• Journal of Korean society of Dental Hygiene
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• v.5 no.2
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• pp.263-278
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• 2005

This study investigated the current oral health conditions of the elderly at home and welfare facilities in their age over 65 years around some rural areas in Gangwon province, which would expect the fewer medical benefits even with lower interest than urban areas, despite of relatively high ratio of elder populations, so that it could prepare a basic document necessary to determine certain planned quantification for the benefit of elder's oral healthcare. As of the end of December 2004 both 50 elders at home and 50 elders at welfare facilities were randomly sampled in their age over 65 years in Samcheok city. As a result of this study, it was found that the elders at welfare facilities scored 15 pts. in DMFT index level typical of oral health conditions, which was higher than the elders at home. In addition, the elders at welfare facilities scored 26.0% in the coexistence of immobile bridge and partial denture higher than the elders at home with regard to the presence of intraoral prosthetic appliance. The results of analyzing the difference in the one-year dental visiting experience of respondents hereof showed that the elders at home were relatively more in ratio(62.0%) than those at welfare facilities, while many of the former group(38.0%) had relatively more handicap in masticatory movement than the latter one with regard to the conditions of dental prosthesis in use. Besides, many of the elders at facilities(30% or more) felt subjective symptoms of periodontal disease including bleeding or swelling, which indicates higher ratio than the elders at home. Finally, the elders at home used to brush their teeth at more frequency on a daily basis than those at facilities, while the latter group suffered general body disease more than the former group. Summing up, it is concluded that a formulated oral healthcare system will become more needed in near future than now for the benefit of the elderly living in welfare facilities, while nationwide policy-level supports would be urgent for them in the aspect of national welfare.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.5
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• pp.289-295
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• 2006

Sodium fluoride (NaF) has been shown to be cytotoxic and elicit inflammatory response in human. However, the cellular mechanisms underlying NaF-induced cytotoxicity in periodontal tissues have not yet been elucidated. This study is aimed to investigate the mechanisms of NaF-induced apoptosis in human gingival fibroblast (HGF). NaF decreased the cell viability of HGF in a dose- and time-dependent manner. NaF gave rise to apoptotic morphological changes including cell shrinkage, chromatin condensation, and DNA fragmentation. However, NaF did not affect the production of ROS. In addition, NaF augumented cytochrome c release from mitochondria into the cytosol, and enhanced caspase -9 and -3 activities., cleavage (85 kDa fragments) of poly (ADP-ribose) polymerase (PARP) and upregulation of voltage-dependent anion channel (VDAC) 1. These results demonstrated that NaF-induced apoptosis in HGF may be mediated with mitochondria. Furthermore, NaF elevated caspase-8 activity and upregulated Fas-ligand (Fas-L), suggesting involvement of death receptor mediated pathway in NaF-induced apoptosis. Expression of Bcl-2, an anti-apoptotic Bcl-2 family, was downregulated, whereas expression of Bax, a pro-apoptotic Bcl-2 family, was not affected in NaF-treated HGF. These results suggest that NaF induces apoptosis in HGF through both mitochondria- and death receptor-mediated pathway mediated by Bcl-2 family.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.432-461
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• 1995

