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Objective: The objective of the research was to carry out a comparative study between Smith & Nephew ® or Zimmer ® prostheses with thick versus thin polyethylene, in patients undergoing primary total knee arthroplasty, during a short-term follow-up. Thus, the objective was to analyze the survival of the implants in question under the clinical and radiographic aspect. Methods: The sample was divided into two groups: Group 1 with thick polyethylene and group 2 with thin polyethylene. A clinical analysis of the patients was carried out and the implants were checked for loosening. Results: The groups were similar when compared. According to the Ahlbäck classification, 83% of the patients were in groups IV and V. The median functional score in the postoperative period was similar between the two groups. Postoperatively, the tibiofemoral angle fluctuated between 5 and 6 0 valgus on average. Two complications were observed in each group. None of the evaluated patients presented implant loosening. Conclusion: Patients treated with thick polyethylene had the same functional score as the control group, as well as the absence of radiographic changes in this short-term follow-up, with implant survival and a similar rate of complications between both groups. Level of evidence III, Retrospective study.

Objetivo: O objetivo desta pesquisa foi realizar um estudo comparativo entre as próteses Smith & Nephew ® e Zimmer ®, com polietileno espesso versus o fino, em pacientes submetidos à artroplastia total primária do joelho, durante um seguimento de curto prazo. Dessa forma, foi analisada a sobrevida dos implantes em questão sob o aspecto clínico e radiográfico. Métodos: A amostra foi dividida em dois grupos: grupo 1 com polietileno espesso e grupo 2 com polietileno fino. Foi realizada análise clínica dos pacientes e verificado se ocorreu soltura dos implantes. Resultados: Os grupos tiveram resultados semelhantes quando comparados. Segundo a classificação de Ahlbäck, 83% dos pacientes eram dos grupos IV e V. A mediana do escore funcional no pós-operatório foi similar entre os grupos. No pós-operatório o ângulo tíbio-femoral oscilou na média entre 5 e 6 0 de valgo. Foram observadas duas complicações em cada grupo. Nenhum dos pacientes avaliados apresentou soltura do implante. Conclusão: Os pacientes tratados com o polietileno espesso apresentaram o mesmo escore funcional do grupo controle, assim como ausência de alterações radiográficas nesse seguimento de curto prazo, com sobrevida do implante e índice de complicações similar entre ambos os grupos. Nível de evidência III, Estudo retrospectivo.

RESUMEN

ABSTRACT Objective: The objective of the research was to carry out a comparative study between Smith & Nephew ® or Zimmer ® prostheses with thick versus thin polyethylene, in patients undergoing primary total knee arthroplasty, during a short-term follow-up. Thus, the objective was to analyze the survival of the implants in question under the clinical and radiographic aspect. Methods: The sample was divided into two groups: Group 1 with thick polyethylene and group 2 with thin polyethylene. A clinical analysis of the patients was carried out and the implants were checked for loosening. Results: The groups were similar when compared. According to the Ahlbäck classification, 83% of the patients were in groups IV and V. The median functional score in the postoperative period was similar between the two groups. Postoperatively, the tibiofemoral angle fluctuated between 5 and 6 0 valgus on average. Two complications were observed in each group. None of the evaluated patients presented implant loosening Conclusion: Patients treated with thick polyethylene had the same functional score as the control group, as well as the absence of radiographic changes in this short-term follow-up, with implant survival and a similar rate of complications between both groups. Level of evidence III, Retrospective study.

RESUMO Objetivo: O objetivo desta pesquisa foi realizar um estudo comparativo entre as próteses Smith & Nephew ® e Zimmer ®, com polietileno espesso versus o fino, em pacientes submetidos à artroplastia total primária do joelho, durante um seguimento de curto prazo. Dessa forma, foi analisada a sobrevida dos implantes em questão sob o aspecto clínico e radiográfico. Métodos: A amostra foi dividida em dois grupos: grupo 1 com polietileno espesso e grupo 2 com polietileno fino. Foi realizada análise clínica dos pacientes e verificado se ocorreu soltura dos implantes. Resultados: Os grupos tiveram resultados semelhantes quando comparados. Segundo a classificação de Ahlbäck, 83% dos pacientes eram dos grupos IV e V. A mediana do escore funcional no pós-operatório foi similar entre os grupos. No pós-operatório o ângulo tíbio-femoral oscilou na média entre 5 e 6 0 de valgo. Foram observadas duas complicações em cada grupo. Nenhum dos pacientes avaliados apresentou soltura do implante. Conclusão: Os pacientes tratados com o polietileno espesso apresentaram o mesmo escore funcional do grupo controle, assim como ausência de alterações radiográficas nesse seguimento de curto prazo, com sobrevida do implante e índice de complicações similar entre ambos os grupos. Nível de evidência III, Estudo retrospectivo.

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Background: Mitral valve diseases are a common medical condition, and surgery is the most used therapeutic approach. The need for less invasive interventions led to the development of transcatheter valve implantation in high-risk patients. However, the treatment to the dysfunctions of these prosthetic valves is still uncertain, and the yield and safety of repeated transcatheter valve implantations remain unclear. Cases summary: A 69-year-old Caucasian woman with three previous mitral valve procedures performed due to rheumatic valve disease (currently with a biological prosthetic mitral valve) and a 76-year-old Latin woman with previous liver transplantation (due to metabolic-associated fatty liver disease) and biological mitral prosthesis due to mitral valve prolapse with severe regurgitation underwent mitral valve-in-valve (ViV) transcatheter implantation at the time of dysfunction of their surgical prostheses. Later, these patients developed prosthetic valve dysfunction and clinical worsening, requiring another invasive procedure. Due to maintained high-risk status and unfavourable clinical conditions for surgery, re-valve-in-valve (re-ViV) was performed. Discussion: Valve-in-valve transcatheter mitral valve implantation was approved in 2017, and, since then, it has been used in several countries, mainly in high-risk patients. Nevertheless, these prosthetic valves may complicate with stenosis or regurgitation, demanding reinterventions. Although there are favourable data for mitral ViV, re-ViV still lacks robust data to support its performance, with only case reports in the literature so far. It is possible that in high-risk patients, there is a greater benefit from re-ViV when compared with the surgical strategy. However, this hypothesis must be studied in future controlled trials.

