Objective; To evaluate the reliability and reasonability of maxillofacial skin color match using the digital camera. Methods; The stability of the experimental light source was evaluated before establishing the color measurement. 122 volunteers aged from 22 to 32 years were recorded by a Canon EOS 20D digital camera in studio environment when the light source was stable. Photographs were taken under a set exposure parameters(f/4.5,1/25 s,custom white balance,ISO 800) and saved as JPEG format. The CIE L~* a~* b~* color values were obtained from the digital images using Adobe Photoshop7.0 after color correction. All data were analyzed using SPSS 10. 0. Results;The experimental light source was stable in 21 to 70 minutes. It was suitable for color measurement during this period. The color parameters of all tested maxillofacial skin were:L~*49～66,a~*7 - 18,b~*5 -22. Conclusion;The assessment of maxillofacial skin color depend on method of measurement and instrument. The method of maxillofacial skin color matching by digital camera seems reliable.

Objective: To evaluate the effect of roughness on adhesive properties of polymethyl methacrylate and SY-1 silicone elastomer.Methods:5 specimens of polymethyl methacrylate were polished by sand paper of different standards and the roughness of polymethyl methacrylate surfaces were measured by roughmeter. The tension strength between polymethyl methacrylate with different degrees of roughness and SY-1 silicone elastomer were tested according to national standards. Results: After the surfaces of polymethyl methacrylate were respectively polished by sand paper of the standard 160,320 and 800, the sufrace roughness decreased, but the tension strength between polymethy1 and SY-1 silicone elastomer was increased(P

0.05).The elongation at break of SY-1 was stronger than that of MDX4-4210 (P

Objective To explore the clinical application of reconstructing silicone elastomer nose prosthesis by means of selected laser sintering and wax powder PCPI. Methods Laser scanning was used to get the 3-D data of a nose model. Surfacere 10.0 etc softwares was used to reconstruct the nose by mirroring the digitalized model of absent nose. Selective laser sintering and wax powder was chosen to fabricate a wax nose model and the nose prosthesis made by silicone clastomer. Results Perfect silicone clastomer nose prosthesis was made for 2 patients. Conclusion This study suggests that the wax nose model and the new wax powder can meet the requirement of clinical expectation for maxillofacial prosthesis.

Objective:Through monitoring the pH of the growth medium,to evaluate the growth and/or acid production ability of Candida albicans on silicon elastomer incorporated with two different antifungal agents.Methods:Antifungal agents(AntimTM-AM and Conval pag-40)were added at concentrations from 0% to 2%,and antibacterial effect of the material in saliva and serum groups were examined.The third group added nothing was served as the control.Results:Each group with 2% antifungal agents showed great inhibitory effects on the acid production and /or the growth of C.albicans.These inhibitory effects consisted of a delay in the onset of rapid pH decline,decreased with the rate of pH change and increased in minimum pH.As a result,Conval pag-40 showed a significantly greater antimicrobial effect than AntimTM-AM.Conclusion:Silicone elastomer material incorporated with antifungal agents have strong antibacterial ability and can satisfy the requirements of clinical application.

Objective:To evaluate a new wax formed by laser sintering technology(SW-1)for dental use.Methods:The melting point,hardness and viscosity of SW-1,normal dental modeling wax and LongYuan's wax formed by laser sintering were tested and compared.Linear shrinkage,plastic deformation and toughness of SW-1 were estimated by national standards.Results:There were no significant differences between SW-1and the normal dental modeling wax in the properties of melting point 〔(61.1?1.63)℃,(61.7?1.96)℃〕and hardness 〔(75.2?0.62)HA,(74.0?0.54)HA〕;but when compared with melting point(78.3?1.07)℃and hardness(94.0?0.38)HA of LongYuan's wax formed by laser Sintering,those of SW-1 were significantly different.Viscosity of SW-1(2 016?136.9)MPa?s showed significant difference when compared with that of normal dental modeling wax(9.06?0.258)MPa?s and LongYuan's wax formed by laser Sintering(2 876?81.7)MPa?s.Linear shrinkage of SW-1(0.2%)met the national standards,while plastic deformation(10%,43 ℃)and toughness(broken when bent,20 ℃)of SW-1 did not meet such standards.Conclusion:SW-1 may be the proper laser sintering material for dental use,and has a good prospect in future.

Objective:To evaluate the effects of primers on the bonding of an silicone elastomer to acrylic resin.Methods:Acrylic resin specimens were divided into eight groups.Six new primers and Cosmesil G611 primer were applied to the acrylic resin surfaces respectively.Untreated group was used as control.The shear bond strengths between silicone elastomer and acrylic resin were determined.D primer were measured by Forier transform infrared spectroscopy,and the bands were analyzed using spectrum method.Results:The experiment group with different concentration of ?-MPS showed different shear bond strengths between silicone elastomer and acrylic resin.Type D primer showed 2.20 MPa shear bond strength,which was significantly higher than that of other groups.While 1.44 MPa for Cosmesil G611 primer was found,there was no bond strength for untreated group.Conclusion:The concentration of ?-MPS is relative to the shear bond strength and type D primer can give the highest shear bond strength.

Objective To test the performance of the field digital oral medical vehicles(two chairs) developed by School of Stomatology,the Fourth Military Medical University.Methods The field digital oral medical vehicle was developed by using dental health care system,diagnostic imaging systems,oral endoscopic systems,infection control systems,digital management system,the sewage treatment system,temperature conditioning systems,power generation systems,automotive GPS positioning system and other systems.Results The vehicle was characteristized by reliable performance,high degree of functional serialization,complete medical facilities and good operability of the internal layout.Conclusion Its functions fully meet the requirements in field oral disease prevention and control as well as first aid.

砄bjective:To compare the adherent ability of Candida albicans on the surface of two kinds of silicone elastomer used as prosthodontic materials and to study the factors affecting the adherence.Methods: Candida albicans were cultured on the surface of SY 1 and MDXA 4210 with or without saliva acquired pellicle for 10 min, then the number of the bacteria was counted.Results:With or without saliva acquired pellicle,the number (1?10 3/mm 2) of C.albicans on SY 1 was 24.5?0.88 and 2.0?0.47 respectively( P 0.05 ).Conclusion:There is little difference between the adherent ability of C.albicans on the two kind of silicone elastomer.Saliva acquired pellicle can decrease the adherence.

Objective: To develop a computer-aided three-dimensional design software and laser scanning technique for the restoration of unilateral orbital defect. Method: By laser scanning apparatus plaster face model and the acquired primitive face point data were scanned; with the three-dimensional design software the point data were reconstructed to one smooth face surface image and the data of the defect of the orbital tissue were obtained from the normal contralateral tissue data by software. Results: The face-model data obtained by laser scanning apparatus was distinct and precise; the Digisurf retrograde engineer software succeeded to fulfill the computer-aided design for restoration of unilateral orbital defect. Conclusion: The laser scanning technique and three-dimensional design software can be used in the computer-aided design of the unilateral orbital defect restoration.