• Journal of Korean society of Dental Hygiene
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• v.9 no.3
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• pp.282-293
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• 2009

The purpose of this study was to examine the degree of infection control implemented at dental offices and factors affecting it in an attempt to help promote the health of dental health care workers. The subjects in this study were 180 medical personnels who worked at dental offices in the region of South Jeolla Province. A self-administered survey was conducted from April 1 to May 30, 2008, and the collected data were analyzed. The findings of the study were as follows: 1. As for the implementation of infection control at the dental offices, what the health care workers investigated did the most was post-treatment hand washing(95.0), a constant separation of infectious wastes(94.4), wearing rubber gloves all the time during medical instrument cleansing(92.8) and pre-treatment hand washing(91.7). 2. In regard to the implementation of infection control at the dental offices, what the dental personnels did the least was drying their hands with air(5.0), wearing goggles in times of treatment(23.3), receiving regular education on infection control(26.7) and putting sterilizers to a performance test on a regular basis(43.9). 3. The dental health care workers were significantly different according to age in the management of contagious diseases(p=0.005). Their career made a significant difference to the management of contagious diseases(p=0.000) and instrument cleansing/sterilization(p=0.043). The service area made a significant difference to wearing and managing personal protective clothes (p=0.040) and waste management(p=0.040). 4. Concerning the relationship between the acquisition of dental hygienist certificate and the practice of infection control, whether the dental health care workers were certified or not made no significant difference to that. 5. As to the correlation among the factors affecting the prevention and management of contagious diseases, there was a positive correlation among hand washing(r=0.379), wearing and managing personal protective clothes(r=0.349), instrument cleansing/sterilization(r=0.323) and waste management(r=0.388). All the factors made a statistically significant difference to the prevention and management of contagious diseases(p<0.01).

• Journal of Periodontal and Implant Science
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• v.52 no.6
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• pp.437-454
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• 2022

Embryonic stem cells have been a popular research topic in regenerative medicine owing to their pluripotency and applicability. However, due to the difficulty in harvesting them and their low yield efficiency, advanced cell reprogramming technology has been introduced as an alternative. Dental stem cells have entered the spotlight due to their regenerative potential and their ability to be obtained from biological waste generated after dental treatment. Cell reprogramming, a process of reverting mature somatic cells into stem cells, and transdifferentiation, a direct conversion between different cell types without induction of a pluripotent state, have helped overcome the shortcomings of stem cells and raised interest in their regenerative potential. Furthermore, the potential of these cells to return to their original cell types due to their epigenetic memory has reinforced the need to control the epigenetic background for successful management of cellular differentiation. Herein, we discuss all available sources of dental stem cells, the procedures used to obtain these cells, and their ability to differentiate into the desired cells. We also introduce the concepts of cell reprogramming and transdifferentiation in terms of genetics and epigenetics, including DNA methylation, histone modification, and non-coding RNA. Finally, we discuss a novel therapeutic avenue for using dental-derived cells as stem cells, and explain cell reprogramming and transdifferentiation, which are used in regenerative medicine and tissue engineering.

• Journal of Korean society of Dental Hygiene
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• v.16 no.2
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• pp.313-319
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• 2016

Objectives: The objective of the study was to infection control by analyzing the influence of working environment on infection control activities in the dental hygienists. Methods: The cross-sectional study was based on a survey on a total of 377 dental hygienists working in dental settings. Multiple linear regression analysis was performed to examine the relationship of general characteristics and infection control activities. All statistical analyses were performed using the SPSS for Windows version 20.0, and p<0.05 was considered to be significant. Results: Predictive powers(=Adjusted $R^2$ of the investigated factors such as operation room, sterilization disinfection laundry, dental unit waterline, staff individual, infection control system, personal protective equipment, medical waste, hand hygiene, oral surgical procedures, clinical contact surfaces were adjusted $R^2=0.394$, 0.306, 0.277, 0.244, 0.241, 0.177, 0.165,, 0.154, 0.134, 0.124 respectively. Conclusions: In order to enhance infection control activities, the program development and implementation for the aseptic procedure is very important. The program should include periodic reinforcement of infection control education and regular monitoring of infection control activities.

• Journal of Korean Dental Hygiene Science
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• v.3 no.2
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• pp.27-37
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• 2020

This study investigated the relationship between knowledge of COVID-19, the risk of exposure to subjective infectious diseases, and the degree of infection control practices for dental personnel. For dental personnel currently working in dentistry, a survey consisting of 10 questions about COVID-19 knowledge and 63 questions about infection control practices was conducted. This study analyzed 126 survey data collected by distributing questionnaires form May 30 to June 20, 2020. Data was analyzed using t-test, ANOVA, and Pearson correlation. The average level of knowledge of COVID-19 was 5.44 out of 10, the average risk of exposure to infectious diseases was 3.86 out of 5, and the average level of infection control practices was 4.05 out of 5. The risk of exposure to infectious diseases was positively correlated with dental waste (r=.184). It was found that there was a significant positive correlation between infection control practices and sub-factors of infection control practices (p<0.001). To prevent the spread of COVID-19 and infectious diseases and to reduce the risk of exposure to infectious diseases for dental personnel, the practice of infection control should be improved. It is necessary to cultivate infection control experts and have mandatory infection control education and social regulations.

