Elastomeric Ligatures Research Articles

Residents' journal review

Residents' journal review

Initial Tensile and Residual Forces of Pigmented Elastomeric Ligatures from Various Brands

This study aimed to investigate the initial tensile and residual forces of pigmented elastomeric ligatures (clear, pink, and metallic) from three commercial brands – Brand 1 (USA), Brand 2 (USA), and Brand 3(China). Twelve elastomeric ligatures of each brand and color were evaluated for initial tensile and residual forces after stretching for 28 days at 37°C by a Universal Testing Machine. The results showed that the highest initial tensile force was 14.78 N, 20.71 N, and 15.1 N for the metallic color of Brand-1, pink color of Brand -2, and metallic color of Brand -3, respectively. There were significant (p<0.05) differences in the initial tensile force of each brand, except clear and metallic color of Brand-1 & 3 and pink color of Brand-2 & 3. Similarly, among the pigmented ligatures from each brand, significant (p<0.05) differences were observed in the initial tensile force, except metallic color of Brand-1 & 3. Brand-3 had the highest residual force after 28 days, whereas the loss of force was 80-90% in Brand-1 & 2 and 20-30% in Brand-3. There were also significant (p<0.05) differences in the residual forces in each color and brand, except metallic color of Brand-1. In conclusion, there were significant differences in the initial tensile and residual forces among the three pigmented elastomeric ligatures of the three commercial brands.

Assessment of the Color Stability of Clear Elastomeric Ligatures : In Vivo Study

Assessment of the Color Stability of Clear Elastomeric Ligatures : In Vivo Study

Force level of small diameter nickel-titanium orthodontic wires ligated with different methods

BackgroundThe aim of this study was to compare the deflection force in conventional and thermally activated nickel-titanium (NiTi) wires in passive (Damon Q) and active (Bioquick) self-ligating brackets (SLB) and in conventional brackets (CB) tied by two different methods: elastomeric ligature (EL) and metal ligature (ML).MethodsTwo wire diameters (0.014 and 0.016 in.) and 10 specimens per group were used. The specimens were assembled in a clinical simulation device and tested in an Instron Universal Testing Machine, with a load cell of 10 N. For the testing procedures, the acrylic block representative of the right maxillary central incisor was palatally moved, with readings of the force at 0.5, 1, 2, and 3 mm, at a constant speed of 2 mm/min and temperature of 36.5 °C.ResultsThe conventional NiTi released higher forces than the thermally activated NiTi archwires in large deflections. In general, the SLB showed lower forces, while the ML had higher forces, with both showing a similar force release behavior, constantly decreasing as the deflection decreased. The EL showed an irregular behavior. The active SLB showed smaller forces than passive, in large deflections.ConclusionsThe SLB and the ML exhibit standard force patterns during unloading, while the elastomeric ligatures exhibit a randomly distributed force release behavior.

Biofilm formation on polytetrafluoroethylene coated versus uncoated brackets in a South Indian population

Objective: This study compared the biofilm formation pattern on Polytetrafluoroethylene (PTFE) coated orthodontic brackets with that of uncoated ones. Methods: Fifteen teen aged patients were enrolled for eight weeks with their second premolar symmetrically bonded with uncoated and PTFE-coated orthodontic brackets. Upon completion, the elastomeric ligatures were deboned and removed. Rutherford backscattering detection (RBSD) method was adopted and the RBSD photographs were validated. Results: Analysis showed a total surface area of 21.7 ± 0.7 mm2 per bracket. The biofilm formation was noticed in 4.0 ± 3.6 % (0.9 ± 0.8 mm2) of the bracket surface in case of PTFE-coated brackets versus 22.2 ± 5.4 per cent (4.8 ± 1.2 mm2) on uncoated brackets and in case of PTFE-coated brackets highest amount of biofilm formation was evident in ‘mesial surfaces’ (6.58 ± 4.4 %) and the lowest on the occlusal surfaces (1.29 ± 1.2 %). The comparisons of the 2 interventions/procedures showed significant differences in all the 5 views (p=0.001 for all). Conclusion: The research findings suggest that coating the brackets with PTFE reduces biofilm adhesion to a larger extent and minimizes iatrogenic side effects. Key words: Biofilm formation, Polytetrafluoroethylene coating, Orthodontic brackets, RBSD photographs.

Discoloration and force degradation of orthodontic elastomeric ligatures.

