scholarly journals Chromium Release from New Stainless Steel, Recycled and Nickel-free Orthodontic Brackets

2009 ◽  
Vol 79 (2) ◽  
pp. 361-367 ◽  
Author(s):  
Maria Francesca Sfondrini ◽  
Vittorio Cacciafesta ◽  
Elena Maffia ◽  
Sarah Massironi ◽  
Andrea Scribante ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Repeated Measures ◽  
Inductively Coupled Plasma ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Atomic Emission ◽  
Orthodontic Brackets ◽  
Time Interval ◽  
Chromium Release

Abstract Objective: To test the hypothesis that there is no difference in the amounts of chromium released from new stainless steel brackets, recycled stainless steel brackets, and nickel-free (Ni-free) orthodontic brackets. Materials and Methods: This in vitro study was performed using a classic batch procedure by immersion of the samples in artificial saliva at various acidities (pH 4.2, 6.5, and 7.6) over an extended time interval (t1 = 0.25 h, t2 = 1 h, t3 = 24 h, t4 = 48 h, t5 = 120 h). The amount of chromium release was determined using an atomic absorption spectrophotometer and an inductively coupled plasma atomic emission spectrometer. Statistical analysis included a linear regression model for repeated measures, with calculation of Huber-White robust standard errors to account for intrabracket correlation of data. For post hoc comparisons the Bonferroni correction was applied. Results: The greatest amount of chromium was released from new stainless steel brackets (0.52 ± 1.083 μg/g), whereas the recycled brackets released 0.27 ± 0.38 μg/g. The smallest release was measured with Ni-free brackets (0.21 ± 0.51 μg/g). The difference between recycled brackets and Ni-free brackets was not statistically significant (P = .13). For all brackets, the greatest release (P = .000) was measured at pH 4.2, and a significant increase was reported between all time intervals (P < .002). Conclusion: The hypothesis is rejected, but the amount of chromium released in all test solutions was well below the daily dietary intake level.

scholarly journals Evaluation of degradation of force of esthetic elastomeric chains

2019 ◽  
Vol 48 ◽  
Author(s):  
Mayra Teixeira Cortat LUCINDO ◽  
Diego Patrik Alves CARNEIRO ◽  
Felipe Alexandre de SOUZA ◽  
Américo Bortolazzo CORRER ◽  
Heloisa Cristina VALDRIGHI
Keyword(s):  
Repeated Measures ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Time Interval ◽  
Test Machine ◽  
Reduction In Force ◽  
Original Length ◽  
The Aesthetic ◽  
Elastomeric Chains

Abstract Introduction Elastomers are considered important allies to orthodontic treatment and due to the aesthetic demand, aesthetic elastomers are increasingly used in adult patients. Objective The aim of this experimental in vitro study was to evaluate the degradation of force of esthetic elastomeric chains, of three different sizes: short, medium and long. Material and method For evaluating the degradation of force, 90 elastomeric chain segments were used, divided into 9 Groups (n=10), as follows: Morelli short elastomer, Morelli medium, Morelli long, Orthometric short, Orthometric medium, Orthometric long, American Orthodontic short, American Orthodontic medium and American Orthodontic long. Acrylic plates with pins were used to provide stretching of the elastomeric chains. The initial stretching force of the elastomeric chain was 150 grams, measured by a tensiometer. After this, they were prestretched to 50% of their original length, measured in an Instron 4411 Universal test machine, and placed on the seating pin on the plate. The plate was immersed in artificial saliva at 37 °C in a plastic receptacle, and removed for measurement after a time interval of 21 days. For statistical analysis, the methodology of mixed models for repeated measures in time and Tukey-Kramer test were used. Degradation of the forces was analyzed by 2-way analysis of variance (ANOVA) and the Tukey test. Result All the elastomeric chains showed statistically significant reduction in force (p<0.05). The American Orthodontic elastomeric chains showed higher reduction in force values, irrespective of the elastic size (p<0.05). Conclusion The three commercial brands studied underwent significant reduction in the quantity of force released; the American Orthodontic brand of elastomer showed the highest value of degradation in force.

