Graft Material (graft + material)

Distribution by Scientific Domains


Selected Abstracts


Iatrogenic Creutzfeldt,Jakob disease subsequent to dural graft: persisting risk after 1987

EUROPEAN JOURNAL OF NEUROLOGY, Issue 5 2003
C. Boutoleau
The first case of Creutzfeldt,Jakob disease (CJD) related to the use of a dura mater graft of cadaveric origin was identified in 1987 and this procedure is now considered as one of the main causes of iatrogenic CJD. Although the decontamination procedure for the preparation of graft material was modified, the product was withdrawn from the market in many countries a few years later and replaced by synthetic material. In this context, two patients treated in our institution developed CJD following a cadaveric dural graft performed after cerebral and lumbar trauma. Their clinical presentation, showing predominant cerebellar symptoms, late deterioration and myoclonic jerks, and a rapid disease course until death, was similar to that of previously reported cases involving the iatrogenic form. As the graft for one of the patients was performed in 1991 (several years after modification of the decontamination procedure), this fourth reported case suggests that the risk of iatrogenic CJD may have persisted in some patients treated after 1987, when grafts of cadaveric origin were totally abandoned. [source]


Bone regeneration in rabbit sinus lifting associated with bovine BMP

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2004
Sergio Allegrini Jr.
Abstract Autogenous bone is considered the optimal grafting material for sinus lifting, although its harvesting causes great patient discomfort. Various approaches have been taken in order to obtain sinus lifting with preexisting tissue. However, because of the unsuitability of such tissue, additional materials have been required. Alternatively, biomaterials from humans or other animals are used. In this study, the efficacy of using morphogenetic bovine bone protein (BMPb) to augment the maxillary sinus floor was examined. Four grafting materials were employed: lyophilized bovine bone powder, absorbable collagen flakes, natural hydroxylapatite, and synthetic hydroxylapatite. Two groups of rabbits were studied. In one group, graft material only was used. In the other, graft material was combined with 0.5 mg BMPb. During 8 weeks of observation, polyfluorochrome tracers were injected in subcutaneous tissue to evaluate new bone- deposition periods. Following sacrifice, the samples were examined under fluorescent and light microscopes. Results indicated 33.34% more newly formed bone in BMPb animals than in controls. Graft-material resorption increased, but natural HA showed no significant alterations. The results show that the use of BMPb, although providing osteoinduction, might not promote sufficient bone formation. Nonetheless, this material could provide an alternative to autogenous grafts, thereby avoiding patient discomfort. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 127,131, 2004 [source]


In vivo evaluation of hydroxyapatite foams

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 4 2002
P. Sepulveda
Abstract Hydroxyapatite (HA) is widely applied as bone graft material due to its osteoconductive potential and well-established biocompatibility. In this work, macroporous hydroxyapatite structures made through foaming of aqueous suspensions and gelcasting were tested for in vivo osteointegration. These foams are composed of a three-dimensional array of spherical pores with diameters of approximately 100,500 ,m, interconnected by windows of smaller size in the range of 30,120 ,m. The HA foams were implanted in the tibia of albino New Zealand rabbits and removed after a period of 8 weeks. Histological analysis revealed that the pores in the foams were partially or completely filled progressively with mature new bone tissue and osteoid after the implanted period. No immune or inflammatory reactions were detected. The high osteoconductive potential of the HA foams provides a potential structure for use as bone substitute in orthopedic, oral, and cranio-maxillofacial reconstructive surgery, and as dento-alveolar implants. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 587,592, 2002 [source]


Limitations of Right Internal Thoracic Artery to Left Anterior Descending Artery Bypass: A Comparative Quantitative Study of Postoperative Angiography of the Bilateral Internal Thoracic Artery Bypass Grafts

JOURNAL OF CARDIAC SURGERY, Issue 4 2008
Mizuho Imamaki M.D.
Methods: The 111 subjects underwent graft angiography after bypass grafting of the left or right internal thoracic artery (ITA) to the LAD. The vascular caliber was measured at the origin of the ITA, at an ITA site adjacent to the anastomotic site, and at an LAD site immediately below the anastomotic site, regarding the outer diameter of the catheter as a reference. Results: The caliber of the ITA immediately above the anastomotic site of the LAD was significantly lower in the RITA group. In the left internal thoracic artery (LITA) group, no patient showed a caliber of less than 1.25 mm, but five patients (7.8%) did in the RITA group. The preoperative cardio-thoracic ratio was significantly higher than that in patients in whom the caliber of the ITA immediately above the anastomotic site was 1.25 mm or more, and the height was significantly lower. Conclusions: In many patients, the RITA is appropriate as a graft material to the LAD. However, in patients with a high cardio-thoracic ratio and those with a low height, the RITA may not reach the LAD in a favorable state, and the LITA should be anastomosed to the LAD in some patients. [source]


Platelet-rich plasma may prevent titanium-mesh exposure in alveolar ridge augmentation with anorganic bovine bone

