Bracket Slot Research Articles

Passive self-ligating metal brackets: evaluation of torque and slot measurements

New orthodontic bracket designs have been regularly developed. Their clinical performance depends on reliability of measures, among other factors. Objective: The aim of this study was to evaluate slot measures and torque angle of different passive self-ligating metal brackets, while comparing them with measures provided by manufacturers. Material and methods: Five different passive self-ligating metal bracket brands were selected (n = 10 each): Tellus EX, Tellus EX New, Damon Q, Easy Clip and ID-Logical. Bracket slots images were obtained with the aid of Starrett, MV300 Galileo Vision System. For slot digital measurement, Software M3 Metrology Reabout IV was used. Slot measures were evaluated in cervico-occlusal direction (slot height), buccolingual depth (in-out), and bottom-slot inclination (torque angle). Difference between obtained and provided measures was estimated and expressed as a percentage. Data were subjected to descriptive statistical analysis. Results: Most brackets evaluated by the present study revealed variation in both torque angle and slot measures which were confirmed to be greater than those provided by the manufacturer (Easy Clip, Damon Q and Tellus EX), except for two brackets (Tellus EX New and ID-Logical). The latter presented variation within normality with values accepted by ISO standards (± 1 degree and ± 1 mm variation). Conclusion: Most brackets assessed herein (Easy Clip, Damon Q and Tellus EX) presented variation in torque angle and slot measures. Tellus EX New and ID-Logical brackets remained within standards. Better standardization and control should be assumed by manufacturers in order to promote more reliability and predictability of the orthodontic treatment results.

Effect of different post materials and designs on upper central tooth torque and intrusion load: A finite element analysis study

The aim of this study was to examine the effects of post material type and the presence of ferrules on the torque and intrusion load of the upper central tooth using finite element analysis. The upper central tooth and surrounding tissues (cortical bone, cancellous bone, and periodontal ligament) were modelled in three dimensions using the Spaceclaim software. Five simulated models (SM) different modifications were made to this main model: metal cast post (SM1) and glass fiber post-core with zirconium crown and without a ferrule (SM2), metal cast (SM3) post and glass fiber post with a ferrule and zirconium crown (SM4) and only zirconium crown (SM5). In all five simulations, in order to simulate lingual root torque movement, a total load of 40grams was applied to the bracket slot as 20grams of force couples and in order to simulate intrusion movement, a load of 40grams was applied to the superior wall of the bracket slot. The stress caused by the applied loads on the root surfaces was determined using finite element analysis. Maximum principal stress (MPS) value was used in the comparison. The highest root surface MPS values for both intrusion and torque loads belonged to SM2 (3.864 and 0.379MPa, respectively). The presence of ferrules in both intrusion and torque loads reduced the stress by approximately half (from 3.864 to 2.004MPa). In all five models, the radicular area with higher stress was located in the cervical third on the lingual surface when both torque and intrusion loads were applied. The amount and localization of stress was affected by the type of post material. The variation in stress values between the materials remains within a safe range (0.099 and 3.87MPa), making both materials suitable for use under orthodontic forces.

Exploring bracket torque expression: A comparative in vitro study of new self-ligating bracket designs and archwire geometries

