Zirconia Implants Produced by Additive Manufacturing - A Scoping Review.

INTRODUCTION: Additive manufacturing is a tool with potential use in medicine and dentistry. The manufacture of metals and composites is already advanced, however, concerns about titanium hypersensitivity, tissue staining, and corrosion caused by gradual material degradation encourage research into more biocompatible alternatives. OBJECTIVE: This systematic scoping review aimed to gather studies that evaluated zirconia implants produced by additive manufacturing to describe the current stage of the printing technique and the final product. METHODS: Searches in Embase, PubMed, SCOPUS, Web of Science, and Google Scholar databases were enriched with manual searches between February and March 2021 and updated in June 2022 using keywords: zirconium implants, zirconium oxide, additive manufacturing, rapid prototyping, 3D printing, selective laser melting, and electron beam melting. The criteria included studies that evaluated or described zirconia implants obtained by 3D printing, with a direct relationship to dentistry or orthopedics. RESULTS: The database search resulted in 671 articles. Eight articles were selected for full reading and remained in this systematic review. CONCLUSION: The printing technique for zirconia implants is promising. However, further studies are required before implants produced by the printing technique can be tested clinically. The literature with results regarding the impression product is still limited.

CAD/CAM technology for fabrication of reduction guide for RPD parallel guiding planes preparation: A dental technique.

INTRODUCTION: The preparation of parallel axial wall guide planes in abutment teeth is essential for providing a correct path of insertion and removal axis for removable partial dentures (RPDs). With the introduction of digital resources, new alternatives to the conventional method can be used to manufacture guide preparation for guide planes. AIMS: To describe the use of computer-aided design/computer-aided manufacturing (CAD/CAM) technology for the manufacture of guide planes to guide the reduction of the axial walls of abutment teeth according to the insertion and removal axis of the RPD. METHODS: This technique used the "bite splint" module of the Dental Wings software for the virtual planning of guide planes, to promote the construction of axial walls parallel to the abutment teeth. This was performed from the virtual design on a standard tessellation language (STL) file obtained by intraoral scanning, which determined the best trajectory for insertion and removal of the metallic structure. CONCLUSION: Digital technology allows the design and production of guide planes for the preparation of abutment teeth, simplifying the conventionally used technique, with precision and speed.

Accuracy of Dental and Industrial 3D Printers.

PURPOSE: This in vitro study evaluated the dimensional accuracy of three 3D printers and one milling machine with their respective polymeric materials using a simplified geometrical model. MATERIALS AND METHODS: A simplified computer-aided design (CAD) model was created. The test samples were fabricated with three 3D printers: a dental desktop stereolithography (SLA) printer, an industrial SLA printer, and an industrial fused deposition modeling (FDM) printer, as well as a 5-axis milling machine. One polymer material was used per industrial printer and milling machine while two materials were used with the dental printer for a total of five study groups. Test specimens were then digitized using a laboratory scanner. The virtual outer caliper method was used to measure the linear dimensions of the digitized 3D printed and milled specimens in x-, y-, and z-axes, and compare them to the known values of the CAD model. Data were analyzed with Kruskal-Wallis one-way ANOVA on Ranks followed by the Tukey's test. RESULTS: Milled specimens were not significantly different from the CAD model in any dimension (p > 0.05). All 3D printed specimens were significantly different from the CAD model in all dimensions (p = 0.01), except the dental SLA 3D printer with one of the polymers tested (Bis-GMA) which was not significantly different in two (x and z) dimensions (p = 0.4 and p = 0.12). CONCLUSIONS: The milling technology tested provided greater dimensional accuracy than the selected 3D printing. Printer, printing technology, and material selection affected the accuracy of the printed model.

Initial Experience Using 3-Dimensional Printed Models for Head and Neck Reconstruction in Haiti.

This report describes the first use of a novel workflow for in-house computer-aided design (CAD) for application in a resource-limited surgical outreach setting. Preoperative computed tomography imaging obtained locally in Haiti was used to produce rapid-prototyped 3-dimensional (3D) mandibular models for 2 patients with large ameloblastomas. Models were used for patient consent, surgical education, and surgical planning. Computer-aided design and 3D models have the potential to significantly aid the process of complex surgery in the outreach setting by aiding in surgical consent and education, in addition to expected surgical applications of improved anatomic reconstruction.

