Adaptación marginal e interna de cofias fabricadas por métodos convencionales, CAD/CAM de fresado y sinterizado por láser / Marginal and internal adaptation of copings manufactured by conventional methods, CAD/CAM milling and laser sintering

Introducción: la adaptación marginal e interna de nuestras restauraciones fabricadas por fundición sistemas de fresado y sinterización láser es uno de los factores clínicos más importantes para el éxito de las prótesis fijas, previniendo el riesgo de microfiltración y enfermedad periodontal. Objetivo: evaluar la adaptación marginal e interna de cofias metálicas en aleación Cr-Co confeccionadas por técnicas convencionales, CAD/ CAM de fresado y sinterizado por láser. Material y métodos: estudio de tipo experimental, comparativo e in vitro. Se imprimió un modelo maestro en Cr-Co, proveniente del escaneo de un premolar preparado para corona completa, sobre el cual se diseñaron 30 cofias divididas en tres grupos: el primero que corresponde al grupo cofias fundidas fresadas en disco de cera A (A = 10), el segundo grupo cofias fresadas en disco de metal presinterizado B (B = 10) y el tercer grupo cofias impresas por sinterización láser C (C = 10). Se empleó la réplica de silicona, colocando silicona al interior de cada cofia, sobre el modelo maestro, simulando al cemento, mediante una máquina de ensayo universal se realizó una compresión de 50 N. Luego de retirar cada cofia se rellenaron con silicona pesada de adición, obteniendo una réplica de silicona. Se efectuaron dos cortes transversales en sentido vestíbulolingual y mesiodistal. Se observó el espesor de silicona VPS (vinil poliéter silicona) mediante un estereomicroscopio (Nikon SMZ745T), obteniendo valores en micrómetros. Para el análisis estadístico se utilizó el software SPSS 25 con el fin de realizar la prueba de normalidad y ANOVA de dos vías bajo un nivel de confianza del 95%. Resultados: el menor gap lo obtuvo el grupo de fresadas, seguido de las impresas y por último las fundidas por métodos convencionales. ANOVA de dos vías reveló diferencias estadísticamente significativas entre los tres grupos (p < 0.0001). Conclusiones: se encontró que el gap varía con cada método de fabricación, la técnica convencional de fundido mostró un mayor gap, ninguna excediendo el rango clínicamente aceptable (AU)

Introduction: the marginal and internal adaptation of our restorations manufactured by casting, milling systems and laser sintering is one of the most important clinical factors for the success of fixed prostheses, preventing the risk of microleakage and periodontal disease. Objective: evaluate the marginal and internal adaptation of metal copings in Cr-Co alloy made by conventional techniques, CAD/CAM milling and laser sintering. Material and methods: an experimental, comparative and in vitro study, a Cr-Co master model was printed from the scan of a premolar prepared for a full crown. An experimental, comparative and in vitro study, a Cr-Co master model was printed from the scan of a premolar prepared for a full crown, on which 30 caps divided into three groups were designed; the first group corresponds to the cast copings milled on a wax disc A (A = 10), the second group milled copings on a presintered metal disc B (B = 10) and the third group printed by laser sintering copings C (C = 10). The silicone replica was used, placing silicone inside each coping, on the master model, simulating cement, using a universal testing machine, a 50 N compression was performed. After removing each coping, they were filled with heavy addition silicone, obtaining a silicone replica. Two cross-sections were made in the buccolingual and mesiodistal direction., observing the thickness of the VPS (vinyl polyeter silicone) silicone using a stereomicroscope (Nikon SMZ745T), obtaining values in micrometers. For the statistical analysis, the SPSS 25 software was used in order to perform the normality and two-way ANOVA tests under a 95% confidence level. Results: the smallest gap was obtained by the milled group, followed by the printed ones and finally those cast by conventional methods. Two-way ANOVA revealed statistically significant differences between the three groups (p < 0.0001). Conclusions: the gap was found to vary with each fabrication method, the conventional casting technique showed a larger gap, none exceeding the clinically acceptable range (AU)

Study of laser fluorescence spectroscopy in livers of rats with hypothermic ischemia

Purpose: After partial hepatectomy (PH), the remaining liver (RL) undergoes regenerative response proportional to the host. Limited literature exists on hepatic viability after tissue injury during hypothermic preservation. Spectroscopy measures cellular fluorescence and is explored for tissue characterization and parameter investigation. This study aimed to assess fluorescence analysis (spectroscopy) in evaluating liver viability and its relationship with hepatic tissue regeneration 24 hours after PH. Additionally, we analyzed liver regeneration in RL after 70% partial hepatectomy under hypothermic conditions with laser irradiation. Methods: Fifty-six Wistar rats were divided into four groups: total non-perfused liver (control), total perfused liver, partial hepatectomy "in situ", and partial hepatectomy "ex situ". Tissue analysis was performed at 0 and 24 hours using spectroscopy with laser devices emitting at 532 (green) and 405 nm (violet). Results: Spectroscopy identified tissue viability based on consistent results with Ki67 staining. The fluorescence spectra and Ki67 analysis displayed similar patterns, linking proliferative activity and absorption intensity. Conclusions: Fluorescence spectroscopy proves to be promising for real-time analysis of cellular activity and viability. Metabolic activity was observed in groups of live animals and hypothermically preserved samples, indicating cellular function even under blood deprivation and hypothermic conditions.

The efficiency of ErCr: YSGG laser on the debonding of different thicknesses of ceramic veneers

Aims: To verify the efficacy of Er,Cr:YSGG laser for debonding of lithium disilicate (LD) reinforced glass ceramic veneers of different thicknesses. Methods: Forty bovine teeth were prepared and randomly divided into four groups (n=10/group) according to the ceramic disc thickness: C0.5 (Control group) and L0.5 (Laser irradiated group) in which LD discs had a thickness of 0.5mm and 5mm diameter; C1 and L1 in which LD discs had a thickness of 1mm and 5mm diameter. The lithium disilcate discs (IPS E.max®, shade HTA2) were fabricated following the manufacturer's recommendations and cemented to the prepared tooth surface. The Er,Cr:YSGG laser was applied to the laser groups at 2.5W and 25Hz for 60seconds. Universal testing machine was used to evaluate the shear bond strength for all samples at a cross head speed of 1mm/min in an inciso-gingival direction parallel to the sample surface. After debonding, the samples were examined under stereoscope to evaluate the mode of failure according to the adhesive remnant index (ARI). Results: Laser irradiation significantly diminishes the shear bond strength from 10.868 MPa to 3.778 MPa for C0.5 and L0.5 groups respectively (p=0.00) and from 14.711 MPa to 4.992 MPa for C1 and L1 groups respectively (p=0.00). The shear bond strength required for debonding increased with increasing thickness of discs, but without significant difference (p=0.110). Higher ARI scores were seen in the laser groups (more cement remaining adhered to the tooth) when compared to the control groups. Conclusions: The Er,Cr:YSGG laser could be an effective and useful tool in debonding of lithium disilicate ceramic veneers as it decreases the shear bond strength required for veneer debonding

