Consensos referidos a conceptos rehabilitadores en la enseñanza de la odontología. Parte I: conceptos generales y diseño de la prótesis parcial removible / Consensus referring rehabilitative concepts in the teaching of dentistry. Part I: general concepts and design of removable partial prosthesis

En este artículo se desarrolla el consenso alcanzado entre profesores, referido a los conceptos generales, componentes y la secuencia del diseño de la prótesis parcial removible, durante la formación del odontó-logo en el ámbito de la Facultad de Odontología de la Universidad de Buenos Aires (AU)

This article develops the consensus between professors on the general concepts, components, and the sequence of the design of the partial removable prosthesis during the training of the dentist in the field of the Faculty of Dentistry of the University of Buenos Aires (AU)

Tasa de supervivencia de prótesis fija unitaria de cerámica feldespática y feldespática reforzada / Survival rate of feldspathic and reinforced feldspathic ceramic single-unit fixed prostheses

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)

ULTRA Tomografia Computadorizada Multidetectores com ultra baixa dose de radiação e impressão 3D como auxiliares para cirurgia guiada em implantodontia / Ultra-low dose Multidetector CT and 3D printing as aids to guided implant surgery

Objetivo: relatar um caso clínico de reabilitação com implante dentário imediato realizado utilizando Tomografia Computadorizada Multidetectores (TCMD) com ultra baixa dose de radiação, software de código aberto para manipulação das imagens e impressão 3D de baixo custo do guia cirúrgico. Relato de caso: paciente, sexo masculino, 50 anos de idade, foi avaliado clinicamente relatando dor na região do dente 45, com suspeita de fratura radicular. Como complemento ao exame clínico, o paciente realizou TCMD com ultra baixa dose de radiação para avaliar a condição dentária e do tecido ósseo adjacente. Tendo sido diagnosticada fratura radicular vertical, procedeu-se ao planejamento virtual do implante e à confecção do guia cirúrgico. As imagens em formato DICOM da TCMD foram convertidas para formato STL (Stereolithography) para manipulação e confecção do guia cirúrgico virtual. Esse guia foi impresso em PLA (poliácido láctico) utilizando impressora 3D pelo método FDM (Fusão e Deposição de Material). Após a exodontia atraumática, o guia cirúrgico foi posicionado nos dentes adjacentes e o implante foi inserido. Clinicamente, o paciente encontra-se assintomático, o implante sem sinais clínicos de inflamação e a prótese em função. Uma segunda tomografia do paciente permitiu comparar de forma tridimensional a posição final do implante e o planejamento virtual, que se mostraram equivalentes. Considerações finais: a impressão 3D em PLA mostrou-se uma solução com custo acessível para a produção de guias cirúrgicos, fornecendo previsibilidade e segurança ao implantodontista.(AU)

Objective: to report a clinical case of rehabilitation with dental implant performed using ultra- -low dose Multidetector Computed Tomography (MDCT), open source software for image manipulation, and low cost 3D printing of the surgical guide. Case report: a 50-year-old male patient was clinically evaluated complaining of pain in the tooth 45, and a root fracture was suspected. As a complement to the clinical examination, the patient performed an ultra-low dose MDCT to assess the dental condition and the adjacent bone tissue. A vertical root fracture was diagnosed, and then the virtual planning of the implant and preparation of the surgical guide were performed. The DICOM images from the MDCT were converted into STL (Stereolithography) format for manipulation and confection of the virtual surgical guide. The surgical guide was printed on PLA using a 3D printer by the FDM (Fused Deposition Modeling) method. After atraumatic extraction, the surgical guide was placed in the adjacent teeth and the implant was inserted. Clinically, the patient is asymptomatic, the implant has no clinical signs of inflammation, and the prosthesis is in function. A second ultra- -low dose MDCT of the patient allowed a three-dimensional comparison of the final position of the implant and the virtual planning, which were shown to be equivalent. Final considerations: 3D PLA printing has proved to be an affordable solution for the production of surgical guides, providing predictability and safety for the implantologist.(AU)

Restabelecimento de ponto de contato em dentes com coroas totais posteriores: relato de caso / Reestablishment of contact point on teeth with posterior crowns: case report