Comparative Analysis of Fracture Resistance between CAD/CAM Materials for Interim Fixed Prosthesis.

The aim of this study was to evaluate and compare the resistance to fracture of interim restorations obtained through additive techniques (3D impressions) and subtractive techniques (milling) using a computer-aided design and manufacture (CAD/CAM) system of a three-unit fixed dental prosthesis (FDP) to ascertain its clinical importance. (1) Materials and methods: In total, 40 samples were manufactured and divided into two groups (n = 20) using: (1) light-curing micro hybrid resin for temporary crowns and bridges (PriZma 3D Bio Prov, MarketechLabs, São Paulo, Brazil) for the rapid prototyping group (RP) and (2) a polymethylmethacrylate (PMMA) CAD/CAM disc (Vipiblock Trilux, VIPI, São Paulo, Brazil) for the computer-assisted milling (CC). The resistance to fracture was determined with a universal testing machine. (2) Results: The strength and the standard deviation for the computer-assisted milling group were higher (1663.57 ± 130.25 N) than the rapid prototyping (RP) group, which had lower values of (1437.74 ± 73.41 N). (3) Conclusions: The provisional restorations from the computer-assisted milling group showed a greater resistance to fracture than the provisional restorations obtained from the rapid prototyping group.

3D printing of brachycephalic and dolichocephalic canine skulls and mandibles: a complement to traditional osteotechnique / Impressão 3D de esqueleto do crânio e mandíbula de cãesbraquicéfalos e dolicocéfalos: um complemento à osteotécnica tradicional

This paper aimed at reporting the creation of brachycephalic and dolichocephalic 3D synthetic anatomical models of canine heads (3D SAMCH) as a complementary technique to traditional osteotechnique using Computed Tomography (CT) images in volumetric reconstruction. The study was carried out in three stages, namely: a) preparation of canine heads in natura; b) creation of digital files of canine heads using CT; and c) 3D printing of synthetic anatomical models of canine heads. As a result, two 3D SAMCH were produced due to rarer availability in Animal Anatomy laboratories collections; the important representation of the cribriform plate was possible, but a remarkable defect presented was the teeth. It concluded that the digital files creation through CT scanner allows a fine representation of canine heads if considered pros and cons regarding the use of synthetic models instead of natural bones.

O objetivo deste trabalho foi relatar a criação de modelos anatômicos 3D sintéticos de cabeças de cães braquicé-falo e dolicocéfalo (3D SAMCH) como técnica complementar à osteotécnica tradicional por meio de imagens de Tomografia Computadorizada (TC) para reconstrução volumétrica. O estudo foi realizado em três etapas, a saber: a) preparação do esque-leto de cabeças caninas in natura; b) criação de arquivos digitais de cabeças caninas por meio da TC; e, c) impressão 3D de modelos anatômicos sintéticos de cabeças caninas. Como resultado, dois modelos 3D SAMCH foram produzidos devido à disponibilidade mais rara das respectivas peças anatômicas originais nos acervos dos laboratórios de Anatomia Animal; a importante representação da placa cribriforme foi possível, mas um defeito notável apresentado nos modelos sintéticos foram os dentes. Conclui-se que a criação de arquivos digitais por meio da tomografia computadorizada permitiu uma representação precisa das cabeças caninas se considerados os prós e os contras quanto ao uso de modelos sintéticos em vez de ossos naturais.

