• Journal of Korean society of Dental Hygiene
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• v.12 no.3
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• pp.495-501
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• 2012

Objectives : Today, one of the most basically used procedures to dental patients is scaling for removing tartar. The purpose of this study is the effect of Happycaine during scaling for pain relief. Methods : This study was used self-questionnaire from 202 patients. SPSS 18.0 vision program was used for data analysis. Group A was used Happycaine, but group B wasn't used Happycaine. The degree of pain relief depending on use of Happycaine, was analyzed by Independent-two-sample t-test. Emotion and reaction during scaling was analyzed by mean and standard deviation. The results were as follows. Results : 1. 52.5% participants answered 'require scaling' and 12.9% answered 'required scaling very much'. so 65.4% participants recognized the need of scaling. 2. According to the experience of Happycaine during scaling, differences in pain was by Likert 5 pints scale, Group B's pain was higher than Group A's(p=0.000). 3. According to the experience of Happycaine during scaling, the mean of panic from Group B was a little higher than Group A(p=0.036). In case of cold symptom during scaling, Group B was significantly different(p=0.011). In Group B, pain from dental hygienists was significantly different (p=0.000). Group A was interested in Happycaine use in future scaling(p=0.004). Conclusions : As a result of this study, we recommend Happycaine during scaling in order to decrease mental burden and pain for patients.

• Journal of Korean society of Dental Hygiene
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• v.17 no.3
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• pp.539-551
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• 2017

Objectives: The purpose of this study was to investigate the changes in factors on unmet dental scaling rate before and after the national health insurance. Methods: This study used the $2^{nd}$ data from the Community Health Survey. The study participants numbered 209,341 in 2011 and 219,517 in 2013.The average age was $51{\pm}17$ in 2011 and $52{\pm}17$ in 2013. Data were analyzed by descriptive statistics, chi -squared test and logistic regression using SPSS 23.0. Results: The scaling experienced rate of Korean adults has fallen by 3.5% from 66% to 69.5%. Logistic regression analysis showed that 2.7 times more 'people who were educated at elementary school level or lower' did not use dental scaling compared to higher educated children. Agriculture, forestry and fisheries workers did not use scaling at 2.0 times. Local residents with an income of less than one million won did not use 1.7times scaling. Local residents of 'no private insurance' did not use scaling at 1.5 times. In the case of the predisposing factors, the 20s had less than 1.8 times scaling compared to 50s. In the case of needs factor, local residents who experienced 'bad oral health status' and 'dental calculus' were treated scaling 1.3 times less compared to people with good oral health status and normal periodontal symptoms. Conclusions: In Korea, local residents are less frequently treated scaling due to enabling factors such as accessibility. In addition, predisposing factors such as age and sex, and oral health status and periodontal symptoms were related to not using the dental scaling. Therefore, the universality of health care services should be considered so that people who need periodontal care can use scaling.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.12
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• pp.1089-1096
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• 2015

A marine helicopter should remain sufficiently upright to permit safe evacuation of all personnel with a flotation system. And the rule requires that after ditching in water, the adequate flotation time will allow the occupants to leave the rotorcraft. To this end, stability test of the emergency flotation system for Korean marine helicopter was performed by using "Froude scaling method" in water tank. Test configuration and conditions were determined in consideration of the helicopter loading condition and related specifications. Test results meet the stability requirements at sea state code 4 and sea state code 2 with puncture conditions.

• International Journal of Highway Engineering
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• v.16 no.6
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• pp.27-37
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• 2014

PURPOSES : The purpose of this study is to verify the causes of surface scaling at L-shoulder concrete structure. METHODS : From the literature reviews, mechanisms of frost damage were studied and material properties including strength, air void, spacing factor and scaling resistance of L-shoulder concrete structure were analyzed using core specimens taken by real fields. RESULTS : The spacing factor of air void has relatively high correlation of surface conditions : lower spacing factor at good surfacing condition and vice versa. If the compressive strength is high, even thought spacing factor does not reach the threshold value of reasonable durability, the surface scaling resistance shows higher value. Based on these test results, the compressive strength also provide positive effect on the surface scaling resistance. CONCLUSIONS : The main causes of surface scaling of L-shoulder could be summarized as unsuitable aid void amount and poor quality of air void structure. Secondly, although the compressive strength is not the governing factor of durability, but it shows the positive effect on the surface scaling resistance.

