ABSTRACT
Abstract Introduction Kinesio tape (KT), although frequently used in sports, is still a matter of debate, and the results of studies that evaluated its effects on muscle strength (MS) in athletes are still inconclusive and contradictory. Objective To evaluate the effect of a progressive KT tension protocol on knee MS in runners over an eight-week intervention. Methods Clinical trial involving 49 runners of both sexes randomized into two groups: KT (KT with progressive tension protocol) and placebo (KT without tension). The MS of knee flexors and extensors was evaluated by isokinetic dynamometer (60º/s and 90º/s) at four moments: (1) without KT; (2) with KT and without tension; (3) without KT (after 8 weeks after of intervention); (4) with KT and with tension (after 8 weeks after of intervention). Inter- and intra-group comparisons were made. The significance level adopted was 95% (p < 0.05). Results There were no significant differences in MS between the groups at any of the evaluated moments. There was a statistically significant difference in MS (60º/s) in both groups (KT and placebo) when comparing moments 4 and 2 for knee flexors, and in the placebo group between moments 4 and 2 and moments 4 and 3 for knee extensors. Conclusion The progressive tension protocol of KT was not able to intervene in the SM gain of knee flexors and extensors of runners in inter and intragroup comparisons.
Resumo Introdução A Kinesio tape (KT), apesar de muito utilizada na prática esportiva, ainda é motivo de debate e os resultados de estudos que avaliaram seus efeitos na força muscular (FM) em atletas ainda são inconclusivos e contraditórios. Objetivo Avaliar o efeito de um protocolo de tensão progressiva KT na FM do joelho em corredores ao longo de uma intervenção de oito semanas. Métodos Ensaio clínico envolvendo 49 corredores de ambos os sexos randomizados em dois grupos: KT (KT com protocolo de tensão progressiva) e placebo (KT sem tensão). A FM dos flexores e extensores do joelho foi avaliada por dinamômetro isocinético (60º/s e 90º/s) em quatro momentos: (1) sem KT; (2) com KT e sem tensão; (3) sem KT (após 8 semanas); (4) com KT e com tensão (pós-protocolo 8 semanas). Comparações inter e intragrupos foram feitas. O nível de significância adotado foi de 95% (p < 0,05). Resultados Não houve diferenças signi-ficativas na FM entre os grupos em nenhum dos momentos avaliados. Houve diferença estatisticamente significante na FM (60º/s) em ambos os grupos (KT e placebo, quando comparados os momentos 4 e 2 para flexores de joelho, e no grupo placebo entre os momentos 4 e 2 e os momentos 4 e 3 para extensores de joelho. Conclusão O protocolo de tensão progressiva de KT não foi capaz de intervir no ganho de FM de flexores e extensores de joelho de corredores em comparações inter e intragrupos.
Subject(s)
Humans , Torque , Muscle Strength , Athletes , KneeABSTRACT
Com o aumento da população brasileira e consequentemente o número de edêntulos realizando tratamentos reabilitadores com implantes dentários, se tornou frequente aparições de complicações como, por exemplo, sua fratura. O presente trabalho tem por objetivo apresentar as causas prováveis relacionadas a fratura de implante dentário, através de um relato de caso clínico onde pode-se avaliar a condição da fratura apresentada e como foi solucionada. Após a analise do caso clínico, foi constatado que o principal fator que levou a sua fratura foram as sobrecargas oclusais associadas ao mal posicionamento e a qualidade do implante antigo. A partir disso, conclui-se que é de extrema importância o cirurgião dentista estar ciente de todas as possíveis complicações acerca do implante dentário, afim de realizar um bom planejamento cirúrgico diminuindo a taxa de insucesso levando a um bom prognóstico.
With the increase of the Brazilian population and, consequently, the number of edentulous individuals undergoing rehabilitation treatmentes with dental implants, the appearance of complications such as, for example, their fracture has become frequent. The present work aims to presente the probable causes related to dental implant fracture, trough a clinical case report where the condition of the fracture presented and how it was resolved can be evaluated. After analyzing the clinical case, it was found that de main factor that led to its fracture were the occlusal overloads associated with poor positioning and the quality of the old implant. From this , it is concluded that it is extremely important for the dental surgeon to be aware of all possible complications regarding the dental implant, in order to carry out a good surgical planning, reducing the failure rate, leading to a good prognosis.
Con el aumento de la población brasileña y, en consecuencia, del número de personas edéntulas que se someten a tratamientos de rehabilitación con implantes dentales, las complicaciones, como las fracturas, se han vuelto comunes. El presente trabajo tiene como objetivo presentar las probables causas relacionadas con la fractura de implantes dentales, a través del reporte de un caso clínico, donde se puede evaluar la condición de la fractura presentada y la forma en que fue resuelta. Tras analizar el caso clínico, se comprobó que el principal factor que condujo a la fractura fue la sobrecarga oclusal asociada a una mala colocación y a la calidad del implante antiguo. Esto lleva a la conclusión de que es muy importante que el cirujano dental conozca todas las posibles complicaciones de los implantes dentales, para realizar una buena planificación quirúrgica, reduciendo así la tasa de fracasos y consiguiendo un buen pronóstico.
Subject(s)
Humans , Male , Middle Aged , Prostheses and Implants , Dental Implants , Causality , Bruxism/complications , Clinical Diagnosis/education , Osseointegration , Torque , Dental Implantation, Endosseous/instrumentation , Dentists/education , Fractures, BoneABSTRACT
Based on the biomechanical mechanism of human upper limb, the disadvantages of traditional rehabilitation training and the current status of upper limb rehabilitation robot, a six degree of freedom, flexible adjustment, wearable upper limb rehabilitation exoskeleton design scheme is proposed. Firstly, the mechanics of each joint of the upper limb is analyzed, and the virtual prototype design of the whole mechanical structure of the upper limb rehabilitation wearable exoskeleton is carried out by using CATIA three-dimensional software. The tooth transmission of the forearm and the upper arm single row four point contact ball bearing with internal/external rotation and the shoulder flexible passive adjustment mechanism (viscoelastic damper) are innovatively designed. Then, the joints of the upper limb rehabilitation exoskeleton are analyzed, theoretical analysis and calculation of the driving torque, the selection of the motor and gearbox of each driving joint are carried out. Finally, the whole finite element analysis of the upper limb exoskeleton is carried out. The research and experimental results showed that the design scheme of the upper limb exoskeleton assist structure is highly feasible, which can help the patients with upper limb paralysis and motor dysfunction self-rehabilitation.
