scholarly journals In Vitro Frictional Forces Generated by Three Different Ligation Methods

2008 ◽  
Vol 78 (5) ◽  
pp. 917-921 ◽  
Author(s):  
Paola Gandini ◽  
Linda Orsi ◽  
Chiara Bertoncini ◽  
Sarah Massironi ◽  
Lorenzo Franchi

Abstract Objective: To test the hypothesis that there is no difference between the frictional forces produced by a passive self-ligating bracket (SLB) in vitro and a conventional bracket (CB) used with two types of elastomeric ligatures. Materials and Method: The brackets, wires and ligation methods used in vitro were a passive SLB and a CB used with two types of elastomeric ligatures (conventional elastomeric ligature [CEL] and unconventional elastomeric ligatures [UEL]). The bracket ligation systems were tested with two types of wires (0.014″ super elastic nickel titanium wire and 0.019″ × 0.025″ stainless steel wire). Resistance to sliding of the bracket/wire/ligature systems was measured with an experimental model mounted on the crosshead of an Instron testing machine with a 10 N load cell. Each sample was tested 10 consecutive times under a dry state. Results: Frictional forces close to 0 g were recorded in all tests with SLB and in all tests with UEL on CB with both wire types. Resistance to sliding increased significantly (87–177 g) (P < .05) when CEL on CB was used with both wires. Conclusion: UELs may represent a valid alternative to passive SLBs for low-friction biomechanics.

2012 ◽  
Vol 17 (4) ◽  
pp. 51-56 ◽  
Author(s):  
Roberta Buzzoni ◽  
Carlos N. Elias ◽  
Daniel J. Fernandes ◽  
José Augusto M. Miguel

OBJECTIVE: The aim of this study was to assess resistance to sliding of stainless steel passive self-ligating brackets with 0° and 2.5° angulations and to compare them to active self-ligating brackets at zero angulation. The hypothesis to be tested was that passive self-ligating brackets produce lower frictional forces than active self-ligating brackets. METHODS: Twenty five 0.022 x 0.028-in slot maxillary canine brackets were divided into 5 groups of 5 brackets: Damon SL II (Ormco, CA, USA) self-ligating bracket and Gemini (3M/Unitek, CA, USA) conventional bracket with angulation of 0 and 2.5° and a group of Speed 2 (American Orthodontics, WI, USA) active clip self-ligating system with zero angulation. Twenty five segments of stainless steel 0.020-in archwire (TP Orthodontics, IN, USA) were tested and each bracket/wire interface was evaluated at 4 successive points during sliding. Overall, 100 frictional values were analyzed by parametric analysis of variance and Bonferroni tests. RESULTS AND CONCLUSION: Frictional tests were performed with an Emic DL 10000 testing machine (Emic, Brazil) with a load cell of one kilogram. Passive self-ligating brackets produced lower frictional forces than active self-ligating brackets (p < 0.01). Under angulation, brackets with a slide mechanism produced higher friction than the same brackets under zero angulation (p < 0.01). Nevertheless, the slide system under angulation produced smaller friction values than conventional brackets tied with elastomeric ligatures in 0° tests.


2014 ◽  
Vol 4 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Vinit Singh ◽  
Swati Acharya ◽  
Satyabrata Patnaik ◽  
Smruti Bhusan Nanda

Introduction: During sliding mechanics, frictional resistance is an important counterforce to orthodontic tooth movement; whichmust be controlled to allow application of light continuous forces.Objective: To investigate static and kinetic frictional resistance between three orthodontic brackets: ceramic, self-ligating, andstainless steel, and three 0.019×0.025” archwires: stainless steel, nickel-titanium, titanium-molybdenum.Materials & Method: The in vitro study compared the effects of stainless steel, nickel-titanium, and beta-titanium archwires onfrictional forces of three orthodontic bracket systems: ceramic, self-ligating, and stainless steel brackets. All brackets had 0.022”slots, and the wires were 0.019×0.025”. Friction was evaluated in a simulated half-arch fixed appliance on a testing machine. Thestatic and kinetic friction data were analyzed with 1-way analysis of variance (ANOVA) and post-hoc Duncan multiple rangetest.Result: Self-ligating (Damon) brackets generated significantly lower static and kinetic frictional forces than stainless steel (Gemini)and ceramic brackets (Clarity). Among the archwire materials, Beta-titanium showed the maximum amount of frictional forceand stainless steel archwires had the lowest frictional force.Conclusion: The static and kinetic frictional force for stainless steel bracket was lowest in every combination of wire.


