• Molecules and Cells
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• v.26 no.5
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• pp.436-442
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• 2008

Osteoclasts are multinucleated cells with the unique ability to resorb bone. Elevated activity of these cells under pathologic conditions leads to the progression of bone erosion that occurs in osteoporosis, periodontal disease, and rheumatoid arthritis. Thus, the regulation of osteoclast apoptosis is important for bone homeostasis. In this study, we examined the effects of the Janus tyrosine kinase 2 specific inhibitor AG490 on osteoclast apoptosis. We found that AG490 greatly inhibited osteoclast apoptosis. AG490 stimulated the phosphorylation of Akt and ERK. Adenovirus-mediated expression of dominant negative (DN)-Akt and DN-Ras in osteoclasts inhibited the survival of osteoclasts despite the presence of AG490. Cytochrome c release during osteoclast apoptosis was inhibited by AG490 treatment, but this effect was inhibited in the presence of LY294002 or U0126. AG490 suppressed the pro-apoptotic proteins Bad and Bim, which was inhibited in osteoclasts infected with DN-Akt and DN-Ras adenovirus. In addition, constitutively active MEK and myristoylated-Akt adenovirus suppressed the cleavage of pro-caspase-9 and -3 and inhibited osteoclast apoptosis induced by etoposide. Taken together, our results suggest that AG490 inhibited cytochrome c release into the cytosol at least partly by inhibiting the pro-apoptotic proteins Bad and Bim, which in turn suppressed caspase-9 and -3 activation, thereby inhibiting osteoclast apoptosis.

• International Journal of Oral Biology
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• v.45 no.3
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• pp.115-125
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• 2020

Resveratrol has been reported to exert anticancer activity via modulation of multiple pathways and genes. In this study, we examined the effect of resveratrol on YD-10B human oral squamous cell carcinoma cells and its molecular mechanisms of action. We found that resveratrol inhibited the proliferation of YD-10B cells in a dose- and time-dependent manner. The suppressive effect of resveratrol was accompanied by a reduction in Bmi-1 gene expression. We observed that silencing the Bmi-1 gene by small interfering RNA effectively downregulated the levels of GLUT1 mRNA and protein, which were also repressed by resveratrol. Bmi-1 silencing increased the number of YD-10B cells in S-phase arrest by approximately 2.3-fold compared with the control. In conclusion, the results of the present study demonstrate, for the first time, that resveratrol suppresses Bmi-1-mediated GLUT1 expression in human oral squamous cell carcinoma cells and suggest that the specific molecular targeting of Bmi-1 and/or GLUT1 expression can be combined with a chemotherapeutic strategy to improve the response of oral cancer cells to resveratrol.

• Journal of Korean society of Dental Hygiene
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• v.17 no.3
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• pp.527-537
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• 2017

Objectives: The purpose of this study was to examine the practice of oral hygiene behaviors and oral health status of long-term care facility residents and to analyze the factors related to salivary hemoglobin level which can predict active periodontal disease. Methods: From 30th October 2015 to 7th January 2016, a questionnaire was provided to 63 participants and their dental plaque and saliva samples were collected to assess the levels of salivary hemoglobin and dental plaque acidogenicity. In order to analyze the factors related to salivary hemoglobin level, multiple linear regression analysis was performed. Results: Toothbrushing was most frequently performed by the participants themselves (98.4%) and toothbrushing was performed after eating breakfast (81.3%). 68.8% of participants reported brushing their tongue. 35.9% of participants perceived having bad teeth, and 87.5% had high dental caries activity. The percentages of participants with hyposalivation and ${\geq}0.20{\mu}g/ml$ salivary hemoglobin level were 45.3% and 59.4%, respectively. The salivary hemoglobin level was significantly higher in the group in which stimulated salivary flow rate was ${\leq}0.70ml/min$, dental plaque acidogenicity was superior, and perceived having bad teeth (p<0.05). There was also a tendency for the salivary hemoglobin level to increase with age (p<0.05). Conclusions: Oral health status of the long-term care facility residents was still not improved, and the characteristics of salivary volume and dental plaque were important factors affecting salivary hemoglobin level. Therefore, it is necessary to operate an oral hygiene intervention program by oral health professionals in such facilities in order to provide residents with effective oral care aligned with their respective needs. Furthermore, it is necessary for caregivers to complete mandatory oral health education to improve the oral hygiene status of the long-term care facility residents.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.203-209
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• 2016