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2010
Jesús Torres
Torres J, Tamimi F, Alkhraisat MH, Manchón Á, Linares R, Prados-Frutos JC, Hernández G, López Cabarcos E. Platelet-rich plasma may prevent titanium-mesh exposure in alveolar ridge augmentation with anorganic bovine bone. J Clin Periodontol 2010; 37: 943,951. doi: 10.1111/j.1600-051X.2010.01615.x. Abstract Objective: Bone augmentation with the titanium-mesh (Ti-mesh) technique is susceptible to a large rate of complications such as morbidity of bone graft donor site, and mesh exposure to the oral cavity. The purpose of this study was to evaluate the effectiveness of anorganic bovine bone (ABB) in alveolar bone augmentation with the Ti-mesh technique. In addition, we investigated the effect of platelet-rich plasma (PRP) in preventing mesh exposure by using it to cover the Ti-mesh. Patients and Methods: Patients included in the clinical trial were randomly allocated by a blinded assistant into two groups. The 30 patients recruited for this study underwent 43 alveolar bone augmentation with the Ti-mesh technique using ABB as graft material in all of them. In 15 patients, the Ti-meshes were covered with PRP (PRP group) whereas in the other 15 the Ti-meshes were not (control group). After 6 months, patients were called for clinical, radiographic, and histological evaluation, and implant placement surgery. A total of 97 implants were placed in the augmented bone and their evolution was followed up for a period of 24 months. Results: Significant differences were found between the two study groups in terms of complications and bone formation. In the control group, 28.5% of the cases suffered from mesh exposure, while in the PRP group, no exposures were registered. Radiographic analysis revealed that bone augmentation was higher in the PRP group than in the control group. Overall, 97.3% of implants placed in the control group and 100% of those placed in the PRP group were successful during the monitoring period. We suggest that the positive effect of PRP on the Ti-mesh technique is due to its capacity to improve soft tissue healing, thereby protecting the mesh and graft material secured beneath the gingival tissues. Conclusions: Alveolar bone augmentation using ABB alone in the Ti-mesh technique is sufficient for implant rehabilitation. Besides, covering the Ti-meshes with PRP was a determining factor in avoiding mesh exposure. Ti-mesh exposure provoked significant bone loss, but in most cases it did not affect the subsequent placement of implants. [source]


Implants placed in combination with an internal sinus lift without graft material: an analysis of short-term failure

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2009
Olaf Gabbert
Abstract Aim: Investigation of the short-term survival of implants placed in combination with an internal sinus lift (ISL) without graft material. Material and Methods: Thirty-six patients received 92 screw-shaped dental implants in combination with an ISL. No bone grafts or bone substitutes were used. Forty-four patients with 77 implants in the native posterior maxilla served as controls. X-rays taken after implant placement and 6 months later were evaluated for the presence of bone gain at the apical aspect of the implants. Kaplan,Meier survival curves and Cox regression analysis were used to estimate survival curves and to isolate risk factors for implant failures. Results: Within a mean observation period of 1.2 years (minimum 9 months; maximum 3.7 years), four failures were recorded in the experimental group and two in the controls. The probability of survival was above 94% for both groups. Six,nine months after surgery, bone gain was observed in 29 out of 92 implants. Comparison of the experimental group and controls revealed no effect of ISL and membrane perforation on the probability of survival. Conclusions: Promising short-term outcomes were observed for implants with ISL without graft material; for a substantial proportion of implants, apical bone gain was observed in the first 6,9 months. [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]


Orthodontic movement in bone defects augmented with Bio-Oss®

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2001
An experimental study in dogs
Abstract Objective: To study if it was possible to move, by orthodontic means, a tooth into an area of the jaw that had been augmented with Bio-Oss®. Material and Methods: 5 beagle dogs were used. The 1st, 2nd, and 4th mandibular premolars on each side were removed. The defect at the left 4th premolar site was filled with a biomaterial (Bio-Oss®) while the corresponding defect in the right side was left for spontaneous healing. 3 months later, an orthodontic device was inserted in each side of the mandible. The device was designed to allow distal, bodily movement of the 3rd premolars. When the experimental teeth had been moved into the extraction sites of the 4th premolars, the animals were sacrificed and biopsies of the premolar-molar regions of the mandible sampled. The tissues were prepared for histological analysis using standard procedures. In the sections, 3 zones were identified: zone A=the bone tissue within the distal portion of the previous extraction site (4th premolar), zone B=the pressure side of the 3rd premolar, zone C=the tension side of the 3rd premolar. The area occupied by mineralized bone, Bio-Oss® particles and bone marrow was determined by a point counting procedure. The width of the periodontal ligament as well as the percentage of the root surface (in zone B) that exhibited resorption was determined. Results: The findings demonstrated that it was possible to move a tooth into an area of an alveolar ridge that 3 months previously had been augmented with a biomaterial. It was also demonstrated that 12 months after grafting, Bio-Oss® particles remained as inactive filler material in the not utilized part of zone A. The biomaterial was not present in zone C but present in small amounts in zone B. Conclusion: During the orthodontic tooth movement the graft material (Bio-Oss®) was degraded and eliminated from the part of the alveolar ridge that was utilized for the experiment. In the non-utilized part of the ridge the biomaterial, however, remained as a seemingly inactive filler material. [source]