A presença do ponto de contato é essencial para manter a saúde das estruturas periodontais, além de evitar inclinações dentárias e desgastes, conservando, assim, uma oclusão ideal. Objetivo: apresentar um relato de caso clínico com restabelecimento dos pontos de contato de forma conservadora, por meio da ortodontia e da dentística restauradora, em dentes com coroas totais. Relato de caso: paciente do gênero feminino, 69 anos de idade, compareceu à clínica odontológica da universidade com queixa de impacção alimentar e desconforto na região superior posterior direita da arcada. Foi observada clinicamente ausência do ponto de contato entre os dentes 15, 16 e 17, optando-se pelo tratamento multidisciplinar envolvendo a ortodontia e a dentística restauradora. Para isso, foram utilizados bráquetes no segundo pré-molar e no primeiro molar superior direito (dentes 15 e 16, respectivamente), e botões ortodônticos nas faces palatinas desses, e do segundo molar superior (dente 17), unidos por elástico corrente tamanho médio. Quando obtidos os pontos de contato, foi realizada a restauração do primeiro pré-molar direito (dente 17) com resina composta. Considerações finais: o uso de elásticos corrente e botões ortodônticos foi satisfatório para a obtenção de pontos de contato entre os dentes.(AU)

The presence of the proximal contact is essential to maintain the periodontal structures health, besides preventing diseases and wastes, thus preserving an ideal occlusion. Aim: the aim of this article is to present a clinical case report with restoration of the proximal contact in a conservative way, through orthodontics and restorative dentistry, in teeth with total crowns. Case report: a 69-year-old female patient attended the university dental clinic with complaint of food impaction and discomfort in the upper right posterior region of the arcade. It was clinically observed absence of the point of contact between the teeth 15, 16 and 17 and opted for the multidisciplinary treatment involving orthodontics and restorative dentistry. For this, brackets were used in the second premolar and first maxillary right molar (teeth 15 and 16, respectively), and orthodontic buttons on the palatal surfaces of the same, and on the second upper molar (tooth 17), joined by the current elastic medium size. When the proximal contact was obtained, the first right premolar restoration was performed with a composite resin. Final considerations: the use of current elastics and orthodontic buttons were satisfactory for obtaining proximal contact between these teeth.(AU)

Diseño de Sonrisa Digital / Digital Smile Desinge

Nowadays, a lot of people need in reconstruction of the teeth in connection with their loss. Before prosthetics or any other manipulations, a person wants to quickly see the aesthetic appearance of his future tooth. At the moment, many dentists use the option of verbal explanation to the patient, what will look like a smile or a front row of teeth after treatment, but the visual representation of the person remains aside. But now this can be achieved with the help of "Digital smile design", which shows the person the final result of the dentition. This technology has a number of advantages. Some of them are the rapid creation of a prototype model and high accuracy in the manufacture of work. Thanks to these technologies, communication between the specialist and the patient has been facilitated. The digital smile design has simplified the doctor's work process and reduced patient data processing time. From now on, achieving aesthetic results in the reconstruction of teeth for the dentist is not a problem.

Comparação das medidas extraorais com as medidas intraorais na confecção da prótese total / Comparison of the extra-oral measurements with the intra-oral measurements in the manufacture of the total prosthesis

Introdução: o edentulismo é um problema bastante comum, e o conhecimento adequado da anatomia e da fisiologia da cavidade oral é essencial na recuperação e no equilíbrio neuromuscular do sistema estomatognático. O uso das linhas de referência juntamente com o plano oclusal orientam o posicionamento dos dentes artificias, que são utilizados para construção das próteses totais. Objetivo: comparar as medidas extraorais com as intraorais da largura dos dentes anteriores com as medidas das linhas de referências preconizadas na literatura para confecção de uma prótese total. Métodos: estudo do tipo observacional transversal, com amostra não probabilística, com 50 indivíduos de ambos os gêneros, no quais se realizou uma análise dentária e facial com auxílio de fotografias e um paquímetro digital. Resultados: foi observado que, na maioria dos indivíduos, não houve coincidência entre a largura dos dentes e as linhas de referência analisadas, que as mulheres apresentaram menor coincidência entre os dentes e a largura da asa do nariz, quando comparadas com os homens (8,3% e 91,7%, respectivamente), com p = 0,001. Conclusão: as linhas de referência não foram coincidentes com o tamanho dos dentes na maioria dos casos avaliados. (AU)

