OBJECTIVETo evaluate the metal-ceramic bond strength of a selective laser melting Co-Cr alloy.

METHODSTwelve Co-Cr metal bars were prepared according to the ISO 9693 standard with Vita porcelain fused onto the centre of each bar. Then the sample bars were divided into two groups of six each. The control group was made by traditional cast process (cast group), and the experimental group was processed by selective laser melting (SLM) technology (SLM group). Metal-ceramic bonding strength and fracture mode were assessed using three-point bending test. Fracture mode analysis was determined by scanning electronic microscope/energy dispersive spectroscopy. Student's t-test was used to analyze the data in SPSS 13.0.

RESULTSThe metal-ceramic bond strength value of the cast group was (33.45 ± 2.34) MPa, and that of the SLM group was (31.62 ± 2.34) MPa (t = 0.79, P > 0.05). A mixed fracture mode on the debonding interface of all specimens was observed, while little porcelain was reserved.

CONCLUSIONSThe metal-ceramic system processed by SLM exhibited a bonding strength that satisfies the requirement of clinical application.

Chromium Alloys ; Compressive Strength ; Dental Casting Technique ; Materials Testing ; Metal Ceramic Alloys

OBJECTIVEThis study was intended to design a kind of resisting part dint of device in order to preventing the base plate break while being subjected to the dint when partial base plate dint concentrates because of the increase of the magnetic attachment to the original movable artificial teeth.

METHODSTen patients who should increase magnetic attachment was adopted in the study, and we increased a kind of new designed partial cast base plate on the original base plate using laser welding technique, then designed magnetic attachment and artificial teeth.

RESULTSNone of ten sufferers appeared the phenomenon of the break of the base plate.

CONCLUSIONThe application of the laser welding technique can prevent the break of the base plate when partial dint increase because of the increase of the magnetic attachments.

Dental Soldering ; Humans ; Lasers ; Magnetic Phenomena ; Magnetics ; Welding

OBJECTIVETo study the color reappearance effect of metal-ceram restoration and foundry-ceram restoration using Crystaleye spectrophotometer.

METHODS58 metal-ceram restorations and 58 foundry-ceram restorations according to the result of the Crystaleye spectrophotometer were made respectively. The deltaE between restorations and natural teeth as referenced were analyzed. And satisfaction of dentists and patients were evaluated.

RESULTSThe deltaE between metal-ceram restorations and natural teeth was 7.13 +/- 0.74. The deltaE between foundry-ceram restorations and teeth was 1.47 +/- 0.84. There were statistical differences between the deltaE (P < 0.01). The satisnatural faction of dentists and patients to the foundry-ceram restorations were higher than to the metal-ceram restorations (P < 0.05).

CONCLUSIONCrystaleye spectrophotometer can provide accurate reference for foundry-ceram restoration, but for metal-ceram restoration it is not accurate.

Color ; Humans ; Metals ; Spectrophotometry ; Tooth

OBJECTIVETo investigate effects of the leaching liquids of 5 different kinds of dental alloys on L929 cells at cell level and molecular level.

METHODSThe fibroblast L929 cells of mouse were cultivated in vitro in leaching liquids of 5 different kinds of dental alloys, Au alloy (n = 8), Ag-Pt alloy (n = 8), Co-Cr alloy (n = 8), Ni-Cr alloy (n = 8), and Cu alloy (n = 8). The RPMI 1640 cell medium containing 10% fetal beef serum was used as control. The cytotoxicities of the 5 dental alloys were evaluated by means of methyl thiazolyl tetrazolium (MTT), and the effects of these alloys on the expression of caspase-3, caspase-8, and caspase-9 mRNA of L929 cells were examined using reverse transcription polymerase chain reaction (RT-PCR) method.

RESULTSAfter 48 hours culture the cytotoxicity of Cu alloy group was in Grade 4 and those of the other groups were all in Grade 0. The mRNA levels of caspase-8 had no change in all groups (P > 0.05). The mRNA levels of caspase-3 were as follows: Cu alloy (0.474 +/- 0.001), the negative control (0.527 +/- 0.003), Au alloy (0.528 +/- 0.013), Co-Cr alloy (0.615 +/- 0.007), Ag-Pd alloy (0.673 +/- 0.009), and Ni-Cr alloy (0.803 +/- 0.037). The mRNA levels of caspase-9 were as follows: Cu alloy (0.532 +/- 0.041), Au alloy (0.574 +/- 0.013), the negative control (0.578 +/- 0.010), Co-Cr alloy (0.617 +/- 0.009), Ag-Pd alloy (0.703 +/- 0.018), and Ni-Cr alloy (0.811 +/- 0.037). There were significant differences between the groups except the negative control group and Au alloy group.

