Friction and archwire engagement in contemporary self-ligating appliance systems : An in vitro comparison.

PURPOSE: The aim of this study was to compare classical friction (FR) in passive self-ligating brackets (P-SLBs), active self-ligating brackets (A-SLBs) and a traditional twin bracket, in vitro, and to identify the point of initiation of bracket-archwire engagement. METHODS: Nine bracket systems of 0.022 in slot size were FR tested: 5 P­SLB systems; 4 A­SLB systems; and a control group of twin brackets with elastomeric ligatures. Single upper right central incisor brackets were mounted on a custom metal fixture for testing. Straight sections of various round and rectangular nickel-titanium (NiTi) archwires (0.016, 0.018, 0.018â€¯× 0.018, 0.020â€¯× 0.020, 0.016â€¯× 0.022, 0.017â€¯× 0.025, 0.019â€¯× 0.025, and 0.021â€¯× 0.025 in) were ligated to the bracket and peak static FR (cN) was measured with an Instron Universal Testing Machine. Ten unique tests each utilizing a new bracket and new archwire were conducted for each group in the dry state. RESULTS: FR was significantly different between control, P­SLB and A­SLB systems (P < 0.001). P­SLB groups displayed no significant differences in FR between each other, regardless of archwire size. A­SLB groups did exhibit significant differences in FR between each other depending on both the bracket system and archwire size. Each A­SLB system tested possessed a distinctly different pattern of initiation of bracket-archwire engagement. CONCLUSIONS: FR between the archwire and bracket slot differs between P­SLB and A­SLB systems, with a distinct pattern of FR and bracket-archwire engagement for each A­SLB system. Understanding the different bracket-wire interactions of SLB systems should help orthodontic clinicians to plan effective and efficient biomechanics with the bracket system of their choice.

Comparative Evaluation of Two Bracket Systems' Bond Strength: Conventional and Self-Ligating.

Adhesion remains a key element in dentistry, whether approached in prosthetics, odontology, or orthodontics. It is a continuously researched aspect, as improved materials and adhesive methods keep emerging in the market. No orthodontic treatment can be effective without the proper adhesion strength of the bonded elements on the teeth. The objective of this research, in the broad context of self-ligating versus conventional brackets, was to compare active and passive self-ligating systems with a conventional one by conducting an in vitro study on human-extracted premolars. Shear bond strength tests were executed by means of an advanced materials-testing machine that generated maximum load and tensile strength values. The data obtained underwent statistical analysis with a statistical threshold of p < 0.05. The results regarding the statistical significance were acquired when comparing the passive self-ligating system with the active self-ligating and conventional systems (load-at-maximum-load mean 204.9, SD 91.09, and p < 0.05). In this study, the passive self-ligating bracket system appears to present increased shear bond strength.

Comparative evaluation of duration of extraction space closure and degree of root resorption with conventional and self-Ligation brackets.

Introduction: Determination of difference between conventional and passive self-ligating brackets (SLBs) in respect of extraction space closure, patient perception and root resorption. Material and Methods: Eighty patients were divided into four groups of 20 each with age-sex-matched control using a simple randomisation technique and allocation concealment with a closed opaque envelope method. Group 1 consisted of conventional brackets with Connecticut New Archwire (CNA) wire mushroom loop, group 2 consisted of conventional brackets with TAD (AbsoAnchor, Korea) supported retraction, group 3 consisted of passive SLB with CNA archwires (Libral Traders, India) mushroom loop and group 4 consisted of passive SLB brackets with TAD (AbsoAnchor, Korea) supported retraction. The rate of retraction, root resorption and patient satisfaction were assessed. All conventional brackets (Orthox, USA) and passive SLBs (CaptainOrtho, India) had 0.018 Roth prescriptions with a slot size of 0.018 × 0.025. Results: Retraction was the fastest in group 2 with a mean of 1.266 ± 0.14 mm/4 week and a duration of 23.40 weeks. Similarly, group 4 showed the most sluggish movement with a mean of 1.182 ± 0.80 mm/4 weeks with a total duration of 25 weeks; howeverdifferencesce among groups were not statistically significant (P = 0.470). Conclusion: SLBs have advantage of better patient comfort, less pain and reduced chairside time. Though the present study found increased treatment duration with SLB along with friction mechanics, refuting the previous claims of reduced friction with SLBs, however, the difference was not statistically significant and results have to be extrapolated with caution and experience considering other advantages of SLBs.

