• Corrosion Science and Technology
• /
• v.8 no.2
• /
• pp.89-92
• /
• 2009

Pure Ti as well as Ti-6Al-4V alloy exhibit excellent properties for dental implant applications. However, for a better biocompatibility it seems important to avoid in the composition the presence of V due to the toxic effects of V ion release. Thus Al and V free and composed of non-toxic element such as Nb, Zr alloys as biomaterials have been developed. Especially, Zr contains to same family in periodic table as Ti. The addition of Zr to Ti alloy has an excellent mechanical properties, good corrosion resistance, and biocompatibility. In this study, the electrochemical characteristics of Ti-Zr alloys for biomaterials have been investigated using by electrochemical methods. Methods: Ti-Zr(10, 20, 30 and 40 wt%) alloys were prepared by arc melting and homogenized for 24 hr at $1000^{\circ}C$ in argon atmosphere. Phase constitutions and microstructure of the specimens were characterized by XRD, OM and SEM. The corrosion properties of the specimens were examined through potentiodynamic test (potential range of -1500 ~ 2000 mV), potentiostatic test (const. potential of 300 mV) in artificial saliva solution by potentiostat (EG&G Co, PARSTAT 2273. USA).

• The Journal of Advanced Prosthodontics
• /
• v.9 no.2
• /
• pp.99-103
• /
• 2017

PURPOSE. The purpose of this study was to achieve more retention and stability and to delay or prevent screw loosening. MATERIALS AND METHODS. Twenty implants (Implantium 3.4 mm, Dentium, Seoul, Korea) were divided into 2 groups (n = 20). In the first group, an adhesive material was applied around the screw of the abutments (test group). In the second group, the screws are soaked in saliva (control group). All the screws were torqued under 30 N/cm, Then, the samples were gone through a cyclic fatigue loading process. After cyclic loading, we detorqued screws and calculated detorque value. RESULTS. In comparison with the control group, all the implant screws in the test group were smeared with the adhesive material, showing significant higher detorque value. CONCLUSION. There are significantly higher detorque values in the group with adhesive. It is recommended to make biocompatible adhesive to reduce screw loosening.

• Journal of Korean Clinical Nursing Research
• /
• v.14 no.3
• /
• pp.15-25
• /
• 2008

Purpose: This study was aimed to investigate the effects of gum-chewing on the recovery of bowel movement and oral cavity discomfort after abdominal surgery. Method: The nonequivalent control group, non-syncronized repeated treatment design was used. A total of 99 patients were participated in the study. The 44 patients were in the experimental group and the rest in the control group. The experimental group chewed gum three times a day until they passed gas. As the patient reported gas-passing, bowel movement time, subjective symptoms of oral cavity, and oral status were recorded precisely. The frequency, percentage, $x^2$-test and t-test were analyzed by SPSS PC 12.0. Results: There were significant differences in bowel movement, gas passing, oral cavity symptoms, and oral status scores between the experimental and the control group. Conclusion: The findings of the study demonstrated the fact that gum-chewing helps early recovery from post-operative ileus and thirst. It is because gum chewing stimulates bowel mobility and secretion of saliva. Thus gum-chewing seems to be an effective nursing intervention in reducing post-operative side effects for patients with abdominal surgery.

• Asian Oncology Nursing
• /
• v.7 no.1
• /
• pp.68-78
• /
• 2007

Purpose: The purpose of this study was to examine the effects of cold oral gargling on oral discomfort among Non-Hodgkin's lymphoma patient undergoing chemotherapy. Method: An quasi-experimental, nonequivalent control group design was used. Thirty two patients receiving chemotherapy at G hospital in P city were recruited from August 1, 2002 to October 20, 2002. Sixteen were conveniently allocated into the experimental group and 16 into the control group. Participants in the experimental group used cold oral gargling while their counterparts used room temperature oral gargling. Subjective and objective oral discomforts were measured by the instruments developed by Beck. The SPSS WIN 10.0 program was used to analyze the data with t-test, ${\chi}^2$ -test, and repeated measures ANOVA. Findings: The participants in the experimental group reported less oral discomfort and showed better oral conditions than those in the control group at the post 7th, 14th, and 21st days. Participants in the experimental group reported better oral conditions in taste, tongue, eating, and saliva than those in the control group. Conclusion: The cold oral gargling seemed to be more beneficial than room-temperature oral gargling in reducing oral discomfort for the Non-Hodgkin's lymphoma patients undergoing chemotherapy.