Maxillary Sinus Elevation Surgery: An Overview

JOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 5 2003
ELIAZ KAUFMAN DDS
ABSTRACT Maxillary sinus elevation surgery was developed to increase the height of bone available for implant placement in the posterior maxilla. The efficacy and predictability of this procedure have been determined in numerous studies. The basic approach to the sinus (Caldwell-Luc operation) involves an osteotomy performed on the lateral maxillary wall, elevation of the sinus membrane, and placement of bone graft material. The graft materials can be categorized into four groups: autogenous bone, allografts (harvested from human cadavers), alloplasts (synthetic materials), and xenografts (grafts from a nonhuman species). These graft materials can be used alone or in combination with each other. Implant placement can occur at the same surgical procedure (immediate placement) or following a healing period of 6 to 9 months (delayed placement). A more conservative approach to the sinus, the osteotome technique, has been described as well. CLINICAL SIGNIFICANCE This article provides an overview of the surgical technique, with emphasis on anatomic considerations, preoperative patient evaluation (clinical and radiographic), indications and contraindications to the procedure, and possible risks and complications. [source]


Effect of freeze-drying and gamma irradiation on the mechanical properties of human cancellous bone

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2000
O. Cornu
Freeze-drying and gamma irradiation are commonly used for preservation and sterilization in bone banking. The cumulative effects of preparation and sterilization of cancellous graft material have not been adequately studied, despite the clinical importance of graft material in orthopaedic surgery. Taking benefit from the symmetry of the left and right femoral heads, the influence of lipid extraction followed by freeze-drying of a femoral head and a final 25-kGy gamma irradiation was determined, with the nonirradiated, nonprocessed counterpart as the control. Five hundred and fifty-six compression tests were performed (137 pairs for the first treatment and 141 pairs for the second). Mechanical tests were performed after 30 minutes of rehydration in saline solution. Freeze-dried femoral heads that had undergone lipid extraction experienced reductions of 18.9 and 20.2% in ultimate strength and stiffness, respectively. Unexpectedly, the work to failure did not decrease after this treatment. The addition of gamma irradiation resulted in a mean drop of 42.5% in ultimate strength. Stiffness of the processed bone was not modified by the final irradiation, with an insignificant drop of 24%, whereas work to failure was reduced by a mean of 71.8%. Freeze-dried bone was a bit less strong and stiff than its frozen control. Its work to failure was not reduced, due to more deformation in the nonlinear domain, and it was not brittle after 30 minutes of rehydration. Final irradiation of the freeze-dried bone weakened its mechanical resistance, namely by the loss of its capacity to absorb the energy (in a plastic way) and a subsequent greater brittleness. [source]


Cryopreserved iliac artery is indispensable interposition graft material for middle hepatic vein reconstruction of right liver grafts

LIVER TRANSPLANTATION, Issue 6 2005
Shin Hwang
Cryopreserved iliac vein grafts (IVGs) have often been used for reconstruction of middle hepatic vein (MHV) branches in right liver grafts, but their storage pool has often been exhausted in our institution due to the low incidence of deceased donor organ procurement. To overcome this shortage of IVG, we started to use cryopreserved iliac artery graft (IAG). During September and October 2004, we carried out 41 cases of adult living donor liver transplantation, including 29 right lobe grafts with MHV reconstruction. Interposition vessel grafts were autologous vein (n = 6), IVG (n = 13), and IAG (n = 10). IAG was used in 3 (21%) of 13 cases during the first month. For the next month, it was more frequently used (7 [44%] of 16) because handling of cryopreserved IAG was not difficult and its outcome was favorable. On follow-up with computed tomography for 3 months, outflow disturbance occurred in 1 (17%) of 6 autologous vein cases, in 2 (15%) of 13 IVG cases, and in 1 (10%) of 10 IAG cases. Two-month patency rate of IAG was not lower than that of IVG. In conclusion, we feel that cryopreserved IAG can be used as an interposition vessel graft for MHV reconstruction of right liver graft when cryopreserved IVG is not available. (Liver Transpl 2005;11:644,649.) [source]


Histological evaluation on bone regeneration of dental implant placement sites grafted with a self-setting ,-tricalcium phosphate cement