This in vitro study aimed to evaluate the torque expression efficiency when it is integrated into the bracket slot versus the bracket base. Additionally, the impact of archwire geometry (rectangular vs. rhomboid) on torque expression has been examined. The torque expression was evaluated in a full arch printed maxillary model, focusing on tooth #11, which was positioned within an alveolus filled with Typodont wax. Three different types of brackets were utilized: conventional metallic bracket (Minidiamond™), self-ligating bracket with torque in base (Damon Q2™), and a new self-ligating bracket design with torque in slot (Damon Ultima™). Two variations of archwires were used: rectangular and rhomboid stainless steel, measuring 0.019×0.025 inches and 0.019×0.0275 inches, respectively, from ORMCO™. The study included seven groups: six experimental groups and a control group, with 15 measurements in each group, totaling 105 torque measurements. Optical impressions were taken of the tooth's original position and its final position after torque expression. STL files were superimposed using GEOMAGIC software to calculate the percentage of torque expression. The self-ligating bracket with torque in slot (Damon Ultima™) shows significantly higher torque expression than the self-ligating bracket with torque in base (Damon Q2™) with a rectangular stainless steel archwire (P=0.00015). The Ultima™ bracket also demonstrates higher torque expression than both the Q2™ and conventional 22° brackets with a rhomboid stainless steel archwire (P<0.003). No significant difference in torque expression was found between the rectangular and rhomboid stainless steel archwires for any bracket group (P>0.05). The self-ligating bracket with torque in slot shows comparable torque expression effectiveness to the conventional bracket, outperforming the self-ligating bracket with torque in base. Archwire geometry does not significantly impact torque expression.

Effect of friction on levelling of the maxillary canine with NiTi superelastic wire - an in silico experiment using a finite element method

ABSTRACT Purpose To clarify the effect of friction on the levelling process using a NiTi superelastic wire, the levelling process was simulated using a finite element method. Materials and methods The maxillary right canine, which was intruded by 2 mm, was levelled using a 0.014 inch or 0.016 inch NiTi round wire. The wire was supported by two fixed brackets with 0.018 × 0.025 inch slots. The canine, alveolar bone, and bracket were rigid bodies, while the periodontal ligament (PDL) was a nonlinear elastic material. Kinetic friction was caused by contact forces acting on the wire and the bracket slot. Additionally, when the wire was securely ligated to the bracket slot, a constant frictional force caused by the ligation was directly applied to the wire. As the levelling force was applied to the canine, it moved by accumulating the initial tooth movement caused by elastic deformation of the PDL. Results In the case without friction caused by ligation, although the kinetic friction decreased the levelling force during the early levelling stage, the progress of levelling remained unchanged. In the case with friction caused by ligation, as the ligation friction increased, the levelling force decreased, reducing the levelling speed. Furthermore, the levelling process was impeded when the friction caused by ligation reached a critical value. Conclusion When using passive self-ligating brackets, the friction is caused only by levelling forces, which have almost no effect. When the wire is ligated securely to the bracket, additional friction is generated, hindering the levelling process.

Comparison of Friction Resistance Between Different Bracket Systems: An In Vitro Study

Introduction The efficiency of tooth movement associated with orthodontic sliding mechanics can be compromised by friction between archwire and tube or bracket slot. Orthodontic brackets and archwires are important constituents of an orthodontic appliance system. Friction is an uncontrolled variable of particular interest when continuous arch techniques are used to align and move teeth by way of sliding a tube or bracket along an arch. Aim and Objectives Comparison of frictional resistance between different bracket systems of 3M and MO brands in combination with different wires of 3M, MO, and G&amp;H brands. Evaluation of frictional resistance between two different types of bracket systems and different types of wire combinations. Materials and Methods Two types of bracket systems were used: metal bracket system and ceramic bracket system (3M and MO brands). Four different orthodontic wire alloys were used: stainless steel (SS), TMA, NiTi, and CuNiTi (3M, MO, and G&amp;H brands). A rectangular block made up of self-cure acrylic resin was designed to hold the bracket during the mechanical test. Each bracket base was glued to an acrylic block with cyanoacrylate glue. The wire segment was inserted into the bracket and was ligated passively with SS ligature wire. The bracket–wire combination was submitted to mechanical tests with a universal testing machine. One end of the acrylic block was mounted to the lower grip of the universal testing machine. The free end of the archwire was fixed to the upper grip of the universal testing machine. The friction which was generated between the wire and bracket was measured under dry conditions and at room temperature. The test wire was pulled through the bracket at a speed of 0.5 cm/min. The load cell registered a maximum force level. This data was stored in the computer and was submitted to statistical analysis, and parameter tests were applied. Results The highest mean friction resistance of 5.998 N was generated by group B2-E2 (ceramic bracket – MO + TMA archwire – MO). The lowest mean friction resistance of 2.552 N was generated by group A1-C1 (metal bracket – 3M + SS wire – 3M). There was a statistically significant difference between the friction generated by the metal bracket on SS archwire and the ceramic bracket on TMA archwire regardless of 3M or MO brand material ( p value &lt; .0001) and metal bracket ( p = .0004).

