• Proceedings of the KSME Conference
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• 2003.04a
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• pp.550-557
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• 2003

Hyperelastic constitutive equations for nonlinear deformation of the periodontal ligament were investigated. The parameters in the strain energy potentials were obtained from experimental data for uniaxial and shear responses of the human periodontal ligament. The hyperelastic constitutive equations based on two strain energy potentials was also compared with the linear elastic equation, which is recently reported. The best fitted parameters in the strain energy potentials was applied to finite element program (ABAQUS) to simulate special orthodontic treatment of a mandibular canine.

• Journal of Oral Medicine and Pain
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• v.25 no.1
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• pp.41-51
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• 2000

This study was performed to investigate the effect of three modalities commonly used for reduction of oral malodor and to review the contributing factors for halitosis. For this study, 45 subjects of good general health in their third decades were selected, and they were divided into three groups by each modality, that is, tongue scraping, $ZnCl_2$ mouth rinse, and periodontal treatment. Subjective sense of halitosis, diets, Oral hygiene index based on tooth brushing and tongue brushing habit, resting salivary flow rate, gingival index, degree of tongue coating were recored in the Halito-Chart designed by the author. Oral malodor converted from volatile sulfur compound was measured by the Halimeter$^{(R)}$(Interscan Co., USA), and the correlation between the oral factors and pre-treatment halimeter score were analysed. Data obtained were analysed by the SPSS windows program and the results of this study were as follows : 1. There were no significant correlation between oral factors such as oral hygiene index, salivary flow rate, gingival index, degree of tongue coating and pre-treatment halimeter score. 2. Difference between pre- and post-treatment halimeter score by the three modalities were significant, but correlation between pre- and post-treatment score within group was most significant in the periodontal treatment group followed by the tongue scraping group and lowest in the $ZnCl_2$ mouth rinse group. 3. Reduction of halimeter score was significant only in subjects with relatively more tongue coating in the tongue scraping group, but in the $ZnCl_2$ mouth rinse group and in the periodontal treatment group, the modality applied to each group had same significant effects without regard to the degree of oral hygiene index or gingival index. 4. Men had more tongue coating than women, and reduction of halimeter score was significant in men, but not in women.

• The Korean Journal of Health Service Management
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• v.7 no.2
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• pp.93-100
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• 2013

This study sought to explore the relationships between health behavior, oral health behavior and community periodontal index away the adult in korea. The date of 'The fifth korean national health and nutrition examination survey 2010' was analyzed for this study. The questionnaire was measured regarding health behavior, oral health behavior, community periodontal index and socio-economic characteristics. For statistical analysis, the SPSS 19.0 for Windows was used. We determined frequencies, percentage and determining statistical significance using multiple regression analysis. General characteristics showed differences in community periodontal index associated with residence, gender, age, income level, education, division of basic livelihood security. Health behavior showed differences in community periodontal index associated with smoking, AUDIT. Oral health behaviors showed differences in community periodontal index associated with dental care treatment, utilization of dental hospitals, dental check up, tooth brushing, use oral health supplies. In conclusion, in order to reduce community periodontal index of the adult, the importance and needs of periodontal status should be emphasized. periodontal status related education and program for the adult should be operated.

• Journal of Periodontal and Implant Science
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• v.14 no.1
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• pp.71-71
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• 1984

• Journal of Periodontal and Implant Science
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• v.50 no.5
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• pp.279-280
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• 2020

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.533-547
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• 1997

In periodontics, much progress was made in the understanding of periodontal disease from 1960s to 1980s and in prevention and management of periodontal disease since the end of 1980s. This presentation will discuss about the prevalence of periodontal disease, treatment need, and provision of periodontal treatment in Korea, and how we could manage the periodontal disease efficiently in the future. According to an epidemiological study in Korea, periodontal disease(including gingivitis) was present in 82% of general population and periodontitis in 30-40% in adult population over 30y and juvenile periodontitis in 0.1% of adolescents. If we consider that at least 17% of these patients may have recurrent or refractory forms, there is obviously an abundance of disease that needs treatment, As a result of increase in life expectancy, senile population over 65 y will be increased from 6% in 1996 to 6.9% in 2000, and tooth retention rate and periodontal treatment need are expected to increase. Periodontists need all the help they can get from the general dentists to control periodontal disease. As for provision, postgraduate course in periodontics started in 1957 in Korea and produced over 700 specialized dentists in periodontics. One report indicated that the periodontists as well as general practitioners did periodontal therapy on only a few periodontal patients, because of specific control by current medical insurance system in Korea. Comprehensive periodontal examination is rarely done in local dental clinic. Therefore, enhancement of periodontal care in medical insurance system and education of simplified periodontal examination such as Periodontal Screening & Recording will make dentists diagnose and manage the management of adult patients is based on the recognition that there are multiple diseases, including gingivitis, chronic adlt periodontitis, and other more aggressive forms of periodontitis, and requires the earliest possible recognition of these three disease categories. In this presentation, we discuss practical approach using PSR to diagnose, manage and refer the patients, to facilitate the separation of the simple from the complex and the predictable from the unpredictable form of periodontal diseases and to integrate diagnostic and therapeutic techniques into private practice today.

