• Title/Summary/Keyword: biomaterials

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Position of maxillary central incisor and intercanine width in Korean adults (한국 유치악 성인의 상악 중절치 위치 및 견치간 거리에 관한 연구)

  • Yang, Dong-Hun;Lee, Jee-Yun;Ban, Jae-Sam;Oh, Gye-Jeong;Park, Sang-Won
    • The Journal of Korean Academy of Prosthodontics
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    • v.51 no.3
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    • pp.147-152
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    • 2013
  • Purpose: The aim of this study was to propose the position of maxillary anterior teeth and intercanine width measurements based on the incisive papilla in accordance with the cephalic type and gender of dentate Korean adult with normal teeth alignment. Materials and methods: 42 students with Class I normal occlusion, without crowding or spacing, were selected from the Chonnam National University School of Dentistry. The lateral skull radiographs of the subjects were taken and were classified as different cephalic types, based on their PFH / AFH ratios. 42 casts of their maxilla were prepared and both the distance between the upper central incisors and the middle of the incisor papilla was measured with a vernier caliper (A) and the distance between the maxillary canine cusp tips (B) were measured. Statistical analysis was performed using SPSS version 15 and their significance was investigated. Results: For dolichocephalic group, the mean values for A and B were 8.43 (SD: 0.61) and 36.73 (SD: 2.17), respectively. The mean value for A was 8.51 (SD: 1.27) for the mesocephalic group and 8.76 (SD 1.03) for the brachycephalic group. The mean value for B was 35.91 (SD: 1.86) for the mesocephalic group and 37.34 (SD: 2.23) for the brachycephalic group. For the male group, the mean A value was 8.86 (SD: 1.04) and the mean B value was 37.60 (SD: 0.24). For the female group, the mean A value was 8.41 (SD: 0.93) and the mean B value was 36.18 (SD: 2.01). The difference between male and female group in A values were not statistically significant (P>.05). The B values of the male subjects were greater than those of the female subjects and was statistically significant (P<.05). Conclusion: 42 students with normal dentition and occlusion in korea, the distance from the incisive papilla and the incisal edge of maxillary central incisors had no difference in cephalic type or gender. However, the distance between the cusp tip of both canines had significant difference in gender where the male showed higher values than the female, while having no difference in cephalic types.

Color stability of three dimensional-printed denture teeth exposed to various colorants (다양한 색소에 대한 3D 프린팅 인공치의 색 안정성)

  • Koh, Eun-Sol;Cha, Hyun-Suk;Kim, Tae-Hyung;Ahn, Jin-Soo;Lee, Joo-Hee
    • The Journal of Korean Academy of Prosthodontics
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    • v.58 no.1
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    • pp.1-6
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    • 2020
  • Purpose: This study evaluated color stability of Dentca 3D-printed denture teeth, in comparison to color stabilities of four conventional types of denture teeth, upon being immersed in various colorants. Materials and methods: Four types of conventional prefabricated denture teeth (Surpass, GC, Artic 6, Heraeus Kulzer, Premium 6, Heraeus Kulzer, Preference, Candulor), 3D-printed denture teeth (Dentca); and Z250 (Filtek Z250, 3M ESPE) were prepared for testing. The samples were immersed in erythrosine 3%, coffee, cola, and distilled water (DW) at 37℃. Color change (ΔE) was measured by spectrophotometer before immersion and at 7, 14, and 21 days after immersion. One-way analysis of variance was performed along with Tukey's honestly significant difference multiple comparisons test (P<.05). Results: No great difference was observed between the color change of Dentca denture teeth and that of conventional denture teeth in most cases (P>.05). The color change of Dentca denture teeth immersed in erythrosine 3% was greater than that of Surpass (ΔE = 0.67 ± 0.25) after 1 week; Artic 6 (ΔE = 1.44 ± 0.38) and Premium 6 (ΔE = 1.69 ± 0.35) after 2 weeks; and Surpass (ΔE = 1.79 ± 0.49), Artic 6 (ΔE = 2.07 ± 0.21), Premium 6 (ΔE = 2.03 ± 0.75), and Preference (ΔE = 2.01 ± 0.75) after 3 weeks (P<.05). Conclusion: A color change was observed in Dentca denture teeth when immersed in some colorants; however, the maximum value of ΔE for Dentca denture teeth was within the clinically acceptable range.

