• 대한치과보철학회지
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• 제38권2호
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• pp.160-168
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• 2000

This study evaluated the effects of four adhesive metal primers on the shear bond strength of a heat curing denture base resin(Lucitone 199) to cobalt-chromium alloy(Biosil-f). The adhesive metal primers were Cesead Opaque Primer, Metal Primer, MR Bond, and Super-Bond liquid. The metal surface primed or nonprimed was filled with the heat-curing methyl methacrylate resin. The specimens were stored in water at $37^{\circ}C$ for 24 hours and the alternately immersed in water bath at $5^{\circ}C\;and\;55^{\circ}C$ for up to 2,000 thermal cycles. Shear bond strengths were measured using UTM at a crosshead speed of 0.5mm/min. Failure surface were examined under magnifying glasses. All the primers examined improved the shear bond strength between denture base resin and cobalt-chromium alloy compared with nonprimed specimens before thermal cycling. The bond strength of Cesead Opaque Primer was greatest. And after 2,000 thermal cycles, the bond strengths between resin and cobalt-chromium alloy were decreased but the difference between thermal cycling 0 and 2,000 at Cesead Opaque primer and Metal Primer were not significant. This study indicated that Cesead Opaque Primer & Metal Primer is effective primers to obtain higher bond strength between heat cured denture base resin and cobalt-chromium alloy.

• 한국염색가공학회지
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• 제34권3호
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• pp.157-164
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• 2022

This study tried to analyze the heat resistance properties by blending epoxy and phenolic resin in a certain ratio, and to analyze the adhesive properties at the time of metal-polymer hetero-adhesion by applying Epoxy-phenolic resin between a silicon steel sheet and m-aramid sheet, the viscosity, adhesive peel strength, and adhesive cross section were measured using a rotational rheometer, a tensile tester(UTM), and a field emission scanning electron microscopy(FE-SEM). The thermal stability and heat resistance were confirmed by measuring the mass loss according to the temperature increase using Thermogravimetric analysis(TGA). After blending with epoxy and Phenolic resin(1:0.25 ratio) curing at 110℃ for 10 min, high adhesive strength was improved more than 40% compared to the adhesive strength using epoxy alone. When the space between the silicon steel sheet and m-aramid sheet, which is created during curing of the E-P blend, is cured with a slight weight, it is possible to control the empty space and improve adhesion.

• 대한치과보철학회지
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• 제40권3호
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• pp.236-245
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• 2002

The acrylic resin was first introduced as denture base materials in 1937 and it is commonly used for denture base fabrication nowadays. Three different curing cycles (Conventional curing cycle, short curing cycle and long curing cycle) and three commercially available heat-activated acrylic resins (Vertex RS, Lucitone 199 and ProBase Hot) were investigated to find the curing cycle and material that showed the minimum shrinkage of the resin during polymerization process. A brass master mold was fabricated and duplicated by additional silicone impression material. Stone molds were made by pouring of type III dental stone (SILKY-ROCK YELLOW, Whip-Mix, Louisville, Kentucky). It was embedded in the flask. Strain gauge and thermocouple were embedded in the specimen. Strain gauge and thermocouple were connected to signal conditioning amplifier and data was recorded by pre-programmed software. The parameters ESmax (Maximum expansion strain), Sb (Strain measured just before deflasking procedure), Sa (Strain measured just after deflasking procedure) and Sf (Strain measured at the end of the experiment) were measured. ${\Delta}$S was calculated from Sb and Sa (${\Delta}$S=Sb-Sa). In the experiment concerned about materials, the parameters 90-ESmax (Maximum expansion strain measured during early 90 minutes of curing procedure), 180-ESmax (Maximum expansion strain measured from 90 minutes to 180 minutes), Sb, Sa, ${\Delta}$S and Sf were measured and the following conclusions were made. 1. The ESmax value of conventional curing cycle showed the largest value and the 180-ESmax value of Lucitone 199 showed the smallest value. 90-ESmax values showed no significant difference (p<0.05). 2. ${\Delta}$S values of conventional curing cycle showed the positive values. ${\Delta}$S values of short curing cycle and long curing cycle showed the negative values. All three materials cured by conventional curing cycle showed the positive values. 3. The Sf values of long curing cycle and ProBase Hot (cured by conventional curing cycle) showed the smallest values.