Comparison of transverse maxillary dental arch width changes with self-ligating and conventional brackets in patients requiring premolar extraction - A randomised clinical trial.

OBJECTIVE: The purpose of this study was to evaluate, the change in the transverse maxillary arch dimensions, in patients requiring all first premolar extractions when using Active and Passive Self-ligating brackets, and comparing them with Conventional brackets. MATERIALS AND METHODS: This study was a non-blinded randomised clinical trial, which consisted of 42 patients (21 males and 21 females) within the age group of 16-25 years, having bimaxillary protrusion. They were divided into three groups with 14 patients each. In Group 1 - Conventional brackets (3M Unitek), in Group 2 - Passive Self-ligation brackets: Smart Clip (3M Unitek), and in Group 3 - Active Self-ligation brackets: Empower AO (American Orthodontics) were bonded. All brackets had MBT prescription and 0.02" slot size. Dental study models were taken before the start of treatment and after six months of retraction. Inter-canine and intermolar widths were measured in all the three groups in the above mentioned stages. RESULTS: As compared to Conventional brackets, Self-ligating brackets (Passive and Active) showed greater increase in the transverse arch widths. Furthermore, between Passive and Active Self-ligating brackets, Passive Self-ligating brackets - Smart Clip (Group 2) showed a greater increment in the transverse arch dimensions, with an increase of 4.89mm in the inter-canine width and 3.4mm in intermolar width. CONCLUSION: Significant difference was found between Self-ligating brackets and the Conventional bracket system regarding maxillary arch width dimensional changes. Passive Self-ligating brackets - Smart Clip (Group 2) showed the highest and inter-molar width increase.

Tratamento da Classe II-1 subdivisão, utilizando miniparafuso extra-alveolar no izc e aparelhos autoligáveis passivos ­ relato de caso / Class II-1 subdivision treatment using extra-alveolar mini screw in izc and passive self-ligating brackets ­ case report

As más oclusões de Classe II de Angle, de natureza dento-alveolar ou esquelética moderada, podem ser tratadas com ou sem exodontias de pré-molares, utilizando diversos recursos para ancoragem. O advento dos miniparafusos possibilitou uma ancoragem esquelética na distalização de molares, anulando os efeitos colaterais indesejados, por meio de um procedimento minimamente invasivo. Os parafusos extra-alveolares eliminaram ainda o inconveniente do posicionamento do corpo dos parafusos entre as raízes, permitindo maiores movimentos sagitais, sem a necessidade de reposicionamento dos miniparafusos ou utilização de cursores. Esse fato aumentou a eficiência do tratamento nas correções sagitais e simplificou a mecânica ortodôntica. A associação desse recurso de ancoragem com os aparelhos autoligáveis passivos com prescrições variáveis reduzem a quantidade de consultas, os níveis de força aplicada, necessidade de dobras no arco e a dependência de colaboração do paciente. Objetivo: Relatar um caso clínico no qual foi utilizado parafuso extra-alveolar na crista-infrazigomática como recurso de ancoragem, associado a aparelhos autoligáveis passivos na correção da Classe II-1 subdivisão direita. Conclusão: A associação dos parafusos extra-alveolares com o sistema de aparelhos autoligáveis passivos com prescrições variadas se mostraram eficientes na correção da má oclusão de Classe II subdivisão (AU)

Abstract Introduction: Angle Class II dentoalveolar or moderate skeletal malocclusions can be treated with or without premolar extraction using a variety of anchoring features. The advent of mini-screws allowed skeletal anchorage in molar distalization, nullifying unwanted side effects through a minimally invasive procedure. The extra-alveolar screws also eliminated the inconvenience of positioning the body of the screws between the roots, enabling greater sagittal movements, dispensing replacement of the mini-screws or cursors use. This fact increased treatment efficiency of sagittal corrections and simplified orthodontic mechanics. The association of this anchorage feature with passive self-ligating brackets reduces the number of consultations, the levels of applied force, the need for arch bending, and dependence of patient's collaboration. Objective: To report a clinical case in which the extra-alveolar screw was used in the IZC as an anchorage resource, associated with passive self-ligating brackets for the correction of Class II-1 subdivision. Conclusion: The association of extra-alveolar screws with passive self-ligating brackets system proved to be efficient in Class II subdivision malocclusion correction. (AU)