Subject(s)
Humans , Biomechanical Phenomena , Exoskeleton Device , Robotics , Stroke Rehabilitation , Torque , Upper Extremity , Wearable Electronic DevicesABSTRACT
The series of YY/T 0987 standards converted from the corresponding ASTM (American Society for Testing and Materials) standards regulate the marking medical devices and testing methods for passive implants in the magnetic resonance environment. Along with the advancement of scientific cognition and the development of technology, the ASTM continuously amends and updates standards. This article studies the new version of ASTM standards and analyzes the advancing parts newly added as compared to the current YY/T 0987-2016 standard and eventually pinpoints some problems that remained to be solved. Except for the standard for image artifacts, this study found out that other standards had also been constantly updated, such as the standard of ASTM F2503 for marking medical devices extends its referenced documents and adds some ISO standards in, meanwhile, the test method on magnetically induced displacement force, radio frequency induced heating and magnetically induced torque also had been significantly adjusted and improved accordingly. This article recommends that domestic standards need to keep pace with the latest edition of ASTM F standards and to supplement new research achievements timely, just in order to provide a better normalization, guidance and support to the development of Chinese passive implants industry.
Subject(s)
Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Prostheses and Implants , Radio Waves , Torque , United StatesABSTRACT
Objetivo: Describir las fallas en diferentes sistemas de implantes al ser sometidos a fuerzas de torsión creciente, de- terminar el torque en el cual aparece un daño medible en el implante o alguno de sus componentes y especificar la falla más frecuente. Materiales y métodos: Se realizó un estudio experi- mental in vitro. Se utilizaron 88 implantes agrupados según diseño y marca comercial (Federa, Rosterdent, Biomet 3i, Tree-Oss, B&W, ML) en 11 grupos de 8 implantes cada uno. Éstos fueron inmovilizados en acrílico y fijados en una pren- sa. Se aplicó una fuerza de torsión creciente con torquímetro de precisión digital hasta la aparición de alguna falla en el implante o sus componentes. Se registró el torque en el que se produjo la falla. Se realizó estadística descriptiva para el análisis de datos. Resultados: El 100% de los implantes o alguno de sus componentes mostraron una falla detectable al ser sometidos a fuerzas de torsión creciente (rango de torque: 83,5 Ncm im- plante con conexión cono morse 8 grados a 384 Ncm implan- te de conexión interna sin montar). El torque promedio más bajo en el que aparecieron los daños fue 103,75 (±8,08) Ncm para implantes de conexión interna tipo cono morse, mientras que el más alto fue 279,87 (±89,73) Ncm para implantes de conexión interna sin montar. La falla más frecuente (28,4%) fue la fractura del tornillo del portaimplante y falseo del hexá- gono externo simultáneamente. Conclusión: Las fallas detectables a fuerzas de torsión creciente ocurrieron entre 83,5 Ncm y 384 Ncm. La falla rei-terada fue la fractura del tornillo del portaimplante y falseo del hexágono simultáneamente (AU)
Aim: To describe the failures in different implant sys- tems when subjected to increasing torsional forces, deter- mine the torque at which measurable damage occurs to the implant or one of its components, and determine the most frequent failure. Materials and methods: This was an experimental in vitro study. A total 88 implants were used, grouped accord- ing to design and trademark (Federa, Rosterdent, Biomet 3i, Tree-Oss, B&W, ML) into 11 groups of 8 implants each. The implants were immobilized in Duralay acrylic and fixed in a vice. Increasing torsional force was applied with a digital pre- cision torque wrench until the occurrence of any failure in the implants or their components. The torque at which the failure occurred was recorded. Descriptive statistics were performed for data analysis. Results: 100% of the implants or any of their compo- nents showed a detectable failure when subjected to increas- ing torsional forces (force range: 83.5 Ncm in an implant with 8-degree Morse taper connection to 384 Ncm in an implant with unmounted internal connection). The lowest average torque at which damage occurred was 103.75 (±8.08) Ncm for conical implants with Morse internal connection, while the highest was 279.87 (±89.73) Ncm for implant with unmounted internal connection. The most frequent failure (28.4%) was fracture of the implant retaining screw and distortion of the external hexagon simultaneously (AU)
Subject(s)
Tensile Strength , Dental Implants , Torsion, Mechanical , In Vitro Techniques , Dental Restoration Failure , TorqueABSTRACT
The presence of severe dynamic knee valgus in asymptomatic women may be a factor related to future complaints of pain in this joint. The aim of this study is to correlate the strength levels of hip and trunk stabilizer muscles with knee valgus angles, pelvic and trunk tilt in asymptomatic young women. 22 young women with no history of lower limb pain or injury participated in this study. In the first visit to the laboratory, the volunteers performed anamnesis, kinematic evaluation of the dynamic knee valgus angle, pelvic and trunk tilt. Afterwards, familiarization with muscle strength tests was made. On the second day, the evaluation of the maximal isometric muscle strength of the hip stabilizer muscles (lateral rotators, hip abductors and extensors) and trunk extensors was performed, using a hand dynamometer. For analysis of muscle strength data, the joint torque peak was used and, in relation to the kinematic data, the knee projection angles in the frontal plane, pelvis and trunk tilt, through the Kinovea software. Pearson's Correlation test showed no relationship between the hip and trunk muscle torque and the kinematic angles during the frontal and lateral step down. The muscle torque of the hip stabilizers and trunk extensors are not related to the movement pattern of the volunteers during the step down.(AU)
