• The Journal of Korean Academy of Prosthodontics
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• v.31 no.2
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• pp.207-218
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• 1993

The purpose of this study was to evaluate the reproducing accuracy of stone casts made from complete arch impressions using different impression materials. The impression materials studied were 1) polyether, 2) polysulfide, 3) polyvinyl siloxane, and 4) irreversible hydrocolloid. Impressions were made from a partially edentulous acrylic resin model with metal inserts in canine, first molar region bilaterally and mid palatal vault region. Each distance between 2 out of 5 meauring points was measured by using 3dimensional measuring machine. Impressions were poured at once with a type IV dental stone. Data were analyzed using t-test with a sample size of six. The results were as follow : 1. Polysulfide and polyether were significantly superior to polyvinyl siloxane and irreversible hydrocolloid in reproducing full arch model(p<0.05), but there were no statistical differences in amount of dimensional reproducing accuracy for full arch impression between polysulfide and polyether(p>0.05). 2. There were statistical differences in amount of dimensional reproducing accuracy between edentulous area and tooth bound area for polysulfide and polyether(p<0.05). but no statistical differences were observed for polyvinyl siloxane and irreversible hydrocolloid(p>0.05).

• Korean journal of food and cookery science
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• v.24 no.5
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• pp.636-644
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• 2008

The principal objective of this study was to assess the effects of hydrocolloids(xanthan gum, guar gum, sodium alginate, k-carrageenan, carboxy-methyl cellulose) on the suppression of retrogradation in the bread. The pasting properties of the doughs and the sensory properties were determined in the bread samples, to which xanthan gum, guar gum, sodium alginate, k-carrageenan, and CMC, were added at different ratios(0.2%, 0.6%, 1%). CMC and k-carrageenan with 0.6% level were selected for the further retrogradation studies. Changes in the firmness of the bread samples at room temperature for 15 days were assessed using a texture analyzer, and the type of retrogradation was calculated via the Avrami equation. The thermal properties of the samples were also determined via differential scanning calorimetry (DSC). The addition of hydrocolloids was shown to increase the viscosities of the doughs. Setback and breakdown viscosity were reduced significantly via the addition of CMC(0.6%, 1%), xanthan gum(1%), and k-carrageenan(1%). Sensory hardness was significantly increased when 1% hydrocolloids were added. Our textural analysis showed that the addition of CMC reduced the firmness of the bread, whereas k-carrageenan didn't. However, the retrogradation rate was reduced via the addition of k-carrageenan, as was also demonstrated in the results of our DSC analysis.

• The Journal of the Korean dental association
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• v.1 no.1
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• pp.121-123
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• 1954

• The Journal of the Korean dental association
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• v.26 no.5 s.228
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• pp.389-391
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• 1988

• Proceedings of KHEA Conference
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• 2004.04a
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• pp.114-114
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• 2004

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.294-301
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• 2003

This study was performed to compare the effects of hydrocolloid(Duoderm$\circledR$, HC in this study) and hydrogel (Nu-Gel$\circledR$, HG in this study) occlusive dressing materials on degree of exudate, wound contraction, epithelialization, and healing of full-thickness skin wound in dogs. Three wounds measuring 2${\times}$2 cm in size were created bilaterally(6 wounds/dog) on the dorsolateral aspect of the trunk of 12 dogs. In each dog, the wounds were treated with HC, HG, and normal saline, respectively. For a 4 week period, the wounds were evaluated gross aspects and histopathological aspects. There were no statistically significant differences between treatment groups in percentage of wound contraction, percentage of epithelialization, and percentage of wound total healing during the first week. Significant differences were first detected on day 14. On day l4(P < 0.01) and 21 (P < 0.05), mean percentage of epithelialization of HG-treated wound was significantly greater than those in HC- and normal saline-treated wound. Mean percentage of wound contraction of HG-treated wound was significantly greater than that in HC- and control wounds on day 21(P< 0.05). On day 21, mean percentage of wound healing of HG-treated wound was significantly greater than that in HC- and control wounds(P < 0.02). On day 1, 4, and 7 after wound creation, although severe infiltration of PMN (polymorphonuclear leukocyte) cells in HC- and control wounds were observed in the subcutis and moderate infiltration of PMN cells in HG-treated wound were observed in the subcutis, we did not detect significant differences. On day 14 after wounding creation, in the wounds treated with HG dressing, epithelial cells were found over the surface, and edema further decreased in the tissue under the wounds, and the granulation tissue was replaced with collagen fibers. On day 21 after wound creation, in HG-treated wound compared with other experimental material-treated wounds, regenerated epidermis covered most of the wound surface, and the granulation tissue was more replaced with collagen fibers than that on day 14. Overall results indicated that the use of hydrogel dressing materials(Nu-Gel$\circledR$) as hydrocolloid dressing (Duoderm$\circledR$) materials and normal saline treatment on full-thickness skin wounds in dogs increased the rate of healing at repair stage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.438-444
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• 2002

