Ligature Systems Research Articles

Torque efficiency of acustomized lingual appliance : Performance of wires with three different ligature systems.

Torque control in lingual orthodontics is key to obtain optimal esthetic results. The aim of this in vitro experimental study was to verify the efficiency of the ligature-archwire-slot system in torque control using acustomized lingual appliance. An idealized cast with eight extracted human teeth was created and aset of customized lingual brackets was obtained. Tests were performed with the following wires: 0.016″ × 0.022″ nickel-titanium (NiTi), 0.016″ × 0.024″ stainless steel (SS), 0.017″ × 0.025″ βIII titanium (βIIITi), 0.0182″ × 0.0182″ βIIITi, 0.018″ × 0.025″ SS, 0.018″ × 0.025″ NiTi, 0.018″ × 0.025″ βIIITi, and three types of ligatures were tested using auniversal testing machine to calculate the efficiency in torque control. Ablind statistical analysis was performed. Based on posthoc multiple comparisons, differences were found for two of the three ligatures when using the 0.016″ × 0.022″ NiTi wires (p < 0.001 for both ligatures). When considering all ligatures, 0.018″ × 0.025″ SS and 0.018″ × 0.025″ βIIITi were significantly different from all other wires (p < 0.001 in all cases). With amoment of 5 Nmm, the 0.016″ × 0.022″ NiTi wire developed median angles of 26.7, 29.8, and 38.7° with the three ligatures, respectively, while the 0.018″ × 0.025″ SS developed median angles of 12.9, 10.7, and 12.7°, respectively. The ligature type and geometry did not affect the efficiency of torque control, except for the 0.016″ × 0.022″ NiTi wire. The wires generating the greatest moments were the 0.018″ × 0.025″ SS and 0.018″ × 0.025″ βIIITi.

Description and Executability of a Novel Pre-tied Mini Ligature (Miniloop) in Laparocopic Ovariectomy in Cats

Background: Ovariectomy(OVE) and ovariohysterectomy (OVH) are the most performed surgical procedures in Veterinary Medicine. In videosurgery, both in stray animals at sterilization campaigns and in the increasing demand of tutors to perform the technique. Laparoscopy results in reduced tissue damage, due to minimal organ manipulation and surgical access hemostasis can be performed by several methods, such as electro-coagulation, clips, and intra and extracorporeal ligatures. A pre-tied ligature system, or endoloop, is a haemostatic technique comprised of a slipknot and knot pusher, which is inserted into the abdominal cavity through one of the laparoscopic ports. The aim of this study was to describe a novel OVE technique in cats, in which haemostasis was performed using miniloop, aimed at reducing the number of ports needed for knot tying.Material, Methods &amp; Results: Ten healthy not spayed female cats, aged 6 months to 5 years, were selected for this study. They were submitted to an OVE using miniloop as haemostasis method. Access to the peritoneal cavity was through two 5 mm ports on the midline of the ventral abdomen, 5 cm apart, with one immediately caudal to the umbilical scar and the other in between the last pair of teats. The first trocar was inserted at the caudal incision using the Hasson technique and a 5 mm zero-degree optics attached to a camera was introduced through it. The placement of the second access port was video assisted. For ovary exposure, the patients were positioned in lateral recumbency on the contralateral side to the ovary being removed. The miniloop was composed of a 2 mm diameter minitrocar, a 1.8 mm knot pusher, and a pre-tied slipknot. It was introduced percutaneously at the lateral abdominal wall. It was inserted attached to a pre-tied loop ligature. A Babcock forceps was used to guide the slipknot until it enveloped the ovarian vessels and the proximal part of the uterine horn. Subsequently, the knot was tightened with the aid of the knot pusher. A second miniligature was applied. The forceps was removed and a Metzenbaum scissors inserted to cut between the ligatures, releasing the ovary with the nylon ligature but keeping the PDS knot. It was performed at both ovary. Mean (±SD) surgical time was 44.8 min (± 13.4) and varied significantly (P = 0.0006) between animals, with the shortest time being 29 min and the longest 66 min. Positioning of the patients in lateral decubitus allowed for good ovarian exposure, without the need for excessive manipulation of the intestinal loops or other abdominal organs. Rupture of the suture thread was the only trans-operative complication observed and occurred in two animals. A second ligature (miniloop) was needed to ensure haemostasis. One cat showed eventration at the site of the caudal port on the second day post-operative.Discussion: The mean surgical time in the present study was lower than reported by some authors, but longer than anothers. Furthermore, the surgical time from this study is similar to that of other studies in cats in which haemostasis of the OAVC was achieved using bipolar electrocoagulation. Surgical team expertise is of outmost importance in minimizing complications and overcoming problems during videosurgical procedures in order to reduce surgical time, such as gas leakage, extensive incision, and difficulty in manipulating surgical instruments.

