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Osseointegration capacity and good mechanical behavior are key to the success of the dental implant. In many investigations, comparisons of properties are made using different dental implant designs and therefore the results can be influenced by the macrodesign of the dental implant. In this work, studies were carried out with the same dental implant model using different roughness and different materials—commercially pure titanium (grade 4) and zirconia. For this purpose, 80 smooth passivated titanium (Ti), 80 smooth zirconia (ZrO2), and 80 rough passivated titanium (Ti-R) dental implants were used. The samples were characterized by their roughness, wettability, surface energy, residual stresses, and fatigue behavior. The implants were implanted in minipigs for 4 and 12 weeks. The animals were sacrificed, and histological studies were carried out to determine the osseointegration parameters for each of the implantation times. Ti and ZrO2 dental implants have very similar wettability and surface energy properties. However, the roughness causes a decrease in the hydrophilic character and a decrease of the total surface energy and especially the dispersive component, while the polar component is higher. Due to the compressive residual stresses of alumina sandblasting, the rough dental implant has the best fatigue behavior, followed by Ti and due to the lack of toughness and rapid crack propagation the ZrO2 implants have the worst fatigue behavior. The bone index contact (BIC) values for 4 weeks were around 25% for Ti, 32% for ZrO2, and 45% for Ti-R. After 12 weeks the Ti dental implants increased to 42%, for Ti, 43% for ZrO2, and an important increase to 76% was observed for Ti-R implants. In vivo results showed that the key factor that improves osseointegration is roughness. There was no significant difference between ZrO2 and Ti implants without sandblasting. info:eu-repo/semantics/publishedVersion

Background: The objective of this study was to evaluate the accumulation of ions in blood and organs caused by Ti metal particles in a mandibular defect in rats, together with a description of the local reaction of oral tissues to these titanium alloy debris. Methods: Twenty Sprague-Dawley rats were randomly distributed into three groups: an experimental group with a mandibular bone defect filled with metallic debris obtained by implantoplasty; a positive control group; and a negative control group. Thirty days after surgery, the rats were euthanized and perilesional tissue surrounding the mandibular defect was removed, together with the lungs, spleen, liver and brain. Two blood samples were collected: immediately before surgery and before euthanasia. The perilesional tissue was histologically analyzed using hematoxylin-eosin staining, and titanium, aluminum and vanadium ion concentrations in blood and organs were measured by TQ-ICP-MS. Descriptive and bivariate analyses of the data were performed. Results: All rats with implanted metal debris showed metal particles and a bone fracture callus on the osseous defect. The metal particles were surrounded by a foreign body reaction characterized by the presence of histiocytes and multinucleated giant cells. The experimental group had a significant higher concentration of Ti ions in all studied organs except lung tissue (p < 0.05). In addition, there were more V ions in the brain in the experimental group (p = 0.008). Conclusions: Although further studies are required to confirm the clinical relevance of these results, Ti metal particles in the jaw might increase the concentration of metal ions in vital organs and induce a foreign body reaction. This article is protected by copyright. All rights reserved. Keywords: Ion release; Ti6Al4V; implantoplasty; metal particles; peri-implantitis; titanium.

The augmentation of the alveolar crest after the loss of one or several teeth can be carried out using different bone augmentation techniques. These techniques include bone distraction, ridge expansion, bone block grafts, etc. Guided bone regeneration is an alternative to increase the volume of the hard tissues for the subsequent placement of the implants in the optimal three-dimensional position. The objective of this paper is to show a case report of the use of customized titanium mesh for posterior vertical bone regeneration. Case report and Results: A 59-year-old woman comes to rehabilitate edentulous spaces with implants. After taking the anamnesis and the intra and extraoral exploration, a vertical and horizontal bone defect is observed in the third quadrant. After the radiological study with CBCT, a bone height of 6.04 mm to the inferior alveolar nerve and a width of the bone crest of 3.95 mm was observed. It was decided to carry out a regeneration with a preformed titanium mesh (Avinent®, Santpedor, Spain) and four microscrews (Avinent®, Santpedor, Spain). The flap was closed without tension. Regular check-ups were performed without complications. At 7 months, the mesh was removed and two osteoingrated implants (Avinent®, Santpedor, Spain) were placed with a torque greater than 45 N/cm and an ISQ of 82 and 57 N/cm, respectively. The bone gain obtained was 1.84 and 1.92 mm in width and 4.2 and 3.78 mm in height for positions 3.5 and 3.6. The newly formed bone, obtained by trephine, was well-structured and histologically indistinguishable from the previous bone. Conclusion: The use of a customized pre-formed titanium mesh together with the mixture of autologous bone and xenograft is a feasible and predictable technique for vertical bone regeneration.

The techniques used in oral implantology to remove bacterial biofilm from the surface of implants by machining the titanium surface (implantoplasty) or by placing rough dental implants through friction with the cortical bone generate a large release of particles. In this work, we performed a simulation of particle generation following clinical protocols. The particles were characterized for commercially pure titanium with particle sizes of 5, 10, 15, and 30 μm. The aim was to determine the effect of particle size and chemical composition of the implant on the immune response. For this purpose, their morphology and possible contamination were characterized by scanning electron microscopy and X-ray microanalysis. In addition, the granulometry, specific surface area, release of metal ions into the medium, and studies of cytocompatibility, gene expression, and cytokine release linked to the inflammatory process were studied. The release of ions for titanium particles showed levels below 800 ppb for all sizes. Smaller particle sizes showed less cytotoxicity, although particles of 15 μm presented higher levels of cytocompatibility. In addition, inflammatory markers (TNFα and Il-1β) were higher compared to larger titanium. Specifically, particles of 15 μm presented a lower proinflammatory and higher anti-inflammatory response as characterized by gene expression and cytokine release, compared to control or smaller particles. Therefore, in general, there is a greater tendency for smaller particles to produce greater toxicity and a greater proinflammatory response. info:eu-repo/semantics/publishedVersion

Implantoplasty is a mechanical decontamination technique that consists of polishing the supra-osseous component of the dental implant with peri-implantitis. This technique releases metal particles in the form of metal swarf and dust into the peri-implant environment. In the present in vitro study, the following physicochemical characterization tests were carried out: specific surface area, granulometry, contact angle, crystalline structure, morphology, and ion release. Besides, cytotoxicity was in turn evaluated by determining the fibroblastic and osteoblastic cell viability. As a result, the metal debris obtained by implantoplasty presented an equivalent diameter value of 159 µm (range 6–1850 µm) and a specific surface area of 0.3 m2/g on average. The particle had a plate-like shape of different sizes. The release of vanadium ions in Hank’s solution at 37 °C showed no signs of stabilization and was greater than that of titanium and aluminum ions, which means that the alloy suffers from a degradation. The particles exhibited cytotoxic effects upon human osteoblastic and fibroblastic cells in the whole extract. In conclusion, metal debris released by implantoplasty showed different sizes, surface structures and shapes. Vanadium ion levels were higher than that those of the other metal ions, and cell viability assays showed that these particles produce a significant loss of cytocompatibility on osteoblasts and fibroblasts, which means that the main cells of the peri-implant tissues might be injured. info:eu-repo/semantics/publishedVersion

