OBJEVTIVETo evaluate the effect of different restoration methods on fracture resistance of endodontically treated teeth.

METHODSFifty intact extracted maxillary first premolars were randomly divided into 5 groups. Medial-occlusal cavity models were established in all the test groups (B-E) according to the same standard, followed by treatments with defect exposure only, defect filling with light cured composite resin, indirect resin inlays, or light cured composite resin combined with Biosplint fiber. Each specimen was tested using a universal test machine at 1.00 mm/min until fracture and the fracture load was recorded. The load angle was 45 degree to the long axis of the teeth, and the load was pointed to the middle of the lingual surface on the buccal cusp. The fracture resistance was analyzed statistically.

RESULTSThe mean load to cause fracture of the samples in each group group A to E was 1.27∓0.41, 0.23∓0.17, 0.55∓0.31, 0.89∓0.40, and 0.98∓0.34 kN, respectively, showing significant differences between the groups.

CONCLUSIONThe fracture resistance of the teeth is reduced after endodontic therapy, but can be increased significantly by restoration with composite resin inlay or light cured composite resin combined with Biosplint fiber.

Bicuspid ; physiopathology ; Composite Resins ; chemistry ; Dental Materials ; chemistry ; Dental Restoration, Permanent ; methods ; Dental Stress Analysis ; Humans ; Inlays ; Maxilla ; Tooth Fractures ; physiopathology ; Tooth, Nonvital ; physiopathology ; therapy

Ethanol is one of the major risk factors for esophageal cancer.The main mechanisms of ethanol induced esophageal cancer include the direct carcinogenesis of acetaldehyde,the genetic polymorphism of enzymes related to alcohol metabolism,the carcinogenic effect of reactive oxygen species,the disorder of nutrient metabolism induced by ethanol,and the synergistic effect of ethanol and tobacco.

Syphilis can not be cultured in vitro.So far, serologic testing is still regarded as the mainstay for diagnosing syphilis and for monitoring the efficacy of subsequent antibiotic treatment.However, single serological tests have limitations in sensitivity or specificity.Detective algorithms with two or more serological methods will help to improve the effectiveness of syphilis diagnosis, and decrease missed diagnosis and misdiagnosis.This article will review advances on etiological examination, serological tests, and detective algorithms for syphilis.In particular, it specially introduces the merits and demerits of three detective algorithms for syphilis,so as to explore suitable screening methods,and provide basis for relevant administrative departments to formulate related laws, regulations and guidelines for syphilis.

The aim of this study is to quantify the 146S antigen in foot-and-mouth disease virus (FMDV) inactivated vaccine by size-exclusion chromatography (SEC). The analysis was performed on a TSKgel G4000SWXL column (7.8 mm×30 cm), with a pH 7.2 buffer salt system as the mobile phase. The flow rate was 0.6 mL/min, the injection volume was 100 μL and the detection wavelength was 259 nm. The calibration curve was established by using purified inactivated FMDV (serotype O) 146S antigen; 3 batches of vaccine formulated by inactivated antigen solution were tested to verify the accuracy, reproducibility, specificity and tolerability of the method. At last 16 batches of vaccine were determined by the SEC method. Results showed a good linearity between peak area and concentration of 146S antigen in the range between 0.56 and 67.42 μg/mL (R2=0.996, n=10), and the average recovery rate of 146S antigen in the 3 batches of vaccine formulated in lab were 93.6% (RSD=2.7%, n=3), 102.3% (RSD=2.6%, n=3), and 95.5% (RSD=5.1%, n=3). The method was proved accurate and reliable with good reproducibility (RSD=0.5%, n=6), and applied to determine 16 batches of the commercial FMDV vaccine. According to the above results, the SEC method is high effective for 146S antigen quantify in the inactivated FMDV vaccine and would provide strong support for the vaccine quality control.