The basic principles in the design of Class II amalgam cavity preparations have been modified but not changed in essence over the last 90 years. The early essential principle was "extension for prevention". Most of the modifications have served to reduce the extent of preparation and, thus, increase the conservation of sound tooth structure. A more recent concept relating to conservative Class II cavity preparations involves elimination of occlusal preparation if no carious lesion exists in this area. To evaluate the ideal ClassII cavity preparation design, if carious lesion exists only in the interproximal area, three cavity design conditions were studied: Rodda's conventional cavity, simple proximal box cavity and proximal box cavity with retention grooves. In this study, MO amalgam cavity was prepared on maxillary first premolar. Three dimensional finite element models were made by serial photographic method. Linear, eight and six-nodal, isoparametric brick elements were used for the three dimensional finite element model. The periodontal ligament and alveolar bone surrounding the tooth were excluded in these models. Three types model(B option, Gap option and R option model) were developed. B option model was assumed perfect bonding between the restoration and cavty wall. Gap option model(Gap distance: $2{\mu}m$) was assumed the possibility of play at the interface simulated the lack of real bonding between the amalgam and cavity wall (enamel and dentin). R option model was assumed non-connection between the restoration and cavty wall. A load of 500N was applied vertically at the first node from the lingual slope of the buccal cusp tip. This study analysed the displacement, 1 and 2 direction normal stress and strain with FEM software ABAQUS Version 5.2 and hardware IRIS 4D/310 VGX Work-station. The results were as followed. 1. Rodda's cavity form model showed greater amount of displacement with other two models. 2. The stress and strain were increased on the distal marginal ridge and buccopulpal line angle in Rodda's cavity form model. 3. The stress and strain were increased on the central groove and a part of distal marginal ridge in simple proximal box model and proximal box model with retention grooves. 4. With Gap option, Rodda's cavity form model showed the greatest amount of the stress on distal marginal ridge followed by proximal box model with retention grooves and simple proximal box model in descending order. 5. With Gap option, simple proximal box model showed greater amount of stress on the central groove with proximal box model with retention grooves. 6. Retention grooves in the proximal box played the role of supporting the restorations opposing to loads.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2459-2467
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• 2010

The purpose of this study was to survey visiting health care personnel who worked for their public medical health institutions and thereby investigate their oral health knowledge and behavior. Findings of this study are summarized as follow; First, our visiting health care personnel had a significant tendency toward higher score at correct answers to questions about oral health knowledge (mean knowledge about periodontal disease: 67%, mean knowledge about dental caries: 68%, mean knowledge about common dentistry: 68.4% or higher). Secondly, in terms of oral health care behavior, 50% or higher of all our visiting health care personnel visited dental clinic for preventive purposes, and 60.1% visited dental clinic for oral treatment. 46.6% of health care personnel relied on dental clinic for regular scaling services, and 89.6% relied on general hospital or dental clinic for oral treatment. 89.5% of health care personnel brushed their teeth 3 times or more per day; more than half (58%) of them preferred dental floss to other oral hygiene supplies; and 46% practiced roll technique to brush their teeth. Thirdly, health care personnel's oral health knowledge was significantly correlated with their age (F=5.25, p<0.01) and career of health care (F=3.94, p<0.01), while their oral health behavior was significantly associated with their career of visiting health care (F=3.20, p< 0.05).

• Restorative Dentistry and Endodontics
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• v.17 no.1
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• pp.104-114
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• 1992

The purpose of this study was to evaluate the shear bond strength of glass ionomer cement(Ketacfil, ESPE, Co.) against dentin surface which had been treated with surface conditioning agents(distilled water, 5% sodium hypochlorite solution, Ketac - conditioner, 40% polyacrylic acid). In this study, 60 human molars with sound and healthy crown portion which were previously extracted for orthodontic or periodontal problem. The dentin surfaces of these teeth were exposed with wet trimmer and polished with 150 - grit and 600 - grit silicon carbide paper and the teeth were divided into four groups(15 teeth per group) according to the following surface conditioning methods. Group I : Surface treatment with distilled water as control group. Group II : Surface conditioning with 5% sodium hypochlorite solution. Group III : Surface conditioning with Ketac conditioner. Group IV : Surface conditioning with 40% polyacrylic acid. The shear bond strengths were measured by Autograph(Shimatzu Co. Japan). The result of the evaluations were then subjected to statistical analysis using one - way analysis of variance and Duncan test and the results were as follows : 1. The shear bond strength accrding to the dentin surface conditioning conditions was highest in Ketac conditioner group, with measurements of $44.44{\pm}0.74(kg/cm^2)$ and lowest in the distilled water group, with measurements of $28.84{\pm}0.88(kg/cm^2)$. 2. Statistically significant differences were found between surface conditioning with 5% sodium hypochlorite solution group or Ketac conditioner group and distilled water group(P<0.01). 3. Also, statistically significant difference was found between surface conditioning with distilled water group and 40% polyacrylic acid group(P<0.05). 4. Overall difference in statistical significance between the groups was not found (P<0.05). 5. Fractured dentin surface treated with conditioning solutions showed cohesive fracture. 6. Distilled water group and 5% sodium hypochlorite solution group removed the smear layer less effectively. 7. Conditioning dentin with Ketac conditioner and 40% polyacrylic acid resulted in the removal of a significant amount of the smear layer without removing the tubular plugs and dissolving the peritubular dentin.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.197-212
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• 1998

