MRI compatibility of several early transition metal based alloys and its influencing factors.

Magnetic resonance imaging (MRI) compatibility of three early transition metal (ETM) based alloys was assessed in vitro with agarose gel as a phantom, including Zr-20Nb, near-equiatomic (TiZrNbTa) Mo and Nb-60Ta-2Zr, together with pure tantalum and L605 Co-Cr alloy for comparison. The artifact extent in the MR image was quantitatively characterized according to the maximum area of 2D images and the total volume in reconstructed 3D images with a series of slices under acquisition by fast spin echo (FSE) sequence and gradient echo (GRE) sequence. It was indicated that the artifacts extent of L605 Co-Cr alloy with a higher magnetic susceptibility (χ ) was approximately 3-fold greater than that of the ETM-based alloys with χ in the range of 160-250 ppm.

MRI-compatible Nb-60Ta-2Zr alloy used for vascular stents: haemocompatibility and its correlation with protein adsorption.

Nb-60Ta-2Zr is a newly developed MRI-compatible alloy used for vascular stents. In this work, its haemocompatibility was investigated, including platelet adhesion (lactate dehydrogenase activity), platelet activation (P-selectin expression), coagulation and haemolysis. For comparison, parallel assessments for these factors were performed for the niobium, tantalum, 316L stainless steel (316L SS) and L605 Co-Cr alloy (L605).

The responses of endothelial cells to Zr₆ ₁Ti ₂Cu₂₅Al₁₂ metallic glass in vitro and in vivo.

The goal of this study was to evaluate the biocompatibility of newly developed Zr61Ti2Cu25Al12 metallic glass (denoted ZT1) and its parallel material, commercially pure titanium (CP-Ti), as dental implants. To this end, we evaluated their cytotoxicity in vitro using human umbilical vein endothelial cells (HUVECs) and in vivo by performing an oral mucosa irritation test in hamsters. Specifically, cytotoxicity was determined in HUVECs by evaluating their cell morphology using scanning electron microscopy (SEM) and their cell viability using CCK-8 assays.

Activation of the ERK1/2 signaling pathway during the osteogenic differentiation of mesenchymal stem cells cultured on substrates modified with various chemical groups.

The current study examined the influence of culture substrates modified with the functional groups -OH, -COOH, -NH2, and -CH3 using SAMs technology, in conjunction with TAAB control, on the osteogenic differentiation of rabbit BMSCs. The CCK-8 assay revealed that BMSCs exhibited substrate-dependent cell viability. The cells plated on -NH2- and -OH-modified substrates were well spread and homogeneous, but those on the -COOH- and -CH3-modified substrates showed more rounded phenotype.

Zr61Ti2Cu25Al12 metallic glass for potential use in dental implants: biocompatibility assessment by in vitro cellular responses.

In comparison with titanium and its alloys, Zr61Ti2Cu25Al12 (ZT1) bulk metallic glass (BMG) manifests a good combination of high strength, high fracture toughness and lower Young's modulus. To examine its biocompatibility required for potential use in dental implants, this BMG was used as a cell growth subtract for three types of cell lines, L929 fibroblasts, human umbilical vein endothelial cells (HUVEC), and osteoblast-like MG63 cells. For a comparison, these cell lines were in parallel cultured and grown also on commercially pure titanium (CP-Ti) and Ti6-Al4-V alloy (Ti64).

Improvement on the performance of bone regeneration of calcium sulfate hemihydrate by adding mineralized collagen.

Comparative investigations of bone regeneration performance for calcium sulfate hemihydrate (CaSO(4).(1/2)H(2)O; CSH) only and CSH with mineralized collagen are reported in this article. The mineralized collagen is the nanohydroxyapatite/collagen (nHAC).

[Single cell gel electrophoresis of a magnesium alloy coated with beta-tricalcium phosphate].

Objective: To evaluate the genotoxicity of a magnesium alloy coated with beta-tricalcium phosphate (beta-TCP).

Methods: Four groups were designed. In the first group, AZ31B magnesium alloy surface was coated with beta-TCP using chemical bath deposition, and in the second group magnesium alloy was tested.

[The identification of electronic surveying lines on 3-D digital models of dentition defects].

Objectives: To develop a mathematical algorithm and a software package for the process of electronically surveying a scanned point cloud cast. To provide a principal premise to the subsequent computer aided design and computer aided manufacture (CAD/CAM) of removable partial denture framework, and to provide a method to improve quality control in the dental laboratory.

Methods: Point cloud data of a partially edentulous cast, a mandibular Kennedy Class II Modification 2 arch, was captured using an optical scanning system with projective grating and high-resolution digital camera.

