Bioeutectic® ceramics for biomedical application obtained by laser floating zone method. In vivo evaluation

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license.In this study, the Bioeutectic® blocks were inserted into the critical size defects of eight rabbits, using both tibiae, and the physical and chemical nature of the remodeled interface between the Bioeutectic® implants and the surrounding bone were performed at four and 15 months. The results showed a new fully mineralized bone growing in direct contact with the implants. The ionic exchange, taking place at the implant interface with the body fluids was essential in the process of the implant integration through a dissolution-precipitation-transformation mechanism. The study found the interface biologically and chemically active over the 15 months implantation period. The osteoblastic cells migrated towards the interface and colonized the surface at the contact areas with the bone. The new developed apatite structure of porous morphology mimics natural bone. © 2014 by the authors.The authors wish to acknowledge funding from the European Community at the 7th Framework Program EU No. 314630-UV Marking and Generalitat Valenciana (GVA) within the Project ACOMP/2009/173.Peer Reviewe

Microgrooves and microrugosities in titanium implant surfaces: an in vitro and in vivo evaluation

This article belongs to the Special Issue Clinical Implants and the Biocompatibility of Biodegradable BiomaterialsThe physical characteristics of an implant surface can determine and/or facilitate osseointegration processes. In this sense, a new implant surface with microgrooves associated with plus double acid treatment to generate roughness was evaluated and compared in vitro and in vivo with a non-treated (smooth) and double acid surface treatment. Thirty disks and thirty-six conical implants manufactured from commercially pure titanium (grade IV) were prepared for this study. Three groups were determined, as described below: Group 1 (G1), where the samples were only machined; group 2 (G2), where the samples were machined and had their surface treated to generate roughness; and test group 3 (G3), where the samples were machined with microgrooves and the surface was treated to generate the roughness. For the in vitro analysis, the samples were submitted to scanning microscopy (SEM), surface profilometry, the atomic force microscope (MFA) and the surface energy test. For the in vivo analyses, thirty-six implants were placed in the tibia of 9 New Zealand rabbits in a randomized manner, after histological and histomorphometric analysis, to determine the level of contact between the bone and implant (BIC%) and the bone area fraction occupancy (BAFO%) inside of the threads. The data collected were statistically analyzed between groups (p < 0.05). The in vitro evaluations showed different roughness patterns between the groups, and the G3 group had the highest values. In vivo evaluations of the BIC% showed 50.45 ± 9.57% for the G1 group, 55.32 ± 10.31% for the G2 group and 68.65 ± 9.98% for the G3 group, with significant statistical difference between the groups (p < 0.0001). In the BAFO% values, the G1 group presented 54.97 ± 9.56%, the G2 group 59.09 ± 10.13% and the G3 group 70.12 ± 11.07%, with statistical difference between the groups (p < 0.001). The results obtained in the evaluations show that the surface with microgrooves stimulates the process of osseointegration, accelerating the healing process, increasing the contact between the bone and the implant and the area of new bone formation

Materiales biocerámicos cristalinos

[EN] A strong interest in the use of ceramics for biomedical engineering applications developed in the late 1960´s. Used initially as alternatives to metallic materials in order to increase the biocompatibility of implants, bioceramics have become a diverse class of biomaterials, presently including three basic types: relatively bioinert ceramics; bioactive or surface reactive bioceramics and bioresorbable ceramics. This review will only refer to bioceramics “sensus stricto”, it is to say, those ceramic materials constituted for nonmetallic inorganic compounds, crystallines and consolidated by thermal treatments of powders to high temperatures. Leaving bioglasses, glass-ceramics and biocements apart, since, although all of them are obtained by thermal treatments to high temperatures, the first are amorphous, the second are obtained by desvitrification of a glass and in them vitreous phase normally prevails on the crystalline phases and the third are consolidated by means of a hydraulic or chemical reaction to room temperature. A review of the composition, physiochemical properties and biological behaviour of the principal types of crystalline bioceramics is given, based on the literature data and on the own experience of the authors.[ES] A finales de los años sesenta se despertó un gran interés por el uso de los materiales cerámicos para aplicaciones biomédicas. Inicialmente utilizados como una alternativa a los materiales metálicos, con el propósito de incrementar la biocompatibilidad de los implantes, las biocerámicas se han convertido en una clase diversa de biomateriales, incluyendo actualmente tres tipos: cerámicas cuasi inertes; cerámicas bioactivas o reactivas superficialmente y cerámicas reabsorbibles o biodegradables. En la presente revisión se hace referencia a las biocerámicas en sentido estricto, es decir, a aquellos materiales constitutitos por compuestos inorgánicos no metálicos, cristalinos y consolidados mediante tratamientos térmicos a altas temperaturas. Dejando aparte los biovidrios, los vitrocerámicos y los biocementos, puesto que, si bien todos ellos son obtenidos por tratamiento térmicos a altas temperaturas, los primeros son amorfos, los segundos son obtenidos por desvitrificación de un vidrio, prevaleciendo normalmente la fase vítrea sobre las fases cristalinas, y los terceros son consolidados mediante una reacción química o hidráulica a temperatura ambiente. Así pues, teniendo en cuenta la abundante bibliografía sobre el tema y la experiencia propia de los autores, se presenta una revisión de la composición, propiedades fisicoquímicas, aplicaciones y comportamiento biológico de los principales tipos de biocerámicas cristalinas.The authors thank to CICYT the financial support of the Project MAT2003-08331-C02-01-02.Peer reviewe

