• Journal of Korean society of Dental Hygiene
• /
• v.16 no.6
• /
• pp.849-861
• /
• 2016

Objectives: The purpose of the study was to investigate the relationships among snack habits, oral health practice, and oral health status in preschool children. Methods: The subjects were 209 preschool children and their mothers in Jeonbuk from March 24 to May 30, 2014. The study instruments comprised snack habits, oral health practice, and oral health status. Data were analyzed for independent t-test, one way ANOVA and hierarchical multiple regression using SPSS Win 21.0 version. Results: Higher dft index was shown in the older age (p=0.033), lower mother's education (p<0.001), lower mother's daily toothbrushing (p<0.001), check-up after tooth-brushing (p<0.001), tooth-brushing practice before sleeping (p<0.001), tooth-brushing practice after snack (p<0.001), regular dental check-up (p<0.001), fluoride and sealant for prevention caries (p<0.001), limitation of sugar snack intake (p<0.007), periodic replacement toothbrush (p=0.022). The cause of higher dft index included soda (p<0.001), yogurt (p<0.001), snack (p=0.002), bread and cake (p=0.002) and caramel and candy (p<0.001). Fruit (p<0.001), vegetable (p<0.001) and milk (p=0.004) decreased dft index. Factors affecting oral health status were tooth-brushing practice before sleeping, tooth-brushing practice after snack, regular dental check-up, fluoride and sealant for prevention caries, and intake of soda, yogurt, caramel, candy, and fruit. The explanation power of the final model was 67.6%. Conclusions: It is necessary to develop the oral health education program for the preschool children and mothers to enhance the best oral health condition.

• Restorative Dentistry and Endodontics
• /
• v.45 no.2
• /
• pp.22.1-22.10
• /
• 2020

Objectives: This study investigated the influence of glide path size and operating kinetics on the time to reach the working length and the fracture resistance of Twisted File (TF) and Endostar E3 files. Materials and Methods: A total of 120 mandibular single-rooted premolars were selected. Two methods of kinetic motion (TF adaptive and continuous rotary motion) and file systems (TF and Endostar E3) were employed. The files were used in root canals prepared to apical glide path sizes of 15, 20, and 25. The time taken to reach the working length and the number of canals used before the instrument deformed or fractured were noted. Fractured instruments were examined with scanning electron microscopy. Results: The TF system took significantly more time to reach the working length than the Endostar E3 system. Both systems required significantly more time to reach the working length at the size 15 glide path than at sizes 20 and 25. A greater number of TFs than Endostar E3 files exhibited deformation, and a higher incidence of instrument deformation was observed in adaptive than in continuous rotary motion; more deformation was also observed with the size 15 glide path. One TF was fractured while undergoing adaptive motion. Conclusions: No significant difference was observed between continuous rotary and adaptive motion. The TF system and adaptive motion were associated with a higher incidence of deformation and fracture. Apical glide path sizes of 20 and 25 required significantly less time to reach the working length than size 15.

• Restorative Dentistry and Endodontics
• /
• v.39 no.4
• /
• pp.276-281
• /
• 2014

Objectives: The purpose of this study was to compare the cutting efficiency of a newly developed microprojection tip and a diamond-coated tip under two different engine powers. Materials and Methods: The apical 3 mm of each root was resected, and root-end preparation was performed with upward and downward pressure using one of the ultrasonic tips, KIS-1D (Obtura Spartan) or JT-5B (B&L Biotech Ltd.). The ultrasonic engine was set to power-1 or -4. Forty teeth were randomly divided into four groups: K1 (KIS-1D / Power-1), J1 (JT-5B / Power-1), K4 (KIS-1D / Power-4), and J4 (JT-5B / Power-4). The total time required for root-end preparation was recorded. All teeth were resected and the apical parts were evaluated for the number and length of cracks using a confocal scanning micrscope. The size of the root-end cavity and the width of the remaining dentin were recorded. The data were statistically analyzed using two-way analysis of variance and a Mann-Whitney test. Results: There was no significant difference in the time required between the instrument groups, but the power-4 groups showed reduced preparation time for both instrument groups (p < 0.05). The K4 and J4 groups with a power-4 showed a significantly higher crack formation and a longer crack irrespective of the instruments. There was no significant difference in the remaining dentin thickness or any of the parameters after preparation. Conclusions: Ultrasonic tips with microprojections would be an option to substitute for the conventional ultrasonic tips with a diamond coating with the same clinical efficiency.

