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 Evaluation and Comparison of Two Different Mouthwashes on Frictional Resistance Between Orthodontic Bracket and Archwire: An in Vitro Study

2019 ◽  
Vol 53 (2) ◽  
pp. 117-125
Author(s):  
Jayanti Choudhary ◽  
B Shashikumar ◽  
Anand K Patil
Keyword(s):  
Stainless Steel ◽  
Artificial Saliva ◽  
Steel Wire ◽  
Testing Machine ◽  
Frictional Resistance ◽  
Control Group ◽  
Tea Tree ◽  
Custom Made ◽  
Significant Difference

Aims: This study aimed to evaluate and compare the effect of tea tree oil (TTO) mouthwash and chlorhexidine (CHX) mouthwash on frictional resistance. Settings and Design: In vitro. Materials and Methods: In total, 60 extracted premolars were mounted on a custom-made acrylic fixture. These 60 premolars were randomly divided into 3 groups of 20 each, on which 0.022″ × 0.028″ slot MBT stainless steel brackets were bonded and 0.019″ × 0.025″ rectangular stainless steel wire was ligated with an elastomeric module. The 3 groups included a control group where the samples were immersed in artificial saliva and 2 experimental groups immersed in 0.2% CHX and TTO mouthwash, respectively, for 1.5 hours. Postimmersion static frictional resistance was evaluated on a universal testing machine at crosshead speed of 0.5 mm/min. Statistical Analysis Used: Tukey’s post hoc procedure. Results: This study showed a statistically significant difference in the frictional resistance between saliva and CHX groups and CHX and TTO groups ( P < .05). No statistically significant difference was observed between saliva and TTO groups ( P > .05). The frictional resistance was more in the CHX mouthwash group than in the TTO mouthwash group. Conclusions: Frictional resistance was lesser in the TTO mouthwash than in the CHX mouthwash. Based on this result, TTO mouthwash can be used instead of CHX mouthwash as an oral hygiene aid in patients with orthodontic treatments.

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 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 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 &lt; .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 Comparative Evaluation of Fracture Resistance of Endodontically Treated Teeth Restored with Resin Fiber Post and Stainless Steel Post: An In Vitro Study

2015 ◽  
Vol 03 (02) ◽  
pp. 080-084
Author(s):  
Vijay Singh ◽  
Poonam Bogra ◽  
Saurabh Gupta ◽  
Navneet Kukreja ◽  
Neha Gupta
Keyword(s):  
Stainless Steel ◽  
Fracture Resistance ◽  
Testing Machine ◽  
Compressive Force ◽  
Control Group ◽  
Fiber Post ◽  
Endodontically Treated Teeth ◽  
Group I ◽  
Significant Difference

AbstractFracture resistance of endodontically treated teeth restored with post. Aims: This study aims to compare the fracture resistance of endodontically treated teeth restored with resin fiber and stainless steel post. Commercially available prefabricated resin fiber post(Dentsply Maillefer Easy Post), prefabricated stainless steel post(Coltene/Whaledent Parapost) were used. Methods and Material: Forty five maxillary central incisors were obturated and divided into 3 groups: Control Group (Group I) without any post (n = 15), Resin Fiber Post Group (Group II) (n = 15) and Stainless Steel Post Group (Group III) (n = 15). In all Groups except control group, post space was prepared; a post was cemented, and a core build-up was provided. All the specimens were subjected to compressive force under a universal testing machine until fracture. Statistical analysis used: The results were analyzed using the variable analysis test (ANOVA). Results: One-way analysis of variance revealed significant difference among test groups. The control group demonstrated highest fracture resistance (925.2183 N), followed by the resin fiber post group (486.7265 N) and stainless steel post group (423.539N). Conclusions: Teeth restored with resin fiber post showed higher fracture resistance values than prefabricated stainless steel post.

scholarly journals Uji Biokompabilitas pada Implan Orthopedi Antara Implan Impor, Implan Lokal dari Material Impor, dan Prototipe Stainless Steel 316L dari Material Lokal

2019 ◽  
Vol 3 (1) ◽  
pp. 7
Author(s):  
Ferdiansyah Mahyudin ◽  
Heppy Chandra Waskita ◽  
Dwikora Novembri Utomo ◽  
Heri Suroto ◽  
Tri Wahyu Martanto
Keyword(s):  
Stainless Steel ◽  
Acute Toxicity ◽  
Mtt Assay ◽  
Orthopedic Implants ◽  
Fibrous Capsule ◽  
Cytotoxicity Test ◽  
Stainless Steel 316L ◽  
Medical Test ◽  
Significant Difference ◽  
One Way Anova

