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Grafting Procedures (grafting + procedure)

Distribution by Scientific Domains
Medical Sciences65%
Life Sciences20%
Chemistry10%

Kinds of Grafting Procedures

  • bone grafting procedure
    		•

    Selected Abstracts

    Synthesis of PEGylated single wall carbon nanotubes by a photoinitiated graft from polymerization

    AICHE JOURNAL, Issue 6 2010
    Pu Zhang
    Abstract A considerable amount of research has been devoted to carbon nanotubes because of their unique electrical, mechanical, optical, and chemical properties. Here, in this report, we introduce a novel, simple ultraviolet initiated "graft from" polymerization method to synthesize PEGylated carbon nanotubes. This grafting procedure significantly enhanced nanotube aqueous dispersibility and long term stability in solution. Mass of grafted polymer chains was easily modulated by adjusting polymerization reaction time, and nanomaterials containing up to 80% polymer by weight were synthesized. Nanotube morphology was characterized by SEM, TEM before and after the functionalization. In addition, the covalent bonding of polymer chains to the nanotubes structure was elucidated by Raman, ATR-FTIR, and XPS spectroscopy. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source]

    Early steps in neural development

    JOURNAL OF MORPHOLOGY, Issue 7 2006
    Marc Callebaut
    Abstract We studied early neurulation events in vitro by transplanting quail Hensen's node, central prenodal regions (before the nodus as such develops), or upper layer parts of it on the not yet definitively committed upper layer of chicken anti-sickle regions (of unincubated blastoderms), eventually associated with central blastoderm fragments. We could demonstrate by this quail-chicken chimera technique that after the appearance of a pronounced thickening of the chicken upper layer by the early inductive effect of neighboring endophyll, a floor plate forms by insertion of Hensen's node-derived quail cells into the median part of the groove. This favors, at an early stage, the floor plate "allocation" model that postulates a common origin for notochord and median floor plate cells from the vertebrate's secondary major organizer (Hensen's node in this case). A comparison is made with results obtained after transplantation of similar Hensen's nodes in isolated chicken endophyll walls or with previously obtained results after the use of the grafting procedure in the endophyll walls of whole chicken blastoderms. J. Morphol. © 2006 Wiley-Liss, Inc. [source]

    Mechanical characteristics of the bone,graft,cement interface after impaction allografting

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2005
    Hanspeter Frei
    Impaction allografting is an attractive procedure for the treatment of failed total hip replacements. The graft,cement,host bone interface after impaction allografting has not been characterized, although it is a potential site of subsidence for this type of revision total hip reconstruction. In six human cadaveric femurs, the cancellous bone was removed proximally and local diaphyseal lytic defects were simulated. After the impaction grafting procedure, the specimens were sectioned in 6 mm transverse sections and pushout tests were performed. From the adjacent sections the percentage cement contact of the PMMA cement with the endosteal bone surface was determined. The host bone interface mechanical properties varied significantly along the femur largely due to different interface morphologies. The apparent host bone interface shear strength was highest around the lesser trochanter and lowest around the tip of the stem. A significant positive correlation was found between the percentage cement contact and the apparent host bone interface shear strength (r2 = 0.52). The sections failed in 69% of the cases through a pure host bone interface failure without cement or allograft failure, 19% failed with local cement failure, and 12% with a local allograft failure. The apparent host bone interface strength was on average 89% lower than values reported for primary total hip replacements and were similar to cemented revisions proximally and lower distally. This study showed that cement penetration to the endosteal surface enhanced the host bone,graft interface. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source]

    Use of a Mini-Dome Bioassay and Grafting to Study Resistance of Chickpea to Ascochyta Blight

    JOURNAL OF PHYTOPATHOLOGY, Issue 10 2005
    W. Chen
    Abstract A mini-dome bioassay was developed to study pathogenicity of Ascochyta rabiei and relative resistance of chickpea (Cicer arietanium). It was determined that the best condition for assaying pathogenicity of A. rabiei was to use 2 × 105 spores/ml as inoculum and to maintain a leaf wetness period of 24 h under mini-domes at a temperature between 16 and 22°C. This mini-dome pathogenicity assay was used to determine relative resistance of six chickpea cultivars (cvs) to isolates of two pathotypes of A. rabiei. Grafting was employed to detect any translocated factors produced in the chickpea plant that mediate disease response, which could help elucidate possible resistance mechanisms to Ascochyta blight. The six chickpea cv. were grafted in all possible scion,rootstock combinations, and then inoculated with isolates of two pathotypes of A. rabiei using the mini-dome technique. Results showed that self-grafted-resistant plants remained resistant and self-grafted-susceptible plants stayed susceptible, indicating the grafting procedure did not alter host response to infection by A. rabiei. Susceptible scions always exhibited high and similar levels of disease severity regardless of rootstock genotypes, and resistant scions always showed low and similar levels of disease severity when they were grafted onto any of the six rootstock genotypes. Orthogonal contrasts showed that scion genotypes determined disease phenotype, and that rootstock genotypes had no contribution to disease phenotype of the scions. The pathogenicity assay did not detect any translocated disease-mediating agents responsible for susceptibility or resistance in chickpea. Disease phenotypes of Ascochyta blight of chickpea were conditioned locally by scion genotypes. [source]

    Alkylated poly(styrene-divinylbenzene) monolithic columns for ,-HPLC and CEC separation of phenolic acids

    JOURNAL OF SEPARATION SCIENCE, JSS, Issue 17 2007
    Zdenka Ku, erová
    Abstract Macroporous poly(styrene-divinylbenzene) monolithic columns were prepared in fused silica capillaries of 100 ,m id by in-situ copolymerization of styrene with divinylbenzene in the presence of propan-1-ol and formamide as the porogen system. The monoliths were subsequently alkylated with linear alkyl C-18 groups via Friedel-Crafts reaction to improve the retention and chromatographic resolution of strongly polar phenolic acids. A new thermally initiated grafting procedure was developed in order to shorten the time of the alkylation process. The grafting procedure was optimized with respect to the reaction temperature, time, the grafting reactant concentration, and the solvent used. The type of solvent and the grafting temperature are the most significant factors affecting the hydrodynamic properties, porosity, and efficiency of the columns. While the equivalent particle diameter of the grafted column increased, the capillary-like flow-through pore diameter decreased in comparison to non-alkylated monoliths. The hydrodynamic permeability of the monolith decreased, but the monolithic column still permitted fast ,-HPLC separations. [source]