Thermal expansion and corrosion resistance of cobalt-chromium alloys fabricated by contemporary manufacturing processes: an in vitro study / Expansión térmica y resistencia a la corrosión de aleaciones de cobalto-cromo fabricadas mediante procesos de abricación contemporáneos: un estudio in vitro

In Purpose: The fabrication technique can influence the mechanical properties of Cobalt-Chromium (Co-Cr) dental alloys. Hence, the present study aims to determine the corrosion resistance and thermal expansion of alloys manufactured using three contemporary techniques. Material and Methods: A total of nine specimens of Co-Cr alloy were prepared according to ISO 22674 by each one of the three manufacturing processes (three in each process); conventional casting, direct metal laser sintering (DMLS) and milling (MIL). All these specimens were tested for coefficient of thermal expansion and corrosion resistance. The data was tabulated and analyzed statistically. Results: The difference in the thermal expansion of alloys fabricated using three techniques was non-significant at almost all the temperatures from 50 ºC to 950 ºC (p>0.05), except 450 ºC and 600 °C. The polarization resistance of specimens manufactured using the conventional method was more compared to DMLS and MIL at pH 5 (Conventional>MIL>DMLS) (p<0.001). Conclusion: The thermal expansion behavior of alloys manufactured using the three selected techniques were similar, whereas, at acidic pH, the corrosion resistance of conventional and MIL were better than the DMLS.

Antecedentes: La técnica de fabricación puede influir en las propiedades mecánicas de las aleaciones dentales de cobalto-cromo (Co-Cr). Por lo tanto, el presente estudio tiene como objetivo determinar la resistencia a la corrosión y la expansión térmica de aleaciones fabricadas con tres técnicas contemporáneas. Material y Métodos: Se prepararon un total de nueve probetas de aleación de Co-Cr según ISO 22674 por cada uno de los tres procesos de fabricación (tres en cada proceso); fundición convencional, sinterización directa de metal por láser (DMLS) y fresado (MIL). Todos estos especímenes fueron probados para determinar el coeficiente de expansión térmica y la resistencia a la corrosión. Los datos fueron tabulados y analizados estadísticamente. Resultados: La diferencia en la dilatación térmica de las aleaciones fabricadas con las tres técnicas no fue significativa en casi todas las temperaturas desde 50ºC hasta 950ºC (p>0,05), excepto 450ºC y 600ºC. La resistencia a la polarización de las muestras fabricadas con el método convencional fue mayor en comparación con DMLS y MIL a pH 5 (Convencional>MIL>DMLS) (p<0, 0 01). Conclusión: El comportamiento de expansión térmica de las aleaciones fabricadas con las tres técnicas seleccionadas fue similar, mientras que, a pH ácido, la resistencia a la corrosión de la convencional y la MIL fue mejor que la de la DMLS.

#Clareamentoalaser: características das postagens em português no Instagram® / #Clareamentoalaser: characteristics of posts in Portuguese on Instagram®

Objetivo: O objetivo deste estudo foi descrever e avaliar o conteúdo das publicações realizadas usando a hashtag #clareamentoalaser na rede social Instagram®. Materiais e métodos: Foram avaliadas 622 postagens relacionadas ao procedimento de clareamento dentário com uso de luz/laser, publicadas no primeiro trimestre do ano de 2021 (janeiro a março). As características analisadas foram o tipo de perfil, gênero, opinião exposta no conteúdo da publicação, tipo de conteúdo exposto na publicação, nomenclatura do perfil e número de curtidas. A análise foi realizada através do teste qui-quadrado de Pearson, sendo estipulado um nível de significância considerando p-valor <0,05. Resultados:Dentre as 497 publicações incluídas, 77,26% mostraram-se favoráveis ao uso de luz/laser no clareamento. Os valores apurados na variável número de curtidas variam de 0 a 3.361, com média de 42,56 por publicação. Em relação ao tipo de perfil, 60,16% eram cirurgiões-dentistas e 37,83% empresas ou clínicas odontológicas, sendo o conteúdo da publicação majoritariamente comercial (75,65%). Ainda, 53,12% dos perfis foram identificados como do gênero feminino, 9,05% do gênero masculino e 37,83% outros, como empresas ou clínicas odontológicas. Mais de 70% das publicações feitas por profissionais, perfis leigos e empresas ou clínicas odontológicas foram favoráveis ao uso da luz/laser no clareamento dental (p< 0,0001). Discussão: Este estudo expressa a necessidade de educação em saúde, educação continuada e da prática odontológica ba-seada em evidências. Conclusão: Na rede social do Instagram®, houve predominância na divulgação de publicações favoráveis quanto a utilização da luz/laser no clareamento dentário, considerando o período do primeiro trimestre de 2021.

Aim: The aim of this study was to describe and assess the content of publications made using the hashtag #claramentoalaser on the social network Instagram®. Materials and methods: A total of 622 posts related to the tooth whitening procedure with the use of light/laser, published in the first quarter of 2021 (January to March) were evaluated. The characteristics analyzed were the type of profile, gender, opinion exposed in the content of the publication, content exposed in the publication, profile nomenclature and number of likes. The analysis was performed using Pearson's chi-square test, with a significance level considering p-value <0.05. Results: Among the 497 publications included, 77.26% had a positive opinion about the use of light/laser for dental bleaching. The values found in the variable number of likes range from 0 to 3,361, with an average of 42.56 per publication. Regarding the type of profile, 60.16% were dentists, 37.83% com-panies or dental clinics, with commercial content exposed in most publications (75.65%). Still, 53.12% of the profiles were identified as female, 9.05% male and 37.83% others, such as companies or dental clinics. More than 70% of publications made by dentists, lay profiles, and companies or dental clinics had a positive opinion about light/laser use in bleaching (p<0.0001). Discussion: This study expresses the need to adopt an evidence-based practice, health education and continuing education in dentistry. Conclusions: In the Instagram® social network, was identified predominance of publications with a positive opinion about the use of light/laser in tooth whitening in 2021, first quarter.