The surface modification by the formation of apatitic compounds, such as hydroxyapatite, improves biological fixation implants at an early stage after implantation. The structure, which is identical to mineral content of human bone, has the potential to be osteoinductive and/or osteoconductive materials. These calcium phosphates provoke the action of the cell signals that interact with the surface after implantation in order to quickly regenerate bone in contact with dental implants with mineral coating. A new generation of calcium phosphate coatings applied on the titanium surfaces of dental implants using laser, plasma-sprayed, laser-ablation, or electrochemical deposition processes produces that response. However, these modifications produce failures and bad responses in long-term behavior. Calcium phosphates films result in heterogeneous degradation due to the lack of crystallinity of the phosphates with a fast dissolution; conversely, the film presents cracks, which produce fractures in the coating. New thermochemical treatments have been developed to obtain biomimetic surfaces with calcium phosphate compounds that overcome the aforementioned problems. Among them, the chemical modification using biomineralization treatments has been extended to other materials, including composites, bioceramics, biopolymers, peptides, organic molecules, and other metallic materials, showing the potential for growing a calcium phosphate layer under biomimetic conditions. Ramón y Cajal Beca a C.M.-M. RYC-2015-18566 Cofinanciados por la UE a través de la Unión Europea Fondos de Desarrollo Regional

Featured Application In this paper, a fast, one-step method to prepare acrylate-based coatings on titanium through the atmospheric pressure plasma polymerization of HEMA is described. The coating shows lower surface bacterial adhesion and enhanced cell adhesion when compared with pristine titanium. Dental implants can fail due to various factors, in which bad tissue integration is believed to have a significant role. Specific properties of the implant surface, such as its chemistry and roughness, are of paramount importance to address specific cell responses, such as the adsorption of proteins, as well as the adhesion and differentiation of cells, which are suitable for biomaterial and tissue engineering. In this study, an acrylate-containing coating was produced on titanium surfaces through the atmospheric pressure plasma treatment of a liquid precursor, 2-hydroxyethyl methacrylate. A hydrophilic coating was obtained, showing retention of the monomer chemistry as assessed by FTIR analysis and XPS. Enhanced fibroblast adhesion and decreased Staphylococcus aureus and Escherichia coli adhesion were recorded, showing that this is a suitable method to produce biocompatible coatings with a reduced bacterial adhesion.

Background Peri-implantitis is a biological complication that affects soft and hard tissues around dental implants. Implantoplasty (IP) polishes the exposed implant surface, to decontaminate it and make it less prone to bacterial colonization. This study investigates whether a higher clinical crown-to-implant-ratio (CIR) reduces implant fracture resistance and whether implants are more fracture-prone after IP in the presence of 50% of bone loss. Methods Forty-eight narrow platform (3.5 mm) 15 mm long titanium dental implants with a rough surface and hexagonal external connection were placed in standardized bone-like resin casts leaving 7.5 mm exposed. Half were selected for IP. The IP and control groups were each divided into 3 subgroups with different clinical CIRs (2:1, 2.5:1 and 3:1). The implant wall width measurements were calculated using the software ImageJ v.1.51 through the analysis of plain x-ray examination of all the samples using standardized mounts. A fracture test was performed and scanning electron microscopy was used to evaluate maximum compression force (Fmax) and implant fractures. Results IP significantly reduced the implant wall width (P max was significantly higher in the 2:1 subgroup (control = 1276.16 N ± 169.75; IP = 1211.70 N ± 281.64) compared with the 2.5:1 (control = 815.22 N ± 185.58, P P P P P = 0.037) of the Fmax between the controls and the IP implants. Most fractures were located in the platform area. Only 5 implants with IP of the 2:1 CIR subgroup had a different fracture location (4 fractures in the implant body and 1 in the prosthetic screw). Conclusions IP significantly reduces the fracture resistance of implants with a 2.5:1 CIR. The results also suggest that the CIR seems to be a more relevant variable when considering the resistance to fracture of implants, since significant reductions were observed when unfavorable CIR subgroups (2.5:1 and 3:1 CIR) were compared with the 2:1 CIR samples.

Infections related to dental implants are a common complication that can ultimately lead to implant failure, and thereby carries significant health and economic costs. In order to ward off these infections, this paper explores the immobilization of triethoxysilylpropyl succinic anhydride (TESPSA, TSP) silane onto dental implants, and the interaction of two distinct monospecies biofilms and an oral plaque with the coated titanium samples. To this end, titanium disks from prior machining were first activated by a NaOH treatment and further functionalized with TESPSA silane. A porous sodium titanate surface was observed by scanning electron microscopy and X-ray photoelectron spectroscopy analyses confirmed the presence of TESPSA on the titanium samples (8.4% for Ti&ndash, N-TSP). Furthermore, a lactate dehydrogenase assay concluded that TESPSA did not have a negative effect on the viability of human fibroblasts. Importantly, the in vitro effect of modified surfaces against Streptococcus sanguinis, Lactobacillus salivarius and oral plaque were studied using a viable bacterial adhesion assay. A significant reduction was achieved in all cases but, as expected, with different effectiveness against simple mono-species biofilm (ratio dead/live of 0.4) and complete oral biofilm (ratio dead/live of 0.6). Nevertheless, this approach holds a great potential to provide dental implants with antimicrobial properties.

The purpose of this study is to assess the use of grade V titanium mini transitional implants (MTIs) immediately loaded by a temporary overdenture. For this, a histomorphometric analysis of the bone area fraction occupancy (BAFO) was performed by backscattered scanning electron microscopy (BS-SEM). Four female patients were submitted to surgery in which two MTIs were installed and immediately loaded with a temporary acrylic prosthesis. During the same surgery, two regular diameter implants were placed inside the bone and maintained without mechanical load. After 8 months, the MTIs were extracted using a trephine and processed for ultrastructural bone analysis by BS-SEM, and the regular-diameter implants were loaded with an overdenture device. A total of 243 BAFOs of MTIs were analyzed, of which 94 were mainly filled with cortical bone, while 149 were mainly filled with trabecular bone. Bone tissue analysis considering the total BAFOs with calcified tissues showed 72.13% lamellar bone, 26.04% woven bone, and 1.82% chondroid bone without significant differences between the samples. This study revealed that grade V titanium used in immediately loaded MTI was successfully osseointegrated by a mature and vascularized bone tissue as assessed from the BAFO.

Titanium dental implants are widely used for the replacement of damaged teeth. However, bacterial infections at the interface between soft tissues and the implant can impair the functionality of the device and lead to failure. In this work, the preparation of an antifouling coating of polyethylene glycol (PEG) on titanium by pulsed electrodeposition was investigated in order to reduce Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) adhesion while maintaining human fibroblast adhesion. Different pulsed conditions were prepared and characterized by contact angle, Focused Ion Beam (FIB), Fourier Transformed Infrared Spectroscopy in the Attenuated Total Reflectance mode (ATR-FTIR), and X-ray photoelectron spectroscopy (XPS). XPS tested fibronectin adsorption. S. aureus, E. coli and human fibroblast adhesion was tested in vitro in both mono and co-culture settings. Physicochemical characterization proved useful for confirming the presence of PEG and evaluating the efficiency of the coating methods. Fibronectin adsorption decreased for all of the conditions, but an adsorption of 20% when compared to titanium was maintained, which supported fibroblast adhesion on the surfaces. In contrast, S. aureus and E. coli attachment on coated surfaces decreased up to 90% vs. control titanium. Co-culture studies with the two bacterial strains and human fibroblasts showed the efficacy of the coatings to allow for eukaryotic cell adhesion, even in the presence of pre-adhered bacteria.

