Conventional Elastomeric Ligatures Research Articles

Evaluation of Frictional Forces Generated between Three Different Ligation Methods with Four Different Sizes of Orthodontic Archwires: An In vitro Study.

Aim:This in vitro study was done to evaluate and compare the frictional forces produced by a passive self-ligating bracket (SLB) and two types of elastomeric ligatures (unconventional elastomeric ligatures [UELs] and conventional elastomeric ligatures [CELs]) on a conventional bracket used with four types of wires.Materials:In this in vitro study, 8 numbers of conventional preadjusted edgewise appliance stainless steel brackets and 4 numbers of passive SLBs were tested. Four types of archwires and two types of ligatures were tested. Brackets were divided into three groups – Group I, Group II, and Group III. All the three groups were further divided into four subgroups based on different archwires.Methods:Custom-made mounting jig was specially constructed for this study – upper member and lower member. After the samples were mounted, traction test was conducted using universal testing machine and readings were tabulated for all specimens. The variables in each group were subjected to one-way analysis of variance.Results:All the three groups were tested for its total friction, static friction, and kinetic friction. SLBs showed a static mean little lower and had kinetic mean little greater than conventional bracket with unconventional module.Conclusion:UELs on conventional brackets and SLBs are able to produce lower frictional force when compared with CELs on conventional brackets.

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.

A comparative study of the physical and elastic properties of new generation elastomeric ligatures with conventional elastomeric ligatures

Context: One of the most common methods of securing arch wires to orthodontic brackets is the application of elastomeric ligatures. New generation elastomeric ligatures were introduced to overcome the disadvantages of force decay and staining in conventional ligatures. Aims: The aim was to compare the physical and elastic properties of new generation elastomeric ligatures with the conventional elastomeric ligatures. Materials and Methods: Four groups of clear elastomeric modules (conventional polyurethane based modules, latex free elastomeric modules, alastik easy to tie modules, silver and silicone impregnated super ligatures) were tested for tensile properties, frictional resistance, and color stability in as received condition and following 1-week, 2 weeks, and 1-month of intra-oral exposure. A universal testing machine was used for testing tensile properties. The color stability was tested by measuring the color change using scanned images of the modules at different time periods. Statistical Analysis: Two-way ANOVA, post-hoc multiple comparisons Bonferroni-Dunn test and the paired t-test were used. Results: The alastik group showed the highest mean tensile strength and super ligatures showed the lowest tensile strength values. There was a statistically significant decrease in the mean tensile strength in all groups following intra-oral exposure (P Conclusions: There are significant differences in physical and elastic properties of different brands of ligatures, which should be considered during the selection of these products.

Effect of 2 elastomeric ligatures on microbial flora and periodontal status in orthodontic patients

The aim of this study was to compare the effects of a nonconventional elastomeric ligature (Slide; Leone, Florence, Italy) with those of a conventional elastomeric ligature (Ormco, Orange, Calif) on microbial flora and periodontal status in orthodontic patients. A total of 13 orthodontic patients scheduled for fixed orthodontic treatment were selected for this study. The use of Slide and conventional elastomeric ligatures in fixed orthodontic appliances was tested. Microbial and periodontal records were obtained before bonding and 1 and 5 weeks after bonding. For the statistical analysis and calculations, SPSS software (version 15.0; SPSS, Chicago, Ill) was used. In the statistical decisions, P <0.05 values were accepted as significantly different. No significant differences between Slide and conventional elastomeric ligatures were evident at 1 week or 5 weeks after bonding, with regard to gingival index, plaque index, gingival bleeding index, or pocket depth scores (P >0.05). Similarly, aerobic and anaerobic bacteria counts did not differ significantly on the surface or on the elastics (P >0.05). Although the Slide ligatures cover the total surface of the bracket, they do not cause significantly more plaque accumulation or periodontal problems than do the conventional elastomeric ligatures.

Evaluation of friction in orthodontics using various brackets and archwire combinations-an in vitro study.

The aim of this study was to compare frictional resistance which was produced between conventional brackets (0.022 slot Otho-Organiser) and self ligating brackets (active Forestadent and passive Damon III) by using various arch wire combinations (0.016 Niti, 0.018 Niti, 0.017 x 0.025 SS and 0.019 x 0.025 SS). An experimental model which consisted of 5 aligned stainless steel 0.022-in brackets was used to assess frictional forces which were produced by SLBs (self ligating brackets) and CELs (conventional elastomeric ligatures) with use of 0.016 nickel titanium, 0.018 nickel titanium, 0.017 X 0.025"stainless steel and 0.019 X 0.025"stainless steel wires. One way ANOVA test was used to study the effect of the bracket type, wire alloy and section on frictional resistance test . Conventional brackets produced highest levels of friction for all bracket/archwire combinations. Both Damon III and Forestadent brackets were found to produce significantly lower levels of friction when they were compared with elastomerically tied conventional brackets. SLBs are valid alternatives for low friction during sliding mechanics.

