Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-17T13:55:19Z No. of bitstreams: 1 thaiscamargobittencourt.pdf: 3474280 bytes, checksum: d976f27ac38bb3957228bd3568883227 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T16:25:44Z (GMT) No. of bitstreams: 1 thaiscamargobittencourt.pdf: 3474280 bytes, checksum: d976f27ac38bb3957228bd3568883227 (MD5) / Made available in DSpace on 2017-05-17T16:25:44Z (GMT). No. of bitstreams: 1 thaiscamargobittencourt.pdf: 3474280 bytes, checksum: d976f27ac38bb3957228bd3568883227 (MD5) Previous issue date: 2012-03-30 / Neste estudo randomizado e prospectivo objetivou-se avaliar, clínica e radiograficamente, tecidos peri-implantares e comparar próteses cerâmicas com metalocerâmicas. Dos sessenta implantes instalados em região estética, dois não osseointegraram reduzindo a amostra à cinquenta e oito implantes. Na reabilitação utilizou-se pilares e copings convencionais de titânio (próteses metalocerâmicas) e pilares pré-fabricados em zircônia com copings do mesmo material, personalizados pelo sistema CAD/CAM (próteses cerâmicas). Toda a amostra foi acompanhada por radiografia digital nos diferentes tempos (imediatamente, após três e cinco meses de função). Parâmetros específicos foram adotados para avaliação dos tecidos peri-implantares e suas coroas. Em relação à estética dos tecidos, não houve significância entre as diferentes reabilitações. Foi verificada diferença estatisticamente significante no parâmetro WES “total” com melhoria estética observada nas coroas cerâmicas. Nos tecidos peri-implantares destas próteses foi possível observar uma constância em todas as variáveis de sondagem e uma tendência a menor acúmulo de placa. Desta forma, pôde-se concluir que o acompanhamento de cinco meses revelou resultados estéticos agradáveis e tecidos peri-implantares saudáveis. Pilares de ZrO2 oferecem estabilidade suficiente para suportar próteses unitárias sobre implante em regiões estéticas. Próteses sobre pilares pré-fabricados de zircônia e copings CAD/CAM, do mesmo material, apresentaram melhores resultados estéticos conforme parâmetros pré-estabelecidos (WES). As radiografias digitais por análise subjetiva visual demonstraram uma crista óssea estável ao redor da plataforma dos implantes. / This prospective randomized study aimed to evaluate clinically and radiologically, peri-implant tissues and comparing metal-ceramic prostheses on pillars and conventional titanium copings with ceramic prostheses on prefabricated pillars of zirconia with copings the same material, custom by CAD/CAM system. Sixty implants were installed in aesthetic regions, in 35 patients. The entire sample, only two implants were lost. The implanted sites were divided into two groups receiving metal-ceramic and ceramic crowns. The entire sample was follow by digital radiography at different times (immediately, after three and five months function). To evaluate the criteria adopted if specific parameters for assessing peri-implant tissues and their crowns according Buser, Weber and Lang (1990), Mombelli et al. (1987), Belser et al. (2009), Blanes et al. (2007) and the Likert Scale. The aesthetics of the tissues was best seen according to PES "total" for the three-month evaluation, and to ZrO2 6.96 (± 1.64) and to Ti 6.55 (± 1.99). Statistically significant difference was observed in the WES "total" between the crowns, and 8.36 (± 1.22) for ZrO2 and 6.96 (± 1.52) for the Ti. In prosthesis on pillars of ZrO2 was possible to observe constancy in all the pump variables of Blanes et al. (2007). Thus, we concluded that the monitoring of five-months revealed pleasing esthetic results and peri-implant tissues healthy. Pillars of ZrO2 provide sufficient stability to support single tooth implant prostheses for aesthetic regions, considered up to the 2nd premolar. Despite high survival rates of both groups, prostheses on prefabricated pillars of ZrO2 and copings CAD/CAM, the same material, showed better aesthetic results as pre-established parameters for assessment reproducible of soft tissue and her crown (PES/WES). Digital radiographs either by subtraction or by subjective visual analysis showed a stable bone crest around the implant platform.