O valgo dinâmico de joelho em mulheres assintomáticas pode ser um fator de risco relacionado com queixas futuras de dor nessa articulação. O objetivo deste estudo é investigar a relação entre torque articular da musculatura estabilizadora do quadril e tronco com a cinemática do teste step down em mulheres jovens assintomáticas. Participaram deste estudo 22 mulheres, com idade média de 22,5 anos (±2,06), sem histórico de dor ou lesão em membros inferiores. Na primeira visita ao laboratório, as voluntárias realizaram anamnese, avaliação cinemática durante o teste step down frontal e lateral. No segundo dia, foi realizada a avalia ção do torque articular isométrico máximo de rotação lateral, abdução e extensão do quadril e extensão de tronco, utilizando um dinamometro manual. Para análise dos dados, foi utilizado o pico de torque articular dos movimentos avaliados e em relação aos dados cinemáticos, foi calculado os ângulos de projeção de joelho no plano frontal, inclinação da pelve e tronco, por meio do software Kinovea. O teste de Correlação de Pearson não mostrou relação entre o torque muscular de quadril e tronco com os ângulos cinemáticos durante o step down frontal e lateral. Portanto, concluímos que o torque muscular máximo dos estabilizadores lombo pélvicos não estão correlacionados com o padrão de movimento cinemático durante o teste step down.(AU)
Subject(s)
Humans , Female , Young Adult , Women , Biomechanical Phenomena , Physical Therapy Modalities , Muscle Strength Dynamometer , Young Adult , Knee , Pain , Rotation , Wounds and Injuries , Torque , Muscle Strength , Joints , Medical History Taking , Movement , MusclesABSTRACT
Objetivo: O objetivo do presente trabalho foi avaliar a resistência à fadiga cíclica e torcional de instrumentos rotatórios de níquel-titânio com secções transversais semelhantes e confeccionados com diferentes tipos de tratamentos térmicos: Hyflex CM (HCM 25/.06), Vortex Blue (VB 25/.06), Sequence Rotary File (SRF 25/.06) e EdgeSequel (EDF 25/.06) (n=20). Métodos: O teste de fadiga cíclica avaliou o tempo e o número de ciclos para a fratura (NCF) dos instrumentos em canal artificial com 60° de curvatura e 5mm de raio (n=10). O teste de torção avaliou o torque máximo e a deflexão angular para a fratura dos 3mm da ponta dos instrumentos (n=10). Após o teste de torção e de fadiga cíclica, os instrumentos foram avaliados em microscopia eletrônica de varredura (MEV) (n=10). Os dados foram analisados empregando-se os testes ANOVA e de Tukey, sendo selecionado um nível de significância de 5%. Resultados: HCM apresentou o maior tempo e NCF entre todos os instrumentos avaliados (p<0,05). O SRF apresentou um tempo semelhante (p>0,05) e menor NCF (p<0,05) do que o VB. Em relação ao teste torcional, o HCM apresentou menor valor de torque e maior deflexão angular entre os grupos avaliados (p<0,05). Não houve diferenças significativas entre VB, SRF e EDF em relação à deflexão angular (p>0,05). Conclusão: O HCM apresentou maior resistência à fadiga cíclica e deflexão angular. Entretanto, o VB apresentou maior resistência torcional para a fratura (AU).
Objective: The aim of this study was to evaluate the cyclic and torsional fatigue resistance of Nickel-Titanium rotary instruments with similar cross-sectional design and manufactured by different thermal treatments: Hyflex CM (HCM 25/.06) Vortex Blue (VB 25/.06), Sequence Rotary File (SRF 25/.06) and EdgeSequel (EDF 25/.06) (n=20). Material and Methods: Cyclic fatigue test evaluated the time and number of cycles to failure (NCF) in an artificial stainless steel canal with 60° and 5-mm radius of curvature (n=10). The torsional test (ISO 3630-1) evaluated he maximum torque and distortion angle to failure at 3 mm from the tip (n=10). After the torsional and cyclic fatigue test the instruments were evaluated by scanning electron microscope (SEM). Data were analyzed using one-way ANOVA and Tukey tests, and the level of significance was set at 5%. Results: The HCM presented the longest time and highest NCF to fatigue than all the groups (P<0.05). The SRF presented similar time (P>0.05) and lower NCF (P<0.05) to fatigue than VB. Regarding to the torsional test, HCM presented the lowest torque load and the highest distortion angle of all the groups (P<0.05). No significant difference was found among VB, SRF and EDF regarding the distortion angle (P>0.05). Conclusion: The HCM presented the highest cyclic fatigue resistance and distortion angle to failure. However, the VB showed higher torsional load to failure. (AU).
Subject(s)
Microscopy, Electron, Scanning , Torque , Dental Instruments , Endodontics , Titanium , Analysis of Variance , Fatigue , NickelABSTRACT
Abstract Background: The study of functional impact of delayed onset muscle soreness has been limited to describe the decline on maximal isometric contraction, but muscular work and time to peak torque has not been examined yet. Purpose: To describe the changes induced by a session of lengthening contractions on muscle performance and delayed onset muscle soreness (DOMS). Methods: A quasi-experimental study was conducted in the Institutional laboratory; Twenty healthy men; mean age 21 SD 0.34 were recruited, all subjects performed 200 lengthening contractions of the quadriceps at 120°/s. Isometric and isokinetic peak torque, muscular work, time to peak torque, DOMS and creatine kinase activity were assessed at baseline, 48 h and 96 h post-exercise. The muscle performance was assessed with an isokinetic dynamometer and DOMS with a visual analog scale (VAS). Results: Relative to baseline, isometric and isokinetic peak torque and muscular work decreased in ~30% at 48 h post-exercise; delayed onset muscle soreness increased ~300%, which remained at 96 h post-exercise. Conclusions: These reflect that the decline in muscular performance is due to the changes in peak torque and muscular work, which has greater implications on muscle function. No changes were detected in time to peak torque. The alterations in muscular performance variables are accompanied by delayed onset muscle soreness which has also a negative impact on force production (29% of the drop on peak torque is explain by soreness intensity).
