• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.4
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• pp.317-326
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• 2013

This study was to compare the cumulative survival rate of implant-supported fixed prostheses and to analyze association between risk factors and cumulative survival rate of implant-supported fixed prostheses. In order to assess the clinical status of implant-supported fixed prostheses, individuals who treated in the Department of Prosthodontics, Pusan National University Dental Hospital, between 2000 to 2007 were examined. The results of this study were as follows: 1. Length of service of implant-supported fixed prostheses was $6.6{\pm}32.0$ years (mean), 11.7 years (median). 2. Age and sex of patient was found to have no statistically significant influence on longevity of implant-supported fixed prostheses (P>.05). 3. Reason of tooth extraction wax found to have statistically significant influence on implant-supported fixed prostheses (P<.05). The longevity of fixed prostheses was low in tooth extraction case due to periodontal disease (median:9.0 years). 4. Location of implant-supported fixed prostheses was found to have statistically significant influence on longevity of fixed prostheses (P<.05). The longevity of fixed prostheses was low in molar region (median:8.8 years). 5. Number of units in implant-supported fixed prostheses was found to have no statistically significant influence on longevity of fixed prostheses (P>.05). 6. Condition of opposing dentition was found to have no statistically significant influence on longevity of implant-supported fixed prostheses (P>.05). 7. Food impaction (40.5%), porcelain fracture (25.8%), screw loosening (23.6%) were frequent complications.

• Journal of dental hygiene science
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• v.11 no.6
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• pp.535-542
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• 2011

The purpose of this study was to examine the state of smoking among adolescents and their smoking-related oral health knowledge. The subjects in this study were the teens who were selected by convenience sampling from among the students who were in their first, second and third years in four different middle schools in the city of Iksan, North Jeolla Province. A self-administered survey was conducted from June 14 to July 12, 2011, and the answer sheets from 1,219 respondents were selected for analysis. The collected data were analyzed by the statistical package 12.0, and the findings of the study were as follows: 1. The smoker students accounted for 10.6 percent. The boys and girls who smoked respectively represented 16.0 and 5.4 percent. 2. As for the period of smoking, the largest group that accounted for 51.6 percent smoked for less than a year. Concerning the amount of daily smoking, the greatest group that accounted for 91.9 percent smoked less than 10 cigarettes. As to the motivation of smoking, the biggest group that represented 52.8 percent started to smoke out of curiosity. 3. Regarding smoking-related oral health knowledge, they got a mean of 0.85. Their scores in knowledge of oral malodor(0.95), oral cavity cancer(0.94) and periodontal diseases(0.93) were above the average, and their scores in knowledge of dental caries(0.70) and blunting of taste(0.77) were below the average. 4. The seventh graders got the best score of 5.28 in smoking-related oral health knowledge(p<0.01), and the students who were more satisfied with their life had a better oral health knowledge(p<0.05). 5. The senior students were more dependent on nicotine(p<0.01), and the number of smoking days(${\beta}=0.407$, p<0.001) and the period of smoking(${\beta}=0.235$, p<0.01) affected their nicotine dependence.

• Journal of dental hygiene science
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• v.10 no.6
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• pp.473-479
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• 2010

