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Materials (Basel, Switzerland) Mar 2022The aim of this study was to explore whether changes in the salivary pH influence mechanical properties, surface roughness, and ion release from NiTi archwires with...
The aim of this study was to explore whether changes in the salivary pH influence mechanical properties, surface roughness, and ion release from NiTi archwires with various surface coatings, and discuss the clinical significance of the findings. The uncoated, rhodium-coated, and nitrified NiTi wires were immersed into artificial saliva of different pH values (4.8, 5.1, 5.5, and 6.6). Released nickel and titanium ions were measured with inductively coupled plasma-optical emission spectroscopy at the end of 28 days. Atomic force microscopy was used to measure the arithmetic average surface roughness , the root-mean-square roughness , and the maximum height of the asperities . The nanoindentation hardness () and Young's modulus () measurements were performed. The change in the pH of artificial saliva is inversely proportional to the release of titanium from both coated and uncoated wires, and the release of nickel from uncoated wires. The surface roughness parameters of both coated and uncoated wires are unaffected by the change in the pH of artificial saliva. The change in the pH of saliva has minor influence on the hardness and Young's modulus of elasticity of both coated and uncoated wires. The concentration of released metal ions measured was below the recommended upper limit for daily intake; nevertheless, hypersensitivity effects cannot be excluded, even at lower concentrations and at low pH.
PubMed: 35329446
DOI: 10.3390/ma15061994 -
Journal of Dental Research, Dental... 2015Background and aims. This study compared the galvanic corrosion of orthodontic wires and brackets from various manufacturers following exposure to a fluoride mouthwash....
Background and aims. This study compared the galvanic corrosion of orthodontic wires and brackets from various manufacturers following exposure to a fluoride mouthwash. Materials and methods. This study was conducted on 24 lower central incisor 0.022" Roth brackets of four different commercially available brands (Dentaurum, American Orthodontics, ORJ, Shinye). These brackets along with stainless steel (SS) or nickel-titanium (NiTi) orthodontic wires (0.016", round) were immersed in Oral-B mouthwash containing 0.05% sodium fluoride for 28 days. The electric potential (EP) difference of each bracket-wire couple was measured with a Saturated Calomel Reference Electrode (Ag/AgCl saturated with KCl) via a voltmeter. The ions released in the electrolyte weremeasured with an atomic absorption spectrometer. All the specimens were assessed under a stereomicroscope and specimens with corrosion were analyzed with scanning electron microscopy (SEM). Data were analyzed using ANOVA. Results. The copper ions released from specimens with NiTi wire were greater than those of samples containing SS wire. ORJ brackets released more Cu ions than other samples. The Ni ions released from Shinye brackets were significantly more than those of other specimens (P < 0.05). Corrosion rate of brackets coupled with NiTi wires was higher than that of brackets coupled with SS wires. Light and electron microscopic observations showed greater corrosion of ORJ brackets. Conclusion. In fluoride mouthwash, Shinye and ORJ brackets exhibited greater corrosion than Dentaurum and American Orthodontics brackets. Stainless steel brackets used with NiTi wires showed greater corrosion and thus caution is recommended when using them.
PubMed: 26697148
DOI: 10.15171/joddd.2015.030 -
Materials (Basel, Switzerland) Oct 2021This study aimed to determine the kinetic frictional force (FF) of the recently produced TiNbTaZrO (Gummetal) orthodontic wire and compare it to the widely used wires of...
BACKGROUND
This study aimed to determine the kinetic frictional force (FF) of the recently produced TiNbTaZrO (Gummetal) orthodontic wire and compare it to the widely used wires of stainless steel (SS), nickel-titanium (NiTi), cobalt-chromium (CoCr) and titanium-molybdenum (TiMo) alloys.
METHODS
Five types of 0.016″ × 0.022″ wires were ligated with elastic ligatures to 0.018″ × 0.025″ SS brackets. The dynamic FFs between the brackets and ligated wires were measured utilizing a specialized tensile tester machine. Prior sample sizes for different archwires were conducted using power analysis for the general linear models. The existence of significant differences in FF between examined materials was initially confirmed by the one-way analysis of variance (ANOVA) with further evidence of pairwise differences by Tukey's Honest Significant Difference test.
