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Graft Resorption (graft + resorption)

Distribution by Scientific Domains

Medical Sciences	71%

Selected Abstracts

Bone replacement following dental trauma prior to implant surgery , present status

DENTAL TRAUMATOLOGY, Issue 1 2009
Mats Hallman
Although autogenous bone grafts is considered the ,gold standard', this may be associated with patient morbidity and graft resorption. Consequently, the use of bone substitutes has increased. Today, a substantial number of biomaterials are available on the market, but only a few are well documented. The user should be aware that these biomaterials have different properties: resorbable or non-resorbable, time of resorption and resorption mechanism. The purpose of this review is to describe the function of various bone substitutes and indications for their use in reconstructive implant surgery and to give an overview of the current situation. [source]

The use of OP-1 in femoral impaction grafting in a sheep model

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2004
Margaret A. McGee
Abstract The aim of this pilot study was to examine bone graft incorporation in femurs impacted with allograft bone alone (control group) or with allograft containing the bone morphogenetic protein OP-1 (BMP-7) (OP-1 group) in a sheep model of cemented hemiar-throplasty. Two sheep in each group were sacrificed at 6, 18 and 26 weeks. Successful bone graft incorporation was evident in both groups by six weeks but in the OP-1 group, there had been more extensive resorption of the graft. There was one case of excessive stem subsidence in the OP-1 group at six weeks. By 18 weeks, there was remodelling and trabeculation of the new bone in the OP-1 group, but this appeared less advanced in the control group. By 26 weeks, there was remodelling of bone in the graft bed. The results of this small study suggest that OP-1 promotes initial graft resorption, thus hastening bone graft incorporation and remodelling in femoral impaction grafting. The one case of stem subsidence may be associated with the early resorption seen in the OP-1 group and reinforces the need for further studies, examining dose response and using precise measures of stem movement, before this BMP is used in femoral impaction grafting at revision hip arthroplasty. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source]

A resorbable porous ceramic composite bone graft substitute in a rabbit metaphyseal defect model

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2003
W. R. Walsh
The success of converted corals as a bone graft substitute relies on a complex sequence of events of vascular ingrowth, differentiation of osteoprogenitor cells, bone remodeling and graft resorption occurring together with host bone ingrowth into and onto the porous coralline microstructure or voids left behind during resorption. This study examined the resorption rates and bone infiltration into a family of resorbable porous ceramic placed bilaterally in critical sized defects in the tibial metaphyseal,diaphyseal of rabbits. The ceramics are made resorbable by partially converting the calcium carbonate of corals to form a hydroxyapatite (HA) layer on all surfaces. Attempts have been made to control the resorption rate of the implant by varying the HA thickness. New bone was observed at the periosteal and endosteal cortices, which flowed into the centre of the defect supporting the osteoconductive nature of partially converted corals. The combination of an HA layer and calcium carbonate core provides a composite bone graft substitute for new tissue integration. The HA-calcium carbonate composite demonstrated an initial resorption of the inner calcium carbonate phase but the overall implant resorption and bone ingrowth behaviour did not differ with HA thickness. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source]

Combined use of crushed cartilage and processed fascia lata for dorsal augmentation in rhinoplasty for Asians

THE LARYNGOSCOPE, Issue 6 2009
Yong Ju Jang MD
Abstract Objectives/Hypothesis: Autologous dorsal nasal grafts have limitations including limited tissue availability, additional surgery time, donor site morbidity, a visible graft contour, and postoperative distortions and deformities owing to displacement and warping. This report describes our experience using combined Tutoplast-processed fascia lata (TPFL) and crushed cartilage for dorsal augmentation and contouring in rhinoplasty. Study Design: A retrospective clinical chart review. Methods: The study involved a total of 113 patients (68 male, 45 female), who underwent crushed cartilage-TPFL grafting to the nasal dorsum. Patient satisfaction was evaluated using a questionnaire. Photographs and postoperative histories were reviewed to assess complications including graft resorption, graft infection, warping, extrusion, irregularity, and postoperative deformity. Results: Different autologous grafts were used in combination with TPFL: septal cartilage in 70 cases (61.9%), septal cartilage and ethmoid bone in 17 cases (15.0%), costal cartilage in 15 cases (13.3%), and septal and conchal cartilage in 11 cases (9.7%). Of the 101 patients who responded to the questionnaire, 85.1% were satisfied with the surgical outcome. Complications were encountered in four patients (3.5%), comprising overcorrected dorsal augmentation in two patients, graft resorption in one patient, and dorsal irregularity in one patient. Eight patients (7.1%) required revision rhinoplasty due to dissatisfaction with the nasal tip shape (n = 6), graft resorption (n = 1) and overcorrected dorsal augmentation (n = 1). Conclusions: The combined use of crushed cartilage and TPFL appears to be a useful technique for dorsal augmentation and contouring. This technique provides favorable and predictable outcomes in rhinoplasty. Laryngoscope, 2009 [source]