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Abstract Objective: To analyze the association between osteolysis at the prosthesis interfaces, as determined by magnetic resonance imaging (MRI) with multiacquisition variable-resonance image combination selective (MAVRIC-SL) sequences, and clinical severity after knee or hip arthroplasty, as well as to assess interobserver and intraobserver agreement on periprosthetic bone resorption. Materials and Methods: This was a cross-sectional study of 47 patients (49 joints) under postoperative follow-up after knee or hip arthroplasty, with chronic pain, between March 2019 and August 2020. All of the patients completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. The component interfaces were evaluated and ordered into two groups: osseointegrated and osteolytic. Nonparametric tests were used. Results: There were significant differences between the two groups in terms of the mean WOMAC scores: total (p = 0.010); stiffness domain (p = 0.047); and function (p = 0.011) domains. There was substantial interobserver and intraobserver agreement for most analyses of the components. Conclusion: Periprosthetic osteolysis appears to be associated with clinical complaints of pain in the post-arthroplasty scenario, and MAVRIC-SL provides reproducible assessments. It could prove to be an important tool for orthopedists to use in the evaluation of challenging cases of chronic pain after arthroplasty.

Resumo Objetivo: Analisar associação entre osteólise nas interfaces protéticas por ressonância magnética com sequências MAVRIC-SL e a gravidade clínica dos pacientes submetidos a artroplastias de joelho ou quadril. Determinar concordância intraobservador e interobservador na reabsorção óssea peri-implante. Materiais e Métodos: Foi realizado estudo transversal entre março de 2019 e agosto de 2020, com 47 pacientes (49 articulações) em seguimento pós-operatório de artroplastias de joelho ou quadril, com dor crônica, que responderam ao questionário WOMAC. As interfaces dos componentes foram avaliadas e definiram dois grupos: osteointegrado e osteólise. Testes não paramétricos foram usados. Resultados: Houve diferença significativa na média do escore WOMAC entre os grupos (p = 0,010), assim como nos domínios rigidez (p = 0,047) e função (p = 0,011). Houve concordância substancial interobservador e intraobservador para a maioria dos componentes analisados. Conclusão: Osteólise periprótese parece estar associada com a queixa clínica de dor pós-artroplastia, com avaliação reprodutível pela MAVRIC-SL. Isto pode ser uma importante ferramenta para o ortopedista na avaliação de casos desafiadores de dor crônica pós-artroplastia.

RESUMEN

Objective: To analyze the association between osteolysis at the prosthesis interfaces, as determined by magnetic resonance imaging (MRI) with multiacquisition variable-resonance image combination selective (MAVRIC-SL) sequences, and clinical severity after knee or hip arthroplasty, as well as to assess interobserver and intraobserver agreement on periprosthetic bone resorption. Materials and Methods: This was a cross-sectional study of 47 patients (49 joints) under postoperative follow-up after knee or hip arthroplasty, with chronic pain, between March 2019 and August 2020. All of the patients completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. The component interfaces were evaluated and ordered into two groups: osseointegrated and osteolytic. Nonparametric tests were used. Results: There were significant differences between the two groups in terms of the mean WOMAC scores: total (p = 0.010); stiffness domain (p = 0.047); and function (p = 0.011) domains. There was substantial interobserver and intraobserver agreement for most analyses of the components. Conclusion: Periprosthetic osteolysis appears to be associated with clinical complaints of pain in the post-arthroplasty scenario, and MAVRIC-SL provides reproducible assessments. It could prove to be an important tool for orthopedists to use in the evaluation of challenging cases of chronic pain after arthroplasty.

Objetivo: Analisar associação entre osteólise nas interfaces protéticas por ressonância magnética com sequências MAVRIC-SL e a gravidade clínica dos pacientes submetidos a artroplastias de joelho ou quadril. Determinar concordância intraobservador e interobservador na reabsorção óssea peri-implante. Materiais e Métodos: Foi realizado estudo transversal entre março de 2019 e agosto de 2020, com 47 pacientes (49 articulações) em seguimento pós-operatório de artroplastias de joelho ou quadril, com dor crônica, que responderam ao questionário WOMAC. As interfaces dos componentes foram avaliadas e definiram dois grupos: osteointegrado e osteólise. Testes não paramétricos foram usados. Resultados: Houve diferença significativa na média do escore WOMAC entre os grupos (p = 0,010), assim como nos domínios rigidez (p = 0,047) e função (p = 0,011). Houve concordância substancial interobservador e intraobservador para a maioria dos componentes analisados. Conclusão: Osteólise periprótese parece estar associada com a queixa clínica de dor pós-artroplastia, com avaliação reprodutível pela MAVRIC-SL. Isto pode ser uma importante ferramenta para o ortopedista na avaliação de casos desafiadores de dor crônica pós-artroplastia.

RESUMEN

A substituição transcateter valve-in-valve da valva mitral surgiu recentemente como uma alternativa cada vez mais utilizada nos pacientes de alto risco cirúrgico. O presente caso relata uma substituição de valva mitral transcateter valve-in-valve, por via transeptal, como tratamento da degeneração de uma bioprótese mitral cirúrgica e regurgitação grave, em paciente de 86 anos já submetido a uma substituição transcateter valve-in-valve aórtica, há 6 anos. Este caso enfatiza o papel crucial de uma avaliação pré-operatória cuidadosa, com uso de diferentes modalidades de exames de imagem, para planejamento do procedimento, em paciente com maior risco de obstrução da via de saída do ventrículo esquerdo, devido a um procedimento valve-in-valve aórtico prévio.

