The hydroxyapatites were popularly been used as the ocular implant due to low incidence of post-operative exposure, infections, and excellent motility. For this purpose, it has been known that the drilling and peg implantations are performed after ingrowth of fibrovascularization tissue into the hydroxyapatites, so that ball and socket movement were occur. The authors reviewed 140 patients(140 eyes) who received enucleation or evisceration with the implantation of hydroxypapatite from Dec. 1991 to Jun. 1995. We performed that drilling after confirmation of the fiborvascularized hydroxyapatite by Technetium-99m-MDP bone scan, and investigated the method and complications. Among the 140 eyes(140 Patients), 39 eyes(28%) were found to have complications: 17 cases of peg extraction(44%), 10 cases of peg protrusion(26%), 4 cases of over-growth of granulation tissue(11%), 3 cases of poor motility(7%), 3 cases of hydroxyapatite exposure(7%) and 2 cases of malposition of peg(5%). Redrilling was performed in 20 eyes(51%) and exchanged by the screw peg due to re-extraction of peg in 4 eyes(20%). In a conclusion, overall the frequency of complications after drilling was about 28% and the most frequent complication was peg extraction.
Durapatite* ; Humans ; Hydroxyapatites ; Incidence

The change of conditions of hydroxyapatite synthesis can affect not oniy the material properties, but also the body reaction to the hydroxyapatite implants. To find out conditions for preparing more biocompatible hydroxyapatite implants as bone graft substitute. we evaluated the biologic response to the dense synthetic hydroxyapatite implants, made with various synthetic conditions, placed in corticocancellous defects of rabbits' long bone. The hydroxyapatites were synthesized with coprecipitation technique using Ca(NO3) 4H2O and (NH4)2HPO4, made with various Ca/P ratio and aging temperatures. Four kinds of hydroxyapatites were selected to use as implants(HA I: Ca/P ratio 1.5, aging temperature 90degrees C; HA V :1.5 , 30degrees C; HA VI: 1.83, 30degrees C; and HA lX: 1.67, 30degrees C). These hydroxyapatites were pressed and sintered at l300degrees C to fabricate dense plates. Biomechanical test and rnorphological examination were performed using Instron, light microscope and electron microscope. The characteristics of hydroxyapatite powder and sintered body were more significantly affected by siarting Ca/P ratios. The bonding strength of HA IX(1.67, 30degrees C) with bone was grcatest at 4 or 8 weeks after implantation with statistically significant difference(p<0.05). Bonding behavior betweeb HA IX and bone was most excellent in terms of new bone formation and new bone ingrowth into resorbed surface of hydroxyapatite plate.
Aging ; Durapatite* ; Hydroxyapatites ; Osteogenesis ; Transplants

STUDY DESIGN: Retrospective study. PURPOSE: To compare the union rate of posterolateral lumbar fusion (PLF) using demineralized bone matrix (DBM) versus hydroxyapatite (HA) as bone graft extender. OVERVIEW OF LITERATURE: To our knowledge, there has been no clinical trial to compare the outcomes of DBM versus HA as a graft material for PLF. METHODS: We analyzed prospectively collected data from consecutive 79 patients who underwent instrumented PLF. Patients who received DBM were assigned to group B (n=38), and patients who received HA were assigned into group C (n=41). The primary study outcome was fusion rate assessed with radiographs. The secondary outcomes included pain intensity using a visual analogue scale, functional outcome using Oswestry disability index score, laboratory tests of inflammatory profiles and infection rate. RESULTS: One year postoperatively, bone fusion was achieved in 73% in group B and 58% in group C without significant difference between the groups (p=0.15). There were no differences between the groups with respect to secondary outcomes. CONCLUSIONS: DBM would provide noninferior outcomes compared to the HA as a fusion material for PLF, and could be a notable alternative.
Bone Matrix* ; Durapatite* ; Humans ; Hydroxyapatites ; Prospective Studies ; Retrospective Studies ; Transplants

