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Porous Oxide (porous + oxide)

Distribution by Scientific Domains
Medical Sciences80%

Kinds of Porous Oxide

  • titanium porous oxide
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    Selected Abstracts

    Si/SiO2 nanocomposite by CVD infiltration of porous SiO2

    PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2005
    G. Amato
    Abstract The aim of the present paper is to report first results on an innovative method for producing Si/SiO2 nanocomposites. Starting from a porous oxide structure, we infiltrated Si by Chemical Vapour Deposition of SiH4, under controlled conditions. In this way, we succeeded in infiltrating Si into the SiO2 template. Porous oxide is obtained by dry oxidation of mesoporous Si. By means of the electrochemical process used for producing porous Si, an interconnected pore structure is obtained. This allows for Si infiltration, giving rise, in principle, to an interconnected network of Si crystallites, in which electrical carriers are easily driven. Efficient charge injection in Si nanocrystals is of crucial importance for several applications, from electroluminescence to memory devices. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Bone formation at recombinant human bone morphogenetic protein-2-coated titanium implants in the posterior maxilla (Type IV bone) in non-human primates

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2008
    Ulf M. E. Wikesjö
    Abstract Background: Studies using ectopic rodent and orthotopic canine models (Type II bone) have shown that titanium porous oxide (TPO) surface implants adsorbed with recombinant human bone morphogenetic protein-2 (rhBMP-2) induce local bone formation including osseointegration. The objective of this study was to evaluate local bone formation and osseointegration at such implants placed into Type IV bone. Material and Methods: rhBMP-2-coated implants were installed into the edentulated posterior maxilla in eight young adult Cynomolgus monkeys: four animals each received three TPO implants adsorbed with rhBMP-2 (2.0 mg/ml) and four animals each received three TPO implants adsorbed with rhBMP-2 (0.2 mg/ml). Contra-lateral jaw quadrants received three TPO implants without rhBMP-2 (control). Treatments were alternated between left and right jaw quadrants. Mucosal flaps were advanced and sutured to submerge the implants. The animals received fluorescent bone markers at weeks 2, 3, 4, and at week 16 when they were euthanized for histologic analysis. Results: Clinical healing was uneventful. Extensive local bone formation was observed in animals receiving implants adsorbed with rhBMP-2 (2.0 mg/ml). The newly formed bone exhibited a specific pinpoint bone,implant contact pattern regardless of rhBMP-2 concentration resulting in significant osseointegration; rhBMP-2 (2.0 mg/ml): 43% and rhBMP-2 (0.2 mg/ml): 37%. Control implants exhibited a thin layer of bone covering a relatively larger portion of the implant threads. Thus, TPO control implants bone exhibited significantly greater bone,implant contact (,75%; p<0.05). There were no statistically significant differences between rhBMP-2-coated and control implants relative to any other parameter including peri-implant and intra-thread bone density. Conclusion: rhBMP-2-coated TPO implants enhanced/accelerated local bone formation in Type IV bone in a dose-dependent fashion in non-human primates resulting in significant osseointegration. rhBMP-2-induced de novo bone formation did not reach the level of osseointegration observed in native resident bone within the 16-week interval. [source]

    Bone formation at rhBMP-2-coated titanium implants in the rat ectopic model

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 5 2007
    Jan Hall
    Abstract Background: The objective of this study was to evaluate local bone formation at titanium porous oxide (TPO) implant surfaces adsorbed with recombinant human bone morphogenetic protein-2 (rhBMP-2). Methods: In vitro studies were used to estimate the kinetics of I125 -labeled rhBMP-2 released from TPO surfaces with narrow (N) or open (O) pores. Machined/turned titanium (MT) surfaces served as control. The rat ectopic model was used to assess local bone formation. Briefly, TPO-N, TPO-O, and MT disc implants adsorbed with 5, 10, or 20 ,g rhBMP-2, respectively, were implanted subcutaneously into the ventral thoracic region in 5-week-old male Long Evans rats. The animals were euthanized at day 14 postsurgery when implants with surrounding tissues were removed, radiographed, and gross observations recorded. The specimens were processed for histologic evaluation using conventional cut-and-grind techniques. TPO implants without rhBMP-2 included in a preliminary evaluation revealed no evidence of bone formation, tissue encapsulation, or vascularity, thus such controls were not further used. Results: TPO and MT implant surfaces adsorbed with 5 ,g rhBMP-2 retained 2.3,5.4% rhBMP-2 following immersion and rinse in buffer, and 1.1,2.2% rhBMP-2 following repeated immersions and rinses over 27 days. TPO implants retained the most rhBMP-2 and MT implants retained the least. Explants revealed increased hard tissue formation, tissue encapsulation, and vascularity at TPO compared with MT implants. Radiographic observations were consistent with the explant observations. The histologic analysis showed greater amounts of bone formation, osteoblastic cells, osteoid, marrow, tissue encapsulation, vascularity, and bone voids for implants adsorbed with 10 and 20 ,g rhBMP-2, and for TPO implants at the 5- ,g rhBMP-2 dose. The histometric analysis revealed significantly greater bone formation at TPO-O than at MT implants at the 5- ,g rhBMP-2 dose. All surfaces showed significant bone formation at the 10- and 20- ,g dose. Conclusions: rhBMP-2 adsorbed onto TPO implant surfaces executes an osteoinductive effect including bone contacting the implant surface. This effect is surface- and dose-dependent; the TPO-O surface yielding the most bone at the low discriminating rhBMP-2 dose. [source]