CONCLUSIONSThe Cu alloy shows the highest cytotoxicity, and the leaching liquids of 5 different kinds of dental alloys may induce cell apoptosis through mitochondrion pathway.

Animals ; Apoptosis ; drug effects ; genetics ; Caspase 3 ; genetics ; metabolism ; Caspase 8 ; genetics ; metabolism ; Caspase 9 ; genetics ; metabolism ; Culture Media ; Dental Alloys ; pharmacology ; L Cells (Cell Line) ; Materials Testing ; Mice ; RNA, Messenger ; metabolism

OBJECTIVETo study the bonding capability when Ni-Cr porcelain alloy was added with Ti, compound rare earth metals and removed the element of Be.

METHODSNi-Cr-Ti porcelain alloys manufactured by Institute of Metal Research of Chinese Academy of Sciences were tested. The test alloys were divided into three groups according to whether containing Be and compound rare earth metals or not. And HI BOND Ni-Cr base-metal alloy was chosen as control. The metal-ceramic specimens were prepared for shear test, scanning electron microscope (SEM) and energy spectrum analysis.

RESULTSThe shear bond strength of the four groups were analyzed. No significant difference were observed among them (P > 0.05). No crackle was found and they were contacted tightly between the porcelain and metal. The composition and contents of the four groups' interfaces were closed.

CONCLUSIONThe shear bond strength of the self-made Ni-Cr-Ti porcelain alloys all can satisfy the clinical requirements. Experimental groups containing Ti, compound rare earth metals and removing the element of Be can be used as better recommendation for clinical practice.

Alloys ; Ceramics ; Chromium Alloys ; Dental Alloys ; Dental Bonding ; Dental Porcelain ; Humans ; Nickel ; Titanium

OBJECTIVETitanium, by far one of the oldest materials in medical implants used for hard tissue replacement and rehabilitation, was used widely as implant material. The objective of the present study was to fabricate the TiN modified layer on the surface of medical pure titanium and improve its surface properties. Thus the wear resistance, biocompatibility and antisepsis were improved.

METHODSA continuous-wave 2 kW Nd: YAG laser was used to irradiate the sample in the environment of N2 with concentration of 99.995%. Titanium nitride surface coatings had been extensively used as corrosion resistant and biocompatible layers on titanium and its alloys. The microstructure and composition of the laser nitrided coating were studied by scanning electron microscopy and X-ray diffraction. Microhardness of the modified sample was also analyzed by micro-hardmeter.

RESULTSTiN modified layer with the thickness of about 400 microm was obtained. TiN distributed gradually from surface to the substrate. There was a good metallurgical bonding between the nitrided layer and the substrate. The hardness of the modified layer was reduced from the surface to the inside.

CONCLUSIONWith optimum process parameters, a compact laser modified gradient coating reinforced with fine TiN was achieved on the surface of medical titanium.

Biocompatible Materials ; Corrosion ; Lasers ; Materials Testing ; Microscopy, Electron, Scanning ; Prostheses and Implants ; Surface Properties ; Titanium ; X-Ray Diffraction

OBJECTIVETo evaluate the application of ultrasonography in diagnosis and treatment of the upper arm radial neuritis.

METHODSFrom 2005.12 to 2011.7, 10 patients of the upper arm radial neuritis were selected and included 6 males and 4 females with an average age of 32 years old ranging from 20 to 40 years. The course of disease ranged from 4 months to 2 years. All patients feel pain on the outside of upper arm. Medical examination showed Tinel's sign masculine, and the muscle force included extension of wrist and fingers were reduced. Upper arm radial neuritis were diagnosed by clinical sign and medical examination. All patients underwent ultrasonography examination, electrophysiology examination and operation. The ultrasonography were compared to the results of electrophysiology examination,and ultrasonography were compared to intra-operative findings and pathology examination.

