cobalt archwires, particularly their cytotoxic effects on oral cavity cells. In vitro cell culture experiments with fibroblasts, combined with scanning electron microscopy (SEM) analysis, were conducted to assess cell viability and morphology. The results revealed significant differences in cytotoxicity, with copper wires showing high toxicity and causing extensive cell death, while nickel–titanium and chromium–cobalt wires supported better cell viability and healthier cell morphology. These findings highlight the importance of selecting archwire materials that ensure mechanical efficiency without compromising cellular health, emphasizing the need for ongoing assessment of material biocompatibility in the oral environment.

Comparison of Friction Resistance Between Different Bracket Systems: An In Vitro Study

Introduction The efficiency of tooth movement associated with orthodontic sliding mechanics can be compromised by friction between archwire and tube or bracket slot. Orthodontic brackets and archwires are important constituents of an orthodontic appliance system. Friction is an uncontrolled variable of particular interest when continuous arch techniques are used to align and move teeth by way of sliding a tube or bracket along an arch. Aim and Objectives Comparison of frictional resistance between different bracket systems of 3M and MO brands in combination with different wires of 3M, MO, and G&H brands. Evaluation of frictional resistance between two different types of bracket systems and different types of wire combinations. Materials and Methods Two types of bracket systems were used: metal bracket system and ceramic bracket system (3M and MO brands). Four different orthodontic wire alloys were used: stainless steel (SS), TMA, NiTi, and CuNiTi (3M, MO, and G&H brands). A rectangular block made up of self-cure acrylic resin was designed to hold the bracket during the mechanical test. Each bracket base was glued to an acrylic block with cyanoacrylate glue. The wire segment was inserted into the bracket and was ligated passively with SS ligature wire. The bracket–wire combination was submitted to mechanical tests with a universal testing machine. One end of the acrylic block was mounted to the lower grip of the universal testing machine. The free end of the archwire was fixed to the upper grip of the universal testing machine. The friction which was generated between the wire and bracket was measured under dry conditions and at room temperature. The test wire was pulled through the bracket at a speed of 0.5 cm/min. The load cell registered a maximum force level. This data was stored in the computer and was submitted to statistical analysis, and parameter tests were applied. Results The highest mean friction resistance of 5.998 N was generated by group B2-E2 (ceramic bracket – MO + TMA archwire – MO). The lowest mean friction resistance of 2.552 N was generated by group A1-C1 (metal bracket – 3M + SS wire – 3M). There was a statistically significant difference between the friction generated by the metal bracket on SS archwire and the ceramic bracket on TMA archwire regardless of 3M or MO brand material ( p value < .0001) and metal bracket ( p = .0004).

Nanomechanical and bending properties of nickel-titanium orthodontics archwires by depth-sensing indentation

This study aimed to identify the link between alloy microstructures and the nanomechanical properties of different orthodontic archwires containing nickel-titanium (NiTi) by sensing sliced areas. Previous studies have focused on analyzing and contrasting physical properties such as microhardness, elasticity modulus, and resistance; therefore, the trend is to consider microstructural characteristics in detail. Thirty archwire samples from 3 different commercial brands, American Orthodontics (AO), 3M Unitek (3M), and Borgatta, were analyzed through scanning electron microscopy and energy-dispersive x-ray spectroscopy, transmission electron microscopy, atomic force microscopy, Berkovich nanoindentation, and microtensile microscopy to determine their chemical-crystallographic characteristics and nanomechanical and bending characteristics. The identified formulations of AO and 3M had averages of 20 wt%, for Ni and 15.4 wt% for Ti, with lower concentrations for Borgatta. Alloys of Ni and Ti were distributed in different concentrates in the matrix of the archwires. The nanomechanical properties showed high values of the elastic modulus (82.8 ± 3.6 GPa) and hardness (6.4 ± 1.2 GPa) and a minor deformation degree of 0.38% for the AO wires, although the bending strength exhibited the highest values for 3M. No corrosion was observed with a prolonged hydrolytic attack on the surface of any of the wires (0.0-0.5 National Bureau of Standards units). The highest nanomechanical properties and bending characteristics were observed for wires with higher NiTi precipitate contents, which were distributed differently in the alloy overall in the matrix. The nanoindentations sensed in different areas evidenced different mechanical properties for NiTi depending on its concentrations of Ti and enucleations.