    Leptin, soluble interleukin-6 receptor, C-reactive protein and soluble vascular cell adhesion molecule-1 levels in human coronary atherosclerotic plaque

    CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2006
    M. Karaduman
    Summary The aim of the present study was to explore the relationship between tissue levels of leptin, soluble interleukin-6 receptor (sIL-6R), high-sensitive-C-reactive protein (hs-CRP) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in atherosclerotic plaques, and traditional risk factors. Coronary artery specimens were obtained from 35 consecutive patients (26 men and nine women) who underwent coronary artery bypass grafting procedure. The mean tissue levels of leptin, hs-CRP and sIL-6R were significantly higher in patients with diabetes mellitus than without diabetes mellitus. When patients were classified according to the smoking status, the mean tissue levels of leptin, hs-CRP and sIL-6R were significantly higher in current smokers than both former smokers and non-smokers. In addition, the mean tissue levels of leptin and sIL-6R were significantly higher in former smokers than non-smokers. There was a positive association between leptin and hs-CRP, sIL-6R and plasma glucose in all patients. Plasma HDL levels were associated negatively with atherosclerotic tissue levels of leptin. Tissue levels of sIL-6R were associated significantly in a positive manner with leptin, hs-CRP and plasma glucose, while tissue levels of hs-CRP were associated with both leptin and sIL-6R. In conclusion, it is attractive to speculate that hs-CRP, sIL-6R and leptin could act synergistically in course of local inflammatory activity and those molecules may not be just markers of inflammation and cardiovascular risk but are also likely to play a pathogenic role in atheromatous plaque. In addition, atherosclerotic tissue levels of CRP, sIL-6R and leptin were significantly higher in current smokers and patients with diabetes. [source]

    Histologic findings at augmented bone areas supplied with two different bone substitute materials combined with sinus floor lifting

    CLINICAL ORAL IMPLANTS RESEARCH, Issue 1 2004
    Report of one case
    Abstract: This case report is focused on the histologic findings of bone tissue supplied with two different hydroxyapatites (HAs) used for maxillary sinus floor grafting in the same patient after various healing intervals. An insufficient unilateral sinus floor grafting with Bio-Oss® biomaterial was followed by an additional grafting procedure with Algipore® biomaterial performed 4 years later. Bone samples obtained during second-stage dental implantation contained the interesting combination of Bio-Oss®, a bovine anorganic bone substitute, and Algipore®, a porous algae-derived HA, in close vicinity, yet after different healing periods. Light microscopy exhibited satisfactory osseointegration of both grafting materials. However, Bio-Oss® biomaterial showed no evidence of substantial remodeling after a healing period of 4.5 years. On the other hand, Algipore® particles demonstrated signs of remodeling by being locally resorbed and partially replaced with newly formed bone already within 6 months. Résumé Ce rapport d'un cas se concentre sur les découvertes histologiques du tissu osseux apporté par deux hydroxyapatites différents utilisés pour l'épaississement du plancher sinusal chez le même patient après différents intervalles de guérison. Un épaississement sinusal unilatéral insuffisant effectué avec le Bio-Oss® a été suivi d'un nouveau processus d'épaississement avec le Algipore® (un hydroxyapatite biologique dérivé d'algues marines calcifiées) quatre ans plus tard. Des échantillons osseux obtenus durant le placement des implants contenaient la combinaison intéressante du Bio-Oss®, un substitut osseux inorganique bovin, et du Algipore®, un hydroxyapatite d'algues, l'un à côté de l'autre, même si il y avait des périodes de guérison différentes. La microscopie optique a montré une ostéoïntégration satisfaisante des deux matériaux greffés. Cependant, le Bio-Oss® ne montrait aucune évidence d'un remodelage substantiel après une période de 4,5 années. Par contre les particules de Algipore® possèdaient des signes de remodelage tout en étant résorbées localement et partiellement remplacées par de l'os néoformé déjà après six mois. Zusammenfassung Diese Fallvorstellung präsentiert die Histologie eines Knochens, der bei einer in zwei Schritten und mit verschiedenen Hydroxylapatitprodukten durchgeführten Sinusbodenelevation entstanden ist. Die Einheilzeit der zwei Transplantate war verschieden lang. Eine einseitig durchgeführte und ungenügende Sinusbodenelevation mit dem Biomaterial Bio-Oss® wurde vier Jahre später mit einem zusätzlichen Augmentationseingriff unter Einsatz des Biomaterials Algipore® korrigiert. Bei der Implantation konnte man Knochenproben von interessanter Zusammensetzung entnehmen. Es handelte sich um einen Knochen, der während verschieden langer Zeit in engem Kontakt mit Bio-Oss®, einem anorganischen Rinderknochentransplantat, und Algipore®, einem porösen aus Algen gewonnenem Hydroxylapatit stand. Die Lichtmikroskopie zeigte eine zufriedenstellende Osseointegration beider Transplantatmaterialien. Bio-Oss® zeigte jedoch nach einer Einheilzeit von 4.5 Jahren noch keine Anzeichen einer substanziellen Remodellation. Bei den Algipore® Partikeln war dies bereits der Fall. Sie waren schon nach sechs Monaten an einigen Stellen anresorbiert, teilweise sogar mit neu gebildetem Knochen ersetzt. Resumen Este informe de un caso esta enfocado sobre los hallazgos histológicos de tejido óseo suministrado con dos diferentes hidroxiapatitas usadas para injerto del suelo del seno maxilar en el mismo paciente tras varios intervalos de cicatrización. Un insuficiente injerto del suelo del seno con biomaterial Bio-Oss® fue seguido por un procedimiento adicional de injerto con biomaterial Algipore® llevado a cabo 4 años mas tarde. Las muestras de hueso obtenidas durante la segunda fase de la implantación dental contenían una interesante combinación de Bio-Oss®, un sustituto óseo inorgánico bovino y Algipore®, una hidroxiapatita porosa derivada de algas, en próxima vecindad, aunque tras diferentes periodos de cicatrización. La microscopía óptica exhibió una osteointegración satisfactoria de ambos materiales de injerto. De todos modos, el biomaterial Bio-Oss® no mostró evidencia de un remodelado sustancial tras un periodo de cicatrización de 4.5 años. Por otro lado las partículas de Algipore® demostraron signos de remodelado al ser localmente reabsorbidas y reemplazadas parcialmente con hueso neoformado ya a los 6 meses. [source]