Elaboração e implantação de protocolo de infiltração e extravasamento de antineoplásicos em acesso venoso central / Elaboración e implementación de un protocolo para la infiltración y extravación de antineoplásicos en el acceso venoso central / Elaboration and implementation of a protocol for infiltration and extravassion of antineoplastics in central venous access

Objetivo: Relatar a experiência na elaboração e implantação do protocolo de extravasamento e infiltração de antineoplásicos em acesso venoso central. Método: estudo descritivo, tipo relato de experiência realizado de fevereiro a maio de 2021. Resultados: Após a busca de evidências na literatura, foi elaborado um fluxograma referente aos cuidados de enfermagem realizados durante e após o extravasamento/infiltração. Além das medidas iniciais padronizou-se o uso da hialuronidase tópica e da fotobiomodulação (1 a 3 joules, com potência de 100 miliwats). A área deveria ser demarcada e se possível fotografada. Após a validação do protocolo por um grupo de enfermeiros especialistas e pelo escritório de qualidade, foi implantado em um Ambulatório de Oncologia de Hospital Público do interior do Estado de São Paulo. Conclusão: Apesar de raro, o extravasamento em acesso central pode acontecer e a equipe precisa de um protocolo assistencial para padronizar a conduta e garantir o sucesso da terapêutica.(AU)

Objective: To report the experience in the elaboration and implementation of the protocol for extravasation and infiltration of anticancer drugs in central venous access. Method: descriptive study, experience report type carried out from February to May 2021. Results: After searching for evidence in the literature, a flowchart was created referring to the nursing care performed during and after the extravasation/infiltration. In addition to the initial measurements, the use of topical hyaluronidase and photobiomodulation (1 to 3 joules, with a potency of 100 milliwatts) was standardized. The area should be demarcated and, if possible, photographed. After validation of the protocol by a group of specialist nurses and by the quality office, it was implemented in an Oncology Outpatient Clinic of a Public Hospital in the interior of the State of São Paulo. Conclusion: Although rare, extravasation in central access can happen and the team needs a care protocol to standardize the conduct and ensure the success of the therapy.(AU)

Objetivo: Informar la experiencia en la elaboración e implementación del protocolo de extravasación e infiltración de fármacos antineoplásicos en acceso venoso central. Método: estudio descriptivo, tipo relato de experiencia realizado de febrero a mayo de 2021. Resultados: Después de la búsqueda de evidencias en la literatura, se elaboró un diagrama de flujo sobre los cuidados de enfermería realizados durante y después de la extravasación/infiltración. Además de las mediciones iniciales, se estandarizó el uso de hialuronidasa tópica y fotobiomodulación (1 a 3 julios, con una potencia de 100 milivatios). El área debe ser delimitada y, si es posible, fotografiada. Después de la validación del protocolo por un grupo de enfermeros especialistas y por la oficina de calidad, fue implantado en un Ambulatorio de Oncología de un Hospital Público del interior del Estado de São Paulo. Conclusión: aunque rara, la extravasación en el acceso central puede ocurrir y el equipo necesita un protocolo de atención para estandarizar la conducta y garantizar el éxito de la terapia.(AU)

Tongue-tie in babies: diagnosis and laser frenectomy: case report / Anquiloglosia en bebés: diagnóstico y frenotomía con láser: informe de caso

Introduction: The World Health Organization (WHO) establishes that breast-feeding must be promoted, supported, and protected due to its benefits in maternal and child health and for the economic, environmental, family and community benefits it produces. Case Report: Ankyloglossia in the newborn can cause early cessation of breastfeeding. A clinical case of a 2-month-old baby, referred to the surgical team of the Dental Service of the Pereira Rossell Hospital Center, with difficulties in breastfeeding due to ankyloglossia is presented. Diagnosis and laser surgical treatment was performed. In the immediate postoperative period, there was an improvement, achieving breastfeeding without the aid of devices, and a progressive improvement during the month following the intervention occurred. Conclusion: Early diagnosis and timely intervention collaborate in the maintenance of lactation and in the progressive improvement of the process.

Introducción: La Organización Mundial de la Salud (OMS) establece que la lactancia materna debe ser promovida, apoyada y protegida por sus beneficios demostrados en la salud materno-infantil y por las ventajas económicas, ambientales, familiares y comunitarias que produce.Reporte de Caso: La anquiloglosia en el recién nacido puede provocar el abandono temprano de la lactancia. Se presenta un caso clínico de un bebe de 2 meses, derivado al equipo quirúrgico del Servicio Odontológico del Centro Hospitalario Pereira Rossell, por dificultades en el amamantamiento a causa de anquiloglosia. Se realizó el diagnóstico y tratamiento quirúrgico con láser. En el postoperatorio inmediato se registró una mejoría en el amamantamiento, logrando la lactancia sin intermediario y una mejoría progresiva en la praxis durante el mes siguiente a la intervención.Conclusión: El diagnóstico precoz y la intervención oportuna colaboran en el mantenimiento de la lactancia y en la mejora progresiva de la praxis.

Uso da fotobiomodulação laser no tratamento de úlceras venosas: uma revisão sistemática / Laser photobiomodulation in the treatment of venous ulcers: a systematic review

O objetivo do presente trabalho foi relatar a eficácia da fotobiomodulação laser na abordagem de úlceras venosas de membros inferiores e como se dá o papel da enfermagem nesse contexto. Tratou-se de uma revisão sistemática que utilizou as bases de dados eletrônicas PubMed, BVS, SCIELO e Lilacs, além da busca no repositório de teses e dissertações pelo cruzamento dos descritores livres e provenientes do DeCS através dos operadores booleanos AND e OR: "laserterapia", "fotobiomodulação laser" e "úlceras venosas". Os critérios de inclusão estabelecidos foram estudos prospectivos, teses e dissertações escritas nos idiomas inglês, português e espanhol, e publicações entre o período de 2010-2020. A revisão foi conduzida conforme metodologia PRISMA, utilizou-se os critérios de Jadad para avaliação da qualidade dos manuscritos. Dos 104 artigos encontrados, apenas 8 contemplavam os critérios de inclusão, tendo uma população total de 942 pacientes. Notou-se que a maioria dos estudos mostrou a eficácia do uso da laserterapia, principalmente quando associado ao uso da terapêutica comum, como a terapia compressiva, agentes tópicos e farmacoterapia. A fotobiomodulação laser demonstrou ser eficaz, porém ainda são necessários mais estudos com o objetivo de uniformizar os parâmetros de aplicação dessa modalidade terapêutica.

The objective of this work was to investigate the effectiveness of laser photo-biomodulation in lower limb venous ulcers and the role of nursing in this context. This is a systematic review, using the PubMed, BVS, SCIELO and Lilacs electronic databases in addition to searching the repository of thesis and dissertations by crossing the free descriptors coming from the DeCS through the Boolean operators AND and OR: "laser therapy", "laser photo-biomodulation" and "venous ulcers". The inclusion criteria were prospective studies, theses and dissertations written in English, Portuguese, or Spanish, and publications in the 2010-2020 period. From the 104 articles found, only 8 met the inclusion criteria, with a total population of 942 patients. It could be observed that most studies showed the effectiveness of using laser therapy, especially when associated with the use of common therapy, such as the compressive therapy, topical agents, and pharmacotherapy. The laser photo-biomodulation was also shown as being effective, but further studies are needed to standardize the application parameters for this therapeutic modality.

Nonsurgical management of an extensive periapical lesion combined with photodynamic therapy: a case report / Manejo não cirúrgico de lesão periapical extensa combinada com terapia fotodinâmica: relato de caso

Introduction: the major goal of endodontic treatment (ET) is the complete elimination and/or maximum possible reduction of bacteria and irritants in the root canal system (RCS). However, persistence of bacterial debris refractory to therapy may leading to ET failure, being necessary to realize conventional or surgical retreatment. Objective: this is a case report on the nonsurgical management of an extensive chronic periapical lesion in teeth 12 and 11 in an adult female patient with history of endodontic treatment failure. She presented with painless swelling and a fistula adjacent to tooth 11. Methodology: conventional ET combined with photodynamic therapy (PDT) was recommended, in addition to calcium hydroxide applications. Regular clinical and radiographic follow-up made over a 2-year period revealed progression of bone regeneration, without sign and symptoms, with a satisfactory outcome. Conclusion: this case report shows that the combination of conservative ET with PDT provided satisfactory results with the resolution of the chronic endodontic infection and bone repair of the extensive periapical lesion.