Transcatheter mitral valve-in-valve replacement has recently emerged as an increasingly common alternative for high surgical risk patients. We report a case of a successful transseptal transcatheter mitral valve-in-valve replacement for the treatment of a bioprosthetic mitral valve degeneration and severe regurgitation, in an 86-year-old patient who had undergone transcatheter aortic valve-in-valve procedure 6 years ago. This case emphasizes the crucial role of a careful preoperative assessment using multimodality imaging to plan the procedure, in a patient with higher risk of left ventricular outflow obstruction due to the previous transcatheter aortic valve-in- valve procedure.

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Abstract The longevity of prosthetic rehabilitation is determined by the stability of the implant and abutment interfaces. True morse taper connections on dental restorations have been effective, however activation force still empirical. This work compared the activation strength and internal contact of Morse taper system according to the removal force. Eighty sets, composed of implants and prosthetic abutments, were evaluated with different internal contact areas; 15.12mm2 (G3.3) and 21.25mm2 (G4.3). The specimens were activated at 0° and 30°, with loads of 10, 20, 40 and 60N. The specimens were submitted to tensile test and the data to ANOVA and Tukey's tests (α=0.05). Representative specimens were examined under SEM. Removal force of G3.3 (2.15±1.33MPa) did not differed to G4.3 (1.99±1.03MPa). The activation at 0º (2.95±0.98MPa) statistically differed to 30º (1.19±0.54MPa). The 60N load was statistically superior for G3.3 and there was no statistical difference between 20N to 60N in G4.3. The values of 10N at 30o and 20N at the long axis of the morse taper implant, independent of the frictional contact area showed the best settlement.

Resumo A longevidade da reabilitação protética é determinada pela estabilidade das interfaces implante e pilar. Conexões de cone Morse em restaurações dentárias têm se mostrado eficazes, porém a força de ativação ainda é empírica. Este trabalho comparou a força de ativação e contato interno do sistema cone Morse de acordo com a força de remoção. Oitenta conjuntos, compostos por implantes e pilares protéticos, foram avaliados com diferentes áreas de contato interno; 15,12mm2 (G3.3) e 21,25mm2 (G4.3). Os corpos-de-prova foram ativados a 0° e 30°, com cargas de 10, 20, 40 e 60N. Os corpos de prova foram submetidos ao ensaio de tração e os dados aos testes ANOVA e Tukey (α=0,05). Espécimes representativos foram examinados em MEV. A força de deslocamento do G3.3 (2,15±1,33MPa) não diferiu do G4.3 (1,99±1,03MPa). A ativação a 0º (2,95±0,98MPa) diferiu estatisticamente para 30º (1,19±0,54MPa). A carga de 60N foi estatisticamente superior para G3.3 e não houve diferença estatística entre 20N a 60N no G4.3. Os valores de 10N em 30o e 20N no longo eixo do implante cone morse, independente da área de contato friccional apresentaram o melhor assentamento.

RESUMEN

Objectives Glenoid component failure is the main cause of total shoulder arthroplasty (TSA) revision, and component design seems to influence the failure rate. The aim of the present study was to clinically and radiographically (through X-rays and computed tomography scan) evaluate the results of TSA using a minimally cemented glenoid component. Methods Total should arthroplasties performed using the minimally cemented Anchor Peg (DuPuy Synthes, Warsaw, IN, USA) glenoid component between 2008 and 2013 were evaluated. University of California at Los Angeles (UCLA) scores were calculated, and standardized plain film and computed tomography images were obtained, at a minimum follow-up of 24 months. The presence of bone between the fins of the central component peg, which indicates its integration, was assessed on the images, as well the presence of radiolucent lines around the glenoid component. Results Nineteen shoulders in 17 patients were available for evaluation. According to the UCLA score, clinical results were satisfactory in 74% of cases and fair in 21% of cases. One patient had a poor result. Component integration was found in 58% of patients (total in 42% and partial in 16%). Radiolucent lines were observed in 52% of cases. No relationship was detected between component integration and clinical results. Conclusion Satisfactory clinical results were achieved in most patients undergoing TSA using a minimally cemented glenoid component. Radiolucent lines around the glenoid component are common, but do not interfere with the clinical results. Level of evidence IV; Case series; Treatment study.

RESUMEN

A troca valvar mitral transcateter apresenta-se como uma nova opção terapêutica para o tratamento de próteses cirúrgicas degeneradas em pacientes com alto risco cirúrgico. É crescente o número de procedimentos valve-in-valve mitral ao longo dos últimos anos. O presente caso relata uma experiência inicial com esse tipo de procedimento, sendo efetivado de forma segura e eficaz em uma paciente idosa de alto risco cirúrgico para retroca valvar.

Transcatheter mitral valve replacement is a new option to treat deteriorated surgical prosthesis in high surgical risk patients. The number of valve-in-valve mitral procedures has been growing in the last few years. This case reports an initial experience with this type of procedure, safely and effectively performed in an elderly female patient with high-risk for valve replacement.

RESUMEN

Abstract Objectives Glenoid component failure is the main cause of total shoulder arthroplasty (TSA) revision, and component design seems to influence the failure rate. The aim of the present study was to clinically and radiographically (through X-rays and computed tomography scan) evaluate the results of TSA using a minimally cemented glenoid component. Methods Total should arthroplasties performed using the minimally cemented Anchor Peg (DuPuy Synthes, Warsaw, IN, USA) glenoid component between 2008 and 2013 were evaluated. University of California at Los Angeles (UCLA) scores were calculated, and standardized plain film and computed tomography images were obtained, at a minimum follow-up of 24 months. The presence of bone between the fins of the central component peg, which indicates its integration, was assessed on the images, as well the presence of radiolucent lines around the glenoid component. Results Nineteen shoulders in 17 patients were available for evaluation. According to the UCLA score, clinical results were satisfactory in 74% of cases and fair in 21% of cases. One patient had a poor result. Component integration was found in 58% of patients (total in 42% and partial in 16%). Radiolucent lines were observed in 52% of cases. No relationship was detected between component integration and clinical results. Conclusion Satisfactory clinical results were achieved in most patients undergoing TSA using a minimally cemented glenoid component. Radiolucent lines around the glenoid component are common, but do not interfere with the clinical results. Level of evidence IV; Case series; Treatment study.