RESULTS
The pairwise differences between means of kinetic FFs for NiTi, CoCr, and Gummetal wires were not statistically significant (adjusted -value > 0.05). Stainless steel alloy presented the lowest FF values significantly different from other groups (adjusted -value < 0.05). On the contrary, TiMo wires showed significantly greater FFs (adjusted -value < 0.05) than other alloys.
CONCLUSIONS
Gummetal orthodontic wire exhibits similar frictional resistance as NiTi and CoCr wires. Bendable TiNbTaZrO wire might be used for sliding mechanics due to its favorable frictional properties.
PubMed: 34771762
DOI: 10.3390/ma14216233 -
Journal of Orthodontic Science 2016The aim of this study was to investigate the effects exerted by the acidulated fluoride gel on stainless steel and nickel-titanium (Ni-Ti) orthodontic wires.
OBJECTIVES
The aim of this study was to investigate the effects exerted by the acidulated fluoride gel on stainless steel and nickel-titanium (Ni-Ti) orthodontic wires.
MATERIALS AND METHODS
Sixty stainless steel and Ni-Ti orthodontic archwires were distributed into forty archwires used for study and twenty for study. Fluoride was applied for 1 h in the experiment while it was applied for 5 min in the experiment. The friction resistance of all wires with ceramic brackets before/after topical fluoride application was measured using a universal testing machine at 1 min intervals of moving wire. Moreover, surface properties of the tested wires before/after fluoride application and before/after friction test were examined by a scanning electron microscope (SEM). Dunnett's -test was used to compare frictional resistance of as-received stainless steel wires and Ni-Ti wires to the wires treated by fluoride and ( < 0.05). Two-way ANOVA was used to compare the effect of fluoride application and type of wire on friction resistance and ( < 0.05).
RESULTS
Ni-Ti wires recorded significantly high friction resistance after fluoride application when compared to stainless steel wires , < 0.05. Fluoride application did not significantly affect the friction resistance of the tested wires , < 0.05. SEM observation revealed deterioration of the surface texture of the Ni-Ti wires after fluoride application and .
CONCLUSIONS
The fluoride application caused an increase in friction resistance of Ni-Ti wires when compared to stainless steel wires. and fluoride application caused deterioration in surface properties of Ni-Ti wires.
PubMed: 27843886
DOI: 10.4103/2278-0203.192114 -
Case Reports in Dentistry 2016Trauma may result in craze lines on the enamel surface, one or more fractured cusps of posterior teeth, cracked tooth syndrome, splitting of posterior teeth, and...
Trauma may result in craze lines on the enamel surface, one or more fractured cusps of posterior teeth, cracked tooth syndrome, splitting of posterior teeth, and vertical fracture of root. Out of these, management of some fractures is of great challenge and such teeth are generally recommended for extraction. Literature search reveals attempts to manage such fractures by full cast crown, orthodontic wires, and so forth, in which consideration was given to extracoronal splinting only. However, due to advancement in materials and technologies, intracoronal splinting can be achieved as well. In this case report, longitudinal fractures in tooth #27, tooth #37, and tooth #46 had occurred. In #27, fracture line was running mesiodistally involving the pulpal floor resulting in a split tooth. In teeth 37 and 46, fractures of the mesiobuccal cusp and mesiolingual cusp were observed, respectively. They were restored with cast gold inlay and full cast crown, respectively. Longitudinal fracture of 27 was treated with an innovative approach using intracanal reinforced composite with Ribbond, external reinforcement with an orthodontic band, and full cast metal crown to splint the split tooth.
PubMed: 27247808
DOI: 10.1155/2016/5083874 -
BMC Oral Health Jun 2023Controlling the 3D movement of central incisors during tooth extraction cases with clear aligners is important but challenging in invisible orthodontic treatment. This...
BACKGROUND
Controlling the 3D movement of central incisors during tooth extraction cases with clear aligners is important but challenging in invisible orthodontic treatment. This study aimed to explore the biomechanical effects of central incisors in tooth extraction cases with clear aligners under different power ridge design schemes and propose appropriate advice for orthodontic clinic.