3D printing of brachycephalic and dolichocephalic canine skulls and mandibles: a complement to traditional osteotechnique / Impressão 3D de esqueleto do crânio e mandíbula de cãesbraquicéfalos e dolicocéfalos: um complemento à osteotécnica tradicional

This paper aimed at reporting the creation of brachycephalic and dolichocephalic 3D synthetic anatomical models of canine heads (3D SAMCH) as a complementary technique to traditional osteotechnique using Computed Tomography (CT) images in volumetric reconstruction. The study was carried out in three stages, namely: a) preparation of canine heads in natura; b) creation of digital files of canine heads using CT; and c) 3D printing of synthetic anatomical models of canine heads. As a result, two 3D SAMCH were produced due to rarer availability in Animal Anatomy laboratories collections; the important representation of the cribriform plate was possible, but a remarkable defect presented was the teeth. It concluded that the digital files creation through CT scanner allows a fine representation of canine heads if considered pros and cons regarding the use of synthetic models instead of natural bones.(AU)

O objetivo deste trabalho foi relatar a criação de modelos anatômicos 3D sintéticos de cabeças de cães braquicé-falo e dolicocéfalo (3D SAMCH) como técnica complementar à osteotécnica tradicional por meio de imagens de Tomografia Computadorizada (TC) para reconstrução volumétrica. O estudo foi realizado em três etapas, a saber: a) preparação do esque-leto de cabeças caninas in natura; b) criação de arquivos digitais de cabeças caninas por meio da TC; e, c) impressão 3D de modelos anatômicos sintéticos de cabeças caninas. Como resultado, dois modelos 3D SAMCH foram produzidos devido à disponibilidade mais rara das respectivas peças anatômicas originais nos acervos dos laboratórios de Anatomia Animal; a importante representação da placa cribriforme foi possível, mas um defeito notável apresentado nos modelos sintéticos foram os dentes. Conclui-se que a criação de arquivos digitais por meio da tomografia computadorizada permitiu uma representação precisa das cabeças caninas se considerados os prós e os contras quanto ao uso de modelos sintéticos em vez de ossos naturais.(AU)

3D printing as a diagnostic tool for congenital malformation in a brachycephalic dog / Impressão 3D como ferramenta de diagnóstico para malformação congênita em cão braquicefálico

Congenital anomalies are hereditary or acquired, and their location and intensity are determining factors for the survival of animals. Some cases are rare, often unidentified, poorly reported and of unknown etiology. This paper reports a congenital malformation in a French bulldog, demonstrating the importance of accurate diagnosis for surgical decisions. The use of new technologies such as computed tomography and rapid prototyping enables the analysis of morphofunctional changes, resulting in excellent results for clinical cases in which it is difficult to identify and scale the anatomical deformities. Through this feature, it is possible to accurately recreate anatomical structures of interest, enabling greater assertiveness in deciding the treatment to be established, whether surgical or not. Castration of animals that survive this condition due to hereditary etiology is recommended.(AU)

Anomalias congênitas possuem caráter hereditário ou adquirido, sendo que sua localização e intensidade são fatores determinantes para a sobrevivência do animal. Algumas são raras, muitas vezes não identificadas, pouco relatadas e com etiologia desconhecida. O presente trabalho registra um caso de malformação congênita em um bulldog francês, demonstrando a importância do diagnóstico preciso para a decisão cirúrgica. A utilização de novas tecnologias como tomografia computadorizada e prototipagem rápida possibilitam a análise de alterações morfofuncionais, tendo ótimo resultado para casos clínicos em que há dificuldade em identificar e dimensionar deformidades anatômicas. Através desse recurso é possível recriar com precisão estruturas anatômicas de interesse, possibilitando maior assertiva na decisão do tratamento a ser estabelecido, sendo ele cirúrgico ou não. É recomendada a castração dos animais que sobreviveram a essa condição, devido a etiologia hereditária.(AU)

3D printing of canine hip dysplasia: anatomic models and radiographs / Impressão 3D da displasia coxofemoral canina: modelos anatômicos e radiografias