• Journal of Korean society of Dental Hygiene
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• v.7 no.4
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• pp.455-470
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• 2007

The usage of appropriate disinfectants is essential for infection control in dental hospitals, dental clinics. Inadequate use of disinfectants is the cause of human or environmental toxicity and is a waste of cost. This study was aimed to assess the level of knowledge on the disinfection and chemical disinfectants among dental workers in dental hospitals, dental clinics. It's ultimately intended to serve as a basis for the preparation of more effective, appropriate educational programs on the disinfection and manuals on the use of disinfectants for dental workers. This study enforced a questionnaire with 184 dental workers employed in dental hospitals, dental clinics from 15 Aug. to 15 Sep. 2007, in the area of Daejeon. The obtained result were as follows; 1. The population sociological feature of dental hospital and dental clinic showed that significant differences of dental service career(pM0.039). Dental service career of dental workers shows; below 3 years 42.9%, 4~6 years 34.7%, more than 7 years 22.4% in dental hospitals, below 3 years 30.4%, 4~6 years 26.7%, more than 7 years 43.0% in dental clinics(pM0.039). 2. The average score of dental workers knowledge in 'Critical item soaks in high-level disinfectants for 20minutes was 2.73V0.49 point, got from knowledge of dental instrument is appropriate to immerse before sterilization in the dental device disinfection(pM0.002). 3. In the general disinfection which it follows in education experience of chemical disinfectants direction for use, 'Direction for use by Spaulding process classification' responded that the correct answer was the education experience dental workers 60.0%, the education non-experience dental workers 39.5%(p=0.026). 4. In the dental device disinfection which it follows in education experience of chemical disinfectants direction for use. 'High level disinfection is not applied for the non-critical items and equipment' responded that the education experience dental workers 49.2%, the education non-experience dental workers 31.9%(pM0.045), 'Semi-critical items is applied same method in presence of the infection disease which it acts responded that the education experience dental workers 44.6% answer back, the education non-experience dental workers 24.4%(pM0.017). 5. 'A hand disinfectants of anticeptics have effect' the education experience dental workers 78.5% answer back, the education non-experience dental workers 52.9%(pM0.003). 1t uses with hand disinfectants when the instruments which be imbrued and patient contact', the education experience dental workers 78.5% answer back, the education non-experience dental workers 62.2%(pM0.026), 'Boric acid solution uses for the skin disinfectants the education experience dental workers 52.3% answer back, the education non-experience dental workers is 37.0%(pM0.016), 'Gluconate have effective difference which it follows in chemical disinfectant consistency and the solution type' education experience dental workers 72.3% answer back, education non-experience dental workers 47.9%(pM0.004). 6. The education experience dental workers were appeared higher than the education non-experience dental workers in knowledge of the disinfection and chemical disinfectants. Consequently system and the specialty education which is standardized continuously must be provided to all dental workers.

• Journal of dental hygiene science
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• v.22 no.4
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• pp.241-248
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• 2022

Background: Plastic waste generates pollutants in the process of incineration or landfilling, and accumulates in water or marine organisms, causing adverse effects on the environment and the human body. Recently, various eco-friendly oral hygiene products (Eco-OHPs) such as bamboo toothbrushes and biodegradable plastic toothbrushes have been developed. Therefore, this study aimed to investigate the current level of awareness and purchasing status of eco-OHPs among adults who are interested in eco-friendly products. Methods: This study included adults aged >19 years who regularly visited eco-friendly shops and online sites; the online survey links were distributed during their visits to eco-friendly Internet cafés and companies. Of the 22 questions, seven assessed the participants' general characteristics, three assessed the general oral hygiene care products used, six assessed the level of awareness of Eco-OHPs, and six assessed the purchasing status of Eco-OHPs. Frequency analysis, chi-square test, and regression analysis were performed using SPSS software. Results: Among the respondents, 108 (51.4%) were aware of Eco-OHPs, and 79 (37.6%) had experience purchasing Eco-OHPs. The most common reason for not purchasing was the lack of information about related brands or products (74, 56.5%). The most common platform used in obtaining information was the Internet (general: 31.5%, eco-friendly: 46.3%), such as Social Network Service, Internet cafes, and blogs. The experience in purchasing Eco-OHPs was affected by whether the respondents recognized the possibility of contributing to environmental preservation, availability of vendors, product safety, and the number of eco-friendly products purchased. Conclusion: In order to expand the use of Eco-OHPs, various efforts such as promotion of eco-friendly characteristics, determination of related vendors, reliable analysis of product safety, and expansion of product experience opportunities are required.

