This paper reports a high-yield process to fabricate biomimetic hydroxyapatite nano-particles or nano-plates. Hydroxyapatite is obtained by simultaneous dripping of calcium chloride (CaCl2) and ammonium hydrogen phosphate (NH4)2HPO4 solutions into a reaction vessel. Reactions were carried out under various pH and temperature conditions. The morphology and phase composition of the precipitates w...

For many years, glass-polyalkenoate cements have been described as possessing the unique properties of self-adherence to human hard tissues, such as bones or teeth. However, direct experimental evidence to prove the existence of chemical bonding has not been advanced. X-ray Photoelectron Spectroscopy (XPS) was used to analyze the chemical interaction of a synthesized polyalkenoic acid with enam...

Hydroxyapatite nanocrystals in natural form are a major component of bone--a known piezoelectric material. Synthetic hydroxyapatite is widely used in bone grafts and prosthetic pyroelectric coatings as it binds strongly with natural bone. Nanocrystalline synthetic hydroxyapatite films have recently been found to exhibit strong piezoelectricity and pyroelectricity. While a spontaneous polarizati...

The morphogenesis of bone in a porous hydroxyapatite substratum was studied after intramuscular implantation in adult primates. Replicas of porous hydroxyapatite that had been obtained after hydrothermal conversion of the calcium carbonate exoskeleton of coral (genus Goniopora) were implanted intramuscularly in twenty-four adult male baboons (Papio ursinus). Serial sections from specimens that ...

BACKGROUND Plasma-spray deposition of hydroxyapatite on titanium (Ti) has proven to be a suboptimal solution to improve orthopedic-implant success rates, as demonstrated by the increasing number of orthopedic revision surgeries due to infection, implant loosening, and a myriad of other reasons. This could be in part due to the high heat involved during plasma-spray deposition, which significant...

Transmission electron microscopy and standard chemiluminescence assays were used to investigate the in vivo effect of dichloromethylene bisphosphonate (clodronate) on the phagocytosis of pure hydroxyapatite particles by rat peritoneal macrophages and the production of chemiluminescence by the peritoneal exudate cells. Hydroxyapatite (control) and a hydroxyapatite/clodronate suspension (28 mumol...

Because of the limited observations of published studies, the condition of hydroxyapatite after a long period of intraoral function remains a concern. This clinical report describes the histologic evaluation of a 9 year-old hydroxyapatite specimen retrieved from a human subject. The residual hydroxyapatite particles showed no sign of resorption, and tight contact with the surrounding bone was o...

introduction: salivary calcium and phosphate levels might have a relationship with dental caries severity. evaluation of different indexes such as alkaline phosphatase, which increases salivary phosphate levels, and hydroxyapatite ion activity, which reflects salivary calcium and phosphate levels, might help determine the risk of dental caries. the aim of the present study was to compare saliva...

Data are summarized on the synthesis of hydroxyapatite (HA) by wet-chemical processes, solidstate reactions, and hydrothermal treatment. The conditions for HA preparation via precipitation from solutions of calcium chloride, dibasic ammonium phosphate, and aqueous ammonia are discussed at length. Detailed analysis of the fabrication and properties of calcium-phosphate-based ceramics is presente...

BACKGROUND The objective of this pilot study was to evaluate the effect of local application of low-magnitude high-frequency vibration (LMHFV) on the bone healing of rabbit calvarial defects that were augmented with different grafting materials and membranes. METHODS Four calvarial defects were created in each of two New Zealand rabbits and filled with the following materials: biphasic calciu...