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 2 2008
Masayoshi Nakadate
Abstract This study aimed to evaluate the histological characteristics of the new bone formed at dental implant placement sites concomitantly grafted with a self-setting tricalcium phosphate cement (BIOPEX-R®). Standardized defects were created adjacent to the implants in maxillae of 4-week-old male Wistar rats, and were concomitantly filled with BIOPEX-R®. Osteogenesis was examined in two sites of extreme clinical relevance: (1) the BIOPEX-R®-grafted surface corresponding to the previous alveolar ridge (alveolar ridge area), and (2) the interface between the grafting material and implants (interface area). At the alveolar ridge area, many tartrate-resistant acid phosphatase (TRAPase)-reactive osteoclasts had accumulated on the BIOPEX-R® surface and were shown to migrate toward the implant. After that, alkaline phosphatase (ALPase)-positive osteoblasts deposited new bone matrix, demonstrating their coupling with osteoclasts. On the other hand, the interface area showed several osteoclasts initially invading the narrow gap between the implant and graft material. Again, ALPase-positive osteoblasts were shown to couple with osteoclasts, having deposited new bone matrix after bone resorption. Transmission electron microscopic observations revealed direct contact between the implant and the new bone at the interface area, although few thin cells could still be identified. At both the alveolar ridge and the interface areas, newly formed bone resembled compact bone histologically. Also, concentrations of Ca, P, and Mg were much alike with those of the preexistent cortical bone. In summary, when dental implant placement and grafting with BIOPEX-R® are done concomitantly, the result is a new bone that resembles compact bone, an ideal achievement in reconstructive procedures for dental implantology. Microsc. Res. Tech., 2008. © 2007 Wiley-Liss, Inc. [source]


Homologous Collagen Substances for Vocal Fold Augmentation

THE LARYNGOSCOPE, Issue 5 2001
Mark S. Courey MD
Abstract Objectives/Hypothesis Dysphonia resulting from failure of glottic closure during voicing is a difficult clinical problem. Recently developed homologous collagen compounds may be beneficial in treating this problem. The objectives of this thesis are to: 1) evaluate the potential site(s) of collagen graft placement in the human vocal fold, quantify the amount of graft material that can be injected into these sites, and determine how these sites are accessed by the currently available surgical tools for injection; 2) determine the effects of the superficial vocal fold implant on laryngeal vibratory patterns and characterize how the implant affects the forces required to bring vocal folds into an adducted position for vibration; and 3) evaluate the host response to two different forms of cadaveric collagen. Study Design Prospective laboratory. Methods Three separate experiments were undertaken: 1) Eight cadaver larynges were injected with collagen compounds through a 27-gauge needle. The amount of substance required to medialize the vocal fold and potential positions for graft placement were evaluated. 2) Six cadaver larynges were mounted on a stabilizing stand while airflow, vocal fold length, adduction forces, and abduction forces on the vocal folds were manipulated. Vibratory patterns before and after the injection of the vocal folds with solubilized collagen were assessed. 3) A nude mouse model was used to study the host response to two different exogenous collagen compounds. Results Solubilized collagen compounds could be injected reliably into the superficial layer of the lamina propria (SLLP), medial portion of the thyroarytenoid muscle, or lateral portion of the thyroarytenoid muscle. When injected superficially, significantly less material was required to displace the medial edge of the vocal fold to midline (P = .0001). When graft material was placed into the medial portion of the thyroarytenoid (TA) muscle, the forces required to bring the vocal fold into a position suitable for vibration were significantly reduced (P = .0106) and the vibratory patterns of the vocal folds were not impaired. Both AlloDerm® and Dermalogen® solubilized preparations of human dermal tissue were well tolerated in the nude-mouse model. Minimal inflammatory reaction occurred. Small amounts of graft material were identified histologically at the end of the 6-month study period. The graft material appeared organized and had been infiltrated with fibroblasts of host origin. Conclusions Homologous collagen compounds can be reliably injected into the cadaveric human larynx. When the substances are injected into the medial portion of the TA muscle, immediately deep to the vocal ligament, they decrease the force of contraction needed to bring the vocal folds into a position adequate for phonation and have minimal affect on the vibratory patterns. These forms of homologous collagen are well tolerated. A small amount persists over a 6-month interval. These materials warrant further clinical trials in human subjects. [source]


Augmentation of Exposed Implant Threads with Autogenous Bone Chips: Prospective Clinical Study

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 4 2000
Göran Widmark DDS
ABSTRACT Background: Autogenous bone chips can be harvested during drilling of implant sites and may be used as a graft material for bone augmentation and coverage of exposed implant threads. Purpose: The aim of this prospective study was to evaluate the possibility of augmenting exposed implant threads with autogenous bone chips. Materials and Methods: Twenty-one consecutive patients treated with screw-shaped oral implants with exposed threads due to buccal fenestration or marginal defects were augmented with autogenous bone harvested with a bone trap during drilling of the implant site. Both marginal (9 sites) and fenestration defects (12 sites), with 4 to 14 exposed implant threads, were registered clinically and with photography. The number of exposed implant threads was measured before and at second-stage surgery 6 months after augmentation. Results: Complete bone coverage of the exposed implant threads was seen in 12 of the 21 implant sites. Six sites showed one to two remaining exposed threads, two showed about 40% coverage, and one showed flattening of the defect but with eight of nine exposed threads at 6 months follow-up. The mean bone gain was 81% in patients with a marginal defect and 82% in patients with a fenestration defect. Conclusion: The results from this clinical study show that it is possible to gain bone over exposed implant threads by augmentation with autogenous bone chips. Conclusion It is concluded that it is possible to achieve coverage of exposed implant threads by augmentation with autogenous bone chips harvested during drilling of implant sites. [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]