Orientador: João Maurício Rosário / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-20T17:16:06Z (GMT). No. of bitstreams: 1 GonzalezCardozo_CarlosAurelio_M.pdf: 3291710 bytes, checksum: 44b69cb0622c9a8dd792e7d9b3e4cee9 (MD5) Previous issue date: 2012 / Resumo: A Manufatura Digital integra o projeto do produto ao planejamento dos processos de manufatura e de suporte ao produto. Produtos, processos e recursos são modelados a partir de dados reais, em uma fábrica virtual. O funcionamento desta fábrica virtual é testado até sua validação e os resultados são aplicados na fábrica real. É uma importante alternativa com potencial para transformar os negócios, tornando-os mais competitivos, graças aos diversos benefícios conseguidos com a Manufatura Digital, tais como redução dos ciclos de desenvolvimento do produto e dos custos de manufatura, aceleração de resposta ao mercado, aumento da qualidade do produto, melhoras na disseminação do conhecimento do produto. O objetivo deste estudo é descrever a aplicação da Manufatura Digital no Contexto de Engenharia Reversa através de um estudo de caso de um Projeto Colaborativo Internacional que resultou no Protótipo Virtual de um avião Blériot XI e fabricação de uma réplica deste avião, com o objetivo de validar a implantação da Manufatura Digital em um ambiente educacional / Abstract: The Digital Manufacturing integrates product design to manufacturing process planning and product support. Products, processes and resources are modeled from real data in a virtual factory. The operation of the virtual factory is tested to its validation and the results are applied to actual plant. It is an important alternative with the potential to transform businesses, making them more competitive, thanks to the many benefits achieved through Digital Manufacturing, such as reducing product development cycles and manufacturing cost, rapid response to market, increased product quality improvements in the dissemination of product knowledge. The aim of this study is to describe the application of Digital Manufacturing in the Context of Reverse Engineering through a case study an International Collaborative Project which resulted in the Virtual Prototype of an airplane Blériot XI and manufacture of a replica of this plane, with the aim of validating the deployment of Digital Manufacturing in an educational environment / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

The present work presents the development of a methodology for transforming conventional roll benders of industrial tubes and plates into an equipment with a programmable automatic system for bending parts with fixed and/or changeable rays. A conceptual mechanical project (without details) is presented and computational resources were implemented for recognition of drawings defined in a system of computer aided design with the objective of automatically generating the task-program, being capable of making the conformation of the projected part. This way, the requirement of programmable operation is satisfied and the equipment will work according to principles of numerical command machines. Besides that, the proposal considers the necessary adjustment in the machine operational parameters because of the material springback through the image processing extracted from a photo of the conformed part. Thus, the ray executed in the part is recognized and makes it possible to compare it with the projected ray. According to this study, the system was implemented as an applicative of CAD system for the technique viability analysis and was concluded to be viable, since the programming methodology was implemented successfully and the results were satisfactory, the user can draw a part in a CAD system and a program CNC is generated for the execution of the part. Other related and important aspects for the development of the methodology are discussed, such as: CNC programming, image processing, CAD programming systems and the process of mechanical forming to bend tubes or plates. / O presente trabalho apresenta o desenvolvimento de uma metodologia para transformar calandras de tubos e chapas convencionais em equipamentos com sistema automático programável para execução de peças com raios fixos e/ou variáveis. É apresentado um projeto mecânico conceitual (sem detalhamento) e são implementados recursos computacionais para reconhecimento de desenhos definidos em sistema de projeto auxiliado por computador com o objetivo de gerar automaticamente o programa-tarefa capaz de executar a conformação da peça projetada. Desta maneira, o requisito de operação programável é satisfeito fazendo com que o equipamento trabalhe segundo os princípios de máquinas CNC. A proposta considera ainda o ajuste necessário nos parâmetros de operação da máquina devido a recuperação elástica do material através do processamento de uma imagem extraída de uma foto da peça conformada. Desta forma, o raio executado na peça é reconhecido e torna-se possível compará-lo com o raio projetado. Conforme demonstra o estudo, para análise da viabilidade técnica da proposta, o sistema foi implementado na forma de aplicativo de sistema CAD e conclui-se ser viável, já que a metodologia de programação foi implementada com sucesso e gerou resultados satisfatórios, onde o usuário desenha uma peça em sistema CAD e um programa CNC para a execução da peça é gerado. Outros aspectos relativos e importantes para o desenvolvimento da metodologia são discutidos, tais como: programação CNC, processamento de imagens, programação em sistemas CAD e processo de conformação mecânica para curvar tubos ou chapas.

