0.01). There was a significant difference in TIMP-1,-2 expressions between saccule injury group and control group (P

Objective: To measure the convergence angles of teeth in different teeth positions and different denture designs.Methods:Mesio-distal widths and labio-lingual widths were measured on 226 teeth according to three points in a line on three surfaces (gingival, middle and incise) of each tooth.The distance between every point and the counterpart point in the adjacent surface was measured.Then convergence angles were calculated. Results:The means of the angles were 4.13°±0.77°,4.14°±0.76°, 4.46°±0.95°, 4.76°±0.84° on the first and second premolar, the first and second molar,respectively . There were significant differences between the premolars and molars(P<0.05).On the dentures with the designs of monocrown, triunit-bridge and long bridge the means of the angles were 3.78°±0.74°,4.69°±0.75° and 5.08°±0.85° respectively,the angle on the denture with the design of monocrown was smaller than that of bridge (P<0.05).Conclusion:The convergence angles are different according to different teeth positions and different denture designs, so they should be adjusted according to the clinical requirements.

s〕 Objective:To investigate the influence of repeated firings on the color of porcelain fused to metal crown(PFM) . Methods: 5 PFM samples were prepared and fired for 9 times.The color of the samples was measured following firing with CIE1976 L*a*b* color system . The color difference ?E ab *,hue angle h ab * and chroma C ab * were calculated according to the following calculations:?E ab * ={(?L*) 2 +(?a*) 2 +(?b*) 2} 1/2 , C ab * ={(a*) 2+(b*) 2} 1/2 , h ab *=tg 1 b*/ a*, L* presented brightness. Results: After repeated firing, L* value of PFM , C ab * and L* value of dentin layer and h ab * value of opaque layer increased. Conclusion: The color of PFM after repeated firing may become brighter. The color change is resulted from the increase of L* and C ab * of dentin layer.

Objective: To study the influence of repeated firings on the PFM bond strength. Methods: 25 specimens of PFM in the diameter of 13.0 mm and thickness of (1.0?0.02) mm were prepared and fired at 920 ℃ for 1, 3, 5, 7 or 9 times(5 samples for each time). The remained porcelain rate(RPR) was measured by Mackert method and used to evaluate the bond strength.Results: After 3 firings, the RPR of PFM decreased obviously, and additional firings had no obvious effect on the RPR. Conclusion: 3 times firing or more may decrease the bond strength of PFM.

0.05,group 1 or group 2 vs group 3 P

To investigate the effects of different surface conditioning methods on the shear bonding strength of glass-infiltrated ceramic to dentine, 24 glass-infiltrated ceramic testing-pieces were divided into four groups randomly. Among them 3 groups were treated with A(sandblasting+silance), B(etching+silace) or C(silance), separately, while group D was set as the control. Bonding the ceramic pieces to dentine with Super-Bond and the shear bonding strengths was measured. The results showed that the shear bonding strength of group D was lower than that of group A, B and C (P0.05). It is suggested that surface conditioning using combined sandblasting with silance can remarkbly improve the shear bonding strength of glass-infiltrated ceramic to dentine.

Objective To establish Phage Amplified Biologically Assay (PhaB) detecting isoniazid(INH) resistance rapidly and evaluate PhaB assay for drug susceptibility testing of isoniazid(INH) in clinical isolates of Mycobacterium tuberculosis(MTB). Methods Detecting the INH resistance of 167 clinical isolates of MTB by PhaB assay,comparing the results of PhaB with that of Bactec-960 system and analyzing the sensitivity, specificity and accuracy of PhaB assay. Results When the mixture of 0.2 ?g /ml INH and MTB was incubated in 37℃ for 48 h, the accurate results were obtained rapidly by calculate the reduce of plaque of PhaB assay. If the results of Bactec-960 system is the golden standard, the sensitivity, specificity, PPV, NPV and accuracy of PhaB assay was 96.4%, 96.4%, 93.1%, 98.2% and 96.4% respectively. Conclusions The PhaB assay with highly sensitivity specificity are highly consistent with Bactec-960 system. Not only it takes only three days to detect drug susceptibility of INH in clinical isolates of MTB but also it is easily to operate. We believe that this low-cost assay may be a good rapid screening of INH resistance in MTB isolates.

Objective Evaluating possibility of phage amplified biologically(PhaB) assay in detecting susceptibility of Mycobacterium tuberculosis(MTB) to four first-anti-tuberculosis-drugs on the same time and of 139 clinical isolates to streptomycin(S), isoniazid(H), rifampin(R) and ethambatal(E) at the same time, comparing with the results of Bactec-960 and determining the minimal inhibitory concentrations(MIC) of isolates which results were not consistent. Results Concordance rates of the susceptibility to S, H, R and E in 139 clinical isolates detected by PhaB and Bactec-960 are 97.1%, 99.3%, 95.7% and 95.0% respectively. If the results of Bactec-960 system is the golden standard, the sensitivity, specificity, positive and negative predictive value (PPV and NPV) as well as accuracy of susceptibility test to S detected by PhaB assay was 90.0%, 99.1%, 96.4%, 98.2% and 97.1% respectively, to H 97.9%, 98.9%, 97.9%, 98.9% and 95.0% , to R 86.2%, 97.3%, 89.3%, 96.4% and 95.0%, to E 81.0%, 97.5%, 85.0%, 96.6% and 95.0%. There are 19 inconsistent results of 13 isolates in comparing PhaB with Bactec-960. 18 results of 12 isolates by MIC are identical with the results of PhaB assay. 1 result of 1 isolate is identical with Bactec-960. Conclusions[KG1]The results of susceptibility to S, H, R and E detected by PhaB were highly concordance rate with the results of Bactec-960. PhaB assay can be used for rapid screening of susceptibility test for MTB.

Objective To assess the sanitary quality of finished water produced by seawater desalination plant.Methods Using reverse osmosis for seawater desalination,the microbiological indexes,the levels of chloride and the pH values of finished water after seawater desalination were determined and then were assessed based on the National Method for Determination of Drinking Water(GB 5750-1985).Results After seawater desalination,the level of fluoride in finished water was 426 mg/L,the total count of bacteria of 3 finished water samples among 9 samples exceeded the standedard(350,300,4016/L),the pH valuer were qualified on the whole,except one lower value of 5.74 and a higher value of 8.94.Conclusicn After the treatment by seawater desalination system,the level of residual chloride in finished water was higher which approached the related highest limit ruled by National Sanitary Standard for Drinking Water,the microbiological indexes and pH values of finished water were unstable.