    Bone formation at titanium porous oxide (TiUniteÔ) oral implants in type IV bone

    CLINICAL ORAL IMPLANTS RESEARCH, Issue 1 2005
    Yi-Hao Huang
    Abstract Background: Several oral implant design advances have been suggested to overcome poor bone quality, an impediment for successful implant treatment. A novel titanium porous oxide (TPO) surface has been shown to offer favorable results in several settings. The objective of this study was to evaluate the local bone formation and osseointegration at TPO-modified implants in type IV bone. Method: Three TPO surface-modified implants (TiUniteÔ) were installed into the edentulated posterior maxilla in each of 8 Cynomolgus monkeys. The animals were injected with fluorescent bone labels at 2, 3, 4 and 16 weeks post-surgery and were euthanized at week 16 when block biopsies were collected for histologic analysis. Results: The predominant observation of the TPO implant surface was a thin layer of new bone covering most of the implant threads. Mean (±SE) bone,implant contact for the whole study group was 74.1±4.8%. There was a significant variability in bone,implant contact between animals (P=0.0003) and between sites of the same animal (P<0.0001). The variance in bone,implant contact was 30% larger among sites of the same animal than between different animals (187.5 vs. 144.8, respectively). There was a small but significant difference in bone density immediately outside, compared to within the threaded area of the implants (37.1±3.2% vs. 32.1±3.2%, P<0.0001). Bone density outside the implant threads was significantly correlated (,=0.682, P<0.0001) with the bone density within thethreaded area. Bone density within the threaded area was significantly correlated (,=0.493, P=0.0002) with bone,implant contact, whereas bone density outside the implant threads did not have a significant effect (,=0.232, P=0.1). Conclusions: The results suggest that the TPO surface possesses a considerable osteoconductive potential promoting a high level of implant osseointegration in type IV bone in the posterior maxilla. Résumé Différents nouveaux modèles d'implants ont été suggéréspour tenter de compenser la mauvaise qualité osseuse qui est un problème pour le traitement implantaire à succès. Une nouvelle surface en oxyde poreux de titane (TPO) a apporté des résultats favorables en différentes occasions. L'objectif de cette étude a été d'évaluer la formation osseuse locale et l'ostéoïntégration d'implants modifiés TPO dans de l'os de qualité type IV. Trois implants dont la surface était modifiée TPO (TiUniteTM) ont été insérés dans un maxillaire édenté postérieur de huit singes cynomolgus. Les animaux ont subi des injections de marqueurs osseux par flurorescence à deux, trois, quatre et seize semaines après la chirurgie et ont été euthanasiés à la semaine 16 quand des biopsies en bloc ont été prélevées pour l'analyse histologique. L'observation prédominante de la surface implantaire TPO était une fine couche de nouvel os couvrant la plupart des filetages implantaires. La moyenne ±SE du contact os-implant pour tout le groupe étudiéétait de 74±5%. Il y avait une variation significative dans le contact os-implant entre les animaux (P<0,0003) et entre les sites d'un même animal (P<0,0001). La variance du contact os-implant était 30% plus importante parmi les sites du même animal qu'entre différents animaux (respectivement 187 et 145). Il y avait une différence significative bien que faible dans la densité osseuse immédiatement á l'extérieur comparéà l'intérieur des zones à filetage des implants (37±3% vs 32±3%, P<0,0001). La densité osseuse en dehors des filetages implantaires était en corrélation significative (ß=0,682, P<0,0001) avec la densité osseuse à l'intérieur des zones de filetage. La densité osseuse à l'intérieur des zones de filetage était en corrélation significative (ß=0,493, P<0,0002) avec le contact os-implant, tandis que la densité osseuse en dehors des filetages implantaires n'avait pas d'effet significatif (ß=0,232, P=0,1). Ces résultats suggèrent que la surface TPO possède un potentiel ostéoconducteur considérable qui peut promouvoir une ostéoïntégration implantaire de haut niveau dans l'os de type IV dans la région maxillaire postérieure. Zusammenfassung Ziel: Um trotz schlechter Knochenqualität die Aussicht auf eine