RESULTSThe ultrasound images showed average diameter of affected limb radial nerve were (0.29+/-0.04) cm, average area were (0.23+/-0.05) cm2, and all of these were greater than uninjured side. Ultrasonograghic findings and orientation of radial neuritis were consistent with intra-operative findings,and the results of ultrasonography were consistent with the results of pathology examination.

CONCLUSIONUltrasonography examination provide morphological evidence for the diagnosis and treatment of the upper arm radial neuritis.

Adult ; Female ; Humans ; Male ; Neuritis ; diagnostic imaging ; pathology ; physiopathology ; therapy ; Radial Nerve ; diagnostic imaging ; Ultrasonography

OBJECTIVETo introduce the experience in the treatment of lower eyelid pouches orbital rim.

METHODSAn incision was made along the margin of lower eyelid and dissection was performed under the orbicularis muscle to expose the orbital septum and periosteum of lower orbital rim. The fat released from orbital septum was transposed just below the lower orbital rim and fixed on the periosteum. If lacrimal groove deformity was not corrected completely, the musculocutaneous flap, which may be excised beside the incision, was kept to correct the deformities further with only the muscle portion.

RESULTS72 cases with lower eyelid pouches complicated with lacrimal groove deformities were treated with transposition of orbital fat and orbicularis muscular flaps. Satisfactory results were achieved in all the patients after a follow-up period of 3-6 months.

CONCLUSIONIt is an effective and feasible technique to correct lacrimal groove deformities with transposition of orbital fat and orbicularis muscular flaps.

Adipose Tissue ; transplantation ; Aged ; Blepharoplasty ; methods ; Eyelids ; surgery ; Humans ; Orbit ; Periosteum ; surgery

OBJECTIVETo investigate the clinical results of the treatment of severe infantile hemangioma with high-dose propranolol in Chinese.

METHODS56 cases with severe infantile hemangioma were treated with propranolol. Clinical evaluation, electrocardiography, and experimental examination of liver function and heart function were performed before treatment. The daily dose of propranolol was increased from 1 mg/kg at the first day to 1.5 mg/kg at the second day, and to 2 mg/kg at the third day. The propranolol was given twice a day. The treatment was lasted for six months. The patients were visited every month.

RESULTSThe lesion color was changed after 2-4 days of treatment in all the cases. All the lesions were dramatically improved after one month of treatment. The ulceration were healed, except one case. Until now, complete regression was achieved in 10 cases and marked improvement in 46 cases. Side effects were happened in 3 cases, including one case of abnormal liver function, one case of CK-MB increase and one case of continuous increase of CK-MB, LDH, ALT, GGT.

CONCLUSIONSHigh-dose Propranolol is very effective in the treatment of infantile hemangioma with minor side effects and short disease period. It might he used as the first-line treatment for infantile hemangioma.

China ; Female ; Hemangioma ; drug therapy ; Humans ; Infant ; Male ; Propranolol ; administration & dosage ; therapeutic use ; Treatment Outcome

OBJECTIVETo compare curative effect between complete denture with lingualized occlusion and anatomic occlusion on temporomandibular joint disorders (TMD) of aged edentulous patients with severe residual alveolar ridge resorption.

METHODSSeventy aged edentulous patients with severe residual alveolar ridge resorption were recruited in this study and randomly assigned into two groups, thirty-five each. In Group A, patients received complete denture with lingualized occlusion, and in Group B, patients received complete denture with anatomic occlusion. The condition of TMD was examined and recorded by the same TMD specialist at baseline, 3 months and 6 months following denture delivery. The recovery effect of TMD was evaluated according to Fricton Index. Related data were analyzed statistically with t-test and rank sum test.

RESULTSThree months following denture delivery, the craniomandibular index (CMI) decrease value was (0.064 ± 0.022) in group A, and was significantly higher than that in group B (0.043 ± 0.018) (P < 0.01). Six months following denture delivery, the CMI decrease value was (0.084 ± 0.020) in group A, and was significantly higher than that in group B (0.070 ± 0.021) (P = 0.011<0.05).

CONCLUSIONSComplete denture with lingualized occlusion may be more conducive to the remission of TMD for aged edentulous patients with severe residual alveolar ridge resorption.

Aged ; Aged, 80 and over ; Dental Occlusion ; Dental Occlusion, Centric ; Denture, Complete ; Female ; Humans ; Jaw, Edentulous ; complications ; Male ; Temporomandibular Joint Disorders ; etiology ; therapy