Canine Hip Dysplasia (CHD) is a highly prevalent articular pathological condition. In this sense, radiography becomes an important diagnostic method to determine the presence and severity of the disease. The objective was to create 3D models and their respective radiographs representing the CHD (3D AMCHD). The research was carried out in the Laboratory of 3D Educational Technologies of UFAC, under no. 23107.007273/2017-49 (CEUA/UFAC). A canine skeleton (hip bone, femurs and patellae) was used without anatomical deformities compatible with DCF (pelvis, femurs and patella), which were scanned in order to obtain the files of the base model. In these files the deformations representing the different degrees of CHD were performed. Subsequently, the 3D AMCHD files were printed, mounted and X-rayed. The 3D AMCHD represented the bone deformations of the different degrees of CHD. In the radiographs of the 3D AMCHD it was possible to observe and determine each of the bones that constituted the hip joints. This allowed to reproduce the correct positioning to represent the CHD diagnosis and establish the precise points to determine the Norberg angle. In this way, it was evidenced that the 3D AMCHD can be a possible tool to be used in the Teaching of Veterinary Medicine.(AU)

A displasia coxofemoral canina (DCF) é uma condição patológica articular de grande prevalência. Nesse sentido, a radiografia torna-se um método de diagnóstico importante para determinar a presença e a gravidade da doença. O objetivo do presente trabalho foi criar modelos 3D e suas respectivas radiografias representando a DCF (MADCF 3D). A pesquisa foi realizada no Laboratório de Tecnologias Educacionais 3D da UFAC, sob o nº. 23107.007273/2017-49 (Ceua/Ufac). Foram utilizados esqueletos caninos (pelve, fêmures e patelas) sem deformidades anatômicas compatíveis com a DCF, os quais foram digitalizados a fim de se obterem os arquivos do modelo base. Nesses arquivos foram realizadas as deformações que representavam os diferentes graus da DCF. Posteriormente, os arquivos dos MADCF 3D foram impressos, montados e radiografados. Os MADCF 3D representaram as deformações ósseas dos diferentes graus da DCF. Nas radiografias dos MADCF 3D, foi possível observar e determinar cada um dos ossos que constituíam as articulações coxofemorais. Isso permitiu reproduzir o posicionamento correto para representação do diagnóstico DCF e estabelecer os pontos precisos para determinar o ângulo de Norberg. Dessa forma, evidenciou-se que os MADCF 3D podem ser uma possível ferramenta a ser empregada no ensino de medicina veterinária.(AU)

3D printing of canine hip dysplasia: anatomic models and radiographs / Impressão 3D da displasia coxofemoral canina: modelos anatômicos e radiografias

Canine Hip Dysplasia (CHD) is a highly prevalent articular pathological condition. In this sense, radiography becomes an important diagnostic method to determine the presence and severity of the disease. The objective was to create 3D models and their respective radiographs representing the CHD (3D AMCHD). The research was carried out in the Laboratory of 3D Educational Technologies of UFAC, under no. 23107.007273/2017-49 (CEUA/UFAC). A canine skeleton (hip bone, femurs and patellae) was used without anatomical deformities compatible with DCF (pelvis, femurs and patella), which were scanned in order to obtain the files of the base model. In these files the deformations representing the different degrees of CHD were performed. Subsequently, the 3D AMCHD files were printed, mounted and X-rayed. The 3D AMCHD represented the bone deformations of the different degrees of CHD. In the radiographs of the 3D AMCHD it was possible to observe and determine each of the bones that constituted the hip joints. This allowed to reproduce the correct positioning to represent the CHD diagnosis and establish the precise points to determine the Norberg angle. In this way, it was evidenced that the 3D AMCHD can be a possible tool to be used in the Teaching of Veterinary Medicine.(AU)

A displasia coxofemoral canina (DCF) é uma condição patológica articular de grande prevalência. Nesse sentido, a radiografia torna-se um método de diagnóstico importante para determinar a presença e a gravidade da doença. O objetivo do presente trabalho foi criar modelos 3D e suas respectivas radiografias representando a DCF (MADCF 3D). A pesquisa foi realizada no Laboratório de Tecnologias Educacionais 3D da UFAC, sob o nº. 23107.007273/2017-49 (Ceua/Ufac). Foram utilizados esqueletos caninos (pelve, fêmures e patelas) sem deformidades anatômicas compatíveis com a DCF, os quais foram digitalizados a fim de se obterem os arquivos do modelo base. Nesses arquivos foram realizadas as deformações que representavam os diferentes graus da DCF. Posteriormente, os arquivos dos MADCF 3D foram impressos, montados e radiografados. Os MADCF 3D representaram as deformações ósseas dos diferentes graus da DCF. Nas radiografias dos MADCF 3D, foi possível observar e determinar cada um dos ossos que constituíam as articulações coxofemorais. Isso permitiu reproduzir o posicionamento correto para representação do diagnóstico DCF e estabelecer os pontos precisos para determinar o ângulo de Norberg. Dessa forma, evidenciou-se que os MADCF 3D podem ser uma possível ferramenta a ser empregada no ensino de medicina veterinária.(AU)