Resumo Objetivos A falha do componente glenoidal é a principal causa de revisão da artroplastia total do ombro (ATO) e sua frequência parece ser influenciada pelo design do componente. O objetivo deste estudo foi a avaliação clínica e radiográfica (através de raios X e tomografia computadorizada) dos resultados da ATO com componente glenoidal minimamente cimentado. Métodos O presente trabalho analisou ATOs realizadas com componente glenoidal Anchor Peg (DuPuy Synthes, Warsaw, IN, EUA) minimamente cimentado entre 2008 e 2013. Por um período mínimo de acompanhamento de 24 meses, escores segundo critérios da University of California at Los Angeles (UCLA) e imagens padronizadas de radiografia simples e tomografia computadorizada foram analisadas. A presença de osso entre as aletas do pino do componente central, que é um indicador de sua integração, foi avaliada nas imagens, bem como a presença de linhas radiotransparentes ao redor do componente glenoidal. Resultados Dezenove ombros de 17 pacientes foram avaliados. De acordo com o escore da UCLA, os resultados clínicos foram satisfatórios em 74% dos casos e moderados em 21% dos casos. O resultado foi ruim em um paciente. A integração de componentes foi observada em 58% dos pacientes, sendo total em 42% e parcial em 16% dos casos. Linhas radiotransparentes foram observadas em 52% dos pacientes. Nenhuma relação entre a integração de componentes e os resultados clínicos foi detectada. Conclusão A maioria dos pacientes submetidos à ATO com componente glenoidal minimamente cimentado apresentou resultados clínicos satisfatórios. Linhas radiotransparentes ao redor do componente glenoidal são comuns, mas não interferem nos resultados clínicos Nível de evidência IV; Série de caso; Estudo terapêutico.

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Este estudo teve o objetivo de avaliar o comportamento biomecânico de um novo pilar protético dividido em duas peças (P2P) comparado a um pilar padrão de uma peça (P1P), ambos com indicação para coroas unitárias parafusadas de um sistema de implante de conexão cônica, submetidos a ciclagem mecânica. Foram utilizados vinte implantes instalados em cilindros de resina poliacetal e divididos em dois grupos: P1P para restaurações ao nível da plataforma do implante, de conexão cônica anti-rotacional e parafuso passante e P2P para restaurações ao nível de tecidos, constituído de duas peças, uma base sólida (P2P-B), de conexão cônica rotacional e um pilar sobre a base (P2P-P), de conexão hexagonal interna antirotacional e parafuso passante. Os corpos de prova foram testados antes e após a ciclagem mecânica (200N a 4Hz por 1x106 ciclos) através da verificação da manutenção do torque em N.cm por um torquímetro digital e da análise das micro fendas em µm na conexão implante-pilar por microscopia. O grupo P1P apresentou redução significativa no torque de remoção pós-ciclagem 10,57 (±3,63) comparado ao torque pré-ciclagem 31,63 (±0,80) e torque de remoção inicial 26,48 (±1,60). O grupo P2P-B apresentou aumento significativo no torque de remoção pós-ciclagem 41,00 (±8,64), comparado ao torque pré-ciclagem 31,10 (±0,62) e torque de remoção inicial 30,12 (±2,08), sua parte superior P2P-P apresentou redução significativa no torque de remoção pós-ciclagem 14,85 (±2,06), comparado ao torque pré-ciclagem 21,06 (±0,50), porém não apresentou diferença significativa com o torque de remoção inicial 15,51 (±1,18). Na avaliação microscópica, a conexão implante-pilar nos dois grupos apresentaram micro fendas iniciais reduzidas, P1P 4,71 (±2,12) e P2P-B 3,95 (±2,02) as quais tiveram redução significativa após a ciclagem, P1P 0,006 (±0,001) e P2P-B 0,005 (±0,001). P2P apresentou comportamento biomecânico superior ao P1P nos valores de torque pós-ciclagem, nos vários momentos comparados, suportando seu uso para coroas unitárias. A interface de conexão de ambos os pilares exibiram micro fendas reduzidas sob microscopia, as quais foram praticamente eliminadas com o acoplamento produzido pela ciclagem mecânica. (AU)

This study aimed to evaluate the biomechanical behavior of a new two-piece split prosthetic abutment (P2P) compared to a standard one-piece abutment (P1P), both indicated for screw-retained single crowns of a conical connection implant system, subjected to mechanical cycling. Twenty implants installed in polyacetal resin cylinders were used and divided into two groups: P1P for implant platform-level restorations, with an anti-rotational conical connection and through screw, and P2P for tissue-level restorations, consisting of two pieces, a solid base (P2P-B), with a rotational conical connection, and an abutment on the base (P2P-P), with an internal hexagonal anti-rotational connection and through screw. The specimens were tested before and after mechanical cycling (200 N at 4 Hz for 1x106 cycles) by checking the torque maintenance in N.cm by a digital torque meter and analyzing the microgaps in µm in the implant-abutment connection by microscopy. The P1P group showed a significant reduction in post-cycling removal torque 10.57 (±3.63) compared to precycling torque 31.63 (±0.80) and initial removal torque 26.48 (±1.60). The P2P-B group showed significant increase in post-cycling removal torque 41.00 (±8.64), compared to pre-cycling torque 31.10 (±0.62) and initial removal torque 30.12 (±2.08), its top the P2P-P showed significant decrease in post-cycling removal torque 14.85 (±2.06), compared to pre-cycling torque 21.06 (±0.50), but showed no significant difference with the initial removal torque 15.51 (±1.18). In the microscopic evaluation, the implant-abutment connection in both groups showed reduced initial microgaps, P1P 4.71 (±2.12) and P2P-B 3.95 (±2.02), which had significant reduction after cycling, P1P 0.006 (±0.001) and P2P-B 0.005 (±0.001). The P2P showed superior biomechanical behavior than the P1P abutment in post-cycling torque values at the various comparative times, supporting its use for single crowns. The connection interface of both abutments exhibited reduced microgaps under microscopy, which were practically eliminated with the coupling produced by mechanical cycling. (AU)