    Introduction of an OPCAB Program Aimed at Total Arterial Grafting in a Multidisciplinary Setting: Feasible and Safe?

    JOURNAL OF CARDIAC SURGERY, Issue 2 2007
    Xavier M. Mueller M.D.
    Uniform surgical and anesthetic protocols were established and applied throughout the study period. Methods: From March 2003,when the first OPCAB procedure of the program was performed,to July 2004, the data related to all the coronary artery bypass grafting procedures (N = 408) were prospectively recorded. The program was divided into two stages: the purpose of the first stage was to perform OPCAB in more than 90% of the patients, and that of the second stage was to proceed toward total arterial revascularization. The patients were grouped into four periods (102 patients for each period). Comparisons were performed with analysis of variance test and chi-square test where appropriate. Results: For periods 1 to 4, the number of OPCAB procedures was 65/102 (64%), 82/102 (80%), 97/102 (95%), and 99/102 (97%), respectively (p < 0.001). The number of conversions did not vary significantly throughout the study (overall: 7/408, 1.7%), neither did the number of bypass/patient (overall: 3.05 ± 0.86). The number of arterial graft/patient was 1.03 ± 0.64, 1.01 ± 0.4, 1.29 ± 0.64, and 2.56 ± 1, respectively (p < 0.001). During the last period, 81% (253/312) of the grafts were arterial. Overall mortality was 4.6% (19/408). For the OPCAB group, mortality was 2.9% (10/343) and perioperative myocardial infarction rate was 1.5% (5/343) with no statistically significant difference between the periods. Conclusions: With predefined standardized and coordinated protocols, an OPCAB program aimed at total arterial revascularization can be implemented rapidly and safely in a multidisciplinary setting. [source]

    Evaluation of processed bovine cancellous bone matrix seeded with syngenic osteoblasts in a critical size calvarial defect rat model

    JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2006
    U. Kneser
    Abstract Introduction: Biologic bone substitutes may offer alternatives to bone grafting procedures. The aim of this study was to evaluate a preformed bone substitute based on processed bovine cancellous bone (PBCB) with or without osteogenic cells in a critical size calvarial defect rat model. Methods: Discs of PBCB (Tutobone®) were seeded with second passage fibrin gel-immobilized syngenic osteoblasts (group A, n = 40). Cell-free matrices (group B, n = 28) and untreated defects (group C; n=28) served as controls. Specimens were explanted between day 0 and 4 months after implantation and were subjected to histological and morphometric evaluation. Results: At 1 month, bone formation was limited to small peripheral areas. At 2 and 4 months, significant bone formation, matrix resorption as well as integration of the implants was evident in groups A and B. In group C no significant regeneration of the defects was observed. Morphometric analysis did not disclose differences in bone formation in matrices from groups A and B. Carboxyfluorescine-Diacetate-Succinimidylester (CFDA) labeling demonstrated low survival rates of transplanted cells. Discussion: Osteoblasts seeded into PBCB matrix display a differentiated phenotype following a 14 days cell culture period. Lack of initial vascularization may explain the absence of added osteogenicity in constructs from group A in comparison to group B. PBCB is well integrated and represents even without osteogenic cells a promising biomaterial for reconstruction of critical size calvarial bone defects. [source]

    The amount of newly formed bone in sinus grafting procedures depends on tissue depth as well as the type and residual amount of the grafted material

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2005
    Zvi Artzi
    Abstract Objectives: Bone replacement substitutes are almost unavoidable in augmentation procedures such as sinus grafting. The objective of the present study was to evaluate the osteoconductive capability of two different scaffold fillers in inducing newly formed bone in this procedure. Material and Methods: Sinus floor augmentation and implant placement were carried out bilaterally in 12 patients. Bovine bone mineral (BBM) was grafted on one side and , -tricalcium phosphate (, -TCP) on the contralateral side. Both were mixed (1:1 ratio) with autogenous cortical bone chips harvested from the mandible by a scraper. Hard tissue specimen cores were retrieved from the augmented sites (at the previous window area) at 12 months. Decalcified sections were stained with haematoxylin,eosin and the fraction area of new bone and filler particles was measured. In addition to the effect of the filler on new bone formation, the latter was tested to determine whether it correlated with the tissue depth and residual amount of the grafted material. Results: Bone area fraction increased significantly from peripheral to deeper areas at both grafted sites in all cores: from 26.0% to 37.7% at the , -TCP sites and from 33.5% to 53.7% at the BBM-grafted sites. At each depth the amount of new bone in BBM sites was significantly greater than that in TCP sites. However, the average area fraction of grafted material particles was similar in both fillers and all depth levels (, -TCP=27.9,23.2% and BBM=29.2,22.6%, NS). A significant negative correlation was found between bone area fraction and particle area fraction at the middle (p=0.009) and deep (p=0.014) depths in the , -TCP sites, but not at the BBM sites. Conclusion: At 12 months post-augmentation, the two examined bone fillers, , -TCP and BBM, promoted new bone formation in sinus grafting but the amount of newly formed bone was significantly greater in BBM-grafted sites. However, both exhibited similar residual grafted material area fraction at this healing period. This could imply that BBM possesses better osteoconductive properties. [source]