3D printing as a diagnostic tool for congenital malformation in a brachycephalic dog / Impressão 3D como ferramenta de diagnóstico para malformação congênita em cão braquicefálico

ABSTRACT: Congenital anomalies are hereditary or acquired, and their location and intensity are determining factors for the survival of animals. Some cases are rare, often unidentified, poorly reported and of unknown etiology. This paper reports a congenital malformation in a French bulldog, demonstrating the importance of accurate diagnosis for surgical decisions. The use of new technologies such as computed tomography and rapid prototyping enables the analysis of morphofunctional changes, resulting in excellent results for clinical cases in which it is difficult to identify and scale the anatomical deformities. Through this feature, it is possible to accurately recreate anatomical structures of interest, enabling greater assertiveness in deciding the treatment to be established, whether surgical or not. Castration of animals that survive this condition due to hereditary etiology is recommended.

RESUMO: Anomalias congênitas possuem caráter hereditário ou adquirido, sendo que sua localização e intensidade são fatores determinantes para a sobrevivência do animal. Algumas são raras, muitas vezes não identificadas, pouco relatadas e com etiologia desconhecida. O presente trabalho registra um caso de malformação congênita em um bulldog francês, demonstrando a importância do diagnóstico preciso para a decisão cirúrgica. A utilização de novas tecnologias como tomografia computadorizada e prototipagem rápida possibilitam a análise de alterações morfofuncionais, tendo ótimo resultado para casos clínicos em que há dificuldade em identificar e dimensionar deformidades anatômicas. Através desse recurso é possível recriar com precisão estruturas anatômicas de interesse, possibilitando maior assertiva na decisão do tratamento a ser estabelecido, sendo ele cirúrgico ou não. É recomendada a castração dos animais que sobreviveram a essa condição, devido a etiologia hereditária.

Otobone ®: Three-dimensional printed Temporal Bone Biomodel for Simulation of Surgical Procedures

Introduction: The anatomy of the temporal bone is complex due to the large number of structures and functions grouped in this small bone space, which do not exist in any other region in the human body. With the difficulty of obtaining anatomical parts and the increasing number of ear, nose and throat (ENT) doctors, there was a need to create alternatives as real as possible for training otologic surgeons. Objective: Developing a technique to produce temporal bone models that allow them to maintain the external and internal anatomical features faithful to the natural bone. Methods: For this study, we used a computed tomography (CT) scan of the temporal bones of a 30-year-old male patient, with no structural morphological changes or any other pathology detected in the examination, which was later sent to a 3D printer in order to produce a temporal bone biomodel. Results: After dissection, the lead author evaluated the plasticity of the part and its similarity in drilling a natural bone as grade "4" on a scale of 0 to 5, in which 5 is the closest to the natural bone and 0 the farthest from the natural bone. All structures proposed in the method were found with the proposed color. Conclusion: It is concluded that it is feasible to use biomodels in surgical training of specialist doctors. After dissection of the bone biomodel, it was possible to find the anatomical structures proposed, and to reproduce the surgical approaches most used in surgical practice and training implants (AU)

Otobone ® : Three-dimensional printed Temporal Bone Biomodel for Simulation of Surgical Procedures.