Frictional resistance in monocrystalline ceramic brackets with conventional and nonconventional elastomeric ligatures

BackgroundThe objective of this study was to compare the frictional forces generated by three types of monocrystalline ceramic brackets coupled with conventional elastomeric ligatures (CEL) and nonconventional elastomeric ligatures (NCEL) during the alignment of apically displaced teeth at the maxillary arch.MethodsAll tests (a total of 480 tests) were carried out in a dry state on a universal testing machine with a testing model consisting of three 0.022-in. monocrystalline ceramic preadjusted brackets (from the maxillary right second premolar through the right central incisor). The canine bracket was bonded to a sliding bar that allowed for different vertical positions. The frictional forces generated by a 0.012- and 0.014-in. superelastic nickel titanium wire (SENT) with conventional and nonconventional ligatures at various amounts of canine misalignment (1.5, 3.0, 4.5, and 6.0 mm) were recorded. Comparisons between the different types of bracket-wire-ligature systems were carried out by means of analysis of variance on ranks with Tukey's post hoc test (P < 0.05).ResultsNo significant differences were assessed among the three types of monocrystalline brackets with NCEL when coupled with 0.012-in. SENT. Radiance brackets with NCEL coupled with 0.014-in. SENT showed significantly greater frictional force than Inspire Ice brackets and Pure brackets with NCEL. A significantly greater amount of frictional force was generated with CEL when compared with NCEL for all the tested variables, with the exception of the Pure brackets with 0.012-in. SENT at 1.5 and 3.0 mm of canine misalignment where similar frictional forces were found.ConclusionsNonconventional elastomeric ligatures are able to reduce friction in monocrystalline ceramic brackets.

Comparative study of frictional forces generated by NiTi archwire deformation in different orthodontic brackets: In vitro evaluation

INTRODUCTION: The purpose of this study was to compare the frictional forces between 0.014-in NiTi wires (Aditek) with 4 mm horizontal deflection and brackets with different archwire ligation systems. METHODS: Four types of self-ligating brackets (Damon MX, Easy Clip, Smart Clip and In-Ovation), a triple bracket (Synergy) and a twin bracket with 8-shaped ligature (Tecnident) were tested. Twin brackets with conventional elastomeric ligatures (Morelli) were used as control group. Tests were repeated 10 times for each bracket/archwire combination. Frictional forces were measured in an Instron universal tensile machine at 3 mm/minute speed and a total displacement of 6 mm. Statistical analysis comprised ANOVA and Dunnett's multiple comparison post hoc test. RESULTS: Deflection-induced frictional (DIF) forces increased in the following order: Synergy, Damon, 8-shaped Ligature, Easy Clip, In-Ovation, Smart-Clip and conventional ligatures. The differences among groups were significant, with the exception of the 8-shaped ligature groups which was equal to the Damon and Easy Clip groups. CONCLUSIONS: Compared to conventional ligatures, all ligation systems tested reduced frictional forces. However, such reduction varied according to the ligation system employed.

Clinical efficiency of nonconventional elastomeric ligatures in the canine retraction phase of preadjusted edgewise appliance therapy: An in-vivo study

Various ligation techniques and materials have been shown to affect the frictional resistance and the rate of tooth movement with sliding mechanics for space closure. The aim of this study was to evaluate the clinical efficiency of nonconventional elastomeric ligatures and conventional elastomeric ligatures during the canine retraction phase by comparing the rates of canine retraction. The 20 patients (12 female, 8 male) in our sample had individual canine retraction (in the first premolar extraction space) in each quadrant (2 maxillary, 2 mandibular) with nonconventional elastomeric ligatures and conventional elastomeric ligatures on either side of the arch. The amount of canine retraction in each interval of 1 month was determined. The rate of canine retraction was calculated and subjected to statistical calculations. The rates of canine retraction were higher with the nonconventional elastomeric ligatures. However, no statistically significant difference was observed in relation to the maxillary arch. Clinically, in most instances, canine retraction was completed in the same interval in both groups. No significant difference in the rate of canine retraction was observed between the nonconventional elastomeric ligature and conventional elastomeric ligature groups in the maxillary arch. Clinically, the nonconventional elastomeric ligature group showed no reduction in time required for complete canine retraction in the maxillary and mandibular arches.