This study purposed to survey D university students' perception of kindness in their use of dental care services in an area of Gyeonggido. For this purpose, we conducted a questionnaire survey of 502 students from October 2, 2008 to March 6, 2009 and analyzed the data. Results obtained from this study are as follows. 1. Of the subjects, 71.3% were female, 67.7% were at the age of 20 or younger, and 89.2% had experience in visiting a dental clinic. Among the subjects who had experience in visiting a dental clinic, 31.1% replied that they were highly interested in oral health, and to the question on the selfperceived current oral health condition, 35.1% replied that there was something wrong in their oral health condition. 2. With regard to correlation between general characteristics and interest in oral health, 79.9% of the male subjects and 83.2% of the female ones were highly interested in oral health. According to age, interest in oral health was highest among those aged 26 or older 92.0%. 3. With regard to correlation between general characteristics and oral health condition, if the presence of dental caries or periodontal disease was considered an indicator of poor oral health, 66.0% of the male subjects and 70.9% of the female ones appeared unhealthy, 72.0% of students aged 26 or older showed satisfaction. 4. The most frequent reason for not visiting a dental clinic was 'Not sick' 34.6%, and among those who had experience, the most frequent reason for visiting was 'To get treatment of sick teeth' 63.0%. With regard to the perceived kindness of dentist and dental hygienist, 40.6% and 45.8% of the subjects, respectively, were highly satisfied. The most frequent reason for satisfaction was 'Comfortable with patient reception' 34.4% and the most frequent reason for dissatisfaction was 'Explain treatment insufficiently' 30.7%. 5. As to perceived kindness according to gender, 60.9% of the male subjects and 56.1% of the female ones were satisfied with dentist's kindness, and 66.9% and 59.6%, respectively, were satisfied with dental hygienist's kindness. According to age, 62.5% of students aged 26 or older showed satisfaction with dentist's kindness and 78.3% of them with dental hygienist's kindness. 6. As to perceived kindness according to correlation between interest in oral health and current selfperceived oral condition, the kindness of dentists(68.0%) and hygienists(67.8%) was perceived higher when interest in oral health was high and not very interested and the kindness of dentists(50.0%) and hygienists(66.78%) when selfperceived oral condition was healthy, and the difference was statistically significant (p<.022 and p<.023, respectively).

• Journal of dental hygiene science
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• v.17 no.2
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• pp.123-133
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• 2017

The aim of this study was to analyze in depth the standardized Clinical dental hygiene curriculum of the Fones School in the United States. We investigated the clinical dental hygiene curriculum in 2015~2016 including title, credit, hours, contents, goals, competencies, and evaluation. We obtained the course syllabus and data related to each subject, for each grade, from the professors and students at the university. The goals and competencies, of the clinical dental hygiene program, which were based on the goals of the Fones School and the mission of the University of Bridgeport, were developed in accordance with the dental hygienist practice standards proposed by the American Dental Hygienists Association. The curriculum consisted of theory to teach proper dental hygiene care procedures and incorporated practical exercises that modeled an actual clinical setting. The students had to document the procedures performed for each client/patient and improve their clinical competency through discussion with the professors. Dental hygiene care should be provided for children, adolescents, adults, elderly, and patients, which includes patients with moderate or severe periodontal status. Students were evaluated by a paper test or case study presentation and their clinical evaluation was based on their clinical competency. In particular, professors evaluated students on a rotational basis, so they could evaluate the level of achievement of clinical competency of all students and find ways to improve any weaknesses. Therefore, the current study suggested that clinical dental hygiene program in Korea could be improved if based on the curriculum of Fones School in the United States.

• The korean journal of orthodontics
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• v.41 no.5
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• pp.324-336
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• 2011

Objective: The aim of this study was to conduct three-dimensional finite element analysis of individual tooth displacement and stress distribution when a posterior retraction force of 200 g was applied at different positions of the retraction hook on the transpalatal arch (TPA) of a molar, and over different lengths of the lever arm on the maxillary anterior teeth in lingual orthodontics. Methods: A three-dimensional finite element model, including the entire upper dentition, periodontal ligaments, and alveolar bones, was constructed on the basis of a sample (Nissan Dental Product, Kyoto, Japan) survey of Asian adults. Individual movement of the incisal edge and root apex was estimated along the x-, y-, and z-coordinates to analyze tooth displacement and von Mises stress distribution. Results: When the length of the lever arm was 15 mm and 20 mm, the incisal edge and root apex of the anterior teeth was displaced lingually, with a maximum lingual displacement at the lever arm length of 20 mm. When the posterior retraction hook was on the root apex, the molars showed distal displacement. When the length of the lever arm was 20 mm, anterior extrusion was reduced and the crown of the canine displaced toward the buccal side, in which case, the retraction hook was on the edge, rather than at the center, of the TPA. Conclusions: The results of the analysis showed that when 6 anterior teeth were retracted posteriorly, lateral displacement of the canine and lingual displacement of the incisal edge and root apex of the anterior teeth occur without the extrusion of the anterior segment when the length of the lever arm is longer, and the posterior retraction hook is in the midpalatal area.