Introduction The anatomy of the temporal bone is complex due to the large number of structures and functions grouped in this small bone space, which do not exist in any other region in the human body. With the difficulty of obtaining anatomical parts and the increasing number of ear, nose and throat (ENT) doctors, there was a need to create alternatives as real as possible for training otologic surgeons. Objective Developing a technique to produce temporal bone models that allow them to maintain the external and internal anatomical features faithful to the natural bone. Methods For this study, we used a computed tomography (CT) scan of the temporal bones of a 30-year-old male patient, with no structural morphological changes or any other pathology detected in the examination, which was later sent to a 3D printer in order to produce a temporal bone biomodel. Results After dissection, the lead author evaluated the plasticity of the part and its similarity in drilling a natural bone as grade "4" on a scale of 0 to 5, in which 5 is the closest to the natural bone and 0 the farthest from the natural bone. All structures proposed in the method were found with the proposed color. Conclusion It is concluded that it is feasible to use biomodels in surgical training of specialist doctors. After dissection of the bone biomodel, it was possible to find the anatomical structures proposed, and to reproduce the surgical approaches most used in surgical practice and training implants.

Skull reconstruction after resection of bone tumors in a single surgical time by the association of the techniques of rapid prototyping and surgical navigation.

PURPOSE: Presentation of a new cranioplasty technique employing a combination of two technologies: rapid prototyping and surgical navigation. This technique allows the reconstruction of the skull cap after the resection of a bone tumor in a single surgical time. METHODS: The neurosurgeon plans the craniotomy previously on the EximiusMed software, compatible with the Eximius Surgical Navigator, both from the company Artis Tecnologia (Brazil). The navigator imports the planning and guides the surgeon during the craniotomy. The simulation of the bone fault allows the virtual reconstruction of the skull cap and the production of a personalized modelling mold using the Magics-Materialise (Belgium)-software. The mold and a replica of the bone fault are made by rapid prototyping by the company Artis Tecnologia (Brazil) and shipped under sterile conditions to the surgical center. The PMMA prosthesis is produced during the surgical act with the help of a hand press. RESULTS: The total time necessary for the planning and production of the modelling mold is four days. The precision of the mold is submillimetric and accurately reproduces the virtual reconstruction of the prosthesis. The production of the prosthesis during surgery takes until twenty minutes depending on the type of PMMA used. The modelling mold avoids contraction and dissipates the heat generated by the material's exothermic reaction in the polymerization phase. The craniectomy is performed with precision over the drawing made with the help of the Eximius Surgical Navigator, according to the planned measurements. The replica of the bone fault serves to evaluate the adaptation of the prosthesis as a support for the perforations and the placement of screws and fixation plates, as per the surgeon's discretion. CONCLUSIONS: This technique allows the adequate oncologic treatment associated with a satisfactory aesthetic result, with precision, in a single surgical time, reducing time and costs.

A digital approach for design and fabrication by rapid prototyping of orthosis for developmental dysplasia of the hip

Abstract Introduction Immobilization in a hip spica cast is required in surgical and nonsurgical treatments for children aged three months to four years diagnosed with developmental dysplasia of the hip. Skin complications are associated with the use of the spica cast in 30% of the cases. This research explores the use of photogrammetry and rapid prototyping for the production of a lighter, shower friendly and hygienic hip orthosis that could replace the hip spica cast. Methods Digitalized data of a plastic dool was used for design and fabrication of a customised hip orthosis following four steps: 1) Digitalization of the external anatomical structure by photogrammetry using a smartphone and open source software; 2) Idealization and 3D modeling of the hip orthosis; 3) Rapid prototyping of a low cost orthosis in polymer polylact acid; 4) Evaluation tests. Results Photogrammetry provided a good 3D reconstruction of the dool's hip and legs. The manufacture method to produce the hip orthosis was accurate in fitting the hip orthosis to the contours of the doll. The orthosis could be easily placed on the doll ensuring mechanical strength to immobilize the region of the hip. Conclusion A new approach and the feasibility of both techniques for hip orthosis fabrication were described. It represents an exciting advance for the development of hip orthosis that could be used in orthopedics. To test the effectiveness of this orthosis for developmental dysplasia of the hip treatment in newborns, material and mechanical tests, design optimization and physical tests with patients should be carried.

Use of prototyping in preoperative planning for patients with head and neck tumors.

