• Journal of Technologic Dentistry
• /
• v.22 no.1
• /
• pp.145-152
• /
• 2000

In order to select an effective antibiotic substance against oral resident bacteria, we were isolated from soil and texonomically analyzed. Seven hundred and eighteen strains were isolated on humic acid- vitamin agar(HV agar) and 220 strains were on methanol medium from three each paddy forest, field and riverside soil samples. So, during the screening of antibiotics from soil, we isolated microorganisms showing powerful antagonistic activity against oral resident bacteria. Microorganism was tested against 25 strains of bacteria, yeast and fungi. Among them, No. 248 strain exhibited the most strongly growth inhibition. So, the taxonomical analysis the isolated strain was found to be unknown Actinomyces sp. and was named No 248. A production of the antibiotics from No. 248 begins at the early exponential phase developed at the 72th hour under the optinum conditions. The property of No. 248 antimicrobial compound was very stable under acid(pH 3.0) and alkali(pH 10.0) treatment, but it was instable in heat treatment at $120^{\circ}C$. For the improvement of antibiotic activity, two mutants were isolated from strain No. 248 by the treatment of mutagenic agents, NTG and hydroxylamine. As a result, the mutant strains excreted the potent antibiotics to inhibit the growth of Candida albicans.

• Journal of Technologic Dentistry
• /
• v.38 no.3
• /
• pp.135-142
• /
• 2016

Purpose: The aim of this research was to evaluate the influence of different surface treatments on the shear bond strength of zirconia ceramic to composite resin. Methods: Seventy two cylinder-shape (diameter: 5 mm; height: 12 mm) blocks of experimental industrially manufactured Y-TZP ceramic were abraded with $125{\mu}m\;Al_2O_3$ particles and randomly divided into 4 groups. All the materials were categorized as group Gc(control group - composite resin veneering on zirconia surface), Gr - composite resin veneering after surface treatment of Rocatec system (3M ESPE, Seefeld, Germany) group; Gz - composite resin veneering after surface treatment of Zirconia primer (Z-primer, Bisco, U.S.A) group; Gm - composite resin veneering after surface treatment of zirconia primer (Monobond plus, ivoclar vivadent AG, Liechtenstein) group. Two different zirconia primers and Rocatec system were used to zirconia cylinders (n=16) onto the zirconia surface. Zirconia specimens, polished and roughened, were pretreated and composite bilayer cylinders bonded using conventional adhesive techniques. Results: Shear bond strengths were analyzed using single-factor ANOVA(p<0.05). Bond strength values achieved after airbone particle abrasion and zirconia surface pre-treatments(p<0.05). Conclusion: Shear bond strength tests denmonstrated that zirconia primer is a viable method to improved bond strength between zirconia ceramic core and veneering composites.

• Journal of Technologic Dentistry
• /
• v.28 no.1
• /
• pp.27-41
• /
• 2006

The physical property and phase transformation in a commercial dental casting high gold alloy was investigated as a function of ageing temperature and time using microvickers hardness tester, X-ray diffraction, optical and electron microscopy and EPMA analyser. 1. With increasing ageing time, the hardness of solution-treated gold alloys increased slowly at the initial stage of ageing treatment at an ageing temperature of $300{\sim}400^{\circ}C$, and it reached a maximum value of hardness at the medium stage. Finally, it decreased gradually during further ageing. The maximum value of hardness at was similar with that of the conventional materials and suitable for using as the crown & bridge. 2. During isothermal ageing at a temperature range of $300{\sim}400^{\circ}C$, three phases consisting of the Au-rich ${\alpha}_1$phase with a face-centered cubic structure, the Pt3Zn ${\alpha}_2$phase with an ordered AuCu3(L12) type(f.c.c.) and the Pt-rich ${\alpha}_3$phase with face-centered cubic structure in solution-treated gold alloys were transformed into different three phases consisting of the ${\alpha}_1$phase, the ${\alpha}_3$phase and the PtZn $\beta$phase with an ordered AuCu I(L10) type. 3. The hardening of gold alloys was attributed to the lattice strains of the matrix resulting from the transformation of the ${\alpha}_2$phase to the $\beta$phase. 4. The softening of gold alloys during over-ageing was attributed to the coarsening of the nodules consisting of the $\beta$phase and ${\alpha}_1$matrix.

