OBJECTIVES: The purpose of this study was to evaluate abrasion of Icon(R) infiltrated, sound bovine enamel by using confocal laser scanning microscopy (CLSM) after toothbrush abrasion tests. METHODS: Sound bovine enamel specimens whose Vickers Hardness Number ranged from 280 to 320 were prepared. To measure abrasion, specimens were allocated to groups on the basis of tooth brushing stroke frequencies. Tooth brushing stroke frequencies were categorized into 5 groups: 1,800, 5,400, 10,800, 21,600 and 43,200 strokes. Both infiltration depth of Icon(R) and the abrasion depth were measured by CLSM. RESULTS: Mean infiltration depth of Icon(R) for sound bovine enamel was 98.6 microm. There was no statistically significant difference in enamel abrasion depth between groups with 5,400 strokes and 10,800 strokes, but the abrasion depth increased with further increase in tooth brushing stroke frequencies (P<0.001). The mean abrasion depth of resin infiltrated bovine enamel after 43,200 tooth brushing strokes was 17.45 microm. CONCLUSIONS: The magnitude of abrasion after 43,200 tooth brushing strokes, which corresponds to brushing 3 times a day for 4 years, was less than 20 microm. This result suggests that abrasion by tooth brushing would not be a clinical problem for resin infiltrated enamel.
Dental Caries ; Dental Enamel ; Hardness ; Microscopy, Confocal ; Stroke ; Tooth

Background: Although the orofacial-function improvement exercise (OFIE; oral exercise) was first introduced in Korea 10 years prior, it is still not covered by medical insurance, and no detailed survey on the dissemination of related programs has been conducted. Therefore, this study investigated the actual status of the education and practice of OFIE among the elderly and at elderly welfare institutions in the Seoul and Gyeonggi Provinces. Methods: Senior citizens aged more than 65 years old, public health centers (total of 69) and elderly welfare institutions (including nursing homes and elderly welfare centers, total of 56) per administrative area in the Seoul and Gyeonggi Provinces were targeted. We analyzed 200 elderly people and 93 institutions who agreed to participate in the survey. For the elderly, general characteristics, experience and route, current practice, and necessity regarding OFIE were investigated. For institutions, the history and plan of education programs on OFIE were investigated. Results: Regardless of the general characteristics, both the rate of experience and practice for OFIE were low overall; moreover, although they felt it was necessary, they had insufficient motivation for its implementation. Moreover, only a few institutions which were operating the education about OFIE regardless of the COVID-19 situation. Conclusion Although OFIE is necessary for the elderly, its distribution remains insufficient. Therefore, further efforts are needed to expand the education and raise the awareness of oral exercise among elderly individuals and senior welfare institutions.

Background: As a restorative material used to treat dental caries, the light-curing type resin is widely used, but it has the disadvantage of polymerization shrinkage. The Bulk-Fill composite resin was developed to solve these shortcomings, but the existing research mainly focused on comparing the physical properties of a composite resin and a Bulk-Fill resin. A study on the light curing time and distance of the Bulk-Fill resin itself tend to be lacking. Methods: This study compares the surface microhardness of specimens prepared by varying the light curing time and distance of smart dentin replacement (SDR) as a flowable Bulk-Fill resin and Tetric N-ceram as a packable Bulk-Fill resin, and confirms the polymerization time and distance that becomes the optimum hardness. To determine the hardness of the specimen, it was measured using the Vickers Hardness Number (Matsuzawa MMT-X, Japan). Results: In SDR, the surface microhardness decreased as the distance increased in all time groups in the change distance from the curing tip. In the change of light curing time with respect to the distance from curing tip, the surface microhardness increased as the time increased. In Tetric N-ceram, the surface microharness showed no significant difference in the change of the distance of curing tip in the group of 20 and 60 second. But in the group of 10 and 40 seconds, decreased as the distance increased. The surface microharness increased as the light curing time increased in all distance groups. Conclusion When using SDR and Tetric N-ceram in clinical practice, it is considered that as the distance from the polymerization reactor tip increases, a longer light curing time than the polymerization time recommended by the manufacturer is required.