Introduction: edentulism is a fairly common problem, and adequate knowledge of the anatomy and physiology of the oral cavity is essential in the recovery and neuromuscular balance of the stomatognathic system. The use of reference lines together with the occlusal plane guide the positioning of the artificial teeth, which are used to construct the total dentures. Objective: to compare the extra-oral and intra-oral measurements of the width of the anterior teeth with the measurements of the reference lines recommended in the literature for making a total prosthesis. Methods: cross-sectional observational study with a non-probabilistic sample, with 50 individuals of both sexes, where a dental and facial analysis was carried out using photographs and a digital caliper. Results: it was observed that most of the individuals analyzed did not coincide between the width of the teeth and the reference lines, and that the analyzed women showed less coincidence between teeth and the width of the nose wing when compared with men (8.3% and 91.7%, respectively), with p = 0.001. Conclusion: the reference lines did not coincide with tooth size in most cases analysed. (AU)

Morse taper performance: A finite element analysis study

OBJECTIVES: To evaluate and compare the magnitude and distribution of stresses generated on implants, abutments and first molar metal-ceramic crowns using finite element analysis. METHODS: Preliminary three-dimensional models were created using the computer-aided design software SolidWorks. Stress and strain values were observed for two distinct virtual models: model 1 - Morse taper and solid abutment; model 2 - Morse taper and abutment with screw. A load (250 N) was applied to a single point of the occlusal surface at 15° to the implant long axis. Von Mises stresses were recorded for both groups at four main points: 1) abutment-retaining screws; 2) abutment neck; 3) cervical bone area; 4) implant neck. RESULTS AND CONCLUSION: Model 1 showed a higher stress value (1477.5 MPa) at the abutment-retaining screw area than the stresses found in model 2 (1091.1 MPa for the same area). The cervical bone strain values did not exceed 105 µm for either model.

Análise de tensões pelo método dos elementos finitos em implantes dentários com plataforma cone morse / Finite element stress analysis in morse cone platform dental implants

A previsão do comportamento mecânico de implantes dentários inclinados é um fator importante na área odontológica e o Método dos Elementos Finitos (MEF) é considerado uma ferramenta para esse fim. Objetivo: analisar a distribuição de tensões e deslocamentos em implantes cônicos do tipo cone morse com 3,5 mm de diâmetro e pilares com 4,8 mm e 3,8 mm de diâmetro, submetidos a carregamentos de compressão (100 N e 200 N), inclinados a 20º e 45º com base de aço inoxidável e osso cortical via MEF. Materiais e método: utilizaram-se dois modelos tridimensionais de implantes e pilares instalados de forma inclinada a 20º e 45º, os quais foram submetidos a carregamentos de compressão no sentido vertical para baixo (eixo ­ Y). Resultados: as tensões máximas de von Mises apresentaram valores superiores para geometrias com inclinação de 45º e carregamento de 200 N. Foi possível verificar ainda que os resultados para implantes submetidos ao carregamento de 100 N a 45º apresentaram valores superiores (574,16 MPa), quando comparado com dados da literatura, com diferença de 8,7%. O mesmo pôde ser verificado para resultados de deslocamento, onde o conjunto de implantes-pilares com inclinação maior (45º) apresentou maiores valores, quando comparados com implantes-pilares com inclinação menor (20º). Conclusão: foi possível certificar via MEF que as maiores tensões são obtidas para carregamentos com inclinações maiores, sendo que o mesmo ocorre para valores de deslocamento. O MEF demonstrou ser uma alternativa viável na área odontológica para prever o comportamento mecânico de implantes dentários.(AU)