Introdução: o principal objetivo do tratamento endodôntico (TE) é a eliminação completa e/ou máxima redução possível de bactérias e irritantes no sistema de canais radiculares (SCR). Porém, a persistência de detritos bacterianos refratários à terapia pode levar ao insucesso do TE, sendo necessária a realização do retratamento convencional ou cirúrgico. Objetivo: este relato de caso descreve o manejo não cirúrgico de uma extensa lesão periapical crônica nos dentes 12 e 11 em paciente adulta do sexo feminino com histórico de fracasso endodôntico. A mesma queixava-se de inchaço indolor, com presença de fístula adjacente ao dente 11. Metodologia: preconizou-se a realização do TE convencional associado à terapia fotodinâmica (PDT), com três sessões de troca de hidróxido de cálcio, concluindo-se posteriormente o tratamento. Reavaliações clínicas e radiográficas periódicas ao longo de 2 anos revelaram a progressão da consolidação óssea, com um desfecho satisfatório. Conclusão: este relato de caso mostra que a combinação do TE conservador associado à PDT teve resultados satisfatórios na resolução de infecção endodôntica crônica e no reparo ósseo de lesão periapical extensa.

Identificación directa de microorganismos a partir de hemocultivos positivos utilizando espectrometría de masas (MALDI-TOF MS) / Direct identification of microorganisms in positive blood culture bottles by mass spectrometry (MALDI-TOF MS)

Resumen La espectrometría de masas (MALDI-TOF MS) permite la identificación de microorganismos directamente de las colonias en pocos minutos. En este estudio se ha desarrollado y evaluado un protocolo reducido para identificar microorganismos directamente de las botellas de hemocultivos positivos en 30 minutos con una alta sensibilidad y especificidad, utilizando MALDITOF. Un total de 2535 hemocultivos positivos fueron estudiados por el método directo de MALDI-TOF MS, a partir de una alícuota de sangre de las botellas y el método de colonia, utilizando los cultivos desarrollados en medios sólidos. Del total de hemocultivos positivos incluidos en este estudio, 2381 (93,9%) fueron monomicrobianos y 146 (5,8%) polimicrobianos. Mil trescientos treinta (55,9%) de los aislamientos correspondieron a cocos gram positivos, 922 (38,7%) a bacilos gram negativos, 60 (2,5%) a anaerobios, 36 (1,5%) a bacilos gram positivos y 13 a levaduras. La concordancia global entre ambos métodos fue del 81,7% a nivel de especie (90,0% para bacilos gram negativos, 76,7% para cocos gram positivos y 33,3% para bacilos gram positivos). Se identificó al menos un germen en el 88% de las botellas positivas con desarrollo polimicrobiano. Los resultados del presente estudio demostraron que el protocolo basado en MALDI-TOF MS permite la identificación microbiana directamente de hemocultivos positivos en un tiempo corto, con una alta precisión, con excepción de los bacilos gram positivos.

Abstract Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) enables the identification of microorganisms directly from colonies within minutes. In this study this technology was adapted and tested for use with blood culture bottles, thus allowing identification in 30 minutes once the blood culture is detected as positive by the automate. A total of 2535 blood culture bottles reported as positive were tested by MALDI-TOF MS directly from positive blood culture bottles and colonies. A total of 2381 (93.9%) and 146 (5.8%) of the positive blood cultures were monomicrobial and polymicrobial, respectively. And 1330 (55.9%), 922 (38.7%), 60 (2.5%), 36 (1.5%) and 13 of the isolates were gram-positive cocci (GPC), gram-negative bacilli (GNB), anaerobic bacteria, gram-positive bacilli (GPB) and yeast respectively. Concordance between both methods was 81.7% (76.7% of GPC, 90% of GNB, 74.2% of anaerobic bacteria and 33.3% of GPB) in monomicrobial cultures. Eighty eight per cent of the polymicrobial cultures were identified correctly in at least one of the two bacteria. The results of the present study show that this fast, MALDI-TOF MS based method allows microbial identification directly from positive blood culture in a short time, with a high accuracy, with the exception of gram-positive bacilli.

Resumo A espectrometria de massa (MALDI-TOF MS) permite a identificação de microorganismos diretamente das colônias em minutos. Nesse estudo, foi desenvolvido um protocolo reduzido para identificar microrganismos diretamente das garrafas de hemoculturas positivas em 30 minutos com alta sensibilidade e especificidade, utilizando MALDI-TOF. Um total de 2535 hemoculturas positivas foram relatadas -o método direto de MALDI-TOF MS, a partir de uma alíquota de sangue dos vidros e o método de colônia, a partir das culturas desenvolvidas em meios sólidos. Do total de hemoculturas positivas incluídas neste estudo, 2.381 (93,9%) eram monomicrobianas e 146 (5,8%) eram polimicrobianas. Mil trezentos e trinta (55,9%) dos isolados corresponderam a cocos gram-positivos, 922 (38,7%) bacilos gram-negativos, 60 (2,5%) anaeróbios, 36 (1,5%) bacilos gram-positivos e 13 leveduras. A concordância geral entre os dois métodos foi de 81,7% em nivel de especie (90,0% para bacilos gram-negativos, 76,7% para cocos gram-positivos e 33,3% para bacilos gram-positivos). Pelo menos um germe foi identificado em 88% dos vidros positivos com desenvolvimento polimicrobiano. Os resultados do presente estudo demonstraram que o protocolo baseado em MALDI-TOF MS permite a identificação microbiana diretamente de hemoculturas positivas em um curto espaço de tempo, com alta precisão, com exceção de bacilos gram-positivos.