Background: A comprehensive history taking at the first visit could be an important start of treatment. This study investigated the current status of the initial history taking for dental patients in S area, and the implementation and importance of the initial history taking process. Based on this, we intend to provide basic data for the development of organized and standardized questionnaires in dental clinics. Methods: In April 2019, 303 dental clinics in S area were targeted and special dental clinics (orthodontics, children, and disabled) were excluded. The questionnaire consisted of 29 items, including general characteristics, systemic disease history, dental history, oral health behaviors, and the data were obtained through self-administered questionnaire. Results: Initial history taking was mostly implemented using oral and questionnaire at the time of the first visit. Systemic disease history, dental history, and oral health behaviors differed in the work experience of the dental clinic staff. As a result of analyzing the importance according to implementation, there were significant differences in all questions except drug-related items. The importance of the questionnaire was highly recognized, but the reason it was not actually implemented was because of existing the questionnaire in the clinic and lack of time. Conclusion Considering that the initial history taking implementation rate showed low, it is necessary to develop standardize a practical questionnaire and interview skills for dental clinics in the future. In addition, training programs should be provided to dental staff that can recognize the importance of initial history taking questionnaires and contribute to active implementation.

Background: In this study, the bleaching effect and surface damage of two types of over-the-counter home tooth bleaching agents were explored using an in vitro study of bleaching agents applied to bovine teeth specimens for 14 days. Methods: Domestic over-the-counter home tooth bleaching agents of gel and patch form that shared common active ingredients and manufacturers were selected and tested. The experiment specimens were made using composite resin with bovine tooth samples and then measured the initial microhardness. Specimens were then divided into a Gel group and a Patch group and underwent bleaching treatment once a day for two weeks for 30 to 60 minutes (recommended) or 7 hours. All specimens were coffee-stained prior to bleaching. The bleaching effect was measured using a spectrophotometer and surface damage was measured using a microhardness meter. Results: The difference in color following the bleaching procedure was positive in both the Gel and Patch group, although there were no statistically significant differences in bleaching effect between groups. There was no significant difference in bleaching effect based on duration. The microhardness test revealed that both the Gel group and the Patch group had surface damage after bleaching. The greatest surface damage was found in the Patch group that had undergone a 7-hour bleaching treatment, although the differences were not statistically significant. Conclusion The bleaching effect of the home tooth bleaching agent was visible to the naked eye. However, longer applications than recommended did not result in greater bleaching, unlike consumers’ expectations, and instead increased the chance of enamel damage. As such, there is a need for consumers to be alert and adhere to recommendations provided by each company.

Regarding to preserve the cadaver, formaldehyde has been used as a major preservative. However, the usage of formaldehyde has been considered by its harmful effects such as the disturbing ordor, toxicities and limitations to use. Therefore we studied the effect of decomposition-inhibition which is a natural product, grapefruit seed extract (GSE). Concerning the preservative activity, we sacrificed 8 week old male SD rat and collected liver. Using liver tissues, we treated GSE as a time dependant manner under 37degrees, 80+/-5% humidity conditions. To confirm GSE effects, we applied light and electron microscopic analysis. In results, we observed GSE attenuated the morphological changes and putrefaction of liver tissues more than 3 days. Herein, we introduced the potential substitute of formaldehyde to preserve the cadaver as well as animal tissues.
Animals ; Cadaver ; Citrus paradisi ; Electrons ; Formaldehyde ; Humans ; Humidity ; Light ; Liver ; Male ; Rats ; Seeds

IL-12 is a secretory heterodimeric cytokine composed of p35 and p40 subunits. IL-12 p35 and p40 subunits are sometimes produced as monomers or homodimers. IL-12 is also produced as a membrane-bound form in some cases. In this study, we hypothesized that the membrane-bound form of IL-12 subunits may function as a costimulatory signal for selective activation of TAA-specific CTL through direct priming without involving antigen presenting cells and helper T cells. MethA fibrosarcoma cells were transfected with expression vectors of membrane-bound form of IL-12p35 (mbIL-12p35) or IL-12p40 subunit (mbIL-12p40) and were selected under G418-containing medium. The tumor cell clones were analyzed for the expression of mbIL-12p35 or p40 subunit and for their stimulatory effects on macrophages. The responsible T-cell subpopulation for antitumor activity of mbIL-12p35 expressing tumor clone was also analyzed in T cell subset-depleted mice. Expression of transfected membrane-bound form of IL-12 subunits was stable during more than 3 months of in vitro culture, and the chimeric molecules were not released into culture supernatants. Neither the mbIL-12p35-expressing tumor clones nor mbIL-12p40-expressing tumor clones activated macrophages to secrete TNF-alpha. Growth of mbIL-12p35-expressing tumor clones was more accelerated in the CD8+ T cell-depleted mice than in CD4+ T cell-depleted or normal mice. These results suggest that CD8+ T cells could be responsible for the rejection of mbIL-12p35-expressing tumor clone, which may bypass activation of antigen presenting cells and CD4+ helper T cells.
Animals ; Antigen-Presenting Cells ; Clone Cells ; Corynebacterium ; Fibrosarcoma ; Interleukin-12 ; Interleukin-12 Subunit p35 ; Interleukin-12 Subunit p40 ; Macrophages ; Mice ; Rejection (Psychology) ; T-Lymphocytes ; T-Lymphocytes, Helper-Inducer ; Tumor Necrosis Factor-alpha