A randomized-controlled clinical trial evaluating clinical and radiological outcomes after 3 and 5 years of dental implants placed in bone regenerated by means of GBR techniques with or without the addition of BMP-2

CLINICAL ORAL IMPLANTS RESEARCH, Issue 7 2009
Ronald E. Jung
Abstract Objective: The aim of this randomized-controlled clinical trial was to evaluate the long-term outcome of implants placed in bone augmented with a xenogenic bone substitute material and a collagen membrane with or without the addition of recombinant human bone morphogenetic protein-2 (rhBMP-2). Material and methods: Eleven patients received a total of 34 implants placed into sites exhibiting lateral bone defects. In a split mouth design, the defects were randomly treated with the graft material and the collagen membrane either with (test) or without (control) rhBMP-2. The patients were examined 3 and 5 years after insertion of the prosthetic restoration. Student's paired t -test was performed to detect differences between the two groups. Results: The survival rate at 3 and 5 years was 100% for both groups. The peri-implant soft tissues were stable and healthy without any difference between the two groups. The prosthetic reevaluation demonstrated four loose prosthetic screws during the first 3 years and seven ceramic chippings after 3 and 5 years. The mean distance between the first bone to implant contact to implant abutment junction at 3 years was 1.37 mm (test), 1.22 mm (control), and 1.38 mm (test), and 1.23 mm (control) at 5 years. The difference of <0.2 mm between test and control implants was not statistically significant. The mean change of the marginal bone level between baseline and 5 years ranged from ,0.07 mm (mesial, test), ,0.11 mm (distal, test), ,0.03 mm (mesial, control), to +0.13 mm (distal, control). No statistically significant differences were observed between test and control sites. Conclusion: Implants placed in bone augmented with and without rhBMP-2 revealed excellent clinical and radiological outcomes after 3 and 5 years. [source]


Back-scattered electron imaging and elemental microanalysis of retrieved bone tissue following maxillary sinus floor augmentation with calcium sulphate

CLINICAL ORAL IMPLANTS RESEARCH, Issue 8 2008
Nicola Slater
Abstract Objectives: To investigate the presence and composition of residual bone graft substitute material in bone biopsies from the maxillary sinus of human subjects, following augmentation with calcium sulphate (CaS). Material and methods: Bone cores were harvested from the maxillary sinus of patients who had undergone a sinus lift procedure using CaS G170 granules 4 months after the initial surgery. Samples from seven patients, which contained residual biomaterial particles, were examined by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy was used to determine the composition of the remaining bone graft substitute material. Results: Residual graft material occurred in isolated areas surrounded by bone and consisted of individual particles up to 1 mm in length and smaller spherical granules. On the basis of 187 separate point analyses, the residual material was divided into three categories (A, B and C) consisting of: A, mainly CaS (S/P atomic% ratio ,2.41); B, a heterogeneous mixture of CaS and calcium phosphate (S/P=0.11,2.4) and C, mainly calcium phosphate (S/P,0.11; C), which had a mean Ca : P ratio of 1.63±0.2, consistent with Ca-deficient hydroxyapatite. Linescans and elemental maps showed that type C material was present in areas which appeared dense and surrounded, or were adjacent to, more granular CaS-containing material, and also occurred as spherical particles. The latter could be disintegrating calcium phosphate in the final stages of the resorption process. Conclusions: CaS resorption in the human maxillary sinus is accompanied by CaP precipitation which may contribute to its biocompatibility and rapid replacement by bone. [source]


Injectable calcium phosphate cement as a graft material for maxillary sinus augmentation: an experimental pilot study

CLINICAL ORAL IMPLANTS RESEARCH, Issue 6 2008
Ali Aral
Abstract Objectives: The aim of the present study was to evaluate the efficiency of injectable CaP cement as a graft material around dental implants in the maxillary sinus augmentation procedure. Material and methods: Bilateral sinus augmentation process was carried out in three sheep and two implants were inserted during the same session. Out of a total of 12 installed implants, eight belonged to the so-called experimental group. In the experimental group, injectable CaP cement was used as augmentation material while autologous bone served as control. Results: Histological examination revealed that newly formed bone surrounded the cement completely without an intervening fibrous tissue layer. Following a healing period of 12 weeks, mean bone-to-implant contact (BIC) values in the experimental and control groups were 36±5 and 37±3, respectively. The percentage of BIC was comparable with other experimental sinus augmentation studies. Further, it appeared that the thickness of the cortical bone that covered the outer surface of the maxillary sinus was <2,3 mm, which affected the primary stability of the implants negatively. Conclusion: CaP cement is indeed effective to stimulate bone formation in the sinus elevation procedure. Nevertheless, additional improvements in the cement composition are required to allow final clinical utilization of the material. [source]


Evaluation of a novel biphasic calcium phosphate in standardized bone defects.