Two-pieces dental implants must provide stability of the implant-abutment-interface. The connection type and platform diameter could influence the biomechanical resistance and stress distribution. This study aims to evaluate the fatigue for different types of connections, external and internal, and different platform diameters. Three implant designs with the same length were used: (a) external hexagon/narrow platform, (b) internal double hexagon/narrow platform, (c) internal octagon/regular platform. A fatigue test was developed to establish the number of cycles needed before fracture. A 30&ordm, oblique load with a sinusoidal function of fatigue at a frequency of 15 Hz and 10% stress variation was applied to each system. The fatigue load limit (FLL) for design (a) was 190N, being the nominal-curvature-moment (NCM) = 1.045, FLL = 150 N, with a NCM = 0.825 for (b), and FLL = 325 N, with a NCM = 1.788 for (c). The platform diameter affects the FLL, obtaining lower FLL on a narrow platform. The connection type interferes with the implant walls&rsquo, width, especially in narrow implants, making internal connections more unstable at this level. Long-term clinical studies to assess the restoration&rsquo, s success rate and survival are mandatory.

Background:The topographical features on the surface of dental implants have been considered as a critical parameter for enhancing the osseointegration of implants. In this work, we proposed a surface obtained by a combination of shot blasting and double acid etching. The double acid etching was hypothesized to increase the submicron topography and hence further stimulate the biological properties of the titanium implant.Methods:The topographical features (surface roughness and real surface area), wettability and surface chemical composition were analyzed.Results:The results showed that the proposed method produced a dual roughness, mainly composed of randomly distributed peaks and valleys with a superimposed nanoroughness, and hence with an increased specific surface area. Despite the fact that the proposed method does not introduce significant chemical changes, this treatment combination slightly increased the amount of titanium available on the surface, reducing potential surface contaminants. Furthermore, the surface showed increased contact angle values demonstrating an enhanced hydrophobicity on the surface. The biological behavior of the implants was then assessed by culturing osteoblast-like cells on the surface, showing enhanced osteoblast adhesion, proliferation and differentiation on the novel surface.Conclusions:Based on these results, the described surface with dual roughness obtained by double acid etching may be a novel route to obtain key features on the surface to enhance the osseointegration of the implant. Our approach is a simple method to obtain a dual roughness that mimics the bone structure modified by osteoclasts and increases surface area, which enhances osseointegration of dental implants.

Sixty-four fractured commercially pure titanium (cp-Ti) narrow dental implants (NDIs) with similar macrogeometry and connection designs were studied after different implantation times in humans in order to determine their reliability and to evaluate the causes of the fracture. These NDIs were compared with other similar implants, made with alloyed titanium with 15% Zr and with 12% strained titanium. Original implants were tested under static and fatigue conditions, simulating the tri-axial loads in the mouth by means of a Bionix hydraulic test machine. Fractography was studied using field-emission scanning electron microscopy (FSEM). The results showed that cp-Ti NDI exhibits low strength for mechanical cycling, and the alloyed Ti and strained titanium increase the mechanical strength, guaranteeing long term mechanical behavior. NDIs fractured due to fatigue, and, in some cases, the presence of cracks in the original NDIs quickly led to fracture. These cracks were attributed to plastic deformation during machining were found to be exacerbated due to acid etching in the passivation process. All cases of fracture were cp-Ti dental implants due to the low fatigue limit. The results show that, when titanium is alloyed or cold-worked, the fatigue limit is higher than cp-Ti. This in vitro research will help clinicians to select a better NDI system for safer treatment. info:eu-repo/semantics/acceptedVersion

The surface modifications of titanium dental implants play important roles in the enhancement of osseointegration. The objective of the present study was to test two different implant surface treatments on a rabbit model to investigate the osseointegration. The tested surfaces were: a) acid-etched surface with sandblasting treatment (SA) and b) an oxidized implant surface (OS). The roughness was measured by an interferometeric microscope with white light and the residual stress of the surfaces was measured with X-ray residual stress Bragg–Bentano diffraction. Six New Zealand white rabbits were used for the in vivo study. Implants with the two different surfaces (SA and OS) were inserted in the femoral bone. After 12 weeks of implantation, histological and histomorphometric analyses of the blocks containing the implants and the surrounding bone were performed. All the implants were correctly implanted and no signs of infection were observed. SA and OS surfaces were both surrounded by newly formed trabeculae. Histomorphometric analysis revealed that the bone–implant contact % (BIC) was higher around the SA implants (53.49 ± 8.46) than around the OS implants (50.94 ± 16.42), although there were no significant statistical differences among them. Both implant surfaces (SA and OS) demonstrated a good bone response with significant amounts of newly formed bone along the implant surface after 12 weeks of implantation. These results confirmed the importance of the topography and physico–chemical properties of dental implants in the osseointegration. The authors are grateful to the Spanish Government and European Union FEDER by the concession of the project RTI2018-098075-B-C22 SI

Biomimetic design is a key tenet of orthopedic device technology, and in particular the development of responsive surfaces that promote ion exchange with interfacing tissues, facilitating the ionic events that occur naturally during bone repair, hold promise in orthopedic fixation strategies. Non-bioactive nanostructured titanium implants treated by shot-blasting and acid-etching (AE) induced higher bone implant contact (BIC=52% and 65%) compared to shot-blasted treated (SB) implants (BIC=46% and 47%) at weeks 4 and 8, respectively. However, bioactive charged implants produced by plasma (PL) or thermochemical (BIO) processes exhibited enhanced osteoconductivity through specific ionic surface-tissue exchange (PL, BIC= 69% and 77% and BIO, BIC= 85% and 87% at weeks 4 and 8 respectively). Furthermore, bioactive surfaces (PL and BIO) showed functional mechanical stability (resonance frequency analyses) as early as 4 weeks post implantation via increased total bone area (BAT=56% and 59%) ingrowth compared to SB (BAT=35%) and AE (BAT=35%) surfaces. info:eu-repo/semantics/acceptedVersion

Evaluate the quality of finishing and degree of contamination before and after handling and surface treatment of titanium (Ti) orthodontic mini-implants (OMIs). A scanning electron microscope (SEM) study on ninety-six titanium OMIs was done. Energy-Dispersive X-ray Analysis (EDX) identified the present particles on manufactured OMIs surfaces. Then, OMIs were manipulated with gauze (dry sterile, soaked in chlorhexidine) and gloves (latex, nitrile) to evaluate the contamination of these handling materials. Finally, OMIs underwent surface treatments and were placed in bone to observe the contaminants they released. Roughness (Ra) and wettability with contact angle parameter (CA) were measured on these treated OMIs. Machined OMIs presented surface irregularities and were contaminated with manufacturing-process particles (carbon, plastic Polyvinyl Chloride PVC, aluminum). Hand-manipulated OMIs were also contaminated by the handling materials. OMIs surface characteristics were as follows: acid-etched (Ra 1.3 m, CA 66 ), machined (Ra 0.3 m, CA 68 ), SB (Ra 3.3 m, CA 78 ), and SBAO (Ra 3.1 m, CA 92 ). Bone was contaminated by OMIs surface defects and extra particles. Manufactured OMIs have surface contaminants that increase with clinical handling. Surface treatments (SBAO, a combination of sandblasting and anodic oxidation) increase the roughness and contact angle, which play an important role in osseointegration. Surface-treated OMIs leave titanium particles in the bone during their insertion-removal. The use of a gauze soaked in chlorhexidine is recommended when handling OMIs. Further investigations would be interesting to study more variables and confirm the present results. Spanish Government and and European Union FEDER Generalitat de Cataluña

