Corrosion behaviors of TiO2 nanotube layers on titanium in Hank's solution.

It is well known that the growth of osteoblast cultured on titanium with nanotube layers can be significantly increased compared to unanodized surfaces. In the current study, the corrosion behavior of titanium with nanotube layers was studied in naturally aerated Hank's solution using open circuit potentials (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests. The electrochemical results indicated that TiO2 nanotube layers on titanium showed a better corrosion resistance in simulated biofluid than that of smooth-Ti.

Evidence for calcifying nanoparticles in gingival crevicular fluid and dental calculus in periodontitis.

Background: Calcifying nanoparticles (CNPs), also known as nanobacteria, can produce carbonate apatite on their cell walls and initiate pathologic calcification. The objective of this study was to determine whether CNPs are present in the gingival crevicular fluid (GCF) from subjects with periodontal disease and whether they can induce the pathologic calcification of primary cultured human gingival epithelial cells.

Methods: GCF and dental calculus samples were collected from 10 subjects with gingivitis and 10 subjects with chronic periodontitis.

Sonic hedgehog alleviates the inhibitory effects of high glucose on the osteoblastic differentiation of bone marrow stromal cells.

To assess the influence of high extracellular glucose levels on the osteogenic differentiation of bone marrow stromal cells (BMSCs) and to determine if Sonic hedgehog (Shh) protein can alleviate those effects. BMSCs were incubated with NG (normal glucose), NG+Shh (200 ng/ml Shh in normal glucose), NG+Shh+Gan (200 ng/ml Shh and 5 micromol/L GANT61 in normal glucose), HG (high glucose), HG+Shh (200 ng/ml Shh in high glucose), and HG+Shh+Gan (200 ng/ml Shh and 5 micromol/L GANT61 in high glucose). The expression levels of Shh signaling pathway genes Patched 1 (PTCH1) and osteogenesis-related genes were tested, which included bone morphogenetic protein 4 (BMP4), runt-related transcription factor 2 (Runx2), and osteopontin (OPN).

[The antibacterial activity of plasma sprayed silver-containing hydroxyapatite coatings].

Purpose: To study the antibacterial activity of plasma sprayed silver-containing hydroxyapative(HA) coatings.

Methods: Silver-containing HA coatings were prepared on titanium substrated by vacuum plasma spraying (VPS). The samples were divided into 4 groups according to weight percent of the antimicrobial: group HA0 (0%),group HA1 (1%),group HA3 (3%) and group HA5 (5%).

Cyclic stretching force induces apoptosis in human periodontal ligament cells via caspase-9.

The response of periodontal ligament (PDL) cells to mechanical stimulation is important in the periodontal tissue remodelling. Our previous study showed that cyclic stretching force on PDL cells induced early apoptosis. However, the mechanism of stretching force-induced cell death is unclear.

Lack of effect of habenula lesion on heroin self-administration in rats.

We examined the effects of bilateral electric lesion of the habenula (Hb) on the acquisition and maintenance of heroin self-administration. The rats were trained to self-administer heroin (0.05 mg/kg/infusion) under FR1 schedule in daily 4h sessions.

[Study on the slow release of silver ion from silver containing antibacterial HA coating material].

Purpose: To study the slow release of silver ion from silver containing antibacterial HA coating material.

Methods: Ti coated with HA samples were prepared using vacuum plasma spraying. In group 1, HA coating materials contained 5%(wt%) silver-zirconium phosphate antimicrobial.

[A primary study of color tolerance of anterior tooth crown prosthesis].

Objective: To study the color tolerance of anterior ceramic crown and seek an effective approach for color-matching of oral prostheses.

Methods: 30 single maxillary incisor ceramic prostheses and the corresponding nature teeth were measured by a digital camera in a steady environment for image taking and color measurement, which based on the standard recommended by CIE. The color tolerance was analyzed in two groups based on satisfaction and dissatisfaction of prostheses color-matching.

Effects of training and withdrawal periods on heroin seeking induced by conditioned cue in an animal of model of relapse.

Rationale: A high incidence of relapse can be triggered by exposure to conditioned cues previously associated with heroin. Extended access to drug and withdrawal are thought to affect the motivation for drug seeking.

Objectives: The present study evaluated how different periods of training to self-administer heroin and different periods of withdrawal affected drug seeking.

[Comparison of clinically used shade guide systems with color range of natural teeth].

Objective: To analyze the limitation of currently used shade guide systems comparing with color range of nature teeth.

Methods: Digital pictures of shade guide systems A (VITAPAN Classic), B (VINTAGE Halo), C (3D-MASTER), and 322 central incisors were taken under the same condition as light source of D65 with the observation method of d/0 degrees. The data obtained from nature tooth color were compared with the color range of three shade guide systems mentioned above in items of L * a * b */C * H degrees.

[Clinical application of custom-made key-key attachment in the restoration of maxillofacial defect].

Purpose: To evaluate the usefulness of custom-made key-key attachment in restoration of maxillofacial defect.

Methods: Using key-key attachment, facial prostheses and intraoral prostheses were combined to restore dentition, maxilla and right facial defects in a female patient.

Results: Good retention of maxillofacial prostheses and intraoral prostheses were obtained.

A "teardown" method to create large mesotunnels on the pore walls of ordered mesoporous silica.

A "teardown" method to create large mesotunnels (approximately 9 nm) on the pore walls of ordered mesoporous silicas is demonstrated by digesting the organic constituents from polymer-silicate nanocomposites. The ordered mesostructured polymer-silicate composites were first obtained via the evaporation-induced triconstituent co-assembly method by using a low-molecular-weight phenolic resin (resols) as an organic precursor; prehydrolyzed TEOS as an inorganic precursor, and triblock copolymer F127 as a template. All of organic components including F127 and phenolic resins are removed by the microwave digestion (MWD) method from mesostructured polymer-silica composites.

