L’objectif de cette thèse est double : 1) contribuer à la production de connaissances dans le champ théorique de la didactique professionnelle sur les activités liées aux systèmes vivants ; 2) aider à la conception, à l’ingénierie pédagogique et à l’évaluation de l’EVAH VirTeaSy. L’examen de la littérature dans le domaine des EVAH dentaires montre que les EVAH « haptiques » semblent être les plus pertinents pour répondre aux problématiques de formation en implantologie. Cependant, bien que des études montrent leur efficacité du point de vue de l’apprentissage, il reste des problèmes à résoudre en termes de méthodologie de conception. En effet, la démarche de conception s’appuie couramment sur des collaborations entre experts métiers et informaticiens qui aboutissent au développement d’EVAH technocentrés. Afin de contourner les écueils constatés dans ce type de démarche, nous choisissons d’inclure les sciences humaines sur l’ensemble du processus de conception de l’EVAH. Pour identifier les compétences à viser dans l’EVAH, nous mobilisons, dans le cadre de la didactique professionnelle, une analyse de l’activité. Celle-ci se finalise par l’identification de la structure conceptuelle de la situation reposant sur des concepts organisateurs de l’activité en liens avec des variables et des indicateurs. Notre première étude s’attache ainsi à identifier la structure conceptuelle de la situation en implantologie dentaire. Au cours de situations réelles de pose d’implant dentaire, des données d’enregistrement ont été recueillies et complétées par des verbalisations obtenues lors d’entretiens d’auto-confrontation. L’analyse des données à l’aide de la méthodologie des catégories conceptualisantes nous a permis de faire émerger les concepts organisant l’activité des dix chirurgiens-dentistes observés. L’activité d’implantologie consiste à réaliser un compromis entre le concept organisateur « d’émergence » qui permet de réaliser le projet prothétique et le concept « d’ancrage » qui permet au projet prothétique de durer dans le temps. Ces deux concepts n’étant pas toujours convergents. La conception de VirTeaSy s’appuie sur les résultats de l’étude 1 et se réalise grâce à une méthodologie en cinq étapes. Notre expérience de cette mise en œuvre méthodologique montre qu’il faut constamment faire des choix. Ces choix reposent dans un premier temps sur la littérature et conduisent à définir des éléments de conception généraux. Ces éléments sont ensuite spécifiés à l’aide des résultats de l’analyse de l’activité, celle-ci prend alors toute sa pertinence afin que l’EVAH traduise les compétences-clefs que les apprenants doivent construire pour être efficaces. L’étude 2 porte sur le transfert d’apprentissage du virtuel au réel. Pour ce faire, trente-deux dentistes sont répartis de façon aléatoire dans trois groupes : un groupe (n=10) nommé GRV formé dans VirTeaSy, un groupe (n=11) nommé GT formé de manière traditionnelle et un groupe (n=11) nommé contrôle (GC) ne recevant aucune formation. Tous les sujets sont novices en implantologie dentaire. Une semaine après que chaque groupe ait suivit sa formation, tous les sujets réalisent la tâche de réinvestissement consistant à poser un implant sur un cadavre humain. Pour chaque sujet, nous mesurons, à l’aide d’un scanner, la différence entre la performance demandée et la performance réalisée. Les mesures portent sur l’angulation, l’émergence et la centration. Nos résultats ne montrent pas de différence significative entre les trois groupes. Des prolongements à cette thèse sont en cours de mise en œuvre. Il s’agit : 1) d’étendre l’analyse de l’activité à une population internationale ; 2) d’évaluer VirTeaSy grâce à différents protocoles incluant les fonctionnalités issues de l’analyse de l’activité ; 3) d’élargir le périmètre de formation de VirTeaSy à l’odontologie. / The objective of this thesis is twofold: 1) to build knowledge in the theoretical field “didactique professionnelle” for living systems activities; 2) to help design and assess VirTeaSy. An analysis of the literature in dental V.E.T showed that “haptic V.E.T.” seem to be the most relevant for the challenge of training in dental implantology. However, some studies show, there are still problems to be solved in terms of design methodology. Indeed, the usual design approach relies on collaboration between dental experts and IT engineers. In this approach, IT engineers carry on the V.E.T. development. This means that the result is often a V.E.T. developed from an IT point of view rather than from a learning point of view. To overcome issues associated with this type of approach, we have chosen to include experts in pedagogy in design process of Virteasy.We have undertaken an analysis of activity within the framework of “didactique professionnelle” in order to