Predicting the mechanical behavior of tilted implants is an important factor in the field of dentistry, and the Finite Element Analysis (FEA) is a tool for such purpose. Objective: To analyze the distribution of stresses and displacements in conical Morse cone implants with 3.5 mm of diameter and abutments with 4.8 mm and 3.8 mm of diameter, subjected to compression loads (100 N and 200 N), tilted at 20º and 45º with stainless steel base material and cortical bone, using FEA. Materials and method: Two three-dimensional models of implants and abutments tilted at 20º and 45º were used, and they were subjected to vertical downward compression loads (Y­axis). Results: Maximum von Mises stresses presented higher values for the 45º inclination and 200 N load. It was also verified that the results for implants subjected to a load of 100 N and implants tilted at 45º presented higher stress values (574.16 MPa) than literature data, with a difference of 8.7%. This was also observed for displacement results, in which implant- abutment assemblies with greater inclination (45º) presented higher values than implant-abutments with smaller inclination (20º). Conclusion: The FEA showed that higher stress values were obtained when compression loads were applied to greater inclinations. This also occurred for displacement results. The FEA represented a viable alternative in the field of dentistry to predict the mechanical behavior of dental implants.(AU)

Padrão de oclusão em prótese Protocolo de Brånemark: uma revisão de literatura / Standard of occlusion in Brånemark Protocol prothesis: a literature review

O padrão oclusal pode ser considerado um fator crítico para a longevidade dos componentes do sistema estomatognático como também das reabilitações implantossuportadas. Objetivo: revisar a literatura em relação ao padrão de oclusão mais adequado para reabilitar um paciente edêntulo com prótese Protocolo de Brånemark. Revisão de literatura: nesta revisão, os artigos de estudos clínicos retrospectivos (2 artigos) e in silico (2 artigos) foram incluídos. Considerações finais: padrões de oclusão em prótese Protocolo de Brånemark são um tema muito escasso na literatura; o uso de uma oclusão mutuamente protegida com guia lateral em canino favorece a distribuição da tensão sobre os implantes e o osso alveolar; no entanto, a condição do arco antagonista pode influenciar esta escolha. (AU)

The occlusal pattern can be considered a critical factor for the longevity of the components of the stomatognathic system, as well as of the implantsupported rehabilitations. Objective: to review the literature regarding the most appropriate standard of occlusion to rehabilitate a patient edentulous with Brånemark Protocol prothesis. Literature review: in this review, articles from retrospective clinical studies (02 articles) and in silico studies (02 articles) were included. Final considerations: this literature review shows that standard of occlusion in the Brånemark Protocol prosthesis ns are a very scarce subject in the literature, the use of a mutually protected lateral guiding in canine favors the stress distribution on the implants and alveolar bone, however the condition of the arc antagonist may influence this choice. (AU)

Reabilitação oral de paciente com síndrome da combinação: relato de caso / Patient oral rehabilitation with combination syndrome: case report

Objetivo: o tratamento de pacientes desdentados com reabsorção alveolar severa é uma temática desafiadora na reabilitação protética. Identificada por Kelly em 1972, a síndrome da combinação é uma manifestação intraoral encontrada em pacientes totalmente desdentados na arcada superior, em oposição a uma prótese mandibular de extensão distal bilateral. Relato de caso: este estudo revisa e discute, por meio de um caso clínico, as características clínicas presentes em um paciente com manifestações da síndrome da combinação. Além disso, apresenta uma proposta de tratamento reabilita¬dor, restabelecendo a função fonética e a estética do paciente. Considerações finais: diagnosticar a síndrome e estabelecer um plano de tratamento adequado às necessidades do paciente, criando condições clínicas para o restabelecimento da saúde, são imprescindíveis para obter resultado e, assim, impedir o avanço do quadro clínico. (AU)

Objective: treatment of patients with reactivity with respiratory problems. Identified by Kelly in 1972, a combination syndrome and an intraoral manifestation found in fully edentulous patients in the upper arch as opposed to a mandibular prosthesis of bilateral distal extension. Case report: the present study reviews and discusses, through a clinical case, as clinical features present in a patient with manifestations of the combination syndrome, in addition, to present a proposal of rehabilitative treatment, restoring function, phonetics and esthetics to the patient. Final considerations: diagnosing a syndrome and establishing a treatment plan appropriate to the needs of the patient and creating clinical conditions for the reestablishment of health are essential to obtain the result and thus impeding the advancement of the clinical picture. (AU)

Esthetic rehabilitation with ultra-thin ceramic veneers and direct mock-up in the treatment of dental erosion ­ case report