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

2011 ◽  
Vol 12 (2) ◽  
pp. 91-99 ◽  
Author(s):  
Avinash Kumar ◽  
Nadeem Husain
Keyword(s):  
Stainless Steel ◽  
Frictional Force ◽  
Artificial Saliva ◽  
Steel Wire ◽  
Testing Machine ◽  
In Vitro Study ◽  
Frictional Resistance ◽  
Orthodontic Brackets ◽  
Wet Condition

ABSTRACT Aim The purpose of this investigation was to determine the kinetic frictional resistance offered by stainless steel and Titanium bracket used in combination with rectangular stainless steel wire during in vitro translatory displacement of brackets. Materials and methods In this study. Brackets: (All brackets used had a torque of – 7° and an angulation of 0°): (1) Dynalock (Unitek) 0.018” slot, 3.3 mm bracket width, (2) Mini Uni-Twin (Unitek) 0.018” slot, 1.6 mm bracket width, (3) Ultra-Minitrim (Dentaurum) 0.022” slot 3.3 mm bracket width, (4) Titanium (Dentaurum) 0.022” slot, 3.3 mm bracket width. WIRES: (1) 0.016 × 0.022” stainless steel (Dentaurum), (2) 0.017 × 0.025’'stainless steel (Unitek), (3) 0.018 × 0.025” stainless steel (Dentaurum), elastomeric modules (Ortho Organisers), 0. 009” stainless steel ligature wires, hooks made of 0.021 × 0.025” stainless steel wires, super glue to bond the hooks to the base of the bracket, acetone to condition the bracket and wires before testing and artificial saliva. Brackets were moved along the wire by means of an Instron universal testing machine (1101) and forces were measured by a load cell. All values were recorded in Newtons and then converted into gms (1N-102 gm). 200 gm was then subtracted from these values to find out the frictional force for each archwire/bracket combination. For each archwire/ bracket combination three readings were taken under wet and dry condition and also with stainless steel ligature and elastomeric modules separately. Results The results showed that narrow brackets generated more friction than wider brackets. Frictional force was directly proportional to wire dimension. Titanium brackets generated more friction than stainless steel brackets. Archwire and bracket ligated with elastomeric module generated more friction than when ligated with stainless steel ligature wire. Frictional forces in the wet condition were greater than in the dry condition for all archwire to bracket combinations. Conclusion Frictional force was seen to be inversely proportional to bracket width, frictional force was inversely proportional to bracket width, and in the wet condition were greater than in the dry condition for all archwire to bracket combinations. Clinical significance This study of friction is its role in lessening the force actually received by a tooth from an active component such as a spring, loop or elastic. Hence greater applied force is needed to move a tooth with a bracket archwire combination demonstrating high magnitudes of friction compared with one with a low frictional value. How to cite this article Husain N, Kumar A. Frictional Resistance between Orthodontic Brackets and Archwire: An in vitro Study. J Contemp Dent Pract 2011;12(2):91-99.

scholarly journals Metals and Metalloids Release from Orthodontic Elastomeric and Stainless Steel Ligatures: In Vitro Risk Assessment of Human Exposure

2019 ◽  
Vol 196 (2) ◽  
pp. 646-653 ◽  
Author(s):  
Aneta Olszewska ◽  
Anetta Hanć ◽  
Danuta Barałkiewicz ◽  
Piotr Rzymski
Keyword(s):  
Stainless Steel ◽  
Inductively Coupled Plasma ◽  
Human Exposure ◽  
Orthodontic Treatment ◽  
In Vitro Study ◽  
Human Saliva ◽  
Metal Exposure ◽  
Monthly Basis ◽  
Metal Levels

Abstract Elastomeric ligatures are increasingly used as a part of esthetic orthodontic treatment, particularly in children. The aim of the present study was to experimentally test whether these appliances may contribute to exposure to toxic elements. In the present study, elastomeric ligatures (ELs) were incubated in artificial human saliva for 1 month (a typical period of their use) and the release of 21 metals (Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mg, Mo, Ni, Pb, Rb, Tl, Ti, Sb, Sr, Sn, Zn, U, V) and 2 metalloids (As and Ge) was studied using inductively coupled plasma–mass spectrometry. For comparison, stainless steel ligatures (SLs) were incubated for 1, 3, and 6 months (since sometimes their use is prolonged) under similar conditions. The determined metal levels were compared to the corresponding safety limits for human exposure. During 1 month, the ELs released Cd, Co, Cr, Mn, Ni, and Sn at total mean ± SD level of 0.31 ± 0.09, 0.98 ± 0.30, 3.96 ± 1.31, 14.7 ± 8.5, 13.8 ± 4.8, and 49.5 ± 27.7 μg, respectively. Other elements were always below the detection limits. In case of SL, the release of Co, Cr, Fe, Ni, Mn, and Sn was observed, and the determined values increased over the studied period. After 6 months, their total mean ± SD levels amounted to 28.6 ± 0.2, 21.7 ± 0.2, 623.5 ± 3.0, 1152.7 ± 1.8, 5.5 ± 0.3, and 22.6 ± 0.2 μg, respectively. The released metal levels from both ligature types were always below safety limits. The release of Ni from SL during 6 months would constitute 5.0 and 11.5% of tolerable intake in adults and children, respectively. The results of this in vitro study highlight that the use of ligatures in orthodontic treatment can be considered safe in terms of metal exposure although elastic ligatures replaced on a monthly basis appear to be advantageous in comparison to the prolonged use of stainless steel appliances.