PURPOSE: The purpose of this study was to histomorphometrically evaluate the osteoconductivity of a new biphasic calcium phosphate ceramics with fully interconnected microporous structure. MATERIAL AND METHODS: Osseous defects created in the rabbit calvaria were filled with four different bone graft substitutes. Experimental sites were filled with a new fully interconnected microporous biphasic calcium phosphate with(BCP-2) or without(BCP-1) internal macropore of 400micrometer in diameter. MBCP(Biomatlante, France) and Bio-Oss(Geistlich Pharma, Switzerland) were used as controls in this study. Histomorphometric evaluation was performed at 4 and 8 weeks after surgery. RESULT: In histologic evaluation, new bone formation and direct bony contact with the graft particles were observed in all four groups. At 4 weeks, BCP-1(15.5%) and BCP-2(15.5%) groups showed greater amount of newly formed mineralized bone area(NB%) compared to BO(11.4%) and MBCP(10.3%) groups. The amounts of NB% at 8 weeks were greater than those of 4 weeks in all four groups, but there was no statistically significant differences in NB% between the groups. CONCLUSION: These results indicate that new bone substitutes, BCP with interconnected microporous structure and with or without internal macroporous structures, have the osteoconductivity comparable to those of commercially available bone substitutes, MBCP and Bio-Oss.
Bone Substitutes ; Calcium ; Ceramics ; Hydroxyapatites ; Minerals ; Osteogenesis ; Skull ; Transplants

PURPOSE: The aim of this study was to evaluate the improvement of osteogenic potential of biphasic calcium phosphate (BCP) bone substitute coated with synthetic cell-binding peptide sequences in a standardized rabbit sinus model. METHODS: Standardized 6-mm diameter defects were created bilaterally on the maxillary sinus of ten male New Zealand white rabbits, receiving BCP bone substitute coated with synthetic cell binding peptide sequences on one side (experimental group) and BCP bone substitute without coating (control group) on the other side. Histologic and histomorphometric analysis of bone formation was carried out after a healing period of 4 or 8 weeks. RESULTS: Histological analysis revealed signs of new bone formation in both experimental groups (4- and 8-week healing groups) with a statistically significant increase in bone formation in the 4-week healing group compared to the control group. However, no statistically significant difference in bone formation was found between the 8-week healing group and the control group. CONCLUSIONS: This study found that BCP bone substitute coated with synthetic cell-binding peptide sequences enhanced osteoinductive potential in a standardized rabbit sinus model and its effectiveness was greater in the 4-week healing group than in the 8-week healing group.
Artificial Cells ; Bone Regeneration ; Bone Substitutes ; Calcium ; Durapatite ; Humans ; Hydroxyapatites ; Male ; Maxillary Sinus ; Oligopeptides ; Osteogenesis ; Rabbits

PURPOSE: The purpose of this study is to develop hydroxyapatite cement simplified procedures for reconstruction of craniofacial deformities. Due to its expense and characteristics of quick hardening time, it may be inappropriate for forehead reconstruction or augmentation. Therefore we hear by introduce a more precise, easy and cheap method. The authors report forehead reconstruction with hydroxyapatite cement for a patient who suffered from craniofacial deformity. METHODS: Case report and literature review. RESULTS: A 35 year old man came to us with forehead and temporal area depression. He had a history of brain operations due to traumatic epidural hematoma. A physical exam showed an evidence of right side forehead weakness sign. Authors made RP model of his skull and applied check framework with Kirschner's wires for measuring accurate volume and contour on the depressed right side forehead area on the RP model. After complete exposure of defect area by bicoronary insicion, absorbable plate which applied on skull area was removed. Using three Kirschner's wires, authors made check framework on the right forehead lively and fixed with 2-hole miniplates on the boundary of the defect. After checking asymmetry, hydroxyapatite was applied on check shape framework just above Kirschner's wire. After removing Kirschner's wire, we corrected minimal unbalance and contour with bur. CONCLUSION: Check framework with Kirschner's wire was very convenient and cost saving methods for forehead reconstruction with hydroxyapatite cement.
Brain ; Congenital Abnormalities ; Cost Savings ; Depression ; Durapatite ; Forehead ; Hematoma ; Humans ; Hydroxyapatites ; Porphyrins ; Skull

OBJECTIVETo prepare and observe the physicochemical properties of scaffold materials of heterogeneous deproteinized tissue-engineered bone.

METHODSDeproteinized bone was made through a series of physicochemical treatments in pig ribs and analyzed with histological observation, scanning electron microscopy, infrared spectrum, X-ray diffraction and energy dispersive analysis, Kjeldahl determination and mechanics analysis.