In this study, highly-interconnected porous titanium implants were produced by powder sintering with different porous diameters and open interconnectivity. The actual foams were produced using high cost technologies: Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD), and spark plasma sintering, and the porosity and/or interconnection was not optimized. The aim was to generate a bioactive surface on foams using two different strategies, based on inorganic thermo-chemical treatment and organic coating by peptide adsorption, to enhance osseointegration. Porosity was produced using NaCl as a space holder and polyethyleneglicol as a binder phase. Static and fatigue tests were performed in order to determine mechanical behaviors. Surface bioactivation was performed using a thermo-chemical treatment or by chemical adsorption with peptides. Osteoblast-like cells were cultured and cytotoxicity was measured. Bioactivated scaffolds and a control were implanted in the tibiae of rabbits. Histomorphometric evaluation was performed at 4 weeks after implantation. Interconnected porosity was 53% with an average diameter of 210 &micro, m and an elastic modulus of around 1 GPa with good mechanical properties. The samples presented cell survival values close to 100% of viability. Newly formed bone was observed inside macropores, through interconnected porosity, and on the implant surface. Successful bone colonization of inner structure (40%) suggested good osteoconductive capability of the implant. Bioactivated foams showed better results than non-treated ones, suggesting both bioactivation strategies induce osteointegration capability.

Las superficies de los implantes son un foco para la colonización de bacterias, ya sean externas, o se encuentren dentro del organismo. El problema reside en que pueden provocar infecciones severas, con consecuencias devastadoras para el organismo. La dificultad reside en que los implantes son zonas muy poco vascularizadas y tanto los antibióticos, como los antígenos del sistema inmune tienen muy difícil el acceso. Por ello se está estudiando que el propio implante ya lleve consigo propiedades antibacterianas. En concreto, en este proyecto se estudia que implantes de titanio puedan ir recubiertos de un film polimérico con algún principio activo incrustado, que provoque la inhibición de proliferación bacteriana sobre la superficie del implante. Este proyecto contempla la posibilidad de que creando multicapas se pueda ralentizar el proceso de difusión y por tanto, alargar el efecto antibacteriano. Como principios activos empleados para el estudio se ha seleccionado el Carvacrol, un aceite esencial con propiedades antibacterianas y la Doxiciclina, un antibiótico perteneciente al grupo de las tetraciclinas. De esta forma se estudia como varia el proceso de difusión y la caracterización de las superficies de las diferentes muestras dependiendo de las moléculas empleadas.

Treball Final de Grau d'Odontologia, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Curs: 2016-2017, Director: Gemma Sanmartí Garcia, Introducció: Estudi experimental preliminar, sobre el despreniment de partícules de titani (Ti) durant la col·locació i explantació d’implants dentals, sobre mostres cadavèriques d’origen humà. Objectius: L’objectiu principal de la investigació, és la determinació, mitjançant microscòpia òptica i electrònica, i l’anàlisi química microscòpica, de la presència o absència de partícules de Ti, exfoliades durant els processos d’inserció i/o explantació, d’implants dentals. Disseny de l’estudi: Es van col·locar 13 implants, sobre 4 mostres cadavèriques d’origen humà. Del total d’implants emprats, 5 van ser explantats posteriorment, per l’anàlisi microscòpica de les superfícies dels alvèols post-explantació; els 8 implants restants, van romandre a l’os, pel posterior estudi microscòpic de l’os periimplantari i l’os alveolar. Així mateix, la primera mostra cadavèrica estudiada, presentava 7 implants col·locats ante mortem. Resultats: L’anàlisi mitjançant el microscopi electrònic de rastreig Quanta X200, va permetre la detecció de partícules de Ti en 2 de les 5 mostres dels alvèols d’explantació estudiats, i de traces de Ti en 3 de les superfícies d’explantació analitzades, corresponents a les mostres 1, 4 i 11. Es va descartar una possible contaminació de les mostres dels alvèols post-explantació, a partir d’una anàlisi microscòpica i química del disc diamantat emprat en les seccions. Les mostres d’implantació van experimentar una contaminació de partícules de Ti, originada per les seccions efectuades amb serra de precisió i baixa velocitat. Tanmateix, no es van detectar partícules de Ti compatibles amb l’exfoliació de partícules de Ti durant la inserció dels implants, segons la forma i mida de les partícules localitzades en els alvèols d’explantació. L’observació de les mostres mitjançant microscòpia òptica no va proporcionar informació rellevant. Conclusions: S’han detectat partícules de Ti despreses en 2 de les 5 mostres d’explantació analitzades, però una major densitat òssia o una força elevada d’inserció dels implants, no han estat factors determinants en l’aparició de partícules de Ti. La detecció d’aquestes no comporta conseqüències significants a nivell clínic. Es requereixen nous estudis per a determinar l’origen de les partícules de Ti observades.

Producción Científica, The main clinical problems for dental implants are (1) formation of biofilm around the implant—a condition known as peri-implantitis and (2) inadequate bone formation around the implant—lack of osseointegration. Therefore, developing an implant to overcome these problems is of significant interest to the dental community. Chitosan has been reported to have good biocompatibility and anti-bacterial activity. An osseo-inductive recombinant elastin-like biopolymer (P-HAP), that contains a peptide derived from the protein statherin, has been reported to induce biomineralization and osteoblast differentiation. In this study, chitosan/P-HAP bi-layers were built on a titanium surface using a layer-by-layer (LbL) assembly technique. The difference in the water contact angle between consecutive layers, the representative peaks in diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), X-ray photoelectron spectroscopy (XPS), and the changes in the topography between surfaces with a different number of bi-layers observed using atomic force microscopy (AFM), all indicated the successful establishment of chitosan/P-HAP LbL assembly on the titanium surface. The LbL-modified surfaces showed increased biomineralization, an appropriate mouse pre-osteoblastic cell response, and significant anti-bacterial activity against Streptococcus gordonii, a primary colonizer of tissues in the oral environment, Ministerio de Economía, Industria y Competitividad (Project MAT2013-42473-R and MAT2015-68901R), Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA244U13, VA313U14 and VA015U16)

Three methods for the production of Polyethylene glycol (PEG) coatings on titanium are compared, i.e. plasma polymerization, electrodeposition and silanization. The compared deposition methods presented similar wettability (hydrophilic coatings), chemical composition assessed by XPS and thickness around 1 nm. The coatings lowered albumin adsorption and presented a decreased fibroblast, Streptococcus sanguinis and Lactobacillus salivarius adhesion. Immobilization of a cell adhesion peptide (RGD) presented a higher fibroblast adhesion and no alteration of the bacterial adhesion, giving three methods for the biofunctionalization of titanium for dental implants. The feasibility of each methodology is compared in terms of the process parameters in order to provide a guide for the election of the methodology. info:eu-repo/semantics/acceptedVersion

