1.Reconstruction of hand.
Kyungjin LEE ; Dongchul LEE ; Siyoung ROH ; Jinsoo KIM
Journal of the Korean Medical Association 2016;59(2):127-135
The characteristics of hand trauma are changing due to automation of industrial facilities, improved access to health care, and the aging population. Since the inception of hand surgery as a subspecialty, hand defects have been reconstructed with the restoration of the original functionality as the primary goal. With advancement and maturation of surgical techniques, however, restoration of aesthetics also began to take hold as an important aspect of hand surgery practice. After the first successful replantation of an amputated digit, the rapid development of microsurgical techniques had a significant impact on the field of reconstructive hand surgery. In the first two decades, the success of replantation was evaluated by the survival rate for a single operator or a specialized institution. These days, however, microsurgical techniques have been widely adopted, with digital replantation possible even for infants. In addition to various local flaps, the evolution of free flaps has vastly expanded the repertoire of reconstructive options for hand surgeons. With the wide variety of free flaps available, it is possible for a severely injured hand to be salvaged and restored to its original functional and aesthetic status. In South Korea, hand surgery is becoming an established profession with a separate subspecialty certification. Hand surgery has a bright outlook, with future research directed at new biocompatible materials and novel reconstructive methods.
Aging
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Automation
;
Biocompatible Materials
;
Certification
;
Esthetics
;
Free Tissue Flaps
;
Hand*
;
Health Services Accessibility
;
Humans
;
Infant
;
Korea
;
Microsurgery
;
Replantation
;
Survival Rate
2.Study of Bacteria Associated with Dental Caries Using a 3 Tone Disclosing Agent
Jeongeun LEE ; Howon PARK ; Juhyun LEE ; Hyunwoo SEO ; Siyoung LEE
Journal of Korean Academy of Pediatric Dentistry 2018;45(1):32-40
The aim of this study was to determine the efficacy of a 3 tone plaque disclosing gel in assessing the risk of caries related to the population of Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus spp. quantified using a quantitative real-time polymerase chain reaction (qRT-PCR).15 healthy children of ages 9 – 12 years were randomly examined. The 3 tone plaque disclosing gel was applied on teeth surfaces, which changed the color to pink or red, blue or purple and light blue. Plaque was divided into 3 groups based on staining. Genomic DNA from each sample was subjected to a qRT-PCR assay for quantitative detection of target bacteria. The Kruskal-Wallis test was conducted for correlation between the color of plaque and the number of bacterial species.The levels of S. mutans, S. sobrinus, and Lactobacillus spp. were significantly different in the plaque samples of the 3 groups (p < 0.05). The proportion of S. sobrinus to S. mutans showed correlation to the color of plaque.The different color-dyed plaque was related to the number of acidogenic bacteria. The 3 tone plaque disclosing gel could be used as one of the indicators to assess the clinical risk of caries associated with the population of S. mutans, S. sobrinus, and Lactobacillus spp.
Bacteria
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Child
;
Dental Caries
;
Dental Plaque
;
DNA
;
Humans
;
Lactobacillus
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Real-Time Polymerase Chain Reaction
;
Streptococcus mutans
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Streptococcus sobrinus
;
Tooth
3.Effect of Sub-minimal Inhibitory Concentration of Chlorhexidine on Biofilm Formation and Coaggregation of Early Colonizers, Streptococci and Actinomycetes.
International Journal of Oral Biology 2016;41(4):209-215
Chlorhexidine has long been used in mouth washes for the control of dental caries, gingivitis and dental plaque. Minimal inhibitory concentration (MIC) is the lowest concentration of an antimicrobial substance to inhibit the growth of bacteria. Concentrations lower than the MIC are called sub minimal inhibitory concentrations (sub-MICs). Many studies have reported that sub-MICs of antimicrobial substances can affect the virulence of bacteria. The aim of this study was to investigate the effect of sub-MIC chlorhexidine on biofilm formation and coaggregation of oral early colonizers, such as Streptococcus gordonii, Actinomyces naeslundii and Actinomyces odontolyticus. The biofilm formation of S. gordonii, A. naeslundii and A. odontolyticus was not affected by sub-MIC chlorhexidine. However, the biofilm formation of S. mutans increased after incubation with sub-MIC chlorhexidine. In addition, cell surface hydrophobicity of S. mutans treated with sub-MIC of chlorhexidine, decreased when compared with the group not treated with chlorhexidine. However, significant differences were seen with other bacteria. Coaggregation of A. naeslundii with A. odontolyticus reduced by sub-MIC chlorhexidine, whereas the coaggreagation of A. naeslundii with S. gordonii remained unaffected. These results indicate that sub-MIC chlorhexidine could influence the binding properties, such as biofilm formation, hydrophobicity and coaggregation, in early colonizing streptococci and actinomycetes.