Vidrios y Vitrocerámicos Bioactivos

[EN] Since the late 1960´s, a great interest in the use of bioceramic materials for biomedical applications has been developed. In a previous paper, the authors reviewed crystalline bioceramic materials "sensus stricto", it is to say, those ceramic materials, constituted for non-metallic inorganic compounds, crystallines and consolidates by thermal treatment of powders at high temperature. In the present review, the authors deal with those called bioactive glasses and glassceramics. Although all of them are also obtained by thermal treatment at high temperature, the first are amorphous and the second are obtained by devitrification of a glass, although the vitreous phase normally prevails on the crystalline phases. After an introduction to the concept of bioactive materials, a short historical review of the bioactive glasses development is made. Its preparation, reactivity in physiological media, mechanism of bonding to living tissues and mechanical strength of the bone-implant interface is also reported. Next, the concept of glass-ceramic and the way of its preparation are exposed. The composition, physicochemical properties and biological behaviour of the principal types of bioactive glasses and glass-ceramic materials: Bioglass®, Ceravital®, Cerabone®, Ilmaplant® and Bioverit® are also reviewed. Finally, a short review on the bioactive-glass coatings and bioactive-composites and most common uses of bioactive-glasses and glass-ceramics are carried out too.[ES] Desde finales de los años sesenta, se ha despertado un gran interés por el uso de los materiales biocerámicos para aplicaciones biomédicas. En un trabajo previo, los autores hicieron una revisión de los denominados materiales biocerámicos cristalinos en sentido estricto, es decir, de aquellos materiales, constituidos por compuestos inorgánicos no metálicos, cristalinos y consolidados mediante tratamientos térmicos a altas temperaturas. En el presente trabajo, los autores revisan el desarrollo de los vidrios bioactivos (biovidrios) y de las vitrocerámicas bioactivas. Si bien todos ellos son obtenidos también por tratamiento térmico a altas temperaturas, los primeros son amorfos y los segundos son obtenidos por desvitrificación de un vidrio, si bien la fase vítrea normalmente predomina sobre las fases cristalinas. Después de una introducción al concepto de material bioactivo, se expone una breve revisión histórica del desarrollo de los vidrios bioactivos. A continuación se describe su obtención, reactividad en suero fisiológico artificial, mecanismo de unión al tejido vivo y resistencia mecánica de la interfaz hueso-implante. Posteriormente, se expone el concepto de material vitrocerámico y el proceso de su obtención así como también se describen los principales tipos de vidrios y vitrocerámicos bioactivos (Bioglass®, Ceravital®, Cerabone®, Ilmaplant® and Bioverit®), sus composiciones, sus propiedades físico-químicas y sus comportamientos biológicos. Finalmente, se lleva a cabo también una corta revisión de los recubrimientos con vidrios bioactivos y de los materiales compuestos (composites) bioactivos así como de los usos más comunes de los vidrios y vitrocerámicos bioactivos.The authors wish to acknowledge funding from Spain’s CICYT within the framework of Projects MAT2003-08331-C02-01-02 and MAT2006-12749-C02-01-02 and Generalitat Valenciana (GVA) ACOMP06/044.Peer reviewe

Main Contributions to Bioceramics by Salvador De Aza

A full compilation of Salvador De Aza works on biomedical materials is a huge task beyond the aim of this paper; instead it is intended to stand out De Aza’s thoughts and leadership in the field of Bioceramics and to pay tribute to his memory. The most outstanding works of Professor Salvador De Aza related to Bioceramics, from the point of view of the authors, are commented and discussed. Topics the authors chose among many other De Aza’s works on biomedical materials are: The prediction and demonstration of bioactivity in pseudo-wollastonite ceramics; the use of phase diagrams to design bulk-bioactive ceramics with eutectic microstructures; the relationship between bioactivity and microstructure in ceramic biomaterials; and the studies on the polymorphic phase transitions in tricalcium phosphate.Peer reviewe

Dental cements from polyacrilic acid and wollastonite

[ES] Los cementos de polialcanoatos o iomómeros de vidrio son materiales que han sido utilizados con éxito durante más de 20 años en trabajos de odontología. Un problema que presentan dichos cementos es la liberación de iones Al3+ al medio fisiológico, lo que puede dar lugar a daños irreversibles en los pacientes. Con el propósito de evitar dicha liberación, se han preparado y caracterizado cementos obtenidos a partir de la reacción entre el ácido poliacrílico y la wollastonita (CaSiO3) en una solución acuosa de ácido tartárico. Los resultados obtenidos han puesto de manifiesto que estos cementos alcanzan resistencias a la compresión similares a las de los cementos de polialcanoato o ionómeros convencionales. Adicionalmente, los cementos resultantes son biocompatibles y bioactivos.[EN] The glass ionomer cements have been used successfully in dentistry for more than 20 years. A problem of these cements is the release of Al3+ ions to the physiological medium, being able to cause irreversible health problems to the patients. With the purpose of avoiding this problem, cements, from the reaction between the polyacrylic acid and wollastonita (CaSiO3) in a water solution of tartaric acid, have been obtained and characterized. The results have shown that these cements reach compression strength values similar to those of the conventional cements of vitreous polyalqueonate. Additionally, the obtained cements are biocompatibles and bioactives.Este trabajo ha sido financiado parcialmente por CICYTMAT - 2003 - 08331 - C02 - 01 - 02.Peer reviewe