• Journal of the Korea Furniture Society
• /
• v.21 no.3
• /
• pp.261-272
• /
• 2010

The aim of the present study was to investigate the relations between wooden toy and development of infant and young children by taking only the commercialized wooden furniture which would be suitable for the developmental area for infant and young children, among the physical environment influencing the balanced development and development for them. The recommended standard for them was the commercialized good and the only advanced toys for the development of infant and young children was primary selected, in case of different furniture for same purpose with regardless of manufacturer, country of origin and price. The selected wooden toys for development of infant and young children covered the following test conditions. They keep the soft and clean surfaces and the corners are the round-finished so safe. The dyeing and coloring are so clear like the rainbow-colored in compliance with the international safety norm, and the paint material used are harmless to the people, because they have already passed the European Safety Norm EN 71 which is the most authoritative and strict standard in the world and contained accordingly little heavy metals, toxic substances and also allergy pigment under the maximum permissible standard. The size of wooden toys are not small enough for infant and young children to be able to swallow and this is important check point, because infants tend to feel the object in their own touching and therefore to have everything to the lip. The paint used was the toys-oriented goods and proved by the test regarding saliva and sweat.

• Parasites, Hosts and Diseases
• /
• v.54 no.5
• /
• pp.605-616
• /
• 2016

In the present study, quids from La Cueva de los Muertos Chiquitos (CMC) were subjected to ELISA tests for 2 protozoan parasites, Toxoplasma gondii (n=45) and Trypanosoma cruzi (n=43). The people who occupied CMC, the Loma San Gabriel, lived throughout much of present-day Durango and Zacatecas in Mexico. The known pathoecology of these people puts them into at-risk categories for the transmission of T. gondii and T. cruzi. Human antibodies created in response to these 2 parasites can be detected in modern saliva using ELISA kits intended for use with human serum. For these reasons, quids were reconstituted and subjected to ELISA testing. All test wells yielded negative results. These results could be a factor of improper methods because there is no precedence for this work in the existing literature. The results could equally be a simple matter of parasite absence among those people who occupied CMC. A final consideration is the taphonomy of human antibodies and whether or not ELISA is a sufficient method for recovering antibodies from archaeological contexts. An additional ELISA test targeting secretory IgA (sIgA) was conducted to further examine the failure to detect parasite-induced antibodies from quids. Herein, the methods used for quid preparation and ELISA procedures are described so that they can be further developed by future researchers. The results are discussed in light of the potential future of quid analysis.

• Journal of Oral Medicine and Pain
• /
• v.31 no.1
• /
• pp.79-89
• /
• 2006

The aim of this study is to know how the rat submandibular gland changes under various emotional stress condition, using molecular biological methods. Restraint and chronic unpredictable mild stress (CUMS) experiment is conducted on fifty one 7-week old Sprague-Dawley rats (restraint stress experiment: 21, CUMS: 30). The rats were sacrificed, the submandibular glands were excised immediately at certain time, and examined by the use of immunohistochemistry and western blotting. In CUMS experiment, sucrose preference test, water intake change, weight change were implemented at 1 week interval for the experimental period The results are as follows: 1. The number of clusterin-secreting cells of restraint stress group compared to control group showed significantly decreasing tendency in all experimental groups except for the 1st hour group (p<0.001 in the 9th, 24th, 72nd, 120th, and 168th hour group). 2. The number of clusterin-secreting cells of CUMS group compared to control group showed significantly increasing tendency in the 2nd week group (p<0.01), and significantly decreasing tendency in the 4th and 5th week group (p<0.001). 3. Sucrose preference test in CUMS experiment showed significant difference between the 5th week experimental group and control group (p<0.01). 4. Weight change in CUMS experiment showed significant difference between the 5th week experimental group and control group (p<0.01), but water intake change didn't show significant difference compared to control group. 5. In western blot analysis, clusterin expression was decreased on a gradual basis in due time compared to the control group in the restraint stress group. As for CUMS group (chronic unpredictable mild stress group), it was increased till the 2nd week and decreased till the 5th week after that, which is similar to immunohistochemical analysis result and the decreasing tendency of sucrose preference and weigh changes. Through the test, it was proved that expression of clusterin in saliva glands decreases after receiving either acute or chronic stress, indicating relation with depression caused by chronic stress. Unlike other data, however, apoptotic tendency was hardly found in tissues. Diverse possibilities could be suggested on that: first, the stress was not enough to expedite apoptosis; second, apoptosis-related protein was already being secreted though not detected with microscope; third, clusterin, a major secretion molecule of saliva, decreased with saliva's malfunction due to stress. In the respect, it will be necessary to examine proteins expressed in case of cell death or other heat-shock proteins at the same time, in order to see whether any cellular change or death is caused by decreasing clusterin under high stress, and whether the original state is restored as time goes by under mild stress, through longer-term tests using even higher acute stress.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.32 no.1
• /
• pp.67-74
• /
• 2005