Microbial colonization around orthodontic ligature ties: An in-vivo study

Introduction: Fixed or removable orthodontic appliances impede oral hygiene and result in plaque accumulation. Studies have evaluated the effects of fixed orthodontic appliances on microbial flora and periodontal status, but only a few have evaluated the method of ligation as an additional factor. Aims and Objectives: To determine the amount of microbial colonization with different elastomeric ligation techniques. Material and Methods: Twenty subjects and a total of five ligature systems divided into five groups were chosen for the split mouth study. Group II and III (super slick ties and slide ligatures) were ligated over the premolars on the right side while Group IV and V (quick stick ties - angulated and easy to fit ties) were ligated over the premolars on the left side in both the arches. Group I (control) or stainless steel ties were made over the cuspids in the same manner. Elastomeric ligatures were removed after a period of 21 days and sent for culture. The amount of microbial colonies was then compared using stereomicroscope. Results: The amount of microbial colonization observed was statistically significant ( P Conclusion: Super slick elastomeric ligatures were found to have minimal microbial adhesion similar to that of stainless steel.

Static frictional resistance with the Slide low-friction elastomeric ligature system

Abstract Aim This ex-vivo study compared the static frictional resistance of a low-friction ligation system against a conventional elastomeric module, and studied the effect of storage in a simulated oral environment on the static frictional resistance of both ligation systems. Methods Eighty stainless steel brackets were tested by sliding along straight lengths of 0.018 inch round and 0.019 x 0.025 inch rectangular stainless steel wires ligated with either conventional elastomerics or the Slide system (Leone, Florence, Italy). During the tests the brackets and wires were lubricated with artificial saliva. A specially constructed jig assembly was used to hold the bracket and archwire securely. The jig was clamped in an Instron universal load testing machine. Crosshead speed was controlled via a microcomputer connected to the Instron machine. The static frictional forces at 0 degree bracket/wire angulation were measured for both systems, fresh from the pack and after storage in artificial saliva at 37 °C for 24 hours. Results The results of this investigation demonstrated that the Slide ligatures produced significantly lower static frictional resistance than conventional elastomeric modules in the fresh condition and after 24 hours of storage in a simulated oral environment (p &lt; 0.001). Storage for 24 hours in artificial saliva had no effect on the static frictional resistance of conventional elastomeric modules and the Slide system (p = 0.525). Conclusions The claim by the manufacturer that the Slide system produces lower frictional resistance than conventional elastomeric modules is upheld.

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.

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

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

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.

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.

The influence of the SPEED bracket's self-ligating design on force levels in tooth movement: A comparative in vitro study

In the SPEED bracket system the arch wire is retained in the arch wire slot by means of a built-in, escape-proof, flexible spring clip. Unlike the traditional edgewise bracket, it requires no ligature tie, thus ostensibly reducing the frictional force generated by the more-established elastomeric or steel-tie ligature systems. An in vitro study was designed to compare the level of force required to move four distinct arch wires a similar distance, on six occasions, through four ligated bracket systems and the self-ligated SPEED bracket. The results consistently demonstrated a significant decrease in the force level required for the SPEED bracket with all four arch wires when compared with elastomeric and steel-tie ligation in both metal and plastic bracket systems.

Acetylcholinesterase activity and its fast axonal transport in rabbit sciatic nerves during the recovery phase of experimental allergic neuritis.

Acetylcholinesterase (AChE) activity and its fast axonal transport were studied in rabbit sciatic nerves with a double ligature system during the recovery phase of experimental allergic neuritis (EAN), 6-9 days after the maximal symptoms, in order to obtain biochemical evidence of possible axonal damage in this primary demyelinating disease. The stationary AChE activity was significantly decreased, but the amount of the fast transported enzyme activity remained at the level of the controls. The velocity of the orthograde transport of AChE was slowed by about 15%, but this decrease was not statistically significant. Our results lend further support for the suggested neuronal damage in EAN, which can provide an explanation to the finding that the clinical symptoms in demyelinating diseases of the peripheral nervous system do not always correlate with the state of myelin.

Routine use of minute forces

In the SPEED bracket system the arch wire is retained in the arch wire slot by means of a built-in, escape-proof, flexible spring clip. Unlike the traditional edgewise bracket, it requires no ligature tie, thus ostensibly reducing the frictional force generated by the more-established elastomeric or steel-tie ligature systems. An in vitro study was designed to compare the level of force required to move four distinct arch wires a similar distance, on six occasions, through four ligated bracket systems and the self-ligated SPEED bracket. The results consistently demonstrated a significant decrease in the force level required for the SPEED bracket with all four arch wires when compared with elastomeric and steel-tie ligation in both metal and plastic bracket systems.