• Restorative Dentistry and Endodontics
• /
• v.49 no.1
• /
• pp.10.1-10.8
• /
• 2024

Objectives: This study aimed to evaluate the content, quality and demographics of YouTube videos about rubber dam as an information source for clinicians and dental students. Materials and Methods: "Rubber dam," "rubber dam application," "dental isolation," "rubber dam isolation," and "dental dam" were determined as keywords for the detection of YouTube videos related to rubber dam. Seventy 3 videos were evaluated and a total of 34 videos met the inclusion criteria. All selected videos were evaluated according to 8 parameters. The videos were scored 1 if the videos contained information about the selected parameter, but if the videos did not contain enough information, they were scored 0. The data were statistically analyzed with the analysis of variance and post hoc Tukey test (p < 0.05). Results: We found that 41% of the videos have poor, 47% have moderate, and 12% have good information. There is a statistically significant difference in time between poor and good information content (p < 0.05). There is a statistically significant difference between the poor and good information in the video information and quality index 1. Conclusions: Rubber dam-related videos available on YouTube are generally moderately informed and insufficient. YouTube is currently not sufficient as a source of information for patients and clinicians at the moment. The YouTube platform should be developed and enriched with quality information on current and dental issues.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.29A no.3
• /
• pp.72-78
• /
• 1992

The Silicon vertical Hall devices are fabricated using standard bipolar process and characterized in terms of the Hall voltage, sensitivities, and offset voltage. The Hall voltage and sensitivity of the devices showed good linearity with respect to the magnetic flux density and reverse supply voltage Vr. The sensitivity of device with P$^{+}$ isolation dam has been increased up to 1.2 times compared to that of device without the dam. With the condition of V$_{r}$=-5.0[V], B=0.4[T] and I$_{sup}$=1.0[mA], the Hall voltage and sensitivity of the device with P$^{+}$ isolation dam were about 29[mV] and 74[V/AT], respectively. These vertical Hall devices can be used as the adjustable magnetic fields sensor.

• Journal of Sensor Science and Technology
• /
• v.23 no.6
• /
• pp.392-396
• /
• 2014

The 2-dimensional silicon vertical Hall devices, which are sensitive to X,Y components of the magnetic field parallel to the surface of the chip, are fabricated using a modified bipolar process. It consists of the thin p-layer at Si-$SiO_2$ interface and n-epi layer to improve the sensitivity and influence of interface effect. Experimental samples are a sensor type K with and type J without $p^+$ isolation dam adjacent to the center current electrode. The results for both type show a more high sensitivity than the former's 2-dimensional vertical Hall devices and a good linearity. The measured non-linearity is about 0.8%. The sensitivity of type J and type K are about 66 V/AT and 200 V/AT, respectively. This sensor's behavior can be explained by the similar J-FET model.

• Journal of Sensor Science and Technology
• /
• v.20 no.4
• /
• pp.260-265
• /
• 2011

The silicon vertical hall devices are fabricated using a modified bipolar process. It consists of the thin p-layer at Si-$SiO_2$, interface and n-epi layer without $n^+$buried layer to improve the sensitivity and influence of interface effects. Experimental samples are a sensor type I with and type H without p+isolation dam adjacent to the center current electrode. The experimental results for both type show a more high current-related sensitivity than the former's vertical hall devices. The sensitivity of type H and type I are about 150 V/AT and 340 V/AT, respectively. This sensor's behavior can be explained by the similar J-FET model.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.10
• /
• pp.1890-1896
• /
• 2008

In this paper, the Si vertical Hall devices ale fabricated by using standard bipolar process and investigated in terms of the opeating and noise properties. The sensitivity of device with P+ isolation dam(type B) has been increased up to about 1.2 times compared to that device without the dam also noise has been increased. With the condition of f=I[KHz], band-width 1[Hz], the resolution of magnetic-field detection were about $0.97[{\mu}T]$/ type B and $1.25[{\mu}T]$/ type A, respectively, thus we must consider correlation the low noise or good resolution and high sensitivity in the situation for device geometry design or even for the materials.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.3
• /
• pp.415-422
• /
• 2003

Currently, 'National program of dental sealant' has begun in Korea, but various isolation techniques and preparation is performing. The aim of the present study was to compare pit and fissure sealant retention rates between different operators using two different isolation techniques. Additionally, the failed surface was examined. One examiner performed the examination after one year of the initial operation. The population consisted of 119 children(mean age $8.59{\pm}0.772$) of which the total sealed number was 279 permanent first molars. Pediatric dentists sealed 131 molars using the rubber dam isolation technique (Group 1), general practitioners sealed 80 molars using the rubber dam isolation technique (Group 2), and dental hygienists sealed 69 molars using the cotton roll isolation (Group 3). The results were as follows ; 1. The complete retention rate between Group 1 (90.8%) and 2 (85.0%) showed no significant statistical difference (P>0.05). However, there were significant statistical different retention rates between Group 1 and Group 3(64.7%) and between Group 2 and Group 3 (p<0.05). 2. In comparing retention rates between maxilla and mandible, Only Group 3 showed a significantly lower complete retention rate in mandible than maxilla (p<0.05). 3. In failed surface analysis, occlusal failed surface was 58.3%, buccal/palatal failed surface was 41.7%.