Evaluation of titanium dioxide and tantalum pentoxide nanoparticles for coating NiTi archwires in orthodontics: An in vitro study

Background: This study aims to enhance the biocompatibility of Nickel–Titanium (NiTi) alloy by developing a new coating using titanium dioxide (TiO2) and titanium pentoxide (Ta2O5) through direct current (DC) reactive sputtering technology. Materials and methods: Two distinct coating materials, namely, TiO2 and Ta2O5, were used to fabricate NiTi orthodontic archwires with improved surface properties. TiO2 nanoparticles, with thickness ranging from 21.90 nm to 31.93 nm, were deposited onto NiTi alloy substrates through DC reactive sputtering deposition under different power conditions. Results: X-ray diffraction and field emission scanning electron microscopy validated the uniformity and morphology of the coatings. Immersion tests in simulated body fluid (SBF) revealed significant hydroxyapatite layer growth on TiO2-coated NiTi, especially at a sputtering power of 240 W. Reduced nickel ion release was observed on TiO2 nanoparticles with a thickness of 21.90 nm at 50 W sputtering power compared with 31.93 nm-thick nanoparticles at 240 W. Ta2O5 thin films were deposited on NiTi substrates through DC magnetron reactive sputtering at ~100 °C with a deposition power of 50 W. Structural and morphological analyses through optical microscopy and X-ray diffraction, atomic force microscopy, and scanning electron microscopy revealed the homogeneity and low roughness of the coatings. Biocompatibility assessments in artificial saliva and SBF solutions established that Ta2O5-coated NiTi alloys exhibited superior electrochemical behavior, enhanced corrosion resistance, and diminished Ni ion release compared with uncoated specimens. Conclusion: TiO2 and Ta2O5 coatings not only improved the biocompatibility of NiTi orthodontic archwires but also presented a promising path for advanced biomedical applications. These coatings have potential in improving the cellular behavior and performance of NiTi-based orthodontic devices.

Effect of different mouthwash solutions on the surface morphology, nanohardness and flexural modulus of nickel-titanium orthodontic wire.

This laboratory study aimed to evaluate the effect of different mouthwash solutions on the surface and mechanical properties of NiTi arch wire. This experimental study was conducted at the Department of Preventive Dental Sciences, College of Dentistry, Princess Nourah bint Abdulrahman University, Saudi Arabia from September 2023 to November 2023. A 30 mm NiTi wires in length with 0.017 × 0.022" in dimensions were selected and equally divided into four groups: Control (G0) group wires were immersed in distilled water (DW); G1 wires were immersed in antiseptic mouthwash; G2 wires were immersed in fluoridated mouthwash; and G3 wires were immersed in therapeutic mouthwash. Surface morphology, nanohardness, and flexural modulus were evaluated at 24-hours, four weeks, and eight weeks' time points. Data were statistically analyzed using a two-way analysis of variance (P<0.05). The arch wires immersed in DW showed insignificant effects on surface roughness, nanohardness, and flexural modulus at different time points. However, all the experimental groups showed a significant effect of time and immersion solutions on the said properties (P<0.05). At the end of eight weeks, G3 showed the highest surface roughness (0.346 ± 0.032 µm) and the lowest nanohardness (1.350 ± 0.412 GPa) and flexural modulus (3.960 ± 0.140 MPa) compared to other study groups. The efficiency of tooth realignment could be influenced by the detrimental influence of fluoride and hydrogen peroxide mouthwash solutions on superelastic NiTi arch wires.