erfolgreiche implantologische Behandlung zu verbessern, wurden verschiedene Entwicklungen des Designs von Zahnimplantaten vorgeschlagen. Bei verschiedenen Gelegenheiten hat eine neue poröse Titanoxidoberfläche (TPO) scheinbar vorteilhafte Resultate gezeigt. Das Ziel dieser Studie war, die lokale Knochenbildung und die Osseointegration von Implantaten mit einer TPO-modifizierten Oberfläche im Typ IV Knochen zu untersuchen. Methode: In die zahnlosen posterioren Oberkiefern eines jeden von 8 Cynomolgus-Affen implantierte man drei Implantate mit einer TPO-modifizierten Oberfläche (TiUnite®). Den Tieren wurden 2, 3, 4 und 16 Wochen nach dem chirurgischen Eingriff fluoreszierende Knochenmarker injiziert und in der Wochen 16 wurden sie eingeschläfert und für die histologische Analyse Blockbiopsien entnommen. Resultate: Die wichtigste Beobachtung bei der TPO-Implantatoberfläche war eine dünne Schicht neuen Knochens, welche die meisten Schraubenwindungen des Implantates bedeckte. Der mittlere Knochen-Implantatkontakt (±SE) betrug in der ganzen Testgruppe 74.1±4.8%. Man fand eine signifikante Variabilität des Knochen-Implantatkontaktes unterhalb der Tiere (P=0.0003) und auch unterhalb der verschiedenen Impantate desselben Tieres (P<0.0001). Innerhalb der Implantate desselben Tieres war die Varianz des Knochen-Implantatkontaktes bis zu 30% grösser, als zwischen den verschiedenen Tieren (187.5 gegenüber 144.8). Man fand auch einen kleinen, aber signifikanten Unterschied der Knochendichte im Bereich direkt ausserhalb der Schraubenwindungen, verglichen mit dem inneren Bereich (37.1±3.2% gegenüber 32.1±3.2%, P<0.0001). Diese beiden Knochendichten waren aber signifikant miteinander korreliert (0.682, P<0.0001). Die Knochendichte innerhalb der Schraubenwindungen korrelierte signifikant mit dem Knochen-Implantat-Kontakt (ß=0.493, P=0.0002), währenddem die Knochendichte ausserhalb des Bereiches der Schraubenwindungen in dieser Beziehung keine signifikante Korrelation aufwies (ß=0.232, P=0.1). Zusammenfassung: Die Resultate lassen vermuten, dass die TPO-Oberfläche eine beachtliche osteokonduktive Fähigkeit hat, die im posterioren Oberkieferbereich mit Typ IV Knochen zu einer sehr guten Osseointegration führt. Resumen Antecedentes: Se han sugerido varios avances en los diseños de los implantes orales para superar una baja calidad de hueso, un impedimento para un tratamiento exitoso de implantes. Se ha presentado una nueva superficie de óxido de titanio poroso (TPO) que ofrece resultados favorables en diversas situaciones. El objetivo de este estudio fue evaluar la formación local de hueso y la osteointegración en implantes TPO modificados en hueso tipo IV. Método: Se instalaron tres implantes (TiUniteTM) con superficie modificada TPO en el maxilar posterior edéntulo en 8 monos Cynomolgus. Los animales fueron inyectados con marcadores óseos fluorescentes en la semana 2, 3, 4 y 16 tras la cirugía y se sacrificaron en la semana 16 recogiéndose biopsias en bloque para análisis histológicos. Resultados: La observación predominante de la superficie TPO del implante fue una fina capa de hueso nuevo cubriendo la mayor parte de las roscas. El contacto hueso-implante medio (±SE) para todo el grupo de estudio fue de 74.1±4.8%. Hubo una variabilidad significativa en el contacto hueso-implante entre animales (P=0.0003) y entre lugares del mismo animal (P<0.0001). La varianza en el contacto hueso-implante fue un 30% mayor entre lugares del mismo animal que entre los diferentes animales (187.5 vs. 144.8, respectivamente). Hubo una pequeña pero significativa diferencia en la densidad ósea inmediatamente por fuera comparada con el área roscada de los implantes (37.1±3.2% vs. 32.1±3.2%, P<0.0001). La densidad ósea por fuera de las roscas del implante se correlacionó significativamente (,=0.682, P<0.0001) con la densidad ósea entre las áreas de roscas. La densidad ósea entre las áreas de roscas se correlacionó significativamente (,=0.492, P<0.0002) con el contacto hueso implante, mientras que la densidad ósea por fuera de las roscas del implante no tuvo un efecto significativo (,=0.232, P=0.1). Conclusiones: Los resultados sugieren que la superficieTPOposee un considerable potencial osteoconductivo promoviendo un alto nivel de osteointegracióndel implante en hueso tipo IV en el maxilar posterior. [source]