Recently, increased attention has been directed toward medicinal extracts and their active ingredients as potential new drug candidates for androgenic alopecia. Resina Pini (RP), a resinous exudation obtained from Pinus sp. (Pinaceae), has been used as a traditional medicine for the treatment of infection, pain related to dental caries, and periodontal disease. Previously, we suggested that RP and its main constituent, abietic acid (abieta-7,13-dien-18-oic acid; AA), may play important roles against androgenic alopecia as $5{\alpha}$-reductase inhibitors. However, to date, there is no evidence that AA has hair growth-promoting effects in vivo. In this study, we found that 10 ~ 300 mg/kg RP and 3 ~ 30 mg/kg AA significantly promoted hair growth in a C3H/HeN mouse model of alopecia. To our knowledge, this is the first report of the hair growth-promoting effects of RP and AA in vivo. From these results, RP and its main constituent AA can promote hair growth in mouse by inhibiting $5{\alpha}$-reductase activity and may be effective alternative therapies for androgenic alopecia.

• Journal of Korean Academy of Dental Administration
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• v.6 no.1
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• pp.11-18
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• 2018

The aim of this study was to evaluate the competency of the Easyperio test, a genetic test method based on real time PCR for the detection of bacteria that cause dental caries and periodontal disease. To verify the validity of this text, various dental health evaluations were administered to 33 boys between the ages of 12 to 14, as this age group commonly experiences dental caries. These evaluations included a dental caries experience survey, a first molar health evaluation, the Dentocult Streptococcus mutans (SM) strip mutans, the Dentocult Lactobacillus spp (LB) test, and the Easyperio test. The correlation coefficients between the level of the Dentocult SM strip mutans and the dental caries experience were DT (R=0.570, p=0.001), DMFT (R=0.376, p=0.031), and first molar health (R=-0.395, p=0.023). The correlation coefficients between the amount of SM in the Easyperio test and dental caries experience were DT (R=0.528, p=0.002), DMFT (R=0.369, p=0.035), and first molar health (R=-0.426, p=0.013). The correlation coefficients between the level of the dentocult SM strip mutans and the SM amounts of the Easyperio test were S.mi (R=0.564 p=0.001) and S.mu (R=0.621, p=0.002). The correlation coefficients between the level of the Dentocult LB test and the SM amount of Easyperio test was S.mi (R=0.495, p=0.003). In conclusion, Easyperio test may be an easy and effective method for the differentiation and diagnosis of dental caries through quantitative and qualitative analysis of oral bacteria.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.448-468
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• 1996