Resumen Introducción: Los estudios de impacto funcional del dolor muscular de aparición tardía (DMAT) se han limitado a describir la disminución de la contracción isométrica máxima, pero aún no se ha examinado el trabajo muscular y el tiempo del torque máximo. Objetivo: Describir los cambios inducidos por una sesión de ejercicio excéntrico sobre el rendimiento muscular y DMAT. Método: se realizó un estudio cuasi-experimental, los participantes fueron veinte hombres sanos; edad media 21 DE 0,34, todos los sujetos realizaron 200 contracciones excéntricas del cuádriceps a 120°/s. Se evaluó el torque pico isométrico e isocinético, el trabajo muscular, el tiempo hasta el torque máximo, DMAT y la actividad de la creatina quinasa al inicio, 48 h y 96 h después del ejercicio, el rendimiento muscular se evaluó con un dinamómetro isocinético y DOMS con una escala análoga visual (EAV). Resultados: en relación con la línea de base, el torque pico isométrico e isocinético y el trabajo muscular disminuyeron en ~ 30 % a las 48 h post-ejercicio; El dolor muscular de aparición tardía aumentó ~300 %, que permaneció 96 h después del ejercicio. Conclusiones: los resultados reflejan que la disminución del rendimiento muscular se debe a los cambios en el torque pico y trabajo muscular, lo que tiene mayores implicaciones en la función muscular. No se detectaron cambios en el tiempo hasta el torque máximo. Las alteraciones en las variables de rendimiento muscular se acompañan de DMAT que también tiene un impacto negativo en la producción de fuerza (el 29 % de la caída en el torque máximo se explica por la intensidad del dolor).
Subject(s)
Humans , Male , Adult , Myalgia , Physical Functional Performance , Musculoskeletal System , Torque , Creatine Kinase , Muscle Strength Dynamometer , Isometric Contraction , Isotonic ContractionABSTRACT
SUMMARY: The purpose of this study was to investigate the effect of age on peak torque (PT) relative strength measures of knee extensors (KE) and knee flexors (KF), bilateral strength ratio (Q:Q, H:H), and ipsilateral strength ratio (H:Q) in youth elite male football players.Elite male players (n = 70) from four age categories (U16: n = 20, U17: n = 20, U19: n = 15, U21: n = 15) performed isokinetic strength tests using a Cybex dynamometer. Results show a significant effect of age on PTKE (F3,142 = 4.54, p = 0.005, = 0.09) and PTKF (age: F3,142 = 3.07, p = 0.030, = 0.06). No significant effect of age on unilateral (F3,142 = 1.05, p = 0.375, = 0.02) or ipsilateral strength ratio (F3,142 = 2.63, p = 0.053, = 0.06) was found. Results revealed significant differences in PTKE for nondominant limbs between U16 and U21. Higher bilateral differences were detected for flexors (H:H = 7.94-11.47 %, Q:Q = 7.97-9.29 %) compared to extensors. Our study showed that 17-year-old players have levels of strength similar to U19 players. A higher bilateral difference of knee flexors than extensors was found, suggesting that more attention should be paid to knee flexors. No effect of laterality was found for strength and strength asymmetries. Future research should also focus on ipsilateral strength ratio in late stage of maturation.
RESUMEN: El objetivo de este estudio fue investigar el efecto de la edad en las medidas de fuerza relativa de torque máximo (TM) de los extensores de rodilla (ER) y flexores de rodilla (FR), la relación de fuerza bilateral (Q: Q, H: H) y la relación de fuerza ipsilateral (H: Q) en jugadores de fútbol masculino de élite en 70 sujetos de cuatro categorías de edad (U16: n = 20, U17: n = 20, U19: n = 15, U21: n = 15). Se realizaron pruebas de fuerza isocinética utilizando un dinamómetro Cybex. Los resultados mos- traron un efecto significativo de la edad en TMER (F3,142 = 4,54, p = 0,005, = 0,09) y TMFR (edad: age: F3,142 = 3,07, p = 0,030, = 0,06). No se observó efecto significativo alguno de la edad sobre la fuerza unilateral (F3,142 = 1,05, p = 0,375, = 0,02) o relación de fuerza ipsilateral (F3,142 = 2,63, p = 0,053, = 0,06). Los resultados indicaron diferencias significativas en TMER para miembros no dominantes entre U16 y U21. Se detectaron mayo- res diferencias bilaterales para los flexores (H:H = 7,94-11,47%, Q:Q = 7,97-9,29 %) en comparación con los extensores. Nues- tro estudio mostró que los jugadores de 17 años tienen niveles de fuerza similares a la de los jugadores sub-19. Se observó una mayor diferencia bilateral de flexores de rodilla que de extensores, lo que sugiere que se debe prestar más atención a los flexores de rodilla. No se encontró un efecto de lateralidad para fuerza y asimetrías de fuerza. Los estudios futuros también deben centrarse en la relación de fuerza ipsilateral en la etapa tardía de maduración.
Subject(s)
Humans , Male , Adolescent , Soccer , Muscle Strength/physiology , Kinetics , Cross-Sectional Studies , Age Factors , Torque , Knee Joint , Functional LateralityABSTRACT
Abstrac The aim of the present study was to evaluate the cyclic fatigue, torsional resistance and surface roughness of Reciproc R25 instruments in four different situations, namely as new instruments and as instruments tested after clinical preparation of one, two or three maxillary molars with four root canals. The total time required to perform each root canal preparation was recorded. Cyclic fatigue resistance was determined by the time to fracture using a customized testing device (n = 10 per group). The torsional test evaluated the torque and angle of rotation to failure according to ISO 3630-1 (n = 10 per group). The roughness of the working parts of new and used instruments was evaluated with a profilometer (n = 5 per group). Statistical analysis was performed using one-way ANOVA and Tukey's test. The level of significance was set at 5%. No fractures or deformations were observed after clinical use. Higher preparation time was needed during the third use of the instruments for all root canals (p < 0.05). There were no significant differences among the groups in regard to either cyclic fatigue or torsional resistance (p > 0.05). Regarding the roughness measurements, groove depth was higher on new and one- versus two- or three-maxillary-molar-prepared instruments (p < 0.05). It can be concluded that the clinical use of Reciproc instruments increased preparation time and decreased surface roughness. However, clinical use did not affect the cyclic fatigue or torsional resistance of the Reciproc instruments.