Objectives: The aim of this study was to determine the antibacterial properties of silver-doped titanium surfaces prepared with a novel electrochemical anodizing process. Material and methods: Titanium samples were anodized with a pulsed process in a solution of silver nitrate and sodium thiosulphate at room temperature with stirring. Samples were processed with different electrolyte concentrations and treatment cycles to improve silver deposition. Physicochemical properties were determined by X-ray photoelectron spectroscopy, contact angle measurements, white-light interferometry, and scanning electron microscopy. Cellular cytotoxicity in human fibroblasts was studied with lactate dehydrogenase assays. The in vitro effect of treated surfaces on two oral bacteria strains (Streptococcus sanguinis and Lactobacillus salivarius) was studied with viable bacterial adhesion measurements and growth curve assays. Nonparametric statistical Kruskal-Wallis and Mann-Whitney U-tests were used for multiple and paired comparisons, respectively. Post hoc Spearman's correlation tests were calculated to check the dependence between bacteria adhesion and surface properties. Results: X-ray photoelectron spectroscopy results confirmed the presence of silver on treated samples and showed that treatments with higher silver nitrate concentration and more cycles increased the silver deposition on titanium surface. No negative effects in fibroblast cell viability were detected and a significant reduction on bacterial adhesion in vitro was achieved in silver-treated samples compared with control titanium. Conclusions: Silver deposition on titanium with a novel electrochemical anodizing process produced surfaces with significant antibacterial properties in vitro without negative effects on cell viability. info:eu-repo/semantics/acceptedVersion

In this work, we analysed 56 clinically failed and retrieved implants by means of scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and histological studies. The surface contamination was compared to that of unused control implants and with that of the same implants after cleaning in a basic medium. The surfaces of the unused implants presented considerable contamination. In particular, high levels of carbon were detected. The nature of this C was elucidated by XPS analysis of the lubricant used in the machining process. The same contamination was observed in the retrieved implants. Histological studies were carried out by means of light microscopy. Fibrosis and granulomatous lesions were detected in the tissues. XPS analysis indicated the presence of traces of other elements (Na, Ca, Zn, S, F, etc.) that were not related to impurities in cpTi. We examined a cleaning process in a basic medium that eliminates the organic components of the implant surfaces. The cleaned implants were implanted in the patients and the results were excellent. None of the implants failed in following 7 months.

La presencia de malalties periodontals generalment comença amb la deposició d’una gran quantitat de colònies Bacterianes, que, conjuntament amb altres factors (com ferides, etc.) afecten a la salut buco dental. Les bactèries interactuen entre elles formant el Bio-film Bacterià que es transformarà en la placa Bacteriana. Aquesta última es la encarregada de danyar el teixit tou que protegeix les unions dentals i començar el procés d’una possible malaltia periodontal. Degut això el present projecte ha estudiat el comportament antibacterià d’un recobriment sobre la superfície de Titani (Ti), davant l’hipotètic cas d’una pèrdua dental i el seu procés de reemplaçament (implant). Per aquests motiu, la zona d’acció del recobriment que s’ha estudiat en aquests projecte, correspon a la zona de contacte entre el Ti i geniva. Les condicions estudiades han sigut, quitosà dopat amb nano partícules d’Argent i Carvacrol ( component actiu de la farigola), degut a la propietat antibacteriana de l’argent i a les respostes antibacterianes, antiinflamatòries del Carvacrol.

Tot i que actualment els implants dentals de titani tenen un baix percentatge de fallada, encara hi ha diverses causes que poden provocar dificultats. Dues de les causes més rellevants i comunes són la baixa velocitat d’osteointegració i la creació de film bacterià a la superfície de l’implant. Per tal de millorar aquestes dificultats s’ha demostrat que diferents pèptids com l’RGD, són capaços de millorar l’osteointegració i altres com la hLf1-11 reduir l’adhesió bacteriana. Fins a la data, aquestes dificultats s’han tractat de forma separada. Actualment, però, hi ha diverses investigacions que estudien poder combinar aquestes dues estratègies per poder resoldre els problemes de forma simultània. Una d’aquestes estratègies és l’adhesió sobre la superfície de titani d’una plataforma dual que contingui els pèptids que realitzen la funció desitjada. En el aquest projecte es vol, mitjançant diverses caracteritzacions físiques, químiques i biològiques de la superfície del titani, demostrar la funcionalitat d’una plataforma dual amb els pèptids RGD i hLf1-11.

Titanium dental implants are commonly used for the replacement of lost teeth, but they present a considerable number of failures due to the infection on surrounding tissues. The aim of this paper is the development of a polyethylene glycol-like (PEG-like) coating on the titanium surface by plasma polymerization to obtain a novel improved surface with suitable low bacterial adhesion and adequate cell response. Surface analysis data of these coatings are presented, in particular, water contact angle, surface roughness, and film chemistry, demonstrating the presence of a PEG-like coating. Streptococcus sanguinis and Lactobacillus salivarius bacterial adhesion assays showed a decreased adhesion on the plasma polymerized samples, while cell adhesion of fibroblasts and osteoblasts on the treated surfaces was similar to control surfaces. Thus, the PEG-like antifouling coating obtained by plasma polymerization on Ti confers this biomaterial's highly suitable properties for dental applications, as they reduce the possibility of infection while allowing the tissue integration around the implant. info:eu-repo/semantics/acceptedVersion

The present work is a revision of the processes occurring in osseointegration of titanium dental implants according to different types of surfaces -namely, polished surfaces, rough surfaces obtained from subtraction methods, as well as the new hydroxyapatite biomimetic surfaces obtained from thermochemical processes. Hydroxyapatite’s high plasma-projection temperatures have proven to prevent the formation of crystalline apatite on the titanium dental implant, but lead to the formation of amorphous calcium phosphate (i.e., with no crystal structure) instead. This layer produce some osseointegration yet the calcium phosphate layer will eventually dissolve and leave a gap between the bone and the dental implant, thus leading to osseointegration failure due to bacterial colonization. A new surface -recently obtained by thermochemical processes- produces, by crystallization, a layer of apatite with the same mineral content as human bone that is chemically bonded to the titanium surface. Osseointegration speed was tested by means of minipigs, showing bone formation after 3 to 4 weeks, with the security that a dental implant can be loaded. This surface can be an excellent candidate for immediate or early loading procedures. Key words:Dental implants, implants surfaces, osseointegration, biomimetics surfaces.

Dental implant failure can be associated with infections that develop into peri-implantitis. In order to reduce biofilm formation, several strategies focusing on the use of antimicrobial peptides (AMPs) have been studied. To covalently immobilize these molecules onto metallic substrates, several techniques have been developed, including silanization and polymer brush prepared by surface-initiated atom transfer radical polymerization (ATRP), with varied peptide binding yield and antibacterial performance. The aim of the present study was to compare the efficiency of these methods to immobilize the lactoferrin-derived hLf1–11 antibacterial peptide onto titanium, and evaluate their antibacterial activity in vitro. Smooth titanium samples were coated with hLf1–11 peptide under three different conditions: silanization with 3-aminopropyltriethoxysilane (APTES), and polymer brush based coatings with two different silanes. Peptide presence was determined by X-ray photoelectron spectroscopy, and the mechanical stability of the coatings was studied under ultrasonication. The LDH assays confirmed that HFFs viability and proliferation were no affected by the treatments. The in vitro antibacterial properties of the modified surfaces were tested with two oral strains (Streptococcus sanguinis and Lactobacillus salivarius) showing an outstanding reduction. A higher decrease in bacterial attachment was noticed when samples were modified by ATRP methods compared to silanization. This effect is likely due to the capacity to immobilize more peptide on the surfaces using polymer brushes and the nonfouling nature of polymer PDMA segment. info:eu-repo/semantics/acceptedVersion

