Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Hydroxyapatites”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 541 records · Page 30Linked to original sources
PubMedDate not supplied

Complications of hydroxyapatite use for transnasal closure of cerebrospinal fluid leaks.

BACKGROUND: Hydroxyapatite cement (HAC) was first introduced in the 1980s as a new method for bone replacement. However, it has not been recommended for use in areas exposed to air. Despite this, surgeries have been performed using HAC to close nasal/sinus cerebrospinal fluid (CSF) leaks or in the treatment of encephaloceles. METHODS: This study retrospectively documented four patients in whom HAC was used for closure of ethmoid and sphenoid sinus CSF leaks. RESULTS: This study showed that exposed hydroxyapatite could be extremely problematic resulting in scarring, chronic granulation, infection, and prolonged healing. Oftentimes, revision surgery was necessary to help control the reaction to hydroxyapatite. CONCLUSION: Because of the frequent complications occurring with use of hydroxyapatite in the paranasal sinuses, its use should be limited to selected individuals in whom difficulty in achieving closure of the CFS leak could be anticipated and in whom adequate tissue coverage could be provided.

Aged↗
PubMed2003

[Preliminary report on primary drilling procedure at the time of hydroxyapatite orbital implant].

OBJECTIVE: To evaluate the clinical effect of the drilling and inserting a motility peg at the time of hydroxyapatite orbital implant. METHODS: After drilling and insertion of a titanium motility peg, a hydroxyapatite orbital implant was inserted in 31 consecutive patients. Of the 31 patients, 23 had been referred for primary enucleation and 8 for secondary implant surgery. The titanium-threaded sleeve was driven into the hydroxyapatite after which the titanium flat-headed peg was inserted into the sleeve before orbital implantation. The flat-headed peg was replaced with a titanium motility/support peg 3 to 7 months later. RESULTS: Follow-up ranged from 3.0 to 11.0 months (mean, 6.9 months). All patients were successfully fit with prostheses. Prosthetic motility was acceptable in each patient. 12 of 31 titanium flat-headed pegs became spontaneously and partially exposed within 3 to 7 months. There were no cases of secondary infection, implant exposure or extrusion of the motility peg. CONCLUSION: The hydroxyapatite orbital implant primary drilling procedure gives good cosmetic results with good motility of the artificial eye. It does not result in increased complications, and is an effective and efficient surgical option.

Adolescent↗
PubMed2003

Hydroxyapatite ceramics as a particulate embolic material: report of the clinical experience.

BACKGROUND AND PURPOSE: Our newly developed biocompatible embolic materials, hydroxyapatite ceramic microparticles, have good visibility during injection control and were shown to be capable of producing effective occlusion of the distal arteriocapillary bed in an experimental animal study. The purpose of this present study was to evaluate hydroxyapatite ceramic microparticles for use in human meningioma embolization. METHODS: Thirteen patients with meningiomas underwent preoperative superselective embolization with the use of hydroxyapatite microparticles. Radiologic and histopathologic studies of the surgical specimens were performed. RESULTS: During embolization, no microcatheter clogging was observed and angiographic devascularization was consistently obtained without unexpected proximal occlusions. Histopathologic findings showed that there was mild inflammatory response in the thrombosed lumen. CONCLUSION: Hydroxyapatite microparticles are excellent embolic materials for the treatment of human meningioma. They have excellent biocompatibility and good injection control, which produces occlusion of the distal arteriocapillary bed.

Adult↗
PubMed2001

[Experimental study on apical sealing ability of Sankin hydroxyapatite root canal sealer].

OBJECTIVE: To compare the apical sealing ability of Sankin hydroxyapatite root canal sealer with traditional root canal sealers. METHODS: Determination of the length of apical dye leakage by methylene leakage test. RESULTS: The length of apical dye leakge of Sankin hydroxyapatite root canal sealer was 2.40 mm, that of iodoform paste and zinc oxide eugenol paste was 4.37 mm and 5.80 mm,respectively. There was no significant difference between iodoform paste and zinc oxide-eugenol paste (P>0.05);whereas there was significant difference between Sankin hydroxyapatite root canal sealer and iodoform paste or zinc oxide eugenol paste(P<0.01). CONCLUSION: Sankin hydroxyapatite root canal sealer has better apical sealing ability than traditional root canal sealers.