• 대한치과보철학회지
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• 제28권2호
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• pp.29-51
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• 1990

This study was designed to compre the tensile bond strength of 4-META containging denture base resin to Co-Cr alloys after various surface treatments. Especially the surface treatment of sandblasting the mental with aluminum oxide and treating in oxidizing solution composed of 3% aqueous sulfuric acid with 1% potassium manganate were compared. Effect of surface roughness on bonding was measured after sandblasting with 50um, 300um aluminun oxide and polishing with emery pater. Also the effects of wax and wax solvent on bonding were observed. According to the type of polymerization process, heat-cured Meta-Dent resin and autopolymerizing Meta-Fast resin were used. For some specimnens, the tensile bond strength were measured agter three pre-conditions : 1day after bonding, immersed in water at $75^{\circ}C{\pm}3^{\circ}C$ for 4weeks, under normal ambient condition for 4weeks. The following results were obtained from this study : 1. The bond strengths of resins containing 4-META were significantly higher than those of conventional denture base resins(p<0.05). 2. Autopolymerizing Meta-Fast resin had higher bond strength than heat-cured Meta-Dent, resin(p<0.05). 3. The bond strengths of Biosil and Nobilium to 4-META containging resins were not significally different(p>0.05). 4. Stable adhesion can be achieved when mechanically roughen the metal surface by snadblasting with $50{\mu}m$ aluminum oxide than treating in an oxidizing soluing with potassium manganate(p<0.05). 5. Once the metal surface is contaminated with wax, the bond srtength decreased greatly in spite of wax wash with boiling water. But the bond strength recovered significantly with the use of wax solvent 6. Meta-Dent resin had higher bond strength when roughen the metal surface with $50{\mu}m$ aluminum oxide than with $300{\mu}m$ aluminum oxide(p<0.05). In case of Meta-Fast, resin, the use of $300{\mu}m$aluminum oxide was a little advantageous of bonding, but was statistically insignificant(p>0.05).

• 대한치과기공학회지
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• 제43권2호
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• pp.56-61
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• 2021

Purpose: This study aimed to produce resin prosthetics using a dental automatic barrel finishing. Surface roughness and surface topography of resins were observed according to the grinding time of the dental automatic barrel finishing. Methods: This study was performed with thermopolymer, autopolymer, and photopolymer resins. The dimensions of the specimen were 10×10×2 mm. Each specimen was polymerized according to the manufacturer's instructions. The polymerized resin was honed for 30 minutes at 5-min intervals in a dental automatic barrel finishing. The specimen was observed using a three-dimensional (3D) optical microscope, and the surface roughness was measured. Results: After the polishing with the dental automatic barrel finishing, the heat-cured (HC) specimen showed the highest and lowest values of Ra after 10 and 15 minutes, respectively. The self-cured (SC) specimen showed the highest and lowest values of Ra after 10 and 25 minutes, respectively. Finally, the 3D specimen showed the highest and lowest values of Ra after 5 and 20 minutes, respectively. Conclusion: After measuring the surface roughness of the three types of resins according to the grinding time of the dental automatic barrel finishing, the lowest Ra values for the HC, SC, and 3D specimens were measured after 15, 25, and 20 minutes, respectively. Therefore, we concluded that a limit on the grinding time of the resin using a dental automatic barrel finishing is needed.

• 접착 및 계면
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• 제14권3호
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• pp.135-145
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• 2013

환경친화형 반도체 봉지재로서 할로겐 화합물 등의 첨가형 난연제를 혼합하지 않고 자기소화성을 발현시키는 에폭시수지 조성물에 관해 연구하였다. 탄화수소계 방향족 공액이중결합의 구조를 갖는 에폭시수지와 페놀수지의 반응물에서 자기소화성을 갖는 낮은 연소열이 확인되었다. 본 연구에서는 탄화수소계 방향족 공액이중결합에 헤테로원자계 이중결합인 아조메틴기를 도입하여 더욱 낮은 연소열을 확인할 수 있었다. 낮은 연소열의 결과는 높은 반응열과 열전이온도 그리고 빠른 반응성과 관련이 있으며 아조메틴기의 헤테로원자 구조의 영향 때문으로 보인다.

• 구강회복응용과학지
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• 제37권4호
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• pp.232-243
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• 2021

목적: 다양한 3D 프린팅 의치상 레진과 여러 가지 의치 첨상 재료 간의 전단결합강도를 평가하여 기존의 열중합 의치상 레진과의 전단결합강도를 비교 평가하고자 하였다. 연구 재료 및 방법: 열중합레진(Vertex RS)과 3D프린팅 의치상 레진 두종(DENTCA Denture base II, NextDent^TM Base)을 사용하였다. 의치 첨상 재료로는 성분이 다른 총 4종(Tokuyama Rebase II fast, Kooliner, Denture Liner, Denture Liner, Lang Jet Denture Repair Kit)을 사용하여 12개의 군으로 분류하였다. ISO/TS 11405규격에 따라 접착을 시행하였다. 전단결합강도를 측정하였고, 이후 입체현미경과 주사전자현미경을 이용하여 접착 계면을 관찰하고 파절편의 분석을 통하여 파절 양상을 조사하였다. 결과: 3D 프린팅 의치상 레진 군에서 의치 첨상 재료와의 전단결합강도가 열중합레진 군에 비해 유의하게 낮은 전단결합강도 결과를 나타내었다(P < 0.05). Polymethyl methacrylate계열의 첨상재료의 경우, 의치상종류와 관계없이 높은 전단결합강도를 보였다. 파절 양상은 대부분의 군에서 접착성 파절이 나타났고 일부 군에서 응집성 파절과 혼합성 파절 양상이 나타났다. 결론: Polymethyl methacrylate를 주성분으로 하는 의치 첨상 재료가 실험에 사용된 모든 의치상 레진에서 다른 의치 첨상 재료와 비교하여 높은 전단 결합강도 값을 나타내었지만, 직접법으로 의치 첨상을 시행할 경우 단량체로 Isobutyl methacrylate 성분의 의치 첨상재료를 사용하는 것이 전단결합강도면에서 유리할 것으로 사료된다.