• Journal of the Korea Convergence Society
• /
• v.9 no.12
• /
• pp.129-135
• /
• 2018

This study aimed to investigate the contamination rate of microorganisms by times after sterilization in mirrors, dental explorers, and pincettes which are the basic tools used in the dental clinic. 60 samples by each tool were used upon packaging them by 10 units. Contamination rate of microorganisms were tested using dry film media(3M Petrifilm Plates) which is a quick check upon collecting 10 samples right after sterilization, at Week 2, 3, 4, 5, and 6. At Week 0 when was right after sterilization, no microorganism was detected in any tools while they were detected in 2 mirrors, 2 dental explorers, and 2 pincettes at Week 6. 2 to 4 colonies on average were detected in mirrors at Week 2 and 4, 1 to 2 colonies in explorers from Week 5, and no colony was found in pincettes until Week 5 but 1 to 2 colonies at Week 6. Based on these results, the needs of effective periods are suggested for the sterilized tools together with their safe usages.

• The Journal of Korean Academy of Prosthodontics
• /
• v.59 no.3
• /
• pp.333-340
• /
• 2021

Although gag reflex is an essential function and a useful physiological defense mechanism, it can become an obstacle in a dental treatment. In this case, a questionnaire was designed and used in consultations to objectify the factors associated with gag reflex. Based on the questionnaire, various treatment protocols were planned, such as behavioral control, which is a systematic desensitization that adapts by placing dental instruments in the oral cavity, and habit control to eliminate vomiting habits after drinking. Except for the placement of the implant fixture under general anesthesia, all restoration procedures were performed in the outpatient clinic in the same manner as the conventional implant fixed prosthetic restoration. The systematic desensitization and behavior technique were repeated until the patient was able to endure discomfort and relieve gag reflex in dental treatment. The patient was successfully received the implant-fixed prosthetic restoration in the partial edentulous region.

• Journal of Oral Medicine and Pain
• /
• v.35 no.3
• /
• pp.177-182
• /
• 2010

Conventional surgical therapy for oral soft tissue includes the use of scalpel, diathermy, cryotherapy and electrosurgery. But, these therapies have some surgical problems. Nowadays, laser surgery can be considered as the another option for conventional surgical therapy. Compared to conventional surgical therapies, advantages of laser therapy include maintenance of sterile conditions, promotion of wound healing, reduction of bleeding, less instruments, post operative pain reduction, less scar, saving cost by using fewer materials, staff and time. Carbon dioxide ($CO_2$) laser uses gaseous medium, and has long wavelength about 10,600nm. The first advantage of $CO_2$ laser for surgical treatment of oral soft tissue is hemostasis and visibility improvement by making relatively dry field. These case reports are about cases of minor surgery of oral soft tissue using $CO_2$ laser, and emphasize advantages of laser compared to conventional surgical therapies.

• Journal of the Korean institute of surface engineering
• /
• v.41 no.4
• /
• pp.147-155
• /
• 2008