English Abstract↗
PubMed2004

[Efficacy of double-door laminoplasty combined with hydroxyapatite artificial bone grafting for cervical spinal stenotic myelopathy].

OBJECTIVE: To evaluate the effects of double-door laminoplasty and hydroxyapatite artificial bone grafting in the treatment of cervical spinal stenotic myelopathy. METHODS: Twelve cases of cervical spinal stenotic myelopathy underwent expansive double-door laminoplasty of the cervical spine and hydroxyapatite artificial bone grafting. The clinical outcome of the patients and the operative procedures were assessed. RESULTS: The 5-year follow-up showed significantly alleviated clinical symptoms and improved physical signs in all the patients except for 1 patient who responded poorly to the surgery. CONCLUSIONS: Expansive double-door laminoplasty of the cervical spine in combination with hydroxyapatite artificial bone grafting is safe and effective for treating cervical spinal stenotic myelopathy. Hydroxyapatite artificial bone possesses good biological compatibility and osteoconduction, and is applicable in the laminoplasty procedures as an ideal bone graft material.

Aged↗
PubMed2004

[Semiconductor low level laser irradiation for exposure of hydroxyapatite orbital implants].

OBJECTIVE: To evaluate the efficacy of semiconductor low level laser irradiation for the treatment of postoperative exposure of hydroxyapatite orbital implants. METHODS: 22 cases with postoperative exposure of hydroxyapatite orbital implants were divided into three groups according to the size of implants exposure. The exposure wound in the 3 groups was irradated with semiconductor low level laser 5 min per day for 5-15 days. The follow-up period ranged from 2 to 24 months. RESULTS: In the group with less then 3 mm of exposure, the wound healed in 1 week after 5-10 days irradiation; in the group with implant exposure of 4-7 mm, the would healed in 1-2 weeks after 10-15 days irradiation; in the group with implant exposure of 8-10 mm, the would healed in 2-3 weeks after 10-15 days irradiation. Compared with the treatments of drugs and/or surgical repair, which was used for another 20 cases of exposure of hydroxyapatite orbital implants, semiconductor low level laser increased healing rate obviously in the groups with implant exposure of 4-7 mm and 8-10 mm (P = 0.019, 0.018). CONCLUSION: Semiconductor low level laser has better effects than drugs and/or surgical repair for exposure of hydroxyapatite orbital implants.

Adolescent↗
PubMed2005

[Toxicity of hydroxyapatite nanoparticles on rabbits].

OBJECTIVE: To study the toxicity of nano-hydroxyapatite on rabbits by vein. METHODS: The hydroxyapatite solution was intravenous injected into 50 New Zealand white rabbits with different concentration, then to observe the reactions and the survial rates of rabbits, and to investigate the effects of nano-HA to the liver function, renal function, enzyme and Ca, Mg, P. RESULTS: The medium lethal dosege of nano-HA administrated intravenous (iv) was determined as 200mg/kg. The level of phosphorous increased but calcium and magnesium kept stable. LDH, CPK, GOP and GDT dramatically increased in 30 minutes after injection, arriving the peak at 2 hours later, however, they all returned to normal 24h after injection. BUN and ALP got to the peak at 24 hours later, then decreased rapidly to normal level. The other indexes almost maintained at normal level. CONCLUSION: Nano-hydroxyapatite has no accumulative toxicity to rabbits, it is suggested that it is safe when the hydroxyapatite-sol was applied intravenously as a drug carrier in small dosage more less than the medium lethal dose, even as a kind of anticancer drug.

Animals↗
PubMedDate not supplied

[Late changes in a recipient's tissues after implantation of synthetic hydroxyapatite of varying density: an experimental morphological study].

The synthetic hydroxyapatite made in Russia was applied as an insert-implant to 4 rabbits (6 eyes, 6 eviscerations). These included 2 implants having a porosity of 40% and a pore size of 0.03-1.5 microm and 2 with a porosity of 63% and a pore size of 0.05-3.0 microm. The hydroxyapatite that is made in Russian and that has preferably a porosity of 40% and a pore size of 0.03-1.5 microm can be successfully used to make a locomotor stump after removal of the eyeball. The hydroxyapatite having these parameters more rapidly intergrows around the periphery with fibrovascular tissue and its vascular components mainly reduce by month 8. Our data suggest that the synthetic hydroxyapatite made in Russia may be used in ophthalmological care.