Effects of a Mechanical Barrier on the Integration of Cortical Onlay Bone Grafts Placed Simultaneously with Endosseous Implant

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2002
Luiz Z. Salata DDS
ABSTRACT Background: Previous experimental studies on onlay bone graft integration have shown either advantages or disadvantages to the use of mechanical barriers. This indicates that the role played by the biologic properties of transplanted bone and membrane in graft revascularization and bone remodeling has not yet been established. The outcomes regarding osseointegration of titanium dental implants applied in such a condition are still contradictory. Purpose: The rabbit's radius model that is grafted onto the mandibular lower border and covered by membrane can reproduce a challenging experimental situation to preliminarily study the factors involved in osseointegration under deprived blood vessels source. Materials and Methods: Fourteen New Zealand White rabbits had a 2.5-cm segment of the right radius osteoectomized and fixed onto the right mandibular lower border using titanium screws. Two screw-shaped titanium implants (2.5 mm wide 2.5 mm long) were installed 7 mm apart in the mid length of the grafted bone. In experimental sites, the graft with the implants and graft-host bone junction were covered by expanded polytetrafluoroethylene (e-PTFE) membrane; control sites were left uncovered. Eight animals from the experimental group and six animals from the control group were sacrificed at 6 and 24 weeks after surgery. Ground sections obtained from en bloc tissues containing graft, implants, and recipient bone were subjected to histologic evaluation and histomorphometric analysis (area occupied by the graft and bone-to-implant contact). Results: The graft showed significantly more resorption after 24 weeks than at 6 weeks (p .05) irrespective of the treatment (with or without membrane), although the amount of new bone was greater at 24 weeks in sites where a membrane was covering the graft. Compared with 6 weeks postoperatively, the bone-to-implant contact was considerably improved at 24 weeks (p .05), and the membrane seemed beneficial for implant osseointegration when compared with unprotected sites (p .05). As a result of graft resorption, the amount of soft tissue was considerably expanded in sites beneath membrane, accompanied by a sustained process of trabecular bone deposition close to the barrier. Conclusions: Cortical onlay grafts covered by membrane demonstrated delayed remodeling, probably as a consequence of a hindered process of graft revascularization. Grafts covered by membrane might rely on previous host bone resorption both to become revascularized and to remodel. The findings that the membrane-protected grafts were most resorbed at 24 weeks might be attributable to better implant osseointegration, because the fixtures were exposed to greater mechanical stimulation in these sites. [source]

Bone healing and graft resorption of autograft, anorganic bovine bone and ,-tricalcium phosphate.

CLINICAL ORAL IMPLANTS RESEARCH, Issue 3 2006
A histologic, histomorphometric study in the mandibles of minipigs
Abstract Objective: The purpose was to qualitatively and quantitatively compare the bone formation and graft resorption of two different bone substitutes used in both orthopedic and oral surgery, with autogenous bone as a positive control. Materials and methods: Three standardized bone defects were prepared in both mandibular angles of 12 adult minipigs. The defects were grafted with either autograft, anorganic bovine bone (ABB), or synthetic ,-tricalcium phosphate (,-TCP). Sacrifice was performed after 1, 2, 4, and 8 weeks for histologic and histomorphometric analysis. Results: At 2 weeks, more new bone formation was seen in defects filled with autograft than with ABB (P,0.0005) and ,-TCP (P,0.002). After 4 weeks, there was no significant difference between ,-TCP and the two other materials. Defects grafted with ABB still exhibited less bone formation as compared with autograft (P,0.004). At 8 weeks, more bone formation was observed in defects grafted with autograft (P,0.003) and ,-TCP (P,0.00004) than with ABB. No difference could be demonstrated between ,-TCP and autograft. ,-TCP resorbed almost completely over 8 weeks, whereas ABB remained stable. Conclusion: Both bone substitutes seemed to decelerate bone regeneration in the early healing phase as compared with autograft. All defects ultimately regenerated with newly formed bone and a developing bone marrow. The grafting materials showed complete osseous integration. Both bone substitutes may have a place in reconstructive surgery where different clinical indications require differences in biodegradability. [source]