PURPOSE: This study aims to identify perception, performance, and the related factors of performance in regards to patients' medical information protection among allied health college students. METHODS: Four hundred twelve subjects from three colleges located in Jeonbuk and Kyungbuk province consented to participate. Data was collected from November 28 to December 15, 2012. To assess perception and performance in regards to patients' medical information protection, a self-reporting questionnaire was used. Data was analyzed via SPSS 18.0 program. RESULTS: The score of perception and performance about patients' medical information protection were 4.07 and 3.56, respectively. All item's scores of performance were significantly lower than those of perception. The perception score was significantly different according to recognition of hospital ethics code (t=1.95, p=.052), and recognition of association ethics code (t=2.88, p=.004). The performance score was significantly different according to gender (t=-3.32, p=001), major (F=14.41, p<.001), clinical practicum hospitals (F=8.22, p<.001), and method of electronic medical record access (F=3.23, p=.023). The factors influencing performance were perception(beta=.46, p<.001), duration of clinical practice(beta=-.36, p<.001), and gender(beta=.09, p=.033). CONCLUSION: In order to improve performance in regards to patients' medical information protection of allied health college students, we should develop ethical education programs and standardize them through multidisciplinary collaboration.
Codes of Ethics ; Computer Security* ; Confidentiality ; Cooperative Behavior ; Education ; Electronic Health Records ; Ethics, Institutional ; Humans ; Jeollabuk-do ; Medical Records ; Students, Public Health

This study was undertaken to investigate the morphological changes of hair according to weathering after burial and to offer basic data for forensic science. To examine the effect of weathering degree, the 45 hairs buried for 5~50 years were taken from deceased individuals in tombs in Korea. The morphological changes in weathering hair shafts of the scalp were investigated using the scanning electron microscopes. There were little morphological differences of weathering depending on the regions of burial. The weathering changes includes exclusion of cuticle, separation of hair cortex and hollow formation in the medulla according to the burial period. These results could provide basic data to the field of forensic medicine.
Burial ; Electrons ; Forensic Medicine ; Forensic Sciences ; Hair ; Humans ; Korea ; Scalp ; Weather

This study aimed to evaluate the antimicrobial effects of Acanthopanax sessiliflorum fruit (ASF; Ogaza) extracts on Streptococcus mutans and Streptococcus sobrinus, which are agents that cause dental caries, and on Streptococcus mitis and Streptococcus salivarius, the microbial flora of the oral cavity. The ASF extracts obtained using 70% ethanol were fractionated in the order of ethyl acetate and n-Butanol, concentrated under reduced pressure, and lyophilized to give powdery solvent extracts. The antimicrobial activity of ASF extracts from each solvent was examined using the disk diffusion method. As a result, only those extracts obtained using an ethyl acetate solvent showed antimicrobial activity. These extracts were selected, and the minimum inhibitory concentration was measured by disk diffusion method at various extract concentrations. Results showed a minimum inhibitory concentration of 32 mg/ml. The viable cell count was measured to confirm the minimum bactericidal concentration. Results showed a minimum bactericidal concentration of 64 mg/ml. In the cytotoxicity test using normal human dermal fibroblast cells, the absorbance value of the test group was similar to that of the control group at 0.64, 1.28, and 6.4 mg/ml. The bacteria and their colonies were examined using a scanning electron microscope. Boundaries between the antimicrobial activity region and non-antimicrobial activity region were observed around the paper disk, which was immersed in the extract with 32 mg/ml concentration. Bacterial colonization was not observed in the area with antimicrobial activity. This finding suggests that ASF extracts can inhibit the growth of some microorganisms in the oral cavity, in addition to the effects of these extracts known to date. In particular, ASF extracts may be used as a preparation for preventing dental caries by adding the extract to the toothpaste or oral mouthwash.
1-Butanol ; Bacteria* ; Cell Count ; Colon ; Dental Caries ; Diffusion ; Eleutherococcus* ; Ethanol ; Fibroblasts ; Fruit* ; Humans ; Methods ; Microbial Sensitivity Tests ; Mouth ; Streptococcus ; Streptococcus mitis ; Streptococcus mutans ; Streptococcus sobrinus ; Toothpastes