Background Ablative tumor surgery often results in continuity defects of the mandible. When an immediate reconstruction using autologous bone grafts is not possible the bridging of the defects with a variety of bridging plates might be achieved. However, those bridging plates have the risk of plate fractures or exposure. Customized titanium implants manufactured using CAD/CAM and the LaserCUSING® technique might be an alternative. Methods In the present study, computed tomographies (CT) of porcine cadaver mandibles were generated and transferred into DICOM data. Following, different continuity defects were surgically created in the mandibles. Based on the DICOM data customized titanium implants were manufactured using CAD/CAM procedures and the LaserCUSING® technique. The implants were fixed to the remaining stumps with screws. Subsequently, the accuracy of the reconstructed mandibles was tested using plaster casts. Results The workflow from the CT to the application of the customized implants was proved to be practicable. Furthermore, a stable fixation of the customized implant to the remaining stumps could be achieved. The control of the accuracy showed no frictions or obstacles. Conclusion The customized titanium implant seems to be a promising approach to bridge continuity defects of the mandible whenever an immediate reconstruction with autologous bone is not possible.

Background Ablative tumor surgery often results in continuity defects of the mandible. When an immediate reconstruction using autologous bone grafts is not possible the bridging of the defects with a variety of bridging plates might be achieved. However, those bridging plates have the risk of plate fractures or exposure. Customized titanium implants manufactured using CAD/CAM and the LaserCUSING® technique might be an alternative. Methods In the present study, computed tomographies (CT) of porcine cadaver mandibles were generated and transferred into DICOM data. Following, different continuity defects were surgically created in the mandibles. Based on the DICOM data customized titanium implants were manufactured using CAD/CAM procedures and the LaserCUSING® technique. The implants were fixed to the remaining stumps with screws. Subsequently, the accuracy of the reconstructed mandibles was tested using plaster casts. Results The workflow from the CT to the application of the customized implants was proved to be practicable. Furthermore, a stable fixation of the customized implant to the remaining stumps could be achieved. The control of the accuracy showed no frictions or obstacles. Conclusion The customized titanium implant seems to be a promising approach to bridge continuity defects of the mandible whenever an immediate reconstruction with autologous bone is not possible.

This master's thesis deals with the manufacturing of a hunting crossbow prototype. The first part summarizes the history of crossbows, their historical development and usage. The following chapter contains theoretical knowladge about the technological methods that are used in the production. This is followed by a designing of the prototype, creating a technological process and final production. Final part of this thesis evaluates individual parts of the production and the final prototype.

The goal of this diploma thesis is to describe the proposal for integrating production control system in the growing manufacturing company with custom-made production. Initially the research of applicable methods and operations suitable for the company management will be done. Next step will be to apply these procedures in the company and eventually to provide a range of adjustments. As a result, not only an optimal production control system eliminating possible mistakes stemming from the insufficient control management is implemented, but also the company is prepared for further profitable growth.

