• The Journal of Korean Academy of Prosthodontics
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• v.40 no.4
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• pp.309-322
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• 2002

The purpose of this study was to investigate the cytotoxicity and mutagenicity of denture base resins. According to manufacturer's instructions, resin specimens were made. Group 1 : heat-polymerizing acrylic resin (Luciton $199^{(R)}$) Group 2 : heat-polymerizing acrylic resin containing polyhedraloligosilsesquioxane(POSS resin) Group 3 : auto-polymerizing acrylic resin (Repair $Acrylic^{(R)}$) Group 4 : direct relining auto-polymerizing acrylic resin (Tokuso $Rebase^{(R)}$). Fresh specimens 24 hrs. and 72 hrs. soaked specimens in distil)ed water were made. Responses with metabolic assay and mutagenesis assay to eluates from resin specimens were measured. Cultures with medium alone provided controls. Cytotoxicity was assessed with agar overlay test. The results were as follows; 1. Group 4 showed higher cytotoxicity than Group 1, Group 2 and Group 3 in fresh, 24-an4 72-hour immersion caries (p<.05). Group 3 showed higher cytotoxicity than Group 2 in fresh cases and showed higher cytotoxicity than Group 1 and Group 2 in 24-and 72-hour immersion cases (p<.05) . Group 1 and Group 2 showed no significant difference. 2. All acrylic denture base resins skewed significant increase of cell activity as immersion time increased (p<.05). 3. Auto-polymerizing acrylic denture base resins skewed higher cytotoxicity than heat-polymerizing acrylic denture base resins (p<.05). 4. All acrylic denture base resins showed lower mutagenicity than controls (p<.05).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.160-161
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• 2021

To prepare polyurethane coatings for top coatings of automobiles, acrylic resins containing 75% of solids were synthesized by a radical polymerization. The viscosity of the acrylic resins was increased with increasing OH values. Crosslinked acrylic-urethane clear coatings were obtained by curing reaction between the synthesized acrylic resins and hexamethylene diisocyanate(HDI) trimer(Desmodur N-3600). The physical properties from the following studies were carried out : viscosity(Zahn cup #2), adhesion, pensil hardness, and 60° specular gloss. Various properties of the acrylic-urethane clear coatings as top coatings of mobile coat were evaluated on the coating specimens. Adhesion property to a substrate, 60° specular gloss, and pencil hardness of prepared paint showed quite good properties.

• Journal of the Korean Applied Science and Technology
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• v.24 no.3
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• pp.253-263
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• 2007

Three different weather-resistant coatings were fabricated with the various weight ratios of a mill-base silicone/acrylic resin to let-down silicone /acrylic resin at 2:8, 3:7, and 4:6 respectively. The prepared coatings were tested to investigate the effect of composition of weather-resistant coatings on the physical properties. The thermal stability, salt spray exposure, and weather-resistance were improved with the increased silicone content. It was concluded that the optimum retio of mill-base silicone/acrylic resin to let-down silicone/acrylic resin would be 2:8 and the coating with 30 wt% of silicone content would have high weather-resistance.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.164-165
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• 2021

To prepare the good-adherent and weather-resistant acrylic resin coatings, acrylic resin was prepared by a radical polymerization. Glass transition temperature(Tg) of the acrylic copolymer was fixed at 30℃ and the contents of tertiary amine monomer(DMAEMA) was varied to be 5, 10, 15, 20 wt% respectively. γ-Glycidoxypropyltrimethoxysilane(GPTMS) containing epoxy group was used for curing agents and di-n-butyltindilaurate(DBTDL) was used for drying accelerator. The equivalent ratio of amine to epoxy was 1:1. The prepared coatings exhibited excellent adhesion to various substrates, and various physical properties of the coatings were satisfactory. The gloss retention and color difference were improved at low tertiary amine concentration. The coatings containing 10wt% tertiary amine concentration have especially good weather resistant properties.