BACKGROUND: Prototyping technologies for reconstructions consist of obtaining a 3-dimensional model of the object of interest. Solid models are constructed by the deposition of materials in successive layers. The purpose of this study was to perform a double-blind, randomized, prospective study to evaluate the efficacy of prototype use in head and neck surgeries. METHODS: Thirty-seven cases were randomized into prototype and nonprototype groups. The following factors were recorded: the time of plate and locking screw apposition, flap size, time for reconstruction, and an aesthetic evaluation. RESULTS: The prototype group exhibited a reduced surgical time (43.7 minutes vs 127.7 minutes, respectively; p = .001), a tendency to reduce the size of the bone flap taken for reconstruction, and better aesthetic results than the group that was not prototyped. CONCLUSION: The use of prototyping demonstrated a trend toward a reduced surgical time, smaller bone flaps, and better aesthetic results.

Microstructure and mechanical behavior of porous Ti-6Al-4V parts obtained by selective laser melting.

Rapid prototyping allows titanium porous parts with mechanical properties close to that of bone tissue to be obtained. In this article, porous parts of the Ti-6Al-4V alloy with three levels of porosity were obtained by selective laser melting with two different energy inputs. Thermal treatments were performed to determine the influence of the microstructure on the mechanical properties. The porous parts were characterized by both optical and scanning electron microscopy. The effective modulus, yield and ultimate compressive strength were determined by compressive tests. The martensitic α' microstructure was observed in all of the as-processed parts. The struts resulting from the processing conditions investigated were thinner than those defined by CAD models, and consequently, larger pores and a higher experimental porosity were achieved. The use of the high-energy input parameters produced parts with higher oxygen and nitrogen content, their struts that were even thinner and contained a homogeneous porosity distribution. Greater mechanical properties for a given relative density were obtained using the high-energy input parameters. The as-quenched martensitic parts showed yield and ultimate compressive strengths similar to the as-processed parts, and these were greater than those observed for the fully annealed samples that had the lamellar microstructure of the equilibrium α+ß phases. The effective modulus was not significantly influenced by the thermal treatments. A comparison between these results and those of porous parts with similar geometry obtained by selective electron beam melting shows that the use of a laser allows parts with higher mechanical properties for a given relative density to be obtained.

Implante craneano individual de gran volumen en polimetilmetacrilato demetilo a partir de un prototipo rápido: reporte de un caso / Development of individual cranial implant large in PMMA from a rapid prototype: a case report

Se realizó la reconstrucción aloplástica de un gran defecto de cráneo de etiología traumática, en una paciente de sexo femenino de 24 años de edad. Debido a la particular complejidad del caso, se utilizó una técnica para la construcción de la prótesis que involucró el procesamiento imagenológico 3D, asistido por ordenador y la posterior confección de un prototipo rápido. Sobre este prototipo se realizó la planifi cación y reconstrucción protésica, obteniendo un implante craneano interno de gran volumen, con absoluta exactitud. La inter-relación de distintas especialidades del área de la salud, fue imprescindible para la solución de este caso, posicionando a la disciplina de la Prótesis Buco Maxilo Facial denro de la más alta medicina rehabilitadora integral. El procedimiento empleado resultó adecuado, para reconstruir defectos internos complejos de restitución ósea, en comparación a los métodos empleados hasta el momento.

Alloplastic reconstruction was performed of a large skull defect of traumatic etiology in a female patient 24 years of age. Due to the particular complexity of the case a technique for denture construction had to be used, involving 3D imaging processing, computer aided and the subsequent production of a rapid prototype. This enabled the planning and prosthetic reconstruction on a rapid prototype, obtaining a large internal cranial implant volume, with absolute accuracy. The inter-relationship of different specialties in the area of health was essential to resolving this case, positioning the discipline of Maxillofacial Prosthesis within the highest integral medicine. This procedure was the adequate to reconstruct complex internal defects of bone restitution, compared to the methods used so far.