Influence of Sterilization Techniques on the In Vitro Bioactivity of Pseudowollastonite

The purpose of this study was to investigate the effect of four sterilization methods (Steam autoclave, Hydrogen peroxide plasma, Ethylene oxide, and Gamma sterilization) on the surface chemistry and in vitro bioactivity of polycrystalline pseudowollastonite (psW). psW samples obtained by solid-state reaction sintering were sterilized and soaked in Kokubo et al.’s proposed simulated body fluid (SBF) up to 30 days. The sterilization procedure was found to result in no significant chemical changes in the surface of the samples. On the other hand, a Ca/P layer, of different thickness, identified as hydroxyapatite (HA) like, was developed on all the samples after soaking, although the Ethylene oxide-sterilized samples present a non-homogeneous and B68% thinner HA layer. The psW samples before soaking were analyzed by X-ray diffraction, raman spectroscopy, and scanning electron microscopy (SEM). The interfacial reaction product was examined by SEM fitted with an energy-dispersive X-ray analyzer. Additionally, changes in ionic concentrations at the psW/SBF interface were measuredPeer reviewe

Preparation, characterization and in vitro behavior of a new eutectoidbioceramic.

2014AbstractA new type of bioceramic has been designed and obtained within the sub-system Ca2SiO4–7CaOP2O52SiO2. The selected composition wasthat corresponding to the eutectoid point 69 wt% dicalcium silicate–31 wt% tricalcium phosphate. Sintering behavior, phase evolution andmicrostructural changes were analyzed by XRD and SEM. Bio-reactivity was determined by immersion of materials in simulated body fluid forseveral periods of time as well as studies in human adipose stem cells (hASC). The investigated materials are bio-acceptable since no toxic or otherharmful evidence was detected. A carbonated hydroxyapatite was formed on the surface of the 31R material within 3 days. Cell attachment assayshowed that the ceramics supported the hASC cells adhesion and spreading, and the cells established close contacts with the ceramics after 24 h ofculture. The influence of the microstructure (porosity, grain size and phase composition) on the in vitro behavior of the obtained bioceramics wasalso examined

In Situ Bone-Like Apatite Formation From a Bioeutectic SBF Dynamic Flow

In a previous study, a new ceramic material (Bioeutectic s ), prepared by slow solidification through the eutectic temperaturecomposition region of the wollastonite–tricalcium phosphate system, was found to be bioactive in static-simulated body fluid. The eutectic material reacts by dissolving the pseudowollastonite phase and forming a hydroxyapatite-like porous structure by a pseudomorphic transformation of the tricalcium phosphate lamellae, which in turn mimics porous bone. Later, a hydroxyapatite- like layer is formed by precipitation on the surface of the material. In the present study, the bioactivity of the Bioeutectic s material was assessed in dynamic simulated body fluid in order to improve the ingrowth of new bone into implants (osteointegration). Samples of the material were soaked for 2 weeks in a dynamic simulated body fluid (1 mL/min) at 371C. The experiment showed that there is no precipitation of hydroxyapatitelike layer on the surface of a the material. Otherwise, a complete transformation of the eutectic material takes place, giving rise to a hydroxyapatite artificial porous bone. The dynamic model used in this study may be better than the usual static immersion model in imitating the physiological condition of bone-like apatite formation.Peer reviewe

Human mesenchymalstemcellviability,proliferationanddifferentiation potential inresponsetoceramicchemistryandsurfaceroughness

We investigatedtheeffectoftheceramicchemistryandsurfaceroughnessofpure α-tricalcium phosphate,andalso αTCP dopedwitheither 1.5 wt%or3.0wt%ofdicalciumsilicate(C2S), ontheresponseofadulthumanmesenchymalstemcells(ahMSCs). AhMSCs wereplatedonto ceramic discs,preparedbyasolid-statereaction.Afterbeingsintered,somesampleswerepolishedupto1 μm, whileotherswerekeptas manufactured, whichresultedintwosurfaceroughnessgrades.Viability,proliferationandosteoinductivecapacityweredeterminedfollowing various incubationperiods. The resultsshowedanon-cytotoxiceffectafteranindirectapoptosistest.Celladhesionandproliferationweresurfaceroughness-sensitiveand increased proportionallytotheroughnessofmaterials.Theseobservationsbecamemoreevidentintheunpolished αTCP ceramicdopedwith 1.5 wt%C2S, whichinducedosteoblasticdifferentiationasaresultoftheroughnessandincreasedconcentrationoftheC2S solidsolution in αTCP