• Journal of dental hygiene science
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• v.14 no.3
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• pp.287-294
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• 2014

The purpose of this study is to use basic data of dental hygiene curriculum with a new technique called motivational interviewing of communication skill to demonstrate the effectiveness of the method of oral health care. In this study, we performed oral health care program that has been made in dental hygiene department to university students. It was assigned to the control group and 66 and 32 experimental group based on the date of the first visit time. It conducted motivational interviewing of a total of three times in the experimental group. The analytical results of the measurements obtained in the oral examination and questionnaires. The results were as follows: The experimental group measured value was reduced after the intervention compared to before the PSR to evaluate the state of periodontal, gingival index, calculus index, plaque control record (PCR; O'Leary plaque index), simple plaque scor of Quantitative Light Induced Fluorescnece Digital measurement value (p<0.05). Experimental group decreased more and more the result of changes in the reduction of the average of the PCR. But control group was reduced to 3 weeks and increased back to the middle 16 weeks. There was also support interaction between the measurement point and the groups (p<0.05). Re-visit adherence of fit, 12.1% in the control group, the experimental group was 43.7% in the period of participation in the oral health care program. Thus, visit adherence of the experimental group was higher. In this study, a group that has motivational interviewing, It was able to confirm the improvement of oral health state. Discussion of the motivational interviewing can be applied to oral health care program.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.555-565
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• 2006

The purpose of the present study is to evaluate the biological stability of the zirconia/alumina composite abutment by histologic and radiographic examination in clinical cases. 17 partially edentulous patients (5 men and 12 women, mean age 47) were treated with 37 implants. The implants were placed following the standard two-stage protocol. After a healing period of 3 to 6 months, zirconia/alumina composite abutments were connected. All radiographs were taken using paralleling technique with individually fabricated impression bite block, following insertion of the prosthesis and at the 3-, 6-, 12 month re-examinations. After processing the obtained images, the osseous level was calculated using the digital image in the mesial and distal aspect in each implant. An ANOVA and t-test were used to test for difference between the baseline and 3-, 6-, 12 months re-examinations, and for difference between maxilla and mandible. Differences at P <0.05 were considered statistically significant. For histologic examination, sample was obtained from the palatal gingiva which implant functioned for 12 months. Sections were examined under a light microscope under various magnifications. Clinically, no abutment fracture or crack as well as periimplantitis was observed during the period of study. The mean bone level reduction(${\pm}standard$ deviation) was 0.34 rom(${\pm}\;0.26$) at 3-months, 0.4 2mm(${\pm}\;0.30$) at 6-months, 0.62 mm(${\pm}\;0.28$) at 12-months respectively. No statistically significant difference was found between baseline and 3-, 6-, 12-months re-examinations (p > 0.05). The mean bone level reduction in maxilla was 0.33(${\pm}0.25$) at 3-months, 0.36(${\pm}0.33$) at 6-months, 0.56(${\pm}0.26$) at 12-months. And the mean bone level reduction in mandible was 0.35(${\pm}0.27$) at 3-months, 0,49(${\pm}0.27$) at 6-months, 0.68(${\pm}0.30$) at 12-months. No statistical difference in bone level reduction between implants placed in the maxilla and mandible. Histologically, the height of the junctional epithelium was about 2.09 mm. And the width was about 0.51 mm. Scattered fibroblasts and inflammatory cells, and dense collagen network with few vascular structures characterized the portion of connective tissue. The inflammatory cell infiltration was observed just beneath the apical end of junctional epithelium and the area of direct in contact with zirconia/alumina abutment. These results suggest the zirconia/alumina composite abutment can be used in variable intraoral condition, in posterior segment as well as anterior segment without adverse effects.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.345-359
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• 2006