The Effects of 7 Fertilizers on the Growth and Nutrient Concentrations of Fraxinus rhynchophylla, Fraxinus mandshurica, Pinus koraiensis, and Abies holophylla Seedlings (7가지 시비처리가 물푸레나무, 들메나무, 잣나무, 전나무 묘목의 생장 및 양분농도에 미치는 영향)

  • Han, Si Ho;Byun, Jae Kyung;Cho, Min Seok;An, Ji Young;Park, Gwan Soo;Kim, Se Bin;Park, Byung Bae
    • Journal of Korean Society of Forest Science
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    • v.105 no.2
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    • pp.177-185
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    • 2016
  • Fertilization is required to keep the balance of tissue nutrients and to produce high quality seedlings at the permanent nursery. This study was conducted to verify the optimum fertilization method for Fraxinus rhynchophylla, F. mandshurica, Pinus koraiensis, and Abies holophylla seedlings with vector diagnosis method. Seven treatments include nitrogen (N, $13.8g{\cdot}m^{-2}$), phosphorus (P, $6.1g{\cdot}m^{-2}$), potassium ($7.5g{\cdot}m^{-2}$) fertilization and 1x (N $6.9g{\cdot}m^{-2}$, P $3.05g{\cdot}m^{-2}$, K $3.65g{\cdot}m^{-2}$), 2x (twice of 1x), 4x (four times of 1x) fertilization and no fertilization. Soil pH decreased as fertilization increased. Nitrogen and NPK fertilization decreased exchangeable $Ca^{2+}$ and $Mg^{2+}$ concentrations. Height and root collar diameter of F. rhynchophylla and F. mandshurica significantly increased with N and NPK fertilization, but those of P. koraiensis and A. holophylla did not. The biomass of F. rhynchophylla and F. mandshurica was about twice higher at NPK fertilization compared to the control. The responses of vector diagnosis were different by tree species and fertilization treatment: F. rhynchophylla was in the status of N "dilution", which means the N concentration decreases with N content. Phosphorus and K were "sufficiency" state with 4x fertilization. F. mandshurica showed "retranslocation" as N content decreased without change of dry weight at N, P, K fertilization, but "dilution" state at NPK fertilization. This result suggested that optimal fertilization was required for F. rhynchophylla and F. mandshurica in seedling production stage, but was not essential for P. koraiensis and A. holophylla.

Chemical Composition and Immunostimulating Activity of the Fermented Korean Ginseng (Panax ginseng C.A. Meyer) with Mushroom Mycelium by Solid Culture (균사체를 이용한 수삼 고체발효물의 화학적 조성 및 면역 활성)

  • Park, Chang-Kyu;Kim, Hoon;Tu, Qi;Yu, Kwang-Won;Jeong, Heon-Sang;Lee, Hyeon-Yong;Jeong, Jae-Hyun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.9
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    • pp.1145-1152
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    • 2009
  • For the utilization of Korean ginseng (Panax ginseng C.A. Meyer) in the functional drink, we prepared the fermented Korean ginseng with mushroom mycelia (Ganoderma lucidum; WG-GL, Hericium erinaceum; WG-HE and Phellinus linteus; WG-PL) by solid culture. A proximate analysis showed that the fermented Korean ginseng contained significantly more crude fat (4.66$\sim$12.02%) than Korean ginseng (WG, 1.61%) whereas crude protein content of WG (13.64%) was higher value than those of the ferments (7.60$\sim$12.57%). When we also evaluated effects of the fermented Korean ginseng on the mitogenic activity, hot-water extract from WG-PL was significantly higher than those of WG or mycelia only fermentation (GL, HE and PL) as analyzed by IL-2 production (1.64-fold of the saline control) and proliferation of splenocytes (1.47-fold). In addition, the lysosomal phosphatase activity (WG-HE; 1.32-fold) and NO/TNF-$\alpha$ production (WG-HE; 2.27-fold of the saline control at 50 ${\mu}g$/mL, WG-PL; 3.56-fold, respectively) from macrophage in the presence of the fermented Korean ginseng were higher than those of WG or mycelia fermentation. These results indicate that hot-water extracts from the fermented Korean ginseng with mushroom mycelia by solid culture contain chemical ingredients different from the Korean ginseng, and that it might provide beneficial immunostimulating activity.