CLINICAL ORAL IMPLANTS RESEARCH, Issue 6 2007
A histologic, histomorphometric study in the mandibles of minipigs
Abstract: Objective: A novel biphasic calcium phosphate (CaP) granulate consisting of hydroxyapatite (HA) and ,-tricalciumphosphate (TCP) was compared with pure HA and pure TCP and with autograft as positive control. Materials and methods: Four standardized bone defects were prepared in both mandibular angles of 16 minipigs and grafted with autogenous bone chips, HA, HA/TCP (60% : 40%), or TCP. Histologic and histomorphometric analysis of bone formation and graft degradation followed healing periods of 2, 4, 8, and 24 weeks. Results: 2 weeks: more bone formation in defects filled with autograft than with the three CaP materials (P<0.05). 4 weeks: bone formation differed significantly (P<0.05) between all four materials (autograft>TCP>HA/TCP>HA). 8 weeks: more bone formation in defects with autograft and TCP than with HA/TCP (P<0.05), and HA/TCP had more bone formation than HA (P<0.05). 24 weeks: no difference in bone formation between the groups. Autograft and TCP resorbed quickly and almost completely over 8 weeks, whereas HA/TCP and HA showed limited degradation over 24 weeks. Conclusion: All defects healed with mature lamellar bone and intimate contact between bone and the remaining graft material. The rate of bone formation corresponded to the content of TCP in the CaP materials. [source]


Osseointegration of Osseotite® and machined-surfaced titanium implants in membrane-covered critical-sized defects: a histologic and histometric study in dogs

CLINICAL ORAL IMPLANTS RESEARCH, Issue 2 2007
Alexander A. Veis
Abstract: The texture of an implant's surface can influence the rate and extent of bone fixation as expressed by the amount of linear bone-to-implant contact (BIC). The purpose of this study was to compare the bone density and linear BIC between Osseotite® and machined-surface implants placed in bony defects without graft material and covered by a membrane. Thirty 2 mm diameter, 10 mm length custom implants were prepared for this study having a ,split surface,' with one side having the acid-etched surface and the opposite side having a machined surface. Defects were created in the iliac wing of three adult mongrel dogs where a 6-mm-diameter drill was used to generate a 5-mm-deep defect. The implants were inserted into the center of the defect with 5 mm secured into the bone leaving 5 mm free in the defect with a 2 mm gap between the implant and surrounding bone. Expanded polytetrafluroethelyene membranes were placed over the defect sites stabilized with Biotack® pins. The healing times were 2, 3, and 5 months. Histologic and histometric analysis showed significantly lower BIC in the defect region as compared with the portion of implant placed into native bone for both implant surfaces in all groups. There was no difference in BIC values at 2- and 5-month periods between the two surfaces in the regenerated area, while BIC values for Osseotite® surfaces were significantly higher than the machined surfaces at 3 months' healing time. Changes in bone density, observed between the three groups, affected correspondingly the BIC values in both implant surfaces, the effect being more pronounced in the Osseotite® surface. [source]


Maxillary Sinus Elevation Surgery: An Overview

JOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 5 2003
ELIAZ KAUFMAN DDS
ABSTRACT Maxillary sinus elevation surgery was developed to increase the height of bone available for implant placement in the posterior maxilla. The efficacy and predictability of this procedure have been determined in numerous studies. The basic approach to the sinus (Caldwell-Luc operation) involves an osteotomy performed on the lateral maxillary wall, elevation of the sinus membrane, and placement of bone graft material. The graft materials can be categorized into four groups: autogenous bone, allografts (harvested from human cadavers), alloplasts (synthetic materials), and xenografts (grafts from a nonhuman species). These graft materials can be used alone or in combination with each other. Implant placement can occur at the same surgical procedure (immediate placement) or following a healing period of 6 to 9 months (delayed placement). A more conservative approach to the sinus, the osteotome technique, has been described as well. CLINICAL SIGNIFICANCE This article provides an overview of the surgical technique, with emphasis on anatomic considerations, preoperative patient evaluation (clinical and radiographic), indications and contraindications to the procedure, and possible risks and complications. [source]


Biomechanical findings in rats undergoing fascial reconstruction with graft materials suggested as an alternative to polypropylene ,,

