• Korean Journal of Microbiology
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• v.27 no.4
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• pp.430-435
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• 1989

Dextranase and glucose-osidase was investigated as an anti-plaque agent and a component of dentifrice. In vitro synthesis of the water-insoluble glucan was decreased with increasing amount of dextranase and glucose-oxidase. Dextranase was effective on the decrease of viable S. mutans, and the formation of plaque decreased. But it is not effective on the degradatio of plaque. As a research for addition of enzyme to the dentifrice components, we formulated the Model Dentifrice for stabilization of enzyme. At the Model Dentifrice, we confirmed the stability of enzyme by evalution of activity for a long time.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.87-93
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• 2014

Dental plaque resides passively at a site and makes an active contribution to the maintenance of health. The bacterial composition of plaque remains relatively stable despite regular exposure to minor environmental stress. This stability, homeostasis is due to a dynamic balance of microbial interactions. However, the homeostasis can break down, leading to shifts in the balance of the microflora. This change can be a sign of initial dental caries. It is proposed that disease can be prevented or treated not only by targeting the putative pathogens but also by interfering with the processes that drive the breakdown in homeostasis. It is essential to understand the plaque as a mixed species biofilm. In this essay I reviewed an extension of the caries ecological hypothesis to explain the relation between dynamic changes in the phenotypic/genotypic properties of plaque bacteria and the demineralization and remineralization balance of the dental caries process. We will have the strategies to impact significantly on clinical practice as understanding dental biofilm.

• Korean Journal of Microbiology
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• v.32 no.1
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• pp.60-64
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• 1994

Pseudomonas syringae pv. tabaci produces tabtoxin and causes wildfire disease on tabacco and bean plants. In this study, bacteriophage of P. syringae pv. tabaci were isolated from sewage by top agar overlay method, and physiological and genetical characteristics of the phage were investigated. Plaques of isolated phage were turbid and ranged in size from 1 to 2 mm. The stability range of pH was between 6.0 and 9.0, and stability of temperature was up to 30${\circ}C$ and inactivated at 70${\circ}C$. The adsorption rate of phage was about 85% for 30min. The latent period and mean burst size as dertermined in one step growth experiments were 3 hrs and 200 PFU/bacterium, respectively. Genomic material of isolated phage was dsDNA of which size was about 30kb.

• Journal of Korean society of Dental Hygiene
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• v.10 no.2
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• pp.311-322
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• 2010

Objectives : Since the program about sodium lauryl sulfate that might cause oral dryness and taste change including oral tissue allergy was on the air, the ingredients of D.I.Y dentifrices without sodium lauryl sulfate have been sold in online shopping mall and ordinary people can make the dentifrices easily. But there have not been any reports about the effect of dental plaque removal and preference about D.I.Y dentifrices. Therefore, this study was designed as a pilot study which aimed to investigate the effect of dental plaque removal and prefernece about D.I.Y dentifrices. Methods : 6 subjects were collected to test the effect of dental plaque removal with D.I.Y dentifrices with written consent. They didn't brushed the teeth during 12 hours until the check-up time on the next day. The O'leary index was calculated in baseline, 1 minute, 2 minute, 3 minute after brusing with D.I.Y dentifrices and market dentifrices. The preference about D.I.Y dentifrices through self-administered questionnaire was surveyed in 51 subjects after using D.I.Y dentifrices. Results : 1. The market dentifrices could remove larger amount of dental plaque than D.I.Y dentifrices, but, it wasn't significant. 2. In feeling refreshment, the market dentifrices had more positive answers significantly. 3. In feeling taste change, the market dentifries had more duration of taste change significantly. 4. In feeling oral dryness, the market dentifrices had more duration of oral dryness after toothbrushing. but, it wasn't significant. 5. As a result about reviewing the dental journals about ingredients of D.I.Y dentirices, green tea, sodium carbonate, bamboo salt, propolis had each evidence. But, We could not find out the evidences of calculus adhesion by corn starch, preservative by napri, disinfectant of peppermint. Conclusions : Although we cannot find the difference of the effect of dental plaque removal between D.I.Y dentifrices and market dentifrices, and D.I.Y dentifrices have the merits of decrease of oral dryness and taste change, it was suggested to have another test about stability and safety of D.I.Y dentifrices for safety of the user of D.I.Y dentifrices.