2016 ◽  
Vol 6 (1) ◽  
pp. 19-23
Author(s):  
Amol Mhatre ◽  
VK Ravindranath ◽  
Sachin Doshi ◽  
Girish Karandikar ◽  
PS Vivek

ABSTRACT Aim The aim of this in vitro study was to investigate the efficiency of the new generation of elastomeric ligatures with innovative designs (SlideTM and AlastiKTM Easy-to-Tie) in reducing frictional resistance (FR) during sliding mechanics as compared with conventional ligatures. Materials and Methods Sixty ligature samples divided into four groups were used for the study. Group A: QuiK-StiK™ (3M Unitek, Monrovia, CA, USA), Group B: AlastiK™ Easy-to-Tie (3M Unitek, Monrovia, CA, USA), Group C: Slide™ (Leone, Firenze, Italy), and Group D: SS ligatures 0.010” (Libral Traders, New Delhi, India). Universal Testing Machine, Instron was used for measuring FR at the bracket-wire interface. Results There was statistically significant difference in FR among all the four groups of ligatures tested (p < 0.001). Slide ligatures produced the least amount of FR followed by SS ligatures, Easy-to-Tie, and QuiK-StiK in the increasing order of the FR values registered. Conclusion SlideTM ligatures may represent a valid alternative to passive self-ligating brackets when minimal amount of friction is desired. Angulation introduced into the elastomeric ligatures reduces the friction in comparison to conventional elastomeric ligatures. How to cite this article Vivek PS, Ravindranath VK, Karandikar G, Doshi S, Mhatre A, Sonawane M. Frictional Characteristics of the Newer Low-friction Elastomeric Ligatures. J Contemp Dent 2016;6(1):19-23.


2020 ◽  
pp. 146531252097240
Author(s):  
Fernanda de Souza Henkin ◽  
Luciane Macedo de Menezes ◽  
Berenice Anina Dedavid ◽  
Cátia Abdo Quintão

Objective: To compare the mechanical strength of joints made by conventional soldering with those made by alternative, more biocompatible, methods (spot, tungsten inert gas [TIG] and laser welding), and to compare the microstructural morphology of wires welded with these techniques. Design: In vitro, laboratory study. Methods: Forty stainless-steel wire segments with 0.8-mm diameter were joined by silver soldering, spot, laser and TIG welding. Ten specimens were produced for each one. Tensile strength test was performed 24 h after welding on the Emic DL2000™ universal testing machine, using a load cell of 1000 N with a crosshead speed of 10 mm/min. Results: The highest tensile strength mean values were obtained with silver soldering (532 N), next were laser (420 N), spot (301 N) and TIG (296 N) welding. Statistically significant differences were observed between the groups; the Dunn post-hoc test revealed differences between laser and spot welding ( p=0.046), laser and TIG ( p = 0.016), spot and silver ( p <0.001), and silver and TIG ( p <0.001). Conclusion: Laser welding strength is high, and comparable to silver welding. Spot and TIG techniques present comparable and significantly lower strengths. The four methods presented resistance values compatible with orthodontic use. The microstructural morphology is different for each technique. The association between the mechanical performance and the microstructure evaluation shows that laser presented the highest quality joint.


2016 ◽  
Vol 86 (5) ◽  
pp. 789-795 ◽  
Author(s):  
Roberto Rongo ◽  
Rosa Valletta ◽  
Rosaria Bucci ◽  
Virginia Rivieccio ◽  
Angela Galeotti ◽  
...  