Effect of Sodium Fluoride Varnish and Potassium Iodide on Remineralization Efficacy of Silver Diamine Fluoride (불화나트륨 바니쉬와 요오드화 칼륨이 Silver Diamine Fluoride의 재광화 효과에 미치는 영향)

  • Lee, Kunho;Ahn, Junyong;Kim, Jong Soo;Han, Miran;Lee, Joonhaeng;Shin Jisun
    • JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY
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    • v.48 no.4
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    • pp.467-475
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    • 2021
  • The purpose of this study was to compare the effect of sodium fluoride(NaF) varnish and potassium iodide(KI) on remineralization efficacy of silver diamine fluoride(SDF) by measuring microhardness and evaluating surface morphology by scanning electron microscope(SEM). Artificial caries lesions were induced on extracted primary molars and vickers microhardness was measured. Specimens were randomly separated into 4 groups for treatment. The specimens in group I were treated with SDF, group II with NaF varnish after SDF, group III with KI after SDF and group IV with distilled water. After 8 days of pH cycling, vickers microhardness was measured and difference before and after treatment was calculated. For SEM, 2 samples were evaluated respectively after enamel polishing, lesion formation and after pH cycling. Group III showed highest increase in microhardness. Group I showed higher increase in microhardness than Group II but without statistical difference. Group IV showed lowest increase in microhardness value among 4 groups. On SEM image, group I, II and III showed smoother and less irregular surface compared to group IV. Amorphous crystal pellicles were observed in group III. In conclusion, SDF, SDF and NaF, SDF and KI groups showed smoother surface and increase in microhardness suggesting the possibility that remineralization effect might take place in oral conditions. In addition, in limited conditions of this study, applying NaF varnish after SDF did not increase the remineralization efficacy of SDF while KI significantly increased the remineralization efficacy of SDF. However, additional study considering various conditions that might affect demineralization and remineralization in clinical situations need to be conducted.

Evaluation of Antimicrobial Activity of Steamed and Fermented Asparagus cochinchinenesis (증숙 및 발효한 천문동의 항균활성과 특성)

  • Lee, Seung-Min;Kim, Su-In;Kang, Moon-Sun;Lee, Chung-Yeol;Hwang, Dae-Youn;Lee, Hee-Sup;Kim, Dong-Seob
    • Food Engineering Progress
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    • v.21 no.2
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    • pp.143-149
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    • 2017
  • This study was carried out to investigate antimicrobial activity and characteristics of Asparagus cochinchinenesis which was steamed and fermented with lactic acid bacteria. A. cochinchinensis was prepared to steaming process which was washed and freeze dried. A. cochinchinensis was steamed at $95^{\circ}C$ for 12 h and dried by hot air at $50^{\circ}C$ for 24 h. After steaming process, A. cochinchinensis was fermented with lactic acid bacteria (Leuconostoc mesenteroides 4395, Lactobacillus sakei 383 and Lactobacillus plantarum KCCM 11322). Ethyl acetate extracts of fermented A. cochinchinensis had antimicrobial activities for the respiratory disease bacteria (Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Escherichia coli). A. cochinchinensis had highest antimicrobial activity for the P. aeruginosa which fermented with L. mesenteroides 4395. The minimum inhibition concentration (MIC) of A. cochinchinensis fermented with L. mesenteroides 4395 was 10 mg/mL for S. aureus, S. epidermidis, E. coli and 5 mg/mL for P. aeruginosa. The MIC of A. cochinchinensis fermented with L. sakei 383 and A. cochinchinensis fermented with L. plantarum KCCM 11322 were the same. Total sugar was decreased from $863.33{\pm}17.47mg/mL$ to $722.67{\pm}5.51mg/mL$ during the steaming process. But reducing sugar was increased from $99.36{\pm}1.32mg/mL$ to $109.29{\pm}2.71mg/mL$ during the steaming process. Total sugar was decreased to 301.50-361.42 mg/mL and reducing sugar was decreased to 27.39-62.20 mg/mL during the fermentation process.