The purpose of this study was to evaluate the effects of fluoride application on the aspect of shear bond strength of three aesthetic restorative materials to dentin. One light-cured composite resin(Palfique Esterite) and two light-cured glass ionomer cements(Fuji II LC and Compoglass)were used in this study. 120 permanent molars were used for this study. The teeth were extracted due to the origin of periodontal disease. The crowns of all teeth were removed, and the remaining roots were embedded in epoxy resin. The mesial or distal surfaces of roots were ground flat to expose dentin and polished on wet 320-, 400-, and 600 grit SIC papers for a total of 120 prepared flat root dentin surfaces. The prepared samples were divided into six groups. Group 1, 3, and 5 were control groups and group 2, 4, and 6 were experimental groups. Sixty samples for experimental groups were treated with 2% NaF solution for 5 minutes. Group 1 and 2 were bonded with Plafique Esterite, group 3 and 4 were bonded with Fuji II LC, and group 5 and 6 were bonded with Compoglass. After 24 hours water storage at $37{\pm}1^{\circ}C$, all samples were subjected to a shear to fracture with Instron universal testing machine(No.4467) at 1.0 mm/min displacement rate. Dentin surfaces treated with each conditioners before bonding and interfacial layers between dentin and aesthetic restorative materials were observed under Scanning Electron Microscope(Hitachi S-2300) at 20Kvp. The data were evaluated statistically at the 95% confidence level with ANOVA test. The result were as follows; 1. Among the control groups, group 1 showed strongest bond strength and group 3 showed weakest. 2. Among the experimental groups, group 2 showed strongest bond strength and group 6 showed weakest. 3. Statistical analysis of the data showed that pretreatment of dentin with 2% NaF solution significantly decreased the bond strength of three aesthetic restorative materials to dentin(P<0.05). 4. SEM findings of fluoride treated dentin surfaces (2, 4, 6 group) demonstrated dentin surfaces covered with fluoridated reaction products. 5. Except group 4 and 6, resin tags were formed in all groups.

• Journal of Oral Medicine and Pain
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• v.34 no.2
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• pp.153-167
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• 2009

The present study was performed to observe the effect of phytoncide on oral normal microflora and the inhibitory effect of the surviving resident oral bacteria on Pr. intermedia. In this study, saliva from each of 20 healthy subjects was treated with 1% phytoncide from Japanese Hinoki (Chamaecyparis obtusa Sieb. et Zucc.). Surviving salivary bacteria were isolated on blood agar plates and identified by 16S rDNA sequencing. In order to select inhibitory isolates against Pr. intermedia, the isolates from the phytoncide-treated saliva were cultured with Pr. intermedia. The results were as follows: 1. Among the 200 surviving resident oral bacterium, 148(74.0%) bacterium inhibit the growth of Pr. intermedia on blood agar plates. 2. The 200 surviving resident oral bacterium were 109 Streptococcus salivarius(54.5%), 25 Streptococcus sanguinis(12.5%), 15 Streptococcus mitis(7.5%). 3. Among the 148 bacteria which inhibit Pr. intermedia, Streptococcus salivarius was 85.3%(93/109), Streptococcus sanguinis was 64.0%.(16/25), Streptococcus mitis was 54.3%(8/15), Streptococcus parasanguinis was 66.7%(6/9), and Streptococcus Alactolyticus was 100%(8/8). Taken together, among the surviving resident oral bacterium, Streptococcus salivarius, Streptococcus sanguinis, Streptococcus mitis were mainly observed to inhibit Pr. intermedia. and they may exert an additional inhibitory activity against the periodontopathic bacterium. Therefore, phytoncide can be used for preventing and ceasing the progress of periodontal disease and halitosis, and thus is expect to promote oral health.

