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 carrier used as delivery agent for bone morphogenetic proteins(BMPs) should also act as a scaffold for new bone formation. Moreover, bone formation should be predictable in terms of the volume and shape. This study examined the osteogenic effect of macroporous biphasic calcium phosphate (MBCP) block combined with ePTFE membrane as a carrier for recombinant human bone morphogenetic proteins (rhBMP-2). In addition, the additive effect of ePTFE membrane on bone formation was evaluated. MATERIALS AND METHODS: Eight-millimeter critical sized calvarial defects were created surgically in 28 male Sprague-Dawley rats. The animals were divided into 2 groups containing 14 animals each. The defects were treated with either rhBMP-2/MBCP block (rhBMP-2/MBCP group) or rhBMP-2/MBCP block/ePTFE membrane (rhBMP-2/MBCP/ePTFE group). A disc-shaped MBCP block (3 mm height and 8 mm diameter) was used as the carrier for the rhBMP-2 and ePTFE membrane was used to cover the rhBMP-2/MBCP block. The histologic and histometric parameters were used to evaluate the defects after 2- or 8-week healing period (7 animals/group/healing interval). RESULTS: The level of bone formation in the defects of both groups was significantly higher at 8 weeks than that at 2 weeks (P < 0.05). The ePTFE membrane has no additional effect compared with the rhBMP-2/MBCP block only. However, at 8 weeks, rhBMP-2/MBCP/ePTFE group showed more even bone formation on the top of the MBCP block than the rhBMP-2/MBCP group. CONCLUSION: These results suggest that the ePTFE membrane has no additive effect on bone formation when a MBCP block is used as a carrier for rhBMP-2.
Animals ; Bone Morphogenetic Proteins ; Calcium ; Durapatite ; Humans ; Hydroxyapatites ; Male ; Membranes ; Osteogenesis ; Rats ; Rats, Sprague-Dawley

STUDY DESIGN: Prospective randomized noninferiority trial. PURPOSE: To evaluate whether the union rate of anterior cervical discectomy and fusion (ACDF) using a polyetheretherketone (PEEK) cage filled with a mixture of hydroxyapatite (HA) and demineralized bone matrix (DBM) is inferior to that of a mixture of beta-tricalcium phosphate (beta-TCP) and HA. OVERVIEW OF LITERATURE: There have been no clinical trials investigating the outcomes of a mixture of HA and DBM in a PEEK cage in ACDF. METHODS: Eighty-five eligible patients were randomly assigned to group B (n=43), in which a PEEK cage with a mixture of HA and DBM was used, or group C (n=42), in which a PEEK cage with a mixture of HA and beta-TCP was used. The primary study endpoint was the fusion rate, which was assessed with dynamic radiographs and computed tomography (CT) scans. Secondary endpoints included pain intensity using a visual analogue scale, functional outcome using a neck disability index score, laboratory tests of inflammatory profiles, and the infection rate. RESULTS: Seventy-seven patients (38 in group B and 39 in group C) were included in the final analysis. One year postoperatively, bone fusion was achieved in 87% of group B patients and 87% of group C patients on dynamic radiographs, and 87% of group B patients and 72% of group C patients on CT scans (p=1.00 and 0.16, respectively). There were also no between-groups differences with respect to the secondary endpoints. CONCLUSIONS: A HA/DBM mixture inside a PEEK cage can provide noninferior outcomes compared to a HA/TCP mixture in ACDF.
Bone Matrix* ; Diskectomy* ; Durapatite ; Humans ; Hydroxyapatites ; Neck ; Prospective Studies* ; Tomography, X-Ray Computed