Dietary effect of Bacillus subtilis MD-02 on Innate Immune Response and Disease Resistance in Olive Flounder, Paralichthys olivaceus (넙치(Paralichthys olivaceus)의 비특이적 면역반응 및 병 저항성에 대한 Bacillus subtilis MD-02의 효과)

  • Kim, Dong-Hwi;Heo, Moon-Soo
    • Microbiology and Biotechnology Letters
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    • v.47 no.1
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    • pp.132-138
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    • 2019
  • Among several marine-derived microorganisms isolated from the coast of Jeju Island that had antimicrobial activity against fish disease pathogens, Bacillus subtilis MD-02 was tested for its dietary effect on the innate immune response and disease resistance of olive flounder. Strain MD-02 was fed to the olive flounder at a concentration of $1.2{\times}10^4$, $1.2{\times}10^6$, or $1.2{\times}10^8CFU/100g$, respectively. Consequently, the hematocrit was higher in these three groups than that in the control group at 4 weeks, and the aspartate aminotransferase and alanine aminotransferase levels were decreased in the $1.2{\times}10^8$ and $1.2{\times}10^4CFU/100$ groups compared with the control group levels. The amylase activity and total protein were significantly increased in the $1.2{\times}10^4CFU/100g$ group at 3 weeks. The innate immune response, determined from the lysozyme and macrophage activities, was higher in the $1.2{\times}10^8CFU/100g$ group than in the control group. In addition, treatment of the olive flounders with Streptococcus parauberis at $1.2{\times}10^6CFU/ml$ confirmed the mortality rate, which was 100% in the control group and 40-60% in the groups fed B. subtilis MD-02, indicating that the fish had resistance to fish disease pathogens. Therefore, it was confirmed that when fed MD-02, olive flounder builds an innate immune response and acquires resistance to fish disease pathogens, indicating that B. subtilis MD-02 can be developed as a beneficial feed additive.

Degree of Conversion and Polymerization Shrinkage of Low and High Viscosity Bulk-Fill Giomer-based and Resin-based composites (저점도 및 고점도 Bulk-fill Giomer 복합레진과 Bulk-fill 복합레진의 전환율과 중합수축)

  • Kim, Heera;Lee, Jaesik;Kim, Hyunjung;Kwon, Taeyub;Nam, Soonhyeun
    • JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY
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    • v.46 no.1
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    • pp.1-9
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    • 2019
  • The aim of this study was to compare the degree of conversion and polymerization shrinkage of low and high viscosity bulk-fill giomer-based and resin-based composites. Two bulk-fill giomer (Beautifil Bulk Restorative (BBR), Beautifil Bulk Flowable (BBF)), two bulk-fill (Tetric N-Ceram Bulk-fill (TBF), SureFil SDR flow (SDR)) and two conventional resin composites (Tetric N-Ceram (TN), Tetric N-flow (TF)) were selected for this study. The degree of conversion was measured by using Fourier transform infrared spectroscopy. Polymerization shrinkage was measured with the linometer. For all depth, BBR had the lowest degree of conversion and SDR had the highest. At 4 mm, the degree of conversion of low and high viscosity bulk-fill giomer resin composites was lower than that of bulk-fill resin composites (p < 0.05). At the depth between 2 mm and 4 mm, there were significant difference with TBF, TN and TF (p < 0.05), while no significant difference in the degree of conversion was measured for BBR, BBF and SDR. Polymerization shrinkage of six resin composites decreased in the following order: TF > SDR > BBF > TBF > TN and BBR (p < 0.05). Polymerization shrinkage of bulk-fill giomer resin composites was lower than that of bulk-fill resin composites (p < 0.05). From this study, it is found that the bulk-fill giomer resin composites and TBF were not sufficiently cured in 4 mm depth. The degree of conversion of low and high viscosity bulk-fill giomer resin composites was significantly lower than bulk-fill resin composites in both 2 mm and 4 mm depths. Therefore, such features of bulk-fill giomer resin composites should be carefully considered in clinical application.