L'ús d'implants dentals ha suposat un dels avenços més importants en la pràctica odontològica. Tot i això, no estan exempts de problemes. Un dels principals factors de risc és l'aparició d'infeccions bacterianes en el teixit periimplantari que condueixin a la pèrdua de l'implant. Per això, es busca minimitzar la formació de biofilms bacterians mitjançant recobriments antifouling. En aquest projecte s'han estudiat i realitzat tractaments antifouling de polietilenglicol (PEG) de la superfície de titani d'implants dentals mitjançant polimerització per plasma, electrodeposició i silanización. Cada tractament permet la unió del polímer PEG a la superfície de l'implant dental amb diferents característiques. A més, s'ha demostrat la capacitat de funcionalitzar aquests recobriments utilitzant el pèptid RGD. S'ha procedit a la caracterització fisicoquímica i biològica dels recobriments obtinguts. Per a això, s'han determinat la humectabilitat, la rugositat i la composició química superficial dels mateixos, així com el seu comportament enfront de l'adsorció de proteïnes, a l'adhesió cel·lular i l'adhesió de soques bacterianes presents al biofilm bucal. També s'ha realitzat un assaig de citotoxicitat cel·lular per determinar la seva biocompatibilitat. Finalment, s'ha determinat el tractament que presenta les millors característiques, considerant el processat aplicat i els resultats obtinguts.

Thrombosis and restenosis are the most common problems during insertion of biocompatible implants like titanium stents into human blood, due to aggregation of platelets on their surfaces. Because of this reason, we studied the response of blood platelets to a plasma treated titanium surface. The aim was to design a functionalized surface which would repel blood platelets or prevent their adhesion. Therefore, we functionalized surfaces with low-temperature inductively coupled oxygen plasma treatment, which in the first stage cleaned the surface of titanium, and in the second promoted incorporation of oxygen functional groups as well as the growth of a titanium dioxide film. In this paper we show that oxygen atoms or oxygen containing groups play an important role in the repulsion of platelets and their deactivation. At the same time, increased surface temperature of samples either through sequential thermal deactivation in oven at 150 °C or heating the surface with ion bombardment during the treatment, lowers the oxygen content and the surface repulsion for platelets.

Objectives The main purpose of this work was to assess the short-term bone regenerative potential of new osteoconductive implants. The novelty of the study lies in the analysis of the effectiveness of a novel two-step treatment which combines shot-blasting with a thermo-chemical treatment, at very short times after implant placement in a minipig model. Materials and methods Three hundred twenty implants with four different surface treatments, namely bioactivated sur- faces, micro-rough grit-blasted, micro-rough acid-etched and smooth as-machined titanium implants were placed into the bone of 20 minipigs. The percent of bone-to-implant contact was determined 3 days, 1, 2, 3 and 10 weeks after implant placement by histomorphometric analysis. Surface composition, topography and wettability of the implant specimens were analysed. Results The combination of shot-blasting and thermo- chemical treatment accelerated bone regeneration at early stages in comparison with all other treatments between day 3 and week 3 ( p

Dental implant failure is commonly associated to dental plaque formation. This problem starts with bacterial colonization on implant surface upon implantation. Early colonizers (such as Streptococcus sanguinis) play a key role on that process, because they attach directly to the surface and facilitate adhesion of later colonizers. Surface treatments have been focused to improve osseointegration, where shot-blasting is one of the most used. However the effects on bacterial adhesion on that sort of surfaces have not been elucidated at all. A methodological procedure to test bacterial adherence to titanium shot-blasted surfaces (alumina and silicon carbide) by quantifying bacterial detached cells per area unit, was performed. In parallel, the surface properties of samples (i.e., roughness and surface energy), were analyzed in order to assess the relationship between surface treatment and bacterial adhesion. Rather than roughness, surface energy correlated to physicochemical properties of shot-blasted particles appears as critical factors for S. sanguinis adherence to titanium surfaces.

Como es sabido la peri-implantitis presentan similitudes con la periodontitis, (tales como: infeccion localizada, movilidad y en el diagnostico radiologico una zona radiolucida como indicacion de perdida osea) y es generalmente descrita como una condicion inflamatoria de los tejidos alrededor de un implante dental (asociada comunmente a la presencia de bacterias). Dicha afeccion inicia con la destruccion de los tejidos blandos y puede continuar hasta la destruccion del hueso periimplantar. [1], [2] De igual forma que la superficie del diente provee las condiciones necesarias para la colonizacion microbiana, la superficie del aditamento transmucoso de los implantes dentales se ve afectado por la misma causa. El papel que juegan las bacterias en enfermedades propias de la boca (caries, y enfermedad periodontal), ha llevado a varios investigadores a tratar de aislar e identificar las bacterias asociadas a cada uno de los padecimientos, por ejemplo Wade y colaboradores [3], realizaron cultivos de la flora bacteriana de diversas enfermedades bucales como lo son la caries, infecciones endodonticas y periodontitis. De esto aislaron 3592 clones clasificados en especie, de los cuales 62 fueron encontrados en las muestras de endodoncia, 98 en las lesiones cariosas mientras que las muestras periodontales mostraron la mas amplia gama de especies con 161. Y a su vez se encontro que 15 estaban asociadas tanto a caries como a infecciones endodonticas, 17 a caries y enfermedad periodontal y 21 a enfermedad periodontal e infecciones endodonticas. De las bacterias asociadas a enfermedad periodontal las mas comunes en diferentes estadios de dicho padecimiento fueron: Porphyromonas gingivalis y Actinobacillus actinomycetemcomitans. [4], [5], [6], [7], [8]. Pero estas bacterias por si solas no colonizan superficies, es decir necesitan de colonizadores primarios que proporcionen una superficie adecuada para su posterior colonizacion. Es sabido que S. sanguinis es una de las bacterias pioneras en la formacion del biofilm o pelicula adquirida, tambien conocida como colonizador primario [9].