    The effect of a fibrin glue on the integration of Bio-Oss® with bone tissue

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 5 2002
    An experimental study in labrador dogs
    Abstract Background: Bio-Oss® is a deproteinized bovine mineral used in bone augmentation procedures. The particles are often mixed with a protein product (Tisseel®) to form a mouldable graft material. Aim: The aim of the present experiment was to study the healing of self-contained bone defects after the placement of Bio-Oss® particles alone or mixed with Tisseel® in cylindrical defects in the edentulous mandibular ridge of dogs. Material and methods: In 4 labrador dogs, the 2nd, 3rd and 4th mandibular premolars were extracted bilaterally. 3 months later, 3 cylindrical bone defects, 4 mm in diameter and 8 mm in depth, were produced in the right side of the mandible. Following a crestal incision, full thickness flaps were raised and the bone defects were prepared with a trephine drill. The defects were filled with Bio-Oss® (Geistlich Biomaterials, Wolhuser, Switzerland) particles alone or mixed with Tisseel® (Immuno AG, Vienna, Austria), or left "untreated". A collagen membrane (Bio-Gide®, Geistlich Biomaterials, Wolhuser, Switzerland) was placed to cover all defects and the flaps were sutured. 2 months later, the defect preparation and grafting procedures were repeated in the left side of the mandible. After another month, the animals were sacrificed and biopsies obtained from the defect sites. Results: Bio-Oss® -treated defects revealed a higher percentage of contact between graft particles and bone tissue than defects treated with Bio-Oss®+ Tisseel® (15% and 30% at 1 and 3 months versus 0.4% and 8%, respectively). Further, the volume of connective tissue in the Bio-Oss® treated defects decreased from the 1 to the 3 month interval (from 44% to 30%). This soft tissue was replaced with newly formed bone. In the Bio-Oss®+ Tisseel® treated defects, however, the proportion of connective tissue remained unchanged between 1 and 3 months. Conclusion: The adjunct of Tisseel® may jeopardize the integration of Bio-Oss® particles with bone tissue. Zusammenfassung Hintergrund: Bio-Oss® ist ein entproteiniertes Mineral vom Schwein, was bei knöchernen Augmentationen verwendet wird. Die Partikel werden oft mit einem Proteinprodukt gemischt, um ein formbares Implantationsmaterial zu erhalten. Ziel: Das Ziel des vorliegenden Experimentes war das Studium der Heilung von selbst-erhaltenden Knochendefekten nach der Anwendung von Bio-Oss® Partikeln allein oder vermischt mit Tisseel® in zylindrischen Defekten im zahnlosen unteren Kieferkamm von Hunden. Materal und Methoden: Bei 4 Labradorhunden wurden die 2., 3. und 4. unteren Prämolaren beidseitig extrahiert. 3 Monate später wurden 3 zylindrische Knochendefekte, 4 mm im Durchmesser und 8 mm tief, auf der rechten Seite des Unterkiefers hergestellt. Nach einer krestalen Incision wurde ein voller Mukoperiostlappen mobilisiert und die knöchernen Defekte mit einem Trepanfräser präpariert. Die Defekte wurden mit Bio-Oss® Partikeln (Geistlich Biomaterial, Wolhuser, Schweiz) allen oder gemischt mit Tisseel® (Immuno AG, Wien, Österreich) gefüllt oder blieben "unbehandelt". Eine Kollagenmembran (Bio-Gide®, Geistlich Biomaterial, Wolhuser, Schweiz) wurde zur Abdeckung über alle Defekte gelegt und die Lappen reponiert und vernäht. 2 Monate später wurden die Defektpräparationen und die Implantationsmaßnahmen auf der linken Seite des Unterkiefers widerholt. Nach einem weiteren Monat wurden die Tiere getötet und Biopsien von den Defektseiten gewonnen. Ergebnisse: Mit Bio-Oss® behandelte Defekte zeigten einen höheren Prozentsatz von Kontakt zwischen Implantationsmaterial und Knochengewebe als die Defekte, die mit Bio-Oss® und Tisseel® behandelt worden waren (15% und 30% zum 1. Monat und 3. Monat versus 0.4% und 8%). Weiterhin verringerte sich das Volumen des Bindegewebes in den mit Bio-Oss® behandelten Defekten vom 1. zum 3. Monat (von 44% zu 30%). Dieses Weichgewebe wurde mit neu gebildetem Knochen ersetzt. In dem mit Bio-Oss® und Tisseel® behandelten Defekten blieb die Verteilung des Bindegewebes zwischen dem 1. und 3. Monat unverändert. Zusammenfassung: Die Zugabe von Tisseel® kann die Integration von Bio-Oss® Partikeln mit Knochengewebe behindern. Résumé Origine: Le Bio-Oss® est un minéral bovin déprotéine utilisé pour les épaississements osseux. Les particules sont souvent mélangées avec un produit protéiné (Tisseel®) pour former un matérial de greffe malléable. But. Le but de l'étude présente a été d'étudier la guérison des lésions osseuses après le placement de particules de Bio-Oss® seules ou mélangées au Tisseel® dans des lésions cylindriques au niveau de la mandibule édentée de labradors. Matériaux et méthodes: Chez 4 labradors les 2ièmes, 3ièmes et 4ièmes prémolaires inférieures ont été avulsées bilatéralement. 3 mois après, 3 lésions osseuses et cylindriques de 4 mm de diamètre et de 8 mm de profondeur ont été produites du côté droit de la mandibule. A la suite d'une incision crestale, des lambeaux d'épaisseur complète ont été relevés et les lésions osseuses préparées avec un trépan. Les lésions ont été comblées par des particules de Bio-Oss® seul (Geistlich Biomaterials, Wolhuser, Suisse) ou mélangées au Tisseel® (Immuno AG, Vienne) ou laissées non-traitées. Une membrane collagène (Bio-Gide®, Geistlich Biomaterials, Wolhuser, Suisse) a été placée pour recouvrir toutes les lésions et les lambeaux ont ensuite été suturés. 2 mois après, les processus précités ont été répétés au niveau gauche de la mandibule. 1 mois plus tard, les animaux ont été tués et les biopsies prélevées. Résultats: Les lésions traitées par le Bio-Oss® ont révélé un % plus important de contact entre les particules du greffon et le tissu osseux que les lésions traitées avec le Bio-Oss®+Tisseel® (respectivement 15% à 30% à 1 et 3 mois versus 0.4% et 8%). De plus le volume de tissu conjonctif dans les lésions traitées par Bio-Oss® diminuait du mois 1 au mois 3, de 44 à 30%. Ce tissu mou a été remplacé par un os néoformé. Dans les lésions traitées par Bio-Oss®+Tisseel®, la proportion de tissu conjonctif demeurait inchangée entre les mois 1 et 3. Conclusions: L'addition de Tisseel® peut mettre en péril l'intégration des particules de Bio-Oss® au tissu osseux. [source]