Análisis Forense de Códigos QR Grabados con Láser en Prótesis Dentales Acrílicas / Forensic Analysis of Laser Engraved QR Codes on Acrylic Dental Prostheses

El objetivo del presente estudio fue evaluar la lectura e interpretación de códigos QR grabados con láser, sobre soportes metálicos adaptados, en prótesis den-tales acrílicas sometidas a injurias térmicas y ácidas. Se confeccionaron 150 prótesis de acrílico termopo-limerizable: 120 prótesis fueron expuestas a la acción de temperaturas de 200ºC, 400ºC, 800ºC y 1000ºC durante 30, 60 y 120 minutos (Grupo 1). Este grupo se dividió en un subgrupo 1.A, que incluyó 60 prótesis con el código QR grabado sobre un soporte de cromo cobalto adaptado en el acrílico, y un subgrupo 1.B, con 60 aparatos protésicos que portaban en su estruc-tura un soporte de acero para bandas de ortodoncia con el código QR. Las 30 prótesis remanentes confor-maron el Grupo 2 y se dividieron en subgrupo 2.A (15 prótesis con el soporte de cromo cobalto), y subgrupo 2.B (15 prótesis con el soporte de acero para bandas de ortodoncia), todas sumergidas en ácido clorhídrico al 40 % a temperatura ambiente, durante 30, 60 y 120 minutos. Los análisis estadísticos para comparación entre grupos e inter-grupos fueron ANOVA y prueba de Tukey, todos con nivel de significancia p<0,05. En el Grupo 1, la lectura positiva de los códigos QR fue del 75 % para el subgrupo 1.A, y 12 % en el subgrupo 1.B. Para el Grupo 2, la lectura positiva de los códigos QR resultó en un 66 % en el subgrupo 2.A, y 0 % para el subgrupo 2.B. Se concluyó que pese a los efectos vulnerantes de los agentes físicos y químicos sobre el acrílico, bajo ciertas condiciones es posible leer e interpretar códigos QR grabados con láser sobre so-portes metálicos adaptados en la estructura protéti-ca, representando una alternativa para la identificación humana (AU)

The objective was to evaluate the reading and interpretation of laser-engraved QR codes on metal supports adapted to acrylic dental prostheses subjected to thermal and acid insults. Were made 150 thermo-curing acrylic prostheses, 120 prostheses were exposed to the action of temperatures of 200ºC, 400ºC, 800ºC and 1000ºC for 30, 60 and 120 minutes (Group 1). This group was divided into a subgroup 1.A that included 60 prostheses with the QR code engraved on a cobalt chromium support adapted to the acrylic and a subgroup 1.B with the other half of the prosthetic appliances, which had in their structure a support of steel for orthodontic bands with QR code. The 30 remaining prostheses made up Group 2 and were divided into subgroup 2.A (15 prostheses with cobalt chromium support) and subgroup 2.B (15 prostheses with steel support for orthodontic bands) all submerged in hydrochloric acid 40% at room temperature, for 30, 60 and 120 minutes. The statistical analyzes for groups comparison and between groups were ANOVA and Tukey's test, all with a significance level of p <0.05. In Group 1, the positive reading of the QR codes was 75% for Subgroup 1.A and 12% in subgroup 1.B. For Group 2, the positive reading of the QR codes resulted in 66% in subgroup 2.A and 0% for subgroup 2.B. Conclusion: Despite the damaging effects of physical and chemical agents on acrylic, under certain conditions it is possible to read and interpret laser-engraved QR codes on metal supports adapted to the prosthetic structure, which may represent an alternative for human identification (AU)

Uso da fototerapia como método complementar no retratamento endodôntico: revisões sistemáticas e meta-análise de ensaios clínicos / Use of phototherapy as a complementary method in endodontic reintervention: systematic reviews and meta-analysis of clinical trials

Este trabalho objetivou realizar duas revisões sistemáticas com as seguintes propostas: 1) Avaliar se a fototerapia com laser resultaria em menor dor pós-operatória (PP) em pacientes submetidos a reintervenção endodôntica; e 2) Avaliar se o uso da terapia fotodinâmica antimicrobiana (aPDT) seria eficaz na desinfecção de canais radiculares em casos de reintervenção endodôntica. As Revisões Sistemáticas foram registradas no PROSPERO (CRD42021243500 e CRD42021260013, respectivamente) e seguiram as diretrizes dos Itens de Relatório Preferenciais para Revisões Sistemáticas e Meta-análise (PRISMA). As buscas foram realizadas nas bases de dados eletrônicas PubMeb, Scopus, Web of Science, Embase, Web of Science, Clinical Trials e Cochrane Library e nos bancos de dados da literatura cinza. A qualidade metodológica e o risco de viés foram avaliados pela ferramenta Cochrane Risk of Bias para ensaios clínicos randomizados (RCT) e pelo qualificador NewcastleOttawa (NOS) para estudos não RCT (prospectivos). A análise da qualidade de evidência foi realizada com base na abordagem GRADE. A meta-análise foi realizada com o R software Meta package, utilizando um intervalo de confiança (IC) de 95%. Quanto aos resultados do Artigo 1: Cinco artigos foram incluídos para análise. Os estudos foram classificados como "baixo" risco de viés. Dos cinco estudos clínicos, quatro estudos mostraram uma diminuição significativa da PP após a reintervenção endodôntica nos grupos de fototerapia a laser quando comparados ao grupo controle, principalmente nos primeiros dias após a intervenção. A certeza de evidência foi classificada como baixa. Devido à alta heterogeneidade clínica entre os estudos, não foi possível realizar qualquer meta-análise. Apesar das limitações desta revisão sistemática, a fototerapia se mostrou uma alternativa promissora na redução e controle da PP na reintervenção endodôntica não cirúrgica. Nos resultados do Artigo 2, dez estudos atenderam aos critérios de elegibilidade e foram incluídos, sendo 8 utilizados na síntese quantitativa. A meta-análise mostrou que todos os dados dos estudos apresentaram diferença significativa antes e depois da terapia fotodinâmica antimicrobiana na redução da carga microbiana em infecções endondônticas secundárias (OR 0,15 [0,07; 0,32], p < 0,0001). No geral, os estudos apresentaram baixo risco de viés e a análise das evidências foi classificada como moderada. Sugere-se que a terapia fotodinâmica seja uma ferramenta benéfica e promissora, mostrando eficácia na redução da carga microbiana nos casos de reintervenção endodôntica. Em suma, a abordagem da utilização da fototerapia se demonstrou eficaz na diminuição da dor pós-operatória e na desinfecção dos canais radiculares, podendo ser uma terapia indicada nos casos de reintervenção endodôntica(AU)

This study aimed to carry out two systematic reviews with the following proposals: 1) Evaluate whether laser phototherapy would result in less postoperative pain (PP) in patients undergoing endodontic reintervention; and 2) Evaluate whether the use of antimicrobial photodynamic therapy (aPDT) would be effective in disinfection of root canals in cases of endodontic reintervention. Systematic Reviews were registered in PROSPERO (CRD42021243500 and CRD42021260013, respectively) and followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Metaanalysis (PRISMA). Searches were performed in the electronic databases PubMeb, Scopus, Web of Science, Embase, Web of Science, Clinical Trials and Cochrane Library and in the gray literature databases. Methodological quality and risk of bias were assessed by the Cochrane Risk of Bias tool for randomized clinical trials (RCT) and by the Newcastle-Ottawa (NOS) qualifier for non-RCT (prospective) studies. The analysis of the quality of evidence was performed based on the GRADE approach. The meta-analysis was performed using the R Meta package software, using a 95% confidence interval (CI). As for the results of Article 1: Five articles were included for analysis. Studies were classified as "low" risk of bias. Of the five clinical studies, four studies showed a significant decrease in PP after endodontic reintervention in the laser phototherapy groups when compared to the control group, mainly in the first days after the intervention. The certainty of evidence was rated low. Due to the high clinical heterogeneity between studies, it was not possible to perform any meta-analysis. Despite the limitations of this systematic review, phototherapy proved to be a promising alternative for the reduction and control of PP in conventional endodontic reintervention. In the results of Article 2, ten studies met the eligibility criteria and were included, being 8 used in the quantitative synthesis. The meta-analysis showed that all data from the studies showed a significant difference before and after antimicrobial photodynamic therapy in reducing the microbial load in secondary endodontic infections (OR 0.15 [0.07; 0.32], p < 0.0001). Overall, the studies presented a low risk of bias and the analysis of evidence was rated as moderate. It is suggested that photodynamic therapy is a beneficial and promising tool, showing efficacy in reducing the microbial load in cases of endodontic reintervention. In summary, the approach to the use of phototherapy has been shown to be effective in reducing postoperative pain and disinfection of root canals, and may be an indicated therapy in cases of endodontic reintervention(AU)