ABSTRACT  Demands of orthopedic implants are increasing in Indonesia, but its production are limited and still imported. Stainless steel, especially 316L is one of metal that is used commonly. This research evaluates biocompatibility of stainless steel 316L implant prototype, local implant manufactured using imported stainless steel, and imported stainless steel implant. Cytotoxicity test used mesenchymal human cell with MTT assay. Irritation test, acute toxicity/pyrogenicity test, and implantation test used 24 Wistar rats respectively which were assigned to 4 groups. We evaluate Draize score, weight and rectal temperature changes, and fibrous capsule ring thickness. Cytotoxicity test shows viable cell percentage in stainless steel 316L implant prototype, local implant, and imported implant are 83.7%, 87.5%, and 83.7% respectively. Comparison test using One Way ANOVA shows no significant difference between 3 groups (p>0.05). Iritation test results in 3 groups are grade 0 (no edema and no erythema). Acute toxicity/pyrogenicity test shows no statistically significant difference (p>0.05) among all groups. There is also no significant difference (p>0.05) of fibrous capsule ring thickness on 1 and 4 weeks after implantation. Based on ISO for medical test guide, stainless steel 316L implant prototype is safe and has similar biocompatibility test result compared to local and imported implant.Keywords                   : stainless steel 316L, biocompatibility, orthopaedic implantCorrespondence to    : [email protected] ABSTRAKKebutuhan implan orthopedi terus meningkat di Indonesia, namun produksinya terbatas dan sebagian besar masih impor dari luar negeri. Stainless steel, utama 316L adalah salah satu metal yang sering digunakan. Penelitian ini mengevaluasi biokompatibilitas dari prototipe implan stainless steel 316L, implan lokal yang diproduksi menggunakan stainless steel impor, dan implan stainless steel impor. Uji sitotoksisitas menggunakan sel mesenkim human dengan MTT assay. Uji iritasi, uji pirogenositas, dan uji implantasi menggunakan 24 tikus Wistar yang terbagi dalam 4 grup. Kami mengevaluasi skor Draize, perubahan berat dan temperatur rektal, dan ketebalan fibrous capsule ring. Uji sitotoksisitas menunjukkan persentase viabilitas sel pada prototipe stainless steel 316L, implan lokal, dan implan impor berturut-turut adalah 83,7%; 87,5%; dan 83,7%. Uji komparasi dengan One Way Anova tidak menunjukkan perbedaan signifikan diantara 3 grup (p>0,05). Hasil uji iritasi 3 grup menunjukkan grade 0 (tidak ada edema dan eritema). Uji pirogenositas tidak menunjukkan perbedaan signifikan pada semua grup (p>0,05). Tidak ada perbedaan signifikan (p>0,05) pula pada ketebalan fibrous capsule ring di minggu ke 1 dan 4 setelah implantasi. Berdasarkan ISO untuk pedoman uji di bidang medis, prototipe stainless steel 316L aman dan memiliki kesamaan hasil uji biokompatibilitas bila dibandingkan dengan implan lokal dan impor.Kata kunci              : stainless steel 316L, uji biokompatibilitas, implan orthopaediKorespondensi       : [email protected]

scholarly journals VEGF/Flk1 Mechanism is Involved in Roxarsone Promotion of Rat Endothelial Cell Growth and B16F10 Xenograft Tumor Angiogenesis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shihao Chen ◽  
Jinge Xu ◽  
Qianhan Wei ◽  
Zeting Zhao ◽  
Xin Chen ◽  
...  
Keyword(s):  
Cell Growth ◽  
Cell Viability ◽  
Vascular Endothelial Cells ◽  
Growth Promotion ◽  
Xenograft Model ◽  
Feed Additive ◽  
Vascular Endothelial ◽  
Mouse Xenograft Model ◽  
Significant Difference

AbstractThe potential angiogenic effect of roxarsone, a feed additive widely used to promote animal growth worldwide, was demonstrated recently. We explored the mechanism of vascular endothelial growth factor (VEGF) and its receptor (VEGFR) in roxarsone promotion of rat vascular endothelial cells (ECs) and B16F10 mouse xenografts. ECs were treated with 0.1–50 μM roxarsone or with roxarsone plus 10 ng/mL VEGF, VEGFR1 (Flt1), or VEGFR2 (Flk1) antibodies for 12–48 h to examine their role in cell growth promotion. Small interfering RNA (siRNA) targeting Vegf, Flt1, and Flk1 were transfected in the ECs, and we measured the expression level, cell proliferation, migration, and tube formation ability. The siRNA targeting Vegf or Flk1 were injected intratumorally in the B16F10 xenografts of mice that received 25 mg/kg roxarsone orally. Cell viability and VEGF expression following roxarsone treatment were significantly higher than that of the control (P < 0.05), peaking following treatment with 1.0 μM roxarsone. Compared to roxarsone alone, the VEGF antibody decreased cell promotion by roxarsone (P < 0.05), and the Flk1 antibody greatly reduced cell viability compared to the Flt1 antibody (P < 0.01). Roxarsone and Flk1 antibody co-treatment increased supernatant VEGF significantly, while cellular VEGF was obviously decreased (P < 0.01), whereas there was no significant difference following Flt1 antibody blockade. The siRNA against Vegf or Flk1 significantly attenuated the roxarsone promotion effects on EC proliferation, migration, and tube-like formation (P < 0.01), whereas the siRNA against Flt1 effected no obvious differences. Furthermore, the RNA interference significantly weakened the roxarsone-induced increase in xenograft weight and volume, and VEGF and Flk1 expression. Roxarsone promotion of rat EC growth, migration, and tube-like formation in vitro and of B16F10 mouse xenograft model tumor growth and angiogenesis involves a VEGF/Flk1 mechanism.