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Atualmente, devido a perda do elemento dentário e a procura por um tratamento estético e principalmente funcional, a reabilitação com próteses sobre implante tem sido amplamente empregada, com elevada previsibilidade a longo prazo. Com isso, muito tem sido relatado na literatura acerca das possíveis complicações dessa modalidade de tratamento, principalmente relacionado às possibilidades de falhas mecânicas das próteses implantossuportadas. Por isso, o objetivo do presente projeto foi avaliar a influência na adaptação marginal e interna, da utilização do intermediário protético e do tipo de retenção das próteses (parafusada e cimentada) em implantes cone morse submetidos à ciclagem mecânica. Foram confeccionados 40 corpos de prova, no qual cada um tinha a presença de um implante, com as dimensões de 4mm de diâmetro e 11,5mm de comprimento cone morse (n = 40). Dessa forma, foi avaliado a influência da utilização do intermediário e dos sistemas de retenção em cada conexão de maneira específica. Metade dos corpos de prova de cada sistema de conexão foram confeccionados em UCLA (n=20, sendo 10 parafusadas e 10 cimentadas), enquanto que a outra metade foi utilizado um intermediário pré-fabricado (Pilar Universal (n=20, sendo 10 parafusadas e 10 cimentadas). Os corpos de prova foram submetidos à ciclagem mecânica submersos em água destilada simulando um tempo clínico de cinco anos. Além disso, foram avaliados quanto ao torque e destorque (N) e adaptação marginal e interna (µm) antes e após a ciclagem mecânica. Os dados provenientes das mensurações foram organizados em tabela em formato Excel (Microsoft Office Excel, Redmond, WA, Estados Unidos) e submetidos ao software SigmaPlot (SigmaPlot, San Jose, CA, EUA) versão 12.0. Todos os dados foram analisados inicialmente com a utilização da estatística descritiva. Em seguida, os dados para intrusão (valores positivos), extrusão (valores negativos), destorque inicial, destorque final, e descimentação foram analisados em relação a distribuição de normalidade (teste Shapiro-Wilk e igualdade de variância) e, posteriormente, foi adotada a Análise de Variância (ANOVA) a um fator (Grupos diferentes materiais: G1 a G4), quando houve normalidade dos dados, o pós teste de Tukey foi adotado para as comparações múltiplas, quando não foi identificado uma distribuição normal, empregou-se o teste de Kruskall-Wallis e pós-teste de Dunn's ou Tukey, semelhantemente foi realizada a análise específica das variáveis pilares (UCLA e Pilar Universal) e sistemas de retenção (Parafusado e Cimentado). Para todos os testes aplicou-se nível de significância de 5% (α=0,05). A análise gráfica foi considerada através de um gráfico de barras para os dados que apresentaram normalidade com valores de média e desvio padrão, e as demais análises que não apresentaram normalidade foi considerado a confecção de um boxplot para cada grupo comparativo. As próteses sobre implante utilizando pilares em zircônia tem ganhado cada vez mais espaço, além do estudo in vitro, foi realizada uma revisão sistemática para comparar a perda óssea marginal e as complicações próteticas de reabilitações utilizando pilares de zircônia cimentado e parafusado. Em relação as próteses cimentadas e parafusadas, devido as evidências conflitantes e a presença de muitas revisões sistemáticas sobre o tema, foi realizada uma overview de revisões sistemáticas, com o objetivo de compilar as informações disponiveis e avaliar a qualidade metodologica desses estudos a respeito das complicações presentes nas próteses sobre implante cimentadas ou parafusadas(AU)

Currently, due to the loss of the dental element and the search for an aesthetic and mainly functional treatment, rehabilitation with implant prostheses has been widely used, with high long-term predictability. Thus, much has been reported in the literature about the possible complications of this treatment modality, mainly related to the possibility of mechanical failure of implant-supported prostheses. Therefore, the objective of the present project was to evaluate the influence on the marginal and internal adaptation, the use of the prosthetic intermediate and the type of retention of the prostheses (screwed and cemented) in morse taper implants submitted to mechanical cycling. 40 specimens were made, in which each one had an implant, with dimensions of 4 mm in diameter and 11.5 mm in length (n = 40). In this way, the influence of the use of intermediaries and retention systems in each connection was evaluated in a specific way. Half of the specimens of each connection system were made in UCLA (n=20, being 10 screwed and 10 cemented), while the other half was used a prefabricated intermediate (Universal Abutment (n=20, being 10 screwed) and 10 cemented). The specimens were submitted to mechanical cycling submerged in distilled water simulating a clinical time of five years. In addition, they were evaluated for torque and detorque (N) and marginal and internal adaptation (µm) before and after mechanical cycling. Data from measurements were organized in a table in Excel format (Microsoft Office Excel, Redmond, WA, USA) and submitted to SigmaPlot software (SigmaPlot, San Jose, CA, USA) version 12.0. All data were initially analyzed using descriptive statistics. Then, data for intrusion (positive values), extrusion (negative values), initial detorque, final detorque, and debonding were analyzed in relation to dist determination of normality (Shapiro-Wilk test and equality of variance) and, later, the one-way Analysis of Variance (ANOVA) was adopted (Different material groups: G1 to G4), when there was normality of the data, the Tukey post test was adopted for multiple comparisons, when a normal distribution was not identified, the Kruskall-Wallis test and Dunn's or Tukey post-test were used, similarly the specific analysis of the pillar variables (UCLA and Universal Pillar) and systems retainer (Screwed and Cemented). For all tests, a significance level of 5% (α=0.05) was applied. The graphical analysis was considered through a bar graph for the data that presented normality with mean and standard deviation values, and the other analyzes that did not present normality was considered the creation of a boxplot for each comparative group. Implant prostheses using zirconia abutments have gained more and more space, in addition to the in vitro study, a systematic review was performed to compare marginal bone loss and prosthetic complications of rehabilitations using cemented and screwed zirconia abutments. Regarding cemented and screw-retained prostheses, due to conflicting evidence and the presence of many systematic reviews on the subject, an overview of systematic reviews was performed, with the objective of compiling the available information and evaluating the methodological quality of these studies regarding complications present in cemented or screw-retained implant prostheses(AU)