Der verschärfte Wettbewerb auf den globalisierten Märkten, wachsender Termindruck sowie steigende Qualitätsanforderungen machen das betriebsspezifische Know-how bei der Anfertigung von Betriebsmitteln zum entscheidenden Wettbewerbsfaktor. Durch die in Werkzeug- und Formenbaubetrieben traditionell anzutreffende Werkstattorganisation wird dieses Wissen individuell durch die Erfahrungen der Facharbeiter gehalten, woraus eine geringe Transparenz der Fertigungsabläufe sowie ein hoher Anteil manueller Tätigkeiten bei der Arbeitsplanung resultiert. Zur Standardisierung und Automatisierung von Fertigungsabläufen ist folglich die Akquisition internen Erfahrungswissens erforderlich, die sowohl bei organisationalen als auch IT-orientierten Wissensmanagement-Ansätzen als hochaufwändig gilt. Anhand vorhandener globaler Modelle wurde in dieser Arbeit ein Ansatz entwickelt, der mit Hilfe maschineller Lernverfahren eine automatisierte Wissensakquisition ermöglicht. Auf Grundlage der abgeleiteten Wissensbedarfe „Werkzeuge“ und „Schnittwerte“ und den besonderen Randbedingungen bei der NC-Programmierung mit Hilfe eines grafisch interaktiven CAM-Systems wurden Verfahren konzipiert, die eine automatisierte Akquisition, Standardisierung und regelbasierte Repräsentation von Erfahrungswissen auf Basis einer großen Anzahl an Fallbeispielen ermöglicht. Die entworfenen Lernverfahren wurden prototypisch implementiert und ihre Funktionsfähigkeit anhand einer Datenbasis mit 24.000 realen Fallbeispielen (1 Fallbeispiel entspricht 1 Operation/NC-Programm) nachgewiesen. Die Plausibilität des akquirierten Wissens sowie seine automatisierte Verarbeitung mit Hilfe moderner kommerzieller CAM-Systeme wurde abschließend durch die NC-Programmierung eines Beispielwerkstücks unter Verwendung einer kommerziellen CAM-Software demonstriert.:1. Einleitung 15 2. Stand der Technik 17 2.1. Allgemeines Umfeld 17 2.1.1. Produktspektrum 17 2.1.2. Technologie 18 2.2. Rechnergestützte Arbeitsplanung im Werkzeug- und Formenbau 25 2.2.1. Grundlagen und Begriffsklärung 25 2.2.2. NC-Verfahrenskette 28 2.2.3. CAPP-Systeme 31 2.2.4. CAM-Systeme 32 2.2.5. Organisation 40 2.3. Herausforderung Wissensnutzung (Zwischenfazit) 44 2.4. Rechnergestützte Nutzung von Erfahrungswissen 45 2.4.1. Grundlagen und Begriffsabgrenzung 45 2.4.2. Wissensmanagement und Wissensbasierte Systeme 47 2.4.3. Wissensrepräsentation 49 2.4.4. Wissensakquisition 53 2.5. Automatisierte Wissensverarbeitung in der Arbeitsplanung 59 3. Fazit und Lösungsansatz 63 4. Datenbeschaffung 69 4.1. Konvertierung des Datenbestandes 69 4.2. Aufbereitung des Datenbestandes 73 4.2.1. Identifizierung nicht aussagefähiger Attribute 73 4.2.2. Identifizierung nicht aussagefähiger Datenobjekte 74 4.2.3. Syntaktische und semantische Inkonsistenzen 74 4.2.4. Fehlende Werte 75 4.2.5. Fehlerhafte Werte 76 4.3. Fazit 76 5. Analyse der Wissensdomäne 77 5.1. Vorbetrachtungen 77 5.2. Informationsstruktur: Das CAD/CAM-Informationsmodell 80 5.2.1. Beschreibung des Werkstücks 81 5.2.2. Beschreibung der Bearbeitungsprozesses 82 5.3. Informationsgenerierung: CAD/CAM- gestützte NC-Programmierung 84 5.3.1. Geometrievorbereitung 85 5.3.2. Bestimmung des Operationsplans 86 5.3.3. Berechnung, Simulation und Bereitstellung 98 5.4. Ableitung und Formalisierung der Wissensziele 99 5.5. Zusammenfassung und weitere Vorgehensweise 100 6. Automatisierte Wissensakquisition 103 6.1. Lernen von sequenziellen Beziehungen 103 6.1.1. Analyseverfahren 103 6.1.2. Modellierung von Markov-Ketten 103 6.2. Lernen von ableitenden Beziehungen 106 6.2.1. Analyseverfahren 107 6.2.2. Induktion von Entscheidungsbäumen 111 6.3. Evaluation 120 6.4. Applikation 123 6.5. Standardisierung 124 6.5.1. Attribute mit diskretem Wertebereich 125 6.5.2. Attribute mit kontinuierlichem Wertebereich 127 6.6. Fazit 129 7. Ergebnisse 131 7.1. Datenselektion 131 7.2. Untersuchungsfeld 1: Regeln für Werkzeugfolgen 