[Resistance to cyclic fatigue of pulpless teeth with flared root canals restored with three kinds of post-and-cores].

Purpose: To observe the resistance to cyclic fatigue of maxillary incisors with flared canals restored with three post-and-core materials.

Methods: Standard cylindrical samples with flared canals were made of 48 human maxillary central incisors and were assigned randomly to two groups (without ferrule and 2mm ferrule). Each main group was then divided into 3 sub-groups of 8 specimens and restored with cast metal post-core-crown,carbon fiber+resin composite post-core-crown ,and glass fiber+resin composite post-core-crown, respectively.

[A study on the influence of fluid shear stress on the expression of COX-2 in HPDLF].

Purpose: To utilize the fluid shear stress to simulate occlusion trauma in vitro. Different density of FN was given to HPDLF and the amount of COX-2 mRNA of HPDLF was measured at different time.

Methods: Young healthy permanent teeth which were extracted for orthodontic treatment were collected.

[The ultrastructure and activities of free radical scavenger in discolored gingiva adjacent to porcelain fused to metal crowns].

Purpose: This study was designed to study the discolored gingiva adjacent to porcelain fused to metal (PFM) crowns in terms of ultrastructure , SOD and GSH activities in 40 cases.

Methods: The discolored gingival ultrastructures were observed and metal X-ray energy level was analyzed;The activities of SOD and GSH were measured and compared with normal control by student's t test and one-way ANOVA with SPSS10.0 software package.

[Computer aided design and computer aided manufacture of sacrificial pattern of removable partial denture framework].

Objective: To introduce a method applied in computer aided design and computer aided manufacture (CAD-CAM) of removable partial denture framework for rehabilitating edentulous arch of Kennedy Class II and found a basis for this project.

Methods: Point cloud data of dental stone model was obtained by laser scanning. The following processes were made: drawing framework outline on the reconstructed triangle mesh model, picking up and processing its inner side data as the data of tissue surface, shelling it for 3-D model of framework, and transferring the data to rapid prototyping equipment for manufacture.

[Design of geometric models of the removable partial denture framework].

Purpose: The aim of this study was to introduce a method on computer aided design (CAD) of removable partial denture(RPD) framework based on domestic CAD/CAM software system, which contributes to the further research to develop the domestic software system applied in restorative dentistry.

Methods: Point cloud data of a partially edentulous cast, a mandibular Kennedy Class II modification 2 arch, was captured by an optical scanning system with projective grating and high-resolution digital camera. Using domestic CAD/CAM software system, the above point cloud data was reduced, digital surveying line and inserting path were determined.

[Effect of bite force lost on the expression of iNOS in the rat periodontium].

Purpose: To investigate the molecular mechanism of the effect of bite force loss on periodontium remodeling.

Methods: For establishing a rat model of different bite forces for the study, the left maxillary molars of Wistar rats were extracted and the left mandibular molar area was used as the model of the bite force lost. The animals were sacrificed after 6 hours,1,2,3 days and 1,2,3,4weeks.

[Evaluating the integrated force induced by high quality magnet and elastics in orthodontic fixed appliance].

Purpose: To investigate the stability and effective working distance of integrated forces induced by high quality magnet and elastics in orthodontic fixed appliance.

Methods: N48 NdFeB magnets resembling brackets in size and volume were combined with 1/8, 3/16, 1/4, and 3/8 inch orthodontic elastics respectively to induce integrated forces that had super-long working distance. Magnetic, elastic, and integrated forces were tested by universal material test system and curves of the forces were draw.

[Weibull analysis and flexural strength of glass-infiltrated alumina composite machined by CAD/CAM].

Purpose: To explore the structural reliability of machined infiltrated ceramic made from ultrafine alumina powder for dental CAD/CAM by means of flexural strength together with Weibull analysis.

Methods: Ultrafine grain-sized alumina powder made from ammonium aluminum sulfate was sintered into one kind of porous machined ceramic block. After being infiltrated by lanthanum glass powder, a glass infiltrated alumina composite was produced.

[The use of modified inlay in restoration of posterior molars with large defect].

Purpose: This study evaluated the clinical effectiveness of Co-Cr alloy inlays/onlays in the restorations of posterior teeth with large defects.

Methods: 96 inlays were examined in 83 patients. The interval between placement and assessment was 6 months,1 year and 2 years.

[Effects of bovine plasma fibronectin on the proliferation of rat osteoblast in vitro].

Objective: To investigate the effects of bovine plasma fibronectin on the proliferation of rat osteoblast in vitro.

Methods: Cell cultured. AlamarBlue were used to determine the effect of various concentration of bovine plasma fibronectin on the proliferation of rat osteoblast in vitro.