[An evaluation of fiber reinforced composites veneer in anterior esthetic restoration].

PURPOSE: To explore the advantages of fiber reinforced composites veneer in repairing discolorated and defective anterior teeth. METHODS: Twenty porcelain veneers and 20 fiber reinforced composites veneers specimens of 2 cm long, 2 cm wide and 1 mm in thickness, with a longitudinal cross section of 45° incline were made. Another 40 fiber reinforced composites specimens of the same shape were used for comparison. After polishing and acid treatment of all the specimens according to clinical routine, resin cement was used for bonding the porcelain cover with resin veneers slope, and the conjunct specimens were soaked in 40 ℃ warm water for 24 h and drying; then the two groups of specimens were put were put on the pressure testing platform of the universal testing machine, with 1 mm/min testing pressure, and 1 cm2 square head was contacted on the surface of the bonding interface. Computer was used to record the fracture process of the two groups of specimens and the maximum compressive strength of bonding interface automatically. The compressive strength of the bonding interface under the same conditions was evaluated. SPSS 12.0 software package was used for statistical analysis. RESULTS: The compressive strength of the bonding interface between fiber reinforced composites was significantly higher than that between porcelain and fiber reinforced composites(P<0.05). CONCLUSIONS: Compared with porcelain veneers that can not be repaired when damaged in the anterior teeth, high-strength fiber resin veneers can partially be repaired with the same material, which has obvious advantages.

[rhPDGF-BB promotes migration of bone marrow stromal stem cells in diabetic rats].

PURPOSE: To evaluate the effect of different concentrations of rhPDGF-BB on bone marrow stromal stem cells(BMSCs) migration in diabetic rat, and related mechanisms of SDF-1 and its G-protein conjugated receptor regulation, provide a theoretical basis for the application of rhPDGF-BB to diabetic patients for bone regeneration therapy. METHODS: Animal model with diabetes were induced by streptozotocin in rats. BMSCs of diabetic rats were cultured in vitro as the control group. Transwell chemokinesis model was adopted to detect the chemokinesis of BMSCs in vitro with rhPDGF-BB at concentrations of 0, 10, 50, and 100 ng/mL, and real-time PCR was used to detect the expression of BMSCs SDF-1, CXCR4 mRNA, determine the optimum concentration of the drug. The regulatory effects of rhPDGF-BB on SDF-1 and CXCR4 expression of BMSCs were confirmed in reverse with PI3K/Akt inhibitor. Statistical analysis of the data was performed using SPSS 17.0 software package. RESULTS: In diabetic rats induced by streptozotocin, one week later, the rat tail vein blood glucose concentration higher than 16.7 mmol/L was selected as the successful model rats. Compared with BMSCs in diabetic rats, rhPDGF-BB promoted BMSCs migration in diabetic rats, 50 ng/mL rhPDGF-BB was the optimal concentration in diabetic rats, and PI3K/Akt inhibitors significantly inhibited the migration of BMSCs in diabetic rats. CONCLUSIONS: rhPDGF-BB promotes the migration of diabetic rat BMSCs and regulates its migration by regulating SDF-1/CXCR4 axis.

[3-D reconstruction of the maxillary central incisor by digital camera].

PURPOSE: To evaluate the role of digital camera in reconstruction of 3-D solid model of the maxillary central incisor. METHODS: Photographs of each section of the maxillary central incisor were taken with digital camera, then the 3-D model was reconstructed with photoshop software and 3DMAX software. RESULTS: The precise 3-D solid model of the maxillary central incisor was successfully reconstructed. CONCLUSIONS: 3-D reconstruction of the maxillary central incisor can be completely accomplished by dentists themselves.