133 7.2.1. Transformation 134 7.2.2. Modellbildung 138 7.2.3. Regel-Anwendung 143 7.3. Untersuchungsfeld 2: Regeln für Werkzeuge 145 7.3.1. Transformation 145 7.3.2. Modellbildung (univariater Entscheidungsbaum) 148 7.3.3. Modellbildung (multivariater Entscheidungsbaum) 150 7.3.4. Standardisierung 154 7.3.5. Regel-Anwendung 161 7.4. Untersuchungsfeld 3: Regeln für Schnittwerte 162 7.4.1. Transformation 162 7.4.2. Modellbildung 162 7.4.3. Standardisierung 167 7.4.4. Regel-Anwendung 169 7.5. Fazit 170 8. Prototypische Realisierung 175 8.1. Wissensakquisitionsmodul 176 8.1.1. Datenkonverter 176 8.1.2. Lernprozessor 178 8.2. Wissensspeicherung und -verarbeitung im CAD/CAM-System 181 8.2.1. Automatische Verarbeitung von Anwendungswissen 181 8.2.2. Manuelle Verarbeitung von Anwendungswissen 183 8.2.3. Wissensspeicherung und -verarbeitung in hyperMILL® 185 8.3. Beispielhafte Anwendung 189 8.3.1. Globale Eingangsinformationen 189 8.3.2. Rechnergestützte wissensbasierte NC-Programmierung 190 9. Zusammenfassung und Ausblick 197 10. Anhang 201 Anhang A 201 Anhang B 202 Abkürzungsverzeichnis 203 Literaturverzeichnis 207 / The intensive competitive environment on globalized markets, the growing deadline pressure caused by shortened product life cycles as well as increasing quality requirements emphasize the company-specific know-how as a decisive competitive factor for toolmakers. Due to the traditional shop floor organization within toolmaking companies, this knowledge is individually held by experiences of the single skilled worker which a low transparency of manufacturing processes as well as a high degree of manual activities at the operation planning process results from. In that form of representation the existing manufacturing knowledge of the company can not be, independent of individual people, integrated in the value-adding process and hence can not be used consequently. Therefore the standardization and automation of manufacturing processes requires the acquisition of internal experience-based knowledge, what is deemed to be a complex task in organizational as well as in IT-based approaches. Based on existing global models the present work develops an approach that enables an automated acquisition of knowledge using methods of data mining based on an amount of real sample data. For that purpose, methods for the automatic extraction, preparation and structured storage of sample data sourced from a commercial CAM system were developed and prototypically implemented. Based on the specified knowledge demands, „milling tools“ and „cutting data“ as well as the special environment of the shop-floor oriented NC programming by using a graphically interactive CAM system, adequate learning methods were conceived that enable an automated acquisition, standardization and rule based representation of experiential knowledge. The conceived methods were prototypically implemented and their functional capability was verified on the basis of the mentioned amount of real sample data. The plausibility of the acquired knowledge as well as its automated processing capability within modern CAM systems was finally proved by the NC programming of a sample part using the CAM software hyperMILL®.:1. Einleitung 15 2. Stand der Technik 17 2.1. Allgemeines Umfeld 17 2.1.1. Produktspektrum 17 2.1.2. Technologie 18 2.2. Rechnergestützte Arbeitsplanung im Werkzeug- und Formenbau 25 2.2.1. Grundlagen und Begriffsklärung 25 2.2.2. NC-Verfahrenskette 28 2.2.3. CAPP-Systeme 31 2.2.4. CAM-Systeme 32 2.2.5. Organisation 40 2.3. Herausforderung Wissensnutzung (Zwischenfazit) 44 2.4. Rechnergestützte Nutzung von Erfahrungswissen 45 2.4.1. Grundlagen und Begriffsabgrenzung 45 2.4.2. Wissensmanagement und Wissensbasierte Systeme 47 2.4.3. Wissensrepräsentation 49 2.4.4. Wissensakquisition 53 2.5. Automatisierte Wissensverarbeitung in der Arbeitsplanung 59 3. Fazit und Lösungsansatz 63 