scholarly journals CYTOTOXICITY OF IONS RELEASED FROM 17-4 PRECIPITATION HARDENING STAINLESS STEEL ORTHODONTIC BRACKETS IN ARTIFICIAL SALIVA

2018 ◽  
Vol 9 ◽  
pp. 71
Author(s):  
Tjokro Prasetyadi ◽  
Bambang Irawan ◽  
Miesje Karmiati Purwanegara ◽  
Bambang Suharno ◽  
Sugeng Supriadi
Keyword(s):  
Stainless Steel ◽  
Cell Viability ◽  
Precipitation Hardening ◽  
Artificial Saliva ◽  
Nickel Content ◽  
Orthodontic Brackets ◽  
Assay Method ◽  
Cytotoxicity Test ◽  
Significant Difference

Objective: 17-4 precipitation hardening (PH) stainless steel has a low nickel content, which can reduce the risk of allergic reactions. It also has good mechanical properties against the stress caused by the archwire slot brackets in orthodontic treatments. The main focus of this study to evaluate the metal ions released into artificial saliva from different orthodontic brackets with the same 17-4 PH stainless steel and to examine the in vitro cytotoxicity of the metal.Methods: Material properties were analyzed by energy dispersive spectroscopy. The 3-(4,5-dimethylthiazol-2-y1)2,5-diphenyltetrazolium bromide (MTT) assay method was used to examine the cytotoxicity of Gemini and Synergy brackets.Results: The cytotoxicity test on all the orthodontic brackets showed a mean cell viability value above 80% in each immersion group, which means that this material is not cytotoxic to the human immortalized keratinocyte cell line.Conclusions: The results showed cell viability in the extracts of both groups of brackets, and there was no statistically significant difference between the groups (p>0.05).

scholarly journals Coated stainless steel archwires' discoloration measured by computerized system (An in-vitro study)

2020 ◽  
Vol 32 (4) ◽  
pp. 1-4
Author(s):  
Abeer B Mahmood
Keyword(s):  
Stainless Steel ◽  
Color Change ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Chemical Compositions ◽  
Color Changes ◽  
The Aesthetic ◽  
Post Hoc ◽  
Computerized System

Background: Aesthetic archwires are used to overcome the aesthetic problems of stainless steel wires but the color of the coating layer can be changed with time when exposed to oral environments. The aim of this study was to evaluate the degree of color change of different aesthetic archwires from different companies under different coloring solutions. Materials and Methods: One hundred fifty samples of coated archwires from three companies (Highland, G&H and Dany) were immersed in 5 solutions (artificial saliva, turmeric, tea, coffee and Miranda) to evaluate the degree of color changes after 7, 14 and 21 days using visible spectrophotometer. Data were collected and analyzed using one way ANOVA and post hoc Tukey’s tests. Results: Turmeric solution caused high color change than other solutions. Aesthetic archwires from Highland company showed the highest degree of color change than archwires from other companies. Conclusions: Turmeric solution produced more discoloration than other solutions and the effects of these solutions are related to different chemical compositions of those solutions.

scholarly journals A Comparative Evaluation of Static Frictional Resistance Using Various Methods of Ligation at Different Time Intervals: An In Vitro Study

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Amanpreet Singh Natt ◽  
Amandeep Kaur Sekhon ◽  
Sudhir Munjal ◽  
Rohit Duggal ◽  
Anup Holla ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Frictional Resistance ◽  
Static Friction ◽  
Significant Difference ◽  
Dry Conditions ◽  
The Mean ◽  
Time Periods

Aim. To compare and evaluate the static frictional resistance offered by the four different types of ligation methods in both dry and wet conditions and at different durations when immersed in artificial saliva.Material and Methods. Alastik Easy to Tie modules, Super Slick Mini Stix elastomeric modules, Power “O” modules, and 0.009″Stainless Steel ligatures were used to compare the static friction using maxillary canine and premolar Preadjusted Edgewise brackets with 0.022″× 0.028″slot and 0.019″× 0.025″stainless steel wires.Results. The mean frictional resistance for Alastik modules was the lowest and that of Stainless Steel ligatures was found to be highest among the four groups compared and the difference among the four groups was statistically significant (P<0.005). The mean static frictional resistance in all groups under dry conditions was lower than that under wet conditions. No statistical significant differences were found when the groups were compared at different time periods of immersion in artificial saliva.Conclusion. This study concludes that the Alastik modules showed the lowest mean static frictional forces compared to any other ligation method, though no significant difference was found for different time periods of immersion in the artificial saliva.