Subject(s)
Titanium , Root Canal Preparation , Stress, Mechanical , Materials Testing , Torque , Dental Instruments , Equipment DesignABSTRACT
ABSTRACT Objective: Assess the influence of mono- and bicortical anchorage and diameter of mini-implants (MIs) on the primary stability of these devices. Methods: 60 self-drilling MIs were distributed in six groups according to diameter (1.5mm, 1.8mm or 2.0mm) and type of anchorage (monocortical and bicortical) in bovine rib. The primary stability was evaluated by insertion torque, micromobility and pull-out strength tests. ANOVA and/or Tukey analysis were used to conduct intergroup comparisons (p< 0.05). Non-parametric statistics (Kruskal-Wallis and Mann-Whitney) were performed when normality was not found (p< 0.05). Results: MIs with larger diameters and bicortical anchorage showed greater primary stability regarding insertion torque (p< 0.05) and micromobility (p< 0.05). Only MI diameter had an effect on the pull-out strength test. Larger diameter MIs presented better retention in pull-out strength tests (p< 0.001), regardless of mono- or bicortical anchorage. Conclusions: MI primary stability is dependent on its diameter and type of anchorage. Bicortical anchorage showed greater stability when compared with monocortical anchorage, independently of other variables.
RESUMO Objetivo: Avaliar a influência da ancoragem mono e bicortical e do diâmetro dos mini-implantes (MIs) na estabilidade primária desses dispositivos. Métodos: 60 MIs autoperfurantes foram distribuídos em seis grupos, de acordo com o diâmetro (1,5 mm, 1,8 mm ou 2,0 mm) e tipo de ancoragem (monocortical e bicortical), e inseridos em costela bovina. A estabilidade primária foi avaliada pelos testes de torque de inserção, micromobilidade e resistência à tração. ANOVA e/ou análise de Tukey foram usadas para realizar comparações intergrupos (p< 0,05). Estatística não paramétrica (Kruskal-Wallis e Mann-Whitney) foi realizada quando a normalidade não foi encontrada (p< 0,05). Resultados: MIs com diâmetros maiores e ancorados bicorticalmente apresentaram maior estabilidade primária em relação ao torque de inserção (p< 0,05) e micromobilidade (p< 0,05). Apenas o diâmetro do MI influenciou os resultados do teste de resistência à tração. MIs de maior diâmetro apresentaram melhor retenção nos testes de resistência à tração (p< 0,001), independentemente da ancoragem mono ou bicortical. Conclusões: a estabilidade primária do MI é dependente de seu diâmetro e tipo de ancoragem. A ancoragem bicortical apresentou maior estabilidade quando comparada à ancoragem monocortical, independentemente das demais variáveis.
Subject(s)
Humans , Cattle , Dental Implants , Orthodontic Anchorage Procedures , Palate , Palatal Expansion Technique , TorqueABSTRACT
ABSTRACT Introduction: Shorter miniscrew implants (MSIs) are needed to make orthodontics more effective and efficient. Objective: To evaluate the stability, insertion torque, removal torque and pain associated with 3 mm long MSIs placed in humans by a novice clinician. Methods: 82 MSIs were placed in the buccal maxillae of 26 adults. Pairs of adjacent implants were immediately loaded with 100g. Subjects were recalled after 1, 3, 5, and 8 weeks to verify stability and complete questionnaires pertaining to MSI-related pain and discomfort. Results: The overall failure rate was 32.9%. The anterior and posterior MSIs failed 35.7% and 30.0% of the time, respectively. Excluding the 10 MSIs (12.2%) that were traumatically dislodged, the failure rates in the anterior and posterior sites were 30.1% and 15.2%, respectively; the overall primary failure rate was 23.6%. Failures were significantly (p= 0.010) greater (46.3% vs 19.5%) among the first 41 MSIs than the last 41 MSIs that were placed. Excluding the traumatically lost MSIs, the failures occurred on or before day 42. Subjects experienced very low pain (2.2% of maximum) and discomfort (5.5% of maximum) during the first week only. Conclusions: Shorter 3 mm MSIs placed by a novice operator are highly likely to fail. However, failure rates can be substantially decreased over time with the placement of more MSIs. Pain and discomfort experienced after placing 3 mm MSIs is minimal and temporary.
RESUMO Introdução: Mini-implantes (MIs) mais curtos são necessários para uma Ortodontia mais eficiente e efetiva. Objetivo: Avaliar a estabilidade, torque de inserção e de remoção e dor associada a MIs de 3mm instalados em humanos por um ortodontista principiante. Métodos: 82 MIs foram instalados na região vestibular da arcada superior de 26 adultos. Pares de mini-implantes adjacente receberam carga imediata de 100g. Após 1, 3, 5 e 8 semanas, os pacientes foram reavaliados para verificar a estabilidade e preencher um questionário sobre a dor e o desconforto relacionados aos MIs. Resultados: A taxa geral de falhas foi de 32,9%, sendo de 35,7% para os MIs anteriores e 30% para os MIs posteriores. Excluindo os 10 MIs que foram perdidos por trauma (12,2%), a taxa de falha nas regiões anterior e posterior foram de 30,1% e 15,2%, respectivamente e ocorreram no 420 dia ou antes. A taxa geral de falha primária foi de 23,6%. A taxa de falha foi significativamente maior (p=0,010) nos primeiros 41 MIs do que nos 41 últimos (46,3% vs. 19,5%). As experiências relacionadas à dor foram baixas (2,2% máximo), assim como ao desconforto (5,5% máximo) durante a primeira semana. Conclusão: MIs de 3mm instalados por um novato são mais propensos a falhas. Porém, as taxas de falha podem diminuir substancialmente com a instalação de mais MIs com o decorrer do tempo. A dor e o desconforto após a instalação desses dispositivos são mínimos e temporários.