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BACKGROUND: The aim of this retrospective study was to evaluate mid-term implant and prosthesis survival in patients with edentulous atrophic maxillae submitted to zygomatic implant-supported fixed rehabilitation and to identify possible related risk factors. METHODS: Data were collected from records of patients with edentulous atrophic maxillae, in good general health and who were rehabilitated by means of acrylic resin full-arch screw-retained prosthesis supported by at least one zygomatic implant, between the years of 2006-2017. Implant and prosthesis survival rates were calculated. The association between implant and prosthesis loss and quantitative and qualitative variables of interest was verified with t tests and Fisher's exact tests, respectively. For the significant variables in the latter, odds ratio and 95% confidence intervals were additionally calculated. RESULTS: The sample comprised 66 patients in whom 171 zygomatic implants were placed to support maxillary screw-retained full-arch prostheses. Implant and prosthesis survival rates of 94.15% and 92.4%, respectively, were observed in a mean of 3.6 years of follow-up (up to 11.7 years). Implant loss was 4.33 more likely to occur when adverse events were recorded after the procedure of implant placement (P = 0.026) and 10.31 more likely to occur in implants that had their prosthesis repaired during follow-up visits (P = 0.004). Prosthesis loss was 22.00 times more likely to occur when implants were previously lost (P < 0.001). All prostheses that were considered as failures (i.e. were replaced) had been previously submitted to laboratory repair at some point during follow-up. CONCLUSIONS: Zygomatic implant rehabilitation demonstrated to be a reliable method with good mid-term results. The occurrence of post-surgical adverse events and need for laboratory repair of the prosthesis were found to be significant risk factors for implant loss. Previous implant loss was significantly associated with prosthesis loss. These risk factors may be prevented by means of detailed planning of the rehabilitation to be carried out, including post-operative care of the patients, so that treatment success using zygomatic implants can be achieved.

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Introducción: Gracias a su eficiencia y al uso exclusivo de cerámicas libres de metal, en rehabilitación oral se ha logrado alcanzar los estándares estéticos y mecánicos, manteniendo o, incluso, superando, la calidad de los tratamientos en comparación con las restauraciones metal cerámicas tradicionales. Actualmente los mecanismos de confeccion de cerámica libre están evolucionando cada vez mas hacia las tecnologías maquinadas CAD-CAM y disminuyendo su producción mediante la técnica de Inyeccion PRESS. Objetivo: Comparar la tasa de supervivencia de prótesis fija unitaria realizadas con cerámicas feldespáticas convencionales y reforzadas con disilicato de litio, confeccionadas con sistema CAD/CAM de CEREC® chair-side, en comparación con el método de inyección de laboratorio PRESS convencional de prensión. Métodos: Revisión sistemática realizada a través de búsqueda de evidencia científica en PubMed, PubMed Clinical Queries, Epistemónikos, Tripdatabase, Cochrane Library, recursos electrónicos de la Universidad de los Andes y bibliografía retrógrada, de artículos publicados hasta el año 2019. Se incluyeron todos aquellos estudios referentes a prótesis fija unitaria de cerámicas feldespática convencional y feldespática reforzada con disilicato de litio, confeccionadas mediante CAD/CAM y/o método convencional. Resultados: Un total de 28 artículos cumplieron los criterios de inclusión: 21 estudios observacionales de cohorte, 4 ensayos clínicos aleatorizados y 3 no aleatorizados. A corto y mediano plazo, CAD/CAM de CEREC® registró tasas de supervivencia de 98 por ciento y 91,9 por ciento, respectivamente. El sistema convencional registró tasas de supervivencia de 97,5 por ciento a corto plazo y 93 por ciento a mediano. Conclusiones: A corto plazo se describe en la literatura que CAD/CAM de CEREC® tuvo una tasa de supervivencia ligeramente superior al sistema convencional. Por otro lado, a mediano plazo CAD/CAM de CEREC® presentó una leve disminución respecto al sistema convencional. Aún no hay estudios disponibles para determinar la supervivencia clínica de los tratamientos a largo plazo(AU)

Introduction: Thanks to its efficiency and the exclusive use of metal-free ceramics, in oral rehabilitation it has been possible to achieve aesthetic and mechanical standards, maintaining or even exceeding the quality of the treatments compared to traditional metal-ceramic restorations. Currently, free ceramic manufacturing mechanisms are increasingly evolving towards CAD-CAM machined technologies and decreasing their conventional production through the PRESS Injection technique. Objective: Compare the survival rate of single-unit fixed prostheses made with conventional feldspathic ceramics and reinforced with lithium disilicate by the CEREC® CAD/CAM chairside system, with the conventional PRESS laboratory injection method. Methods: A systematic review was conducted of scientific evidence included in papers published until the year 2019 in PubMed, PubMed Clinical Queries, Epistemonikos, Tripdatabase, Cochrane Library, electronic resources of Los Andes Peruvian University, and retrograde bibliography. The papers selected dealt with conventional and lithium-disilicate reinforced feldspathic ceramic single-unit prostheses made by CAD/CAM and/or the conventional method. Results: A total 28 papers met the inclusion criteria. Of these, 21 were observational cohort studies, four were randomized clinical assays and three were non-randomized assays. Short- and mid-term, CEREC® CAD/CAM achieved survival rates of 98 percent and 91.9 percent, respectively. The conventional system achieved survival rates of 97.5 percent short-term and 93 percent mid-term. Conclusions: As described in the literature, CEREC® CAD/CAM had a slightly higher survival rate than the conventional system in the short term. In the medium term, however, CEREC® CAD/CAM displayed a slight reduction in comparison with the conventional system. No studies are available to determine the clinical survival of the treatments in the long term(AU)