• Journal of Technologic Dentistry
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• v.35 no.4
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• pp.287-293
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• 2013

Purpose: This study is to provide basic data of the dental acrylic denture base resin in the mechanical property difference investigation according to the monomer composition weight ratio of the acrylic denture base resin. Methods: The monomer composition of the acrylic denture base resin and weight ratio makes the different specimen. It measured the mechanical property with the specimens through Hardness Test, Tensile Test, Flexural Test, Flexural Modulus, FT-IR Test. Results: The control group Vertex was 18.4 Hv and the experimental group MED was 14.46~19.07Hv in the hardness test. Vertex was 364N, MED-3 was lowest in the tensile strength test and the Head of a family cursor declination was big. The result declination of the experimental specimens showed. Vertex and MED-2 was the highestest in the flexural test and after coming MED-6, MED-5, MED-1, MED-3, MED-4. Vertex and MED-2, as to a spectrum for $500{\sim}1800cm^{-1}$ peak can show the excellent degree of polymerization in the FT-IR Test. Conclusion: The ideal weight ratio of the monomer of the acrylic denture base resin of which the mechanical property is the highestest was MMA 100g, EDGMA 5g, DMA 0.2g, of MED-2.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.6
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• pp.712-721
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• 2006

Statement of problem. Acrylic resin is most commonly used for denture bases. However, acrylic resin has week points of volumetric shrinkage during polymerization that reduces denture fit. The expandability of POSS (Polyhedral Oligomeric Silsesquioxane) containing polymer could be expected to reduce the polymerization shrinkage of denture bases and would increase the adaptability of the denture to the tissue. Purpose. The purpose of this study was to compare the dimensional stability in the conventional acrylic resin base, POSS-containing acrylic resin base, and metal bases. Materials and methods. Thirty six maxillary edentulous casts and dentures of different base were fabricated. Tooth movement and tissue contour change of denture after processing (resin curing, deflasking, decasting and finishing without polishing) and immersion in artificial saliva at $37^{\circ}C$ for 1 week and 4 weeks were measured using digital measuring microscope and threedimensional laser scanner. Results. The results were as follows: 1. The conventional resin group showed significant (p<0.01) dimensional change throughout the procedure (processing and immersion in artificial saliva). 2. After processing, the metal group and POSS resin group showed lower linear and 3-dimensional change than conventional resin group (p<0.01). 3. There was no statistically significant linear and 3-dimensional change after immersion for 1 week and 4 weeks in metal and POSS resin group. 4. In all groups, the midline and alveolar ridge crest area presented smaller 3-dimensional change compared with vestibule and posterior palatal seal area after processing and soaking in artificial saliva for 1 week and 4 weeks (p<0.01). Conclusion. In this study, a reinforced acrylic-based resin with POSS showed good dimensional stability.

• The Journal of Advanced Prosthodontics
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• v.6 no.1
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• pp.30-34
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• 2014

PURPOSE. This study evaluated the adhesion to acrylic resin specimens and biofilm formation capability of Candida albicans strains isolated from HIV positive subjects' oral rinse solutions. MATERIALS AND METHODS. The material tested was a heat-cured acrylic resin (Acron Duo). Using the adhesion and crystal violet assays, 14 oral Candida albicans isolated from HIV-positive subjects and 2 references Candida strains (C. albicans ATCC 90028 and C. albicans ATCC 90128) were compared for their biofilm production and adhesion properties to acrylic surfaces in vitro. RESULTS. There were no significant differences in adhesion (P=.52) and biofilm formation assays (P=.42) by statistical analysis with Mann-Whitney test. CONCLUSION. Denture stomatitis and increased prevalence of candidal carriage in HIV infected patients is unlikely to be related to the biofilm formation and adhesion abilities of C. albicans to acrylic resin materials.