METHODS
A series of Finite Element models was constructed to simulate anterior teeth retraction or no retraction with different power ridge designs. These models all consisted of maxillary dentition with extracted first premolars, alveolar bone, periodontal ligaments and clear aligner. And the biomechanical effects were analysed and compared in each model.
RESULTS
For the model of anterior teeth retraction without power ridge and for the model of anterior teeth no retraction with a single power ridge, the central incisors exhibited crown lingual inclination and relative extrusion. For the model of anterior teeth no retraction with double power ridges, the central incisors tended to have crown labial inclination and relative intrusion. For the model of anterior tooth retraction with double power ridges, the central incisors exhibited a similar trend to the first kind of model, but as the depth of the power ridge increased, there was a gradual decrease in crown retraction value and an increase in crown extrusion value. The simulated results showed that von-Mises stress concentration was observed in the cervical and apical regions of the periodontal ligaments of the central incisors. The clear aligner connection areas of adjacent teeth and power ridge areas also exhibited von-Mises stress concentration and the addition of power ridge caused the clear aligner to spread out on the labial and lingual sides.
CONCLUSIONS
The central incisors are prone to losing torque and extruding in tooth extraction cases. Double power ridges have a certain root torque effect when there are no auxiliary designs, but they still cannot rescue tooth inclination during tooth retraction period. For tooth translation, it may be a better clinical procedure to change the one-step aligner design to two-step process: tilting retraction and root control.
Topics: Humans; Incisor; Orthodontic Wires; Cuspid; Maxilla; Tooth Extraction; Orthodontic Appliances, Removable; Tooth Movement Techniques; Finite Element Analysis
PubMed: 37349701
DOI: 10.1186/s12903-023-03106-8 -
The Saudi Dental Journal Jul 2021Arch wire surface characteristics, especially surface roughness and topography, influence the coefficient of friction during sliding. The clinician should be familiar...
BACKGROUND
Arch wire surface characteristics, especially surface roughness and topography, influence the coefficient of friction during sliding. The clinician should be familiar with the properties of orthodontic appliances and materials that could result in high friction to maximize the efficiency of treatment. This study aimed to compare the static friction of orthodontic arch wire materials, including a newly introduced low-friction TMA, conventional TMA, and stainless steel arch wires, using an Instron universal testing machine and to evaluate their surface topographical features using a noncontact optical profilometer
METHODS
A total of 30 arch wire specimens were used, including 10 low-friction TMA (TMA-Low), 10 conventional TMA (TMA-C), and 10 stainless steel (SS), (Ormco, Orange, CA, USA) measuring 0.016 × 0.022 in. The static frictional force of each arch wire material was measured using the universal Instron machine. The surface topography was evaluated using a noncontact profilometer machine.
RESULTS
The static frictional resistance forces were highest in the TMA-C alloy group, and the value was statistically significant in comparison to the SS arch wire but not to the TMA-Low arch wire. The mean value of the static friction of the TMA-Low group was intermediate between the TMA-C and SS arch wires. However, this difference was statistically insignificant compared to the other two alloys. A surface roughness evaluation using a profilometer machine revealed that the highest mean of all three roughness parameters was found in the TMA-C group, followed by the TMA-Low and SS arch wires in descending order.
CONCLUSION
The static friction resistance forces and surface roughness values of the TMA-Low arch wire are comparable to those of TMA-C but are still considered inferior to those of the SS arch wire.
PubMed: 34194190
DOI: 10.1016/j.sdentj.2020.03.006 -
Scientific Reports Jun 2022This observational study evaluates three-dimensionally the relation between the root of maxillary canine and overlying labial cortical plate of bone during orthodontic... (Observational Study)
Observational Study
This observational study evaluates three-dimensionally the relation between the root of maxillary canine and overlying labial cortical plate of bone during orthodontic canine retraction. Eighty-four bilateral maxillary canines in 42 patients were retracted in the extraction space of first premolars, using conventional orthodontic NiTi retraction spring delivering 150gm. Three-dimensional evaluation at the cusp tip, root apex, and the overlying cortical bone was done based on Classification of Root/Cortical bone relation (CRCR) before and after canine retraction. 168 observations of the canines pre- and post-retraction showed a mean distal movement of the canine cusp tip of 3.78(± 2.05) mm, while the canine root apex was almost stationary. Scarcely, 5.4% of the canine roots and root apices persisted in the medullary bone during retraction, while 16.1% contacted the overlying cortical bone. Fenestration of the overlying cortical bone by the canine roots or root apices occurred in 78.6% of the sample. The unembellished intimacy between the canine root and apex to the overlying thick dense cortical bone might have the decelerating effect on the maxillary canine retraction. The natural bone plate labial to the maxillary canine root did not yield infront nor enlarge due to canine retraction, but else defeated the current orthodontic biomechanical implementation.