    Recombinant human bone morphogenetic protein-7 in maxillary sinus floor elevation surgery in 3 patients compared to autogenous bone grafts

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 9 2000
    A clinical pilot study
    Abstract Background/Aims: This pilot study was designed to determine the clinical bone formation ability of a human recombinant DNA bone morphogenetic protein-7, also referred to as Osteogenic Protein-1 [OP-1] combined with a collagen carrier, implanted in the maxillary sinus of 3 patients. The results were compared with a group of 3 patients treated with sinus floor elevation and autogenous bonegrafts. Methods: 6 consecutive patients, 4 female and 2 male, between 48 and 57 years of age were treated by means of sinus floor elevation for insufficient bone height in the posterior maxilla for implant surgery. 3 patients, 2 female and 1 male, were treated with OP-1 attached to a collagen device. In these patients, 4 maxillary sinus grafting procedures according to Tatum's method were carried out. 1 g of collagen carrier containing 2.5 mg rhOP-1 mixed with 3 ml of saline was placed between the bony floor and the elevated mucosal lining of the most caudal part of the maxillary sinus, in order to increase the vertical bone dimension to place dental implants of a sufficient length. The 3 other patients, also 2 female and 1 male, with a total of 5 sinus sites, were treated with sinus floor elevation and autogenous iliac crest bonegrafts. After 6 months, during dental implant preparation, bone cores were taken for histology. Thus, clinical, radiological and histological results of the 2 groups of 3 patients were compared. Results: 6 months after sinus grafting with OP-1, in 1 male, well-vascularized bonelike tissue of good quality was observed clinically. This could be confirmed by histology. In the second, female, patient no bone formation was observed at all. A cyst-like granular tissue mass, without purulent content, was removed. In the 3rd, female, patient, who received bilateral sinus grafts, some bonelike formation was seen, however it showed flexible tissue which led to the decision that at 6 months after the sinus grafting, the implant placement had to be postponed. In all 5 autogenous grafted sinuses a bone appearance similar to normal maxillary bone was observed clinically as well as histologically and dental implants could be placed six months after sinus floor elevation surgery. Conclusions: These findings indicate that the OP-1 device has the potential for initiating bone formation in the human maxillary sinus within 6 months after a sinus floor elevation operation. However, the various findings in these 3 patients indicate that the behaviour of the material is at this moment insufficiently predictable, in this indication area. Further investigation is indicated before OP-1 can be successfully used instead of the "gold standard" autogenous bone graft. [source]

    In vitro model of full-thickness cartilage defect healing

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 9 2007
    Hok Kei Tam
    Abstract Integration of the host,graft interface is implicated as one of the significant reasons for lack of complete healing in osteochondral grafting procedures for the treatment of cartilage lesions. We developed an in vitro model of cartilage healing in an osteochondral setting to study the effect of developmental age and collagenase treatment. Circular full-thickness vertical surgical incisions were made in the cartilaginous portion of cylindrical bovine osteochondral specimens. Two age groups were selected: Young (1,2 months old) and Older (6,8 months old). Cartilage integration across the surgical incisions was assessed by histologic analysis and by mechanical push-out testing at 2 and 4 weeks in culture. Histologic integration as well as peak push-out shear stress was significantly higher in older calf cartilage than in the young calf. Collagenase pretreatment in the older calf samples increased push-out strength at 4 weeks. Histologic integration correlated well with the mechanical push-out strength. Developmental age and time after injury affected the response to collagenase pretreatment. This osteochondral cartilage integration model can be useful to study factors that modulate healing of surgical replacement procedures in vitro, which may aid the development of newer approaches to promote the healing of cartilage defects. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1136,1144, 2007 [source]

    Poly(ethylene glycol) Surface Coated Magnetic Particles

    MACROMOLECULAR RAPID COMMUNICATIONS, Issue 18 2005
    Christophe Flesch
    Abstract Summary: A methacrylate-functionalized poly(ethylene glycol) macromonomer was copolymerized at the surface of methacrylate-derivatized maghemite nanoparticles. After silylation of the magnetic core with methacryloxypropyltrimethoxysilane, two grafting procedures based on either a direct copolymerization reaction in water or an inverse emulsion polymerization were compared. A direct copolymerization led to low polymer surface amounts, whereas an inverse emulsion process allowed nanocomposite particles containing up to 90 wt.-% polymer to be obtained. TEM picture of maghemite-PEG hybrid particles. [source]

    Interventions for replacing missing teeth: bone augmentation techniques for dental implant treatment