The micro-tensile bond strength of two-step self-etch adhesive to ground enamel with and without prior acid-etching (산부식 전처리에 따른 2단계 자가부식 접착제의 연마 법랑질에 대한 미세인장결합강도)

  • Kim, You-Lee;Kim, Jee-Hwan;Shim, June-Sung;Kim, Kwang-Mahn;Lee, Keun-Woo
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.2
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    • pp.148-156
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    • 2008
  • Statement of problems: Self-etch adhesives exhibit some clinical benefits such as ease of manipulation and reduced technique-sensitivity. Nevertheless, some concern remains regarding the bonding effectiveness of self-etch adhesives to enamel, in particular when so-called 'mild' self-etch adhesives are employed. This study compared the microtensile bond strengths to ground enamel of the two-step self-etch adhesive Clearfil SE Bond (Kuraray) to the three-step etch-and- rinse adhesive Scotchbond Multi-Purpose (3M ESPE) and the one-step self-etch adhesive iBond (Heraeus Kulzer). Purpose: The purpose of this study was to determine the effect of a preceding phosphoric acid conditioning step on the bonding effectiveness of a two-step self-etch adhesive to ground enamel. Material and methods: The two-step self-etch adhesive Clearfil SE Bond non-etch group, Clearfil SE Bond etch group with prior 35% phosphoric acid etching, and the one-step self-etch adhesive iBond group were used as experimental groups. The three-step etch-and-rinse adhesive Scotchbond Multi-Purpose was used as a control group. The facial surfaces of bovine incisors were divided in four equal parts cruciformly, and randomly distributed into each group. The facial surface of each incisor was ground with 800-grit silicon carbide paper. Each adhesive group was applied according to the manufacturer's instructions to ground enamel, after which the surface was built up using Light-Core (Bisco). After storage in distilled water at $37^{\circ}C$ for 1 week, the restored teeth were sectioned into enamel beams approximately 0.8*0.8mm in cross section using a low speed precision diamond saw (TOPMET Metsaw-LS). After storage in distilled water at $37^{\circ}C$ for 1 month, 3 months, microtensile bond strength evaluations were performed using microspecimens. The microtensile bond strength (MPa) was derived by dividing the imposed force (N) at time of fracture by the bond area ($mm^2$). The mode of failure at the interface was determined with a microscope (Microscope-B nocular, Nikon). The data of microtensile bond strength were statistically analyzed using a one-way ANOVA, followed by Least Significant Difference Post Hoc Test at a significance level of 5%. Results: The mean microtensile bond strength after 1 month of storage showed no statistically significant difference between all adhesive groups (P>0.05). After 3 months of storage, adhesion to ground enamel of iBond was not significantly different from Clearfil SE Bond etch (P>>0.05), while Clearfil SE Bond non-etch and Scotchbond Multi-Purpose demonstrated significantly lower bond strengths (P<0.05), with no significant differences between the two adhesives. Conclusion: In this study the microtensile bond strength to ground enamel of two-step self-etch adhesive Clearfil SE Bond was not significantly different from three-step etch-and-rinse adhesive Scotchbond Multi-Purpose, and prior etching with 35% phosphoric acid significantly increased the bonding effectiveness of Clearfil SE Bond to enamel at 3 months.