Projeto, fabricação e avaliação de implantes craniofaciais personalizados: proposta de utilização de materiais combinados / Design, production and evaluation of customized craniofacial implants: an approach on the use of different materials

Um material adequado para a reconstrução óssea craniofacial deve ser simples de implantar, possuir forma adequada, resistência à fratura e à deformação similares ao osso original, ser eventualmente substituído por osso natural, ser largamente disponível e não possuir um custo muito elevado. Baseado no fato de que um material com todas estas características ainda não está disponível atualmente, torna-se importante buscar novos materiais, novas composições e novas conformações. Diferentes biomateriais são utilizados atualmente para cirurgias de reconstrução craniofacial, cada um apresentando suas vantagens e limitações. Entre eles destacam-se o titânio, o polimetilmetacrilato e os cimentos de fosfato de cálcio. O titânio apresenta difícil conformação; o polimetilmetacrilato polimeriza-se por meio de uma reação exotérmica, podendo causar necrose de tecidos adjacentes ao implante; o cimento de fosfato de cálcio, por sua vez apresenta certa fragilidade, característica de alguns materiais cerâmicos. Neste sentido, este estudo examinou diferentes materiais utilizados para reconstrução craniofacial e suas propriedades mecânicas quando submetidos a ensaios de flexão, como o polimetilmetacrilato, o cimento de fosfato de cálcio e o cimento de fosfato de cálcio reforçado com titânio. Foi verificada a melhoria de propriedades mecânicas do cimento de fosfato de cálcio quando reforçado com malha de titânio. Além disso, este estudo apresenta uma técnica para o projeto e fabricação de implantes craniofaciais personalizados utilizando cimento de fosfato de cálcio reforçado com titânio, validada através de quatro casos de indicação cirúrgica de reconstrução craniofacial.

A material suitable for craniofacial reconstruction must be easy to implant, have the appropriate shape, have the strength and deformation similar to the original bone, be eventually substituted for natural bone, be widely available and present affordable costs. As such as material, with all theses characteristics is still not available, it is important to search for new materials, new compositions and new design. Different biomaterials are used nowadays for craniofacial reconstruction surgeries, each one presenting its advantages and limitations. Among these materials are the titanium, the poli(methilmetacrilate) and the calcium phosphate cements. Titanium presents hard conformation; poli(methilmetacrilate)’s polymerization reaction is exothermic, which may cause necrosis of the adjacent tissues; calcium phosphate cement is brittle, an usual characteristic of ceramic materials. In this way, this study evaluated different materials used for craniofacial reconstruction and its mechanical properties when submitted to bending test, such as poli(methilmetacrilate), calcium phosphate cement and calcium phosphate cement reinforced with titanium. It was verified the improvement in the mechanical properties of the calcium phosphate cement when reinforced with titanium mesh. In addition, this study presents a method for design and manufacturing of customized craniofacial implants using calcium phosphate cement reinforced with titanium mesh, validated through four cases of craniofacial reconstruction surgery indication.

Acquisition and manipulation of computed tomography images of the maxillofacial region for biomedical prototyping / Aquisição e manipulação de imagens por tomografia computadorizada da região maxilofacial visando à obtenção de protótipos biomédicos

O processo de construção de protótipos biomédicos surgiu da união das tecnologias de prototipagem rápida e do diagnóstico por imagens. No entanto, este processo é complexo, em função da necessária interação entre as ciências biomédicas e a engenharia. Para que bons resultados sejam obtidos, especial atenção deve ser dispensada à aquisição das imagens por tomografia computadorizada e à manipulação dessas imagens em softwares específicos. Este artigo apresenta a experiência multidisciplinar de um grupo de pesquisadores com a aquisição e a manipulação de imagens por tomografia computadorizada do complexo maxilofacial, visando à construção de protótipos biomédicos com finalidade cirúrgica.

Biomedical prototyping has resulted from a merger of rapid prototyping and imaging diagnosis technologies. However, this process is complex, considering the necessity of interaction between biomedical sciences and engineering. Good results are highly dependent on the acquisition of computed tomography images and their subsequent manipulation by means of specific softwares. The present study describes the experience of a multidisciplinary group of researchers in the acquisition and manipulation of computed tomography images of the maxillofacial region aiming at biomedical prototyping for surgical purposes.