O presente estudo teve por objetivo avaliar por meio da análise de freqüência de ressonância (AFR) o efeito da irradiação com laser de GaAlAs na estabilidade de implantes de titânio, como cociente de estabilidade do implante (ISQ) instalados em pacientes parcialmente edentados na região posterior da mandíbula; assim como avaliar a evolução da estabilidade dos implantes, durante o período de osseointegração. Foram selecionados 8 pacientes adultos, com boa saúde para a instalação cirúrgica de 30 implantes Xive S® (Dentsply). Portanto, foram instalados de 2 a 5 implantes por paciente, distribuídos bilateralmente. Cada paciente atuou como seu próprio controle. Os implantes do lado controle não foram irradiados, e os do lado experimental foram submetidos a terapia com laser de diodo GaAlAs com ?= 830 nm, densidade de energia de 8 j/cm2, potência de 100 mW, modo contínuo, de forma pontual em 20 pontos, durante 3 segundos por ponto. A primeira sessão de irradiação foi no pós-operatório imediato, sendo repetida a cada 48 horas nos primeiros 14 dias, totalizando 7 irradiações. Após a instalação dos implantes foi medida a estabilidade primária destes com o aparelho Osstell?. Novas medidas de ISQ foram realizadas após 10 dias, e 3, 6, 9 e 12 semanas. No momento da instalação, os valores de ISQ na região posterior da mandíbula oscilaram de 65-84 com média de 76, sofrendo queda significativa da estabilidade do 100 dia para a 6a semana no grupo irradiado e apresentando um aumento gradual a partir da 6a semana até a 12a semana. Os valores mais altos de ISQ foram observados no 100 dia no grupo irradiado, embora sem significância estatística, e os mais baixos foram observados na 6a semana em ambos os grupos. Não foi evidenciado o efeito do laser de GaAlAs na estabilidade dos implantes com o aparelho OsstellTM, porém não se pode afirmar que os padrões de reparação óssea e a taxa de osseointegração entre os implantes irradiados e não irradiados tenham sido similares. / JThe present study was carried out to evaluate the effect of irradiation with the GaALAs laser in the stability of titanium implants (ISQ), inserted in partially edentulous patients, by means of resonance frequency analysis (RFA); as well as to evaluate the evolution of the stability during the osseointegration processs. A group of 8 patients were seleted for the insertion of 30 implants (Xive S® - Dentsply). The implants in the control site were not irradiated, and the implants in the experimentall site were submitted to laser therapy with a GaAlAs with ?= 830 nm, energy density of 8 j/cm2, power of 100 mW, continuing mode, in 20 points, for 3 seconds per point. The first irradiation was immediately after the surgery, and it was repeated every 48 hours in the first 14 days, totalizing 7 irradiations. After the implants insertion, the primary stability was measured using Osstell?. New measurements were carried out after 10 days, 3, 6, 9, 12 weeks. The incial ISQ values ranged from 65-84, with a mean of 76, showing a significative decrease in the stability from the 10th day to the 6th weeks in the irradiated group, and showing a gradual increase from 6th to 12th week. The highest ISQ values were observed in the 10th day in the irradiated group, and the lower ISQ values were observed in the 6th week in both groups. The effect of the irradiation with GaAlAs laser in implant stability was not evicenced; however, it can not be affirmed that irradiated and not irradiated implants have similar bone repair patterns and osseointegration rates.