Loss of maxillary molar teeth leads to rapid loss of crestal bone and inferior expansion of the maxillary sinus floor (secondary pneumatization). Rehabilitation of the site with osseointegrated dental implants often represents a clinical challenge because of the insufficient bone volume resulted from this phenomenon. Boyne & James proposed the classic procedure for maxillary sinus floor elevation entails preparation of a trap door including the Schneiderian membrane in the lateral sinus wall. Summers proposed another non-invasive method using a set of osteotome and the osteotome sinus floor elevation (OSFE) was proposed for implant sites with at least 5-6mm of bone between the alveolar crest and the maxillary sinus floor. The change of grafted material in maxillary sinus is important for implant survival and the evaluation of graft height after maxillary sinus floor elevation is composed of histologic evaluation and radiomorphometric evaluation. The aim of the present study was radiographically evaluate the graft height change after maxillary sinus floor elevation and the influence of the graft material type in height change and the bone remodeling of grafts in sinus. A total of 59 patients (28 in lateral approach and 31 in crestal approach) who underwent maxillary sinus floor elevation composed of lateral approach and crestal approach were radiographically followed for up to about 48 months. Change in sinusgraft height were calculated with respect to implant length (IL) and grafted sinus height(BL). It was evaluated the change of the graft height according to time, the influence of the approach technique (staged approach and simultaneous approach) in lateral approach to change of the graft height, and the influence of the type of graft materials to change of the graft height. Patients were divided into three class based on the height of the grafted sinus floor relative to the implant apex and evaluated the proportion change of that class (Class I, in which the grafted sinus floor was above the implant apex; Class II, in which the implant apex was level with the grafted sinus floor; and Class III, in which the grafted sinus floor was below the implant apex). And it was evaluated th bone remodeling in sinus during 12 months using SGRl(by $Br\ddot{a}gger$ et al). The result was like that; Sinus graft height decreased significantly in both lateral approach and crestal approach in first 12 months (p$MBCP^{TM}$ had minimum height loss. Class III and Class II was increased by time in both lateral and crestal approach and Class I was decreased by time. SGRI was increased statistically significantly from baseline to 3 months and 3 months(p<0.05) to 12 months(p$ICB^{(R)}$ single use, more reduction of sinusgraft height was appeared. Therefore we speculated that the mixture of graft materials is preferable as a reduction of graft materials. Increasing of the SGRI as time goes by explains the stability of implant, but additional histologic or computed tomographic study will be needed for accurate conclusion. From the radiographic evaluation, we come to know that placement of dental implant with sinus floor elevation is an effective procedure in atrophic maxillary reconstruction.

• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.321-333
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• 2005

