Objective:To combine the cold lateral condensation with System B root canal filling techniques in order to increase the amount of gutta-percha to fit different canal that could improve percentage of gutta-percha-filled area(PGFA)and decrease the probability of apical extrusion. Methods: Two groups of extracted human canines (total 80) were prepared by modified double-flared technique and filled with gutta-percha by System B technique and the combined technique respectively. The overfilling samples were collected. A horizontal section was cut 1.5 mm from the apical foramen of each tooth. The cross-sectional area of the canal and the gutta-percha was measured using an image-analysis program. The PGFA was then calculated. Results:Overfilling rate in the combined technique group was significantly lower than that of the control group (P

Objective:To compare quantitatively the quality of the canal isthmus retropreparation among three kinds of ultrasonic ret-rotips.Methods:1 20 maxillary bicuspid teeth with two canals and an isthmus were randomly assigned to 3 groups(n=40).The canal isthmus retropreparation were made respectively using ultrasonic niti tip RE2,diamond tip Berutti and #25K file.Image processing and analysis system were used to measure the preoperative and postoperative parameters for further evaluation.Results:The cutting volume of ultrasonic niti tip RE2 group was significantly less than those of other two groups(P<0.05).Conclusion:Ultrasonic niti tip RE2 is feasible in the canal isthmus retropreparation.

Objective:To compare the quality of root-end preparation quantitatively between ultrasonic retrotips and traditional slow-speed handpiece. Methods: 27 maxillary second bicuspid teeth with two canals and an isthmus were randomly assigned to 3 groups.Root-end preparations were made respectively using ultrasonic diamond tip Berutti and niti tip RE2, ultrasonic 40~#K file and slow-speed handpiece with No.2 round bur. Image processing and analysis system were used to measure the preoperation and postoperation parameters for further evaluating the difference between the two techniques. Results: The cutting volume of ultrasonic instruments was less than slow-speed handpiece(P<0.000 1). Conclusion: Ultrasonic instrument is better in the root-end preparation than traditional slow-speed handpiece.

ObjectiveTo analyze the effects of three different display devices on the interpretation of imaging data in medieal imaging system.MethodsThe luminance-meter L100 and the test patterns provided by the American Association of Physicists in Medicine(AAPM)were used to assess the performance of three display devices(the spherical,flat panel and liquid crystal display devices).The corresponding luminance response was compared with the reference criteria provided by AAPM Task Group 18(AAPM TG18).DR chest photography was taken on CDRAD2.0 contrast-detail phantom using the following experimental parameters:100 mA,80 kVp,and the exposure times for 6,10,12,and 16 ms.After each exposure,the surface dose of phantom was recorded and the image quality factor(IQF)was calculated.Statistical analysis of IQF was performed using ANOVA. ResultsThe maximum luminance values in the spherical,flat panel and liquid crystal display devices were 170,59 and 231 cd/m2 and the luminance ratio was 257, 99 and 350 respectively.There was a significant difference in the IQF bewteen the liquid crystal display device and other two display devices.Conclusion The liquid crystal display device has the better image quality.

OBJECTIVE:To explore the correlation between ornidazole (ONZ) salivary concentration and plasma concentra-tions in healthy subjects,and to provide reference for clinical therapeutic drug monitoring. METHODS:24 healthy volunteers were selected. After oral administration of ONZ capsules 1.00 g,their venous blood and saliva were collected at 0.25,0.5,1.5,5.5, 10.5,24.5 and 43.5 h after medication. HPLC method was used to determine the plasma and salivary concentrations of ONZ. The correlation between the two was analyzed. RESULTS:The peak values of plasma and salivary ONZ concentrations appeared imme-diately at 1.5 h after administration and the peak values were(0.96±0.15)μg/ml and(0.93±0.15)μg/ml;salivary concentration of ONZ was lower than plasma concentration at each time points,but there was no statistical significance (P>0.05);the regres-sion equation of salivary ONZ concentration and plasma concentration was csaliva=1.176 5cplasma-0.199 4(r=0.990 1). The ratio of salivary concentration and plasma concentration of ONZ (S/P) was (0.91 ± 0.06),showing positive correlation (r=0.632-0.970, P<0.05). CONCLUSIONS:The salivary ONZ concentration is significantly correlated with plasma concentration in healthy peo-ple,so saliva can be used for therapeutic drug monitoring.

Objective:To compare the quality of the canal isthmus retropreparation among three ultrasonic retrotips.Methods:120 maxillary bicuspid teeth with 2 canals and an isthmus were randomly assigned to 3 groups(n =40).The canal isthmus were retro-preparated by ultrasonic Ni-Ti tip RE2,diamond tip Berutti and #25K file respectively.The quality of cavity margin,the number and type of the micro-cracks were evaluated by SEM.Data were statistically analysed by Kruskal Wallis Test of SPSS 13.0.Results:The cavity margin quality of ultrasonic Ni-Ti tip RE2 group was superior to that of other 2 groups(P =0.003);The number of micro-crack in Ni-Ti tip RE2 group was less than that of other 2 groups(P =0.003).The type of micro-cracks has no significant difference among the 3 groups(P =0.830).Conclusion:Ultrasonic Ni-Ti tip RE2 is feasible in the canal isthmus retropreparation.