Evaluation of surface roughness, cytotoxicity, and antibacterial effects of silver nanoparticle coating on copper nickel titanium orthodontic arch wires - in vitro study.

Surface roughness of arch wires directly impacts their corrosion behavior, friction resistance, and plaque accumulation, which may hinder tooth movement and lead to dental caries. The study aims to synthesize vanillin-mediated silver nanoparticles (AgNPs), characterize them, assess surface roughness and cytotoxicity of arch wires after silver nanoparticle coating, and test their antibacterial properties. Nine copper-nickel-titanium arch wires (CuNiTi) were cut into equal pieces. Three were sent for surface roughness assessment, three for cytotoxicity, and three for antibacterial testing. Dip coating of wires was done using the sol-gel thin film method. The surface roughness (Ra) before and after coating was evaluated using scanning electron microscopy and atomic force microscopy. Cytotoxicity testing was done with a (3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay using gingival fibroblasts. Statistical analysis was done using SPSS software. Antibacterial activity against S. mutans was tested using the Agar-well diffusion method. The CuNiTi wires were coated successfully, and the coating appeared homogeneous. The mean Ra after coating (297.3+/- 30.4 nm) was significantly less than that before coating (339.7+/-49.2 nm). AgNPs showed minimal cytotoxicity against human gingival fibroblasts at different concentrations. Optical microscopy showed over 90% viability between 12.5 and 100 µg/ml. At 100 µg/ml, only 80% of cells remained viable. AgNP coating is biocompatible at concentrations up to 75 µg/ml. There was a significant intergroup difference in the zone of inhibition (antibacterial activity) noted with higher values in noncoated wires. (P value <0.007). AgNPs coated on CuNiTi arch wires showed reduced surface roughness and minimal cytotoxic effects on human gingival cells and good antibacterial activity against S. mutans compared to noncoated arch wires.

The effect of different clinical recycling methods on load deflection properties of super-elastic and thermal nickel-titanium orthodontic arch wires: A comparative assessment.

Repeated clinical use of arch wires requires sterilization and may result in alteration of the properties of the wires as they get subjected to corrosion and cold working. Therefore, the present study aimed to assess the effects of different clinical recycling methods on the load-deflection properties of super-elastic and thermal nickel-titanium orthodontic arch wires. A total of 50 0.014" round nickel-titanium orthodontic wires [Group I: super-elastic nickel-titanium (n = 25) and Group II: thermal nickel-titanium wires (n = 25)] were tested for changes in their load deflection properties after three different recycling methods, that is, dry heat sterilization, autoclave, and cold sterilization. For each group, five wires as received from the manufacturer were taken as control (T0), and the rest of the 20 wires were placed intra-orally for a duration of one cycle of clinical use (T1). Five wires out of these were subjected to 3-point bending tests, and the rest of the wires were subjected to different recycling methods. Load deflection properties of recycled wires were measured with an Instron universal testing machine. The results were tabulated, and the data were analyzed by analysis of variance (ANOVA) with the Tukey post hoc test. Statistically, no significant difference was found in the super-elastic group between samples recycled by dry heat, autoclave, and cold sterilization when compared with as-received super-elastic NiTi up to 2.5 mm of deflection. A highly significant difference was found between as-received thermal NiTi group (83.51 ± 6.49 N/mm) and samples recycled by dry heat (53.73 ± 4.72 N/mm), autoclave (45.38 ± 4.37 N/mm), and cold sterilization (48.44 ± 3.12 N/mm) at 0.5 mm of deflection. Among thermal NiTi, any of the sterilization methods could opt at all deflections. For super-elastic NiTi, at higher deflections or in cases of crowding of more than 2.5 mm, cold sterilization should be the method of choice, whereas any sterilization method can be used at deflections less than 2.5 mm.

Efficiency of clear aligners with nickel titanium wires for treating mandibular incisor crowding.