Frictional resistance of orthodontic wires tied with 3 types of elastomeric ligatures

The aims of this study were to determine and compare frictional resistance obtained by low-friction and conventional elastomeric ligatures in the presence of artificial saliva, and observe whether this variable changed after 21 days. Super Slick® low-friction elastomeric ligatures and conventional ligatures of the brands TP conventional® and Unitek® were placed on standard edgewise maxillary central incisor metal brackets, slot .022" × .028" tying rectangular orthodontic wires .018" × .025". Three experimental groups were arranged according to the type of ligature and a control group in which no wires were used. The friction values obtained between the bracket/wire/ligature set were measured using a Universal Test Machine at a speed of 20 mm/minute, at two experimental time intervals: T0 - immediately after specimen fabrication; and T1 - 21 days after fabrication and immersion in artificial saliva at 37 ºC. Conventional Unitek ligatures and the low-friction ligature (Super Slick) showed the lowest friction values at T0. After 21 days (T1), however, conventional Unitek ligatures presented the lowest value. All groups assessed from T0 to T1 showed a numerical reduction in friction values, suggesting that time, heat and humidity may cause elastic degradation, however this was not verified statistically (P > 0.05).

Orthodontic forces released by low-friction versus conventional systems during alignment of apically or buccally malposed teeth

The aim of the present study was to analyse the forces released by passive stainless steel self-ligating brackets (SLBs) and by a non-conventional elastomeric ligature-bracket system on conventional brackets ([slide ligatures on conventional brackets (SLCB)]) when compared with conventional elastomeric ligatures on conventional brackets (CLCB) during the alignment of apically or buccally malposed teeth in the maxillary arch. An experimental model consisting of five brackets was used to assess the forces released by the three different bracket-ligature systems with 0.012-inch super-elastic (SE) nickel-titanium (NiTi) wires in the presence of different amounts of apical or buccal canine misalignment of the canine (ranging from 1.5 to 6 mm). The forces released by each wire/bracket/ligature combination with the three different amounts of apical or buccal canine misalignment were tested 20 times. Comparisons between the different types of wire/bracket/ligature systems were carried out by means of analysis of variance on ranks with Dunnett's post hoc test (P < 0.05). No difference in the amount of force released in presence of a misalignment of 1.5 mm was recorded among the three systems. At 3 mm of apical misalignment a significantly greater amount of orthodontic force was released by SLB or SLCB when compared with CLCB, while no significant differences were found among the three systems at 3 mm of buccal canine displacement. When correction of a large amount of misalignment (6 mm) was attempted, a noticeable amount of force for alignment was still generated by the passive SLB and SLCB systems while no force was released in presence of CLCB.

Forces released by nonconventional bracket or ligature systems during alignment of buccally displaced teeth

The aim of this study was to analyze the forces released by 4 types of passive stainless steel self-ligating brackets and 2 nonconventional elastomeric ligature bracket systems compared with conventional elastomeric ligatures on stainless steel brackets during the alignment of buccally displaced teeth. A model consisting of 5 brackets (from second premolar through central incisor) was used to assess the forces released by the 7 bracket-ligature systems with 0.012- or 0.014-in superelastic wires with various amounts of buccal canine displacement (1.5-6.0 mm). The comparisons between the different types of bracket-wire-ligature systems were performed with 3-way ANOVA with the Tukey post-hoc test (P <0.05). For buccal misalignments of 1.5 and 3.0 mm, both low-friction and conventional systems released forces for bracket alignment ranging from about 30 to 160 g. For greater buccal displacements (4.5 and 6.0 mm), the low-friction systems produced a significant magnitude of force, but it dropped to 0 g for the conventional system. Nonconventional elastomeric ligature bracket systems produced levels of force for tooth movement that were similar to those generated by passive self-ligating brackets.

Editor's Summary and Q&A: Forces released by nonconventional bracket or ligature systems during alignment of buccally displaced teeth

<h3>Introduction</h3> The aim of this study was to analyze the forces released by 4 types of passive stainless steel self-ligating brackets and 2 nonconventional elastomeric ligature bracket systems compared with conventional elastomeric ligatures on stainless steel brackets during the alignment of buccally displaced teeth. <h3>Methods</h3> A model consisting of 5 brackets (from second premolar through central incisor) was used to assess the forces released by the 7 bracket-ligature systems with 0.012- or 0.014-in superelastic wires with various amounts of buccal canine displacement (1.5-6.0 mm). The comparisons between the different types of bracket-wire-ligature systems were performed with 3-way ANOVA with the Tukey post-hoc test (<i>P</i> <0.05). <h3>Results</h3> For buccal misalignments of 1.5 and 3.0 mm, both low-friction and conventional systems released forces for bracket alignment ranging from about 30 to 160 g. For greater buccal displacements (4.5 and 6.0 mm), the low-friction systems produced a significant magnitude of force, but it dropped to 0 g for the conventional system. <h3>Conclusions</h3> Nonconventional elastomeric ligature bracket systems produced levels of force for tooth movement that were similar to those generated by passive self-ligating brackets.

