OBJECTIVETo evaluate the effect of different silane couplers on bond strength and durability of two machinable glass ceramics to resin cement.

METHODSTwo machinable glass ceramics (A and B) were silanized by three silane couplers (A, B, C), and were bonded with a resin cement (G-CEM) to form micro-shear test specimens of six groups. The specimens of each group were subdivided into two subgroups, and their micro-shear bond strength was measured before and after 10000 thermal cycles. Bond strength data were analyzed by two-way ANOVA.

RESULTSBefore thermal cycles, the bond strength of ceramic A treated by silane coupler A was lower than that of ceramic B (P = 0.002). The bond strength of ceramic A treated by silane coupler C was significantly higher than that treated by silane coupler A and B (P = 0.014, P = 0.019). 10 000 thermal cycles obviously decreased the bond strength of all groups except the group of ceramic A treated by silane coupler B, and no significant difference was found between three silane coupler with either of two ceramic. However the bond strength of ceramic B treated by silane coupler B and C was significantly higher than that of ceramic A (P = 0.003, P = 0.027).

CONCLUSIONAs well as the types of silane coupler, the type of ceramic could affect their bond strength and durability to resin cement.

Ceramics ; Materials Testing ; Resin Cements ; Silanes

BACKGROUND: In recent years, clinical trials have considerably increased and relevant education programs to clinical trials have been developed and implemented since 2008 in Korea. To enhance the quality as well as global competitiveness of clinical trial professionals (CTPs), a certification program of the human resource is needed. Accordingly, in Korea the first and the second certification examinations were implemented in February and October 2012, respectively. In this paper, introduction of the certification program of the human resource is described, and results of the certification examinations and questionnaire survey are presented. METHODS: Data including the examination results and questionnaire survey was collected by cooperative officials in Korea National Enterprise for Clinical Trials. Applicants who were selected eligible for examination by the steering committee were asked to complete questionnaires provided with the test papers on the day of the certification examination. RESULTS: In the first certification examination, a total of 221 eligible participants completed the examination. 99.5 % of the participants responded the questionnaire survey. In the second examination, a total of 223 applicants participated. The examination consisted of 50 multiple-choice questions with cut-off score of 70 per cent score.176 & 194 CTPs passed the first & second examinations respectively. CONCLUSION: This paper that described the results of the two certification tests and questionnaire surveys might be helpful in establishment and activation of the certification program in the future. Quality improvement of CTPs and international competitiveness of clinical trial in Korea can be anticipated by the certification program.
Certification ; Cytidine Triphosphate ; Humans ; Korea ; Quality Improvement ; Surveys and Questionnaires ; Silanes

BACKGROUND: In recent years, clinical trials have considerably increased and relevant education programs to clinical trials have been developed and implemented since 2008 in Korea. To enhance the quality as well as global competitiveness of clinical trial professionals (CTPs), a certification program of the human resource is needed. Accordingly, in Korea the first and the second certification examinations were implemented in February and October 2012, respectively. In this paper, introduction of the certification program of the human resource is described, and results of the certification examinations and questionnaire survey are presented. METHODS: Data including the examination results and questionnaire survey was collected by cooperative officials in Korea National Enterprise for Clinical Trials. Applicants who were selected eligible for examination by the steering committee were asked to complete questionnaires provided with the test papers on the day of the certification examination. RESULTS: In the first certification examination, a total of 221 eligible participants completed the examination. 99.5 % of the participants responded the questionnaire survey. In the second examination, a total of 223 applicants participated. The examination consisted of 50 multiple-choice questions with cut-off score of 70 per cent score.176 & 194 CTPs passed the first & second examinations respectively. CONCLUSION: This paper that described the results of the two certification tests and questionnaire surveys might be helpful in establishment and activation of the certification program in the future. Quality improvement of CTPs and international competitiveness of clinical trial in Korea can be anticipated by the certification program.
Certification ; Cytidine Triphosphate ; Humans ; Korea ; Quality Improvement ; Surveys and Questionnaires ; Silanes

Authors studied how Claude Bernard, the first founder of experimental medicine, contributed significantly to establishment of modernism and influenced European modern culture. Authors first studied his views on modernity, comparing with Descartes and Magendie, and on the similarity between "Experimental medicine" and the European literature in the 19th century. Bernard was not exclusively against vitalism, but the dogmatic misuse of vitalism. His objective thinking could be a useful model for the authors, who considered science to be an origin of modernity in literature of naturalism. Especially, Emile Zola was strongly influenced by Bernard's "An introduction to the study of Experimental medicine" and published "Experimental novel," a manifesto of naturalism. Although Bernard's experimental methodology and determinism deeply influenced modern European culture, the relationship between his Experimental medicine and modernism have not been fully investigated yet. His experimental medicine also needs to be discussed from the ecological viewpoints. His anthropo-centrism was unique since he emphasized any human theory could not surpass the principle of nature. Conventional anthropo-centrism claims that human beings are superior enough to own and govern the nature. And Bernard's the necessary determinism contains the ecological principle that all life forms and inanimate objects are organically related and intertwined to each other, irrespectively of their usefulness for the human beings. Although there were some ethical debates related to his medical experiments on living bodies of animal, his strict principle to perform experiments only after animal or human body died was worth considering as an effort to sustain ecological viewpoints. He was also unique in terms of being realistic and candid about his situation which was limited by the 19th century's scientific and medical development. In conclusion, the significance of convergence of literature and medical science in Experimental medicine and the importance of Bernard's ecological viewpoints, need to be further studied in the field of medical history.
Animals ; Ecology ; Human Body ; Humans ; Photosensitizing Agents ; Silanes ; Thinking ; Vitalism

Accidents, Occupational ; Adult ; Blast Injuries ; Humans ; Male ; Middle Aged ; Silanes

OBJECTIVETo study the monomolecular coverage of the silane coupling agent gamma-methacryloxypropyltrimethoxysilane (gamma-MPS) on the barium glass filler surface.

METHODSKubelka-Munk (K-M) function values of the isolated OH-groups on the barium glass filler surface, which were based on the change of gamma-MPS concentrations, were measured using the quantitative analysis of the diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. When all of the isolated OH-groups on the filler surface disappeared (where the K-M function values was zero), the monomolecular coverage of the gamma-MPS molecules on the filler surface was indicated by the linear regression analysis.

RESULTSThe relationship tallied with negative linear correlation between the K-M function values of the isolated OH-groups on the barium glass surface and the concentrations of gamma-MPS. Each gamma-MPS molecule occupied 0.21 nm(2) when the monomolecular coverage was formed on the barium glass surface.

CONCLUSIONSThe result of this study indicated the optimal amount of silane coupling agent on silanated barium glass filler during the production of resin composite.

Barium Compounds ; chemistry ; Composite Resins ; chemistry ; Dental Materials ; chemistry ; Methacrylates ; chemistry ; Silanes ; chemistry ; Silicon Dioxide ; chemistry

A new, simple and sensitive method was developed for the determination of silicon tetrahydride in the air of workplace in this study. The alkaline resin-based spherical activated carbon was used to collect sample of silicon tetrahydride at workplace. Silicon tetrahydride was then desorbed from active carbon in 100°C hot water. After reacting with ammonium molybdate, oxalic acid and 1,2,4-trichlorobenzene alpha-naphthol amino sulfonic acid under acid condition, silicon tetrahydride was transformed into silicon molybdenum blue. The absorbance of silicon molybdenum blue was quantitatively measured at the wavelength of 680 nm. The results showed that the average sampling efficiency and desorption efficiency were 97.53% and 94.94%, respectively by this method. Detection limits were 0.054 μg/mL for the spectrophotometric method and 0.14 mg/m(3) for the determination of silicon tetrahydride in the air of workplace (sampling volume was 7.5 L). The conversion rate of silicon tetrahydride gradually decreased when storage time of samples was extended. The descent rate of sample was less than 10% when the sample was sealed for 7 days in the room temperature. It was concluded that this spectrophotometric method can be successfully used to determine silicon tetrahydride in the worksites.
Air Pollutants, Occupational ; analysis ; Humans ; Limit of Detection ; Reproducibility of Results ; Silanes ; analysis ; Spectrophotometry ; methods ; Workplace

OBJECTIVETo study the influence of three different metal alloy surfaces treated with primer methacryloxy propyl trimethoxyl silane (gamma-MPS) coupling agent on the bond strength of Filtek Z350 resin.

METHODSTotal 36 specimens of nickel-chromium(Ni-Cr) alloy, pure titanium(Ti) and aurum-palladium(Au-Pd) alloy, each of 12 pieces produced by lost wax casting method, were divided into 6 groups. After treated with gamma-MPS on the bonding surface, experimental group samples were adhered to Filtek Z350 resin, then compared with the surface without gamma-MPS treatment. The tensile and shear strength of each group tested and the fracture sections were observed with scanning electron microscope (SEM).

RESULTSComparing the Ni-Cr alloy and pure Ti experimental group with them in control group, the shearing strength of the experimental group was higher, and the differences were significant (P < 0.001). The shearing strength of the experimental group and control group of Au-Pd alloy were not significant (P > 0.05). Comparing the experimental groups, the shearing strength of pure Ti was higher than Ni-Cr alloy, both were higher than Au-Pd alloy (P < 0.01). These entire specimens were adhesive fracture. Comparing with the control group, Ni-Cr alloy and pure Ti experimental group showed more resin juts in the fracture surface, while the Au-Pd alloy in experimental group showed less resin juts.

CONCLUSIONgamma-MPS can enhance the adhesion between metal and resin, but it is also related to the metal composition. gamma-MPS can significantly increase the bond strength of resin and Ti or Ni-Cr alloy, but not the case of Au-Pd alloy and resin.

Chromium Alloys ; Composite Resins ; Dental Alloys ; Dental Bonding ; Materials Testing ; Shear Strength ; Silanes ; Surface Properties ; Titanium

This paper describes measurement of vapor-liquid equilibrium (VLE) data of methyldichlorosilane-methyltrichlorosilane-dimethyldichlorosilane system and that of the three binary systems at 101.325 kPa with a new pump-ebulliometer. The equilibrium composition of the vapor phase was calculated from pTx by indirect method. The model parameters of the liquid activity coefficient of the Wilson, NRTL, Margules and van Laar equations was corrected by the least square method. The ternary system VLE data were predicted by the Wilson equation, with the calculated boiling points showing good agreement with the experimental data.
Computer Simulation ; Gases ; chemistry ; Models, Chemical ; Phase Transition ; Pressure ; Silanes ; chemistry ; Volatilization

OBJECTIVETo investigate the influence of three primers on the shear bond strength between cast titanium (Ti) and composite resin.

METHODSThe disks (n = 40) were cast by commercially pure (CP) Ti, which diameter were 8 mm and thick were 3 mm. The titanium surfaces were polished with silicon carbide sand papers under running water and then treated by sandblasting and acid (4%HF) etching. They were divided into four groups: control group (group A), treated with KH-570 (group B), treated with Alloy Primer (group C), treated with Metal photo primer (group D). After treatment, the specimens were evaluated for their shear bond strengths by universal testing machine. The values were statistically analyzed. The fractured surfaces were observed by scanning electron microscope (SEM).

RESULTSThe shear bond strengths of group A, B, C, D were (9.773 +/- 0.67), (11.463 +/- 0.82), (14.224 +/- 0.75), (13.157 +/- 0.73) MPa. There were significant differences in bond strength between A and B, C, D (P < 0.01). B and C, D had significant differences (P < 0.01). C and D had no significant differences (P>0.05).

CONCLUSIONKH-570, Alloy Primer, Metal photo primer significantly improve the bond strength of ceramage composite resin to cast titanium. KH-570 group bonding strength is lower than the the Alloy Primer group and Metal photo primer group.

Composite Resins ; Dental Bonding ; Materials Testing ; Methacrylates ; Shear Strength ; Silanes ; Silicates ; Thiones ; Titanium