• Journal of The Korean Society of Integrative Medicine
• /
• v.10 no.3
• /
• pp.161-172
• /
• 2022

Purpose : The study was to promote patient safety by analyzing the effect of dental hygienist's perception of patient safety culture on infection control activities. Methods : The study is based on a survey of 210 dental hygienists in total working in dental settings. To find out infection control activities according to patient safety culture awareness, there were 6 general characteristics, 3 teamwork within the department, 2 infection control systems, 4 surface management, 9 equipment washing, disinfection, and laundry management, 4 infectious wastes, and 3 personal protection phrases.The data was analyzed using the SPSS version 20.0, and p<.05 was adopted to decide on significance. Results : The longer dental hygienists have worked n the dental settings, the more active they become in infection control activities. Among the different types of dental care settings, general (university) hospitals had the largest number of infection control activities, followed by dental clinics, and network dental clinics, in descending order. The dental settings possessing a higher number of dental hygienists were found to conduct more infection control activities than other dental settings. In addition, it was found that when a dental setting adopts a patient safety policy across all the units in the hospital, more systems and procedures for patient safety tend to be established, and that stricter management response to error leads to improvement of infection control activities. Conclusion :In order to enhance infection control activities, infection control activity programs should develop and implement periodic reinforcement of infection control education. regular monitoring of infection control activities.

• Journal of Technologic Dentistry
• /
• v.29 no.2
• /
• pp.181-196
• /
• 2007

The purpose of this study is to investigate relations between the organizational culture and job satisfaction of ordinary dental technicians who are serving at dental laboratories. Findings of the study are summarized as follows. Ordinary dental technicians' job satisfaction as a whole was measured 3.40 in average score. In detail, those dental technicians were highest in satisfaction about their work, followed by their work conditions, organizational relations and occupation itself in order, but showed some dissatisfaction in terms of their self-realization. Regarding relations between the organizational culture and job satisfaction of ordinary dental technicians, the former was found significantly affecting the latter. Those dental technicians' job satisfaction was being most positively influenced by innovation-orientation as one of their organizational culture styles, followed by task-orientation. In regard to relations between sub-areas of the satisfaction and styles of the culture, ordinary dental technicians' organizational relations were being significantly, positively affected by such styles of their organizational culture as relation-orientation and task-orientation. Those technicians' occupational satisfaction, self-realization and work conditions were being strongly influenced by one of their organizational culture styles, that is, innovation-orientation. Originary dental technicians' work satisfaction was not being significantly affected by any of the organizational culture styles. The more relation- or task-orienting ordinary dental technicians were in organizational culture, the stronger their organizational relations were. The more innovation-orienting ordinary dental technicians were in organizational culture, the more those dental technicians' satisfaction regarding their occupation, self-realization and work conditions is likely to positively change. These findings indicate that ordinary dental technicians are even more orienting both relation and task in organizational culture, while being afraid of innovation and that their organizational culture as a whole is somewhat strict hierarchically.

• Journal of Technologic Dentistry
• /
• v.35 no.1
• /
• pp.49-56
• /
• 2013

Purpose: The deformation characteristics induced by non-destructive stresses using piezoelectric transducer(PZT) were analyzed for 3-unit fixed partial dentures manufactured PFM, Everest(CAD/CAM) and Zirkonzahn(copy milling, MAD/MAM) by electron speckle pattern interferometery(ESPI). Methods: The ESPI analysis after loading the restoration with PZT by applying electric voltage of 900mV at the points of 10 mm above the base of the prostheses. Results: PFM and All-Ceramic Everest prostheses showed about 0.1 ${\mu}m$ while that of All- Ceramic Zirkonzahn prostheses showed 0.085 ${\mu}m$, demonstrating that Zirkonzahn displaced less. For PFM and All-Ceramic Zirkonzahn prostheses, the displacements were large at just below the loading point, while generalize displacement was shown over the loading point and weak connector areas for All-Ceramic Everest prostheses. Conclusion: We could find that the deformation characteristics induced by non-destructive stresses using PZT analyzed by ESPI were similar to the fracture strengths evaluated using universal testing machine.