Dental erosion is a high prevalence condition characterized by the loss of dental substance due to chemical agents. it can also be associated with physical wear, affecting function and aesthetics. ceramic veneers can provide effective solutions to patients affected by erosive disorders, by means of an indirect approach and minimal intervention. recent advances in cementation techniques and ceramic materials have allowed their use in reduced thicknesses, known as "dental contact lenses" or "ultra-thin veneers". they contribute significantly to the preservation of the dental structures, having excellent mechanical properties and providing satisfactory aesthetic solutions. their manufacture requires rigorous planning and the use of three-dimensional models or mock ups in order to preview the final outcome. case: the aim of this report is to communicate the use of this technique for the treatment and successful 12-months follow-up of a patient affected by dental erosion of the maxillary central incisors. special interest was placed on direct mock-up, which is a simple technique not requiring laboratory steps. luting of the lithium disilicate veneers was carried out with a light-curing resin cement and try-in pastes, yielding a very satisfactory result. conclusion: diagnosis and early treatment of this disorder allows the application of conservative techniques, such as ultra-thin veneers, which are seen as a promising alternative treatment to full coverage restorations and traditional ceramic veneers.

Reliability of light microscopy and a computer-assisted replica measurement technique for evaluating the fit of dental copings

Abstract The aim of this in vitro study was to assess the reliability of two measurement systems for evaluating the marginal and internal fit of dental copings. Material and Methods: Sixteen CAD/CAM titanium copings were produced for a prepared maxillary canine. To modify the CAD surface model using different parameters (data density; enlargement in different directions), varying fit was created. Five light-body silicone replicas representing the gap between the canine and the coping were made for each coping and for each measurement method: (1) light microscopy measurements (LMMs); and (2) computer-assisted measurements (CASMs) using an optical digitizing system. Two investigators independently measured the marginal and internal fit using both methods. The inter-rater reliability [intraclass correlation coefficient (ICC)] and agreement [Bland-Altman (bias) analyses]: mean of the differences (bias) between two measurements [the closer to zero the mean (bias) is, the higher the agreement between the two measurements] were calculated for several measurement points (marginal-distal, marginal-buccal, axial-buccal, incisal). For the LMM technique, one investigator repeated the measurements to determine repeatability (intra-rater reliability and agreement). Results: For inter-rater reliability, the ICC was 0.848-0.998 for LMMs and 0.945-0.999 for CASMs, depending on the measurement point. Bland-Altman bias was −15.7 to 3.5 μm for LMMs and −3.0 to 1.9 μm for CASMs. For LMMs, the marginal-distal and marginal-buccal measurement points showed the lowest ICC (0.848/0.978) and the highest bias (-15.7 μm/-7.6 μm). With the intra-rater reliability and agreement (repeatability) for LMMs, the ICC was 0.970-0.998 and bias was −1.3 to 2.3 μm. Conclusion: LMMs showed lower interrater reliability and agreement at the marginal measurement points than CASMs, which indicates a more subjective influence with LMMs at these measurement points. The values, however, were still clinically acceptable. LMMs showed very high intra-rater reliability and agreement for all measurement points, indicating high repeatability.

Corrélation entre les distances intercanthus, intercanine et la largeur du nez chez une population marocaine

Introduction : La sélection de la taille des dents antérieures maxillaires est l'une des étapes cliniques des plus importantes dans la réussite de l'esthétique de la prothèse amovible. Plusieurs études ont été réalisées pour établir des méthodes d'estimation de la largeur des dents antérieures maxillaires.Objectif : Déterminer l'existence d'une corrélation entre la largeur du nez, la distance inter-canthus interne et la distance inter-canine maxillaire, afin de faciliter le choix des dents antérieures maxillaires.Matériel et méthodes : Soixante-deux étudiants marocains de la faculté de médecine Dentaire de Casablanca âgés entre 18 et 26 ans ont été inclus dans cette étude ; La distance inter-canthus interne a été mesurée entre les angles médians de la fissure palpébrale. La largeur du nez a été mesurée entre les ailes du nez au point le plus large. La distance inter-canine maxillaire a été déterminée par voie intra-orale. Les mensurations ont été prises à l'aide d'un pied à coulisse électronique. Les coefficients de corrélation ont été calculés pour déterminer la relation entre les différents éléments (P < 0,05). Résultats : Bien que les corrélations soient non-significatives, il existe une relation significative entre la distance inter-canthus interne et la largeur du nez. Conclusion : Dans les limites de cette étude, les résultats suggèrent que la largeur du nez et la distance inter-canthus interne ne peuvent pas être utilisées pour déterminer la largeur des six dents antérieures maxillaires pour les patients édentés totaux ou partiels