Objective:To evaluate the sealing ability of the 3.0th generation of polyamidoamine dendrimer(3.0 PAMAM)on hu-man dentinal tubules.Methods:1 6 extracted premolars were cut into 2 mm thick dentin slices to establish sensitive dentin model in vitro.Then 2 samples without any treatment were selected randomly into demineralized dentin group,and the remain 1 4 dentine pills were divided into 2 groups by the random number table(n=7).Samples in the experimental group were treated with 3.0 PAMAM, those in the control group were treated with deionized water.After having immersed in the artificial saliva for 2 and 4 weeks respec-tively,the dentin slices were examined by scanning electron microscope(SEM)and X-ray energy dispersive spectroscopy(EDS). Results:SEM showed that the minerals on the surfaces of the dentine disks in experimental group were formed gradually with the time,the dentinal tubules were blocked 4 weeks after treatment.The minerals on the sample surface in control group were less and the dentinal tubules remained open.EDS results showed that Ca/P(1 .49 ±0.1 6)of mineral deposition in the experimental group was higher than that in the control group (1 .1 8 ±0.20)(P<0.05).Conclusion:The 3.0th generation of PAMAMhas the occlu-ding ability by inducing remineralization on the dentine surface and it may be used in the treatment of dentin hypersensitivity.

Purpose To study the clinic-pathological features, differential diagnosis and prognosis of extragastrointestinal stromal tumor ( EGIST) arising in the vulva and the rectovaginal septum. Methods Clinical manifestations, pathological features, immunohisto-chemistry, gene mutations, treatment and prognosis were analyzed in 1 case of EGIST arising in the vulva and 2 cases of EGIST arising in the rectovaginal septum with review of related literature. Results Case 1 was a 59-years-old woman who was found to have a 4. 4 cm × 3 cm × 3 cm recurrent mass in the right vulva after 6 months of the first resection. Case 2 was a 58-years-old woman who presen-ted with a 7. 3 cm × 6. 1 cm × 4. 6 cm mass in the rectovaginal septum. Case 3 was a 41-year-old woman who presented with an 8. 6 cm × 7. 4 cm × 6. 7 cm mass in the rectovaginal septum. Histologically, the uniform spindle cells showed the interlacing fascicular, whirl-pool and palisade patterns with high cellular density. Mitotic figures were readily identified. Immunohistochemical evaluation revealed that the tumor cells exhibited strong and diffuse staining for CD117, CD34, NES, H-Caldesmon and DOG-1. Molecular analysis showed the gene mutation of c-Kit exon 11 in all 3 cases. Conclusion EGIST should be considered in the differential diagnosis of the mesenchymal tumors arising in the vulva and the rectovaginal septum. The immunohistochemical evaluation and molecular genetic tes-ting are crucial tools for the differential diagnosis and assessment of the prognosis and targeted therapy of EGIST.

Objective:To compare the quality of root-end preparation quantitatively between ultrasonic retrotips and traditional slow-speed handpiece.Methods:27 maxillary second bicuspid teeth with two canals and an isthmus were randomly assigned to 3 groups.Root-end preparations were made respectively using ultrasonic diamond tip Berutti and niti tip RE2,ultrasonic #40K file and slow-speed handpiece with No.2 round bur.Image processing and analysis system were used to measure the preoperation and postoperation parameters for further evaluating the difference between the two techniques.Results:The cutting volume of ultrasonic instruments was less than slow-speed handpiece(P

Objective To investigate the relationship between apolipoprotein E(Apo E) gene poly-morphism and mild cognitive impairment (MCI) in patients with type 2 diabetes mellitus (T2DM), and e-valuate the correlative risk factors. Method 40 cases of type 2 diabetes with MCI and 80 cases of type 2 diabetes without MCI were enrolled in this study. The polymorphism of the Apo E gene was detected by PCR-restriction fragment length polymorphism(PCR-RFLP). According to the clinical data such as course of disease, plasma glucose, plasma fat and body mass index (BMI), the independent risk factors of T2DM and MCI were analyzed by non-conditional logistic regression. Results The frequency of Apo E ε_4 allele in the group of type 2 diabetes with MCI was higher than that without MCI ( 25.0% vs 10. 0% ), and the difference had statistical significance( P < 0. 01 ). The indexes of the statistical significant difference be-twcen the two groups were age, course of disease, postprandial blood glucose ( P2BG), HBA1C, BMI,family history of T2DM, hypertension, diabetic retinopathy, diabetic peripheral neuropathy, Apo E gene. The independent risk factors included diabetic retinopathy ( OR = 3. 452, P < 0. 05 ), diabetic peripheral neuropathy( OR = 3. 252, P <0. 05), Ape E gene( OR = 2. 441, P < 0.01 ), HBA1C ( OR = 1. 372, P <0.05), P2BG(OR = 1. 194, P <0.05), age(OR = 1. 194, P <0.01) and course of disease(OR =1. 142, P <0. 05). Conclusion Apo E ε_4 allele has significant relationship with T2DM and MCI. The age, course of disease, control of plasma glucose, and microvascular complication of diabetes have relation-ship with the cognitive function.