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Objective To evaluate the wear of polyethylene in a Brazilian ultracongruent knee prosthesis with a rotating platform (Rotaflex, Víncula, Rio Claro, SP, Brasil). Methods We used the test method with the loading and preparation parameters mentioned in the standards regulation ISO 14243-1:2009 , and the measurement methods mentioned in the standards regulation ISO 14243-2:2009 , for the evaluation of the wear behavior of a Brazilian prosthesis with a rotating platform. The equipment used for the wear test was the ISO 14243-1 gait simulator (EndoLab, Riedering, Germany). Results After 10 million cycles, the evaluation of the polyethylene wear showed a regular appearance of surface wear at a mean rate of 2.56 mg per million cycles. Conclusion The wear of the polyethylene of the evaluated prosthesis was minimal after the tests performed and with safety limits higher than those recommended by biomechanical engineering.

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Abstract Objective To evaluate the wear of polyethylene in a Brazilian ultracongruent knee prosthesis with a rotating platform (Rotaflex, Víncula, Rio Claro, SP, Brasil). Methods We used the test method with the loading and preparation parameters mentioned in the standards regulation ISO 14243-1:2009, and the measurement methods mentioned in the standards regulation ISO 14243-2:2009, for the evaluation of the wear behavior of a Brazilian prosthesis with a rotating platform. The equipment used for the wear test was the ISO 14243-1 gait simulator (EndoLab, Riedering, Germany). Results After 10 million cycles, the evaluation of the polyethylene wear showed a regular appearance of surface wear at a mean rate of 2.56 mg per million cycles. Conclusion The wear of the polyethylene of the evaluated prosthesis was minimal after the tests performed and with safety limits higher than those recommended by biomechanical engineering.

Resumo Objetivo Avaliar o desgaste do polietileno de uma prótese de joelho brasileira ultracongruente de base rotatória (Rotaflex, Víncula, Rio Claro, SP, Brasil). Métodos Utilizou-se o método de ensaio com os parâmetros de carregamento e preparação citados na norma ISO 14243-1:2009, e os métodos de medição citados na norma ISO 14243-2:2009, para a avaliação do comportamento de desgaste de uma prótese nacional com base rotatória. O equipamento utilizado para o teste de desgaste foi o simulador de marcha ISO 14243-1 (EndoLab, Riedering, Alemanha). Resultados Após 10 milhões de ciclos, a avaliação do desgaste do polietileno mostrou uma aparência regular do desgaste da superfície com taxa média de 2,56 mg por milhão de ciclos. Conclusão O desgaste do polietileno da prótese avaliada foi mínimo após os ensaios realizados e com os limites de segurança superiores aos preconizados pela engenharia biomecânica.

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RESUMEN Introducción: Existen numerosos tipos de fracaso en las restauraciones cerámicas en base de circonio, cerámicas sobre base o núcleo de circonio siendo el agrietamiento uno de los más frecuentes. Objetivo: Describir las asociaciones de los fracasos en las prótesis con núcleo de circonio y laminadas con cerámicas de recubrimiento. Métodos: Se realizó una revisión bibliográfica sobre los fracasos de la cerámica de restauraciones de circonio y sus mecanismos en MEDLINE, PubMed y SciELO. La búsqueda se orientó a artículos publicados fundamentalmente en los últimos 5 años sin hacer distinciones de idioma. Los tópicos consultados en la revisión estuvieron referidos a estudios experimentales en humanos, animales e in vitro que incluyeran los tópicos de fracaso, longevidad de restauraciones, mecanismos de fracaso, fracturas y tipos de ellas. Análisis e integración de la información: Se profundiza en el tema de los fracasos de la cerámica de restauraciones de circonio. La causa de fracaso más prevalente es el agrietamiento, en sus distintos grados que alcanzan hasta tasas de 16 por ciento a los 5 años, lo que representa una causa de fracaso relevante. No existe evidencia de unión química entre el núcleo de circonio y la cerámica de revestimiento, esto explicaría la génesis de las fracturas. Conclusiones: Las complicaciones más comunes encontradas en restauraciones de núcleo de circonio recubiertas con porcelana están asociadas con el agrietamiento de la porcelana de recubrimiento, a las fracturas del núcleo de circonio que se asocian fundamentalmente a traumas y hábitos parfuncionales; la pérdida de retención y problemas endodónticos(AU)

ABSTRACT Introduction: There are numerous types of failure in zirconia-based ceramic restorations, i.e. ceramic restorations on a zirconia base or core, cracking being one of the most common. Objective: Describe the association between failure in zirconia-core and ceramic-veneered prostheses. Methods: A bibliographic review was conducted about failure in zirconia-based ceramic restorations and its mechanisms in the databases MEDLINE, PubMed and SciELO. The search was aimed at papers published in any language mainly in the last five years. Papers were searched for which referred to experimental studies in humans, animals and in vitro, and dealt with the topics of failure, longevity of restorations, failure mechanisms, fractures and their types. Data analysis and integration: The topic of failure in zirconia-based ceramic restorations was studied in depth. The leading cause of failure is cracking in its various degrees, which reaches rates of up to 16 percent at five years, a relevant failure level. No evidence was found of chemical bonding between the zirconia core and the veneering ceramic, which would otherwise explain the genesis of fractures. Conclusions: The most common complications found in zirconia-core restorations covered with porcelain are associated to cracking of the veneering porcelain, fractures in the zirconia core mainly caused by traumas and parafunctional habits, retention loss and endodontic problems(AU)

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Resumen: Existe en la actualidad controversia acerca del mejor tratamiento para los pacientes portadores de trombosis valvular protésica. Muchos factores deben ser tenidos en cuenta al momento de decidir entre la resolución quirúrgica o el tratamiento con fibrinolíticos sistémicos. Las guías americanas recomiendan en plano de igualdad ambas terapéuticas, poniendo énfasis en el análisis de cada caso en particular. Las guías europeas, en cambio, le dan mayor nivel de recomendación a la cirugía, dejando la fibrinólisis para aquellos pacientes con alto riesgo quirúrgico. Se presenta el caso de una paciente de 54 años, portadora de prótesis mitral mecánica implantada hace 15 años, disfuncionante, en clase funcional II de la New York Heart Association, y se discuten las opciones diagnósticas y terapéuticas.