Reabilitação do guia canino complementar ao tratamento harmônico e estético com prótese parcial fixa livre de metal / Rehabilitation of the canine guide complementary to the harmonic and aesthetic treatment with fixed partial denture of metal

Introdução: A reabilitação estética de dentes anteriores com próteses cerâmicas livres de metal proporciona excelência estética principalmente pela ausência da margem metálica. Pacientes que apresentam oclusão adequada e ausência de hábitos parafuncionais possuem menor chances de falhas catastróficas em movimentos excêntricos e bordejantes durante as excursões mandibulares. Objetivo: evidenciar, por meio de relato de um caso clínico, o reestabelecimento da estética e função de dentes anteriores, utilizando restaurações cerâmicas livres de metal. Conclusões: A utilização de cerâmicas livres de metal permitiu uma estética natural e funcional com ótimas propriedades ópticas, integrando as restaurações ao sorriso do paciente.(AU)

Introduction: The aesthetic rehabilitation of anterior teeth with metal-free ceramic prosthesis provides aesthetic excellence mainly due to the absence of metal margin. Patients with adequate occlusion and absence of parafunctional habits have a lower chance of catastrophic failure in eccentric movements and contours during mandibular excursions. Aim: to report, through a clinical case report, reestablishment of aesthetics and function of anterior teeth, using metal free ceramic restorations. Conclusions: The use of free metal ceramics allowed a natural and functional aesthetic with excellent optical properties, integrating the restorations to the patient's smile.(AU)

Materiales para prótesis provisionales / Materials for provisional prosthetics

Las restauraciones provisionales utilizadas en prótesis fija han cambiado y evolucionado en los últimos años como consecuencia de los recientes avances en odontología restauradora y ha pasado a ser un factor de grandes demandas y exigencias estéticas. En la actualidad la posibilidad de elección de resinas para provisionales en el mercado son diversas. Cada material con sus ventajas y desventajas.El presenta artículo aborda los materiales que en la actualidad son usados con más frecuencia para la confección de prótesis provisionales en nuestro mercado y que posibilidades nos brinda.

The provisional restorations used in fixed prostheses have changed and evolved in recent years as a result of recent advances in restorative dentistry and has become a factor of great demands and aesthetic demands. At present the possibility of choosing resins for temporary in the market are diverse. Each material with its advantages and disadvantages.This article addresses the materials that are currently used most frequently for the preparation of temporary prostheses in our market and what possibilities they provide us.

Implantes de altura reduzida devem ser esplintados em região posterior de mandíbula? / Should implants with reduced height be splinted in the posterior mandible?

A reabilitação de pacientes parcialmente desdentados é um tratamento viável e com excelente prognóstico. Todavia, a disponibilidade óssea em altura é um fator crucial para o sucesso desse tratamento. O levantamento de seio maxilar, apesar da baixa qualidade óssea da maxila posterior, é considerado um procedimento bastante previsível. Entretanto, técnicas reconstrutivas em mandíbula não possuem a mesma previsibilidade, além de apresentar maior morbidade pós-operatória. Apesar da alta previsibilidade dos implantes com altura reduzida, poucos são os estudos que avaliam a real necessidade da esplintagem do mesmo em mandíbula posterior atrófica. Dessa forma, o objetivo do presente estudo foi avaliar a necessidade de um implante curto ser esplintado a outro. Após análise criteriosa da literatura concluiu-se que os implantes com altura reduzida unitários apresentam igual previsibilidade em relação ao esplintado. Todavia, a heterogeneidade dos estudos e a falta de ensaios clínicos randomizados justifica a elaboração de novas pesquisas.(AU)

