No abstract available.
Reference Values*

No abstract available.
Reference Values*

No abstract available.
Reference Values*

No abstract available.
Reference Values*

No abstract available.
Reference Values*

The quality correction in the air kerma dosimetry for Ir-192 using farmer type ionization chambers calibrated by Co-60 quality is required. In this study we determined quality factor (kappa u) of two ionization chambers of PTW-N30001 and N23333 for Ir-192 source using dosimetric method. The quality factors for energy spectrum of microSelectron were determined as kappa u=1.016 and 1.017 for PTW-N30001 and N23333 ionization chambers respectively. We applied quality factors in air kerma dosimetry for microSelectron source and compared with reference values. As a results we found that the differences between reference air kerma rate and measured it with and without quality correction were about -0.5% and -2.0% respectively.
Gamma Rays ; Reference Values

No abstract available.
Blood Pressure* ; Reference Values*

PURPOSE: This study was to evaluate the accuracy of how to use the Mechanical Torque-Limiting Devices. MATERIALS AND METHODS: Three different implant manufacturers (Dentium, Osstem, Shinhung) were prepared for each two implant torque controllers. Divided into two groups depending on the method used for removal torque was measured. Repeated measures of ANOVA test (alpha=.05) was used as statistics to evaluate the effect of repeated loading number on the removal torque. Independent t-test was used to evaluate the difference in removal torque of two groups. RESULTS: The removal torque significantly decreased as the number of loading repetition increased (P<.05). There was significant difference between two groups. CONCLUSION: Loosen the handle part of the implant torque controllers spring resilience to recover one group compared to the group that did not, showed a little more closed to the reference value.
Reference Values ; Torque*

PURPOSE: To compare the dimensional accuracy of three impression techniques- a separating foil impression, a custom tray impression, and a stock tray impression. MATERIALS AND METHODS: A machined mandibular complete-arch metal model with special modifications served as a master cast. Three different impression techniques (n = 6 in each group) were performed with addition-cured silicon materials: i) putty-wash technique with a prefabricated metal tray (MET) using putty and regular body, ii) single-phase impression with custom tray (CUS) using regular body material, and iii) two-stage technique with stock metal tray (SEP) using putty with a separating foil and regular body material. All impressions were poured with epoxy resin. Six different distances (four intra-abutment and two inter-abutment distances) were gauged on the metal master model and on the casts with a microscope in combination with calibrated measuring software. The differences of the evaluated distances between the reference and the three test groups were calculated and expressed as mean (± SD). Additionally, the 95% confidence intervals were calculated and significant differences between the experimental groups were assumed when confidence intervals did not overlap. RESULTS: Dimensional changes compared to reference values varied between -74.01 and 32.57 µm (MET), -78.86 and 30.84 (CUS), and between -92.20 and 30.98 (SEP). For the intra-abutment distances, no significant differences among the experimental groups were detected. CUS showed a significantly higher dimensional accuracy for the inter-abutment distances with -0.02 and -0.08 percentage deviation compared to MET and SEP. CONCLUSION: The separation foil technique is a simple alternative to the custom tray technique for single tooth restorations, while limitations may exist for extended restorations with multiple abutment teeth.
Reference Values ; Silicon ; Tooth

In order to observe the influence of visual display terminal (VDT) work on accommodative function, we measured accommodative power, accommodative constriction time and accommodative response / accommodative stimulus ratio (Ar / As) by infrared optometer on 15 normal subjects who were not exposed to VDT work before. VDT task was programed to search a specified Korean alphabet letter among randomized letters for 90 minutes. After VDT task, accommodative constriction time was prolonged, near point extended and accommodative power decreased in all subjects (p<0.05, by paired t-test). After resting for 30 minutes, constriction time, near point and accommodative power had a tendency to return to the previous normal value. Accommodative response / accommodative stimulus ratio (Ar / As) was decreased according to the duration of VDT work but no statistical difference was found between before and after VDT work. From this study, it is suggested that the function of accommodation seems to be affected by VDT work.
Constriction ; Reference Values