녹차추출물 (-)-Epigallocatechin-3-gallate가 사람치주인대섬유모세포 활성 유지에 미치는 영향

정임희,윤정호,정의원,김창성,김남희,정원균,최성호 한국생체재료학회 2010 생체재료학회지 Vol.14 No.3

The purpose of this study was to evaluate the effect of (-)-Epigallocatechin-3-gallate (EGCG) on the viability of human periodontal ligament fibroblast (hPDLF). Firstly, various concentration of EGCG were applied to hPDLF for 8 days, and then 10 μM EGCG was put for the first 6 days to the experimental group and was stopped for the next 8days. For the positive control group, the 10 μM EGCG was supplied during the whole period, while any EGCG was not supplied for the negative control. Cell viability was analyzed with MTT assay. In the first experiment, the group which treated 10 μM EGCG for 6days showed highest cell viability. In the second treatment, the negative control showed continuous growing up in cell proliferation until 12th day and then a little decreased. After stopping EGCG supply, the experimental group’s proliferation was slightly cut down and then showed big increases. Lastly, the positive control°Øs increase was lasted during the whole period, but there was no a large variance and it showed lowest cell viability on 14th day. From these results, we concluded that EGCG do not affect such a lot on the increase of hPDLF proliferation,but it is possible for EGCG to make hPDLF hibernate with proper concentration of EGCG.

Anti-inflammatory effect of (–)-epigallocatechin- 3-gallate on Porphyromonas gingivalis lipopolysaccharide-stimulated fibroblasts and stem cells derived from human periodontal ligament

정임희,이동은,윤정호,조아란,김창성,유윤정,김성조,최성호 대한치주과학회 2012 Journal of Periodontal & Implant Science Vol.42 No.6

Purpose: (–)-epigallocatechin-3-gallate (EGCG) has been reported to exert anti-inflammatory and antibacterial effects in periodontitis. However, its exact mechanism of action has yet to be determined. The present in vitro study evaluated the anti-inflammatory effects of EGCG on human periodontal ligament fibroblasts (hPDLFs) and human periodontal ligament stem cells (hPDLSCs) affected by bacterial lipopolysaccharide (LPS) extracted from Porphyromonas gingivalis. Methods: hPDLFs and hPDLSCs were extracted from healthy young adults and were treated with EGCG and/or P. gingivalis LPS. After 1, 3, 5, and 7 days from treatment, cytotoxic and proliferative effects were evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and bromodeoxyuridine assay, respectively. And then, the gene expressions of hPDLFs and hPDLSCs were observed for interleukin (IL)-1β , IL-6, tumor necrosis factor (TNF)-α , osteoprotegerin (OPG), receptor activator of nuclear factor kappa-B ligand (RANKL), and RANKL/OPG using real-time polymerase chain reaction (PCR) at 0, 6,24, and 48 hours after treatment. The experiments were performed with the following groups for hPDLFs and hPDLSCs; 1) No treat, 2) EGCG alone, 3) P. gingivalis LPS alone, 4) EGCG+ P. gingivalis LPS. Results: The 20 μM of EGCG and 20 μg/mL of P. gingivalis LPS had the lowest cytotoxic effects, so those concentrations were used for further experiments. The proliferations of hPDLFs and hPDLSCs increased in all groups, though the ‘EGCG alone’showed less increase. In real-time PCR, the hPDLFs and hPDLSCs of ‘EGCG alone’ showed similar gene expressions to those cells of ‘no treat’. The gene expressions of ‘P. gingivalis LPS alone’ in both hPDLFs and hPDLSCs were highly increased at 6 hours for IL-1β , IL-6, TNF-α , RANKL, and RANKL/OPG, except the RANKL/OPG in hPDLSCs. However, those increased gene expressions were down-regulated in ‘EGCG+P. gingivalis LPS’ by the additional treatment of EGCG. Conclusions: Our results demonstrate that EGCG could exert an anti-inflammatory effect in hPDLFs and hPDLSCs against a major pathogen of periodontitis, P. gingivalis LPS.