Subject(s)
Humans , Adult , Bone Screws , Dental Implants , Orthodontic Anchorage Procedures , Dental Implants/adverse effects , Feasibility Studies , Dental Prosthesis, Implant-Supported , Torque , Dental Implantation, Endosseous , Maxilla/surgeryABSTRACT
Objectives: With regard to the prevalence of abutment screw loosening (SL) and bone height reduction, particularly in the posterior regions of the jaws, as well as the contradictory issue of applying short implants instead of surgeries, along with all preparations associated with longer implants, the present study aimed to compare the amount of torque loss in short implants with increased vertical cantilever abutments and standard ones. Material and Methods: In this experimental study, a total number of 20 implants (MegaGen Implant Co., Ltd, South Korea) with 4.5 mm diameter including 10 short implants (7 mm) and 10 standard ones (10 mm) were utilized. Using a surveyor, fixtures were perpendicularly mounted in 13×34 mm resin for short implants and 19×34 mm resin for standard ones. The abutments of the same height but different cuff heights (2.5 mm for the standard implants and 5.5 mm for the short ones) were then tightened with 30 N.cm, via a digital torque meter. To compensate the settling effect, the abutment screw was re-tightened with 30 N.cm after 10 min. Upon applying 500,000 cycles at 75 N.cm and 1 Hz along the longitudinal axis on each sample, blind reverse torque value (RTV) was measured with a digital torque meter. The data were finally analyzed using Student's t-test. Results:Both groups experienced torque loss, but there was no statistically significant difference between the case and control groups in terms of abutment SL (p = 0451). Conclusion: Short implants seem to be a good mechanical alternative in emergencies with respect to torque loss and abutment SL. (AU)
Objetivos: Considerando a prevalência de afrouxamento de parafuso dos pilares, redução da altura óssea especialmente nas regiões posteriores, a questão contraditória da aplicação de implantes curtos em vez de cirurgias e todos os preparos associados a implantes mais longos, este estudo buscou comparar implantes curtos com pilares cantilever verticais aumentados e implantes padrão na quantidade de perda de torque. Material e métodos: Neste estudo experimental, foram utilizados 20 implantes (Megagen, Coreia do Sul) com diâmetro de 4,5 mm, incluindo 10 implantes curtos (7 mm) e 10 implantes padrão (10 mm). A fixação foi realizada perpendicularmente em uma resina 13 × 34 mm para implantes curtos e uma resina 19 × 34 mm para implantes padrão, usando um topógrafo. Os pilares da mesma altura, mas com diferentes comprimentos de manguito (2,5 mm para os implantes padrão e 5,5 mm para os implantes curtos) foram apertados com 30 N, utilizando um torquímetro digital. Para compensar o efeito de sedimentação, o parafuso do pilar foi reapertado com 30 N após 10 min. Depois de aplicar 500.000 ciclos a 75 N e 1 Hz ao longo do eixo longitudinal em cada amostra, o valor de torque reverso cego foi medido com um medidor de torque digital. Os dados foram analisados pelo teste t de Student. Resultados: Todos os grupos tiveram perda de torque, mas não houve diferença estatisticamente significativa entre os grupos caso e controle em termos de afrouxamento do parafuso do pilar (p = 0451). Conclusão: Os implantes curtos parecem ser uma boa alternativa mecânica em emergências em termos de perda de torque e afrouxamento do parafuso do pilar. (AU)
Subject(s)
Bone Screws , Torque , Dental ImplantationABSTRACT
ABSTRACT Objective: To evaluate the effects of passive self-ligating appliances (PSLAs) and conventional ligating appliances (CLAs) during orthodontic treatment regarding torque, tip, and transversal dental changes. Material and Methods: Dental parameters were digitally acquired from pre- and post-treatment models of each subject belonging to two groups of patients treated with PSLAs (23 patients; 11 females and 12 males with a mean age of 14.2 ± 1.6 years) and CLAs (18 patients; 10 females and 8 males with a mean age of 14.3 ± 1.9 years), respectively. All subjects had Class I or slight Class II malocclusion (= 2mm), permanent dentition and no previous orthodontic treatment. After normality of data was assumed, a paired sample t-test rejected any side differences at T0 and, therefore, the data were grouped by tooth group. Statistical analyses were performed using a linear mixed-effect framework, assuming the appliance, time, and interactions as fixed effects and the tooth type as random effects. Finally, post-hoc effect analysis was used to contrast modeled marginal effects (p<0.05). Results: For both appliances, there is a general increase of both torque and transverse values at T1, especially for PSLAs. Tip shows a general reduction in the lateral sectors for both appliances is registered. The only significant statistical difference referred to appliances' efficacy is located to mandibular intermolar width. Conclusion: Both appliances have an expansive potential for both torque and transverse dental changes. No evident differences are detectable between appliances except for the rate of the mandibular intermolar width increase.