[spa] Este trabajo evalúa el comportamiento electroquímico entre el Titanio CP (t), Ia aleación de Titanio Ti-6AI-4V (LT) y siete aleaciones dentales: dos aleaciones de Cromo-Cobalto de las marcas comerciales Remanium® 2000+ (R) y Wironite®extrahart, 4 aleaciones nobles de las marcas Cerapall®2 (C), Pontor2 (P), V-Gnathos® Plus (VG) y Pagalin 2 (PA) y una aleación para amalgama de Ia marca Dispersalloy (A). Las técnicas experimentales utilizadas incluyeron monitorización del potencial de circuito abierto y medidas de variación de Ia corriente galvánica por periodos de 24 horas, para los pares constituidos con cada una de las siete aleaciones presentadas por T y LT. Los estudios se realizaron in vitro, utilizando como electrólito una composición de saliva artificial diferente a las habitualmente utilizadas (279,280), estudiada y presentada por sus autores como Ia más adecuada para el estudio in vitro del comportamiento corrosivo de aleaciones destinadas a Ia confección de dispositivos de rehabilitación intraoral. Ademas de Ia diferencia en Ia composición, Ia saliva artificial fue usada siempre en situación de desaireación, con ello se pretendía simular situaciones cuya frecuencia en Ia cavidad oral no es irrelevante (35, 63, 135,281) Las muestras fueron analizadas mediante a SEM y su composición evaluada por EDS. Tras los tests efectuados, y en relación a Ia determinación de los valores de potencial de circuito abierto, nos es permitido afirmar que, en regia general, los diferentes metales pueden ser agrupados en función de las semejanzas de comportamiento. La aleación para amalgama, Dispersalloy® y Wironite ®extrahart presentan valor de potencial más negativo, manteniéndose así a lo largo de las 24 horas. De los restantes materiales, hemos agrupado el Titanio Puro con las aleaciones de Pagalin y Pontor, con valores de potencial de electrodo al finalizar las próximas 24 horas entre - 0,281 y - 0,287, a continuación con Ia aleación de Cromo Cobalto Remanium®Pius (-0,177) y, por último, con Ia aleación Cerapal®2, V-Gnathos®Pius y Ti-6AI-4V (con valores entre- 0,058 y +0, 015). Posteriormente a Ia evaluación de Ia corriente galvánica entre pares, verifica igualmente que hay un patrón de semejanza traducido por Ia variación de comportamiento de las diferentes aleaciones conforme el par sea T o LT, apareciendo más reactivas en presencia de LT, con excepcion de Ia aleación V-Gnathus, cuyos valores de corriente galvánica durante las 24 horas son más altos en el par con T La aleación para amalgama presenta valores de corriente galvánica que Ia contraindican en situaciones de proximidad con estructuras implantarias o supra implantarias de T o LT, valores los cuales son, también aquí, más elevados en presencia de LT. Sobre las aleaciones nobles Pontor2, Pagalin2 y Gnathus®Pius, concluimos que pueden ser recomendadas para estructuras supra implantarias, los dos primeras para lmplantes de Titanio y Ia última también para implantes de Ti- 6 AI-4V De todas las aleaciones no nobles testadas, Ia que presenta mejor comportamiento corrosivo es Remanium ®2000 + No se encontraron diferencias significativas entre nuestros resultados y los de otros autores que utilizaron saliva desaireada., [eng] Our work evaluated the electrochemical behaviour between Titanium CP (T), Titanium alloy Ti6A14V (LT) and 7 dental alloys: 2 chrome cobalt- Remanium 2000 (R) and Remanium GM 380 (RG); 4 noble alloys - Cerapall (C), Pontor (P), V-Gnathos Plus (VG) and Pagalin 2 (PA); and an amalgam alloy - Dispersalloy (A). The experimental techniques included open circuit potential monitoring and measurements of the galvanic current changes for 24 hour periods of the pairs of each of the 7 alloys and Tor LT. The experiments were conducted in vitro using as electrolyte modified artificial saliva, different from the standard that is thought to be the most adequate for the in vitro study of the corrosion of alloys used in intraoral rehabilitation devices... Artificial saliva was always used non aerated, trying to simulate in vivo frequent conditions... The samples were observed with SEM and its composition by EDS. After the tests, relating to the open circuit potential, we can state that the different metals can be grouped by similar behaviour. The amalgam alloy, Dispersalloy® and Wironite®extrahart presents the most negative potential value during the 24 hours. Pagalin can be grouped with Pontor, with similar electrode potential values after 24 hours (-0.281 to -0.287), the chrome cobalt Remanium®2000+ with -0.1777 and, finally Cerapall, V-Gnathos and Titanium alloy with values ranging from - 0.058 to 0.15. Concerning the galvanic current evaluations between pairs, there is also a similar pattern in the variation of behaviour of the different alloys when the pair is T or LT, being more reactive with the LT, except for V-Gnathus®Pius, in which case, the galvanic current values, during the 24 hours, are higher with T. The amalgam alloy presents galvanic current values that do not make it suitable to be used with Tor LT structures, being worst with LT. In what concerns the noble alloys Pontor2, Pagalin2 and V-Gnathos®Pius, we conclude that Pontor 2 and Pagalin2 can be used in Titania type structures and V-Gnathus®Pius is more suitable on Ti-6AI-4V structures Of all not noble tested alloys, the ones that show better corrosive behaviour are the chrome cobalt- Remanium® 2000 + Our results are comparable to others in which artificial saliva was aerated. After the galvanic current tests between pairs, the SEM analysis showed localized or generalized alterations on the surface of the sample, fact that never occurred with T or LT.

Se ha obtenido una capa de fosfato de calcio del mismo contenido mineral que el hueso en la superficie del implante dental de titanio, que tiene como consecuencia una muy rápida y eficaz osteointegración. Esta capa se ha obtenido mediante un método biomimético por vía termoquímica. La capa se une al substrato por enlace químico. Este hecho evita todos los inconvenientes de los métodos de recubrimiento convencionales (plasma spray, ablación láser...) cuya unión es por interacción mecánica, lo cual provocaba que hubiese espacio vacío entre el substrato y la capa facilitando la colonización bacteriana (periimplantitis) y un desprendimiento y degradación acelerados de la misma. Con la formación de la capa por el método termoquímico, sobre la superficie rugosa del implante, el tiempo de convalecencia se reduce significativamente ya que colocamos una estructura en la superficie del implante que las células reconocen, facilitando el crecimiento óseo alrededor del implante dental. A esta capacidad de formar capas cerámicas de fosfato de calcio en la superficie del biomaterial se la conoce como bioactividad y, anteriormente, era una habilidad que sólo tenían algunas cerámicas y vidrios. El desarrollo y obtención de estos implantes de titanio con una rugosidad optimizada y bioactivos combina una magnífica fijación mecánica con la rapidez del crecimiento del hueso, con lo que se consigue un implante con mejor osteointegración tanto a corto como a largo plazo.

This study examined the roughness and bonding strength of the chemical-made apatite layer in comparison with the titanium surface and the plasma-sprayed apatite. Commercially pure titanium plates were heated and chemically treated to deposit crystalline apatite on their surface. The roughness of the titanium surface of the original samples and the apatite surface was analyzed by a roughness surface tester. A scratch test was used to compare the adhesion of the chemical apatite layer to the titanium with the adhesion of a plasma-sprayed layer. A dense bone-like apatite layer was formed on the surface of the titanium by a simple chemical method. The surface roughness test showed that the chemical apatite coating increased the roughness of the samples. The scratch test showed that the bonding strength of the chemical-made apatite coatings to the titanium substrate was higher than the plasma-sprayed apatite coatings. The apatite layer produced by chemical treatment did not show a lower roughness than the titanium substrate. This chemical apatite layer also bonded tighter to the titanium than the plasma-sprayed apatite. This chemically made apatite coating is expected to provide a long-term implant-bone fixation.