Biomechanical effects of anew crimpable gate spring combined with conventional rectangular archwires for torque adjustment of individual anterior teeth : Acomparative finite element study.

Precise root torque adjustment of anterior teeth is indispensable for optimizing dental esthetics and occlusal stability in orthodontics. The efficiency of traditional rectangular archwire manipulation within bracket slots seems to be limited. The crimpable gate spring, anovel device, has emerged as apromising alternative. Yet, there is apaucity of guidelines for its optimal clinical application. This study used finite element analysis (FEA) to investigate the biomechanical impact of the gate spring on torque adjustment of individual anterior teeth and to elucidate the most effective application strategy. AFEA model was constructed by amaxillary central incisor affixed with an edgewise bracket featuring a0.022 × 0.028 inch (in) slot. Arange of stainless steel rectangular archwires, in conjunction with agate spring, were modeled and simulated within the bracket slots. Acontrol group utilized aconventional rectangular wire devoid of agate spring. Palatal root moments were standardized to 9, 18, and 36 Nmm for both experimental and control groups. The gate spring significantly amplified palatal root movement, notably with the 0.019 × 0.025 in archwire. However, this was accompanied by an increase in stress on the tooth and periodontal ligament, particularly in the cervical regions. The synergistic use of a0.019 × 0.025 in rectangular archwire with agate spring in a0.022 × 0.028 in bracket slot was identified as most efficacious for torque control of individual anterior teeth. The gate spring is aviable auxiliary device for enhancing torque adjustment on individual teeth. However, caution is advised as excessive initial stress may concentrate in the cervical and apical regions of the periodontal ligament and tooth.

The Mechanical and Clinical Properties of Customized Orthodontic Bracket Systems-A Comprehensive Review.

The rise of computer-aided design and computer-aided manufacturing (CAD/CAM) and 3D printing technologies in orthodontics has revolutionized the development of customized labial and lingual bracket systems with a variety of materials, which offer potential advantages over traditional orthodontic brackets. To highlight the current state of knowledge regarding the mechanical and clinical properties of CAD/CAM and 3D-printed custom bracket systems, we conducted a comprehensive search across the PubMed, Embase, Cochrane Library, Web of Science, and Scopus databases to identify relevant articles published before April 2024. Mechanical (including fracture toughness, hardness, modulus of elasticity, frictional resistance, slot accuracy, torque transmission, and shear bond strength) and clinical (including treatment efficiency and duration, cost, and comfort) properties were compared between traditional and customized orthodontic bracket systems in the current review. Our findings suggest that customized brackets have the potential to increase bracket slot precision, reduce treatment time, and offer cost-efficiency. However, it is worth noting that the advantages and disadvantages of customized bracket systems vary depending on the bracket material and the manufacturing methods, warranting comprehensively controlled investigations in the future.

Comparative Analysis of Displacements and Stress Produced by Square and Rectangular Bracket Slot With Incremental Torque: A Finite Element Analysis Study.

