Occluding dentin tubules with monetite paste / 华西口腔医学杂志

OBJECTIVES@#This study was performed to evaluate the occlusion of monetite paste on dentine tubule and provide a new potential method for treating dentine hypersensitivity.@*METHODS@#Calcium oxide, strontium chloride, and polyethylene glycol phosphate were mixed in a certain proportion and ground in a planetary ball mill. The reaction was carried out by adjusting the pH to obtain monetite and hydroxyapatite paste. The morphological characteristics of the paste were observed through scanning electron microscope (SEM). The structure and composition were analyzed through X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FTIR). The extracted third molar was selected to undergo demineralization to establish the @*RESULTS@#XRD and FTIR showed that the composition of the paste was mainly monetite, and the composition of hydroxyapatite paste was mainly composed of hydroxyapatite. SEM revealed that the size of the crystal particles of the synthesized paste was tens to hundreds of nanometers. Monetite and hydroxyapatite paste could produce a thicker mineralization layer on the dentin surface, and the mineralization of the dentin tubules of monetite was deeper than that of hydroxyapatite paste. The microhardness of the monetite paste group was significantly less than those of the hydroxyapatite paste groups (@*CONCLUSIONS@#Monetite paste could effectively block the exposed dentin tubules and be used for treating dentin hypersensitivity.

A study on the effect of biomineralization and phosphorylation performed on the titanium implant surfaces / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To suggest a chemical surface treatment for titanium and to initiate the formation of hydroxycarbonated apatite (HCA) on titanium surface during in vitro bioactivity tests in simulated body fluid (SBF).</p><p><b>METHODS</b>To improve the bone-bonding ability of Ti implants, commercially pure titanium (cpTi) by a simple chemical pre-treatment in orthophosphoric acid (H(3)PO(4)) with different density was activated, and then the phosphorylation specimens were soaked in SBF to investigate the function of biomineralization.</p><p><b>RESULTS</b>The scanning electron microscope (SEM) photographs showed that the surfaces of the pre-treated samples were characterized by a complex construction, which consisted of a mesh-like morphology matrix (a micro-roughened surface) and an uniform surface with different morphous of titanium dihydrogen orthophosphate [Ti(H(2)PO(4))(3)] crystal. After 14 days in SBF a homogeneous biomimetic apatite layer precipitated.</p><p><b>CONCLUSIONS</b>These data suggest that the treatment of titanium by acid etching in orthophosphoric acid is a suitable method to provide the titanium implant with bone-bonding ability.</p>

Preparation and cytocompatibility of apatite-porous fibers composite / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this article was to prepare apatite-porous fibers composite through biominetic synthesis and to investigate its cytocompatibility.</p><p><b>METHODS</b>Phosphate groups were incorporated into the surface of natural porous fiber-corncob by chemical modification. After precalcification, corncob was immersed into simulated body fluid. The surface of composite was observed through scanning electron microscope (SEM) and X-ray diffraction. Infant rat calvarias osteoblasts were isolated and expanded in vitro and the cells were seeded onto composite. Osteoblasts growth, proliferation and differentiation were assessed through SEM, MTT and alkaline phosphatase (ALP).</p><p><b>RESULTS</b>Apatite crystal was formed on the surface of corncob after reaction. Cell adhered and spread well on the surface of the composite, having high abilities of proliferation and synthesis of ALP.</p><p><b>CONCLUSION</b>There is good compatibility between the osteoblast and apatite-porous fibers composite. This composite may serve as a potential biomaterial used in bone repair and regeneration.</p>