PURPOSE: The preferred material for bone augmentation beyond the envelope of skeletal bone is the bone block graft, due to its dimensional stability. We evaluated the necessity of rigid fixation for the bone block graft, and compared the bone regeneration and volume maintenance associated with grafting using a synthetic hydroxyapatite block (HAB) and an autogenous bone block (ABB) without rigid fixation on rabbit calvaria over two different periods. METHODS: Cylinder-shaped synthetic HAB and ABB were positioned without fixation on the rabbit calvarium (n=16). The animals were sacrificed at 4 or 8 weeks postoperatively, and the grafted materials were analyzed at each healing period using microcomputed tomography and histologic evaluation. RESULTS: Integration of the graft and the recipient bed was observed in all specimens, although minor dislocation of the graft materials from the original position was evident in some specimens (six ABB and ten HAB samples). A tendency toward progressive bone resorption was observed in the grafted ABB but not in the grafted HAB, which maintained an intact appearance. In the HAB group, the area of new bone increased between 4 and 8 weeks postoperatively, but the difference was not statistically significant. CONCLUSIONS: The nonfixed HAB was successfully integrated into the recipient bed after both healing periods in the rabbit calvaria. In spite of limited bone formation activity in comparison to ABB, HAB may be a favorable substitute osteoconductive bone material.
Animal Experimentation ; Animals ; Bone Regeneration ; Bone Resorption ; Dislocations ; Durapatite* ; Hydroxyapatites ; Osteogenesis ; Skull* ; Transplants* ; X-Ray Microtomography

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

BACKGROUND AND OBJECTIVES: Mastoid obliteration is the technique developed to reduce cavity problems after canal wall down mastoidectomy. Different materials have been explored for the technique, and of the variety of materials that have been used for mastoid obliteration, hydroxyapatite has gained particular attention. Hydroxyapatite can be made into a specific particle size, which affects the postoperative result. The aim of this study is to evaluate the histopathologic findings of mastoids obliterated with various particle sizes of hydroxyapatite in the temporal bullae of rat. Materials and Method: Rat bullaes were obliterated with hydroxyapatite and diversified into different particle sizes. In group 1, the mastoids were obliterated with Mimix(R) powder and in groups 2, 3, 4 with Bongros(R). The particle sizes were 0.3-0.6 mm, 0.6-1.0 mm and 1.0-3.0 mm each. After 3 months, the mastoids were examined under the microscope. RESULTS: In group 1, a new bone was formed in a consecutive fashion from the mastoid wall toward the center of the mastoid; there was no inflammation, with the new bone formation constituting 15%. In group 2, 3, 4, the proportion of new bone formation was higher than in the group 1, and constituted 40%, 55% and 60%, respectively. Inflammation was more severe when the particle size became larger. CONCLUSION: New bone formation was faster if larger hydroxyapatite particles were used; however, inflammation also increased. The powder form of hydroxyapatite was slow in new bone formation, but there was little inflammation. We therefore think that the hydroxyapatite is a very safe material.
Animals ; Blister ; Durapatite ; Hydroxyapatites ; Inflammation ; Mastoid ; Osteogenesis ; Particle Size ; Rats ; Temporal Bone

hydroxyapatites (HA/SF), as bone graft material when put into the calvarial defect of rats.METHODS: Twenty Sprague Dawley rats were used for this study and round shaped defects were formed in the center of parietal bones (diameter: 8.0 mm). The defect was filled with (1) HA/SF (experimental group), or (2) left as a vacant space (control group). The animals were sacrificed at 4 or 8 weeks, postoperatively. The specimens were decalcified and stained with Masson's trichrome for histomorphometric analysis.RESULTS: The average of new bone formation was 33.18+/-3.10% in the experimental group and 20.49+/-5.79% in the control group at 4 weeks postoperatively. That was 42.52+/-7.74% in the experimental group and 25.50+/-7.31% in the control group at 8 weeks postoperatively. The difference between the groups was significantly higher at both 4 weeks and 8 weeks postoperatively (P<0.05).CONCLUSION: The rat calvarial defect was successfully repaired by HA/SF graft. The HA/SF graft showed more new bone formation compared with the unfilled control.]]>
Animals ; Bone Regeneration ; Durapatite ; Fibroins ; Hydroxyapatites ; Osteogenesis ; Parietal Bone ; Rats ; Rats, Sprague-Dawley ; Silk ; Transplants