Animals↗
PubMed2006

[Culture of chondrocytes using collagen-hydroxyapatite composite scaffolds in vitro].

OBJECTIVE: To evaluate the feasibility and the value of the layered cylindric collagen-hydroxyapatite composite as a scaffold for the cartilage tissue engineering after an observation of how it absorbs the chondrocytes and affects the cell behaviors. METHODS: The chondrocytes were isolated and multiplied in vitro, and then the chondrocytes were seeded onto the porous collagen/hydroxyapatite composite scaffold and were cultured in a three-dimensional environment for 3 weeks. The effects of the composite scaffold on the cell adhesivity, proliferation, morphological changes, and synthesis of the extracellular matrix were observed by the phase-contrast microscopy, histology, scanning electron microscopy, and immunohistochemistry. RESULTS: The pore diameter of the upper layer of the collagen-hydroxyapatite composite scaffold was about 147 microm, and the porosity was 89%; the pore diameter of the bottom layer was about 85 microm and the porosity was 85%. The layered cylindric collagen-hydroxyapatite composite scaffold had good hydrophilia. The chondrocytes that adhered to the surface of the scaffold, proliferated and migrated into the scaffold after 24 hours. The chondrocytes attached to the wall of the microholes of the scaffold maintained a rounded morphology and could secrete the extracellular matrix on the porous scaffold. CONCLUSION: The layered cylindric collagen-hydroxyapatite composite scaffold has a good cellular compatibility, and it is stronger in the mechanical property than the pure collagen. It will be an ideal scaffold for the cartilage tissue engineering.

Animals↗
PubMed2005

Comparison the cytotoxicity of hydroxyapatite measured by direct cell counting and MTT test in murine fibroblast NIH-3T3 cells.

The worldwide growing interest to biomaterials over the last years results from their irreplaceable role in medical clinic. Hydroxyapatite is used in bone reconstruction because of its similar chemical structure compared to the inorganic composition of human bone and it is basic building component of many newly prepared biomaterials. In this study, we evaluated cytotoxic/antiproliferative activity of hydroxyapatite extract using murine fibroblast cell line NIH-3T3 and two in vitro different cytotoxic assays: growth inhibition assay and MTT assay. Hydroxyapatite extract after 72 h of incubation manifested the significant in vitro cytotoxic/antiproliferative effect only at the highest concentration tested (100 %). The antiproliferative effect of hydroxyapatite extract at the other concentrations tested (75 %, 50 %, 25 %, 10 %, 5 % and 1 %) was directly proportional to the concentration and the time of influence. The inhibition of cell proliferation was 86.8 - 0 %. The sensitivity of cell growth inhibition assay (direct counting of viable cells) to the extract influence was higher than that of MTT test.

Animals↗
PubMed2006

[The expression and activity of alkaline phosphatase in human periodontal ligament cells with nanometer hydroxyapatite].

OBJECTIVE: To investigate the effect of nanometer hydroxyapatite on the proliferation and the osteogenetic differentiation of periodontal ligament cells (PDLC). METHODS: Nano-hydroxyapatite powders were fabricated with sol-gel method. The fourth passage periodontal ligament cells were cultured with nanometer hydroxyapatite powder (nano-HA), dense hydroxyapatite powder (dense-HA) and only medium as control respectively. On the 5th, 8th day of culture, the osteogenetic differentiation of human periodontal ligament cells was evaluated though alkaline phosphatase (ALP) activity, ALP immunohistochemical stain and ALP positive flow cytometry. RESULTS: There were significant differences among nano-HA group, dense-HA group and control group on the 5th and 8th day of culture. A majority of nano-HA group and dense-HA group cells sample showed positive ALP stain. But the ALP positive stain of nano-HA group cells sample was denser than that of dense-HA group. In FCM, the distribution of ALP positive cells cultured with nanoparticles were significantly more than that of other groups. CONCLUSIONS: The nano-HA, as a calcium phosphate biomaterial, has ability to promote the activity of osteogenetic differentiation for periodontal ligament cells compared with dense-HA.

Alkaline Phosphatase↗
PubMed1995

Hydroxyapatite-coated hip prostheses. Early results from an international study.