To maintain its functional integrity, bone is continuously remodelled by a process involving resorption by osteoeclasts and formation by osteoblasts, In order to respond to changes in the physical environment or to trauma with the relevant action, this process is strictly regulated by locally synthesized or systemic fators, Prostaglandin $E_2(PGE_2$) is perhaps one of the best studied factors, having been known to affect bone cell function for several decades.$PGE_2$ has both anabolic and catabolic activities. Excess of $PGE_2$ has been implicated in a number of pathological states associated with bone loss in a number of chronic inflammatory conditions such as periodontal disease and rheumatoid arthritis. $PGE_2$ and other arachidonic acid metabolites have been shown to be potent stimulators of osteoclastic bone resorption in organ culture. The anabolic effects of $PGE_2$ were first noticed when an increase in periosteal woven bone formation was seen after the infusion of $PGE_2$ into infants in order to prevent closure of the ductus arteriosus. The cellular basis for the catabolic actions of $PGE_2$ has been well characterized. $PGE_2$increases osteoclast recruitment in bone marrow cell cultures. Also $PGE_2$ has a direct action on osteoclast serving to inhibit activity and can also indirectly activate osteoclast via other cells in the vicinity, presumably osteoblast. The cellular mechanisms for the anabolic actions of $PGE_2$ are not nearly so well understood. The purpose of this paper was to study the effects of $PGE_2$ and dibutyl(DB)cAMP on osteoblastic clone MC3T3El cells and on the generation of osteoclasts from their precursor cells. The effect of $PGE_2$ and DBcAMP on the induction of alkaline phoaphatase(AlP) was investigated in osteoblastic clone MC3T3El cells cultured in medium containing 0.4% fetal bovine serum. $PGE_2$ and DBcAMP stimulated ALP activity and MTT assay in the cells in a dose-dependent manner at concentrations of lO-SOOng/ml. Cycloheximide, protein synthesis inhibitor, inhibited the stimulative effect of $PGE_2$ and DBcAMP on ALP activity in the cells. $PGE_2$also increased the intracellular cAMP content in a dose-dependent fashion with a maximal effect at 500ng/ml. The effect of $PGE_2$ on the generation of osteoclasts was investigated in a coculture system of mouse bone marrow cells with primary osteoblastic cells cultured in media containing 10% fetal bovine serum.After cultures, staining for tartrate-resistant acid phosphatase(TRAP)-marker enzyme of osteoclast was performed. The TRAP(+) multinucleated cells(MNCs), which have 3 or more nuclei, were counted. More TRAP(+) MNCs were formed in coculture system than in control group. $PGE_2(10^{-5}10^{-6}M)$ stimulated the formation of osteoclast cells from mouse bone marrow cells in culture. $PGE_2(10^{-6}M)$ stimulated the formation of osteoclast cells from mouse bone marrow cells in coculture of osteoblastic clone MC3T3E1 cells This results suggest that $PGE_2$ stimulates the differentiation of osteoblasts and generation of osteoclast, and are involved in bone formation, as well as in bone resorption.

• Korean Journal of Microbiology
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• v.48 no.1
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• pp.52-56
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• 2012

The aim of this study was to evaluate the antimicrobial effect of carvacrol against periodontopathic and cariogenic bacteria and its cytotoxicity in human oral tissue cells. We tested their antibacterial properties against mutans streptococci and five major periodontopathic bacterial species involved in periodontal disease. The antimicrobial activity was evaluated by the minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The cell viability of carvacrol on normal human gingival fibroblast (NHGF) cells was tested by metyl thiazolyl tetrazolium assay. The data showed that carvacrol had remarkable antimicrobial effect on tested bacteria with a MIC and MBC values ranged from 16 to $128{\mu}g/ml$ and from 32 to $128{\mu}g/ml$, respectively. In cell toxicity studies, carvacrol had significantly decreased cell viability when NHGF cells were treated at $128{\mu}g/ml$. These findings suggest that carvacrol has a strong antimicrobial activity against periodontopathic and cariogenic bacteria. However, in order to use it as a component of gargling solution or toothpaste, its concentration should be below $64{\mu}g/ml$ and other compounds having an antimicrobial activity against periodontopathic and cariogenic bacteria should be used together.

• The Journal of the Korean Society for Microbiology
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• v.21 no.4
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• pp.503-513
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• 1986

Previous studies have developed the technique of topical application of tetracycline(TC) into the periodontal pockets and examined the change of clinical parameters and subgingival microbial morphotypes. The purpose of this study was to longitudinally examine the clinical and microbiological effects of topically applied TC in a double-blind and split-mouth design. Thirteen patients with moderate periodontitis, who were treated with or without TC application and scaling treatment, were examined. TC gel(3%) was used to apply into the selected periodontal pockets twice a week for 2 weeks. During the experiment, clinical parameters and subgingival microbial morphotypes were examined, and for isolation of black-pigmented Bacteroides(BPB) and streptococci, an anaerobic sample culturing was done at week 0, 2, and 7. In clinical observation the TC-scaled group exhibited a significant decrease of Gingival Inflammatory Index, Plaque Index, Sulcus Bleeding Index, pocket depth, and gingival crevicular fluid when compared to the TC-unsealed, placebo-scaled, and placebo-unsealed groups. The result of microbial morphotype observation showed a significant increase of coccal form and a decrease of spirochetes in the TC-scaled, TC-unscaled, and placebo-scaled groups. The culture study of streptococci revealed that TC with scaling treatment resulted in a significant increase of S. sanguis I at week 2, but its proportion had returned to the base line level. The anaerobic culture study showed that BPB was significantly reduced in the TC-scaled and TC-unsealed groups at week 7. Among BPB species, B. intermedius declined significantly with time treatment(week 2 and 7) in the TC-scaled and TC-unsealed groups. These results suggest that the settled pathogenic microflora can be succeeded by nonpathogenic microflora in periodontal pockets after TC treatment.

