Ben Cang Cui,Jing Li,Hui Ning Wang,Yuan Hua Lin,Yang Shen,Ming Li,Ce Wen Nan
Polymer-infiltrated-feldspar used for restorative composite CAD/CAM blocks were prepared by infiltrating polymerizable monomers into the partially sintered feldspar blocks. The flexural strength was tested according to the standard of ISO-4049. The micro-structure was examined by SEM. The effects of sintering temperature, high pressure and the addition of SiO2 and Al2O3 on the ultimate flexural strength were evaluated. The flexural strength corresponding to infiltration with pressure was much higher than that without pressure at high sintering temperature. The addition of SiO2 and Al2O3 into the natural feldspar mineral increased the flexural strength of the blocks significantly.
Bencang Cui,Jing Li,Huining Wang,Yuanhua Lin,Yang Shen,Ming Li,Xuliang Deng,Cewen Nan
Objective To fabricate indirect restorative composites for CAD/CAM applications and evaluate the mechanical properties. Methods Polymer-infiltrated-ceramic composites were prepared through infiltrating polymer into partially sintered sodium aluminum silicate ceramic blocks and curing. The corresponding samples were fabricated according to standard ISO-4049 using for mechanical properties measurement. The flexural strength and fracture toughness were measured using a mechanical property testing machine. The Vickers hardness and elastic modulus were calculated from the results of nano-indentation. The microstructures were investigated using secondary electron detector. The density of the porous ceramic blocks was obtained through TG-DTA. The conversion degrees were calculated from the results of mid-infrared spectroscopy. Results The obtained polymer infiltrated composites have a maximum flexural strength value of 214 ± 6.5 MPa, Vickers hardness of 1.76–2.30 GPa, elastic modulus of 22.63–27.31 GPa, fracture toughness of 1.76–2.35 MPa m 1/2 and brittleness index of 0.75–1.32 μm −1/2 . These results were compared with those of commercial CAD/CAM blocks. Our results suggest that these materials with good mechanical properties are comparable to two commercial CAD/CAM blocks. Conclusion The sintering temperature could dramatically influence the mechanical properties. Clinical significance Restorative composites with superior mechanical properties were produced. These materials mimic the properties of natural dentin and could be a promising candidate for CAD/CAM applications.
Wang Huining,Cui Bencang,Li Jing,Li Shu,Lin Yuanhua,Liu Deping,Li Ming
A new type of polymer-infiltrated-ceramic-network composites (PICNs) was fabricated by infiltrating methacrylate-based monomers into partially sintered porous ceramics. The mechanical properties (flexural strength, flexural modulus, elastic modulus, Vickers hardness, fracture toughness) were investigated and compared with that of the natural tooth and common commercial CAD/CAM blocks. Our results indicated that sintering temperature and corresponding density of porous ceramics have an obvious influence on the mechanical properties, and PICNs could highly mimic the natural tooth in mechanical properties. The biocompatibility experiments evaluated through in vitro cell attachment and proliferation of BMSCs showed good biocompatibility. The mechanical properties and biocompatibility confirmed that PICN could be a promising candidate for CAD/CAM blocks for dental restoration.
To investigate the influence of fabrication method on the biological properties of modified PEEK. Two materials were tested in this study: press and CAD/CAM milled ceramic-reinforced PEEK (BioHPP, Bredent, Germany). The residual diphenyl sulfone in these two materials was detected and their biological effects on human gingival fibroblasts (HGFs) were evaluated by assaying cell viability, apoptosis, and inflammation. Diphenyl sulfone was not detected in press and milled BioHPP. The cell viability of them complied with ISO standards. The mRNA expression levels of Bax and Caspase-3 were up-regulated and that of Bcl-2 was downregulated when HGFs were cultured with the eluates of these two materials. There was no difference in cell viability, apoptosis, and inflammation between them. Hence, the fabrication method did not affect the biological properties of modified PEEK, the press and CAD/CAM milled modified PEEK all presented favorable cytocompatibility despite the expression of apoptosis-associated genes at the mRNA level.
危险品化学品经营许可证（带存储）