Forces Produced by Different Nonconventional Bracket or Ligature Systems during Alignment of Apically Displaced Teeth

To analyze the forces released by four types of passive stainless steel self-ligating brackets (SLBs), and by two nonconventional elastomeric ligature-bracket systems when compared with conventional elastomeric ligatures on conventional stainless steel brackets during the alignment of apically displaced teeth at the maxillary arch. An experimental model consisting of five brackets was used to assess the forces released by the seven different ligature-bracket systems with 0.012'' or 0.014'' superelastic nickel titanium wire in the presence of different amounts of apical displacement of the canine (ranging from 1.5 mm to 6 mm). Comparisons between the different types of bracket/wire/ ligature systems were carried out by means of ANOVA on ranks with Dunnett's post hoc test (P < .05). When correction of a misalignment greater than 3 mm is attempted, a noticeable amount of force for alignment is generated by passive SLBs and nonconventional elastomeric ligature-bracket systems, and a null amount of force is released in the presence of conventional elastomeric ligatures on conventional brackets. When minimal apical displacement is needed (1.5 mm), the differences in performance between low-friction and conventional systems are minimal. These differences become significant when correction of a misalignment of greater than 3.0 mm is attempted.

Frictional resistance in plastic preadjusted brackets ligated with low-friction and conventional elastomeric ligatures

To compare frictional resistance of the plastic preadjusted brackets ligated with the low-friction ligatures with those of the conventional elastomeric ligatures. In vitro study. Department of Orthodontics, Faculty of Dentistry, Kyushu University, Fukuoka, Japan. The testing model consisted of four 0.022-inch plastic preadjusted brackets for the first premolar, the canine, the lateral incisor, and the central incisor. A superelastic nickel-titanium 0.014-inch wire and a stainless steel 0.019 x 0.025-inch wire were used for this test. The brackets were either aligned or out of line by 0.5, 1.0, 1.5 and 2.0 mm for the 0.014-inch wire and aligned for the 0.019 x 0.025-inch wire. The frictional forces in plastic preadjusted brackets with low-friction ligatures and conventional elastomeric ligatures were measured at a pulling speed of 0.1 mm/second. Welch t-tests were used to compare the mean differences of each testing measurement between the low-friction and the conventional elastomeric ligatures. In both use of the superelastic nickel-titanium 0.014-inch wire and the stainless steel 0.019 x 0.025-inch wire, the brackets with the low-friction ligatures showed significantly lower frictional forces than those of the conventional elastomeric ligatures in both aligned and all misaligned brackets (P < 0.0001). The study found the significantly lower frictional forces for the low-friction ligatures than those of the conventional elastomeric ligatures.

Forces in the Presence of Ceramic Versus Stainless Steel Brackets with Unconventional vs Conventional Ligatures

To compare the forces resulting from four types of bracket/ligature combinations: ceramic brackets and stainless steel brackets combined with unconventional elastomeric ligatures (UEL) and conventional elastomeric ligatures (CEL) during the leveling and aligning phases of orthodontic therapy. The testing model consisted of five 0.022-inch preadjusted brackets (second premolar, first premolar, canine, lateral incisor, and central incisor) for each of the two bracket types. The canine bracket was welded to a sliding bar that allowed for different amounts of offset in the gingival direction. The forces generated by a 0.014-inch superelastic nickel titanium wire in the presence of either the UEL or CEL bracket/ligature systems at different amounts of upward canine misalignment (1.5 mm, 3 mm, 4.5 mm, and 6 mm) were recorded. Significant differences were found between UEL and CEL systems for all tested variables (P < .01) with the exception of the canine misalignment of 1.5 mm. The average amount of recorded force in the presence of CEL was negligible with 3.0 mm or greater of canine misalignment. On the contrary, during alignment, a force available for tooth movement was recorded in the presence of both ceramic and stainless steel brackets when associated with UEL. The type of ligature used influenced the actual amount of force released by the orthodontic system significantly more than the type of bracket used (stainless steel vs ceramic).