The dental orthodontic wire provides a good combination of strength, corrosion resistance and moderate cost. The purpose of this study was to investigate the effects of TiN and ZrN coating on corrosion resistance and physical property of orthodontic wire using various instruments. Wires(round type and rectangular type) were used, respectively, for experiment. Ion plating was carried out for wire using Ti and Zr coating materials with nitrogen gas. Ion plated surface of each specimen was observed with field emission scanning electron microscopy(FE-SEM), energy dispersive X-ray spectroscopy(EDS), atomic force microscopy(AFM), vickers hardness tester, and electrochemical tester. The surface of TiN and ZrN coated wire was more smooth than that of other kinds of non-coated wire. TiN and ZrN coated surface showed higher hardness than that of non-coated surface. The corrosion potential of the TiN coated wire was comparatively high. The current density of TiN coated wire was smaller than that of non-coated wire in 0.9% NaCl solution. Pit nucleated at scratch of wire. The pitting corrosion resistance $|E_{pit}-E_{rep}|$ increased in the order of ZrN coated(300 mV), TiN coated(120 mV) and non-coated wire(0 mV).

• Journal of the korean academy of Pediatric Dentistry
• /
• v.28 no.4
• /
• pp.620-625
• /
• 2001

The pulpectomy or root canal treatment on primary teeth is to be done when there is evidence of chronic in flammation or necrosis in the radicular pulp. Due to the tortuous and ribbon-shaped anatomy of the primary teeth, the instrumentation of endodontic hand files and barbed broaches is not an easy procedure. Recently, many automatic Ni-Ti rotary instruments have been developed and has made endodontic treatment easier and faster. This report describes two cases of root canal treatment on primary molars using Ni-Ti rotary files. The cervical constricture was eliminated by the crown-down method, as smaller file proceeded unhindered into the apical third of the canal. In addition, the crown-down technique enhanced the efficacy of the endodontic irrigant. The use of rotary instrumentation for primary teeth seemed to be a more effective way to debride the uneven walls of primary teeth.

• Korea Journal of Hospital Management
• /
• v.22 no.4
• /
• pp.1-15
• /
• 2017

This study was designed to analyze the effect of servicescape and human service quality on patients' internal response and their behavioral intention in dental care organizations. Self-administered survey questionnaires with structured instruments were developed, and a total of 226 responses were used for statistical analyses using SPSS Windows version 18.0 program and AMOS 18.0 program. Major findings of the study are as follows. First, among other servicescape components, air condition environment was found to have a positive effect on patients' cognitive and physiological responses, while signals and symbols had a positive effect on cognitive and emotional responses. Second, the competence, among other factors of the human service quality, had positive influence on cognitive and emotional responses, while customer understanding affected positively on emotional response. Third, none of the servicescape components showed a direct effect on patients' behavioral intention, but their influence was mediated by internal responses. However, customer understanding, among other human service quality factors, had a direct effect on patients' behavioral intention. Fourth, emotional response, among other internal response factors, proved to have positive influence on behavioral intention. Results from this study suggest that dental care service providers can increase their competitiveness and customer satisfaction by understanding and improving the most important areas of servicescape and human service quality.

• Journal of the Korean institute of surface engineering
• /
• v.43 no.3
• /
• pp.132-141
• /
• 2010

NiTi alloy has been used for orthodontic wire due to good mechanical properties, such as elastic strength and frictional resistance, combined with a high resistance to corrosion. Recently, these wire were coated by polymer and ceramic materials for aesthetics. The purpose of this study was to investigate surface characteristics of polymer coated NiTi alloy wire for orthodontics using various instruments. Wires (round type and rectangular type) were used, respectively, for experiment. Polymer coating was carried out for wire. Specimen was investigated with field emission scanning electron microscopy(FE-SEM), energy dispersive x-ray spectroscopy(EDS) and atomic force microscopy(AFM). The phase transformation of non-coated NiTi wire from martensite to austenite occurred at the range of $14{\sim}15^{\circ}C$, in the case of coated wire, it occurred at the range of $16{\sim}18^{\circ}C$. Polymer coating on NiTi wire surface decreased the surface defects such as scratch which was formed at severe machined surface. From the AFM results, the average surface roughness of non-coated and coated NiTi wire was 13.1 nm, and 224.5 nm, respectively. From convetional surface roughness test, the average surface roughness of non-coated and coated NiTi wire was $0.046{\mu}m$, and $0.718{\mu}m$, respectively.