    AUSTRALIAN DENTAL JOURNAL, Issue 1 2009
    M Esposito
    Background:, Dental implants require sufficient bone to be adequately stabilized. For some patients implant treatment would not be an option without bone augmentation. A variety of materials and surgical techniques are available for bone augmentation. Objectives:, General objectives: To test the null hypothesis of no difference in the success, function, morbidity and patient satisfaction between different bone augmentation techniques for dental implant treatment. Specific objectives: (A) to test whether and when augmentation procedures are necessary; (B) to test which is the most effective augmentation technique for specific clinical indications. Trials were divided into three broad categories according to different indications for the bone augmentation techniques: (1) major vertical or horizontal bone augmentation or both; (2) implants placed in extraction sockets; (3) fenestrated implants. Search strategy:, The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched. Several dental journals were handsearched. The bibliographies of review articles were checked, and personal references were searched. More than 55 implant manufacturing companies were also contacted. Last electronic search was conducted on 9 January 2008. Selection criteria:, Randomized controlled trials (RCTs) of different techniques and materials for augmenting bone for implant treatment reporting the outcome of implant therapy at least to abutment connection. Data collection and analysis:, Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted independently and in duplicate. Authors were contacted for any missing information. Results were expressed as random-effects models using mean differences for continuous outcomes and odd ratios for dichotomous outcomes with 95% confidence intervals. The statistical unit of the analysis was the patient. Main results:, Seventeen RCTs out of 40 potentially eligible trials reporting the outcome of 455 patients were suitable for inclusion. Since different techniques were evaluated in different trials, no meta-analysis could be performed. Ten trials evaluated different techniques for vertical or horizontal bone augmentation or both. Four trials evaluated different techniques of bone grafting for implants placed in extraction sockets and three trials evaluated different techniques to treat bone dehiscence or fenestrations around implants. Authors' conclusions:, Major bone grafting procedures of resorbed mandibles may not be justified. Bone substitutes (Bio-Oss or Cerasorb) may replace autogenous bone for sinus lift procedures of atrophic maxillary sinuses. Various techniques can augment bone horizontally and vertically, but it is unclear which is the most efficient. It is unclear whether augmentation procedures at immediate single implants placed in fresh extraction sockets are needed, and which is the most effective augmentation procedure, however, sites treated with barrier plus Bio-Oss showed a higher position of the gingival margin when compared to sites treated with barriers alone. Non-resorbable barriers at fenestrated implants regenerated more bone than no barriers, however it remains unclear whether such bone is of benefit to the patient. It is unclear which is the most effective technique for augmenting bone around fenestrated implants. Bone morphogenetic proteins may enhance bone formation around implants grafted with Bio-Oss. Titanium may be preferable to resorbable screws to fixate onlay bone grafts. The use of particulate autogenous bone from intraoral locations, also taken with dedicated aspirators, might be associated with an increased risk of infective complications. These findings are based on few trials including few patients, sometimes having short follow up, and often being judged to be at high risk of bias. [source]

    A 5-Year Prospective Follow-Up Study of Implant-Supported Fixed Prostheses in Patients Subjected to Maxillary Sinus Floor Augmentation with an 80:20 Mixture of Bovine Hydroxyapatite and Autogenous Bone

    CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2004
    Mats Hallman DDS
    ABSTRACT Background: Prospective long-term follow-up studies evaluating the use of bone substitutes to enable dental implant placement and integration are rare. Purpose: This study was undertaken to evaluate the survival rate of dental implants placed 6 months after maxillary sinus floor augmentation using a mixture of 80% bovine hydroxyapatite (BH) and 20% autogenous bone (AB). Material and Methods: Twenty patients subjected to 30 maxillary sinus floor grafting procedures using fibrin glue and an 80:20 mixture of BH and AB to enable placement of dental implants 6 months later were followed for 5 years of functional loading. Clinical and radiographic examinations of the grafts and implants were performed. Results: After 5 years of functional loading with fixed bridges, 15 of 108 implants had been lost, giving a cumulative survival rate of 86%. The mean marginal bone loss after 5 years was 1.3 ± 1.1 mm. Conclusion: Grafting of the maxillary sinus with a mixture of BH and AB and later placements of turned implants could be performed with predictable long-term results. All but one of the patients who were observed had functional fixed bridges after 5 years of functional loading. [source]

    Long-term Follow-up of Severely Atrophic Edentulous Mandibles Reconstructed with Short Branemark Implants

    CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 4 2000
    Bertil Friberg DDS
    ABSTRACT Background: Oral implant treatment (Brånemark System) of edentulous mandibles has been presented in numerous studies. However, with regard to the severely atrophic lower jaw, no long-term follow-up studies with solely short implants are available. Purpose: The purpose of the present investigation was to retrospectively follow the long-term treatment outcome of patients with severely resorbed edentulous mandibles being subjected to oral implant placement with short (6,7 mm) Brånemark implants. Materials and Methods: A total of 247 standard (7 mm long, 3.75 mm) and 13 wide (6 mm long, 5 mm) implants were inserted in 49 patients, all of whom exhibited severe resorption of edentate mandibles. Fixed implant-supported prostheses were manufactured for 45 patients, whereas 4 patients received overdentures. The patients were followed for a mean period of 8 years (range, 1,14 yr). Results: Seventeen implants failed during the study period (cumulative implant survival rate 95.5% at 5-yr and 92.3% at 10-yr follow-up). Implant-supported constructions were worn continuously throughout the investigation by all study subjects. Marginal bone loss, measured after 1, 5, and 10 years of function, concurred with studies of Brånemark implants placed in more voluminous mandibles. No major clinical or construction complications occurred in the followed patients. Conclusions: The outcome of the present study showed that placement of short Brånemark implants without the use of bone grafting procedures for reconstruction of severely atrophic edentulous mandibles is a highly predictable treatment procedure. [source]

    ,-tricalcium phosphate in the early phase of socket healing: an experimental study in the dog