Interactions between meat proteins and hydrocolloids in a model system may play an important role for the improvement of textural properties in low-fat sausage mixtures. The objective of this study was to determine gel properties as affected by the type and level of hydrocolloid, various pH values of meat protein-hydrocolloid mixture before cooking, and internal cooking temperatures. The desirable heat-induced gels (HIGs) were formed at least pH values above 6.0. The addition of konjac flour (KF), kappa-carrageenan (CN) and locust bean gum (LBG) to extracted salt soluble proteins (2%) improved the gel strength with increased levels (0.5∼1.5%) and HIGs containing CN had the highest (p<0.05) gel strength. The increase of cooking temperature increased gel strength, depending on pH and type of hydrocolloid. However, the minimun internal cooking temperature to make viscoelastic HIGs was 70$^{\circ}C$. These results indicated that desirable HIGs were manufactured with each hydrocolloid concentration of 1% and minimum cooking temperature of 70$^{\circ}C$ with pH values higher than 6.0.

• Korean journal of food and cookery science
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• v.12 no.1
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• pp.20-26
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• 1996

The present study was attempted to investigate and to evaluate various hydrocolloids as a stabilizer in improving texture of the frozen yogurt. Four kinds of hydrocolloids used in this study were CMC (carboxymethyll cellulose), PGA(propylene glycol alginate), LMP(low methoxyl pectin), and the combination of LBG(locust bean gum) and GG(guar gum). The viscosity of frozen yogurt mixes did not show any significant differences among four samples at 5$^{\circ}C$. However, as the temperature increased up to 50$^{\circ}C$, theviscosity of frozen yogurt mixes containing CMC, LMP, PGA decreased drastically except frozen yogurt containing the combination of LBG+GG. The overrun of frozen yogurt containing each hydrocolloid gradually increased and reached to about 53, 50, 54, and 35%, respectively, after 40 min of operating ice cream freezer. As the result of sensory evaluation in the texture of frozen yogurt and melt-down quality, the sample containing LMP was described as the most coarce & icy, crumbly, and sand-like characters. On the other hand, PGA sample was evaluated as not being icy, crumbly, but being chewy and soft in texture. However, any significant differences among four samples were not shown in melt-down quality.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.2
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• pp.101-107
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• 2021

Time-temperature integrators (TTIs) based on aqueous enzyme solutions produce transparent colors which lead to difficulty in distinguishing its color change by naked eye. In this present study, this issue has been solved by increasing the opacity of laccase-based TTI without changes in the kinetics (same zero-order reaction) and temperature dependency (similar Arrhenius activation energy values) of the color change. The opacity was increased by introducing TiO₂, latex, BaSO₄, or ZnO, in combination with a hydrocolloid (xanthan gum, acacia gum, pectin, and CMC) into the TTI system. The combination of TiO₂ and xanthan gum was the best. This finding broadened the advantages of laccase-based TTI to more practical uses for consumer convenience.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.5
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• pp.503-513
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• 2006

Statement of the problem: The cold-cured resins used in fabrication of the provisional crown and fixed partial dentures could cause pulpal damage by heat generated during exothermic polymerization reactions. Purpose: In this in vitro study investigates the how external conditions such as material of the matrix, thickness of the matrix and thickness of dentin affect the temperature of the tooth during polymerization reaction of the cold-cured resins. Material and methods : To measure the temperature of the resin, metal die was maintained to the temperature of $37^{\circ}C$ with water bath to simulate the temperature of thetooth and thermocouple was placed in the center of the metal die. Acrylic pipe was cut in height of 1, 2, 3, 6, 10 mm and placed on the metal die and mixed resin was pored in the acrylic pipe As the resin polymerized temperature was recorded with the thermometer. Temperature of the resin using matrix was recorded by using the individual tray relieved in different thickness 2, 5, 7, 10 mm. The material of the matrix was irreversible hydrocolloid impression material, vinyl polysilloxane impression material and vacuum-formed template Temperature rise of the resin using different thickness of tooth section was record ed by placing tooth section on the metal die and placing resin over the tooth section. Results : Conclusion : 1. Temperature rise increased as the thickness of the resin increased but there was no significant differences over 3 mm thickness of the resin. 2. The lowest temperature rise was showed in irreversible hydrocolloid impression material and vinyl polysilloxane impression material vacuum-formed template as in orders. 3, Temperature rise of the resin decreased regardless of the thickness of the matrix when vinyl polysilloxane impression material was used as the matrix. 4 When irreversible hydrocolloid impression material was used as matrix, the temperature rise of the resin decreased as the thickness of the matrix increased and there was no temperature rise when thickness of the matrix reached 10 mm, 5. The temperature rise of the resin did not decreased when Polypropylene vacuum-formed template was used as the matrix. 6, The temperature of the resin increased as the thickness of the dentin decreased.