Accuracy of Conventional and 3D-Printed Casts for Partial Fixed Prostheses.

PURPOSE: To evaluate and compare the accuracy of conventional and 3D-printed casts using five different 3D printers. MATERIALS AND METHODS: In the control group (CG group, n = 5), five conventional impressions using light- and heavy-body polyvinyl siloxane were obtained from the master model, resulting in five stone models. In the test groups, five different scans were performed by a well-trained and experienced clinician using a TRIOS intraoral scanner. All data were exported in STL file format, processed, and sent to five 3D printers. Five casts were manufactured in each printer group: SG (CARES P20, Straumann); FG (Form 2, Formlabs); WG (Duplicator 7, Wanhao); ZG (Zenith D, Zenith); and MG (Moonray S100, Moonray). Measurements of the accuracy (trueness and precision) of the casts obtained from conventional elastomeric impressions and 3D-printing methods were accomplished using a 3D analysis software (Geomagic Control). RESULTS: The FG group showed the lowest values for trueness (indicating a value closer to real dimensions), which were similar to the SG group only (P > .05). MG, WG, and ZG groups presented higher values and were similar compared to each other. Data on precision demonstrated that all 3D-printed groups showed lower values for precision (smaller deviation) when compared to the CG. CONCLUSIONS: The trueness depends on the chosen 3D printer. All of the tested 3D printers were more precise than cast models obtained from conventional elastomeric impressions.

Accuracy of conventional and 3D printed casts for partial fixed prosthesis.

PURPOSE: To evaluate and compare the accuracy of conventional and 3D-printed casts using five different 3D printers. MATERIALS AND METHODS: In the control group (CG group, n = 5), five conventional impressions using light- and heavy-body polyvinyl siloxane were obtained from the master model, resulting in five stone models. In the test groups, five different scans were performed by a well-trained and experienced clinician using a TRIOS intraoral scanner. All data were exported as an STL file format, processed, and sent to five 3D printers. Five casts were manufactured in each group: SG (CARES P20, Straumann); FG (Form 2, Formlabs); WG (Duplicator 7, Wanhao); ZG (Zenith D, Zenith); and MG (Moonray S100, Moonray). Measurements of the accuracy (trueness and precision) of the casts obtained from conventional elastomeric impressions and 3D-printing methods were accomplished using a 3D analysis software (Geomagic Control). RESULTS: The FG group showed the lowest values for trueness (closer to real dimensions), which were similar to the SG group only (P > .05). Groups MG, WG, and ZG presented higher values and were similar compared to each other. Data on precision demonstrated that all 3D-printed groups showed lower values for precision (smaller deviation) when compared to the control group. CONCLUSION: The trueness depends on the chosen 3D printer. All of the tested 3D printers were more precise than cast models obtained from conventional elastomeric impressions.

Digital and Analog Analysis of Occlusion in Conventional and Implant-Retained Complete Dentures: Preliminary Results of a Prospective Clinical Trial.

PURPOSE: To digitally evaluate the static and dynamic occlusion of patients treated with both removable conventional complete dentures (CCDs) and implant-retained removable overdentures (IODs) and to correlate two different methods of occlusal analysis. MATERIALS AND METHODS: Eleven totally edentulous patients were treated with bimaxillary CCDs. Later, mandibular CCDs were replaced by IODs retained by either two or four implants. The distribution of the occlusal contacts in static and dynamic occlusion was compared by means of the digital method (DM; T-Scan III) and the analog method (AM; articulating paper). Scores 0, 1, and 2 were assigned for inadequate, satisfactory, and adequate distribution of the occlusal contacts, respectively. The frequencies of scores were compared in relation to the types of denture by means of Fisher exact test (P < .05). The correlation between methods was assessed by means of the kappa agreement coefficient (κ) and the correlation coefficient phi (φ) (P < .05). RESULTS: Significant differences between CCDs and IODs were found in the right lateral mandibular movement (DM, P = .024; AM, P = .008), as well as in the left lateral mandibular movement (DM, P = .035). The methods of analysis of the occlusion showed a moderate agreement (κ = 0.604; P < .001) and a moderate correlation (φ = 0.605; P < .001). CONCLUSION: The digital and analog methods showed a significant agreement and moderate correlation, irrespective of the type of complete denture. The T-Scan III digital system seems to be a consistent and reproducible method to analyze occlusion.