• Journal of dental hygiene science
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• v.2 no.2
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• pp.95-103
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• 2002

This study was carried out to investigate recognition level and practical application status of oral hygiene devices through making a survey of Seoul inhabitants. And survey was implemented in order to propose oral hygiene device for household health care activities. The following results were obtained by analyzing personal interviews of 347 commuting patients at two university hospitals and seven dental clinics. 1) The average length of toothbrush head was estimated as 22.3 mm and average changing cycle was 2.3 months. The user ratio of flat-headed brush was estimated as 51.9% and 46.7% were using fluoridated toothpaste. 2) Generally the ratio of toothpick users was higher than other device users. But the user ratio of dental floss was higher than toothpick in case of patients under orthodontic treatment. 3) The patients under orthodontic treatment were not familiar with handling orthodontic toothbrush. Though 45.8% among orthodontic patients recognized this type of toothbrush, only 25.4% of them knew how exactly to use it. 4) It was shown very low user ratio of oral hygiene devices that the patients who had periodontal problem, hypersensitive trouble, halitosis, implant or denture 5) The patients who had halitosis showed the highest user ratio of toothpick. The patients who had separation of teeth showed the highest user ratio of dental floss. The patients who're under orthodontic treatment showed the highest user ratio of interproximal brush and motorized brush. 6) In response to the most interesting dental disease, it's surveyed as follows; 60.3% of dental caries, 24.0% of periodontal disease, 14.8% of false occlusion and 0.9% of oral cancer. 7) Regarding the motivation of using those oral hygiene devices, 45% responded that it was because of recommendation by dental clinics. Among the negative answers, 38.6% responded that it was because of no selection guidance. 31.3% answered that they didn't use hygiene device because it's inconvenient. 12.0% answered that it's difficult to buy and expensive. 7.8% responded that they didn't feel significant improvement. 4.8% answered that dental hospitals and clinics didn't even introduce those hygiene devices. Therefore efficient campaign for those hygiene devices over all Korea nation should be developed and education program must be prepared for each case of patients in every dental hospitals and clinics.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.557-567
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• 1995

The purpose of this study was to investigated the effect of root planing and decalcified freeze dried allografts on the resorption of transplanted roots and the healing of preveously diseased recipient extraction sockets. The experimental chronic periodontitis was induced by elastic ligatures on the 2nd and 3rd mandibular premolars of 4 adult dogs, and after 8 weeks, crowns were removed and the teeth extracted. The extracted roots were split in half along the long-axis, and the extednt of plaque exposure was morked on the root surfaces with burs. The roots were either root-planed(Test group), or left uninstrumented(Control group), and transplanted in the extraction sockets with decalcified freeze-dried allografts filling the void. The flaps were sutured to cover the sockets completely. The animals were sacrificed after 12 weeks of healing, and the specimens were examined histologically. The results were as follows : 1. No signs of inflammation or disease activity were observed in either groups. 2. Replacement root resorption was observed in both groups. 3. More connective tissue attachments and less ankylosis were observed in the test groups compared to the control. 4. The unresorbed remains of DFDB particles were observed in both groups. 5. DFDB particles in the apical portion of the alveolar sockets were encased in newly-formed bone, while those in the coronal areas were seen encapsulated with connective tissue. 6. No significant difference was found between root-planed and uninstrumented roots relative to the healing and the bone fromation in the recipient extraction sockdets. From the present study, there seemed to be no significant benefits in root planing the transplanted roots or grafting the sockets with DFDB in order to curve the replacement resorption, although the root-planed roots showed more connective tissue attachments. There was also no significant benefits in root transplantation and DFDB for and enhanced healing and bone formation in alveolar extraction sockets.