4. Datenbeschaffung 69 4.1. Konvertierung des Datenbestandes 69 4.2. Aufbereitung des Datenbestandes 73 4.2.1. Identifizierung nicht aussagefähiger Attribute 73 4.2.2. Identifizierung nicht aussagefähiger Datenobjekte 74 4.2.3. Syntaktische und semantische Inkonsistenzen 74 4.2.4. Fehlende Werte 75 4.2.5. Fehlerhafte Werte 76 4.3. Fazit 76 5. Analyse der Wissensdomäne 77 5.1. Vorbetrachtungen 77 5.2. Informationsstruktur: Das CAD/CAM-Informationsmodell 80 5.2.1. Beschreibung des Werkstücks 81 5.2.2. Beschreibung der Bearbeitungsprozesses 82 5.3. Informationsgenerierung: CAD/CAM- gestützte NC-Programmierung 84 5.3.1. Geometrievorbereitung 85 5.3.2. Bestimmung des Operationsplans 86 5.3.3. Berechnung, Simulation und Bereitstellung 98 5.4. Ableitung und Formalisierung der Wissensziele 99 5.5. Zusammenfassung und weitere Vorgehensweise 100 6. Automatisierte Wissensakquisition 103 6.1. Lernen von sequenziellen Beziehungen 103 6.1.1. Analyseverfahren 103 6.1.2. Modellierung von Markov-Ketten 103 6.2. Lernen von ableitenden Beziehungen 106 6.2.1. Analyseverfahren 107 6.2.2. Induktion von Entscheidungsbäumen 111 6.3. Evaluation 120 6.4. Applikation 123 6.5. Standardisierung 124 6.5.1. Attribute mit diskretem Wertebereich 125 6.5.2. Attribute mit kontinuierlichem Wertebereich 127 6.6. Fazit 129 7. Ergebnisse 131 7.1. Datenselektion 131 7.2. Untersuchungsfeld 1: Regeln für Werkzeugfolgen 133 7.2.1. Transformation 134 7.2.2. Modellbildung 138 7.2.3. Regel-Anwendung 143 7.3. Untersuchungsfeld 2: Regeln für Werkzeuge 145 7.3.1. Transformation 145 7.3.2. Modellbildung (univariater Entscheidungsbaum) 148 7.3.3. Modellbildung (multivariater Entscheidungsbaum) 150 7.3.4. Standardisierung 154 7.3.5. Regel-Anwendung 161 7.4. Untersuchungsfeld 3: Regeln für Schnittwerte 162 7.4.1. Transformation 162 7.4.2. Modellbildung 162 7.4.3. Standardisierung 167 7.4.4. Regel-Anwendung 169 7.5. Fazit 170 8. Prototypische Realisierung 175 8.1. Wissensakquisitionsmodul 176 8.1.1. Datenkonverter 176 8.1.2. Lernprozessor 178 8.2. Wissensspeicherung und -verarbeitung im CAD/CAM-System 181 8.2.1. Automatische Verarbeitung von Anwendungswissen 181 8.2.2. Manuelle Verarbeitung von Anwendungswissen 183 8.2.3. Wissensspeicherung und -verarbeitung in hyperMILL® 185 8.3. Beispielhafte Anwendung 189 8.3.1. Globale Eingangsinformationen 189 8.3.2. Rechnergestützte wissensbasierte NC-Programmierung 190 9. Zusammenfassung und Ausblick 197 10. Anhang 201 Anhang A 201 Anhang B 202 Abkürzungsverzeichnis 203 Literaturverzeichnis 207

Durch den Einsatz von CAD/CAM-Technologien sollen potenzielle Fehlerquellen der handwerklich-manuellen Herstellung zahnmedizinischprothetischer Restaurationen eliminiert werden. Grundlage für die Fertigung einer prothetischen Restauration mittels CAD/CAM ist eine möglichst genaue Digitalisierung der klinischen Situation. In dieser Studie wurde die Genauigkeit der digitalen Erfassung von Zähnen unter experimentellen sowie unter klinischen Bedingungen mit dem CEREC-3D® System (intraoral) im Vergleich zu konventioneller Abformung und Modellerstellung mit anschließender extraoraler Digitalisierung (Digiscan) untersucht. Von einem Schulungsmodell wurde mit einer Doppelmischabformung ein Modell mit präpariertem Zahn 16 erzeugt und extraoral digitalisiert. Dieses Modell wurde simuliert intraoral sowie nach erneuter Abformung und Modellherstellung extraoral digitalisiert. Im Anschluss daran erfolgte die Zuordnung der einzelnen Datensätze auf das Referenz-CAD-Modell und die dreidimensionale Differenzberechnung. Die durch die Ethik-Kommission genehmigte klinische Studie umfasste zehn Probanden. Bei diesen zehn Probanden erfolgte eine konventionelle und optische Abformung des Oberkiefers. Aus der konventionellen Abformung entstand ein Modell, welches extraoral-optisch digitalisiert wurde. Diesen Daten wurde die optische Abformung zugeordnet. Die dreidimensionale Auswertung