Topics: Cortical Bone; Cuspid; Humans; Maxilla; Orthodontic Wires; Tooth Movement Techniques
PubMed: 35739156
DOI: 10.1038/s41598-022-14663-3 -
The Angle Orthodontist Jan 2015To test for differences in loading and unloading forces delivered by six coated nickel-titanium wires and their noncoated equivalents. (Comparative Study)
Comparative Study
OBJECTIVE
To test for differences in loading and unloading forces delivered by six coated nickel-titanium wires and their noncoated equivalents.
MATERIALS AND METHODS
From six commercial companies, 0.016-inch diameter round and 0.016 × 0.022-inch rectangular cross-section nickel-titanium wires were procured "as is": Rocky Mountain Orthodontics (Denver, Colo), TP Orthodontics (La Porte, Ind), American Orthodontics (AO; Sheboygan, Wis), G&H (Franklin, Ind), Opal Orthodontics (South Jordan, Utah), and Forestadent USA (St Louis, Mo) (round only). The wires were evaluated using a three-point bending test based on the method in ISO Standard 15841.
RESULTS
No statistically significant differences (P > .05) in force values were found between coated and noncoated wires, listed by deflection in three-point bending, for these specific groups: 1 mm, TP round; 2 mm, TP round and G&H rectangular; 3 mm, G&H round and G&H rectangular; 2.5 mm,TP round and G&H rectangular; 1.5 mm, TP round, G&H round, G&H rectangular, and AO rectangular; and 0.5 mm, AO rectangular and G&H round.
CONCLUSION
Some manufacturers market esthetic wires delivering forces similar to the equivalent noncoated wires, when tested according to a standard three-point bend method.
Topics: Coated Materials, Biocompatible; Dental Alloys; Dental Stress Analysis; Esthetics, Dental; Humans; Materials Testing; Nickel; Orthodontic Wires; Pliability; Stress, Mechanical; Surface Properties; Titanium
PubMed: 24901067
DOI: 10.2319/092513-701.1 -
The Angle Orthodontist Sep 2021To examine the torque moment that occurs between esthetic brackets and bendable alloy (stainless steel [SS], titanium-molybdenum [Ti-Mo], and titanium-niobium [Ti-Nb])...
OBJECTIVES
To examine the torque moment that occurs between esthetic brackets and bendable alloy (stainless steel [SS], titanium-molybdenum [Ti-Mo], and titanium-niobium [Ti-Nb]) wires.
MATERIALS AND METHODS
This study examined ceramic (CR), zirconium oxide (ZC), polycarbonate (PC), and conventional metallic brackets (MT) (upper, 0.018-inch and 0.022-inch slots) combined with SS, Ti-Mo, and Ti-Nb wires using elastic module ligation. The torque moments delivered by various wire and bracket combinations were measured using a torque gauge apparatus. The wire torque angles at 5-40° were examined.
RESULTS
The torque value increased in the order of CR, ZC, MT, and PC brackets for both 0.018-inch and 0.022-inch slots. The fracture points of the CR and ZC brackets combined with SS and Ti-Mo wires were approximately more than 30° and 35°, respectively. No fracture points were detected in the combination of ZC brackets and Ti-Nb wires.
CONCLUSIONS
The current study identified the material characteristics of CR, ZR, and PC brackets during torque tooth movements. The present results demonstrate a characteristic combined effect between different esthetic brackets and bendable alloy wires.
Topics: Alloys; Dental Stress Analysis; Esthetics, Dental; Materials Testing; Orthodontic Appliance Design; Orthodontic Brackets; Orthodontic Wires; Stainless Steel; Titanium; Torque
PubMed: 33822872
DOI: 10.2319/081820-729.1