Forces released during sliding mechanics with passive self-ligating brackets or nonconventional elastomeric ligatures

The aim of this study was to evaluate the frictional forces generated by 4 types of passive stainless steel self-ligating brackets (SLBs) and by nonconventional elastomeric ligatures (NCEL) and conventional elastomeric ligatures (CEL) during sliding mechanics. An experimental model consisting of 5 aligned stainless steel 0.022-in brackets was used to assess frictional forces produced by the SLBs, NCEL, and CEL with a 0.019 x 0.025-in stainless steel wire. Significantly smaller static and kinetic forces were generated by the SLBs and NCEL (<2 g) compared with the CEL (>500 g). No significant differences were found within the different types of SLBs, or between these and the NCEL. SLBs and NCEL are valid alternatives for low friction during sliding mechanics.

Forces released by esthetic preadjusted appliances with low-friction and conventional elastomeric ligatures

In this in-vitro study, we compared the forces generated by 2 types of esthetic brackets (Aqua [Leone Orthodontic Products, Sesto Fiorentino, Florence, Italy] and Mystique [GAC International, Bohemia, NY]) in association with low-friction ligature systems (Slide [Leone Orthodontic Products] and Neo-Clips [GAC International], respectively) and by the same brackets combined with conventional elastomeric ligatures (CEL) during the leveling and aligning phases. The testing model consisted of 5 esthetic ceramic 0.022-in preadjusted brackets for the second premolar, the first premolar, the canine, the lateral incisor, and the central incisor. The canine bracket was bonded to a sliding bar that allowed for various vertical positions. The forces generated by a 0.014-in superelastic nickel titanium wire, with the 2 types of esthetic low-friction systems (Aqua with Slide and Mystique with Neo-Clips) and the same esthetic brackets with CEL at various amounts of canine misalignment (1.5, 3, 4.5, and 6 mm) were recorded. A significantly greater amount of force was released with low-friction systems when compared with CEL systems for all the tested variables (P < .05), with the exception of the 1.5-mm canine misalignment, and the 6.0-mm canine misalignment limited to Mystique with Neo-Clips. Similar forces were released with both esthetic low-friction systems. The average amount of released force with CEL was approximately zero at 3.0 mm or more of canine misalignment.

Forces released during alignment with a preadjusted appliance with different types of elastomeric ligatures

The purpose of this in-vitro study was to compare the forces generated by new nonconventional elastomeric ligatures (NCEL) and conventional elastomeric ligatures (CEL) during leveling and aligning phases. The testing model consisted of 5 stainless steel 0.022-in preadjusted brackets for second premolar, first premolar, canine, lateral incisor, and central incisor. The canine bracket was welded to a sliding bar that allowed for different vertical positions. The forces generated by 3 sizes of wires (0.012-, 0.014-, and 0.016-in superelastic nickel-titanium) with the 2 types of elastomeric ligatures at different amounts of upward canine misalignment (1.5, 3, 4.5, and 6 mm) were recorded. Significant differences between CEL and NCEL were found for all tested variables (P <.01) with the exception of the 0.014- and 0.016-in wires at canine misalignment of 1.5 mm. A noticeable amount of force was generated with the NCEL at all 4 canine positions with all 3 wire sizes (from about 50 to about 150 g). With 4.5 mm of canine misalignment or more, the average amount of released force with the CEL was approximately zero.

Friction produced by types of elastomeric ligatures in treatment mechanics with the preadjusted appliance.

The objective was to compare the frictional forces generated by new nonconventional passive elastomeric ligatures (NCL) and conventional elastomeric ligatures (CL) under dry conditions. An experimental model reproducing the right buccal segment of the upper arch and consisting of five stainless steel 0.022-inch preadjusted brackets (from the second premolar through the central incisor) was used to assess both static and kinetic frictional forces produced by NCL and CL. The frictional forces generated by the 0.019 x 0.025-inch stainless steel wire with the two types of elastomeric ligatures were recorded by sliding the wire into the aligned brackets. The friction produced by the 0.014-inch superelastic nickel titanium wire was evaluated both in the presence of aligned brackets and of three-mm misaligned canine bracket. The amount of both static and kinetic frictions were minimal (<10 g) in the NCL group in the presence of aligned brackets with both types of wires, whereas it ranged from a minimum of 95.6 g for the 0.014-inch superelastic nickel titanium wire to a maximum of 590.7 g for the 0.019 x 0.025-inch stainless steel wire when using CL. The amount of both static and kinetic frictions in the presence of a misaligned canine bracket in the NCL group were less than half of that shown by the CL group. A recently developed passive ligature system is able to produce significantly lower levels of frictional forces in vitro when compared with conventional elastomeric modules.