This study aimed to perform a comparative analysis of stresses and displacements with incremental torque on the maxillary incisors and surrounding cortical bone using conventional metal brackets with rectangular slots and passive self-ligating brackets with square slots using finite element analysis (FEA). An in vitro FEA study was conducted, in which a three-dimensional (3D) model of the maxilla was built using ANSYS softwareversion 18 (ANSYS Inc., Canonsburg, PA). The conventional McLaughlin, Bennet, and Trevisi (MBT) bracket (3M Unitek, Monrovia, CA) of 0.022 × 0.028-inch slot with a 0.019 × 0.025-inch rectangular stainless steel (SS) archwire (model 1) was compared with the Pitts 21™ self-ligating bracket system (OC Orthodontics, McMinnville, OR) of 0.021 x 0.21-inch slot with a 0.020 × 0.020-inch square SS archwire (model 2) at incremental torques of 5°, 10°, 15°, and 20°. The von Mises stress was evaluated at the maxillary incisors and surrounding cortical bone. The torque moment, tipping angle, and displacement of the maxillary incisors were also measured and compared between the bracket systems. The highest torque expression of 13.8 N-mm was observed in model 2, compared to a torque expression of 10.68 N-mm in model 1. The torque expression increased in both models from 0°to 20°. There was a play of 6.2°at 20°torquein model 2, whereas it was 9.32°​​​​​​​play in model 1. The torque expressions were better for the lateral incisors than for the central incisors. Increased incremental torque was associated with increased proclination of the incisors, and this movement was more pronounced for the central incisor and model 1. Furthermore, it was revealed that the stresses on the cortical bone and teeth were higher in model 2 than in model 1. It was concluded that the Pitts 21™ passive self-ligating system produced better torque expression and less play with square SS archwire compared to conventional brackets with rectangular SS archwire.

Evaluation of dimensional accuracy and surface roughness of lingual bracket slot –An in vitro study

The paradigm shift with the increasing number of adults and teens seeking aesthetic options for orthodontic treatment led to the increased demand for lingual orthodontics. When it comes to size and slot dimensions, lingual brackets are very different from labial brackets.With the rise of lingual orthodontics in our everyday practice, it's more critical than ever for practitioners to understand these potential bracket size variations. The resistance to sliding mechanics can occur if the contact angle between the archwire and bracket increases, this creates the need for precise bracket slot dimension. The amount of friction varies proportionally to the accuracy of the dimensions and the roughness of the bracket slot.To evaluate the precision of commercially available orthodontic lingual bracket slots in inch dimensions with manufacturers’ published dimensions using a stereomicroscope and to compare the surface roughness of commercially available orthodontic lingual bracket slots using an atomic force microscope.Lingual brackets from four different manufacturers were taken for evaluation of slot dimensions. Twenty brackets of each manufacturer were randomly selected. Trinocular Stemi 2000 Stereo Zoom Microscope with Digital Camera (Carl Zeiss, Germany) was used for measurement of bracket slot dimensions. An atomic Force Microscope (AFM) (Nanoscope® IV Di digital instrument, California, USA) was used to evaluate the surface roughness of lingual bracket slots. Comparison of dimensions between mesial processes and comparison of dimensions between distal processes showed that the difference was only marginal with no significant statistic value. Statistically significant results proved that slot dimensions were not precise as per the manufacturer’s standards for given lingual brackets and were oversized for all bracket systems. Statistically insignificant results showed that the bracket systems were similar concerning the surface roughness of the bracket.The analyzed series of lingual bracket systems exhibited significant differences with manufacturers’ standards in slot dimension, which will clinically result in torque play. Lack of standardization of slot dimensions during the manufacturing process may be clinically associated with undesirable tooth positioning and movement; inferring that the bracket systems were similar concerning the surface roughness of the bracket slot.

A Stereo-Microscopic Study: In-Built Torque Comparison using MBT Prescription Brackets of Different Companies

Torsion in an "archwire" that forms a pair when it interacts with a "bracket slot" produces torque. The archwire moves the tooth through the torsional tension created in the activated state, depending on the degree of torsion, the size and quality of the wire, and the deformability of the bracket. The dimensions of the bracket hole may unintentionally vary when brackets are made. Therefore, the purpose of this study was to evaluate the accuracy of built-in torque from various manufacturers.  Objective:- To measure and analyse the built-in torque of the maxillary right canine brackets, maxillary right lateral canines, and maxillary right central incisors from commercially available bracket systems (JJ Orthodontics, American Orthodontics, Koden Orthodontics, Desires - Ozone series). The brackets will be measured in 0.022 inches.  Material and Method:- The sample was made up of three brackets from each company (maxillary central incisor, lateral incisor, and canine), the torque of which was measured in a dimension of 0.022 inches. Using a stereomicroscope, images were captured, measurements were made following operator calibration with IMAGE PROPLUS, and a digital readout was generated.  Results:- In practically every bracket, the built-in torque mean values were lower. The built-in torque levels were most similar to the American Orthodontics standard values.