identify the skills which the students were going to learn with our V.E.T. The final aim of this analysis is identification of the “conceptual structure of the situation” (structure conceptuelle de la situation) based on “organizing concepts” (concept organisateur) of the activity links with variables and indicators. Our first study deals with identifying the “conceptual structure of the situation” in dental implantology. Recorded data (movies) were gathered from ten dentist experts during a live implant surgery. This was followed by in depth interviews within the dentists watching the recording of the surgery and verbalizing their mental process during the procedure. A content analysis of the interview showed that the mental process of the dentist performing an implantology procedure is based on two concepts. The first is concept is “emergence”, the dentist’s actions are guided by the prosthetic teeth which is going to be fitted on the implant. The second is “anchorage”, the dentist’s action are guided by the longevity of the implant. These two concepts are not always compatible which shows the real challenge faced by implant experts. VirTeaSy design is based on the results of Study 1 and make with a five-step methodology Our experience shows that a lot decision have to be made at each stage of the methodology. These decisions were based initially on literature and led to the definition of general design elements. These components were then specified using the results of the activity analysis. This showed how important and relevant an activity analysis was in making specific and accurate decisions in the design of V.E.T. Because of this process, the V.E.T. is enable to teach skills and competences that students must acquire to perform procedures in real life situations. The study 2 focused on learning transfer from virtual to reality. To do this, thirty-two dentists are randomized into three groups: one group (n = 10) named Group with Virtual Training (GVT); one group (n = 11) named Group with Traditional Training (GTT) and one group (n = 11 ) named Control Group (CG) receiving no training. All subjects were novice to dental implantology. One week after training, all subjects had to perform a task during which they had to demonstrate and apply the skills acquired during the training (“the reinvestment” task consisting of placing an implant on a human corpse). For each subject, we measured the difference between the required performance and the performance achieved using a scanner. We recorded three kind of measure: angle; depth and center. The results showed no significant difference between the three groups. Extensions of this thesis are being implemented. Some are based on international partnerships with well-known Universities. These extensions are: 1) to extend the activity analysis to an international population, 2) To evaluate VirTeaSy through various protocols including features from the activity analysis, 3) To broaden the scope of using VirTeasy in dental training.

Ce travail de recherche vise à développer des méthodologies d’évaluation mécanique des implants dentaires, de leurs composants prothétiques et de l’interaction avec les tissus osseux de la mâchoire. D’après l’Organisation Mondiale de la Santé (OMS), 15 à 20% de la population âgée de 35 à 44 ans est atteint de problèmes d’édentation partielle et près de 30% de la population âgée de 65 à 74 d’édentation totale. Cela représente donc approximativement 7 millions de personnes en France ayant subi des pertes de dents durant leur vie. Les traitements proposés par l’implantologie dentaire sont devenus des solutions efficaces pour les problèmes d’édentation avec des taux de réussite cliniques supérieurs à 90%. Cependant, des complications cliniques existent, caractérisées par des inflammations ou des pertes partielles des tissus environnants. Les dentistes étant responsables du choix du traitement thérapeutique pour leurs patients, la prise d’une décision appropriée est capitale et exige une compréhension des risques et des bénéfices. C’est dans ce contexte qu’une première méthodologie d’évaluation a été développée pour améliorer le design des implants dentaires de type endosseux, dans les conditions de la norme de certification ISO 14801. La méthodologie est basée sur des approches numériques par Analyse d’Eléments Finis. Ensuite, des approches théoriques et des données cliniques ont été utilisées pour évaluer le comportement mécanique des tissus osseux de la mâchoire face aux différentes configurations par implants dentaires et leurs composants prothétiques. / The research purpose in this study is to develop of mechanical evaluation methods to dental implants, their prosthetic components and the interactions with bone tissues in mandible zone. According to the World Health Organization (WHO), 15 to 20% of population from 35 to 44 years old is reached of partial edentulism problems and about 30% of population from 65 to 74 years old is reached of complete edentulism problems. This represents approximately 7 million people in France who have lost teeth during their lifetime. Treatments proposed by dental implantology have become effective solutions for edentulous patients with clinical success rates greater than 90%. However, clinical complications exist, characterized by inflammation or partial losses of the surrounding tissues. Dentists are responsible for the treatment choice for their patients; an appropriate decision is crucial and requires an understanding of the benefits and risks. In this context, a first methodology was developed for evaluated the endosseous dental implants under the conditions of the ISO 14801 certification standard. This methodology is based with an approach numerical by Finite Element Analysis (FEA). Furthermore, theoretical approaches and clinical data were used to evaluate the mechanical resistance of the bone tissues in the jaw with different dental implant configurations and their prosthetic components.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais / The aim of this work is to determine the life of twist drills used for dental implantology when drilling bovine tibia bones and to study the influence of the cutting conditions. The inputs variables considered were the cutting tool material, the feed velocity and the spindle speed. The outputs variables monitored were the number of drilled holes, the workpiece temperature, the thrust force and the tool wear. The tests were carried out in a CNC machine center and the cutting parameters were varied following a 23 experimental design. Three types of uncoated tool materials were used, a martensitic stainless steel (M340/Böhler), an austenitic stainless steel (AISI 316L) and a ceramic (zircon stabilized with Y2O3). The tool lives were expressed by the number of drilled holes considering a limit of the workpiece temperature of 47ºC, used as the end of tool life criterion. The temperatures were monitored by using three thermocouples of the type T (cupper-constantan) inserted in the work material samples, positioned very close to the drill wall. The thrust force was measured with a Kistler rotating dynamometer. A data acquisition board and a computer were used for automation of the measurement system. A mixture of 20% of car radiator fluid and water was applied as coolant (irrigation) with a flow rate of 160 ml/min. The results showed that the martensitic stainless steel outperformed the austenitic stainless steel and the ceramic material. The lowest temperatures and a conformity state at the clinic standard for thrust force values were obtained with the highest cutting parameters (45 mm/min and 2500 rpm). It was observed that the higher feed velocity promoted a temperature drop, while the higher spindle speed decreased the thrust force. / O objetivo deste trabalho é determinar a vida de brocas para implantodontia através de furação em tíbia bovina e estudar a influência das condições de corte utilizadas. As variáveis de entrada do trabalho foram o material de ferramenta, a velocidade de avanço e a rotação. E as variáveis de saída monitoradas foram o número de furos realizados, a temperatura próxima à parede óssea, a força de avanço e o desgaste das ferramentas. Os testes foram executados em um Centro de Usinagem variando os parâmetros de corte seguindo um planejamento experimental 23. Três tipos de materiais de ferramenta não revestidos foram utilizados, um aço inoxidável martensítico (M340/Böhler), um aço inoxidável austenítico (AISI 316L) e um cerâmico (zircônia estabilizada com Y2O3). A vida da ferramenta foi expressa pelo número de furos realizados considerando como critério de fim de vida a temperatura na peça igual a 47ºC. As temperaturas foram monitoradas pelo uso de três termopares do tipo T (cobre-constantan) inseridos no corpo-de-prova e posicionados próximo à parede do furo. A força de avanço foi medida com um dinamômetro rotativo Kistler. Uma placa de aquisição de dados e um computador foram utilizados para a automação do sistema de medição. Uma mistura de 20% de líquido de arrefecimento automotivo foi utilizada como refrigerante (irrigação) a uma vazão de 160 ml/min. Os resultados mostraram que o aço inoxidável martensítico superou o aço inoxidável austenítico e o material cerâmico. Menores temperaturas e um estado de conformidade aos padrões clínicos para valores de força de avanço foram obtidos com os maiores parâmetros de corte (45 mm/min e 2500 rpm). Observou-se que velocidade de avanço alta promove principalmente a queda da temperatura, enquanto a rotação elevada à queda na força de avanço. / Mestre em Engenharia Mecânica