Effect of (-)-epigallocatechin-3-gallate on maintaining the periodontal ligament cell viability of avulsed teeth: a preliminary study

정임희,윤정호,김창성,정원균,최성호,Ah-Ran Cho 대한치주과학회 2011 Journal of Periodontal & Implant Science Vol.41 No.1

Purpose: Avulsed tooth can be completely recovered, if sound periodontal ligament (PDL) of tooth is maintained. Although a lot of storage solutions have been explored for the better storage of avulsed tooth, there is a shortcoming that the preservation time is much short. On the other hand, there has been studies that (-)-epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea, which is related to the anti inflammatory, antioxygenic, and antibacterial effects, allows the successful preservations of tissues and cells. This study evaluated the effect of EGCG on avulsed-teeth preservation of Beagle dogs for a period of time. Methods: The atraumatically extracted teeth of Beagle dogs were washed and preserved with 0/10/100 µM of EGCG at the time of immediate, period 1 (4 days in EGCG-contained media and additional 1 day in EGCG-free media), period 2 (8 days in EGCG-contained media and additional 2 days in EGCG-free media) and period 3 (12 days in EGCG-contained media and additional 2 days in EGCG-free media). Then, the cell viabilities of preserved teeth was calculated by dividing optical density (OD)of 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay with OD of eosin assay to eliminate the measurement errors caused by the different tissue volumes. Results: From the results, the immediately analyzed group presented the highest cell viability, and the rate of living cells on teeth surface decreased dependent on the preservation period. However, the 100 µM of EGCG-treated group showed statistically significant positive cell activity than EGCG-free groups throughout preservation periods. Conclusions: Our findings showed that 100 µM EGCG could maintain PDL cell viability of extracted tooth. These results suggest that although EGCG could not be a perfect additive for tooth preservation, it is able to postpone the period of tooth storage. However, further in-depth studies are required for more plausible use of EGCG.

Comparative analysis of carrier systems for delivering bone morphogenetic proteins

정임희,임현창,이중석,정의원,최성호 대한치주과학회 2015 Journal of Periodontal & Implant Science Vol.45 No.4

Purpose: The objective of this study was to comparatively assess the bone regenerative ca¬pacity of absorbable collagen sponge (ACS), biphasic calcium phosphate block (BCP) and collagenated biphasic calcium phosphate (CBCP) loaded with a low dose of recombinant human bone morphogenetic protein-2 (rhBMP-2). Methods: The CBCP was characterized by X-ray diffraction and scanning electron micros¬copy. In rabbit calvaria, four circular 8-mm-diameter defects were created and assigned to one of four groups: (1) blood-filled group (control), (2) rhBMP-2-soaked absorbable colla¬gen sponge (0.05 mg/mL, 0.1 mL; CS group), (3) rhBMP-2-loaded BCP (BCP group), or (4) rhBMP-2-loaded CBCP (CBCP group). The animals were sacrificed either 2 weeks or 8 weeks postoperatively. Histological and histomorphometric analyses were performed. Results: The CBCP showed web-like collagen fibrils on and between particles. Greater di¬mensional stability was observed in the BCP and CBCP groups than in the control and the CS groups at 2 and 8 weeks. The new bone formation was significantly greater in the BCP and CBCP groups than in the control and CS groups at 2 weeks, but did not significantly differ among the four groups at 8 week. The CBCP group exhibited more new bone forma¬tion in the intergranular space and in the center of the defect compared to the BCP group at 2 weeks, but a similar histologic appearance was observed in both groups at 8 weeks. Conclusions: The dose of rhBMP-2 in the present study enhanced bone regeneration in the early healing period when loaded on BCP and CBCP in rabbit calvarial defects.

노인 구강건강증진 사업에 대한 요구도 및 참여 실태: 경기 일부지역

정임희 한국치위생감염관리학회 2018 한국임상치위생학회지 Vol.6 No.1

With the development of medicine and economics, the average life span of individuals in the Korean population has been extended, and the elderly population is rapidly increasing. In such a society, various health problems are emerging in the elderly, and the importance of oral health care services is likewise increasing. However, the existing dental care services offered by the government for the elderly are one-sided approaches; therefore, they are unable to reflect the actual demands of the aging population. The purpose of this study was to investigate the participation status and related requirements of the elderly through an oral health promotion project. In this study, 200 elderly people in Seongnam (Gyeonggi province, Korea) were surveyed. The results showed that most elderly people did not recognize the existence of oral health care services; thus, their participation was very low, and there was a significant variability in the types of health services required among the residential districts (p<0.05). In addition, there was a significant difference in the participation levels in the project according to the residential district unit, sex, and subjective social and economic status (p<0.05). These results indicate that it is necessary to consider these characteristics in promoting participation in future projects.