Subject(s)
Humans , Male , Female , Child , Adolescent , Orthodontic Appliances , Orthodontic Brackets , Torsion, Mechanical , Malocclusion/etiology , Malocclusion, Angle Class I/etiology , Retrospective Studies , Data Interpretation, Statistical , Torque , ItalyABSTRACT
O objetivo do presente estudo foi investigar a ação da associação de medicação sistêmica (bifosfonato oral) e teriparatida como medicação local funcionalizando as superfícies dos implantes. Para a realização deste projeto, o mesmo foi divido em 2 etapas. A primeira etapa consistiu na determinação do melhor protocolo para a funcionalização de implantes com teriparatida, a partir da técnica layer by layer. Ainda nesta etapa, foram realizados testes físicos e in vitro (culturas de células) a fim de avaliar as propriedades da superfície funcionalizada, quanto à melhora nas respostas osteogênicas. A segunda etapa consistiu na realização de experimentos in vivo para avaliar o efeito desta superfície funcionalizada durante o reparo periimplantar. Para isso, 96 ratas Wistar, adultas jovens foram divididas em seis grandes grupos: 1. Grupo SHAM (n=16), no qual os animais foram submetidos à ovariectomia fictícia e dieta balanceada. 2. Grupo SHAM/SM (n=16), no qual os animais receberam dieta de cafeteria. 3. Grupo OVX (n=16), no qual os animais foram submetidos a cirurgia de ovariectomia e não receberam tratamento medicamentoso. 4. Grupo OVX/SM (n=16), no qual os animais foram submetidos à cirurgia ovariectomia e receberam dieta de cafeteria. 5. Grupo OVX/RIS (n=16), no qual os animais foram submetidos à cirurgia de ovariectomia e tratados com risedronato de sódio. 6. Grupo OVX/SM/RIS (n=16), no qual os animais foram submetidos à cirurgia de ovariectomia e à dieta de cafeteria associada ao tratamento medicamentoso com risedronato de sódio. Em cada grande grupo há dois subgrupos: A- implantes convencionais e B- implantes funcionalizados com teriparatida. No dia 0 foi realizada a ovariectomia ou cirurgia fictícia. Passados 30 dias foi iniciado o tratamento medicamentoso com risedronato de sódio. Após 30 dias do início do tratamento medicamentoso, os animais foram submetidos à exodontia do primeiro molar superior direito, em seguida receberam os implantes na região onde foi realizada a exodontia. Aos 28 dias após a instalação dos implantes, os animais foram submetidos à eutanásia para mensuração do torque de remoção. Os dados foram submetidos ao teste de homocedasticidade (Shapiro Wilk). Houve a confirmação de distribuição normal dos dados amostrais e na sequência, foi realizado o teste paramétrico ANOVA One Way, seguido do pós teste de Tukey, com o nível de significância de 5% (p< 0,05). Os implantes funcionalizados apresentaram os maiores valores de torque de remoção em todos os grupos experimentais. A associação sistêmica entre o risedronato de sódio e teriparatida de forma tópica fez com que o grupo OVX/SM/RIS teriparatida obtivesse o maior torque de remoção quando comparado aos demais grupos. Com isso, conclui-se que o desempenho clínico dos implantes funcionalizados com teriparatida foi favorável, no entanto, quando associado à administração sistêmica de risedronato de sódio, os resultados se tornam mais promissores(AU)
The objective of this study was to investigate the action of the association of systemic medication (oral biphosphonate) and teriparatide as local medication functionalized to the surfaces of implants. For the execution of this project, it was divided in 2 stages. The first stage consisted in determining the best protocol for the functionalization of implants with teriparatide, based on the layer by layer technique. Still in this stage, physical and in vitro tests (cell cultures) were performed in order to evaluate the properties of the functionalized surface, regarding the improvement in osteogenic responses. The second stage consisted in conducting in vivo experiments to evaluate the effect of this surface functionalized during the peri-implant repair. For this, 96 Wistar rats, young adults were divided into six large groups: 1. SHAM Group (n=16), where the animals underwent sham surgery and balanced diet. 2. SHAM/SM Group (n=16), in which the animals received a cafeteria diet. 3) Group OVX (n=16), in which the animals underwent ovariectomy without drug treatment. 4. Group OVX/SM (n=16), in which the animals underwent ovariectomy and received a cafeteria diet. 5. Group OVX/SM/RIS (n=16), in which the animals underwent ovariectomy surgery and cafeteria diet associated with drug treatment with sodium risedronate. 6. Group OVX/RIS (n=16), in which the animals underwent ovariectomy and were treated with sodium risedronate. In each large group there are two subgroups: A- conventional implants and B- implants functionalized with teriparatide. After 30 days of beginning the drug treatment, the animals were submitted to bilateral first molar exodontia, then received the implants in the region where the exodontia was performed. At 28 days after installation of the implants, the animals were euthanized to measure the removal torque. The data were submitted to the homoscedasticity test (Shapiro Wilk). There was confirmation of normal distribution of the sample data and in the sequence, the parametric test ANOVA One Way was performed, followed by Tukey's post-test, with the significance level of 5% (p< 0.05). The functionalized implants had the highest removal torque values in all experimental groups. The systemic association between sodium risedronate and teriparatide topically resulted in the OVX/SM/RIS teriparatide group obtaining the highest removal torque when compared to the other groups. Thus, it is concluded that the clinical performance of implants functionalized with teriparatida was favorable, however, when associated with systemic administration of sodium risedronate, the results become more promising(AU)
Subject(s)
Animals , Rats , Osteoporosis , Dental Implants , Teriparatide , Bone Regeneration , TorqueABSTRACT
ABSTRACT Objective: To obtain reference values for tip, torque and in-out from digital models of Italian and Mozambican subjects in ideal occlusion using a repeatable and validated method and to compare these measurements with previously reported values. Material and Methods: Dental parameters were acquired from digital models of each subject, categorized to one of two groups: Italians (23 males, 27 females; mean age 28.3 years, ±5.7 years) and Mozambicans (14 males, 15 females; mean age, 23.4 years, ±5.9), using VAM software. All subjects had ideal occlusion, permanent dentition and no previous orthodontic treatment, fillings or prostheses. After normality of data was assumed (p<0.05), a paired t-test was performed to detect any statistical differences between the two groups (p<0.05). Then, classical inference (t-test and power analysis) was used to compare our data to those reported by other authors. Results: Mozambicans' incisors were more proclined, while their upper molars appeared to be more prominent regarding Italians'. Italians shown greater tip values, especially at the upper first premolars and lower first molars. In-out values were comparable between the two groups, except for the upper molars (more prominent in Mozambicans) and lower first molar (more prominent in Italians). Unlike other reports, upper second molars displayed negative tip in our samples. Conclusion: Pre-adjusted appliances with standard prescription should not be expected to guarantee optimal outcomes. Prescriptions specific for ethnicities are recommended and reference values should be reconsidered.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Orthodontic Appliances , Dentition, Permanent , Torque , Dental Occlusion , Italy , Mozambique , Orthodontics , Statistics, NonparametricABSTRACT