ABSTRACTOBJECTIVE: The aim of the present study was to evaluate color changes and force degradation of orthodontic elastomeric ligatures in different stretching patterns during a 8-weeks period. METHODS: Two elastomers with the minimum and two with the maximum color changing, and gray elastomers of two brands (American Orthodontics and Ortho Technology) were selected according to an opinion poll with clinicians and color changes after 4 weeks of intraoral use were evaluated. These elastomers were mounted on special jigs fabricated using a CAD-CAM technique, underwent different stretching patterns and the force was measured in 0, 24 hours, 2, 4 and 8 weeks. During in vivo part of the study, force levels of elastomers were measured after 4 weeks on a material testing machine. Data were analyzed with four-way ANOVA and Tukey post hoc tests.RESULTS: All the elastomers showed color changing but the degree of color stability was significantly different. The mean force degradation was higher in 1-mm stretch groups. After 8 weeks, the average residual force of elastomers was 1.45 ± 0.18 N and the maximum force decay was seen in the elastomers that exhibited the maximum initial force.CONCLUSION: There is significant relationship between the stretching pattern and the amount of residual force of elastomers. Elastomers with higher initial forces exhibited higher percentages of force loss after 8 weeks. It seems that there is a relationship between initial color and color changing of elastomers.

Cytotoxicity of three commercial orthodontic elastomeric ligature brands

This study aimed to evaluate cytotoxicity of three commercial brands of orthodontic elastomeric ligatures. Materials and Methods: The three commercial orthodontic elastomeric ligature brands were C-brand, T-brand and U-brand from different manufacturing countries. The cytotoxic assay was performed using cell cultures (L929) which were subjected to the cell viability test with methyl-tetrazolium (MTT). The L929 cell line was grown in 96-well tissue culture plates (1×10 5 cells/cm 3 ). Elastomeric ligatures (0.2 g) from each brand was placed in 1 ml of Minimum Essential Medium (MEM) at 37°C with 5% CO 2 at 100% humidity in an incubator for 24 hours. After incubation, the cell mitochondrial activity was evaluated by the MTT test for detecting viable cells from optical density according to ISO 10993-5: 2009 (E) test procedure. Cytotoxic effects were determined by the percentage of cell viability. Results: Microscopic investigation showed that all commercial elastomeric ligatures caused alterations in the fibroblast cell morphology from an elongated to a spherical form. The cell viability of C-brand, T-brand and U-brand were 51.10, 73.04 and 93.04%, respectively. Conclusion: T-brand and U-brand orthodontic elastomeric ligatures were non cytotoxic potential. U-brand had the greatest cell viability and C-brand had the lowest cell viability at 24 hours.

Esthetic perception of orthodontic appliances by Brazilian children and adolescents.

ABSTRACTObjective: The objective of this present study was to understand how children and adolescents perceive esthetic attractiveness of a variety of orthodontic appliances. It also analyzed preferences according to patients' age, sex and socioeconomic status. Methods: A photograph album consisting of eight photographs of different orthodontic appliances and clear tray aligners placed in a consenting adult with pleasing smile was used. A sample of children or adolescents aged between 8 and 17 years old (n = 276) was asked to rate each image for its attractiveness on a visual analog scale. Comparisons between the appliances attractiveness were performed by means of nonparametric statistics with Friedman's test followed by Dunn's multiple comparison post-hoc test. Correlation between appliances and individuals' socioeconomic status, age, sex, and esthetic perception was assessed by means of Spearman's correlation analysis. Results: Attractiveness ratings of orthodontic appliances varied nonsignificantly for children in the following hierarchy: traditional metallic brackets with green elastomeric ligatures > traditional metallic brackets with gray elastomeric ligatures > sapphire esthetic brackets; and for adolescents, as follows: sapphire esthetic brackets > clear aligner without attachments > traditional metallic brackets with green elastomeric ligatures. The correlation between individuals' socioeconomic status and esthetic perception of a given appliance was negative and statistically significant for appliances such as the golden orthodontic brackets and traditional metallic brackets with green elastomeric ligatures. Conclusion: Metal appliances were considered very attractive, whereas aligners were classified as less attractive by children and adolescents. The correlation between esthetic perception and socioeconomic status revealed that individuals with a higher socioeconomic level judged esthetics as the most attractive attribute. For those with higher economic status, golden orthodontic brackets and traditional metallic brackets with green elastomeric ligatures were assessed as the worst esthetic option.