NEUROUROLOGY AND URODYNAMICS, Issue 3 2010
M.L. Konstantinovic
Abstract Aims Graft materials used for pelvic floor reinforcement should still be considered as investigational and, therefore, evaluated experimentally and within clinical trials. The present report describes our biomechanical findings in rats implanted with selected novel implant materials, which in recent years have been suggested as alternatives to plain polypropylene (PP) meshes. Methods Full thickness abdominal wall defects were primarily repaired by the implant of interest. Experiments involved eight different implant materials: two partly degradable synthetic implants, that is, a hybrid of polyglactin 910 with PP (Vypro II) and collagen coated PP (Pelvitex); two non-cross linked (Surgisis, InteX,n LP) and two cross-linked materials (Pelvicol, Pelvisoft) and two porous modifications of InteX,n LP and Pelvicol implants. At different time points (7, 14, 30, and 90 days), the implants and surrounding host tissue (explant) were harvested and tensiometry was performed. Tensile strength and location of breakage were recorded. Results In general resorbable non-cross linked collagen matrices and porous materials were weaker after 90 days; similar behavior was seen for implant materials alone and their construction with the surrounding native tissue. Both non-porous and porous modification of InteX,n LP appeared at 90 days as a very thin layer of collagen that was two-thirds, respectively one-third of the initial thickness. Conclusions In experimental conditions, sufficient strength was obtained only after 3 months, and PP containing constructs appeared as the strongest though reconstruction with Pelvicol showed comparable outcomes. Lower values for strength of non-cross linked and porous collagen materials are questioning their efficacy for pelvic floor reconstruction. Neurourol. Urodynam. 29:488,493, 2010. © 2009 Wiley-Liss, Inc. [source]


Time- and dose-dependent mitogenic effect of basic fibroblast growth factor combined with different bone graft materials: an in vitro study

CLINICAL ORAL IMPLANTS RESEARCH, Issue 5 2006
Xanthippi E. Dereka
Abstract Objectives: In periodontal regeneration, the growth factor concentrations and the delivery system used are of great importance. In an attempt to assess the mitogenic effect of basic fibroblast growth factor (bFGF) on periodontal ligament (PDL) cells combined with different bone replacement materials, two allografts of cortical (DFDBA) and cancellous (DFBA) bone and an anorganic bovine material with a synthetic peptide (ABM P-15) were used. The purpose of this study was to evaluate the in vitro mitogenic effect of different doses of bFGF alone or in combination with DFDBA, DFBA and ABM P-15 on human PDL cells in a time-dependent mode. Material and methods: PDL cell cultures were derived from the mid-root of four maxillary premolars. Cells were grown and reached confluence. On day 2 of quiescence, new medium was added along with (1) 1, 5, 10 and 25 ng/ml of bFGF alone, (2) 10 mg of DFDBA, DFBA and ABM P-15 alone and (3) their combination. The mitogenic effect was determined at 24 and 48 h of culture by using a hemocytometer chamber. The cells were counted under a phase contrast microscope. Results: The results revealed that bFGF at the highest concentrations and after 48 h exerted a significant mitogenic effect on PDL cells, and also DFDBA and DFBA supported cell proliferation. Furthermore, DFDBA and DFBA enriched with bFGF had a significant mitogenic effect after 48 h of culture. ABM P-15 with 10 and 25 ng/ml of bFGF up-regulated PDL cell proliferation after 48 h of incubation. Conclusions: The findings of this study demonstrate the beneficial role of bFGF combined with DFDBA and DFBA as carriers in periodontal repair. [source]


Tissue-engineered injectable bone regeneration for osseointegrated dental implants