    CLINICAL ORAL IMPLANTS RESEARCH, Issue 4 2010
    Mauricio G. Araújo
    Abstract Objectives: The aim of this experiment was to analyze processes involved in the incorporation of ,-tricalcium phospate (TCP) particles in host tissue during healing following tooth extraction and grafting. Material and methods: Five beagle dogs were used. Four premolars in the maxilla (3P3, 2P2) were hemi-sected, the distal roots were removed and the fresh extraction socket filled with TCP. The tooth extraction and grafting procedures were scheduled in such a way that biopsies representing 1 and 3 days, as well as 1, 2, and 4 weeks of healing could be obtained. Tissue elements such as cells, fibers, vessels, leukocytes and mineralized bone were determined. In deparaffinized sections structures and cells that expressed Tratarate resistant acid phosphate, alkaline phosphatase, and osteopontin were identified by the use of markers. Results: The porosities of the TCP particles were initially filled with erythrocytes that subsequently were replaced with mineralized bone. Some of the graft material was invaded by mesenchymal and inflammatory cells and disintegrated. Thus, small membrane bound granules appeared in the granulation tissue and the provisional matrix. In the process of hard tissue formation, partly mineralized (modified) TCP particles became surrounded by ridges of woven bone. Conclusions: It was demonstrated that the early healing of an extraction socket that had been grafted with ,-TCP involved (i) the formation of a coagulum that was (ii) replaced with granulation tissue and a provisional matrix in which (iii) woven bone could form. In this process the biomaterial was apparently involved. To cite this article: Araújo MG, Liljenberg B, Lindhe J. ,-tricalcium phosphate in the early phase of socket healing: an experimental study in the dog. Clin. Oral Impl. Res. 21, 2010; 445,454. doi: 10.1111/j.1600-0501.2009.01876.x [source]

    Dental implants placement in conjunction with osteotome sinus floor elevation: a 12-year life-table analysis from a prospective study on 588 ITI®implants

    CLINICAL ORAL IMPLANTS RESEARCH, Issue 2 2006
    Nicola Ferrigno
    Abstract Objectives: The purpose of this prospective study was to evaluate the clinical success of placing ITI dental implants in the posterior maxilla using the osteotome technique. Material and methods: All implants were placed following a one-stage protocol (elevating the sinus floor and placing the implant at the same time). Five hundred and eighty-eight implants were placed in 323 consecutive patients with a residual vertical height of bone under the sinus ranging from 6 to 9 mm. The mean observation follow-up period was 59.7 months (with a range of 12,144 months). This prospective study not only calculated the 12-year cumulative survival and success rates for 588 implants by life-table analysis but also the cumulative success rates for implant subgroups divided per implant length and the percentage of sinus membrane perforation were evaluated. Results: The 12-year cumulative survival and success rates were 94.8% and 90.8%, respectively. The analysis of implant subgroups showed slightly more favourable cumulative success rates for 12 mm long implants (93.4%) compared with 10 and 8 mm long implants (90.5% and 88.9%, respectively). During the study period, only 13 perforations of the Schneiderian membrane were detected with a perforation rate of 2.2% (13 perforations/601 treated sites). Ten perforations out of 13 were caused during the first half of the study period and of these, seven were detected during the first 3 years of this prospective study. Conclusion: Based on the results and within the limits of the present study, it can be concluded that ITI implant placement in conjunction with osteotome sinus floor elevation represents a safe modality of treating the posterior maxilla in areas with reduced bone height subjacent to the sinus as survival and success rates were maintained above 90% for a mean observation period of ,60 months. Shorter implants (8 mm implants) did not significantly fail more than longer ones (10 and 12 mm implants): the differences were small compared with the number of events; hence, no statistical conclusion could be drawn. But, from the clinical point of view, the predictable use of short implants in conjunction with osteotome sinus floor elevation may reduce the indication for complex invasive procedures like sinus lift and bone grafting procedures. [source]

    A 7-year life table analysis from a prospective study on ITI implants with special emphasis on the use of short implants