Effects of photobiomodulation (660 nm laser) on anthracycline extravasation: An experimental study / Efeitos da fotobiomodulação (laser 660 nm) no extravasamento de antraciclina: estudo experimental / Efectos de la fotobiomodulación (láser de 660 nm) sobre la extravasación de antraciclinas: estudio experimental

Abstract Objective: to investigate the effect of using different agents (topical hyaluronidase, photobiomodulation, and the association of photobiomodulation with topical hyaluronidase) in preventing the formation of lesions caused by doxorubicin extravasation, as well as in the reduction of lesions formed by extravasation of this drug. Method: a quasi-experimental study conducted with 60 Wistar rats, randomized into four groups with 15 animals each. Group 1 (Control); Group 2 (Hyaluronidase); Group 3 (Photobiomodulation); and Group 4 (Hyaluronidase + Photobiomodulation). A wound was induced by applying 1 mg of doxorubicin to the subcutaneous tissue of the back of the animals. The concentration of topical hyaluronidase was 65 turbidity units/g and the energy employed was 1 joule of 100 mW red laser per square centimeter. With macroscopic evaluation every two days for 28 days, the following variables were observed: skin integrity, presence of blisters, hyperemia, exudate, bleeding, edema, crust, peeling and granulation tissue. Results: the animals from the groups subjected to photobiomodulation obtained better results in the assessment of the following variables: bleeding, hyperemia, exudate, intact skin and edema. Conclusion: it was evidenced that the association of photobiomodulation with topical hyaluronidase was effective in reducing the local effects and assisted in the wound healing process, and that PBM alone was able to prevent appearance of lesions.

Resumo Objetivo: investigar o efeito do uso de diferentes agentes (hialuronidase tópica, fotobiomodulação e da associação da fotobiomodulação com a hialuronidase tópica) na prevenção de formação de lesões causadas por extravasamento de doxorrubicina bem como na diminuição de lesões formadas pelo extravasamento desta droga. Método: estudo experimental com 60 ratos Wistar, randomizados em quatro grupos de 15 animais. Grupo 1 (Controle); Grupo 2 (Hialuronidase); Grupo 3 (Fotobiomodulação) e Grupo 4 (Hialuronidase + Fotobiomodulação). Induziu-se ferida aplicando 1 mg de doxorrubicina no subcutâneo do dorso dos animais. A concentração da hialuronidase tópica foi de 65 unidades de turbidez/g, a energia empregada foi de 1 joule de laser vermelho 100 mW por centímetro quadrado. Com avaliação macroscópica a cada dois dias por 28 dias, observou-se as variáveis: integridade da pele, presença de flictema, hiperemia, exsudato, sangramento, edema, crosta, descamação e tecido de granulação. Resultados: os animais dos grupos com fotobiomodulação obtiveram melhores resultados na avaliação das variáveis: sangramento, hiperemia, exsudato, pele íntegra e edema. Conclusão: evidenciou-se que a associação da fotobiomodulação com a hialuronidase tópica foi eficaz na diminuição dos efeitos locais e auxiliou no processo de cicatrização da ferida e que a FBM isolada foi capaz de prevenir o aparecimento de lesões.

Resumen Objetivo: investigar el efecto del uso de diferentes agentes (hialuronidasa tópica, fotobiomodulación y la combinación de fotobiomodulación y hialuronidasa tópica) en la prevención de la formación de lesiones causadas por la extravasación de doxorrubicina y en la reducción de las lesiones formadas por la extravasación de ese fármaco. Método: estudio experimental con 60 ratas Wistar, distribuidos aleatoriamente en cuatro grupos de 15 animales. Grupo 1 (Control); Grupo 2 (Hialuronidasa); Grupo 3 (Fotobiomodulación) y Grupo 4 (Hialuronidasa + Fotobiomodulación). La herida se indujo aplicando 1 mg de doxorrubicina por vía subcutánea en el lomo de los animales. La concentración de hialuronidasa tópica fue de 65 unidades de turbidez/g, la energía utilizada fue de 1 joule de láser rojo de 100 mW por centímetro cuadrado. En la evaluación macroscópica cada dos días durante 28 días se observaron las siguientes variables: piel intacta, presencia de flictena, hiperemia, exudado, sangrado, edema, costra, descamación y tejido de granulación. Resultados: los animales de los grupos con fotobiomodulación obtuvieron mejores resultados en la evaluación de las variables: sangrado, hiperemia, exudado, piel intacta y edema. Conclusión: se demostró que la combinación de fotobiomodulación y hialuronidasa tópica fue eficaz para reducir los efectos locales y ayudó en el proceso de cicatrización de heridas y que la FBM por sí sola previno la aparición de lesiones.

Evaluation of Antimicrobial Photodynamic Therapy as an Adjuvant in Periodontal Treatment in Individual with Down Syndrome

Abstract Objective: To evaluate the effectiveness of Antimicrobial Photodynamic Therapy (aPDT), associated with scaling and root planing in the non-surgical periodontal treatment of individuals with Down Syndrome. Material and Methods: A controlled, randomized, split-mouth study was conducted. A total of 8 participants diagnosed with Down Syndrome aged 17-38 years of both sexes with clinical periodontitis were included in the study. Participants were treated at least three times: at the baseline, Plaque Index (PI), Bleeding on Probing (BOP), and Probing Pocket Depth (PPD) were obtained. After one week, conventional scaling and root planing were performed, and two quadrants were randomly selected for aPDT application. The reassessment was obtained one month after the aPDT application. The significance level was set at 5%. Analyses were performed considering a 95% confidence interval. Results: In the intergroup evaluation, no statistically significant differences were observed (p>0.05). In the intragroup evaluation, no statistically significant variations were observed in relation to the PI (p>0.05) and PPD (p>0.05); however, a statistically significant reduction in the BOP was observed between the test group (p=0.013) and control group (p=0.015). Conclusion: The use of aPDT as adjuvant therapy did not promote additional benefits in decreasing PI and PPD after 1 month of treatment. However, a significant reduction in the BOP was observed in the intragroup evaluation.