• Journal of Korean society of Dental Hygiene
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• v.10 no.5
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• pp.935-945
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• 2010

Objectives : The purpose of this study was to examine the knowledge of dental hygienists on infection control in dental office and their attitude toward that in a bid to provide some information on ways of enhancing the level of infection control in dental office. Methods : The subjects in this study were 220 dental hygienists who worked in dental hospitals and clinics in Busan and South Gyeongsang Province. A survey was conducted from May 17 to June 17, 2010, and the answer sheets from 183 respondents were analyzed with a SPSS WIN 12.0 program. Statistical data on frequency, percentage and mean were obtained, and t-test, Pearson correlation coefficient and one-way ANOVA were utilized. Results : They got a mean of $4.59{\pm}.68$ in six categories of infection control knowledge. They had the best knowledge on dental waste disposal, followed by hand washing, post-sterilization management, instrument disinfection and sterilization, surface management of dental equipment and wearing personal protective equipment. They got a mean of $3.99{\pm}.54$ in attitude, and they scored lowest in practice of surface management of dental equipment. Overall, they scored higher in every aspect of knowledge than in attitude(t=11.410, p=.0.000). There was the greatest gap between their knowledge and practice in surface management of dental equipment (t=13.885, p=0.000), and there was the smallest gap between their knowledge and practice in hand washing(t=5.460, p=0.000). And a positive correlation was found between knowledge and attitude, as better knowledge of infection control led to better attitude toward that(p<.001). Finally, concerning infection control knowledge and attitude by general characteristics, the presence or absence of infection control guidelines made differences to infection control knowledge, and infection control attitude was statistically significantly different according to infection control education experiences(t=6.501, p=.012) and the presence or absence of infection control guidelines(t=22.836, p=.000). Conclusions : In order to bolster infection control in dental office, the related system should be improved to legally require dental personnels to implement infection control. Every dental office must be furnished with infection control guidelines, and sustained education should be provided for dental hygienists to carry out infection control.

• Journal of Technologic Dentistry
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• v.35 no.1
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• pp.57-64
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• 2013

Purpose: Waste parts of zirconia blocks and powders were remained after CAD/CAM process. In order to make these residual zirconia fit for practical use, zirconia single cores were produced by drain casting process. Methods: Remained zirconia blocks were reduced to powders with zirconia mortar, and screened with 180 mesh sieve. Zirconia slip was prepared from waste parts of zirconia by ball milling. Plaster molds for forming cores by slip casting were also prepared. Formed cores were removed from mold after partial drying. Dried cores were biscuit fired at $1,100^{\circ}C$ for 1hour. Biscuit fired cores were treated with tools to control the fitness and thickness. Finished cores were $2^{nd}$ fired at $1,500^{\circ}C$ for 1hour. Microstructure of cross section of core was observed by SEM. Results: When mill pot was filled with 100g of zirconia and alumina mixed powder, 300g of zirconia ball, and 180g of distilled water, the optimum slip for drain casting was obtained. Gypsum plaster for ceramic forming was more suitable then yellow stone plaster for casting process. SEM photograph showed the microstructure of fully dense with uniform grain size of zirconia and well dispersed alumina grains into the zirconia matrix. Conclusion: Zirconia single cores were produced by drain casting process. Drain casting is useful process to make these residual zirconia fit for practical use. Further study will be focused on the preparation of the bridge type cores by casting.

• Resources Recycling
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• v.27 no.6
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• pp.38-43
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• 2018

In this study, using electro-refining process and methane gas reduction, we performed studying the recovery of tin with high purity from waste tin oxide had used as a electrode rod of ceramic furnace which occurred during glass production process. We recovered the crude tin of 99% purity from a methane gas reduction process and controlled a little amount of impurities. When the electrolytic refining condition was a current density of $60A/dm^2$ and the sulfuric acid concentration of 0.75 mol, 96.8% of recovered tin (99.979% of purity) were recovered during the electrolytic refining. We confirmed that toxic impurities such as Pb, Sb included in electrode rod. could be controlled.

• The Journal of the Korea Contents Association
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• v.22 no.2
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• pp.370-378
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• 2022

The purpose of this study was to investigate the factors affecting infection control practice by dental hygienist students in Jeju during clinical training amidst the COVID-19 pandemic. Online survey was conducted on 112 students and the results were statistically analyzed with frequency analysis, Student's T-test, one-way ANOVA, and regression analysis using SPSS 20.0. In the 'awareness and practice of infection control by year in college' section, 2nd year students scored significantly higher in 'cleaning and surface disinfection,' 'medical waste disposal,' and 'COVID-19 preventive measure' compared to 3rd year students. In the 'type of training institution' section, hospital setting scored significantly higher in 'cleaning and surface disinfection,' 'instrument disinfection and sterilization,' 'personal and patient protection,' and 'COVID-19 preventive measure' compared to dental clinic setting. In the 'location of institution' section, Seoul metropolitan region scored higher in 'medical waste disposal' compared to Jeju region. According to regression analysis, year in college (2nd year), type of training institution (hospital setting), location of training institution (Seoul metropolitan region), and difficulty using protective gear (no difficulty) were associated with better COVID-19 preventive measure This first study in Jeju provides an insight on the awareness and practice of infection control measures by dental hygienist students in Jeju during clinical training. Further investigation for improvement of clinical training manual is warranted.