• The Journal of Advanced Prosthodontics
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• v.9 no.3
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• pp.188-194
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• 2017

PURPOSE. This study was to evaluate the effect of repeated ultrasonic scaling and surface polishing with intraoral polishing kits on the surface roughness of three different restorative materials. MATERIALS AND METHODS. A total of 15 identical discs were fabricated with three different materials. The ultrasonic scaling was conducted for 20 seconds on the test surfaces. Subsequently, a multi-step polishing with recommended intraoral polishing kit was performed for 30 seconds. The 3D profiler and scanning electron microscopy were used to investigate surface integrity before scaling (pristine), after scaling, and after surface polishing for each material. Non-parametric Friedman and Wilcoxon signed rank sum tests were employed to statistically evaluate surface roughness changes of the pristine, scaled, and polished specimens. The level of significance was set at 0.05. RESULTS. Surface roughness values before scaling (pristine), after scaling, and polishing of the metal alloys were $3.02{\pm}0.34{\mu}m$, $2.44{\pm}0.72{\mu}m$, and $3.49{\pm}0.72{\mu}m$, respectively. Surface roughness of lithium disilicate increased from $2.35{\pm}1.05{\mu}m$ (pristine) to $28.54{\pm}9.64{\mu}m$ (scaling), and further increased after polishing ($56.66{\pm}9.12{\mu}m$, P<.05). The zirconia showed the most increase in roughness after scaling (from $1.65{\pm}0.42{\mu}m$ to $101.37{\pm}18.75{\mu}m$), while its surface roughness decreased after polishing ($29.57{\pm}18.86{\mu}m$, P<.05). CONCLUSION. Ultrasonic scaling significantly changed the surface integrities of lithium disilicate and zirconia. Surface polishing with multi-step intraoral kit after repeated scaling was only effective for the zirconia, while it was not for lithium disilicate.

• The Korean Journal of Applied Statistics
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• v.30 no.4
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• pp.567-578
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• 2017

Grouped multivariate data can be tested for differences between two or more groups using multivariate analysis of variance (MANOVA). However, this method cannot be used if several assumptions of MANOVA are violated. In this case, multidimensional scaling (MDS) and analysis of distance (AOD) can be applied to grouped dissimilarities based on the various distances. A permutation test is a non-parametric method that can also be used to test differences between groups. MDS is used to calculate the coordinates of observations from dissimilarities and AOD is useful for finding group structure using the coordinates. In particular, AOD is mathematically associated with MANOVA if using the Euclidean distance when computing dissimilarities. In this paper, we study the between and within group structure by applying MDS and AOD to the grouped dissimilarities. In addition, we propose a new test statistic using the group structure for the permutation test. Finally, we investigate the relationship between AOD and MANOVA from dissimilarities based on the Euclidean distance.

• Journal of Korean society of Dental Hygiene
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• v.13 no.6
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• pp.977-985
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• 2013

Objectives : The purpose of the study is to investigate Korean scaling fear (KSF)-1.1 and related factors in scaling patients. Methods : The subjects were 314 scaling patients in 7 dental clinics in Daegu from April to June, 2013. Data were analyzed for simple frequency rate, t-test and ANOVA(Sheffes's post hoc) for the identification of the differences between KSF-1.1 and variables. Multiple regression was analyzed for the impact of independent variable on the score of KSF-1.1. Results : Mean score of KSF-1.1 in 314 scaling patients was 2.60. Female patients (2.71) had a higher score than male (2.47) (p<0.01). Those who didn't get a regular dental check up(2.87) tended to have higher fear level than those who had regular checkup (2.46) (p<0.001). Those who experienced dental pain (2.90) had significantly higher score than those who had not (2.46) (p<0.001). There was a significant difference between three groups (yes 3.03, ordinary 2.79, and no 2.42) in scaling (p<0.001) and financial burden (p<0.001). Variables associated with score of KSF-1.1 were gender(${\beta}$=0.21, p<0.05), waiting time for scaling(${\beta}$=0.24, p<0.01) and financial burden (${\beta}$=0.22, p<0.02) by multiple regression analysis. Conclusions : The influencing factors of scaling were gender, financial burden, waiting time for scaling that may effect on a score of KSF-1.1.