RESULTSInterstitial collagen fiber was positive and mucin was negative in deproteinized bone, but, both were positive in fresh bone. Deproteinized bone maintained natural pore network. Its pore size was 472.51 micromolar+/-7.02 micromolar and the porosity was 78.15%+/-6.45%. The results of infrared spectrum showed that collagen was present in deproteinized bone. Both fresh and deproteinized bone had curve of hydroxyapatite. The Ca/P ratios were 1.71+/-0.95 and 1.68+/-0.76 (P larger than 0.05), and the protein contents were 26.6%+/-2.23% and 19.1%+/-2.14% (P less than 0.05) in fresh and deproteinized bone, respectively. There was no significant difference of destruction load under compression and maximal destruction load between fresh and deproteinized bone (P larger than 0.05). The elastic modulus was higher in deproteinized bone than that in fresh bone (P less than 0.05).

CONCLUSIONSPhysicochemical properties and mechanic strength of deproteinized tissue-engineered bone meet the demands of ideal scaffold materials. But, its immunogenicity should be observed through further experiments for its clinical applications.

Animals ; Biomechanical Phenomena ; Bone and Bones ; chemistry ; physiology ; Hydroxyapatites ; Materials Testing ; Swine ; Tissue Engineering

OBJECTIVETo explore suitable scaffold material for big segmental long bone defect by studying the properties of the prepared deproteinized bone.

METHODSCancellated bone were made as 30 mm x mm x 3 mm bone blocks from inferior extremity of pig femur along bone trabecula. The deproteinized bone was prepared with an improved method. Their morphological features, components, cell compatibility, mechanical and immunological properties were investigated respectively.

RESULTSDeproteinized bone maintained natural reticular pore system. The main organic material is collagen I and inorganic composition is hydroxyapatite. It has good mechanical properties, cell adhesion rate and histocompatibility.

CONCLUSIONThis deproteinized bone can be applicable as scaffold for reparation of big segmental defect in long bone.

Animals ; Bone Regeneration ; physiology ; Bone Transplantation ; methods ; Collagen ; Hydroxyapatites ; Swine ; Tissue Engineering ; methods ; Tissue Scaffolds

Cytotoxicity and cytocompatibility remains the principal theme for biomaterials application in medicine. The purpose of this study was to investigate the cytotoxicity and cytocompatibility of collagen/hydroxyapatite(CHA) composite material in vitro in order to provide useful scientific basis for clinical use. Cellular cultivation in vitro and MTT assay were conducted for evaluating the composite material's influence on the morphology, growth and proliferation of cultured cell(L-929 cell). The hemolysis test was also performed for evaluating the impact on the function and metabolism of erythrocyte. These results demonstrated that the CHA composite material had no cytotoxicity and no hemolytic effect, and it might not be harmful to the morphology of the L-929 cell. The growth and proliferation of the L-929 cell could not be inhibited significantly. The cytotoxicity score of the composite material was grade 0. The hemolysis rate was 1.85%. In conclusion, collagen/hydroxyapatite (CHA) composite material might have good cytocompatibility and be safe for clinical use.
Animals ; Biocompatible Materials ; toxicity ; Cells, Cultured ; Collagen ; toxicity ; Hydroxyapatites ; toxicity ; Mice ; Prostheses and Implants ; Toxicity Tests ; Trachea

OBJECTIVETo observe the experimental results and histopathological changes of acellular xenogenic dermal matrix (X-ADM) and allogeneic sclera used as wrapping materials of hydroxy apatite (HA) ocular implants in New Zealand white rabbits.

METHODSTwenty-four rabbits received unilateral eye enucleating and the sockets were implanted with HA spherical implants wrapped with either acellular xenogenic dermal matrix or allogeneic sclera at random. The rabbits were examined for inflammation and implant exposure and sacrificed at 1, 2, 4, 6, 8 and 12 weeks after implantation. The sockets with the grafts were exenterated and the specimens were assessed histopathologically and ultrastructurally with light or transmission electron microscopy for the changes in inflammation reaction and vascularization.

RESULTSCompared to allogeneic sclera at the same stage of implantation, acellular xenogenic dermal matrix demonstrated more active and earlier growth of fibroblasts and new vessels with abundant collagen deposition. There were few inflammatory cells and no rejection was found.

CONCLUSIONThis experiment showed that the acellular xenogenic dermal matrix, with fast neovascularization and low immunity, can be an ideal material of ocular implant and a good substitute for allogeneic sclera.

Animals ; Dermis ; transplantation ; Eye, Artificial ; Female ; Hydroxyapatites ; Male ; Rabbits ; Sclera ; transplantation ; Swine ; Transplantation, Heterologous ; Transplantation, Homologous