Papers by Author: X.G. Wang

Abstract: Animal implants experiments are obligatory when developing human artificial hard tissues, such as bio-ceramics. Optical microscope is often used to inspect implant slices but may destroy original status when slicing up. We tried 3D high resolution CT to nondestructively study biocompatibility and degradation of bio-ceramics implants. 3D CT provides 3D structure information. Typical pixel size of 3D high resolution CT is 50 microns. Generally, implants differs with tissues in density and structure, on basis of which we can identify details with CT slice. Experiments of bio-ceramic implanted into rabbit hip are also showed. Interaction could be identified at interface between implant and tissue.

Abstract: This study aimed to show that the polymerization contraction of dental light cured resin-based materials, when it was used as adhesives on hard substrate, produces voids at the material/substrate interface. Two liner/base systems, one glass-ionomer, one restorative composite resins and two compomers were cured using mirror-like glass slide as a compliance-free reference substrate. The adhesive surface was analyzed by atomic force microscopy, and the polymerization contraction of bulk material was tested by laser beam scanning method. Nanoperiodic structure of 3D images, section analysis and roughness characteristics (Ra and Rz)) indicated that polymerization contraction produced voids at the interface. In visible light-cured (VLC) materials, the interface porosity decreased when an irradiation pause was carried out during gelation.