• Microbiology and Biotechnology Letters
• /
• v.15 no.5
• /
• pp.352-355
• /
• 1987

The isolation and characterization of type II restriction endonuclease from Clostridium thermocellum ATCC 27405 were described. This enzyme (Cth I endonuclease) is an isoschizomer of Bcl I endonuclease recognizing 5'-TGATCA-3'. Cth I endonuclease requires MG$^{2+}$ ion for its activity and is maximally active at PH 1.5 to 10.5 in the Presence of 0 to 10mM NaCl. Cth I endonuclease is heat stable and has an optimum temperature of 6$0^{\circ}C$. The activity of Cth I enzyme is sensitive to dam methylation.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.43 no.1
• /
• pp.17-26
• /
• 2016

The use of a rubber dam is a useful technique for protecting patients and operators, producing good results when treating children and adolescent patients. Despite its many advantages, some children and adolescent patients have negative feelings and sometimes express its discomfort. The purpose of this study was to evaluate the patients' preferences for rubber dam use and the associated factors that may affect it. A survey was conducted targeting patients aged 4-18 years old who visited the pediatric dental clinic, the restorative dental clinic, or the student treatment dental clinic of ${\bigcirc}{\bigcirc}$ University Dental Hospital, and were treated using a rubber dam without sedation. We collected questionnaires through electronic medical records. Most children and adolescent patients showed positive attitudes towards using rubber dams. The group with a short treatment time and the group with past knowledge or experience of rubber dam use showed more positive attitudes towards rubber dams (p < 0.05), while no significant difference was found among factors such as gender, age, procedure, anesthetics, treatment site, and operator (p > 0.05).

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.22 no.1
• /
• pp.39-47
• /
• 2022

Background: This was a randomized controlled clinical trial that aimed to evaluate the anesthetic efficacy of 2% lidocaine combined with different concentrations of epinephrine (plain, 1:200,000 and 1:80,000) during endodontic treatment of maxillary molars with symptomatic irreversible pulpitis. Methods: The trial included 144 adult patients who were randomly allocated to three treatment groups. All patients received buccal-plus-palatal infiltration. After 10 min, pulp sensibility testing was performed using an electric pulp test (EPT). If a tooth responded positively, anesthesia was considered to have failed. In the case of a negative EPT response, endodontic access was initiated under rubber dam isolation. The success of anesthesia was defined as having a pain score less than 55 on the Heft Parker visual analog scale (HP VAS), which was categorized as 'no pain' or 'faint/weak/mild' pain on the HP VAS. Baseline pre-injection and post-injection maximum heart rates were recorded. The Pearson chi-square test was used to analyze the anesthetic success rates at 5% significance. Results: Plain 2% lidocaine and 2% lidocaine with 1:200,000 epinephrine and 1:80,000 epinephrine had anesthetic success rates of 18.75%, 72.9%, and 82.3%, respectively. Statistical analysis indicated significant differences between the groups (P < 0.001, 𝛘² = 47.5, df = 2). The maximum heart rate increase was seen with 2% lidocaine solution with epinephrine. Conclusion: Adding epinephrine to 2% lidocaine significantly improves its anesthetic success rates during the root canal treatment of maxillary molars with symptomatic irreversible pulpitis.

• Korean Journal of Ecology and Environment
• /
• v.34 no.1 s.93
• /
• pp.1-8
• /
• 2001

During April 1993 to November 1994, cations, anions, and conductivity were analyzed to examine how summer monsoon influences the ionic content of Taechung Reservoir, Korea. Interannual variability of ionic content reflected hydrological characteristics between the two years(high-flood year in 1993 vs. draught year in 1994). Cations, anions and conductivity were lowest during peak inflow in 1993 and highest during a drought in 1994. Floods in 1993 markedly decreased total salinity as a result of reduced Ca$^{2+}$ and HCO$_{3}\;^{-}$ and produced extreme spatial heterogeneity (i.e., longitudinal, vertical, and horizontal variation) in ionic concentrations. The dominant process modifying the longitudinal (the headwaters-to-downlake) and vertical (top-to-bottom) patterns in salinity was an interflow current during the 1993 monsoon. The interflow water plunged near a 27${\sim}$37 km-location (from the dam) of the mid-lake and passed through the 10${\sim}$30m stratum of the reservoir, resulting in an isolation of epilimnetic high conductivity water (>100 ${\mu}$S/cm) from advected river water with low conductivity (65${\sim}$75 ${\mu}$S/cm), During postmonsoon 1993, the factors regulating salinity differed spatially; salinity of downlake markedly declined as a result of dilution through the mixing of lake water with river water, whereas in the headwaters it increased due to enhanced CaCO$_{3}$ (originated from limestone/metamorphic rock) of groundwaters entering the reservoir. This result suggests an importance of the basin geology on ion compositions with hydrological characteristics. In 1994, salinity was markedly greater (p<0.001) relative to 1993 and ionic dilution did not occur during the monsoon due to reduced inflow. Overall data suggest that the primary factor influencing seasonal ionic concentrations and compositions in this system is the dilution process depending on the intensity of monsoon rainfall.