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.2
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• pp.119-126
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• 2002

The purpose of this study was to restorate a patient who has a few remaining teeth with #15,23,24 supported Konus telescope denture in Maxillar and #44,43,33,34 supported Dolder bar retained overdenture in Mandible. Konus telescope and bar retained overdenture was taken better results in retention, support, stability compair with regular Removable partial denture. In Removable partial denture, the change of remaining teeth and edentulous ridge is natural. But Konus telescope and bar retained overdenture is a little effected in this change, so it is possiblble in long-term use. In cosider of patient's medical history and the possibility of additional tooth loss, Konus telescope denture can be easily repaired. Compaired with Konus telescope and bar retained overdenture showed high stability and easy cleansing because of rigid support, cross - arch splinting, and simple design. In delivery, patient had a difficulty with removal of denture and plaque control, but showed better condition, good oral hygienic care. Patient satisfied with denture functionally and esthetically. This study showed Konus telescope and bar retained overdenture was effective for treatment of patient remaing a few teeth in function, esthetic and psycologic satisfaction.

• Korean Journal of Microbiology
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• v.24 no.2
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• pp.161-167
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• 1986

Some of the physiological properties of Sp816 bacteriophage of Bacillus subtilis SNU816 were characterized. It could form plaques on either B. subtilis SNU816 or B. natto 8102, but not on any other bacillus strains investrgated. Its plaque morphology was circular with a diameter of less than 1.0mm and had a narrow halo surrounding the clear center. Its latent period was 34-36 min and had a burst size of 547. It was most stable at pH 6.0, and rapidly inactivated at $60^{\circ}C$ with a initial deaty rate of -0.216 $min^{-1}$. Host range, thermal inactivation rate at $60^{\circ}C$, pH stability, and UV sensitivity revealed that SP816 was quite different from any other phages investigated together but seemed to be rather related to B. natto phages.

• The Journal of Advanced Prosthodontics
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• v.3 no.1
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• pp.20-24
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• 2011

PURPOSE. The aim of this study was to identify in vitro antimicrobial activity of the tissue conditioner containing silver nanoparticles on microbial strains, Staphylococcus aureus, Streptococcus mutans and Candida albicans. MATERIALS AND METHODS. Experimental disc samples ($20.0{\times}3.0$ mm) of tissue conditioner (GC Soft-Liner, GC cooperation, Tokyo, Japan) containing 0.1 - 3.0% silver nanoparticles (0%: control) were fabricated. Samples were placed on separate culture plate dish and microbial suspensions (100 ${\mu}L$) of tested strains were inoculated then incubated at $37^{\circ}C$. Microbial growth was verified at 24 hrs and 72 hrs and the antimicrobial effects of samples were evaluated as a percentage of viable cells in withdrawn suspension (100 ${\mu}L$). Data were recorded as the mean of three colony forming unit (CFU) numerations and the borderline of the antimicrobial effect was determined at 0.1% viable cells. RESULTS. A 0.1% silver nanoparticles combined to tissue conditioner displayed minimal bactericidal effect against Staphylococcus aureus and Streptococcus mutans strains, a 0.5% for fungal strain. Control group did not show any microbial inhibitory effect and there were no statistical difference between 24 hrs and extended 72 hrs incubation time (P > .05). CONCLUSION. Within the limitation of this in vitro study, the results suggest that the tissue conditioner containing silver nanoparticles could be an antimicrobial dental material in denture plaque control. Further mechanical stability and toxicity studies are still required.