Actinobacteria*
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Actinomyces
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Bacteria
;
Biofilms*
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Chlorhexidine*
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Colon*
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Dental Caries
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Dental Plaque
;
Gingivitis
;
Hydrophobic and Hydrophilic Interactions
;
Mouth
;
Streptococcus gordonii
;
Virulence
4.Effect of Sub-Minimal Inhibitory Concentrations of Antibiotics on Biofilm Formation and Coaggregation of Streptococci and Actinomycetes.
International Journal of Oral Biology 2015;40(4):189-196
Minimal inhibitory concentration (MIC) is the lowest antibiotic concentration that inhibits the visible growth of bacteria. Sub-minimal inhibitory concentration (Sub-MIC) is defined as the concentration of an antimicrobial agent that does not have an effect on bacterial growth but can alter bacterial biochemistry, thus reducing bacterial virulence. Many studies have confirmed that sub-MICs of antibiotics can inhibit bacterial virulence factors. However, most studies were focused on Gram-negative bacteria, while few studies on the effect of sub-MICs of antibiotics on Gram-positive bacteria. In this study, we examined the influence of sub-MICs of doxycycline, tetracycline, penicillin and amoxicillin on biofilm formation and coaggregation of Streptococcus gordonii, Streptococcus mutans, Actinomyces naeslundii, and Actinomyces odontolyticus. In this study, incubation with sub-MIC of antibiotics had no effect on the biofilm formation of S. gordonii and A. naeslundii. However, S. mutans showed increased biofilm formation after incubation with sub-MIC amoxicillin and penicillin. Also, the biofilm formation of A. odontolyticus was increased after incubating with sub-MIC penicillin. Coaggregation of A. naeslundii with S. gordonii and A. odontolyticus was diminished by sub-MIC amoxicillin. These observations indicated that sub-MICs of antibiotics could affect variable virulence properties such as biofilm formation and coaggregation in Gram-positive oral bacteria.
Actinobacteria*
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Actinomyces
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Amoxicillin
;
Anti-Bacterial Agents*
;
Bacteria
;
Biochemistry
;
Biofilms*
;
Doxycycline
;
Gram-Negative Bacteria
;
Gram-Positive Bacteria
;
Hydrophobic and Hydrophilic Interactions
;
Penicillins
;
Streptococcus gordonii
;
Streptococcus mutans
;
Tetracycline
;
Virulence
;
Virulence Factors
5.Application of Teeth Whitening LED for Prevention of Dental Caries : Antimicrobial Photodynamic Therapy Approach
Choa PARK ; Howon PARK ; Juhyun LEE ; Hyunwoo SEO ; Siyoung LEE
Journal of Korean Academy of Pediatric Dentistry 2020;47(1):70-77
The present study is aimed to assess the effect of antimicrobial photodynamic therapy (aPDT) on Streptococcus mutans biofilm through teeth whitening light emitting diode (LED).
Planktonic and dynamic biofilm state cultures of S. mutans were used. Erythrosine 20 μM/L was used as the photosensitizer. Irradiation was performed by exposing cultures to clinic and homecare whitening LEDs for 15 minutes. The viability was measured through Colony Forming Unit counts and confocal laser scanning microscopy.
aPDT using whitening LEDs and erythrosine significantly decreased the CFU count of S. mutans compared to that in the control group. Dynamic biofilm group showed more resistant features to aPDT compared with planktonic state. Clinic and homecare whitening LED device showed similar antimicrobial effect.
The whitening LED, which could irradiate the entire oral arch, showed a significant photodynamic effect on cariogenic S. mutans biofilm. aPDT mediated by erythrosine and LEDs used for teeth whitening exhibited promising antimicrobial activity.
6.Surface Roughness and Microbial Adhesion After Finishing of Alkasite Restorative Material
Choa PARK ; Howon PARK ; Juhyun LEE ; Hyunwoo SEO ; Siyoung LEE
Journal of Korean Academy of Pediatric Dentistry 2020;47(2):188-195
This study is aimed to evaluate and compare the surface roughness and microbial adhesion to alkasite restorative material (Cention N), resin-modified glass ionomer (RMGI), and composite resin. And to examine the correlation between bacterial adhesion and surface roughness by different finishing systems.
Specimens were fabricated in disk shapes and divided into four groups by finishing methods (control, carbide bur, fine grit diamond bur, and white stone bur). Surface roughness was tested by atomic force microscope and surface observation was performed by scanning electron microscope. Colony forming units were measured after incubating Streptococcus mutans biofilm on specimens using CDC biofilm reactor.
Cention N surface roughness was less than 0.2 μm after finishing procedure. Control specimens of resin and Cention N specimens were significantly (p = 0.01) rougher. Pearson correlation coefficient (PCC = 0.13) indicated a weak correlation between surface roughness and S. mutans adhesion to the specimens.
Compared with resin specimens, RMGI and Cention N showed lower microbial adhesion. Surface roughness and bacterial adhesion were not significantly different, regardless of the finishing systems.