시판 중인 구강청결티슈의 세포 독성 관찰

정임희,박지현,이민경,황영선 한국치위생과학회 2018 치위생과학회지 Vol.18 No.2

Wet wipes are being increasingly used because of their convenience. Particularly, oral wet wipes are useful for regular cleaning of a baby’s mouth after birth. Therefore, the consumption of oral wet wipes has increased over the past few years and a variety of products are commercially available. However, product information on safety is not sufficiently provided and still raises doubts regarding adverse effects. To confirm the safety of wet wipes as an oral hygiene item and provide information for their use, we investigated the cytotoxicity of oral wet wipes and verified the underlying mechanism. The anti-bacterial effect of oral wet wipes was analyzed using the disk diffusion method. The cytotoxic effects of oral wet wipes were observed based on morphological changes using microscopy and determined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in gingival epithelial cells and gingival fibroblasts. Evaluation of apoptosis by oral wet wipes was explored using propidium iodide flow cytometric analysis and a terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) assay. Apoptosis-related molecules were also analyzed using western blotting. Five types of oral wet wipes were tested, and two products from Fisher-Price and Dr. Kennedy revealed strong cytotoxic effects on gingiva epithelial cells and gingiva fibroblasts, although they also showed intense anti-bacterial effects on oral bacteria. Cell cycle arrest in the G2/M phase and apoptosis were observed based on treatment of extracts from Fisher-Price and Dr. KENNEDY. Relatively high TUNEL levels, reduction of proliferating cell nuclear antigen and cyclin-dependent kinase 4 expression, and fragmentation of poly (ADP-ribose) polymerase were also elucidated. These results suggest that commercial oral wet wipes could exert cytotoxic influences on oral tissue, although there are anti-bacterial effects, and careful attention is required, especially for infants and toddlers.

일부 성인의 민영치과의료보험 가입 여부와 구강건강지식 및 구강건강정보이해력의 관계

정임희(Im-Hee Jung),김민지(Min-Ji Kim) 한국구강보건과학회 2021 한국구강보건과학회지 Vol.9 No.2

Objectives: More and more private dental insurance products are becoming available in Korea, but little is known about how well purchasers of these products understand them. Methods: Some adults conducted a survey to check their oral health knowledge according to whether they joined for private dental health insurance. Results: Adults enrolled in private dental insurance have high levels of knowledge and understanding about oral health. Participants’ knowledge of oral health positively correlated with their understanding of oral health information (r=.408, p<0.01). Conclusions: Education targeted at improving individuals’ understanding of oral health should be strengthened in the future, as patients’ general knowledge of oral health supports the prevention and treatment of oral disease.

인공탈회된 법랑질에 대한 카제인나트륨의 재광화 효과

임희정,정임희,임도선 대한치과위생학회 2022 대한치위생과학회지 Vol.5 No.1

Background: This study aimed to compare the remineralization effects of sodium caseinate and other substances on artificially demineralized enamel. Methods: We selected 25 healthy human premolars and molars and produced a total of 75 specimens by dividing them into five groups: control group, with distilled water; experimental group 1 (EG1), with 3% sodium caseinate; EG2, with 10% sodium caseinate; EG3, with casein phosphopeptide–amorphous calcium phosphate (CPP-ACP); and EG4, with 0.05% NaF. Subsequently, the specimens were immersed in an artificial demineralization solution for 60 min. The demineralized specimens were then immersed in a remineralization solution for 7 days. Surface microhardness was measured using a microhardness tester, and remineralized lesions were observed under a scanning electron microscope (SEM). Regarding statistical analysis, the paired t-test and analysis of variance were performed using the SPSS program. Results: Although the surface hardness of the remineralized lesions increased significantly in all groups (p <0.05), the average increment did not differ significantly between the groups. The surface microhardness of CPP-ACP was the highest, followed by that of 0.05% NaF and 10% sodium caseinate. The remineralization effect of sodium caseinate was similar to that of 0.05% NaF. SEM confirmed that all groups treated with the remineralization solution were remineralized. Conclusions: Although the remineralization effect of sodium caseinate was slightly lower than that of CPP-ACP, it was similar to that of 0.05% NaF. Therefore, to enhance the remineralization effect of sodium caseinate, the appropriate concentration and application time should be determined.