• Journal of Periodontal and Implant Science
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• v.48 no.5
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• pp.295-304
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• 2018

Purpose: This study was undertaken to evaluate the clinical and microbiological effects of an erythritol powder air-polishing device (EPAP) as a supplement to scaling and root planing (SRP) therapy in patients with moderate chronic periodontitis. Methods: Clinical and microbiological evaluations were performed at 21 sites treated with SRP (control) and 21 sites treated with SRP+EPAP (test). All examinations were performed before treatment, 1 month after treatment, and 3 months after treatment. Results: There were no significant clinical differences between the test group and the control group. Microbiological analysis revealed that the relative expression level of Porphyromonas gingivalis was significantly lower in the test group than in the control group at 1 month after treatment. Clinical and microbiological results showed improvements at 1 month compared to baseline; in contrast, the results at 3 months after treatment were worse than those at 1 month after treatment. Conclusions: In this study, both SRP and SRP+EPAP were clinically and microbiologically effective as non-surgical periodontal treatments. In particular, the SRP+EPAP group showed an antimicrobial effect on P. gingivalis, a keystone bacterium associated with the onset of chronic periodontitis, in a short-term period. Periodic periodontal therapy, at intervals of at least every 3 months, is important for sustaining the microbiological effects of this treatment.

• Journal of Periodontal and Implant Science
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• v.41 no.2
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• pp.92-97
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• 2011

Purpose: The present study was performed to compare the treatment outcomes of non-surgical periodontal treatment according to the distribution of attachment loss of a given patient. Methods: Forty-five patients with moderate to severe periodontitis were divided in two subgroups; Group I patients with teeth manifesting attachment loss of ${\geq}$ 6 mm at one or more sites on the buccal/labial aspect while maintaining an attachment level ${\leq}$ 5 mm at the lingual/palatal aspect, Group II patients with teeth manifesting an attachment level ${\geq}$ 6 mm at more than one site on the lingual/palatal aspect while maintaining an attachment level ${\leq}$ 5 mm at the buccal/labial aspect. The probing pocket depth, probing attachment level, tooth mobility, and chewing discomfort were recorded at baseline and 6 months examinations following non-surgical periodontal therapy. Results: The buccal/ abial surfaces of teeth with moderate to severe periodontitis in Group I patients demonstrated a greater amount of pocket reduction, gain of attachment level, and tooth mobility reduction than the lingual/palatal aspects of teeth examined in Group II patients. Conclusions: Within the limits of the present study, the patients demonstrating attachment loss ${\geq}$ 6 mm at buccal/labial surfaces responded better to the nonsurgical periodontal therapy than those demonstrating comparable attachment loss at lingual/ palatal surfaces.

• The Journal of the Korean dental association
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• v.57 no.12
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• pp.736-746
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• 2019

Supportive periodontal therapy(SPT) is essential for the long-term success of periodontal treatment. A patient's compliance with SPT is one of the most important factors affecting periodontal status. There are few studies quantifying compliance with SPT. The aim of this study is to quantify patient's compliance using new method and evaluate tooth loss depending on patient's supportive periodontal treatment compliance index(SPTCI) with SPT. This study included subjects diagnosed with generalized moderate to severe chronic periodontitis, who had completed active periodontal treatment and had SPT over 5 years in Wonkwang university dental hospital. Chart review and radiography analysis were performed. To quantify compliance, SPTCI representing average of gap between recommended schedules and actual visits has been used and evaluated with tooth loss. Mean period of SPT was 8.9 years and mean SPTCI was about 120. In statical analysis, patients who have higher SPTCI with SPT are more likely to have higher rate of tooth loss. Under SPTCI of 120, there were no significant co-relation between SPTCI and tooth loss. Patients diagnosed with moderate chronic periodontitis have significant co-relation between SPTCI and tooth loss, whereas patients diagnosed with severe chronic periodontitis have no co-relation. SPTCI, new method of quantifying compliance in this study, affected to tooth loss. This study suggests that using SPTCI could be helpful for prediction of tooth loss and be used to determine the interval of visit.

• Journal of Periodontal and Implant Science
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• v.51 no.3
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• pp.163-178
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• 2021

Purpose: The aim of this study was to evaluate clinical factors affecting the longevity of fixed retainers and the influence of fixed retainers on periodontal health in periodontitis patients. Methods: In total, 52 patients with at least 2 years of follow-up after periodontal and orthodontic treatment were included in this study. After scaling and root planing, orthodontic treatment with fixed appliances or clear aligners was performed. Fixed retainers with twist-flex stainless steel wires were bonded to the palatal or lingual sides of anterior teeth. Changes in clinical parameters, including the plaque index, gingival index, calculus index (CI), probing pocket depth, and radiographic bone levels, were evaluated before bonding of fixed retainers and at a 12-month follow-up. Cumulative survival rates (CSRs) for retainer failure were evaluated according to sex, site, CI, stage of periodontitis, and the severity of the irregularity with the log-rank test and hazard ratios (HRs). Results: Twelve months after bonding of fixed retainers, improvements were observed in all clinical parameters except CI and radiographic bone gain. The overall CSR of the retainers with a CI <1 at the 12-month follow-up after bonding of fixed retainers was significantly higher than that of the retainers with a CI ≥1 at the 12-month follow-up (log-rank test; P<0.001). Patients with stage III (grade B or C) periodontitis had a higher multivariate HR for retainer failure (5.4; 95% confidence interval, 1.22-23.91; P=0.026) than patients with stage I (grade A or B) periodontitis. Conclusions: Although fixed retainers were bonded in periodontitis patients, periodontal health was well maintained if supportive periodontal treatment with repeated oral hygiene education was provided. Nonetheless, fixed retainer failure occurred more frequently in patients who had stage III (grade B or C) periodontitis or a CI ≥1 at 12-month follow-up after bonding of fixed retainers.