El aumento de tratamientos prostodónticos implantosoportados para restituir la perdida de dientes supone que la cirugía de implantes sea una actividad habitual en las clínicas odontológicas, por ello la operación de colocación de los implantes debe garantizar el éxito teniendo en cuenta unas recomendaciones importantes entre las que destaca evitar el calentamiento excesivo del hueso durante la perforación del lecho óseo que puede provocar desnaturalización de proteínas y necrosis ósea.También es necesaria la máxima biocompatibilidad en la prótesis ha realizar sobre los implantes de titanio debido a la corrosión galvánica que existe por el contacto de metales de distinta naturaleza dentro de un medio conductor como es la saliva, para evitar esto se usa titanio como metal para prótesis, pero existen dificultades de manipulación y de unión con la cerámica que dificultan su aceptación clínica generalizada.El primer tema de investigación fue el estudio in vitro del control de la temperatura del hueso durante el fresado del lecho óseo. Se fabricaron tres fantomas para valorar las diferencias que pueden existir entre diversos sistemas impulsión de suero fisiológico y de irrigación del lecho óseo en función del diseño de las fresas. Se observó que las condiciones en que el suero fisiológico va desde la botella hasta la zona quirúrgica influyen en su calentamiento, encontrando diferencias estadísticamente significativas entre las bombas de impulsión usadas, no se encontraron diferencias estadísticamente significativas entre fresas cortas y largas con irrigación interna cerca de la punta de la fresa. También se valoró in vitro la eficacia de tres sistemas de irrigación (externa, interna en la base de fresa e interna en la punta de la fresa) para hacer llegar un volumen de suero adecuado en el fondo del lecho fresado y su influencia en la evolución de la temperatura del hueso fresado. Se observó que la irrigación interna cerca de la punta de la fresa obtuvo los mejores resultados con diferencias estadísticamente significativas respecto los otros sistemas de refrigeración.El segundo tema de investigación fue valorar la adhesión entre las estructuras protésicas fabricadas en diversos tipos de titanio y algunas cerámicas cocidas sobre él, mediante ensayos mecánicos de flexión en tres puntos. Un estudio preliminar permitió valorar si las diferencias entre el titanio grado 2 y el grado 4, que tienen propiedades mecánicas y químicas distintas, podían influir en la unión con las cerámicas y en su comportamiento mecánico. A partir de los resultados se definió el grado de titanio y el tratamiento superficial que optimiza la adhesión con las cerámicas para realizar un segundo estudio de comparación entre titanio colado y mecanizado. Para el estudio preliminar se fabricaron unos modelos de simulación con distintas combinaciones de titanio y cerámicas, que se ensayaron mecánicamente y se observaron con microscopio electrónico para analizar las fracturas. En este estudio obtuvo mejores resultados de resistencia a la flexión la combinación de titanio grado 4 y cerámica, pero se observó que era mejor la adhesión entre el titanio grado 2 y la cerámica debido a la mayor micro-rugosidad superficial del titanio grado 2.La comparación entre titanio colado y mecanizado se realizó de acuerdo a la Norma Europea EN ISO 9693:1999 publicada en español en septiembre de 2.000. Se usaron combinaciones de Cr-Ni y Cr-Co con cerámica a modo de control negativo.Los valores de resistencia a flexión del titanio colado y mecanizado no presentaron diferencias estadísticamente significativas entre ellos, además superaron ampliamente los mínimos exigidos para la aplicación clínica de una combinación de materiales.

El objetivo de este trabajo de investigación es la obtención de una capa de anodizado, que sea homogénea en toda la superficie del implante de titanio. Esta capa de óxido de titanio tendrá unas propiedades beneficiosas para el implante dental como son: 1. Limpieza de residuos tanto orgánicos como inorgánicos de la superficie del implante. 2. Mejora de la resistencia a la corrosión del implante. 3. Disminución de la liberación de iones del titanio al medio fisiológico. 4. Aumento de la dureza superficial así como de la resistencia al desgaste.

Los diversos implantes de titanio, aunque basados todos ellos en los mismos principios de osteointegración, varían significativamente en su diseño, técnica quirúrgica de implantación, sistema de retención en el hueso, características químicas y mecánicas de su superficie. Desarrollamos, desde la perspectiva de la ciencia de los materiales, una exposición comparativa de los sistemas de implantes de mayor uso clínico en la actualidad, analizando los factores dependientes de sus biomateriales (diseño macroscópico, topografía de superficie, resistencia a la corrosión, química de superficie, recubrimientos superficiales), de su comportamiento biomecánico (propiedades mecánicas, relación volumen/superficie), y la repercusión de estos factores sobre las características biológicas de las interfases implanto-tisulares.

En el present Treball de Final de Grau es fa un estudi d’una possible tècnica de millora de la integració dels implants dentals de titani amb el teixit cel·lular, i tracta específicament l’opció de crear una superfície de titani el més antibacteriana possible. Mitjançant un atac de caràcter àcid, la superfície del titani queda modificada creant una nanoestructura que segons l’article Surface Nanoporosity has a greater influence on osteogènic and bacterial cell adhesion than crystallinity and wettability [1] esdevé antibacteriana. Així doncs, l’objectiu del projecte és replicar aquesta superfície que per si sola és antibacteriana i a més a més, tal com diu l’altre article Anhydride-functional silane immobilized onto titanium surfaces induces osteoblasts cell differentiation and reduces bacterial adhesion and biofilm formation [2], afegir un silà anomenat TESPSA que també té un efecte antibacterià; de forma que amb la combinació d’ambdós efectes, poder obtenir una superfície del titani idònia, pel seu caràcter antibacterià, pels implants dentals. Com a objectiu extra del projecte, s’intenta, també, optimitzar el temps de producció de la superfície de titani creada segons el primer dels articles [1]. Per a dur a terme aquest projecte cal un treball de laboratori que consta en la preparació de mostres de titani llises, fer sobre elles un atac àcid amb una solució anomenada Piranha, silanitzar les mostres amb TESPSA, fer una caracterització de la superfície atacada i finalment, realitzar assaigs amb bacteris amb l’objectiu de verificar si es tracta d’una superfície antibacteriana o no. A l’hora de procedir amb aquest treball de laboratori, s’ha pogut fer tot el proposat, tot i que els resultats d’alguns assajos no han estat els esperats. L’intent de rèplica de la superfície del titani de l’article de Rodriguez-Contreras, et al. 2018 [1], no ha resultat en la superfície antibacteriana esperada. De totes formes, s’ha procedit amb el projecte usant una variant de superfície que es va extreure a partir d’una variació en l’atac amb Piranha, per verificar l’efectivitat antibacteriana del TESPSA.

Titanium dental implants are commonly used for the replacement of lost teeth, but they present a considerable number of failures due to the infection on surrounding tissues. The aim of this paper is the development of a polyethylene glycol-like (PEG-like) coating on the titanium surface by plasma polymerization to obtain a novel improved surface with suitable low bacterial adhesion and adequate cell response. Surface analysis data of these coatings are presented, in particular, water contact angle, surface roughness, and film chemistry, demonstrating the presence of a PEG-like coating. Streptococcus sanguinis and Lactobacillus salivarius bacterial adhesion assays showed a decreased adhesion on the plasma polymerized samples, while cell adhesion of fibroblasts and osteoblasts on the treated surfaces was similar to control surfaces. Thus, the PEG-like antifouling coating obtained by plasma polymerization on Ti confers this biomaterial's highly suitable properties for dental applications, as they reduce the possibility of infection while allowing the tissue integration around the implant. (C) 2015 American Vacuum Society.

This study shows the potential risk of microfiltration between two different types of implant-abutment connections screwed at 45 Ncm: external and internal. For the first time the use of a mechanical artificial mouth is used with the values (compression and torsion loads with a frequency of 2 Hz) of the human chewing. The mechanical tests were performed with an artificial saliva at 37 degrees C. The microgap in the connection was measured by an Image Analysis software incorporated in a high resolution scanning electron microscopy. Implant connections were filled with methylene blue by using self-adjustable precision pipettes and the quantity of leakage was determined by high sensitivity spectometry. We showed that the internal connection has lower microgaps compared to the external ones and these microgaps increased with the number of mechanical cycles. The leakage of methylene blue was higher when the external connection was performed. Microgaps and the influence of the mechanical loads are very important for the long-term behavior avoiding the bacteria colonization in the dental implants. These aspects should be known by the implantologists. info:eu-repo/semantics/acceptedVersion