Patients who are allergic to nickel, which is present in stainless steel brackets and wires, commonly utilise clear aligners. The objective of this research was to compare the management of mandibular incisor crowding with nickel titanium (NiTi) wires and clear aligners. A random division of forty participants into two groups of twenty samples each was made. Participants in group B received transparent aligners, whereas those in group A received NiTi arch wires. We assessed malocclusion using Little's irregularity index. A survey instrument was utilised to document the degree of discomfort. Patients were routinely recalled every one, two, and three months. The mean score for groups A and B was 2.86 mm and 2.88 mm at baseline, 1.71 mm and 1.52 mm at one month, 1.02 mm and 1.23 mm at two months, and 0.72 mm and 0.48 mm at three months, respectively. The difference wasn't that big (p > 0.05). In groups A and B, the mean change in Little's irregularity index score was 1.19 mm and 1.21 mm at one month, 0.55 mm and 0.51 mm at two months, and 0.26 mm and 0.45 mm at three months, respectively. The difference wasn't that big (p > 0.05). For groups A and B, the corresponding mean discomfort scores were 2.6 and 2.3 at baseline, 2.2 and 1.8 after one month, 1.6 and 1.5 at two months, and 1.1 and 0.9 at three months. Since p > 0.05, the difference was not significant. The results of this study showed that NiTi wires and clear aligners worked just as well to treat cases of mandibular anterior crowding.

Oxidized Ethylene Glycol/ZrO2-coated NiTi Orthodontic Arch Wires: Surface Characterization and Electrochemical and Corrosion Studies

Background: Orthodontic arch wires, typically made of Nickel Titanium (NiTi), are widely utilized in dental procedures for correcting teeth misalignment and jaw issues due to their favorable mechanical attributes and cost-effectiveness. However, these NiTi wires are prone to corrosion in the oral environment, leading to diminished mechanical stability, compromised aesthetics, and potential health concerns for patients. Objective: There is a growing demand to augment the corrosion resistance and stability of orthodontic wires. Hence, this study aimed to address these issues. Herein, zirconium dioxide (ZrO2) and oxidized ethylene glycol (OEG) films were deposited onto NiTi wires to improve the corrosion resistance and stability. Methods: NiTi wires were modified by a two-step process involving electrodeposition of ZrO2 and oxidized ethylene glycol (OEG) film. The surface characterizations of coated material (OEG/ZrO2/NiTi) were carried out by using Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), and Electron Microprobe Analysis (EMap) to confirm the elemental composition of the coated NiTi wire. Results: The OEG/ZrO2/NiTi wire exhibited a potentiodynamic polarization resistance of 547037 Ω and higher stability than the bare NiTi wire (396421 Ω). The corrosion rate for OEG/ZrO2/NiTi wire was found to be 0.040 mm/year, which was comparatively lower than a bare NiTi wire (0.069 mm/year). Due to the formation of OEG/ZrO2 film, NiTi wire became electrically insulative and showed a higher impedance than bare NiTi wire. Conclusion: The bilayer coating of ZrO2 and OEG has proven to significantly improve the corrosion resistance and stability of the wires. Thus, these materials can be considered for coating orthodontic arch wires with improved corrosion stability.

DNA fragmentation of lymphocytes and sperm cells induced by nickel released from orthodontic archwires: A preliminary study.

Orthodontic brackets and archwires placed intraorally are subject to corrosion, leading to the release of cytotoxic metal ions. The aim of this study was to determine whether the use of orthodontic NiTi archwires increases systemic Ni levels and cause alterations on the DNA of cells unrelated to the oral environment such as lymphocytes and sperm cells. Human urine, semen and blood samples were collected before (baseline) sham placement of orthodontic archwires and 15 and 30 days after placement. Lymphocytes and sperm cells cells were evaluated by comet assay. Ni concentration levels in urine increased significantly between baseline and 15 days (p<0.01) and 15 and 30 days of exposure (p<0.01). Progressive decrease in sperm viability and motility was observed between the sampling periods. Lymphocytes and sperm cells showed DNA fragmentation. The increase in systemic concentration of nickel induced structural damage in the DNA of lymphocytes and human sperm cells.