scholarly journals Comparing the Effectiveness of Different Dentinal Desensitizing Agents: In Vitro Study

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Mohideen S. Farook ◽  
Okba Mahmoud ◽  
Maysara Adnan Ibrahim ◽  
Marwah Berkathullah
Keyword(s):  
Repeated Measures ◽  
Morphological Changes ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Fluid Filtration ◽  
Formula Group ◽  
Desensitizing Agents ◽  
Edx Analyses ◽  
Group 2

Objectives. To evaluate the in vitro effectiveness of desensitizing agents in reducing dentine permeability. Methods. The efficacy of desensitizing agents in reducing dentine permeability by occluding dentine tubules was evaluated using a fluid filtration device that conducts at 100 cmH2O (1.4 psi) pressure, and SEM/EDX analyses were evaluated and compared. Forty-two dentine discs ( n = 42 ) of 1 ± 0.2   mm width were obtained from caries-free permanent human molars. Thirty dentine discs ( n = 30 ) were randomly divided into 3 groups ( n = 10 ): Group 1: 2.7% wt. monopotassium-monohydrogen oxalate (Mp-Mh oxalate), Group 2: RMGI XT VAR, and Group 3: LIQ SiO2. Dentine permeability was measured following treatment application after 10 minutes, storage in artificial saliva after 10 minutes and 7 days, and citric acid challenge for 3 minutes. Data were analysed with a repeated measures ANOVA test. Dentine discs ( n = 12 ) were used for SEM/EDX analyses to acquire data on morphological changes on dentine surface and its mineral content after different stages of treatment. Results. Desensitizing agents’ application on the demineralized dentine discs exhibited significant reduction of permeability compared to its maximum acid permeability values. Mp-Mh oxalate showed a significant reduction in dentine permeability ( p < 0.05 ) when compared to RMGI XT VAR and LIQ SiO2. On SEM/EDX analysis, all the agents formed mineral precipitates that occluded the dentine tubules. Conclusions. 2.7% wt. monopotassium-monohydrogen oxalate was significantly effective in reducing dentine permeability compared to RMGI XT VAR and LIQ SiO2.

scholarly journals An In-Vitro Evaluation of Microbial Adhesion on Different Types of Orthodontic Brackets

2021 ◽  
Author(s):  
Vedant Patni ◽  
Kuldeep Dmello ◽  
Jitesh Wadhwa ◽  
Mora Sathi Rami Reddy ◽  
Atul Singh
Keyword(s):  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Artificial Saliva ◽  
Bacterial Species ◽  
Brain Heart Infusion ◽  
In Vitro Study ◽  
The Self ◽  
Orthodontic Brackets ◽  
Ceramic Brackets

Introduction: Information regarding the adhesion of bacterial species and plaque accumulation to bracket material is limited. Adequate information is needed in order to offer patients orthodontic treatment without significantly increasing their risk of developing white spots, caries, or gingival inflammation. Aim: To determine the levels of the caries-inducing S. mutans species on metallic, self-ligating and ceramic brackets and to compare the total bacterial counts and counts of species present on these bracket materials. Materials and Methods: By means of an in-vitro study, six commercially available bracket systems {3M Gemini (A), American Ortho (B), Ormco (C), Begg (D), Ceramic (E) and Self-ligating (F)} were compared. The brackets were bonded in the cell well culture plate and the agar plates were prepared. Brain heart infusion medium including bacteria and artificial saliva was introduced to each bracket system containing 10 premolar brackets and were incubated. After 72 hours, the adherent bacteria were then detached by sonication and the Colony-Forming Units (CFU) of Streptococcus mutans were calculated on each bracket and were analysed using Statistical Package for the Social Sciences (SPSS) software version 17.0 for Windows. Results: Between the different bracket types, significant differences were found in terms of biofilm formation. The Begg brackets showed the least bacterial adhesion and the self-ligating brackets showed the highest bacterial adhesion and was statistically significant among all the groups (p<0.05). Ceramic brackets also showed a higher bacterial adhesion after the self-ligating brackets. Among the three groups of metallic brackets, 3M brackets showed the least bacterial adhesion but was statistically insignificant (p>0.05). Conclusion: Different orthodontic brackets serve as different loci for biofilm formation showing that the Begg brackets are the most hygienic among all the brackets taken in this study.

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