Browsing by Keyword "Dental implants"
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Item Biological response of laser macrostructured and oxidized titanium alloy: An in vitro and in vivo study(2011-09) Paz, María Dolores; Iñaki Álava, J.; Goikoetxea, Leire; Chiussi, Stefano; Díaz-Güemes, Idoia; Usón, Jesus; Sánchez, Francisco; León, Betty; BiomaterialesPurpose: To assess both the in vitro and in vivo biological response of a laser modified surface in an integrated manner. A combined innovative approach applies lasers to macrostructure as well as to oxidize the surface of titanium alloy implants. Materials and methods: A Nd:YAG marking and ArF excimer lasers were used for macrostructuring and UV-oxidizing the surface of Ti6Al4V discs, respectively. Human fetal osteoblastic cell culture and a sheep tibia model were used to assess the cell response and the osseogeneration capability of as-machined, laser macrostructured and laser macrostructured and oxidized surfaces. Results: In vitro: Laser macrostructuration alone did not promote cell response. Cellular proliferation was enhanced by the additional UV laser oxidation. In vivo: A greater significant percentage of bone-implant contact was obtained for both laser treated surfaces compared to machine-turned control samples, three months after implantation, in spite of the low cellular response for macrostructured samples. The use of sheep model for six months appears to be less adequate for a comparison because of the high level of bone integration in all samples. In spite of the often reported positive effect of titanium oxidation on the triggering of faster osseointegration, in this experiment the additional UV laser oxidation did not lead to a significant in vivo improvement. Conclusions: Laser macrostructuration of titanium alloy surfaces appears to promote bone apposition and may therefore constitute a promising surface modification strategy. In animal models, the natural process of titanium surface oxidation, because of physiologic fluids, alters properties observed in vitro with cells.Item Histomorphometric study of ion implantation and diamond-like carbon as dental implant surface treatments in beagle dogs(2007-03) De Maeztu, Miguel A.; Braceras, Iñigo; Alava, J. Iñaki; Sánchez-Garcés, M. Angeles; Gay-Escoda, Cosme; INGENIERÍA DE SUPERFICIESPurpose: Improvements in the bone-implant interface can provide clinical benefits, such as increasing the amount of bone in contact with the implant and shortening the time required to achieve sufficient bone appositioning to allow early prosthetic loading. The present study describes the results obtained with 2 new surface treatments: (a) CO ion implantation; and (b) diamond-like carbon (DLC) coating. Materials and Methods: Each group (ion implantation, DLC, and the control group, turned titanium) consisted of 12 samples. Beagle dogs subjected to previous partial edentulation were used. Dual histologic evaluation was made of percentage bone-implant contact (% BIC) of all samples based on conventional histomorphometric analysis and environmental scanning electron microscopy (ESEM). Results: The results obtained after 3 and 6 months of dental implant placement showed greater and faster bone integration in the CO ion implantation group (61% and 62% BIC, respectively) compared with the DLC group (47% and 50%); the data corresponding to the ion implanted samples were statistically significant compared with the control group (33% and 49% BIC after 3 and 6 months, respectively). Conclusions: The results showed improved % BIC for implants with ion-implanted surfaces in comparison to DLC coating and machined controls. Furthermore, bone integration appeared to be accelerated in the ion implantation group, since high % BIC values were recorded in the early stages after in vivo implantation.Item Interaction of engineered surfaces with the living world: Ion implantation vs. osseointegration(2007-08-05) Braceras, I.; Alava, J. I.; Goikoetxea, L.; de Maeztu, M. A.; Onate, J. I.; Biomateriales; Tecnalia Research & InnovationThe reaction of living tissues to foreign materials is a highly complex process that currently is insufficiently understood. Nevertheless, if specific reactions are to be promoted, this understanding is highly valuable and thus a significant research effort is being devoted to this issue. Typically, when a biomaterial is inserted in living tissue, proteins and other bio-molecules will adsorb to the surface. As this protein layer will mediate the interaction of the biomaterial with the living world, the consequent reactions will be highly dependant on this very first stage. Furthermore, different materials, i.e. surfaces, typically elicit a very different tissue response. It is commonly admitted that the primary adsorption depends heavily on the surface chemistry, surface topography and surface physical characteristics. Interactions between surface micro-topography and living cells have been widely studied, but protein specific reactions versus nano-topography have been barely explored. Ion beam modification of surfaces, which affect these key properties, can therefore be (i) a powerful tool to advance in the understanding of these nanoscale phenomena and (ii) useful as an industrial treatment of high value-added medical devices. This work will explore the application of ion beam based surface treatments to cause specific reactions in hard tissue regeneration. A variety of in vitro and in vivo results are presented corresponding to ion implantation treatments promoting "osseointegration" or intimate binding between the biomaterial and the living tissue, without any soft tissue interlayer, and an overview of the mechanism behind is offered, i.e. among other behaviour of osteoblasts, signalling proteins as the integrins, nanotopographic parameters.