An analytical expression of Coulomb interaction between a sphere and a cylindrical rod was derived. Along with a recently reported van der Waals interaction expression, the derived Coulomb interaction expression, for the first time, allows one to quantitatively evaluate the activation energy in the oriented attachment growth of colloidal nanorods.

This study describes 146 primary total knee replacements, either fully or partially coated with hydroxyapatite of which 74 knees in 68 patients were available for clinical and radiological assessment at a mean of 11.2 years (10 to 15). The global failure rate was 1.37% and survival rate with mechanical failure as the end-point was 98.14%. Radiological assessment indicated intimate contact betwe...

The bonding strength between bone and alpha-2-cyanoacrylate polymers, with or without the addition of powdered hydroxyapatite, was determined. The tensile strength of a bone-cyanoacrylate bond was measured for each polymer: 4.31 +/- 0.88 MPa (methyl-), 5.74 +/- 0.62 MPa (ethyl-), and 8.33 +/- 0.41 MPa (isobutyl-). The tensile strength of the isobutyl-2-cyanoacrylate bond increased to 12.03 +/- ...

Atomic force microscopy, infrared spectroscopy and NMR studied morphological and physicochemical properties of calcium hydroxyapatite powders produced by changing the temperature parameters of synthesis. Features of morphology formation of calcium hydroxyapatite nanoparticles with an annealing temperature within 200°C to 1,100°C were determined. It is shown that the particle size of the apatite...

OBJECTIVE To determine the incidence of complications and the outcome associated with the use of three kinds of ocular porous implants. MATERIAL AND METHOD Retrospective review of 133 consecutive case series. All patients undergoing orbital implantation either primary or secondary implantation of 49 coral hydroxyapatite, 43 human bone hydroxyapatite and 39 bovine bone hydroxyapatite from Sept...

Silver doped hydroxyapatite was prepared by the precipitation method, using the precursor of hydroxyapatite, CaCl2-0.5M and (NH4) 2HPO4-0.3M; silver sulfate (Ag2SO4) is added to the precursors in order to bring the ions of silver (Ag at 10%) in the structure of hydroxyapatite. The morphology, structure and composition of prepared samples were characterized by X-ray diffraction, the complex ther...

This study evaluates the cytotoxic and mutagenic effect of synthetic hydroxyapatite granules (source: School of Material and Mineral Resources Engineering, Universiti Sains Malaysia) in the bone marrow cells of mice. Mice are exposed to synthetic hydroxyapatite granules, the bone marrow cells are collected and observed for chromosome aberrations. No chromosome aberrations were noticed in the an...

Dietary components rich in polyphenols-for example, tea and red wine-are thought to cause tooth staining. In the present study, hydroxyapatite was used as a model of enamel for study of the influence of salivary proteins on the binding of different polyphenols to hydroxyapatite in vitro. Neither salivary protein pellicles nor salivary proteins in solution significantly altered the binding of th...

Fundamental to the processes of decalcification of or adhesion to mineralized tissues is the molecular interaction of acids with hydroxyapatite. This study was undertaken to chemically analyze the interaction of 1 mono-, 2 di-, 1 tri-, and 2 polycarboxylic acids with hydroxyapatite in an attempt to elucidate the underlying mechanism. Maleic, citric, and lactic acid decalcified hydroxyapatite, i...

PURPOSE To evaluate and compare clinically and radiographically use of hydroxyapatite crystals and 2% glutaraldehyde as a pulpotomy agent. METHOD Thirty deciduous molars were treated with pulpotomy using hydroxyapatite crystals and 2% glutaraldehyde. RESULTS Clinical and radiographic findings were observed at three months and six months. The success rate was found to be 100% clinically and ...