Difusão e propaganda sobre antienvelhecimento na mídia brasileira: um estudo de representações sociais / Diffusion and propaganda about anti-aging in brazilian media: a study of social representations / Difusión y propaganda sobre el antienvejecimiento en los medios de comunicación brasileños: un estudio de las representaciones sociales

Esta pesquisa buscou mapear conteúdos relativos ao antienvelhecimento em revistas de grande circulação e no noticiário brasileiro, entre 1º de janeiro de 2016 e 31 de dezembro de 2019. Foram investigadas as revistas Claudia, Boa Forma, VIP e Carbono Uomo. Houve ainda coleta no portal de notícias G1, da Rede Globo de Televisão, voltado ao público geral. Foram criados dois corpora distintos formados pelos conteúdos do G1 e das revistas que, então, foram submetidos à Classificação Hierárquica Descendente pelo software IRaMuTeQ, dando origem a dois subcorpora e quatro classes para cada um. Os resultados apontam uma forte tendência mercadológica nas revistas, que buscam conduzir os leitores ao consumo de produtos e à realização de procedimentos estéticos. Por outro lado, as notícias jornalísticas apregoam um modelo de vida mais saudável como principal prática antienvelhecimento, ao mesmo tempo que alertam sobre os riscos envolvidos nos procedimentos e produtos estéticos irregulares. Em geral, o conteúdo das revistas dissipa representações sociais que idealizam um padrão de beleza do corpo jovial, associando a velhice à fealdade, enquanto o do portal de notícias G1 voltam-se à saúde e longevidade.(AU)

This survey aimed to map anti-aging content, in magazines with wide circulation and also in Brazilian news, between January 1, 2016 and December 31, 2019. Claudia, Boa Forma, VIP and Carbono Uomo magazines were studied. News were also collected from the G1 news portal, from Globo television network, aimed at the general audience. Two distinct corpora formed by the contents of the G1 and the magazines were created, which were then submitted to the Descending Hierarchical Classification, by the IRaMuTeQ software, leading to two subcorpora and four classes for each. The results show a strong market orientation in the magazines, which aim to lead readers to purchase products and undertake aesthetic procedures. The news reports, on the other way, promote a healthier life model as the main anti-aging practice, while warning about the risks involved in irregular aesthetic procedures and products. In general, the content of the magazines spreads social representations which idealize a pattern of beauty of a young body, connecting old age with ugliness, whereas that of the G1 news portal are focused on health and longevity.(AU)

Esta iniciativa buscó mapear material de antienvejecimiento, en revistas de gran tirada y en las noticias de Brasil, entre el 1 de enero de 2016 y el 31 de diciembre de 2019. Se analizaron las revistas Claudia, Boa Forma, VIP y Carbono Uomo. También se recogieron noticias del sitio de noticias G1 y de la red de televisión Globo, ambas dirigidas al público en general. Se crearon dos corpora distintos formados por el contenido del G1 y de las revistas, que luego fueron sometidos a la Clasificación Jerárquica Descendente, por el software IRaMuTeQ, dando lugar a dos subcorpora y cuatro clases para cada uno de los corpora. Los resultados señalan una fuerte orientación del mercado de promoción en las revistas, que buscan llevar a los lectores a consumir productos y realizar procedimientos estéticos. En cambio, las noticias periodísticas difunden un modelo de vida más saludable como la principal práctica antienvejecimiento, mientras que al mismo tiempo advierten sobre los riesgos que implican los procedimientos irregulares y los productos estéticos. De forma general, el contenido de las revistas difunde representaciones sociales que idealizan un estándar de belleza del cuerpo joven, asociando la vejez con la fealdad, mientras que el del portal de noticias G1 se orienta a la salud y la longevidad.(AU)

Láser de baja intensidad en pulpotomía de dientes primarios / Laser de baixa intensidade em pulpotomia de dentes decíduos / Low-level laser in pulpotomy of deciduous teeth

Las altas tasas de lesiones cariosas en niños y adolescentes pueden resultar en la exposición pulpar o incluso en la pérdida temprana del diente primario, situación que requiere una acción mínimamente invasiva por parte del odontólogo, para preservar el diente en la cavidad bucal. La pulpotomía, un tipo de terapia pulpar vital destinada a tratar de forma reversible las lesiones relacionadas con la cámara pulpar, utiliza diferentes técnicas para mantener el diente vital en la cavidad oral hasta la exfoliación. Objetivo: demostrar la efectividad de la técnica de Terapia Láser de Baja Intensidad (LBI) en comparación con el Hidróxido de Calcio en el procedimiento de pulpotomía de dientes primarios. Materiales y Métodos: La investigación fue un ensayo clínico longitudinal con nueve molares primarios de niños de 5 a 12 años. Las evaluaciones clínicas y radiográficas se realizaron después de períodos de 1, 2, 3 y 6 meses. Resultados: Hubo un índice de éxito clínico en cuanto a ausencia de dolor, sensibilidad a la percusión, inflamación y, radiográficamente, ausencia de resorción interna o externa o lesiones de furca en el 100% de los casos. Conclusión: El LBI demuestra beneficios como la ausencia de dolor, el efecto antiinflamatorio y la ausencia de efectos adversos. Por tanto, se sugiere que la LBI puede considerarse una técnica alternativa para la pulpotomía en la práctica clínica. Sin embargo, se recomiendan más estudios clínicos sobre el tema

: Os índices elevados de lesões cariosas em crianças e adolescentes podem resultar em exposição da polpa ou até mesmo na perda precoce do dente decíduo, situação que exige atuação minimamente invasiva do cirurgião-dentista, visando preservar o dente na cavidade bucal. A pulpotomia, um tipo de terapia pulpar vital que visa tratar de forma reversível as injúrias relacionadas à câmara pulpar, utiliza diferentes técnicas com a finalidade de manter o dente vital na cavidade bucal até a sua esfoliação. Objetivo: evidenciar a eficácia da técnica de Laser terapia de Baixa Intensidade (LBI) comparada com o Hidróxido de Cálcio no procedimento de pulpotomia de dentes decíduos. Materiais e método: A pesquisa foi um ensaio clínico longitudinal com nove molares decíduos de crianças com idade entre 5 e 12 anos. Foram realizadas avaliações clínicas e radiográficas após os períodos de 1, 2, 3 e 6 meses. Resultados: Observou-se índice de sucesso clínico quanto à ausência de dor, de sensibilidade à percussão, de inchaço anormal e, radiograficamente, de ausência de reabsorção interna ou de externa ou lesão de furca em 100% dos casos. Conclusão: O LBI demonstra benefícios como a ausência de dor, o efeito anti-inflamatório e a ausência de efeitos adversos. Desta forma, sugere-se que o LBI possa ser considerado uma técnica alternativa para pulpotomia na prática clínica. Porém recomenda-se mais estudos clínicos sobre o assunt