A hydroxyapatite-coated hip prosthesis designed to stimulate proximal femoral stress transfer was studied in 222 patients undergoing primary total hip arthroplasty with a minimum followup of 2 years. The femoral component was a roughened titanium alloy with a 50-mu coating of hydroxyapatite applied to the proximal third. A proximal press-fit technique was applied with distal femoral over-reaming as standard procedure. The hydroxyapatite-coated acetabulum was of hemispherical design. Analysis of the clinical results showed a mean Merle D'Aubigné score of 16.7 points at 6 months and 17.4 points at 2 years. Mild residual thigh pain of unknown origin was reported in 3.6% of patients at 2 years. Radiographic evaluation showed complete acetabular and proximal femoral osseointegration without any loosening. No radiolucency or reactive line formation was observed around the hydroxyapatite-coated areas of the prostheses. Femoral bone densification occurred at the coated-uncoated transition zone (54%); 4% to 6% of cases showed cortical hypertrophy at the uncoated area of the stem. Reactive lines were seen around the distal stem in 52% of patients after 2 years. The clinical outcome was excellent, and the radiographic data pointed mainly to proximal femoral stress transfer.

Adult↗
PubMed1996

[The fate of hydroxyapatite ceramic granulate when implanted in a secondary bone defect of the mandible].

A patient is described, who was examined 1 year after surgery for mandibular cyst diagnosed as radicular near the !5 tooth and for plasty of the secondary osseous cavity with hydroxyapatite granulate. X-Ray examination revealed a cystic cavity near the roots of teeth !234. Histologic examination of tissue fragments and the remainder of hydroxyapatite granulate, obtained by cystectomy, helped diagnose a primordial cyst. Intensive bone regeneration was observed at the site of hydroxyapatite granule accumulation and fusion of the new bone with the granules to form a solid osseogranular complex. The authors recommend hydroxyapatite ceramic granules for surgical treatment of minor and medium bone defects and for corrective bone plasty.

Adult↗
PubMed1997

Rhenium-188 labeled hydroxyapatite and rhenium-188 sulfur colloid. In vitro comparison of two agents for radiation synovectomy.

AIM: One therapeutic approach to rheumatoid arthritis and other inflammatory arthropathies besides surgical removal of inflamed synovium is radiation synovectomy using beta-emitting radionuclides to destroy the affected synovial tissue. Up to now the major problem associated with the use of labeled particles or colloids has been considerable leakage of radionuclides from the injected joint coupled with high radiation doses to liver and other non target organs. In this study we compared 188Re labeled hydroxyapatite particles and 188Re rhenium sulfur colloid for their potential use in radiation synovectomy. METHODS: To this end we varied the labeling conditions (concentrations, pH-value, heating procedural and analyzed the labeling yield, radiochemical purity, and in vitro stability of the resulting radiopharmaceutical. RESULTS: After optimizing labeling conditions we achieved a labeling yield of more than 80% for 188Re hydroxyapatite and more than 90% for the rhenium sulfur colloid. Both of the radiopharmaceuticals can be prepared under aseptic conditions using an autoclave for heating without loss of activity. In vitro stability studies using various challenge solutions (water, normal saline, diluted synovial fluid) showed that 188Re labeled hydroxyapatite particles lost about 80% of their activity within 5 d in synovial fluid. Rhenium sulfur colloid on the other hand proved to be very stable with a remaining activity of more than 93% after 5 d in diluted synovial fluid. CONCLUSION: These in vitro results suggest that 188Re labeled rhenium sulfur colloid expects to be more suitable for therapeutic use in radiation synovectomy than the labeled hydroxyapatite particles.

Arthritis, Rheumatoid↗
PubMed1998

Enhanced fixation with hydroxyapatite coated pins.

Three groups of seven patients had external fixation of middiaphyseal tibial fractures using uncoated pins, uncoated bicylindrical pins, and hydroxyapatite coated bicylindrical pins, respectively. All fractures were fixed with six pins, and all fractures united. Median pin insertion torque was 0.6, 1.2, and 1.3 Nm in the three groups, respectively. Median extraction torque was 0.1, 0.1, and 2.1 Nm, respectively. Both types of stainless steel pins showed a lower extraction torque than insertion torque in all cases, whereas the mean extraction torque in the hydroxyapatite coated pins was unchanged. Seven of the 14 patients receiving uncoated pins had pin tract infection, compared with none of the patients receiving hydroxyapatite coated pins. Hydroxyapatite coating of external fixation pins increases stability and thereby reduces the risk for pin tract infection and mechanical failure of fracture fixation.