• Korean Journal of Microbiology
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• v.23 no.2
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• pp.107-114
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• 1985

In order to use for recipient strains of RP4:Mu cts, 5 strainsof Rhizobium were selected among 32 strains, which were isolated and identified in this study. Hybrid plasmin RP4::Mu cts, which, is temperature sensitive and confers resistance to ampicillin, kanamycin and tetracycline was transfered by conjugation from E. coli to other atrains of C. coli and the symbiotic nitrogen fixer, Rhizobium leguminosarum. Transfer frequencies of RP4::Mu cts plasmid from E. coli to Rhizobium were about $10^{-8}-10^{-7}$ in LB agar and YMA media. The transconjugants were confirmed by demonstrating that the drug-resistant and temperature-sensitive clones isolated were drug-resistant and temperature-sensitive clones isolated were capable of releasing phage and forming plaques. The plaque-forming units of transconjugants were about $10^2\;to\;10^3$. Stability test of RP4::Mucts in Rhizobium represented that most of the transconjugants had drug resistance and produce phage Mu cts.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.4
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• pp.225-231
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• 2022

Objectives: This study aims to evaluate the efficacy and safety of two types of sandblasted with large-grit and acid-etched (SLA) surface implants with different surface roughness. Patients and Methods: This study was conducted based on a clinical record review of 55 patients (mean age, 53.00 years). A total of 80 SLA surface implants was placed. Among the 80 implants, 38 implants placed in 29 subjects had surface roughness (Ra) of 3.09 ㎛ (test group, TG), while the other 42 implants placed in 31 subjects had a surface roughness (Ra) of 2.50 ㎛ (control group, CG). A comparison was made of implant primary/secondary stability; success and survival rates; marginal bone loss; and soft tissue assessment including probing pocket depth (PPD), plaque index (PI), gingival index (GI), and bleeding on probing (BOP) between the groups at 1 year after implant placement. Results: Among the implants that were initially registered, 1 from the TG and 4 from the CG dropped out, leaving 37 implants in the TG and 38 implants in the CG to be traced and analyzed. Although 1 TG case showed unstable primary stability, all cases showed stable secondary stability. Success and survival rates at 1 year after implant placement were 100% in both groups. Marginal bone loss was 0.07 mm and 0.00 mm for the TG and CG, respectively, but the difference was not significant. Among the several parameters for evaluation of soft tissue, the TG showed lower PI at 1 year after implant placement (TG=0.00, CG=0.29; P=0.0004), while the remaining categories showed no significant difference between the groups. Conclusion: This study shows that the two types of SLA implants with different surface roughness have no difference in efficacy or safety. Therefore, both of the implants can be used safely and with promising outcomes.

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.625-636
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• 2007

Marginal tissue recession makes problems like esthetics, root caries, hypersensitivity and plaque accumulation. Request for root coverage is higer than ever, especially esthetic problems involved. So techniques for root coverage hav been developed. There are some kinds of surgical techniques using soft tissue for root coverage. For example, free gingival graft, kinds of pedicle flap, subepithelial connective tissue graft(SCTG), and so on. Subepithelial connective tissue graft has many advantage for root coverage, that is less pain on donor site, good blood supply for graft, and more esthetic result. For this reaseon, this case report was performed to evaluate the effect of root coverage using subepithelial connective tissue graft. Three patients has Miller's class I marginal tissue recession and one patients has Miller's class III marginal tissue recession. The following period is 36.5 month on average. The results are as follows: 1. Root coverage of 100% was obtained in 5 of 6 defects, and 80% was obtained in 1 of 6 defects, The mean root coverage was 96,6% in six cases on 4 patients. 2. The mean root coverage was 3.83mm and mean recession depth decreased from 4mm to 0.16mm. 3. The mean width of clinical attached gingiva increased from 1.5mm to 4mm. The mean width of gained attached gingiva after surgery was 2.5mm. 4. The mean follow up period was 36.5 months. The longest follow up period was 50 months and the shortest follow up period was 22 months. 5. The result that obtained by surgery was stable during follow up period. Within the above results, root coverage with SCTG is an effective procedure to cover marginal tissue recession defect with long term stability.