• Journal of Technologic Dentistry
• /
• v.32 no.4
• /
• pp.387-401
• /
• 2010

Purpose: The work of Dental technician which is part of national dental health, is more specialized recently. This research provides fundamental data from analyzing student's career consciousness according to needs of a career education. Here is the conclusion of the analysis about student's career consciousness, that is for a right choice of career. Methods: This study did questionnaire to a dental Laboratory Technology student who locate in Taegu. Question response student number was 570 people. Response contents analyzed to 506 people except imperfect questionnaire. Data used windows sas 8.0 program and did descriptive statistical analysis. Results: There is a meaningful difference in what they want to know about an occupation according to ages. (${\rho}$ < 0.01) All ages are similar to their occupational thinking, however they who are under twenties consider working environment. Most motives of an entrance are similar, there is a meaningful difference. (${\rho}$ < 0.05) According to a grade of college, there is a meaningful difference how to obtain informations of a career. (${\rho}$ < 0.05) Sophomores and juniors obtain information from seniors or family, however freshmen obtain from the internet because of an accessibility. There is a meaningful difference of a job meaning between men and women. (${\rho}$ < 0.01) Men are working for a means of living. But women give weight to a self-development. The older they grow, the more they know about their aptitude. Selecting subjects are different choosing time & motive. According to ages and where they are from, there is a meaningful difference how much know about their aptitude. (${\rho}$ < 0.05) Older Students know more than young students. Selecting subjects are different choosing time & motive. In accordance with a grade, ages, and where they are from, there are different degrees about how much know their interests. There is a meaningful difference of a choosing major period and choosing informations. (${\rho}$ < 0.01) And also there is a meaningful difference where they are from and why they enter to College. (${\rho}$ < 0.001) In accordance with a grade, ages, and where they are from, there are different degrees about how much know their aptitude. There is a meaningful difference of a choosing major period. (${\rho}$ < 0.01) And also there is a meaningful difference why they enter to College. (${\rho}$ < 0.001) Conclusion: Although we know that a career education is very important, however lots of students select a career without their aptitude & interest & character. We need to teach a career education systematically; considering students career consciousness, with a proper career guidance, cultivating career consciousness.

• Journal of Technologic Dentistry
• /
• v.42 no.2
• /
• pp.173-185
• /
• 2020

Purpose: The purpose of this study was to investigate dental technicians' awareness of infections and to enhance their interest and commitment towards infection prevention. Methods: A self-reported questionnaire survey was conducted among dental technicians. Total of 195 responses were used for analysis. A cross-tabulation analysis was used to compare dental technicians' awareness of infections according to their levels of education on infection prevention (α=0.05). Results: Dental technicians were educated on infection prevention (40.5%). Most participants received infection prevention education from school (29.8%). Dental laboratories had an infection control guideline (34.9%). Dental technicians were not aware of infection risks at their workplaces or believed that they were not at risk of infections at their workplaces (59.3%). Conclusion: Dental technicians must be consistently educated on infection prevention and control through systematic education at school and wider promotion through media. Research is needed to economically and efficiently improve equipment used by dental technicians and to protect them from infectious diseases. A budget for infection prevention must also be determined. Institutional measures such as providing support for dental technicians at the policy level and developing a basic infection prevention manual are necessary. Solving these issues not only protects dental technicians from infections but also allows them to provide high-quality medical services.

• 대한예방의학회:학술대회논문집
• /
• 2000.10a
• /
• pp.308-309
• /
• 2000

• 대한예방의학회:학술대회논문집
• /
• 2000.10a
• /
• pp.266-267
• /
• 2000