Comparison of Alignment Duration Between 0.018” And 0.022” Slot Brackets in Non-Extraction Orthodontic Adult Patients: A Randomized Clinical Study

Comparison of Alignment Duration Between 0.018” And 0.022” Slot Brackets in Non-Extraction Orthodontic Adult Patients: A Randomized Clinical Study

Modified tucker: Simplifying your orthodontic practice

Orthodontic treatment often involves the use of nickel-titanium (NiTi) wires for initial leveling and alignment of teeth due to their unique properties. However, engaging these wires into bracket slots, especially in crowded or rotated teeth can be challenging. This article presents the development of a custom-made wire tucker aimed at simplifying the engagement process, reducing operator effort, and maintaining sterility in orthodontic procedures. The design, advantages, and practical applications of this modified instrument are discussed, highlighting its potential to enhance clinical efficiency and patient outcomes.

Nanotomographic Analysis of Orthodontic Molar Tubes for Direct Bonding

(1) Background: The most important part of an orthodontic attachment (bracket or tube) is the tube or slot for the insertion of the orthodontic wire. Aligning teeth along the archwire according to angular values preadjusted in the bracket slots (or tubes) requires a very precise size accordance between the archwires and slots. The aim of this study was to perform a nanotomographic analysis of the geometric features of molar tubes for direct bonding in terms of their dimensions and angles of their inner walls and analyze the presence of metallurgic imperfections. (2) Methods: Orthodontic tubes (n = 100) for upper right first molars from five different manufacturers (3M-Victory Series, Adenta-Bond Sing, Dentaurum-Ortho Cast M, GC-L LP, and ORMCO-Accent), 20 tubes each, were subjected to nanotomographic analysis. Measurements of the inner channel of the tubes, angles between the walls, and analysis of metallurgic imperfections were performed using high-resolution computed tomography. (3) Results: height measurements differed by 4–14% from ideal values declared by manufacturers, whereas the angles ranged from reducing by a maximum 1% comparing to values declared (hypodivergent walls) to increasing by a maximum 4.5% (divergent walls). (4) Conclusions: 1. The sizes of channels measured were slightly larger than those declared by manufacturers. 2. Slight deviations in wall parallelism and angles between the walls were found. 3. Some tubes were characterized by manufacturing defects of the metal. 4. Efforts should be made to further improve the production process of orthodontic attachments.

Evaluation of Stresses Generated with Two Different Self-Ligating Orthodontic Bracket Systems - A Finite Element Analysis.

To determine stresses generated in the posterior teeth region by two different self-ligating systems, 3M Unitek SmartClip and Damon Q Self-ligating brackets, using the finite element method (FEM). Computed tomography (CT) scan of maxilla was taken using Mimics software, and the Dicom data were imported into Hypermesh 13.0 software to convert it into a geometric model and then into FEM. Physical models of both the brackets were constructed and positioned on the teeth. Post archwire modeling, contact is defined between the bracket slot and 0.014" NiTi arch wire. The final assembled model was exported to ANSYS 12.1 for analysis, and 60 grams of load was applied at the ends of the arch wire. On using 0.014" CuNiTi in both the bracket systems, stresses generated on the root surface were found to be maximum on the first molar region, followed by the first premolar, second molar, canine, and second premolar regions. Comparison between the two bracket systems showed differences in the stresses generated, where higher stresses were generated at all regions in the Damon Q bracket system, except the inter-second premolar region. Maximum stresses were observed with the 3M Unitek SmartClip bracket system at the second premolar cervical region when compared to the Damon Q system. In both the cortical bone and cancellous bone, maximum stresses were observed at the second premolar cervical in the Damon Q bracket system region.