• Journal of the Korean Wood Science and Technology
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• v.24 no.4
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• pp.47-55
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• 1996

UV transmission spectra of water-soluble acrylic resin films containing hydroxybenzophenolic, hydroxyphenylbenzotriazolic UV absorber and HALS(hindered amine light stabilizer) were investigated by exposure time(before exposure weathered for 160 and 320hours) in QUV Weather-Ometer. Also the YID(yellowness index difference), LID(lightness index difference) and CD(color difference) of dried water-soluble acrylic resin films and the coated woods of Larix leptolepis were analyzed by addition level of UV absorber(0, 1, 2 and 3%) and HALS(0, 0.5, 1 and 1.5%) and by exposure time in QUV Weather-Ometer. They showed no significant effects on UV transmission spectra of dried water-soluble acrylic resin films in the range of 300 to 400nm irrespective of exposure time. However, UV transmission decreased as increase of exposure time. UV transmission spectra were lower in dried water-soluble acrylic resin films containing hydroxybenzophenolic UV absorber and HALS than in these containing hydroxyphenylbenzotriazolic UV absorber and HALS in the range of 350 to 400nm. The least YID, LID and CD in the coated woods of Larix leptolepis appeared at the addition level of 3%, based on non-volatile content, in hydroxybenzophenolic and hydroxyphenylbenzotriazolic UV absorber, and of 1.5% in HALS to water-soluble acrylic resin.

• The Journal of Advanced Prosthodontics
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• v.4 no.3
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• pp.121-126
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• 2012

PURPOSE. The aim of the study was to evaluate the effect of 3 silicone primers and 3 surface characterization of acrylic resin surface on bond strength between silicone elastomer and acrylic resin. MATERIALS AND METHODS. 96 Cosmesil silicones bonded to heat-curing acrylic resin were fabricated with the dimension of $75{\times}10{\times}3$ mm. The 3 primers used in this study were G611 platinum primer, A-330 Gold platinum primer, and cyanoacrylates resin. Specimens without primer were used as control. The 3 types of surface characterization done were retentive holes with 1.5 mm in diameter and 0.5 mm deep, retentive beads of 0.6 mm diameter and the third type which was plain without any characterization. The specimens were then checked for bond strength by subjecting them to $180^{\circ}$ peel test on a universal testing machine. The obtained results were then subjected to statistical analysis using 2-way ANOVA and Scheff$\acute{e}$ multiple post hoc procedures. The statistical significance was set at 5% level of significance. RESULTS. The maximum bond strength was seen for samples in which A-330G primer was used followed by G611 primer. The control group showed the minimum bond strength. Surface characterization of retentive holes increased the bond strength considerably as compared to retentive beads and samples without any surface characterization. CONCLUSION. Within the limitations of the study, A-330G primer was more compatible with Cosmesil M511 silicone and has better bonding of Cosmesil to acrylic resin. Retentive holes made on acrylic surface increased the bond strength considerably than those without any surface characterization.

• The Journal of Korean Academy of Prosthodontics
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• v.23 no.1
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• pp.155-164
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• 1985

Acrylic resin has some disadvantages in its physical properties such as a low surface hardness, being easily abraded as well as low degree of impact resistance. To overcome these disavantages, Perma Cure System was introduced in 1981, in which photo polymerizing monomers coated on acrylic resin surface were polymerized. In this study, to observe the effect of Perma Cure System on physical properties of treated surface of different types of acrylic resin, abrasion resistance, surface hardness and surface roughness of 4 different types of resin (Premium, Ortho-jet acrylic, Quick resin, Thermo jel) were tested before and after coating treatment. The conclusions arised from this study are as follows; 1. In all types of resin, the abrasion resistance of coated specimen was higher than that of uncoated specimen, and there was difference in amount of abrasion among the types of coated resin. 2. In all types of resin, the surface hardness of coated specimen was higher than that of uncoated specimen, and there was no difference in surface hardness among the types of coated resin. 3. In all types of resin, surface roughness of coated specimen was lower than that of uncoated specimen, and was different according to the degree of surface roughness before coating treatment in same sort of resin specimen.