CLINICAL ORAL IMPLANTS RESEARCH, Issue 5 2004
Yoichi Yamada
Abstract: The present study investigated a correlation between osseointegration in dental implants and an injectable tissue-engineered bone, using mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP). Initially, the teeth in the mandible region were extracted and the healing period was 1 month. Bone defects on both sides of the mandible were prepared with a trephine bar. The defects were implanted with graft materials as follows: PRP, dog MSCs (dMSCs), and PRP, autogenous particulate cancellous bone and marrow (PCBM), and control (defect only). Two months later, the animals were evaluated by histology, and at the same time dental implants were installed. Two months later, the animals were sacrificed and nondecalcified sections were evaluated histologically and histometrically. According to the histological observations, the dMSCs/PRP group had well-formed mature bone and neovascularization, compared with the control (defect only) and PRP groups, as was the same for the PCBM group. A higher marginal bone level was observed around implants with PRP, PCBM, and dMSCs/PRP compared with the control. Furthermore, the values describing the amount of bone,implant contact (BIC) at the bone/implant interface were significantly different between the PRP, PCBM, dMSCs/PRP, and control groups. Significant differences were also found between the dMSCs/PRP and control groups in bone density. The findings of this experimental study indicate that the use of a mixture of dMSCs/PRP results in good results such as the amount of BIC and bone density comparable with that achieved by PCBM. Résumé L'étude présente a analysé une corrélation entre l'ostéïntégration d'implants dentaires et un os injectable traité en utilisant des cellules souches mésenchymateuses (MSC) et du plasma riche en plaquette (PRP). Initialement, les dents de la région mandibulaire ont été avulsées et la période de guérison a été d'un mois. Les lésions osseuses des deux côtés de la mandibule ont été préparées avec un trépan. Les lésions ont été traitées avec les matériaux de greffe suivants : PRP, MSC canin (dMSC) et PRP, moelle l'os spongieux en petites particules autogènes (PCBM) et contrôle (lésion seulement). Deux mois plus tard, les animaux ont étéévalués et en même temps les implants dentaires ont été placés. Deux mois plus tard, les animaux ont été euthanasiés et des coupes non-décalcifiées ont étéévaluées histologiquement et histométriquement. Suivant les observations histologiques, le groupe dMSC/PRP avait de l'os mûr bien formé et une néovascularisation comparé au contrôle et aux groupes PRP, comme pour le groupe PCBM. Un niveau osseux marginal plus important a été observé autour des implants avec PRP, PCBM et dMSC/PRP comparé au contrôle. De plus les valeurs décrivant la quantité de contact os/implant à l'interface os/implant étaient significativement différentes entre les groupes PRP, PCBM, dMSC/PRP et contrôles. Des différences significatives étaient aussi trouvées entre les groupes dMSC/PRP et contrôle en ce qui concernait la densité osseuse. Ces découvertes indiquent que l'utilisation d'un mélange dMSC/PRP résulte en de bons résultats tels que la quantité de contact os-implant et la densité osseuse comparéà ce qui se passe après l'utilisation du PCBM. Zusammenfassung Gewebemanipulierte injizierbare Knochenregenerate für osseointegrierte dentale Implantate Die vorliegende Studie untersuchte eine Korrelation zwischen der Osseointegration bei dentalen Implantaten und einem injizierbaren gewebemanipulierten Knochenregenerat aus mesenchymalen Stammzellen (MSCs) und plättchenreichem Plasma (PRP). Zuerst wurden die Zähne im Unterkiefer extrahiert. Darauf folgte eine Heilungsperiode von 1 Monat. Auf beiden Seiten der Unterkiefer wurden mit einer Hohlfräse Knochendefekte präpariert. Die Defekte wurden mit folgenden Transplantatmaterialien aufgefüllt: PRP, Hunde MSCs (dMSCs) und PRP, autologer zerkleinerter Knochen und Knochenmark (PCBM) und kein Füllmaterial (Kontrolle). Zwei Monate später wurden die Tiere histologisch untersucht und es wurden dentale Implantate eingesetzt. Nach weiteren zwei Monaten wurden die Tiere geopfert und nicht entkalkte Schnitte wurden histologisch und histometrisch ausgewertet. Gemäss der histologischen Beobachtungen zeigten die dMSCs/PRP Gruppe im Vergleich zur Kontrollgruppe und zur PRP Gruppe gut ausgebildeten reifen Knochen und neue Gefässe. Das Selbe galt für die PCBM Gruppe. Bei den Implantaten mit PRP, PCBM und dMSCs/PRP konnte im Vergleich zur Kontrollgruppe ein höheres marginales Knocheniveau beobachtet werden. Zudem waren die Werte, welche das Ausmass an Knochen-Implantat-Kontakt an der Kochen/Implantat Berührungsfläche beschreiben, zwischen den PRP, PCBM, dMSCs/PRP und der Kontrollgruppe signifikant verschieden. Signifikante Unterschiede wurden auch bezüglich Knochendichte zwischen der dMSCs/PRP und der Kontrollgruppe gefunden. Die Ergebnisse dieser experimentellen Studie zeigen, dass die Anwendung eines Gemisches aus dMSCs/PRP zu guten Resultaten bezüglich Ausmass an Knochen-Implantat-Kontakt und Knochendichte führt. Die erzielten Resultate sind mit den mit PCBM erreichten vergleichbar. Resumen El presente estudio investigó la correlación entre osteointegración en implantes dentales y un tejido-elaborado óseo inyectable, usando células madre mesenquimales (MSCs) y plasma rico en plaquetas (PRP). Inicialmente, se extrajeron los dientes de la mandíbula y el periodo de cicatrización fue de un mes. Se prepararon defectos óseos en ambos lados de la mandíbula con una fresa trépano. Los defectos se implantaron con material de injerto de la siguiente manera: PRP, MSCs de perro (dMSCs) y PRP, partículas de hueso esponjoso y médula autógenos (PCBM), y control (defecto solo). Dos meses mas tarde, los animales se evaluaron por histología, al mismo tiempo se instalaron implantes dentales. Dos meses mas tarde se sacrificaron los animales y se evaluaron secciones no descalcificadas histológica e histometricamente. De acuerdo con las observaciones histológicas, el grupo dMSCs/PRP había formado bien un hueso maduro y una neovascularización, comparado con el control (defecto solo) y grupos PRP, también fue igual para el grupo PCBM. Se observó un nivel óseo marginal mas alto alrededor de los implantes con PRP, PCBM, y dMSCs/PRP comparados con el control. Mas aun, los valores que describen la cantidad de contacto hueso-implante en la interfase hueso/implante fueron significativamente diferentes entre los grupos PRP, PCBM, dMSCs/PRP, y de control en la densidad ósea. Estos hallazgos de este estudio experimental indican que el uso de una mezcla de dMSCs/PRP resulta en buenos resultados tales como la cantidad de contacto hueso-implante y densidad ósea comparable a aquella lograda por PCBM. [source]