Hybrid Orthodontics for Aesthetic Deep Bite Correction—Case Series and General Clinical Considerations

Background: A range of psychosocial and aesthetic factors motivate patients to undergo orthodontic treatment. The appliance choice depends not only on the type of malocclusion, but also on the aesthetic and functional demands of the patients themselves. Nowadays, digital planning enables the manufacture of individualised and customised orthodontic appliances. However, the predictability of movements with aligner treatment has long been under discussion. This article illustrates, through a series of case reports, how a hybrid approach combining individualised aesthetic orthodontic appliances can improve the predictability of tooth movements, thereby providing additional tools for clinicians charged with choosing the best indicated and biomechanically advantageous technique. To this end, three patients with different malocclusions were treated via a hybrid approach involving clear aligners in the upper arch followed by lingual fixed appliances in the upper and lower arches. All patients were treated using ALIAS lingual PSL 0.018 × 0.018-inch slot brackets and in-house 3D-printed aligners. Findings: The hybrid approach combining aligners and fixed lingual appliances led to the successful resolution of all three complex cases in the series without prolonging treatment time. The superimpositions demonstrate the predictability of even traditionally difficult movements. In particular, the Alias PSL lingual system, used from the beginning, enabled good control of both the torque and inclination of the lower incisors. Conclusions: Combining clear aligners and fixed lingual appliances provides a highly efficient means of treating malocclusions aesthetically. In our cases, the aligners offset the lack of bite-plate effect from the lingual brackets and appliances, providing advantageous biomechanics for rotation correction and control of tip, torque and root movements. Understanding how to exploit the strengths of each appliance enables the clinician to treat adult patients efficaciously, efficiently and aesthetically.

Correlating Frictional Forces Generated by Different Bracket Types during Sliding and Surface Topography Using Scanning Electron Microscopy and Optical Profilometer.

The study aims to correlate the frictional forces (FF) of four different types of commercially available ceramic brackets to their surface topography. Two monocrystalline (MC) brackets (CLEAR™, Adanta, Germany; Inspire ICE™, Ormco, USA), one polycrystalline (PC) bracket (Symetri Clear™, Ormco, USA), one clear hybrid esthetic bracket (DISCREET™, Adanta, Germany), and a stainless-steel (SS) bracket (Victory™, 3M Unitek, USA) served as control. Both static friction (SF) and kinetic friction (KF) were recorded during sliding using an Instron universal machine in dry settings. The bracket slot surface topography was evaluated. A scanning electron microscope (SEM) and a profilometer machine were used for assessment before and after sliding. Frictional forces values during sliding were as follows in descending order; Inspire ICE™, CLEAR™, DISCREET™, Symetri Clear™, and, lastly, Victory™. Also, DISCREET™ scored the highest in surface roughness (Sa) values followed by Symetri Clear™. None of the correlations were statistically significant. Frictional forces produced during sliding were not always directly related to surface roughness. Monocrystalline ceramic brackets appeared to have the greatest FF and a low surface roughness. Furthermore, DISCREET™ scored a very low frictional value comparable to metal brackets yet showed the highest surface roughness. Metal brackets exhibited the greatest surface smoothness before sliding and the least SF. Predicting the FFs produced during sliding mechanics would help the practitioner while choosing the bracket system to be used, and while planning the treatment mechanics, how much force to deliver, and how much tooth movement to expect. How to cite this article: AlBadr AH, Talic NF. Correlating Frictional Forces Generated by Different Bracket Types during Sliding and Surface Topography Using Scanning Electron Microscopy and Optical Profilometer. J Contemp Dent Pract 2024;25(1):41-51.