Evaluation of Force Decay of Elastomeric Ligatures in Simulated Oral Environment

Evaluation of Force Decay of Elastomeric Ligatures in Simulated Oral Environment

Analysis of the Influence of Food Colorings in Esthetic Orthodontic Elastomeric Ligatures

Proposition:The purpose of this study was to evaluate in vitro the color changes of esthetic orthodontic elastomeric ligatures of different shades when exposed to four food colorings commonly found in the diet of patients.Materials and Methods:The sample consisted of esthetic orthodontic elastomeric ligatures in the colors pearl, pearl blue, pearl white and colorless, which were immersed for 72 hours in five different solutions: distilled water (control group), coffee, tea, Coca-Cola ® and wine. The color changes of the esthetic orthodontic elastomeric ligatures were measured with the aid of a spectrophotometer, at T1 - as provided by the manufacturer; and T2 - after colorings process. Results: The results indicated that the esthetic orthodontic elastomeric ligatures of all initial hues are susceptible to pigmentation. Among the evaluated colors, all changed the finished look and the color of the samples tested. In ascending order, the color of the samples was as follows: distilled water, Coca-Cola®, black tea, wine and coffee. Conclusion:The substances that have a greater potential for pigmentation in esthetic orthodontic elastomeric ligatures were black tea, wine and coffee, respectively. All shades of esthetic orthodontic elastomeric ligatures are susceptible to color change.

Forces released during alignment with a preadjusted appliances with SPEED supercable wire and different types of elastomeric ligatures

Forces released during alignment with a preadjusted appliances with SPEED supercable wire and different types of elastomeric ligatures

Forces released during alignment with a preadjusted appliances with SPEED supercable wire and different types of elastomeric ligatures

Introduction: The purpose of this in vitro study was to evaluate a new combination of wire and ligature to reduce friction further by combining slide ligatures and supercable wires. Materials and Methods: The testing model consisted of five stainless steel 0.022 inch preadjusted brackets for second premolar, first premolar, canine, lateral incisor, and central incisor. The canine bracket was welded to a sliding bar that allowed different vertical positions. The forces generated by five sizes of wires superelastic nickel-titanium (SE Ni-Ti) (Unitek Nitinol Super-Elastic Archwire) of diameter 0.012, 0.014, 0.016, 0.018, and 0.020 inch and three sizes of SPEED supercable wires (0.016, 0.018, and 0.022 inch) with the two types of elastomeric ligatures; conventional elastomeric ligatures (CELs) (Unitek, silver mini modules, with inside diameter of 1.3 mm and thickness of 0.9 mm) and nonconventional elastomeric ligatures (NCELs) (Slide, Leone Orthodontic Products, Sesto Fiorentino, Firenze, Italy) at different amounts of upward canine misalignment (CM) (1.5, 3, 4.5, and 6 mm) were recorded. Results and Conclusions: Significant differences between CEL and NCEL were found for all tested variables ( P - 0.01) a noticeable amount of force was generated with the NCEL at all four canine positions with all three wire sizes (from about 50 to about 150 g). With 4.5 mm of CM or more, the average amount of released force with the CEL was approximately zero.

Force Decay of Elastomeric Ligature Used for Active Tieback a Product Comparison Study

Force Decay of Elastomeric Ligature Used for Active Tieback a Product Comparison Study

Evaluation of friction produced by self-ligating, conventional and Barbosa Versatile brackets

Abstract Introduction The Barbosa Versatile bracket design may provide lower frictional force and greater sliding. However, no in vitro studies have shown its sliding mechanisms and frictional resistance, particularly in comparison with other self-ligating or conventional brackets. Objective To compare the frictional resistance among self-ligating brackets (EasyClip/ Aditek, Damon MX/ Ormco and In Ovation R/ GAC); conventional brackets (Balance Roth/ GAC, and Roth Monobloc/ Morelli); and Barbosa Versatile bracket (Barbosa Versatile/ GAC) with different angles and arch wires. Material and method Brackets were tested with the 0.014", 0.018", 0.019"×0.025" and 0.021"×0.025" stainless steel wires, with 0, 5, 10, 15 and 20 degree angulations. Tying was performed with elastomeric ligature for conventional and Barbosa Versatile brackets, or with a built-in clip system of the self-ligating brackets. A universal testing machine was used to obtain sliding strength and friction value readouts between brackets and wires. Result Three-way factorial ANOVA 4×5×6 (brackets × angulation × wire) and Tukey tests showed statistically significant differences for all factors and all interactions (p&lt;0.0001). Static frictional resistance showed a lower rate for Barbosa Versatile bracket and higher rates for Roth Monobloc and Balance brackets. Conclusion The lowest frictional resistance was obtained with the Barbosa Versatile bracket and self-ligating brackets in comparison with the conventional type. Increasing the diameter of the wires increased the frictional resistance. Smaller angles produced less frictional resistance.

Effect on Mechanical Properties of Orthodontic Elastomeric Ligatures on Immersion in Disinfecting Solutions - an in vitro Study

Effect on Mechanical Properties of Orthodontic Elastomeric Ligatures on Immersion in Disinfecting Solutions - an in vitro Study

Evaluation of Tensile and Friction Resistance of Various Orthodontic Elastomeric Ligatures

Evaluation of Tensile and Friction Resistance of Various Orthodontic Elastomeric Ligatures

Force decay and dimensional changes of thermoplastic and novel thermoset elastomeric ligatures.