scholarly journals Prototype of a new tip developed to be coupled to dental light-curing units for optimizing bonding of orthodontic brackets and accessories

2013 ◽  
Vol 18 (6) ◽  
pp. 112-116
Author(s):  
Sergio Luiz Mota Júnior ◽  
Márcio José da Silva Campos ◽  
Marco Abdo Gravina ◽  
Marcelo Reis Fraga ◽  
Robert Willer Farinazzo Vitral
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Light Exposure ◽  
Orthodontic Brackets ◽  
Light Refraction ◽  
New Device ◽  
Halogen Light ◽  
Significant Difference ◽  
Light Curing

OBJECTIVE: development of a new device to be coupled to light-curing units for bonding orthodontic brackets and accessories, and test its efficacy in an in vitro mechanical trial. The inner surface of the device is mirrored and is based on physical concepts of light refraction and reflection. The main advantage of such device is the reduced clinical time needed for bonding and the low possibility of contamination during the process. METHODS: One hundred and twenty specimens were used for testing the shear bond strength of brackets bonded with the device. The Adhesive Remnant Index (ARI) was also determined. The sample was divided into 2 groups. In group 1 a halogen light-curing unit was used while in group 2 a led light-curing unit was used. Each group was then subdivided. In subgroups H1 and L1, a conventional light guide rod was used while in subgroups H2 and L2 bonding was performed with the mirrored device coupled to the tip of the guide light rod. RESULTS: The values obtained for the shear bond strength and the ARI in the subgroups were compared. Results showed that there was no statistically significant difference for the shear strength (p > 0.05) and the ARI (p > 0.05) between the subgroups. CONCLUSION: The tests of mechanical trials and the ARI analysis showed that the new device fulfilled the requirements for bonding orthodontic accessories, and that the time for bonding was reduced to half, being necessary only one light exposure.

T-614 inhibits human aortic adventitial fibroblast proliferation and promotes interleukin-8 production in vitro

Vascular ◽  
2019 ◽  
Vol 28 (3) ◽  
pp. 314-320
Author(s):  
Weiping Ci ◽  
Tian Wang ◽  
Taotao Li ◽  
Jin Wan
Keyword(s):  
Cell Viability ◽  
Vascular Wall ◽  
Underlying Mechanism ◽  
Interleukin 8 ◽  
Control Group ◽  
Survival Fraction ◽  
Tnf Α ◽  
Significant Difference ◽  
Factor Α

Objectives The effect and underlying mechanism of T-614 (iguratimod) on Takayasu’s arteritis (TA) are unknown. Here, we report the effects of T-614 on cell proliferation and interleukin-8 (IL-8) production in human aortic adventitial fibroblasts (HAAFs) in vitro and explore its initial benefit in terms of vascular wall inflammation and remodeling for patients with TA. Methods HAAFs were cultured with 0, 5, 50, 100, or 250 μg/ml T-614 in the absence or presence of tumor necrosis factor-α (TNF-α) in vitro. Cell viability was determined by a modified MTT assay. Supernatant IL-8 levels were measured by enzyme-linked immunosorbent assays. Results In the presence of TNF-α, compared to that in the control group, cell viability of HAAFs significantly decreased in the 50, 100, and 250 μg/ml T-614 treatment groups (OD value: P <  0.01, P <  0.001, P <  0.001, respectively; survival fraction (SF): P <  0.05, P <  0.001, P <  0.001, respectively). However, there was no significant difference in cell viability between TNF-α-stimulated and unstimulated groups at the same concentration of T-614. In the absence or presence of TNF-α, T-614 suppressed HAAF cell viability dose-dependently (OD value: r = −0.915, P =  0.000; r = −0.926, P =  0.000, respectively; SF: r = −0.897, P =  0.000; r = −0.885, P =  0.000, respectively). Compared to that in the control group, in the absence of TNF-α, IL-8 levels in the 5 and 100 μg/ml T-614-treated groups were significantly higher ( P <  0.05); in the presence of TNF-α, IL-8 levels in the 5, 50, and 100 μg/ml T-614-treated groups were significantly higher ( P <  0.001, P <  0.001, P <  0.01, respectively). Further, there was a negative correlation between supernatant IL-8 levels and T-614 concentration in groups stimulated with TNF-α ( r = −0.670, P =  0.000), but there was no significant correlation between these parameters in groups that were not stimulated with TNF-α. Conclusions In the absence or presence of TNF-α, T-614 can inhibit HAAF proliferation and promote IL-8 production in vitro; therefore, it could be used to prevent adventitial thickening of the aorta and improve vascular remodeling in inflammatory environments in vitro and might provide a new immunotherapeutic intervention for TA.

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