• Journal of Oral Medicine and Pain
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• v.34 no.2
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• pp.123-132
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• 2009

Purpose : To investigate the actual conditions of diagnosis and treatment of oral medicine inpatient with systemic disease. Methods : A total of 54 oral medicine subjects, inpatient due to systemic disease for diagnosis and treatment of oral disease was requested to answer the medical history and dental treatment record. Results : The ratio of gender is composed of male 44% and female 56%, the distribution of age is the order of the 50-59 group 37%, the 60-69 group 26%, the 40-49 group 22%. Systemic disease is composed of Endocrine, nutritional and metabolic diseases 36%, Diseases of the circulatory system 36%, Diseases of the nervous system 10%. Chief complain of oral disease is composed of routine check for oral health 26%, craniomandibular disorders 18%, soft tissue problem 18%. Oral disease is composed of Diseases of salivary glands 32%, Gingivitis and periodontal diseases 23%, Dentofacial anomalies 16% Conclusion : These findings indicate that oral medicine inpatient due to the systemic disease is significantly correlated to the oral disease. The patients of oral disease interrelationship between inpatient and outpatient of systemic disease should be validated by future research.

• Journal of dental hygiene science
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• v.16 no.2
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• pp.127-133
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• 2016

The aim of this study was to examine the geriatric status, oral health, and oral health related quality of life of stroke patients hospitalized at a rehabilitatio ward and assess the relationships among these factors. A total of 78 stroke patients participated in this cross-sectional study. The following oral examinations were performed by a dentist and dental hygienist: Decayed, Missing, Filled Teeth, gingival, debris, calculus, and community periodontal index (CPI). The patients' sociodemographic and geriatric status were evaluated using the Barthel index and a mini-mental state examine (MMSE) according to their medical record and a questionnaire survey. Oral health related quality of life was assessed using the Oral Health Impact Profile (OHIP)-14 questionnaire. Except for three participants, most stroke patients had a gingival index of 2 or more, which means probing results in bleeding gums. Additionally, 53.8% of participants had a CPI code of 3 or 4, which indicates a probing depth of 4 mm or more. CPI index was significantly related to debris, calculus, and gingival index. The OHIP-14 score significantly related to the Barthel index and MMSE (p<0.05). The oral health of stroke patients in the rehabilitation ward was relatively poor and related to poor oral hygiene. Oral health related quality of life was related not to oral health but to geriatric status significantly.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.98-105
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• 2015

We investigated the effects of a mutan (water-insoluble ${\alpha}$-glucans) isolated from Streptococcus mutans on the healing of bone defect in rat. Sprague-Dawley rats were divided into control (saline-treated), lipopolysaccharide (LPS)-treated, and mutan-treated groups (n=6 per group). Experimental bone defects were surgically created with round fissure bur at the buccal surface of the left mandibular. The control groups was administered with saline solution (0.1 ml/100 g), while the LPS and mutan group was given LPS and mutan (1 mg/kg body weight) three times weekly. After 4 weeks the rats were sacrificed, the healing of bone defect was assessed by bone mineral density (BMD) and micro-computed tomography (${\mu}CT$) examination. Percent bone volume (bone volume/tissue volume [BV/TV]), trabecular thickness (Tb.Th), and trabecular number (Tb.N) parameters of ${\mu}CT$ showed higher values in control group than LPS and mutan group. Bone surface/volume ratio (BS/BV), trabecular bone pattern factor (Tb.Pf), and structure model index parameters of ${\mu}CT$ showed higher values in LPS group than mutan group. BMD values of mutan treated-alveolar bones were significantly lower for than that of the LPS group. Therefore, we suggest that mutan, water-insoluble ${\alpha}$-glucans from S. mutans may be induce the induction of periodontal diseases.