Biomechanical innovations in correcting severe malocclusions

The correction of severe malocclusions presents significant challenges in orthodontics due to the complexity and precision required for effective treatment. Recent biomechanical innovations have transformed the landscape of orthodontic care, offering more precise, efficient, and patient-friendly solutions. Advancements in orthodontic bracket systems, including the development of self-ligating brackets and heat-activated arch wires, have enhanced the control and comfort of tooth movements, reduced treatment times and improving patient outcomes. Temporary anchorage devices (TADs) have provided stable anchorage points, enabling complex tooth movements that were previously difficult to achieve. TADs have proven particularly effective in managing open bites and class II malocclusions, offering non-surgical alternatives for severe cases. The integration of digital technology in orthodontics, such as 3D imaging and computer-aided design/manufacturing (CAD/CAM), has further revolutionized treatment planning and execution. These technologies facilitate accurate diagnostics and the creation of customized orthodontic appliances, ensuring precise and predictable treatment outcomes. Clear aligner therapy, initially limited to simple cases, has advanced through the use of improved thermoplastic materials and digital customization, allowing for the treatment of more complex malocclusions. Innovative force application techniques, including the use of attachments and elastics, have expanded the capabilities of aligners, making them a versatile and effective alternative to traditional braces. Collectively, these biomechanical innovations have significantly improved the management of severe malocclusions, enhancing treatment efficiency, precision, and patient comfort. The ongoing development of these technologies promises to further advance the field of orthodontics, providing more effective and aesthetically pleasing solutions for patients with complex dental alignment issues.

The Effects of Air Abrasive Polishing on the Release of Iron Ions from Various Orthodontic Arch Wires (Stainless Steel and Nickel Titanium)

Orthodontic treatment with has been increasingly demanded. However, when using fixed appliances for orthodontic treatment, oral hygiene is compromised, and there is a higher chance of developing dental stains, plaque-related diseases, and corrosion-related problems. Air abrasive polishing had a superior effect over the conventional method in removing dental deposits, however, its effect on corrosion process was not investigated thoroughly in details. This study designed to assess the effects of air polishing onion release and surface micromorphology of stainless steel and Nickel titanium arch wires. A total of 288 ( stainless-steel , coated stainless steel , Nickel titanium and coated Nickel titanium rectangular arch wires ) of one brand ( The Ultimate Wire) ™ From IOS (International Orthodontic Services, Stafford, USA), (0.016 * 0.022 ) were subjected to varying air abrasion polishing periods (5, 10, and 20 seconds), after which they were immersed in artificial saliva with a pH of 6.75 and incubated at 37°C for 28 days. Ion release was measured using an atomic absorption spectrophotometer at 7 days, 14 days, and 28 days. The cumulative effect was then calculated. After polishing the chosen sample, corrosion and surface changes were evaluated using a scanning electron microscope (SEM). The significant difference between the analysed groups was found using an analysis of variance (ANOVA) and the LSD test, with a significance level of p 0.05. The results revealed that all types of arch wire showed a significant amount of release in the tested ions and the amounts of nickel and iron ions released was higher than chromium ion. Additionally, the longer the polishing time the higher the number of ions release that’s yields the level of significance, air abrasion polishing increased surface roughness and surface pits and crevices.It may be concluded that the air polishing method enhanced the amount of ion release to a subtoxic level and could be employed in adult patients with a lengthy time between visits.This study was performed to:1. Evaluate the effect of calcium carbonate airborne particles abrasion with different polishing times 5, 10 and 20 seconds on (Fe) ions release from orthodontic arch wires. 2. Assess the surface micromorphology of orthodontic arch wires after air polishing procedure.

