Edward Ahn - Profile on Academia.edu (original) (raw)

Papers by Edward Ahn

Matrice continue dans laquelle des particules ostéoconductrices sont dispersées, procédé de formation de cette matrice et procédé de régénération osseuse à l'aide de cette matrice

La presente invention concerne des compositions utiles pour regenerer un tissu conjonctif, en par... more La presente invention concerne des compositions utiles pour regenerer un tissu conjonctif, en particulier un os. Les compositions comprennent une matrice continue formee a partir d'un polypeptide reticule a un second polymere, des particules de materiau poreux osteoconducteur etant dispersees dans la matrice continue. La composition peut etre fournie sous forme deshydratee. L'invention concerne en outre des procedes de preparation de la composition sous une formule utile en clinique, des procedes d'utilisation de la composition pour regenerer des os et des kits contenant la composition.

Phosphates tricalciques et leur composites, implants incorporation lesdits phosphates et leurs procedes de production

L'invention concerne des procedes permettant d'effectuer la synthese de phosphates trical... more L'invention concerne des procedes permettant d'effectuer la synthese de phosphates tricalciques, ainsi qu'une serie de parametres de reaction specifiques pouvant etre regles afin de personnaliser, de maniere specifique, des proprietes dans le precipite precurseur de phosphate de tricalcique. L'invention concerne egalement des compositions particulaires de phosphate tricalcique possedant une taille moyenne de cristal d'environ 250 nm ou moins. Les compositions de l'invention peuvent etre utilisees comme implants prothetiques et revetement d'implants prothetiques.

Injectable Fillers for Aesthetic Medical Enhancement and for Therapeutic Applications

Nanocrystalline apatites and composites, prostheses incorporating them, and methods of their production

Fusion Device, Systems and Methods Thereof

Cement products and methods of making and using the same

Tricalcium Phosphates, Their Composites, Implants Incorporating Them, and Methods for Their Production

Continuous Matrix with Osteoconductive Particles Dispersed Therein, Method of Forming Thereof, and Method of Regenerating Bone Therewith

Technologies for Use in Indirect Distraction Procedures

Minimally Invasive Spine Surgery, 2009

Osteoporosis results in the thinning of the cortical shell and trabecular struts of the bones suc... more Osteoporosis results in the thinning of the cortical shell and trabecular struts of the bones such that the loads of normal daily activities can result in fractures.In the case of osteoporosis of the vertebrae, vertebral compression fractures (VCF) can occur spontaneously or as the result of a low-energy trauma, resulting in chronic pain and reduced mobility [1]. If left untreated,

Nanocrystalline apatites and composites, prostheses incorporating them, and method for their production

Nano Letters, 2001

Nanostructure processing was applied to derive hydroxyapatite and hydroxyapatite-zirconia biocera... more Nanostructure processing was applied to derive hydroxyapatite and hydroxyapatite-zirconia bioceramics with ultrafine microstructures and significantly improved mechanical properties for orthopedic and dental implant applications. Despite its attractive bioactivity, hydroxyapatite (HAP) has been limited in applications due to the poor processability and mechanical strength of the conventional material. Through nanostructure processing, high-strength HAP has been obtained by pressure-assisted sintering. To further toughen the HAP matrix, nanocrystalline yttriastabilized zirconia (YSZ) dispersoids have been introduced during HAP precipitation. The nanostructured HAP and HAP-YSZ composites demonstrated excellent chemical and microstructural uniformity and mechanical properties, compared to conventional coarse-grained systems.

Journal of the American Ceramic Society, 2005

A hydrothermally treated zirconia colloid was introduced during the precipitation of hydroxyapati... more A hydrothermally treated zirconia colloid was introduced during the precipitation of hydroxyapatite (HAP) to achieve an HAPzirconia nanocomposite. High dispersion of zirconia was achieved at zirconia loadings below 8 wt%. Vickers hardness was optimized with a 1.5 wt% loading of zirconia. A low loading (1.5 wt%) of tetragonal zirconia was able to increase the bending strength of nanocrystalline HAP from 183 to 243 MPa. This HAP-zirconia nanocomposite was sintered to full density by 10001C under an applied load of 50 MPa. The average grain sizes of HAP and zirconia were maintained at r100 nm. With the high strength and low loading of secondary phase, these HAP-based nanocomposites should be attractive for orthopedic and dental implant applications.

Bone Graft Materials: A Comparison of Nanoss Bioactive 3d and Vitoss Ba in a Challenging Model

Introduction The need for regeneration and repair of bone presents itself in a variety of clinica... more Introduction The need for regeneration and repair of bone presents itself in a variety of clinical situations. The current gold standard of treatment is autograft harvested from the iliac crest or local bone. Inherent disadvantages associated with the use of autogenous bone include limited supply, increased operating time and donor site morbidity. This study utilized a challenging model of posterolateral fusion to evaluate the in vivo response of an engineered collagen carrier combined with nano-structured hydroxyapatite (NanOss Bioactive 3D, Pioneer Surgical) compared to a collagen porous beta-tricalcium phosphate bone void filler (Vitoss BA, Orthovita). Materials and Methods A single level posterolateral fusion was performed in 72 adult rabbits at 6, 12 and 26 weeks (8 per group per time point). Group 1: nanOss Bioactive 3D + bone marrow aspirate (BMA) + autograft, Group 2: Vitoss BA + BMA and Group 3: Autograft + BMA were compared were compared using radiographic (X-ray and Micro-computed tomography (μCT), biomechanics (manual palpation and tensile testing at 12 and 26 weeks) and histology. Results Radiographic grading and μCT demonstrated progressive increases in radiopacity at the transverse processes and at the middle of the developing fusion for Groups 1 and 3. New bone formation was noted for Group 2 only at the transverse processes (not in the middle of the fusion site). In this challenging model, manual palpation revealed comparable fusion rates in Groups 1 and 3 (43% and 38%, respectively). None of the animals from Group 2 were fused by manual palpation. Group 3 outperformed Group 2 (P Discussion Posterolateral fusion models represent an extremely challenging biological site to evaluate bone graft materials and provide insight into clinical performance. Group 1 (nanOss Bioactive 3D + Autograft + BMA) performed well in the current model providing an osteoconductive scaffold that supported new bone formation on the transverse processes as well as in the middle of the fusion mass and that remodeled with time based on all endpoints. The graft materials had yet to completely resorb by 26 weeks in the current model. Group 2 performed well on the transverse processes in terms of new bone formation however new bone in the middle of the fusion mass was negligible at 6, 12, and 26 weeks. Group 3 (Autograft + BMA) performed well with new bone formation and remodeling on the transverse process and in the middle of the fusion mass as well as is consistently reported with this model.