Dans ce travail de thèse, la texturation de surface d‟alliages de titane a été étudiée en utilisant un procédé d'écriture directe par laser femtoseconde dans le but d'améliorer la mouillabilité d‟implants dentaires et orthopédiques par les fluides biologiques et la minéralisation de la matrice (formation osseuse) tout en réduisant l'adhésion bactérienne et la formation de biofilmes. Des surfaces de titane (Ti-6Al-4Vet cp Ti) ont été micro-, nano-texturées par laser femtoseconde et une biofonctionnalisation de ces surfaces a été ajoutée ou non par greffage de peptides d'adhésion cellulaire (peptides RGD) en surface de ces différents matériaux. Les textures de surface peuvent être classées comme suit: (a) structures périodiques de surface induites par laser (LIPSS); (b) étalage de nanopiliers (NP); (c) étalage de micro colonnes recouvertes de LIPSS (MC-LIPSS) formant une distribution bimodale de rugosité. Nous avons montré que la texturation de surface par laser améliore la mouillabilité des surfaces avec de l'eau ainsi qu‟une solution saline tamponnée Hank's (HBSS) et amène une anisotropie de mouillage. Une minéralisation cellulaire est observée pour toutes les surfaces des deux alliages de titane lorsque des Cellules Souches Mésenchymateuses humaines (hMSC) sont cultivées dans un milieu ostéogénique. La minéralisation de la matrice et la formation de nodules osseux sont considérablement améliorées sur les surfaces texturées LIPSS et NP. Parallèlement,l'adhésion de Staphylococcus aureus et la formation de biofilmes sont considérablement réduites pour les surfaces texturées LIPSS et NP. La biofonctionnalisation des différentes surfaces texturées (cp Ti) par laser a été réalisée et caractérisée par spectroscopie de photoélectrons (XPS) et par microscopie à fluorescence en utilisant des peptides fluorescents. L‟ensemble des résultats obtenus suggèrent que la texturation de surface d'alliages de titane (Ti-6Al-4V et cp Ti) en utilisant une technique d‟écriture directe par laser femtoseconde est un procédé prometteur pour l'amélioration de la mouillabilité de la surface d'implants dentaires et orthopédiques par les fluides biologiques et leur ostéointégration (différenciation ostéoblastique et minéralisation de la matrice), tout en réduisant l‟adhésion de Staphylococcus aureus et la formation de biofilmes. Enfin, la combinaison de la texturation par laser et du greffage covalent d‟un principe actif (ici un peptide d‟adhésion cellulaire comme le peptide RGD) amènera indéniablement une bioactivité utile pour favoriser l'adhésion des hMSC et faciliter laformation osseuse. / In the present thesis the surface texturing of Ti alloys using femtosecond laser direct writing method is explored as a potential technique to enhance the wettability of dental and orthopaedic implants by biological fluids and matrix mineralisation (bone formation), while reducing bacteria adhesion and biofilmformation. The surface texture was combined with biofunctionalisation by covalent grafting of a RGD peptide sequence as well. The surface textures can be classified as follows: (a) Laser-Induced Periodic Surface Structures-LIPSS; (b) nanopillars arrays(NP); (c) arrays of microcolumns covered with LIPSS (MC-LIPSS), forming a bimodal roughness distribution. Laser texturing enhances surface wettability by water andHank‟s balanced salt solution (HBSS) and introduces wetting anisotropy, crucial incontrolling the wetting behaviour. Matrix mineralisation is observed for all surfaces of both Ti alloys when human mesenchymal stem cells (hMSCs) are cultured in osteogenic medium. Matrix mineralisation and formation of bone-like nodules are significantly enhanced on LIPSS and NP textured surfaces. On the contrary, Staphylococcus aureusadhesion and biofilm formation are significantly reduced for LIPSS and NP textured surfaces. The biofunctionalisation of the laser textured surfaces of cp Ti is sucessfully achieved. In general, these results suggest that surface texturing of Ti alloys using femtosecond laser direct writing is a promising method for enhancing surface wettability of dental and orthopaedic implants by biological fluids and their osseointegration (osteoblastic differentiation and matrix mineralisation), while reducing Staphylococcus aureus adhesion and biofilm formation. Finally, the combination of laser texturing and covalent grafting of a RGD peptide sequence may be potentially useful for increasing cell adhesion and facilitating bone formation.

Submitted master thesis deals with stress - strain analysis of jaw, with dental implant. The implant serve as a suitable pillar for crown or dental bridge, when one or more teeth are lost. The project is oriented on BOI (basale - oseo - integrable) dental implant type, which is produced by DENTALIHDE company. Stress – strain condition of the mandible system with implant have been established by computational simulation, with use of the final elements method. Important part of down jowl is simulated on with EDS and EDDS applied types of implants. After implementation the implant begins to heal. Therefore the special attention is paid to stress - strain states on various level of osteointegration. There is a detail description of production of single part computational model and his solving in the master thesis. Presentation of large chapter with results and subsequent alteration stress - strain analysis is part of the master thesis. Program SolidWorks 2005 was used to create the geometric model. Computational model and the actual solving was accomplished with use of ANSYS 11.0 and ANSYS Wor-kbench systems.