냉장보존 및 냉동보존이 성견 치주인대세포 생존능에 미치는 영향

이동은,정임희,엄유정,정의원,김창성,이승종,최성호 한국생체재료학회 2010 생체재료학회지 Vol.14 No.1

The purpose of this study was to evaluate the effects of cold preservation at 4 C and cryopreservation at -196 C on the viability of periodontal ligament cells in dog teeth using WST-1(4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tet-razolio]-1,3-benzene disulfonate) assay. A total of 7 beagle dogs were used. Eight teeth of each group were divided into 7 experimental groups depending upon the preservation condition. The experimental groups were group 1 (immediate control), group 2-1 (cold preservation at 4 C for 3 days), group 2-2 (cold preservation at 4C for 1 week), group 2-3 (cold preservation at 4C for 2 week), group 3-1 cryopreservation for 3 days), group 3-2 (cryopreservation for 1week), group 3-3 (cryopreservation for 2 weeks). F-medium and 10% dimethylsulfoxide (DMSO) were used as preservation medium and cryoprotectant. For cryopreservation groups, thawing was performed in 37 C water bath, then WST-1 assay was processed. The values of optical density obtained by WST-1 were divided by the values of eosin staining for tissue volume standardization. In WST-1 assay, all cold preservation (4C) groups (group 2, 3, 4) showed significantly higher viability of periodontal ligament cells than cryopreservation group (group 5, 6, 7) (p < 0.05), but showed lower viability than immediate control group (p < 0.05). In cold preservation (4 C) groups, group 2 showed significantly higher viability than group 3 and 4 (p < 0.05). There was no significant difference between all cryopreservation groups (-196 C). From the results of this study, cold preservation method suggests the better efficacy for short term preservation of the teeth than cryopreservation.

Effect of seeding using an avidin-biotin binding system on the attachment of periodontal ligament fibroblasts to nanohydroxyapatite scaffolds: three-dimensional culture

장용주,정임희,박정철,정의원,김창성,이용근,김종관,최성호 대한치주과학회 2011 Journal of Periodontal & Implant Science Vol.41 No.2

Purpose: For periodontal tissue engineering, it is a primary requisite and a challenge to select the optimum types of cells, properties of scaffold, and growth factor combination to reconstruct a specific tissue in its natural form and with the appropriate function. Owing to fundamental disadvantages associated with using a two-dimensional substrate, several methods of seeding cells into three-dimensional scaffolds have been reported and the authors have asserted its usefulness and effectiveness. In this study, we explore the cell attachment of periodontal ligament fibroblasts on nanohydroxyapatite (n-HA) scaffold using avidin biotin binding system (ABBS). Methods: Human periodontal ligament fibroblasts were isolated from the health tooth extracted for the purpose of orthodontic procedure. HA nanoparticles were prepared and Ca(NO₃)₂-4H₂O and (OC₂H_5)₃P were selected as precursors of HA sol. The final scaffold was 8 mm in diameter and 3 mm in height disk with porosity value of 81.55%. 1×10^5 periodontal ligament fibroblasts were applied to each scaffold. The cells were seeded into scaffolds by static, agitating and ABBS seeding method. Results: The number of periodontal ligament fibroblasts attached was greater for ABBS seeding method than for static or agitating method (P<0.05). No meaningful difference has been observed among seeding methods with scanning electron microscopy images. However, increased strength of cell attachment of ABBS could be deduced from the high affinity between avidin and biotin (Kd=10^(-15) M). Conclusions: The high-affinity ABBS enhances the ability of periodontal ligament fibroblasts to attach to three-dimensionally constructed n-HA scaffolds.