Adolescent↗
PubMed1998

Results of cavity reconstruction with hydroxyapatite implants after 15 years.

OBJECTIVE: The results of the first cohort of 60 cavity reconstructions with hydroxyapatite with a minimum follow-up period of 15 years were studied. STUDY DESIGN: The study design was a retrospective study. PATIENTS: A total of 60 patients had a follow-up period of >15 years. In four patients, not all data were available. Therefore, 56 patients were included in the study. They had a combination of cavity problems and hearing loss. INTERVENTION: The ear canal was reconstructed with a canal wall prosthesis of porous hydroxyapatite. The ossicular chain was reconstructed with an incus or incus-stapes prosthesis of dense hydroxyapatite. RESULTS: After 15 years, 42 patients (75%) had an intact reconstructed ear canal. The main problem for failure was the recurrent purulent middle ear infection and not cholesteatoma. The histology of the retrieved canal wall showed a good remodeling in living bone tissue. After 15 years, 34 patients had a normal ear canal and an ossicular chain. Of these patients, 7.05% had an air-bone gap closure within 20 dB. CONCLUSIONS: Long-term results of cavity reconstruction with hydroxyapatite are possible. The main problem is recurrent mucosal disease of the new middle ear-mastoid cleft.

Biocompatible Materials↗
PubMed1998

Antibiotic-loaded porous hydroxyapatite blocks for the treatment of osteomyelitis and postoperative infection. A preliminary report.

Hydroxyapatite blocks (HAB) can be used to administer antibiotics or anticancer drugs because its porous structure allows the gradual administration of the pharmacologic agents. A novel drug delivery system using hydroxyapatite blocks was developed for osteomyelitis and postoperative infections occurring after joint replacement. To load the antibiotics, hydroxyapatite blocks were mixed with an antibiotic solution and centrifuged at 1500 rpm for 15 minutes or decompressed in vacuum container at 5 to 10 in. Hg for 20 minutes. Fifteen patients with osteomyelitis including one with tuberculosis and four with infections subsequent to joint replacement were treated with antibiotic-loaded hydroxyapatite blocks in combination with intravenous injection. Except in one case, all of the foci had completely healed at follow-up (range: 13 to 71 months; average: 39.7 months). These new methods are simple and can safely treat osteomyelitis in a one-stage operation.

Aged↗
PubMedDate not supplied

Evaluation of hydroxyapatite cement for frontal sinus obliteration after mucocele resection.

OBJECTIVES: To retrospectively evaluate our experience with frontal sinus obliteration using hydroxyapatite cement (BoneSource; Stryker Biotech Europe, Montreux, Switzerland) and compare it with fat obliteration over the approximate same period. Frontal sinus obliteration with hydroxyapatite cement represents a new technique for obliteration of the frontal sinus after mucocele resection. METHODS: Exploration of the frontal sinus was performed using bicoronal, osteoplastic flaps, with mucosal removal and duct obliteration with tissue glue and muscle or fascia. Flaps were elevated over the periorbita, and Silastic sheeting was used to protect the BoneSource material from exposure as it dried. The frontal table was replaced when appropriate. RESULTS: Sixteen patients underwent frontal sinus obliteration with fat (fat obliteration group), and 38 patients underwent obliteration with BoneSource (BoneSource group). Fat obliteration failed in 2 patients, who underwent subsequent BoneSource obliteration, and none of the patients in the BoneSource group has required removal of material because of recurrent complications. Frontobasal trauma (26 patients [68%] in the BoneSource group and 9 patients [56%] in the fat obliteration group) was the most common history of mucocele formation in both groups. Major complications in the BoneSource group included 1 patient with skin fistula, which was managed conservatively, and 1 patient with recurrent ethmoiditis, which was managed surgically. Both complications were not directly attributed to the use of BoneSource. Contour deficit of the frontal bone occurred in 1 patient in the fat obliteration group and in none in the BoneSource group. Two patients in the fat obliteration group had donor site complications (hematoma and infection). Thirteen patients in the BoneSource group had at least 1 prior attempt at mucocele drainage, and no statistical relation existed between recurrent surgery and preservation of the anterior table. CONCLUSION: Hydroxyapatite is a safe, effective material to obliterate frontal sinuses infected with mucoceles, with minimal morbidity and excellent postoperative contour.

Adipose Tissue↗