Objective: To observe the effects of acid etching times on nano-leakage and microtensile bond strength(?TBS) of the 4 total-etching adhesives-dentin bond.Methods: Superficial occlusal dentin surfaces of 80 molars were prepared with 600-grit SiC paper under running water.4 adhesives were applied to dentin surfaces under different etching time.The bonded teeth were sectioned occluso-gingivally into 1.0 mm?1.0 mm?4.0 mm serial slabs which were prepared for TEM and ?TBS tests.Results: Under 15 s etching time for 4 adhesives,the highest ?TBS(OB(25.36?4.18) MPa,SB(24.25?3.97) MPa,OS(28.65?4.93) MPa,PB(27.12?4.13) MPa) were achieved,and the amount of nanoleakage was positively correlated with the length of etching time.Conclusion: Etching for a reasonable time demineralizes the dentin surface to a moderate depth,resulting in higher ?TBS and lower nanoleakage.

Objective: To study the effect of cementation materials on the fracture resistance of metal free premolar Artglass crown. Methods: Thirty extracted human maxillary premolars were regularly prepared for cementation. Artglass crowns were cemented onto the teeth with zinc phosphate cement (ZnP), glass ionomer cement(GIC)or a resinous cement in combination with a dentinal bonding agent. Each of the cementation material was applied in 10 premolars. Artificial crowns were vertically loaded until the Artglass crowns compressed to failure. Significant differences of fracture loads between experimental groups were assessed by paired t test. Results: The fracture load(N) of ZnP, GIC and resinous cement were 1 743.1 ?383.4, 1 682.4?613.7 and 2 226.9?270.1 respectively( P

Objective:To test the effects of different preparation methods on the shear bond strength between porcelain veneers and the brackets.Methods:48 metal-porcelain veneers were randomly and evenly divided into two groups. The veneers in group 1 were grinded with stone, while others were intact. The veneers were bonded by acid etching,silicone coupler and acid etching combined with silicone coupler respectively.After bonding and 500 thermo cycle treatment, all veneers were submitted to shear bond strength test and the incidence of porcelain fracture was recorded.Results:The shear bond strength of the grinded samples was higher than that of the intact(P

Objective To explore discussion medical treatment in massive hemoptysis emergency surgical treatment.Methods Hemorrhage parts,timing of surgery,pneumonectomy scope in 24 cases of massive hemoptysis were analyzed.Results 24 cases of massive hemoptysis emergency surgical treatment were successful,no death and complication rate was 8.3% (2/24).Conclusion For medical treatment ineffective massive hemoptysis determine the location of the bleeding,actively carry out preoperative preparation, choosing the best opportunity emergency resection of lung disease,can be effective in reducing mortality.

Objectives: To evaluate the effect of thickness and opaque resin on the light transmittance of Artglass. Methods: Samples of Artglass prepared in the thickness(mm) of 0.50,0.75,1.00,1.25,1.50,1.75 and 2.00 with or without opaque resin respectively.The light transmittance of the specimens was measured. The color values of the specimens on the CIE L*a*b* color system were determined by a digital chroma meter. Results: The light transmittance of Artglass decreased logarithmically with the increase of the thickness (R2=0.9834 in the group of samples without opaque and R2=0.9390 in those with opaque). The light transmittance of Artglass with opaque resin was lower than that without opaque resin. Conclusion: Thickness and opaque resin have significant effect on the light transmittance of Artglass.

0.05), the FADRHPC could save a great amount of time and worked automatically. Conclusion: The FADRHPC can simplify manipulation processes and make satisfied dentures.

Objective: To compare the fracture resistance of pulpless teeth restored with three types of post core.Methods: A total of 21 recently extracted sound upper incisors were randomly distributed into 3 groups. In group A the teeth were restored with prefabricated glass fiber post and composite core; in group B with custom cast titanium alloy post and core; and in group C with Ni Cr alloy dowel core. The size and shape of posts were identical in the 3 groups. All teeth were fully covered with Ni Cr alloy cast crown. Fracture resistance was measured by applying a point force at 130 degrees to the long axis of the teeth. Results: Mean fracture threshold was (276.6?15.1)N in group A, (394.7?29.1)N in group B and (373.4? 53.8 )N in group C. In group B and C, however, fracture always affected the tooth itself,whereas in group A,the core always failed first. Conclusion: Fiber reinforced composite(FRC) post may meet the clinical need, FRC post combined with composite core may prevent tooth root from fracture.

Objetives: To evaluate the microtensile bond strengths o f four dentin adhesives (Single Bond, Bond-1, Prime&Bond NT and One-Step) i n vivo.Methods: Before extraction the superficial occlu sal dentin of 19 molars (because of severe periodontitis) in 17 volunteers was exposed by diamond bur of a high-speed hand-piece copious air-water spray under local anesthesia, the crown was bonded with one of the above adhesives a ccording to the manufacturers' instructions. The teeth were then extracted and kept in normal saline for 24 h under 37 ℃,sectioned to obtain two or three bar -shaped specimens, which were then shaped to an hour-glass form. The specimens were stressed until rupture of the bond. The mean bond strength of the adhesive s was measured and compared using student test. Rusults: M ean microtensile bond strength (MPa) of Single Bond,Bond-1,One-Step and Prime & Bond NT to the tooth surface was 26.18?3.67,30.08?3.15,29.91?3.51,29.70?3 .03 respectively (P

Objective To summarize the progresses made domestically and abroad and the developmental tendency of stomatology,and to propose the orientation of development in stomatology in China. Methods The latest progresses and developmental tendency in the field of stomatology were achieved by investigating related references,reviews,research reports and treatises published in recent 10 years. Results In recent years,the increasing integration of stomatology,comprehensive medicine,biomedical engineering,and tissue engineering facilitated the development of stomatology towards digitization,minimal invasion,functionalization and customization,which has made great achievements in basic researches and clinical techniques of stomatology in the armed forces. Conclusions It is the key period of the Twelfth Five-Year Plan for the development of the stomatology in the armed forces. Servicing the basic level of the troop,promoting dominant subjects,improving weak components of the discipline,and comprehensively promoting the internationalization should be insisted in driving innovations of stomatology in the armed forces.

Objective:To measure the effect of disinfection on dimension stability of four high polymer impression materials which were separately immersed in 20 ml/L glutaraldehyde solution.Methods:Fifteen plaster replication models of four high polymer impression materials(Impregum Penta polyether, Express-Putty silicone, Silagum-Putty silicone, GC EXAFINE silicone) were made on the same metal master cast respectively. Vertical and horizontal dimensions between landmarks on the masters and plaster casts were measured with an optical microscope,one-way ANOVA was used to compare the measurements among the materials.Results:The difference between the masters and Casts in horizontal distances measured on Express-Putty silicone impression material produced models was longer than those on other high polymer impression materials produced ones after disinfection for 20 minutes and beyond clinical requirement. Compared with metal master cast, the difference became significant when these four silicone impression materials were disinfected for 40 minutes. Conclusion: Among the four kinds of impression materials, the Express-Putty silicone material is relatively the most accurate one after disinfection for 20 minutes.