Rehabilitation of partially edentulous patients is a viable treatment with an excellent prognosis. However, bone height availability is a crucial factor in the treatment success. The maxillary sinus lift, despite poor bone quality of posterior maxilla, is considered a predictable procedure. However, reconstructive techniques in the mandible do not have the same predictability and present more postoperative morbidity. Despite the high predictability of short implants, there are few studies evaluating the real necessity for splinting implants in posterior atrophic mandible. Thus, the objective of the present study was to evaluate the need for a short implant to be splinted to another. After analysis of the literature, this review concluded that unitary short implants presented equal predictability compared to splinted implants. However, the heterogeneity of the studies and the lack of randomized clinical trials justify the development of new research.(AU)

Residual stress within the porcelain veneer of 3-unit zirconia fixed dental prostheses with different framework designs measured by nanoindentation / Estresse residual na porcelana de revestimento de próteses parciais fixas de 3 elementos com diferentes desenhos de infraestrutura mensurado por nanoendentação

The present study aimed to identify different concentrations of residual stress of surfaces of porcelain veneer (PV) fused to zirconia 3-unit fixed dental prostheses (FDPs) with even thickness and modified (lingual collar connected to proximal struts presenting 12 mm2 connector area) framework designs by nanoindentation method. Twenty-three FDPs replacing second premolar (PM) were fabricated and the cyclic loading was applied on twenty FDPs. Fractured, suspended and non-fatigued FDPs were selected and divided (n=3/each) into: 1) Fractured even thickness (ZrEvenF); 2) Suspended even thickness (ZrEvenS); 3) Fractured with modified framework (ZrModF); 4) Suspended with modified framework (ZrModS); 5) Non-fatigued even thickness (Control). Moreover, the control group surfaces could be divided (n=3/each) into: 6) Mesial PM abutment (MPMa); 7) Distal PM abutment (DPMa); 8) Buccal PM abutment (BPMa); 9) Lingual PM abutment (LPMa); 10) Mesial PM pontic (MPMp); 11) Distal PM pontic (DPMp); 12) Buccal PM pontic (BPMp); 13) Lingual PM pontic (LPMp); 14) Mesial molar abutment (MMa); 15) Distal molar abutment (DMa); 16) Buccal molar abutment (BMa); 17) Lingual molar abutment (LMa). The PV surfaces were nanoindented in regions of interest (ROI) 1, 2 and 3, which were 0.03 mm, 0.35 mm and 1.05 mm from outer PV surface surface towards the PV/framework interface, respectively. Each ROI received 5 nanoindentations with 10 µm of minimum separation loaded to a peak load 4 µN. The Linear Mixed Model test and Least Significant Difference (95%) were used. The statistical analysis among ZrEvenF, ZrEvenS, ZrModF, ZrModS, and Control groups showed differences (p=0.000) except for the comparison between ZrModS and Control group (p=0.371). Also, ROI 1, 2, and 3 were different (p<0.001) with higher residual stresses in outer PV regions relative to those closer to the framework. The comparison among crowns showed that pontic was different from premolar (p=0,001) and molar (p=0,007) abutments, always showing higher residual stress levels. When marginal ridges groups (MPMa, DPMa, MPMp, DPMp, MMa, DMa) were compared, the DMa group was different from DPMp (p=0,004) and MPMa (p=0,00) group, whereas MPMa was different among all groups. The residual stress of porcelain veneer FDPs was different between: fractured and suspended FDPs regardless of the framework design; ROI 1, 2 and 3; and pontic and abutment crowns. Moreover, the proximal areas presented the highest concentration of residual stress. (AU)