[Three-dimensional finite element analysis of the influence of implant location on the stress distribution for implant-supported fixed partial dentures].

Purpose: To evaluate the influence of implant location on the stress distribution for implant-supported fixed partial dentures by 3-D finite element analysis.

Methods: Four 3-D finite element models with different implant location were constructed. Four different loading conditions(vertical distributed,oblique distributed,vertical concentrated,oblique concentrated) were applied to investigate the stress distribution by finite element analysis software ABAQUS 6.

[The effect of tooth preparation design on the CEREC all-ceramic crown's marginal adaptation].

Purpose: To study the effect of tooth preparation on marginal adaptation of all-ceramic crown designed by the Cerec system.

Methods: Lower first molar in the standard model was prepared into four types, two occlusal convergences (6 degrees and 12 degrees ) and two marginal shapes (chamfer and shoulder), and then divided into four groups correspondingly with 8 copies of abutment preparation test piece in each group. All-ceramic crown was designed by the Cerec 3 system and inserted with corresponding test piece.

[Effect of two-step sintering method on properties of zirconia ceramic].

Objective: To study the influence of two-step sintering method on the sintering property, mechanical properties and microstructure of zirconia ceramic.

Results: The nano-size zirconia powder were compacted and divided into two groups, one group for one-step sintering method, another group for two-step sintering method. All samples sintered at different temperature.

[Effect of electroacupuncture on drug-seeking behaviors induced by heroin priming and FosB expression in relevant brain regions].

Objective: To explore the effect of electroacupuncture on heroin seeking behavior and FosB expression in relevant brain regions.

Methods: Rat model of heroin relapse behaviors was developed with progressive fixed ratio program,and model rats were randomly divided into 3 groups: a restraint group, a needle retention group, and a electroacupuncture group. The heroin seeking behavior was elicited by a small dose of heroin.

[Preparation of hydroxyapatite-containing titania film on the surface of pure titanium by micro-arc oxidation technique].

A porous hydroxylapatite-containing titania film was prepared by an electrochemical oxidation method, i.e. micro-arc oxidation (MAO).

[Effect of position of artificial occlusal interference on mandible moving track during lateral movement].

Purpose: To evaluate the effect of position of occlusal interference on the track of mandibular incisal point during lateral movement.

Methods: The changes of track of mandibular incisal point along with the changing of occlusal interference position were recorded by Arcus DigMa mandibular moving track analysis system. The relativity between occlusal interference position and mandibular incisal point moving track on arrowy axis, vertical axis and horizontal axis was analyzed.

[Fabrication and physical properties of porous individual beta-TCP scaffold to reconstruct residual alveolar ridge in dog].

Purpose: To fabricate porous individual beta-tricalcium phosphate scaffold and test its properties in dog.

Methods: A model of residual alveolar ridge in mandible of a dog was made and CT scanned after 3 months.The data of CT was transformed to 3-D format by MIMICS 7.

[Effects of mechanical stretching on intercellular free calcium concentration of human periodontal ligament cells].

Purpose: The purpose of this study is to investigate the effects of mechanical stretching on the concentration of free calcium in the human periodontal ligament cells(HPDLCs).

Methods: HPDLCs were cultured in vitro, and cells which were divided into strain 1%, 10% and 20% group were stretched by dynamic mechanical strain unit for 30,60 and 120 minutes,respectively. Free calcium concentration was examined through flow cytometry and laser scanning confocal microscope.

[A static magnetic field loading system for in vitro cultured cells].

Magnetic attachments have flux leakages, thus they will exert certain magnetic fields on the adjacent tissues when used in the patients' oral cavities. There are few research reports on the biological effects of the magnetic fields generated by magnetic attachments on human body. A cellular static magnetic field (SMF) loading system was developed in this study.

Magnetic fields of 10mT and 120mT change cell shape and structure of F-actins of periodontal ligament cells.

Dental magnetic attachments, usually applied locally to oral cavities, produce stray fields (flux leakage) spreading in adjacent tissues. It has been found that human periodontal ligament (PDL) cells change their geometry and the structure of their cytoskeleton F-actins when the cell cultures are exposed to B-field strengths of B = 10mT and 120mT, respectively, which are similar to those generated by dental magnetic attachments. Analytically, after long-time exposures to B-fields for 12h, 36 h and 60 h, respectively, cytoskeleton F-actins are labeled with a fluorescent dye and observed under a laser scanning confocal microscope.

[Analysis of Chinese literatures on evidence-based dentistry between 2001 and 2006].

Purpose: To explore the research trends and statuses of evidence-based dentistry.

Methods: Analyzing the articles related with EBD from 2001-2006 by bibliometrics, which were CNKI database.

Results: 74 articles were found out from the database.

[Influence of time on shear strength using resin cements].

Purpose: To compare the shear bond strength of different composite resin cement systems at different time intervals.

Methods: 48 healthy non-carious human molars were selected in the study. The samples were divided into two groups, 24 in each group.

[A preliminary study on maxillofacial prosthesis using structured light three-dimensional scanning and rapid prototyping technique].

Objective: To evaluate application of three-dimensional reconstruction of the facial soft tissue by use of light three-dimensional scanning system and rapid prototyping and to lay a foundation for developing the computer aided design (CAD) and computer aided manufacture (CAM) system of the maxillofacial defect rehabilitation.

Methods: The left and right facial profiles of a volunteer were scanned with the light three-dimensional scanning system that was a self-developed one. The complete point and cloud data were obtained by transforming the image data with the Surfcaq software.