• 한국응용과학기술학회지
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• 제20권3호
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• pp.237-242
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• 2003

The high-solid coatings were prepared by blending the synthesized acrylic resin in the previous paper and hexamethylene diisocyanate-trimer and curing it at room temperature. The characterization of the films of the prepared coatings was performed. The impact resistance, $60^{\circ}C$ specular gloss, cross-hatch adhension, and heat resistance of the films proved to be good, and the pencil hardness and drying time proved to be slightly poor. Especially, there was a remarkable improvement in the heat resistance. This improvement may stem from the regular arrangement of ethyl groups introduced into the acrylic resin. From a viscoelastic measurement using a rigid-body pendulum, curing was accelerated with the $T_g$ value. With the increase in $T_g$, log damp value was lowered and dynamic viscoelasic $T_g$ of a cured film was increased.

• Advances in materials Research
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• 제11권2호
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• pp.165-170
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• 2022

Acrylic resin or polymethylmethacrylate (PMMA) is one of the most attractive materials to be used for dental appliances manufacturing. It has been introduced as a biomaterial during the last century. This study aims to evaluate the compounds absorption and release through acrylic resin to be used for drug delivery as well. The study specimens were 10 pieces of heat-cured clear acrylic resin with dimensions of 10 × 10 × 2 mm. The specimens were dipped in methylene blue solution at a powder-water ratio of 1:20 for 5 days. The samples were removed and dipped in 5 ml distilled water vials for 24 hours. Then the specimens were replaced into new 5 ml vials and the process lasted for 4 days. The extracted solutions were analyzed by the visible light spectroscopy for absorbance. The statistical results showed a gradual increase in stain release from day 1 to day 4 with a significant difference between day 1 and day 4 solutions. The study showed that PMMA resin is able to absorb and release some compounds constantly and the absorption drug-loading technique is applicable to this material.

• The Journal of Advanced Prosthodontics
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• 제5권3호
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• pp.287-295
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• 2013

PURPOSE. This study investigated the effect of laser parameters and air-abrasion on the peel strength of silicon-based soft denture liner to different denture resins. MATERIALS AND METHODS. Specimens (N=180) were prepared out of three different denture base resins (Rodex, cross-linked denture base acrylic resin; Paladent, heat-cured acrylic resin; Deflex, Polyamide resin) ($75mm{\times}25mm{\times}3mm$). A silicon-based soft denture liner (Molloplast B) was applied to the denture resins after the following conditioning methods: a) Air-abrasion ($50{\mu}m$), b) Er,Cr:YSGG laser (Waterlase MD Turbo, Biolase Technology) at 2 W-20 Hz, c) Er,Cr:YSGG laser at 2 W-30 Hz, d) Er,Cr:YSGG laser at 3 W-20 Hz, e) Er,Cr:YSGG laser at 3 W-30 Hz. Non-conditioned group acted as the control group. Peel test was performed in a universal testing machine. Failure modes were evaluated visually. Data were analyzed using two-way ANOVA and Tukey's test (${\alpha}$=.05). RESULTS. Denture liner tested showed increased peel strength after laser treatment with different parameters ($3.9{\pm}0.4-5.58{\pm}0.6$ MPa) compared to the control ($3.64{\pm}0.5-4.58{\pm}0.5$ MPa) and air-abraded groups ($3.1{\pm}0.6-4.46{\pm}0.3$ MPa), but the results were not statistically significant except for Paladent, with the pretreatment of Er,Cr:YSGG laser at 3 W-20 Hz. Polyamide resin after air-abrasion showed significantly lower peel strength than those of other groups ($3.1{\pm}0.6$ MPa). CONCLUSION. Heat-cured acrylic resin, PMMA, may benefit from Er,Cr:YSGG laser treatment at 3 W-20 Hz irradiation. Air-abrasion of polyamide resins should be avoided not to impair their peel bond strengths to silicon-based soft denture liners.