O presente estudo teve como objetivo identificar diferentes concentrações de tensão residual de superfícies da cerâmica de revestimento (CR) de próteses parciais fixas de zircônia de 3 elementos (PPFs) com desenho da infraestrutura de espessura mínima e modificada (cinta lingual conectada aos postes proximais com 12 mm2 de área de conector) pelo método de nanoindentação. Vinte e três PPFs repondo segundo premolar (PM) foram confeccionados e o carregamento dinâmico foi aplicado em vinte PPFs. As PPFs fraturadas, suspensas e não fadigadas foram selecionadas e divididas (n=3/cada) nos seguintes grupos: 1) Fraturadas com espessura mínima (ZrEvenF); 2) Suspensas com espessura mínima (ZrEvenS); 3) Fraturadas com infraestrutura modificada (ZrModF); 4) Suspensas com infraestrutura modificada (ZrModS); 5) Não fadigadas com espessura mínima (Controle). Além disso, as superfícies do grupo controle foram divididas (n=3/cada) nos seguintes grupos: 6) Mesial do pilar PM (MPMa); 7) Distal do pilar PM (DPMa); 8) Vestibular do pilar PM (BPMa); 9) Lingual do pilar PM (LPMa); 10) Mesial do pôntico PM (MPMp); 11) Distal do pôntico PM (DPMp); 12) Vestibular do pôntico PM (BPMp); 13) Lingual do pôntico PM (LPMp); 14) Mesial do pilar molar (MMa); 15) Distal do pilar molar (DMa); 16) Vestibular do pilar molar (BMa); 17) Lingual do pilar molar (LMa). As superfícies da CR foram nanoendentadas nas regiões de interesse (ROI) 1, 2 e 3, a qual a distância da superfície externa da CR no sentido da interface CR/infraestrutura era de 0,03 mm, 0,35 mm e 1,05 mm, respectivamente. Cada ROI recebeu 5 nanoendentações com espaço mínimo de 10 µm para carregar até 4 µN. O teste modelo linear misto com diferença estatística mínima (95%) foi executado usando os valores de dureza. A análise estatística entre os grupos ZrEvenF, ZrEvenS, ZrModF, ZrModS, e Control apresentou diferenças (p=0.000) exceto para a comparação entre os grupos ZrModS e Control (p=0.371). Também, ROI 1, 2 e 3 foram diferentes (p<0.001). A comparação entre coroas mostrou que o pôntico foi diferente dos pilares pré-molar (p=0,001) e molar (p=0,007), sempre apresentando os maiores níveis de tensão. Quando os grupos das cristas marginais (MPMa, DPMa, MPMp, DPMp, MMa, DMa) foram comparadas, o grupo DMa foi diferente dos grupos DPMp (p=0,004) and MPMa (p=0,00), enquanto que o grupo MPMa foi diferente de todos os grupos. A tensão residual da cerâmica de revestimento foi diferente entre: PPFs fraturadas e suspensas independente do desenho da infraestrutura; ROI 1, 2 e 3; e pônticos e pilares. Além disso, as áreas proximais apresentaram a maior concentração de tensão residual. (AU)

Comparative in vitro evaluation of CAD/CAM vs conventional provisional crowns

ABSTRACT Objective This study compared the marginal gap, internal fit, fracture strength, and mode of fracture of CAD/CAM provisional crowns with that of direct provisional crowns. Material and Methods An upper right first premolar phantom tooth was prepared for full ceramic crown following tooth preparation guidelines. The materials tested were: VITA CAD-Temp®, Polyetheretherketone “PEEK”, Telio CAD-Temp, and Protemp™4 (control group). The crowns were divided into four groups (n=10), Group1: VITA CAD-Temp®, Group 2: PEEK, Group 3: Telio CAD-Temp, and Group 4: Protemp™4. Each crown was investigated for marginal and internal fit, fracture strength, and mode of fracture. Statistical analysis was performed using GraphPad Prism software version 6.0. Results The average marginal gap was: VITA CAD-Temp® 60.61 (±9.99) µm, PEEK 46.75 (±8.26) µm, Telio CAD-Temp 56.10 (±5.65) µm, and Protemp™4 193.07(±35.96) µm (P<0.001). The average internal fit was: VITA CAD-Temp® 124.94 (±22.96) µm, PEEK 113.14 (±23.55) µm, Telio CAD-Temp 110.95 (±11.64) µm, and Protemp™4 143.48(±26.74) µm. The average fracture strength was: VITA CAD-Temp® 361.01 (±21.61) N, PEEK 802.23 (±111.29) N, Telio CAD-Temp 719.24 (±95.17) N, and Protemp™4 416.40 (±69.14) N. One-way ANOVA test showed a statistically significant difference for marginal gap, internal gap, and fracture strength between all groups (p<0.001). However, the mode of fracture showed no differences between the groups (p>0.05). Conclusions CAD/CAM fabricated provisional crowns demonstrated superior fit and better strength than direct provisional crowns.