7.Antimicrobial Effect of Photodynamic Therapy Using Plaque Disclosing Agent
Junhee KHO ; Howon PARK ; Juhyun LEE ; Hyunwoo SEO ; Siyoung LEE
Journal of Korean Academy of Pediatric Dentistry 2020;47(2):120-127
The aim of this study was to evaluate the antimicrobial effect of photodynamic therapy (PDT) using plaque disclosing agent, 10 - 20 mM erythrosine, as a photosensitizer.
Multispecies cariogenic biofilms containing Streptococcus mutans , Lactobacillus casei and Candida albicans were formed on hydroxyapatite disc. 20 μM, 10 mM and 20 mM erythrosine were applied as a photosensitizer for 3 minutes, and then light-emitting diode (LED) irradiated for 24 seconds. Colony-forming unit (CFU) were measured and biofilms were observed using confocal laser scanning microscopy (CLSM). CFU were significantly decreased in the PDT groups using 10 - 20 mM erythrosine (10 mM, 20mM) and the results were also confirmed by CLSM.
This study confirms the high antimicrobial effect of photodynamic therapy using plaque disclosing agent as a photosensitizer.
8.Streptococcus Mutans Biofilm Inhibition Effect of Indocyanine Green and Near Infrared Diode Laser
Yeowon KIM ; Howon PARK ; Juhyun LEE ; Hyunwoo SEO ; Siyoung LEE
Journal of Korean Academy of Pediatric Dentistry 2020;47(4):446-453
The purpose of this study was to evaluate the effect of Indocyanine Green (ICG) and near-infrared (NIR) diode laser on Streptococcus mutans biofilms depending on ICG concentrations.
S. mutans biofilms were formed on a Hydroxyapatite disk, and 0.5, 1.0, 2.0, 3.0, 4.0, 5.0 mg/mL ICG solutions dissolved in sterile distilled water and a NIR diode laser having a power of 300 mW and a wavelength of 808 nm were applied to the biofilms. The temperature changes of the biofilm surface according to the concentrations of the ICG solution were measured using a 1-channel thermocouple thermometer.
Compared to the control group, in the groups with only the 3.0, 4.0, 5.0 mg/mL ICG solution application, and in the groups with the 1.0, 2.0, 3.0, 4.0, 5.0 mg/mL ICG solution application and light irradiation, a statistically significant decrease in the bacterial counts were observed.
The temperature increase according to the concentration of the ICG solutions was 9.53℃, 10.43℃, 11.40℃, 12.10℃, 12.67℃, and 13.63℃ in ICG solutions of 0.5, 1.0, 2.0, 3.0, 4.0, and 5.0 mg/mL respectively.This study presents the potential for clinical application of ICG and NIR diode lasers as a new method for preventing dental caries.
9.Effect of Photothermal Therapy with Indocyanine Green in Multispecies Biofilm
Myunghwan KIM ; Howon PARK ; Juhyun LEE ; Hyunwoo SEO ; Siyoung LEE
Journal of Korean Academy of Pediatric Dentistry 2021;48(1):21-30
The purpose of this study is to investigate the antibacterial effects of indocyanine green (ICG) and near-infrared diode lasers on multispecies biofilms.
Multispecies biofilms of Streptococcus mutans, Lactobacillus casei and Candida albicans were treated with different irradiation time using photosensitizer ICG and 808 nm near-infrared diode laser. Colony forming unit (CFU) was measured, and qualitative evaluation of biofilm was performed with confocal laser scanning microscopy (CLSM). Temperature measurement was conducted to evaluate photothermal effect.
In the groups using ICG and diode laser, reduction in CFU was statistically significant, but the difference in antibacterial effect on L. casei and C. albicans with irradiation time was not significant, and similar results were confirmed with CLSM. Groups with ICG and diode laser showed higher temperature elevation than groups without ICG, and results of measured temperature were similar to the range of hyperthermia.
In conclusion, ICG and near-infrared diode laser showed antibacterial effects on multispecies biofilms, but studies on protocol are necessary for clinical application.
10.Antimicrobial Effect on Streptococcus mutans in Photodynamic Therapy using Different Light Source
Jaeyong KIM ; Howon PARK ; Juhyun LEE ; Hyunwoo SEO ; Siyoung LEE
Journal of Korean Academy of Pediatric Dentistry 2018;45(1):82-89
In a photodynamic therapy, the difference of antibacterial capacity was compared according to the type of source of light when the same quantity of energy is irradiated.After S. mutans is formed in planktonic state and biofilm state, erythrosine diluted to 40 µM was treated for 3 minutes, and as the type of light source, Halogen, LED, and Plasma arc were used, which were irradiated for 30 seconds, 15 seconds and 9.5 seconds, respectively.After the completion of the experiment, CFU of each experiment arm was measured to compare the photodynamic therapeutic effects according to each condition.The CFU of each experiment arm had no statistically significant difference.Under the same quantity of energy, the photodynamic therapeutic effect can be said to be the same regardless of types of light source, which is a useful result in the clinical field with various light irradiators.
Arm
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Biofilms
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Erythrosine
;
Photochemotherapy
;
Plankton
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Plasma
;
Streptococcus mutans
;
Streptococcus
;
Therapeutic Uses