    CLINICAL ORAL IMPLANTS RESEARCH, Issue 2 2004
    Results from a private practice
    Abstract: This paper reports on a 7-year life table analysis on ITI titanium plasma-sprayed (TPS) and sandblasted and etched (SLA) implants placed in a private practice and loaded for at least 1 year. In 236 patients, 528 (264 TPS and 264 SLA) implants were placed, 351 (66.5%) implants rehabilitated the posterior region and 71.1% implants were ,11 mm. In the posterior mandible and maxilla, the mean implant length was 9.90 and 9.74 mm respectively. Implant length was determined through standard radiographs only. Increase of the number of implants or reduction of the width or the length of the rehabilitations was not specifically sought for the shorter implants. One hundred and twenty-two SLA implants were loaded within 63 days. All early loaded SLA implants resisted the applied 35 N cm without rotation or pain. Three implants failed, one early and two late failures, all were SLA implants placed in the mandible. Shorter implants did not fail more than longer ones. The cumulative success rate was 99.40%. The predictable use of short implants supporting single crowns and small fixed partial dentures of 2,4 units supported by two to three implants permitted (1) restricting the need for sophisticated and expensive presurgical procedures aimed to determine precisely the available bone height by computerized radiographic methods, (2) the placement of prosthetically driven restoration instead of surgically driven ones, (3) reducing the indications span for complex invasive procedures like sinus lift and bone grafting procedures, (4) facilitating the surgery, without attempting to place the longest implant and (5) avoiding the occurrence of sensation disturbance. The safe use of short implants in a private practice should make implant therapy simpler and accessible to a higher number of patients and practitioners. Résumé Ce manuscript rapporte une analyse sur sept ans d'implants ITI® TPS et SLA placés dans un cabinet privé et chargés pendant au moins une année. Chez 236 patients, 528 implants (264 TPS et 264 SLA) ont été placés, 351 (66,5%) d'entre eux pour reconstruire la région postérieure et 71,1 étaient ,11 mm. Dans les parties postérieures de la mandibule et du maxillaire la longueur implantaire moyenne était respectivement de 9,90 et 9,74 mm. La longueur de l'implant était déterminée à partir uniquement de radiographies standards. L'augmentation du nombre d'implants ou la réduction de la largeur ou la longueur des reconstructions n'étaient pas spécifiquement recherchées pour les implants les plus courts. Cent vingt-deux implants SLA ont été mis en charge avant 63 jours. Tous les implants SLA avec mise en charge précoce ont resistéà la force de 35 Ncm appliquée sans rotation ni douleur. Trois implants ont échoué: 1) de manière précoce et 2) plus tard, tous étaient des implants SLA placés dans la mandibule. Les implants les plus courts n'avaient pas davantage d'échec que les plus longs. Le taux de succès cumulatif était de 99,40%. L'utilisation prévisible des implants courts portant des couronnes uniques et des petites prothèses fixées de deux à quatre unités supportées par deux à trois implants permettait 1) de réduire la nécessité de processus préchirurgicaux sophistiqué et cher visant ,a d"terminer précisemnentla hauteur osseuse disponible par des méthodes radiographiques avec ordinateur, 2) le placement de restaurations axées sur la prothèse plutôt que sur la chirurgie, 3) de diminuer la portée des indications des processus invasifs complexes comme l'épaississement du plancher buccal et les processus de greffe osseuse, 4) de faciliter la chirurgie sans essayer de placer l'implant le plus long, 5) d'éviter l'apparition de troubles de sensation. L'utilisation s,re d'implants court dans une pratique privée pourrait rendre la thérapie plus simple et accessible à un polus grand nombre de patients et de praticiens. Zusammenfassung Diese Arbeit berichtet über eine 7 Jahre Life Time Analyse von ITI TPS und SLA Implantaten, welche in einer Privatpraxis gesetzt wurden und für mindestens 1 Jahr unter Belastung standen. Bei 236 Patienten wurden 528 Implantate (264 TPS und 264 SLA) eingesetzt, 351 Implantate (66.5%) dienten der Wiederherstellung der posterioren Region und 71.1% der Implantate waren 11 mm lang. In der posterioren Mandibula bzw. Maxilla betrug die mittlere Implantatlänge 9.9 bzw. 9.74 mm. Die Implantatlänge wurde nur auf Standardröntgenbildern bestimmt. Bei Rekonstruktionen mit kurzen Implantaten wurden nicht speziell mehr Implantate verwendet oder die Breite oder die Länge der Rekonstruktionen reduziert. 122 SLA Implantate wurden innerhalb von 63 Tagen belastet. Alle frühbelasteten SLA Implantate widerstanden den applizierten 35Ncm ohne Rotation oder Schmerzen. 3 Implantate zeigten Misserfolge, einen Früh- und 2 Spätmisserfolge. Es handelte sich dabei ausschliesslich um SLA Implantate, welche im Unterkiefer eingesetzt worden waren. Kurze Implantate zeigten nicht mehr Misserfolge als lange. Die kumulative Erfolgsrate betrug 99.4%. Die Verwendung von kurzen Implantaten, welche Einzelkronen und kleine festsitzende Brücken mit 2,4 Einheiten auf 2,3 Implantanten trugen, erlaubte, 1) die Notwendigkeit von komplizierten und teuren prächirurgischen Abklärungen zur genauen Bestimmung der zur Verfügung stehenden Knochenhöhe durch computerisierte radiologische Methoden zu beschränken, 2) die Platzierung von prothetisch diktierten Rekonstruktionen anstelle von chirurgisch diktierten Rekonstruktionen, 3) eine Reduktion der Indikationsbreite von komplexen invasiven Prozeduren wie Sinuslift und Knochentransplantationen, 4) eine Erleichterung der Chirurgie indem nicht ein möglichst langes Implantat gesetzt werden musste, 5) das Auftreten von Sensibilitätsstörungen zu vermeiden. Die sichere Verwendung von kurzen Implantaten in einer Privatpraxis sollte die Implantattherapie einfacher machen. Dadurch sollte die Behandlung mit Implantaten einer grösseren Anzahl Patienten und Praktikern zugänglich werden. Resumen Este estudio informa sobre un análisis de un cuadro de vida de implantes ITI TPS y SLA colocados en una consulta privada y cargados durante al menos un año. Se colocaron 528 implantes (264 TPS y 264 SLA) en 236 pacientes, 351 implantes (66.5%) rehabilitaron el maxilar posterior y el 71.1% de los implantes fueron ,11 mm. La longitud media de los implantes en la mandíbula posterior y el maxilar fue de 9,90 y 9.74 mm respectivamente. La longitud del implante se determinó solamente a través de radiografías. No se buscaron específicamente incrementos en el número de implantes o reducción en la anchura o longitud de las rehabilitaciones para los implantes cortos. Se cargaron 122 implantes dentro de los 63 días. Todos los implantes SLA cargados tempranamente resistieron la fuerza de 35 Ncm aplicada sin rotación ni dolor. 3 implantes fracasaron, uno tempranamente y 2 tardíos, todos fueron implantes SLA colocados en la mandíbula. Los implantes mas cortos no fracasaron más que los implantes largos. El índice acumulativo de éxito fue del 99.4%. El uso predecible de implantes cortos soportando coronas unitarias y pequeñas prótesis fijas parciales de 2,4 unidades soportadas por 2,3 implantes permitieron, 1) restringir la necesidad de procedimientos quirúrgicos sofisticados y costosos con la intención de determinar con precisión la altura de hueso disponible por medio de métodos de radiografías computarizadas, 2) la colocación de restauraciones orientadas prosteticamente en vez de quirúrgicamente, 3) reducir el abanico de indicaciones para procedimientos complejos invasivos tales como procedimientos de elevación del seno e injertos, 4) facilitar la cirugía, sin intentar colocar el implante mas largo, 5) evitar la aparición de sensación de molestia. El uso seguro de implantes cortos en una consulta privada debería hacer el tratamiento de implantes mas simple y accesible para un mayor número de pacientes y profesionales. [source]