The aim of this study was to analyze the relationship between salivary flow, salivary buffer capacity, level of mutans streptococci and dental caries experience in Korean dental college students. A total of 81 students of the school of dentistry, Chonbuk national university, mean age of 26.1 years, were subjected to oral examination to establish the DMFT and DMFS according to WHO guidelines. Saliva samples from the students were collected for quantitating stimulated and unstimulated salivary flow rate. Buffering capacity was estimated using a commercial colorimetric strip test, and number of mutans streptococci was determined from stimulated saliva using a strip mutans test. The means of DMFT and DMFS were 6.57 and 12.65, respectively. The stimulated salivary flow rate was correlated with DMFT(${\acute{o}}\;=\;-0.219$) and high levels of salivary mutans streptococci were significantly correlated with higher DMFT and DMFS scores(P<0.05). Level of mutans streptococci was significantly correlated with dental caries experience, in both DMFT and DMFS score, and buffering capacity was inversely correlated to DMFT score. However, unstimulated salivary flow rate was not correlated with caries experience.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.12
• /
• pp.329-334
• /
• 2017

In this study, a new granular type mouthwash with equivalent antibacterial activity to marketed liquid type mouthwash was developed using a material called magnesium aluminometasilicate (Neusilin). This material adsorbs the surface of granules to improve the flowability of granules due to the formation of a eutectic mixture of the main constituents, which have improved flow properties and rapid disintegration time and little residue in the oral cavity. The characteristics of the granules were improved when the amount of Neusilin was 10% or more according to measurements of the granule properties, such as flowability. In addition, a disintegration test in artificial saliva and a sensory test in the human oral cavity were carried out to confirm the improved disintegration characteristics and sensory test results. The antimicrobial test confirmed similar antibacterial activity to that of the liquid oral cleanser already sold in the market. The granular oral cleanser composition prepared in this study can be used for the development of pharmaceuticals containing different drugs with similar characteristics as eutectic mixtures at the same time, which is considered to be useful in the development of medicines in the pharmaceutical industry.

• Journal of dental hygiene science
• /
• v.14 no.4
• /
• pp.477-487
• /
• 2014

Of the many pathogenic Candida species, Candida albicans is the main fungal pathogen of humans. The oral environmental factors considered in the Candida albicans colony forming unit test contain both host and microbial factors associated with candidiasis. In particular, Candida biofilms can develop on surfaces of prosthesis. The purpose of this study was to investigate the distribution of oral Candida species between the type of prosthesis and the situation of oral environment in patient with prosthetic appliance. The patients were 30 elderly subjects with different types of prosthesis, 7 who wore denture, 12 who wore implant and 15 who wore removable orthodontic appliance. We used Candida albicans colony forming unit test using saliva to exam the distribution of Candida albicans related with 5 oral environmental factors, gender, smoking or nonsmoking, alcohol/nonalcohol consumption, the type of prosthetic appliance and its treatment duration as well as tooth brushing frequency per day. In conclusion, for the patient's gender, site in the oral cavity and the type of prosthetic appliance and its treatment duration was associated with an increase in the distribution of Candida albicans in saliva. The distribution of Candida albicans within the oral cavity performs to be modulated to varying extents by oral environmental factors and, further investigations are required to elucidate these complex interactions.