• The Journal of Korean Physical Therapy
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• v.20 no.3
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• pp.45-51
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• 2008

Purpose: We evaluated the physical stress and pain to the musculoskeletal system of a dental practitioner when engaging in a dental scaling training exercise to prevent the development of musculoskeletal injuries. Methods: The 18 female (average age: 21$\pm$1 years) subjects were voluntarily picked from a group of juniors who have completed a one-and-a-half year training course that includes training exercises on the dentiform and on live subjects (other trainees). The test is done by measuring pain, activity, grip strength, and finger dexterity for each subject's hand and wrist. Before the test all subjects were confirmed to be right-handed and were informed of the study and its objective. Measuring was done before and after each subject performed dental scaling for one hour using the scaler and the curet. Results: Pain levels increased for both hand and shoulders, but hand pain was often greater than shoulder pain. Grip strength significantly declined in the right hand but not the left. For joint mobility, the flexion and the extension for the shoulder joint did not change; but the range of motion for both wrist joints significantly increased. For the dexterity test, both hands showed increased dexterity after the exercise. Conclusion: Dental scaling can affect the shoulders and wrists/hands. Therefore, a musculoskeletal injury prevention program for dental practitioners, which may include encouraging them to assume correct body posture when at work, must be sought. This study evaluated only the shoulders, wrists, and hands; but future studies should include areas such as the cervical area, the back, and the lower limbs.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.575-584
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• 1997

The quality of periodontal instrument cutting edge is a basic element of effective root planing procedure. Using instruments, the sharp edge is changed into blunt or beveled edge. With the blunt instrument, the periodontal treatment can't be carried into accuracy and effective. The study on the wear of periodontal curet is insufficient, there are few publications about the change of sharpness of cutting egde after using instrument and a certen reports were published on the study of scanning electron microscope(SEM) examination. In this study, to declare the number of strokes for sharpening of instruments, the changes of cutting edge is measured by the clinical methods, tactile sensitivity examination and refraction light-white line test after scaling strokes and root planing strokes. SEM test was added for defined the changes of cutting edges. The 7/8 Gracey curets that have been never used was tested. Maxillary molars which were extracted from the School of Dental Medicine, Dankook University was used. Subjected teeth had attachment loss more than 6 mm in bucca-lingual surface and sufficient calculus of a band type in cervical area. The strokes of curet were executed 3, 5, 7, 9, 11, 13 times on scaling stroke and 10, 15, 20, 25, 30, 35 times on root planing stroke. A resident has periodontal experience over 3 years carried out the clinical examinations those tactile sensitivity examination and refraction light-white line test 5 times. The case there being tactile sensitivity certenly is 2, the case being felt tactile sensitivity is 1, and the case there not being tactile sensitivity is 0. The visual examination was recorded as following. The case that refracted white line is not recognised is 2, the case that uncerten is 1, and the case that acknowledged is 0. The results were obtained as follows. 1. After scaling strokes, the tactile sensitivity was reduced after 11 strokes and disappeared in 13 strokes. 2. In tactile sensitivity after root planing procedures, sensitivity was reduced after 25 strokes and disappeared in 35 strokes. 3. In case of visual examination, the detection of refracted white line was increased after 9 strokes of scaling procedures and the accuracy of wear wasn't showed after root planing procedures. 4. In SEM, metal projection was observed on new periodontal curet cutting edge and it was disappeared after scaling procedures. 5. In SEM, the cutting edge was showed changing linear into an aspect of the surface after 5 strokes of scaling procedures and 10 strokes of root planing procedures and showed beveled edge in 11 strokes of scaling procedures, 25 strokes of root planing procedures. The results of 3-type examination indicated that the sharpening of curet should be performed after 11 strokes of scaling procedures and 25 strokes of root planing procedures.

• Fire Science and Engineering
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• v.13 no.4
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• pp.30-37
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• 1999

In this study, reduced-scale experiments as the alternative to a real-scale fire test were conducted to understand fire properties in atrium space. The scaling laws were derived from $\pi$-parameters which were deduced by dimensional analysis of governing equations (continuity, conservation of momentum and conservation energy). The 1/50 scale experiment simulated the real-scale fire test in SIVANS atrium at Japan were conducted under the scaling laws. And this results were compared with real-scale experiment results. Furthermore these results were visualized by video recording system using laser light sheet.