ABSTRACT Objective:  To investigate the cytotoxicity of nickel-titanium (NiTi) esthetic orthodontic archwires with different surface coatings. Materials and Methods:  Three fully coated, tooth-colored NiTi wires (BioCosmetic, Titanol Cosmetic, EverWhite), two ion-implanted wires (TMA Purple, Sentalloy High Aesthetic), five uncoated NiTi wires (BioStarter, BioTorque, Titanol Superelastic, Memory Wire Superelastic, and Sentalloy), one β-titanium wire (TMA), and one stainless steel wire (Stainless Steel) were considered for this study. The wire samples were placed at 37°C in airtight test tubes containing Dulbecco’s Modified Eagle’s Medium (0.1 mg/mL) for 1, 7, 14, and 30 days. The cell viability of human gingival fibroblasts (HGFs) cultured with this medium was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Data were analyzed by a two-way analysis of variance (α  =  .05). Results:  The highest cytotoxic effect was reached on day 30 for all samples. The archwires exhibited a cytotoxicity on HGFs ranging from “none” to “slight,” with the exception of the BioTorque, which resulted in moderate cytotoxicity on day 30. Significant differences were found between esthetic archwires and their uncoated pairs only for BioCosmetic (P  =  .001) and EverWhite (P &lt; .001). Conclusions:  Under the experimental conditions, all of the NiTi esthetic archwires resulted in slight cytotoxicity, as did the respective uncoated wires. For this reason their clinical use may be considered to have similar risks to the uncoated archwires.


2020 ◽  
Vol 54 (3) ◽  
pp. 203-213
Author(s):  
Subrat Kumar Sahany ◽  
G. Sreejith Kumar

Background: An understanding of bracket slot–archwire interface is imperative for biomechanical effectiveness in orthodontic sliding mechanics and hence the aim of the study is to evaluate frictional properties of lingual self-ligating brackets comparing with conventional lingual and labial self-ligating brackets using three different archwire alloys in various environments. Materials and Methods: This in vitro study compared the frictional force of labial and lingual self-ligating and conventional lingual brackets with stainless steel, TMA, and Cr-Co alloy archwires of 0.017” × 0.025” dimension in dry and wet conditions. Frictional forces were evaluated in a simulated half arch fixed appliance using a testing machine. Static and kinetic friction were measured and analyzed by one-way analysis of variance (ANNOVA) test and post hoc Duncan multiple range test. The effects of brackets and archwires in dry and wet conditions were analyzed by three-way variance (ANNOVA) test. Result: The maximum frictional forces were observed with labial self-ligating brackets followed by lingual conventional brackets and the least by lingual self-ligating brackets. Of all the wires tested, TMA wires had the maximum frictional forces followed by Co-Cr and stainless steel. In both conditions, the values were non-significant with all bracket–wire combinations except with Co-Cr and TMA wires. Conclusions: Varied amount of frictional force was shown by the brackets and wires with highest by labial self-ligating bracket, followed by lingual conventional and lingual self-ligating brackets. TMA wires experienced higher friction followed by Co-Cr and stainless steel with minimum friction.


2013 ◽  
Vol 14 (3) ◽  
pp. 488-495 ◽  
Author(s):  
S Chidambaram ◽  
M Vijay ◽  
D Praveen Kumar Varma ◽  
K Baburam Reddy ◽  
D Ravindranath ◽  
...  