erfolgte analog der in-vitro Studie. Die Auswertung der in-vitro Daten lieferte mittlere dreidimensionale Abweichungen von ±17-35μm bei der Betrachtung vom präparierten Zahn 16 und seinen Nachbarzähnen. Betrachtete man nur den präparierten Zahn 16, zeigten sich mittlere Abweichungen um ±17μm. Im Vergleich dazu lag die berechnete mittlere Differenz bei der intraoralen Digitalisierung eines Quadranten mit ±26-81μm erheblich darüber. Im Registrierzentrum konnte die geringste Abweichung gefunden werden. Der konventionelle Verfahrensweg (Abformung – Modellherstellung – extraorale Digitalisierung) hingegen liefert eine Genauigkeit von ±9-19μm. Anhand der gewonnenen Ergebnisse kann man sagen, dass die CEREC-3D®Kamera für die Erfassung von Einzelzahnrestaurationen sowie gegebenenfalls kleinerer mehrspanniger Restaurationen geeignet ist. Größere Restaurationen hingegen übersteigen den Indikationsbereich des Systems und sollten extraoral über den Umweg einer Abformung digitalisiert werden. Klinische Parameter beeinflussen die Genauigkeit der intraoralen Digitalisierung in einem akzeptablen Maß. Dies wird anhand des Vergleiches der in-vitro mit den in-vivo Daten ersichtlich. Dabei ist die Puderschicht von durchschnittlich 28,6μm (51) bei der intraoralen Digitalisierung zu berücksichtigen. / Using CAD/CAM-technology in dentistry is supposed to reduce or eliminate potential sources of error resulting from the manual craftsmanship needed when making dental restorative restorations. For any CAD/CAM-made restoration, a digitalization as precise as possible is basic. In this study, the precision of the digital measurement of teeth was examined in-vitro and invivo. The intraoral CEREC-3D® system was compared with conventional impression taking and model making and subsequent digitalization (Digiscan). A one-stage putty-and-wash impression was taken from a training model. The first upper molar in this model was prepared for a full crown. The resulting gypsum model was extraorally digitized. This master model was digitized with simulated intraoral digitizing and, after taking again an impression and making a gypsum model, with extraoral digitizing. The data was then aligned to the reference CAD-model, and the threedimensional differences were calculated. The clinical trial included ten probands and was approved by the responsible ethical committee. From each proband, a conventional impression as well as an intraoral digitizing was made from the upper jaw. The gypsum model resulting from the impression was digitized extraorally, and the data was aligned to the data-sets of the intraoral digitizing. The threedimensional differences were calculated analogous to the in-vitro analysis. The threedimensional analysis showed mean differences between ±17 and 35 microns for the prepared tooth 16 and its neighboring teeth. Looking at tooth 16 alone, the mean differences were around ±17 microns. Compared to these values, the mean differences calculated for intraoral digitizing of a whole quadrant were considerably higher (±26-81 microns). The smallest mean deviations were found at the center of alignment. The conventional method (impression taking - model making - extraoral digitizing) showed a significantly higher precision (±9-19 microns). The results show that the CEREC-3D®camera is suitable for single tooth and short-span restorations. However, the indication is not given for long-span restorations using the intraoral system. Such restorations should always be made after conventional impression taking, model making and subsequent extraoral digitizing. The precision of the intraoral digitizing is influenced by clinical parameters in an acceptable way as shown by the comparison of invitro and in-vivo data. The powder-layer of average 28.6 microns (51) has to be taken into consideration, when using intraoral digitizing.

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy