The influence of hemostatic agent contamination on bond strengths on dentin bonding agents / 대한치과보철학회지

PURPOSE: This study examined the recovery of the dentin-resin bonding strength, and the difference in the bonding strength after applying pH hemostatic agents at various pH. MATERIALS AND METHODS: Bosmin, Hemodent, Astregedent, and Visine were used as the hemostatic agents in this study. The Bosmin, Hemodent, and Astrigedent hemostatic agents are acidic, and the Visine hemostatic agent is neutral and is used as a decongestant. Ninety human molar teeth were used as the specimen. The teeth were sectioned using a diamond wheel until the dentin was exposed and wet ground by silica paper. The specimens were divided into two groups according to the hemostatic agent used. The specimens were then subdivided into 9 groups according to the application of re etching (R group) or rinsing only (N group). A commonly used resin bonding procedure was used in the control group. The resin bonding procedure was managed dentin using celluloid capsule. In addition, the shear bond strength was measured using an Instron. RESULTS: In general, samples with the applied hemostatic agent, with the exception of Visine, had a slightly weak bond that was similar to the control group. In addition, the rinsing only (N) group had slightly weak bond that was similar to the re etching (R) group. CONCLUSION: The application of a hemostatic agent on the dentin surface does not affect the shear bond strength after application for a short time. In addition, rinsing only can recover the shear bond strength making other management procedures redundant, particularly re etching.

Comparison of Gas Exchange Indices after Open Heart Surgery / 대한마취과학회지

BACKGROUND: The objectives of the study were to determine how gas exchanges indices including alveolar-arterial oxygen tension difference(A-aDO2), PaO2/PAO2, PaO2/FIO2 and pulmonary shunt ratio (QS/QT) were changed after open heart surgery according to the change of inspired fraction of oxygen(FIO2) and to identify the reliable parameters for postoperative respiratory care in the intensive care unit. METHODS: Blood gases were measured from radial and pulmonary arterial blood for arterial and mixed venous blood in 15 patients, with a mean age of 45.1 yr, after open heart surgery, in mechanically ventilated states with 1.0, 0.6 and 0.4 of FIO2 with normocarbia maintained (PaCO2 30~40 mmHg). Above mentioned gas exchange indices were calculated and compared. RESULTS: After decreasing the FIO2 from 1.0 to 0.6 and 0.4 in order, the major changes were significant decrease in pulmonary shunt ratio : 24+/-3%, 17+/-3% and 11+/-3% at FIO2 1.0, 0.6 and 0.4, respectively and A-aDO2 : 347+/-34 mmHg, 184+/-16 mmHg and 94+/-11 mmHg at FIO2 1.0, 0.6 and 0.4 respectively, while PaO2/PAO2 showed the only significant increase at FIO2 0.4 compared with those at FIO2 1.0 and PaO2/FIO2 was unchanged. CONCLUSIONS: In cases of open heart surgical patient with cardiovascular stability, pulmonary shunt ratio and A-aDO2 appear to be more sensitive on gas exchange, but the oxygen tension indices such as PaO2/PAO2 as well as PaO2/FIO2 might be suggested as possible alternatives for the shunt measurement.