OBJECTIVES: To evaluate the clinical characteristics, ground reaction force (GRF), and function of the plantar muscles and dorsiflexors of the ankle in runners with and without Achilles tendinopathy (AT) and in non-runners. METHODS: Seventy-two participants (42 men, 30 women; mean age: 37.3±9.9 years) were enrolled in this cross-sectional study and divided into three groups: AT group (ATG, n=24), healthy runners' group (HRG, n=24), and non-runners' group (NRG, n=24). Both ankles were evaluated in each group. The American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale was used for clinical and functional evaluation. GRF was evaluated using force plates and muscle strength was evaluated using an isokinetic dynamometer. RESULTS: The AOFAS scores were lower in the ATG. The strike impulse was higher in the ATG than in the HRG and NRG. However, GRF was similar among the groups. The ATG exhibited lower total work at 120°/s speed than the HRG. The peak torque in concentric dorsiflexion was lower in the NRG than in the ATG and HRG. The peak torque and total work in concentric plantar flexion were lower in the NRG than in the ATG. The peak torque and total work in eccentric plantar flexion were lower in the NRG than in the ATG and HRG. CONCLUSION: Runners with AT showed higher strike impulse, lower muscle strength of the plantar flexors, and higher clinical and functional damage.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Achilles Tendon , Tendinopathy , Biomechanical Phenomena , Cross-Sectional Studies , Muscle, Skeletal , Torque , Muscle Strength , Ankle , Ankle JointABSTRACT
This study designed an isokinetic muscle strength rehabilitation training equipment, based on oil resistance. The equipment detected joint angles during movement through displacement sensors to measure the angular velocity in real-time. Then it can achieve flow resistance adjustment and constant velocity movement, based on the flow area of the proportional valve calculated by PID algorithm and the deviation between the set speed and the measured speed. The equipment can also collect muscle strength during exercise through force-sensitive sensors to achieve real-time and accurate assessment of muscle strength. Moreover, the study preliminarily certificated the isokinetic motion the results showed that the mean error of peak torque test is less than 5%, and the correlation is between 0.89 and 0.92 (
Subject(s)
Humans , Exercise Therapy , Movement , Muscle Strength , Muscle, Skeletal , TorqueABSTRACT
Introdução: o aprimoramento do processo de osseointegração faz com que os investimentos em pesquisa e o desenvolvimento de novos materiais e tratamentos de superfície sejam despendidos para promover a relação entre osso e implante. Uma das condições para o sucesso é a ausência de micromovimentos ou estabilidade primária da peça implantada, fato esse que leva alguns cirurgiões a aplicar torques excessivos sobre o implante, podendo resultar em danos ao tratamento aplicado à superfície externa do mesmo. Objetivo: o presente trabalho investigou possíveis níveis de deformação do preparo de superfície conforme diferentes valores de torque foram aplicados à dois sistemas de implantes para avaliar os possíveis danos causados. Metodologia: foram instalados 5 implantes do sistema Dérig e 5 implantes do sistema Straumann em um bloco de poliuretano, para posterior remoção com contra-torque e avaliação da superfície sob o Microscópio Eletrônico de Varredura (MEV). Resultados: nos resultados obtidos, no grupo de implantes Dérig não foi possível constatar evidências que comprovem que a elevação dos valores de torque aplicados aos implantes até 95 Ncm danifiquem ou alterem a estrutura do preparo de superfície externa dos implantes, contudo, no grupo Straumann, verificamos danos e alterações no preparo de superfície com torque progressivo a partir de 50 Ncm. Conclusão: possíveis alterações e danos ao preparo de superfície de implantes que apresentem rugosidade de superfície aumentada por jateamento podem ocorrer em torques acima de 50 Ncm empregados com o objetivo de aumentar sua estabilidade primária.
Introduction: improving the osseointegration process means that investments in research and development of new materials and surface treatments are expended to promote the relationship between bone and implant. One of the conditions for success is the absence of micromovements or primary stability of the implanted part. This fact causes some surgeons to apply excessive torque to the implant, which may result in damage to the treatment applied to the external surface of the implant. Objective: The present work investigated possible surface preparation deformation levels as different torque values were applied to two implant systems to evaluate the possible damage caused. Methodology: ive Dérig system implants and five Straumann system implants were installed in a polyurethane block for subsequent counter-torque removal and surface evaluation under the Scanning Electron Microscope (SEM). Results: Iin the obtained results, in the Dérig implant group it was not possible to verify evidences that the increase of the torque values applied to the implants up to 95 Ncm could damage or alter the structure of the external surface preparation of the implants, however, in the Straumann group we verified damage and changes in surface preparation with progressive torque from 50 Ncm. Conclusion: possible alterations and damages to the surface preparation of implants that present increased surface roughness by blasting can occur in torques above 50 Ncm employed in order to increase their primary stability.
Subject(s)
Torque , Dental Implantation , Tooth Wear , Polyurethanes , Bone and BonesABSTRACT
La incorporación de los microimplantes a la ortodoncia revoluciona la mecánica de cierre de espacios por deslizamiento, ya que mejora sus dos puntos "débiles": el anclaje y el control dentario tridimensional. El propósito de este trabajo es determinar los vectores de fuerza y el tipo de movimiento generado en la retrusión en masa del sector anterosuperior, según las distintas ubicaciones de los microtornillos y la altura del brazo de la palanca anterior. Las nuevas tendencias de utilización de microimplantes para la retrusión producen vectores de fuerza horizontales y verticales y momentos según su ubicación y según el punto de aplicación de la fuerza. Debido a esto último, el conocimiento de la biomecánica adquiere especial importancia para un correcto resultado final en el tratamiento ortodóncico. Un diagnóstico certero, un objetivo de tratamiento claro y realista y la elección de la aparatología correcta se verán frustrados una y otra vez de no contar con un correcto conocimiento de las reacciones biológicas ante las fuerzas ejercidas (AU)
The incorporation of miniscrew into orthodontics revolutionizes the mechanics of sliding closure spaces, since it improves its two "weak" points: anchoring and three-dimensional dental control. The purpose of this work is to determine the force vectors and the type of movement generated in the mass retrusion of the anterior superior sector according to the different miniscrew´s locations and the anterior lever arm´s height. The new trends in the use of miniscrews for retrusion produce horizontal and vertical force vectors and moments according to their location and the point of application. In consequence, the knowledge of biomechanics acquires special importance to get a correct final result in orthodontic treatment. Not having a detailed knowledge of the biological reactions on the forces exerted will cause that the accurate diagnosis, the clear and realistic treatment objective, and the choice of the correct appliances to be frustrated over and over (AU)