Assessment of Mutans Streptococci Adhesion on Different Esthetic Coatings of Nickel-Titanium (Niti) Archwires: An In Vitro Study

Plaque and enamel demineralization can occur when orthodontic archwires are present in the oral cavity because they provide a unique surface for bacterial adhesion. Bacterial biofilm plays a major role in the development of complications such dental caries and periodontal disease. The purpose of the study was to examine the effect that an esthetic surface coating of NiTi archwires would have on the adherence of mutans streptococci. Material and method: three types of coated NiTi archwires (rhodium, gold and flexy blue) and one uncoated NiTi archwire with round cross section 0.016 inch were tested in the current study. Five pieces of each types of archwire were incubated in phosphate-buffered saline for two hours. Then, these wire segments were immersed for 5, 90, and 180 minutes with mutans streptococci suspension to conduct the bacterial adhesion assay. Result: there were statistically significant differences in the degree to which bacteria adhered to the various archwires at each time interval, with the level of adhesion being statistically highest on the uncoated NiTi wire and the level being statistically lowest on the gold-coated NiTi wire (p &lt; 0.05). The result showed that the highest bacterial adhesion in 180 min followed by 90 min and the lowest in 5 min. A positive correlation was detected between bacterial adhesion and incubation time. Conclusion: the esthetic surface coating were influence the biofilm adhesion on the archwires, gold coated significantly decrease mutans streptococci adhesion when compare with uncoated NiTi wire. Higher incubation time increased the number of bacterial adherence for all types of archwires.

Potential of Avocado Seed Extract (Pasea Americana) As A Corrosion Inhibitor Against Surface Roughness OF CUNITI Orthodontic WIRE

The surface roughness of orthodontic archwires is an essential factor that deter- mines the effectiveness of arch-guided tooth movement. CuNiTi-based wires are widely used in orthodontic treatment, but the oral environment can trigger corrosion of CuNiTi orthodontic wires. The tannin content in avocado seed extract can be used as a corrosion inhibitor through two working mechanisms, namely, forming a passive layer and an adsorption process. The aim of this research is to examine the effect of avocado seed extract as a corrosion inhibitor on the surface roughness of orthodontic CuNiTi wire. The as- retacngular 17 x 25 inch CuNiTi wire were taken in 4 group (1 control group soaked in artificial saliva and 3 treatment groups soaked in avocado seed extract ). Samples were immersed in avocado seed extract with concentrations of 1,5 g/L, 2 g/L and 2,5g/L for 7 days. For surface roughness was test Surface Roughness Average analysis. One way ANOVA test showed that there was a significant difference between the control group and all treatment groups in the surface roughness test with a value of p = 0.000. Post Hoc LSD test showed that there were no significant differences between treatment group 2 and treatment group 3 with a p value = 0.122. Providing avocado seed extract with tannin content at concentrations of 1.5 g/L and 2 g/L can reduce surface roughness on CuNiTi wire due to the corrosion process.

Aligners: review of their chemical components, recycling, mechanical properties and therapeutic needs - Part 1

The aligner is a thermoformed plastic device composed of various chemical components: polyurethane, polyethylene terephthalate glycol, polypropylene…All these plastics must be sufficiently resistant to abrasion and translucent for aesthetic purposes, but their solubility to salivary enzymes, insertion-disinsertion fatigue and recyclability vary according to material. From an orthodontic point of view, they must facilitate tooth movement. However, their behavior differs from that of orthodontic archwires: their Young's modulus, resilience and unloading curve are distinct, resulting in mechanical properties that fall significantly below the orthodontic requirements of multi-bracket systems. The aim of this article was to review the chemical composition, recycling and mechanical properties of aligners, and to put them into perspective with therapeutic indications. Literature data were approximated to orthodontic needs. Neither plastic nor direct printing can match the mechanical properties of our archwires or the procedures of a reliable vestibular multi-attachment appliance. Aligners remain an interesting tool in targeted indications.

Deep bite correction using auxiliary intrusion cantilevers with initial arch wires in adolescents

Deep bite correction using auxiliary intrusion cantilevers with initial arch wires in adolescents