ABSTRACT Aim The aim of the study is to investigate the galvanic corrosion potential of metal injection molding (MIM) brackets to that of conventional brackets under similar in vitro conditions with nickel-titanium and copper nickel-titanium archwires. Materials and methods Twenty-five maxillary premolar MIM stainless steel brackets and 25 conventional stainless steel brackets and archwires, 0.16 inch, each 10 mm length, 25 nickeltitanium wires, 25 copper nickel-titanium wires were used. They were divided into four groups which had five samples each. Combination of MIM bracket with copper nickel-titanium wire, MIM bracket with nickel-titanium wire and conventional stainless steel brackets with copper nickel-titanium wire and conventional stainless steel brackets with nickel-titanium wires which later were suspended in 350 ml of 1 M lactic acid solution media. Galvanic corrosion potential of four groups were analyzed under similar in vitro conditions. Precorrosion and postcorrosion elemental composition of MIM and conventional stainless steel bracket by scanning electron microscope (SEM) with energy dispersive spectroscope (EDS) was done. Results MIM bracket showed decreased corrosion susceptibility than conventional bracket with copper nickeltitanium wire. Both MIM and conventional bracket showed similar corrosion resistance potential in association with nickel-titanium archwires. It seems that both brackets are more compatible with copper nickel-titanium archwires regarding the decrease in the consequences of galvanic reaction. The EDS analysis showed that the MIM brackets with copper nickel-titanium wires released less metal ions than conventional bracket with copper nickeltitanium wires. Conclusion MIM brackets showed decreased corrosion susceptibility, copper nickel-titanium archwires are compatible with both the brackets than nickel-titanium archwires. Clinical significance Clinically MIM and conventional brackets behaved more or less similarly in terms of corrosion resistance. In order to decrease the corrosion potential of MIM brackets, more precise manufacturing technique should be improved to get a more smoother surface finish. How to cite this article Varma DPK, Chidambaram S, Reddy KB, Vijay M, Ravindranath D, Prasad MR. Comparison of Galvanic Corrosion Potential of Metal Injection Molded Brackets to that of Conventional Metal Brackets with Nickel-Titanium and Copper Nickel-Titanium Archwire Combinations. J Contemp Dent Pract 2013;14(3):488-495.


2014 ◽  
Vol 1025-1026 ◽  
pp. 385-390
Author(s):  
Niwat Anuwongnukroh ◽  
Surachai Dechkunakorn ◽  
Jirawat Arunakol ◽  
Wassana Wichai

One of the problems that often occurred during orthodontic treatment is bracket failure. This is usually the result either of the patient’s accidentally, applying inappropriate forces to the bracket or of a poor bonding technique. Thus, a significant number of teeth have to be rebonded in an orthodontic practice. Objective: The aim of this study was to evaluate the in vitro initial repeated shear bond strength of the three adhesive systems at two and five minutes after placement of a bracket. Materials and Methods: The three bonding agent adhesives are System1+, Rely-a-bond, Unite. Two hundred and forty human premolar teeth were divided into two groups, a control and an experimental group. Each group was further divided into three subgroups for bonding brackets with the three different adhesives. Only the teeth in the experimental group were sequentially bonded and debonded two times with the same adhesive. The teeth in control and experimental groups were tested for shear bond strength (at two and five minutes after the bracket was bonded) with an Instron testing machine. Results: The studies were found that : (1) there were differences between the shear bond strength of each adhesive in the control and experimental group. Unite had the highest shear bond strength followed by Rely-a-bond and System1+ at two minutes and five minutes, (2) the experiment group ( rebonded brackets) had higher shear bond strength than control group and Unite had in significant difference (p<0.05) of initial repeated bond strength with System1+ and Rely-a-bond at two minutes and five minutes and (3) there were mostly significant difference (p<0.05) between repeated shear bond strength at two minutes and repeated shear bond strength at five minutes. Conclusion: There were significant difference of the initial repeated shear bond strength of each adhesive. The orthodontists should be aware of applying force for tooth movement into the repeated bonding brackets.


2019 ◽  
Vol 53 (2) ◽  
pp. 117-125
Author(s):  
Jayanti Choudhary ◽  
B Shashikumar ◽  
Anand K Patil

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.


2007 ◽  
Vol 32 (4) ◽  
pp. 377-381 ◽  
Author(s):  
Y. I. KULIKOV ◽  
S. DODD ◽  
S. GHEDUZZI ◽  
A. W. MILES ◽  
G. E. B. GIDDINS

A new spiral linking technique for tendon repair in which one end of the tendon is spiralled around the other end has been developed. Using pig trotter extensor tendons, the Pulvertaft weave technique was compared with this new technique. Twenty-five repairs using each technique were tested by tensile loading with an Instron testing machine. The spiral linking technique matched the strength of Pulvertaft method: the mean peak loads were 102 and 105 N, respectively. The Pulvertaft weave was stiffer than the spiral linking technique: mean stiffness of 11.1 and 6.7 N/mm, respectively. The spiral linking technique also absorbed considerably more energy: energy absorbed prior to failure to 90% of peak load, 1.75 and 1.13 kN mm, respectively. In conclusion, the spiral linking technique appears as strong as the Pulvertaft weave and we believe it is easier to perform.


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