1. 목적 in vitro 상에서 법랑기질유도체가 치주인대섬유아세포, 불멸화 조골세포와 백악질 유래세포의 증식과 유전자 발현에 미치는 영향을 알아보고자 하였다. 2. 연구방법 및 재료 <세포증식 연구> 교정을 목적으로 발거한 치아에서 분리, 배양한 치주인대섬유아세포와 백악질유래세포, 그리고 $SaOs_2$ 세포를 이용하였다. 법랑기질유도체가 세포 증식에 미치는 영향을 알아보기 위해, 35 mm Petri dish에 dish 당 $5{\times}10^3$ 개의 세포를 접종하였다. 대조군은 1% 항생제와 10% FBS를 포함한 DMEM 배지를 이용했고, 5mM 초산을 첨가한 군과 첨가하지 않은 두 개의 대조군이 이용되었다. 실험군은 100 ${\mu}g/ml$의 법랑기질유도제를 첨가한 군과 100 ${\mu}g/ml$의 법랑기질유도체와 5 mM의 초산을 첨가한 2개의 실험군이 이용되었다. 각 군은 세 개의 배양접시에 행해졌고, 1, 3, 8일에 세포의 수를 각각 측정하였다. 결과는 repeated measures ANOVA로 통계 처리하였다. <유전자 발현 연구> 각 세포의 형질 특성을 알아보기 위해 RT-PCR을 실시하여 조골세포 분화 표식자와 연관된 Human collagen type I(COL I), human osteopontin(OP), human osteocalcin(OC), human alkaline phosphatase(ALP)와 human bone sialoprotein(BSP)의 mRNA 발현을 실험 1, 3, 8일에 걸쳐, 세 군의 차이를 비교 관찰하였다. 3. 결과 <세포증식 연구> 치주인대세포와 백악질유래세포, 그리고 $SaOs_2$ 세포의 증식은 법랑기질유도체에 의해 영향을 받지 않았다. 대조군과 초산이 포함된 대조군 그리고 법랑기질유도체와 초산이 포함된 실험군에서 유의할 만한 세포 수의 차이가 실험 기간 1, 3, 8일에 걸쳐 나타나지 않았다(p<0.05). <유전자 발현 연구> ALP와 COL I은 세 군의 세포에서 모두 발현되었고, 발현 정도는 EMD에 영향을 받지 않았다. OC은 세 군에서 모두 비교적 약하게 발현되었고, 특히 $SaOs_2$ cell과 백악질유래세포에서 약하게 발현되었다. EMD는 OC의 발현정도를 약하게 하였다. OP은 백악질유래세포에서 1, 3, 8일에 걸쳐 EMD 유무에 관련 없이 발현되지 않았다. 그러나 치주인대세포와 $SaOs_2$ cell에서는 강하게 발현되었다. BSP는 치주인대세포와 $SaOs_2$ cell에서 1, 3, 8일에 걸쳐 비교적 고르게 발현되었다. EMD 배지에서 배양된 백악질유래세포는 8일에는 BSP가 발현되지 않았다. 4 결론 이번 실험 결과에 의하면 법랑기질유도체는 치주인대세포, 불멸화 조골세포와 백악질 유래세포의 증식에 있어 유의성 있는 효과를 나타내지 않았다. 그러나, 유전자 발현에 있어서는, 치주인대세포와 백악질유래세포, 그리고 $SaOs_2$ 세포 모두에서 OC mRNA의 발현을 억제하는 효과를 나타내었다. EMD는 세포의 증식에는 영향을 미치지 않지만, 유전자 발현에 있어 일부 영향을 미치는 것으로 보인다. 법랑기질유도체가 세포의 증식과 유전자 발현에 미치는 영향은 배양된 세포의 형질특성, 배양환경, 배양일수 등에 따라 달라질 수 있다. 그러므로 법랑기질유도체가 in vitro 상에서 세포에 미치는 영향은 보다 정량화된 연구가 필요하다.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.99-107
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• 2009

Statement of problem: Restoring and replacing teeth with fixed prostheses commonly used in dental practice. Because of improper oral hygiene care and inaccurate laboratory procedure, complications of fixed prostheses were found in the mouth of patients. Although many efforts have been continually made to obtain the data of long term prognosis of fixed prostheses, it was difficult to do it. Purpose: The purpose of this study was to evaluate the clinical status of fixed prostheses. Material and methods: In order to assess the clinical status of fixed prostheses, a total of 161 individuals(aged 17-85, 99 women and 62 men with 1596 unit of fixed prostheses, and 1169 abutments) who first visited the Department of Prosthodontics, Pusan National University Hospital, between April to September, in 2007 were examined. Results and conclusion: The results of this study were as follows: 1. Length of service of fixed prostheses was $8.6{\pm}0.6$ years(mean), 10.0 years(median). 2. Location of fixed prostheses was found to have no statistically significant influence on longevity of fixed prostheses(P>.05). But, the success rate was high in posterior region and in mandible where the failure rate was high in combination(P<.05). 3. Longevity of fixed prostheses made of metal was longest(mean: $13.0{\pm}9.3$, median: 14.0), gold, precious ceramic, non-precious ceramic trailing behind(P<.05). 4. Number of units in fixed prostheses was found to have no statistically significant influence on longevity of fixed prostheses(P>.05). But, the success rate was high in Single-unit and the failure rate was high in over 3-unit(P<.05). 5. Condition of opposing dentition was found to have no statistically significant influence on longevity of fixed prostheses(P>.05). But, the success rate was high in natural dentition(P<.05). 6. Defective margin(28.2%), dental caries(23.0%), periodontal disease(19.3%), periapical disease(16.9%) were frequent complications. In 30.1% of the cases, abutment state after removing fixed prostheses was needed to be extracted.