To compare over a period of 8 weeks (1) the force decay and (2) the dimensional changes between thermoplastic (TP) and thermoset (TS) elastomeric ligatures. TP and TS elastomeric ligatures were obtained from Rocky Mountain Orthodontics™. The TS ligatures were custom made specifically for this study. The sample included 72 clear TP and 72 clear TS elastomeric ligatures. The experiment was performed in a simulated oral environment (pH of 6.75) at 37°C. The remaining forces and the dimensional changes were measured at different time points over a period of 8 weeks. Student's t-tests revealed significant differences in percent force loss, percent change in outer diameter, percent change in inner diameter, and percent change in wall thickness between TP and TS elastomeric ligatures across all time points (P < .001). The difference in percent change in width between TP and TS elastomeric ligatures was not significant at all time points (P > .05). The mean difference in force loss between TP and TS across all time points was 22.91%. The TP and TS specimens exhibited 93.04% and 77.41% force loss, respectively, at the 28th day. This novel TS elastomeric ligature showed significantly less force decay and dimensional changes over time; therefore, it might be superior during initial leveling and aligning and during finishing stages. Using a transfer jig to prevent relaxation of the specimens before force measurement showed that force decay of commercially available elastomeric ligatures was greater than that described in previous publications.

Frictional Characteristics of the Newer Low-friction Elastomeric Ligatures

ABSTRACTAimThe aim of thisin vitrostudy was to investigate the efficiency of the new generation of elastomeric ligatures with innovative designs (SlideTMand AlastiKTMEasy-to-Tie) in reducing frictional resistance (FR) during sliding mechanics as compared with conventional ligatures.Materials and MethodsSixty 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.ResultsThere was statistically significant difference in FR among all the four groups of ligatures tested (p &lt; 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.ConclusionSlideTMligatures 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 articleVivek 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.

Plaque accumulation and Streptococcus mutans levels around self-ligating bracket clips and elastomeric modules: A randomized controlled trial

Aim To determine the effect of two different ligating systems that is, elastomeric modules and self-ligating (SL) bracket systems (Smartclip - 3M Unitek) with respect to harboring bacterial plaque in fixed orthodontic treatment. Objectives To assess, evaluate, and compare the amount of plaque accumulation and Streptococcus mutans colonization around elastomeric ligation and SL clips in the smart clip appliance. Materials and Methods A total of 111 orthodontic patients scheduled for fixed orthodontic treatments were selected for this split maxillary arch study. All the patients were bonded with smart-clip (3M Unitek) SL brackets, and the wire was placed into the bracket slots, on the randomly selected hemi arch, elastomeric modules were placed for the study to be conducted. Microbial and periodontal plaque accumulation was recorded at 3-time intervals post ligation. Plaque index-by Silness and Loe, modified Quigely Hein index, bleeding on probing were evaluated, and biofilm was collected from the tooth surface after 30 days and placed in petri dishes containing Mitis Salivarius agar for bacterial culturing. Result It was observed that the side where ligation was done with elastomeric modules accumulated more plaque and increase in S. mutans colony forming units as compared to the side without external ligation (P &lt; 0.05). Conclusion Reduced bacterial colonization and better plaque control was seen with SL orthodontic bracket appliance system as compared to conventional ligation method.

Citotoxicity of nonlatex elastomeric ligatures of orthodontic use

The aim of this study is to evaluate cytotoxicity between polyurethane and non-latex orthodontic elastomeric ligatures. Seven elastomeric ligatures of black-coloured from different manufactures (3 non-latex, 3 polyurethane and 1 latex) were divided into 7 groups of 10 elastics each: Group UK (nonlatex, 3M Unitek), Group TP (nonlatex, TP Orthodontics), Group AO (nonlatex, American Orthodontics), Group O (Polyurethane, OrthoSource), Group M (Polyurethane, Morelli), Group TD (Polyurethane, Tecnident) and Group TC (latex - Control, TP Orthodontics). The cytotoxicity essay was performed using cell cultures (L-929 line cells, mouse fibroblast) that were submitted to the cell viability test with neutral red (dye-uptake) at 1, 2, 3, 7 and 28 days. Analysis of variance (ANOVA) with 1-way analysis followed by the Tukey post hoc test were employed (p .05). There was a statistically differences (p .05) between the groups O, M and TD at in all experimental times. It can be concluded that the nonlatex elastomeric ligatures of Unitek, TP Orthodontics, and American Orthodontics showed higher cell viability compared to others ligatures.