A realização de supersérie em uma sessão completa de treinamento impacta no volume e percepção subjetiva de esforço de praticantes de musculação / La realización de una superserie en una sesión completa de entrenamiento influye en el volumen y percepción subjetiva de esfuerzo de practicantes de musculación / Performing a superset in a complete training session impact on volume and rate of perceived exertion of resistance training practitioners

Objetivo: Comparar os protocolos tradicional e supersérie, com intervalo de recuperação equiparado, quanto ao volume total de treinamento (número de repetições x peso), número total de repetições por exercício e percepção subjetiva de esforço em uma sessão de treinamento.Método: Dezesseis homens treinados realizaram de forma randomizada os protocolos. No protocolo tradicional foram executadas três séries com intervalos de dois minutos entre séries e três minutos entre exercícios. No protocolo supersérie, 30 segundos após o término de cada série, o voluntário realizava o outro exercício. Depois de finalizado o segundo exercício da supersérie, o voluntário aguardava o término do intervalo (dois minutos) para reiniciar o primeiro exercício da supersérie.Resultados: Verificou-se maior volume total de treinamento no protocolo tradicional em comparação ao supersérie (p = 0.003). Adicionalmente, no protocolo tradicional os voluntários realizaram maior número de repetições (p < 0.05) em cinco dos oito exercícios. Com relação à percepção subjetiva de esforço, os participantes relataram maiores valores de esforço no protocolo supersérie quando comparado ao protocolo tradicional (p = 0.017).Conclusão: Foi observada redução no volume total de treinamento com a utilização do protocolo supersérie, comparado ao protocolo tradicional, em uma sessão de treinamento na musculação. Adicionalmente, houve uma maior percepção subjetiva de esforço dos sujeitos no protocolo supersérie. Sendo assim, a aplicação do protocolo tradicional torna-se uma alternativa eficiente quando o objetivo é priorizar o volume de treinamento. (AU)

Objetivo: Comparar el protocolo tradicional y el de superserie, con pausa equiparada, en cuanto al volumen total de entrenamiento (número de repeticiones x peso), número total de repeticiones por ejercicio y percepción subjetiva de esfuerzo, en una sesión de entrenamiento.Método: Dieciséis hombres entrenados realizaron de forma aleatorizada los protocolos. En el protocolo tradicional se realizaron tres series con intervalos de dos minutos entre las series y tres minutos entre los ejercicios. En el protocolo de superserie, 30 segundos después de finalizada cada serie, el voluntario realizaba el otro ejercicio. Después de finalizado el segundo ejercicio de la superserie, el voluntario aguardaba el final del intervalo (dos minutos) para reiniciar el primer ejercicio de la superserie.Resultados: Se verificó mayor volumen total de entrenamiento en el protocolo tradicional en comparación con el protocolo superserie (p = 0.003). Adicionalmente, en el protocolo tradicional, los voluntarios realizaron mayor número de repeticiones (p < 0.05) en cinco de los ocho ejercicios de la sesión de entrenamiento. En cuanto a la percepción subjetiva de esfuerzo los participantes reportaron mayores valores de esfuerzo en el protocolo superserie comparado con el protocolo tradicional (p = 0.017).Conclusión: Se observó reducción en el volumen total de entrenamiento con la utilización del protocolo superserie, comparado al protocolo tradicional, en una sesión completa de entrenamiento de musculación. Adicionalmente, hubo una mayor percepción subjetiva de esfuerzo de los sujetos en el protocolo superserie. Por lo tanto, la aplicación del protocolo tradicional se convierte en una alternativa eficiente cuando el objetivo es priorizar el volumen de entrenamiento. (AU)

Objective: To compare the traditional protocol and supersets, with equal rest interval, on volume load (number of repetitions x load), total number of repetitions per exercise, and rating of perceived exertion in a training session.Method: Sixteen resistance trained men randomly performed the protocols. In traditional protocol, three sets were performed with rest intervals of two minutes between sets and three minutes between exercises. In the superset protocol, 30 seconds after the end of each set, the subject performed the other exercise. After completing the second exercise of the superset, the volunteer waited for the end of the rest intervals (two minutes) to restart the first exercise of the superset.Results: There was a higher total training volume in traditional protocol compared to superset protocol (p = 0.003). Additionally, in traditional protocol, the volunteers performed a greater number of repetitions (p < 0.05) in five of the eight exercises of the training session. Regarding the median rating of perceived exertion of the training session, it was verified that the participants reported higher effort values in the superset protocol when compared to the traditional protocol (p = 0.017).Conclusion: A reduction in the total volume of training was observed with the use of the superset protocol alternated by body segment, compared to the traditional protocol, in a complete resistance training session. Additionally, there was a higher rating of perceived exertion of the subjects in the superset protocol. Thus, the application of the traditional protocol becomes an efficient alternative when the goal is to prioritize the training volume. (AU)