A scanning electron microscopy investigation of the precision of three orthodontic bracket slot systems

ObjectiveOne of the most imprortant factors in achieving ideal teeth positions is the precision of the slot dimensions of orthodontic brackets into the archwires are inserted.This study aimed to assess the accuracy of the dimensions of orthodontic bracket slots and molar buccal tube apertures and to compare them with the specifications provided by the manufacturers.MethodA total of sixty brackets and ten molar buccal tubes with varying slot heights were examined using a scanning electron microscope from the mesial side. The dimensions and morphology of these bracket slots and buccal tubes apertures were assessed using the AutoCAD Software. A one-sample t-test was conducted to compare the measurements with the values provided by the manufacturer.ResultsThe findings of the present study indicated that the height of the measured bracket slots and buccal tube apertures dimensions were significantly larger than the actual dimensions and exhibiting divergent walls. On the other hand, the depth of the brackets slots showed significantly smaller values than the actual one.ConclusionA need for careful consideration when selecting a commercially accessible brand for everyday use is essential as certain materials may not meet acceptable standards.

Comparing Torque Transmission of Different Bracket Systems in Combination with Various Archwires Considering Play in the Bracket Slot: An In Vitro Study.

This study aims to examine the play between various archwires and bracket systems, exploring potential variations in angle values for specific torque and torque values for a given angle along different bracket systems. Therefore, seven brackets systems were evaluated in conjunction with different stainless steel archwires of varying dimensions (0.016″ × 0.022″, 0.018″ × 0.025″, and 0.019″ × 0.025″). Biomechanical behavior during torque development and transmission was assessed using a six-component force/torque sensor. Torque angles (5-45°) were specified with subsequent torque measurement, and the sequence was reversed by setting the torque (5-30 Nmm) and measuring the angle. A reference measurement with 0 Nmm torque served to evaluate bracket slot play. Bracket play (0 Nmm) during palatal load ranged between 20.06° and 32.50° for 0.016″ × 0.022″ wire, 12.83° and 21.11° for 0.018″ × 0.025″ wire, and 8.39° and 18.73° for 0.019″ × 0.025″ wire. The BioQuick® bracket exhibited the highest play, while Wave SL® and Damon® Q brackets demonstrated the lowest play (p < 0.001). Significant differences (p < 0.001) between the brackets were observed in the torque angles required to achieve torques of 5-20 Nmm. In summary, each bracket system has a different torque transmission, which is of great clinical importance in order to achieve correct torque transmission and avoid complications such as root resorption.

Incisor torque expression characteristics in two passive self-ligating brackets placed at different heights. A finite element investigation

ObjectiveThis study investigated torque expression in maxillary incisors using two passive self-ligating bracket types (Damon Q and Pitts 21) placed at different heights using the Finite element method. Materials and methodsTwo passive self-ligating brackets, Damon Q (Ormco, USA) and Pitts 21 (OC Orthodontics, USA) were 3D modeled using micro-computed tomography. Damon Q (0.022ˮ x 0.028″ slot size) and Pitts 21 (0.021ˮ x 0.021″ slot size) brackets were placed on a maxillary central incisor at predetermined vertical heights. Arch wires of size 0.019ˮ x 0.025″ stainless steel (Damon Q) and 0.020ˮ x 0.020” Titanium Molybdenum (Pitts 21) were placed in the bracket slots. ResultsPitts 21 brackets showed higher torquing moments at all bonding heights as compared to Damon Q brackets. The minimum torquing moment was 9.03Nmm at 5 mm for Damon Q and the maximum torquing moment was 14.92Nmm for Pitts 21 at a bracket bonding height of 8 mm. Total deformation for Pitts 21 at a height of 5 mm from the incisal edge was 0.61 × 10−6mm as compared to that of Damon Q which was 0.41 × 10−6mm. Lowest Von Mises stress values were at 27.07 MPa in Damon Q brackets at a bracket height of 5 mm from the incisal edge. Highest Von Mises stress values were 36.80 MPa for Pitts 21 brackets at a bracket height of 8 mm from the incisal edge. ConclusionPitts 21 brackets exhibited superior torquing characteristics compared to Damon Q. Total deformation in Pitts 21 was higher than Damon Q at all tested bracket bonding heights.

The Effectiveness of Different Bracket Slot Dimensions in Orthodontic Treatment

The Effectiveness of Different Bracket Slot Dimensions in Orthodontic Treatment