The high rates of carious lesions in children and adolescents can result in pulp exposure or even early loss of the primary tooth, a situation that requires minimally invasive action by the dentist, in order to preserve the tooth in the oral cavity. Pulpotomy, a type of vital pulp therapy aimed at reversibly treating injuries related to the pulp chamber, uses different techniques in order to keep the vital tooth in the oral cavity until exfoliation. Aim: to demonstrate the effectiveness of the Low Intensity Laser Therapy (LBI) technique compared to Calcium Hydroxide in the pulpotomy procedure of primary teeth. Materials and methods: The research was a longitudinal clinical trial with nine primary molars of children aged 5 to 12 years. Clinical and radiographic evaluations were performed after periods of 1, 2, 3 and 6 months. Results: There was an index of clinical success regarding the absence of pain, sensitivity to percussion, abnormal swelling and, radiographically, the absence of internal or external resorption or furcation lesions in 100% of the cases. Conclusion: The LBI demonstrates benefits such as the absence of pain, the anti-inflammatory effect and the absence of adverse effects. Thus, it is suggested that LBI can be considered an alternative technique for pulpotomy in clinical practice. However, further clinical studies on the subject are recommended

Gait Measurement System Using Laser Range Sensor Based on Lower-limb Rehabilitation Robot / 中国医疗器械杂志

Spatiotemporal gait parameters provide important information for the rehabilitation of patients with gait dysfunction. These parameters are often obtained by complex systems such as optical motioncapture system and pressure plates. However, these systems cannot be deployed at the lower-limb rehabilitation robot easily because of high costs, large area occupation and wearable requirements. We present a gait measurement system with a Light Detection And Ranging(LIDAR) laser sensor based on the lower-limb rehabilitation robot. Firstly, to calculate gait parameters, the data are aggregated into left and right legs by the clustering algorithm and the legs contour is fitted with two circles respectively according to the least square method. Then, the spatiotemporal gait parameters are defined based on the time and position of initial contact(IC) and toe off(TO). Finally, to verify the validity of the proposed system, we compared the results of the proposed system with a 3D motion capture system based on a lower-limb rehabilitation robot. Experimental results showed that the gait detection system can measure the parameters within a small range of error that testified the validation of the proposed system. This system proved to be a valid and reliable method for the measurement of gait parameters.

Evaluation on Surgical Robotic Pose Repeatability Based on Laser Tracking Measurement / 中国医疗器械杂志

To provide accurate information for registration and safety evaluation of surgical robot, the pose repeatability measurement method was proposed. According to the terminal instrument of the master-slave surgical robot (such as high-frequency electric knife, ultrasonic knife), a suitable target ball fixture was designed. The node data at 10%, 50% and 100% rated speed were measured respectively. Through data analysis, the pose repeatability property of the tested samples at different speeds was obtained. It has high applicability and repeatability, and can meet the requirements of data traceability and registration testing.

Finite element analyses of retention of removable partial denture circumferential clasps manufactured by selective laser melting / 北京大学学报(医学版)

OBJECTIVE@#To compare the retentions of different designs of cobalt-chromium (Co-Cr), pure titanium (CP Ti), and titanium alloy (Ti-6Al-4V) removable partial denture (RPD) circumferential clasps manufactured by selective laser melting (SLM) and to analyze the stress distribution of these clasps during the removal from abutment teeth.@*METHODS@#Clasps with clasp arm size A (1.9 mm width/1.1 mm thickness at the body and 0.8-taper) or B (1.2 times A) and 0.25 mm or 0.50 mm undercut engagement were modeled on a prepared first premolar die, named as designs A1, A2, A3, and A4, respectively. The density and elastic modulus of SLM-built Co-Cr, CP Ti, and Ti-6Al-4V were measured and given to different groups of clasps. The density, elastic modulus, and Poisson ' s ratio of enamel were given to the die. The control group was the cast Co-Cr clasp with design A1, to which the density and elastic modulus of cast Co-Cr alloy were given. The Poisson's ratio of all metals was 0.33. The initial 5 N dislodging force was applied, and the maximum displacement of the clasp along the insertion path was computed. The load was reapplied with an increment of 5 N than in the last simulation until the clasp was completely dislodged. The retentive force range of different groups of clasps was obtained. The retentive forces of the SLM-built Co-Cr, CP Ti, and Ti-6Al-4V clasps with equivalent computed retentive force range to the control group were validated through the insertion/removal experiment. The von Mises stress distributions of these three groups of SLM-built clasps under 15 N loads were analyzed.@*RESULTS@#SLM-built Co-Cr, CP Ti, and Ti-6Al-4V clasps with designs B1 or B2, and Co-Cr clasps with design A2 had higher retentive forces than those of the control group. SLM-built CP Ti and Ti-6Al-4V clasps with design A1 had lower retentive forces than those of the control group. SLM-built Co-Cr clasp with design A1 and SLM-built CP Ti and Ti-6Al-4V clasps with design A2 had equivalent retentive forces to those of the control group. The insertion/removal experiment showed that the measured retentive forces of these three groups of SLM-built clasps were (21.57±5.41) N, (19.75±4.47) N, and (19.32±2.04) N, respectively. No statistically significant measured retentive force difference was found among these three groups of SLM-built clasps (P>0.05). The maximum von Mises stress of these three groups of SLM-built clasps exceeded their responding yield strength except for the Ti-6Al-4V one.@*CONCLUSION@#SLM-built Co-Cr circumferential clasps had higher retention than CP Ti and Ti-6Al-4V ones with the same clasp arm size and undercut engagement. The retention of SLM-built circumferential clasps could be adjusted by changing the undercut engagement and clasp arm size. If SLM-built circumferential clasps are used in clinical practice, the Ti-6Al-4V clasp with clasp arm size A and 0.50 mm undercut engagement is recommended considering the long-term use of RPD in the patient's mouth.

Influence of laser deproteinization of acid-etched dentin on marginal microleakage of class V composite restoration

Aim: Recent reports indicate that deproteinization of acid-etched dentin surface can extend penetration depth of adhesive agents. The main goal of the present research was to investigate the deproteinization effect of Nd:YAG and diode 940 lasers on acid-etched dentin and microleakage grade in class V composite restorations. Methods: 36 extracted human premolar teeth were selected to make standard buccal and lingual class V cavities. These samples were randomly split into three sub-groups: 1.Control group, in which composite was applied for restoration after etch and bonding process without deproteinization; 2.Nd:YAG laser group, in which the teeth were deproteinized with Nd:YAG laser after etching and painting internal surfaces of cavities with Van Geison stain and then composite restorations applied just as control group; 3.Diode laser group, in which the process was similar to Nd:YAG laser group, but instead, diode 940 laser was irradiated. The teeth were bisected into two equal longitudinal buccal and lingual halves. Marginal microleakage of samples was scored by using a stereomicroscope. Kruskal- Wallis, Mann-Whitney U and Fisher's statistical tests were employed for analysis of the obtained data. Results: A significant reduction in marginal microleakage was observed for both groups treated with laser (Nd:YAG and diode 940)compared to control (p=0.001 & p=0.047). There was no significant difference in marginal microleakage between Nd:YAG laser and diode 940groups (P = 0.333). Conclusion: Nd:YAG and diode 940 laser deproteinization of acid-etched dentin decreased the marginal microleakage of in-vitro class V resin composite restorations