Summary: There is ongoing debate regarding the optimal treatment for patients with prosthetic valve thrombosis. Several issues must be taken into consideration before defining either surgical or fibrinolytic treatment. North American guidelines place both therapeutic modalities under the same recommendation grade with special emphasis on the analysis of each individual case. European guidelines place surgical treatment as the preferred option except in patients with high surgical risk. Thereby, we present the clinical case of a 54 year old female with dysfunctional mechanical mitral prosthesis implanted 15 years ago and functional class II of the New York Heart Association. Diagnostic and therapeutic approaches are discussed.

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ABSTRACT Objective: To assess the clinical and radiographic outcomes of hip resurfacing arthroplasty for the treatment of hip osteoarthritis. Methods: This study retrospectively assessed 30 patients with hip osteoarthritis who underwent hip resurfacing arthroplasty between 2005 and 2014. Patients of both genders suffering from advanced primary and secondary hip osteoarthritis were included in the study. Data were collected about postoperative complications and the need for revision of the arthroplasty. Antero-posterior pelvis and lateral hip x-rays were performed in order to classify osteolysis according to the Amstutz criteria; the Lequèsne index of severity for osteoarthritis of the hip and the UCLA activity level questionnaires were answered pre- and postoperatively. Results: After a mean follow-up of eight years, a statistically significant improvement was observed between the mean of the outcomes of both scores, when compared pre- and postoperatively (p < 0.001). Nevertheless, there was a high incidence of arthroplasty revision (20%), related to the size of the femoral stem and errors in surgical technique. Conclusion: Using the appropriate technique, hip resurfacing arthroplasty can present good results in well-selected patients.

RESUMO Objetivo: Avaliar o resultado clínico e radiográfico dos pacientes submetidos à prótese de recapeamento de quadril para o tratamento da osteoartrose de quadril. Métodos: Foram avaliados retrospectivamente 30 pacientes com coxartrose tratados com prótese de recapeamento de quadril entre 2005 e 2014. Foram incluídos no estudo pacientes de ambos os sexos portadores de osteoartrose de quadril avançada, primária ou secundária. Foram coletados dados sobre complicações pós-operatórias e necessidade de revisão da prótese. Foram feitas radiografias AP de bacia e perfil de quadril para classificação da osteólise segundo os critérios de Amstutz; os questionários do escore funcional de Lequèsne e do nível de atividade física do escore UCLA foram aplicados nos períodos pré e pós-operatórios. Resultados: Após um seguimento médio de oito anos, observou-se melhoria estatisticamente significativa entre as médias dos resultados pré e pós-operatórios de ambos os escores (p < 0,001). Entretanto, foi observada uma elevada taxa de revisão das próteses (20%), correlacionada ao tamanho do componente femoral usado e à falha na técnica cirúrgica. Conclusão: A prótese de resurfacing de quadril pode proporcionar bons resultados, com a técnica adequada, em pacientes selecionados.

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OBJECTIVE: To assess the clinical and radiographic outcomes of hip resurfacing arthroplasty for the treatment of hip osteoarthritis. METHODS: This study retrospectively assessed 30 patients with hip osteoarthritis who underwent hip resurfacing arthroplasty between 2005 and 2014. Patients of both genders suffering from advanced primary and secondary hip osteoarthritis were included in the study. Data were collected about postoperative complications and the need for revision of the arthroplasty. Antero-posterior pelvis and lateral hip x-rays were performed in order to classify osteolysis according to the Amstutz criteria; the Lequèsne index of severity for osteoarthritis of the hip and the UCLA activity level questionnaires were answered pre- and postoperatively. RESULTS: After a mean follow-up of eight years, a statistically significant improvement was observed between the mean of the outcomes of both scores, when compared pre- and postoperatively (p < 0.001). Nevertheless, there was a high incidence of arthroplasty revision (20%), related to the size of the femoral stem and errors in surgical technique. CONCLUSION: Using the appropriate technique, hip resurfacing arthroplasty can present good results in well-selected patients.

OBJETIVO: Avaliar o resultado clínico e radiográfico dos pacientes submetidos à prótese de recapeamento de quadril para o tratamento da osteoartrose de quadril. MÉTODOS: Foram avaliados retrospectivamente 30 pacientes com coxartrose tratados com prótese de recapeamento de quadril entre 2005 e 2014. Foram incluídos no estudo pacientes de ambos os sexos portadores de osteoartrose de quadril avançada, primária ou secundária. Foram coletados dados sobre complicações pós-operatórias e necessidade de revisão da prótese. Foram feitas radiografias AP de bacia e perfil de quadril para classificação da osteólise segundo os critérios de Amstutz; os questionários do escore funcional de Lequèsne e do nível de atividade física do escore UCLA foram aplicados nos períodos pré e pós-operatórios. RESULTADOS: Após um seguimento médio de oito anos, observou-se melhoria estatisticamente significativa entre as médias dos resultados pré e pós-operatórios de ambos os escores (p < 0,001). Entretanto, foi observada uma elevada taxa de revisão das próteses (20%), correlacionada ao tamanho do componente femoral usado e à falha na técnica cirúrgica. CONCLUSÃO: A prótese de resurfacing de quadril pode proporcionar bons resultados, com a técnica adequada, em pacientes selecionados.