• 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).

• 대한치과보철학회지
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• 제39권6호
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• pp.589-598
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• 2001

The fracture of acrylic resin dentures remains an unsolved problem. Therefore, many investigations have been performed and various approaches to strengthening acrylic resin, for example, the reinforcement of heat-cured PMMA resin using glass fibers, have been suggested over the years. The aim of the present study was to investigate the effect of short glass fibers treated with silane coupling agent on the transverse strength of heat-polymerized PMMA denture base resin. To avoid fiber bunching and achieve even fiber distribution, glass fiber bundles were mixed with PMMA powder in conventional mixer whose blade was modified to be blunt. Composite of glass fiber($11{\mu}m$ diameter, 3mm & 6mm length, silane treated) and PMMA resin was made. Transverse strength and Young's modulus were estimated. Glass fibers were incorporated with 1%, 3%, 6% and 9% by weight. Plasticity and workability of dough was evaluated. Fracture surface of specimens was investigated by SEM. The results of this study were as follows 1. 6% and 9% incorporation of 3mm glass fibers in the PMMA resin enhanced the transverse strength of the test specimens(p<0.05). 2. 6% incorporation of 6mm glass fibers in the PMMA resin increased transverse strength, but 9% incorporation of it decreased transverse strength(p<0.05). 3. When more than 3% of 3mm glass fibers and more than 6% of 6mm glass fibers were incorporated, Young's modulus increased significantly(p<0.05). 4. Workability decreased gradually as the percentage of the fibers increased. 5. Workability decreased gradually as the length of the fibers increased. 6. In SEM and LM, there was no bunching of fibers and no shortening of fibers.

• The Journal of Advanced Prosthodontics
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• 제8권4호
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• pp.290-295
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• 2016

PURPOSE. The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS. One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS. Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION. The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials.

• 대한치과보철학회지
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• 제53권1호
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• pp.58-65
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• 2015

완전 무치악 환자의 수복 시 총의치나 임플란트 지지 피개의치와 더불어 임플란트를 지대치로 이용하는 국소의치가 치료 방법의 하나로 고려될 수 있다. 적은 수의 임플란트를 전략적으로 중요한 위치에 식립한 후 가철성 국소의치로 수복할 경우, 임플란트를 통해 안정을 얻고 부가적으로 유지 및 지지를 확보할 수 있을 뿐만 아니라 광범위한 임플란트 식립을 통한 고정성 보철물에 비해 환자의 수술 부담을 줄여줄 수 있으며, 치료비용 절감 효과도 기대할 수 있다. 본 증례는 오랫동안 국소의치를 사용해 온 환자에서 치아 상실 후 잔존 치조골의 상태 및 환자의 요구를 고려하여 임플란트 지지 국소의치를 제작한 증례로서 전치부에 식립한 임플란트는 고정성 보철물로 수복하고 구치부의 짧은 임플란트는 지지 기능만 부여하였다. 또한 의치상과 클래스프를 열가소성 아크릴 레진으로 제작함으로써 기능적, 심미적으로 만족스러운 치료 결과를 얻었기에 이를 보고하는 바이다.

• 대한치과보철학회지
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• 제43권4호
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• pp.478-486
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• 2005

Statement of problem : Fracture and dimensional change of an acrylic resin denture are a rather common occurrence. Purpose : The purpose of this study was to compare differences in dimensional changes and flexural strength of separate maxillary complete dentures after immediate deflasking by injection molding and conventional compression processing. Material and method: To evaluate dimensional stability, the maxillary dentures were fabricated by using different materials and methods. Lucitone 199(Dentsply Trubyte. york, pennsylvania, USA) and Vertex(Dentimex, zeist, Netherlands) were used as materials. Compression and injection packing methods were used as processing methods. The impression surface of the dentures was measured by 3D Scann-ing System(PERCEPTRON USA) and overlapped original impression surface of the master cast. To evaluate flexural strength, resin specimens were made according to the different materials, powder/liquid ratio and processing methods. Flexural strength of the complete resin specimens (64mm$\times$10mm$\times$3.3mm) were measured by INSTRON 4467. (INSTRON, England) The data was analyzed by ANOVA, t-test and Tukey test. (p<.05 level of significance) Result: The results were as follows 1. There was no significant differences between master model and denture base for each group in overall dimensional changes. 2. Palatal area was more stable than flange or alveolar area in dimensional stability. but. there was no significant differences among each area. 3. Materials and power/liquid ratio had an effect on flexural strength. (P<.05) Especially materials was most effective. (P<.05) 4. Lucitone 199(powder/liquid ratio followed by manufacturer's direction) showed higher flexural strength than Vertex. Conclusion : Dimensional stability or flexural strength are affected by materials rather than packing techniques.

• The Journal of Advanced Prosthodontics
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• 제7권2호
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• pp.98-107
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• 2015

PURPOSE. The aim of this study was to appraise the some mechanical properties of polymethyl methacrylate based denture base resin polymerized by copolymerization mechanism, and to investigate the cytotoxic effect of these copolymer resins. MATERIALS AND METHODS. 2-hydroxyethyl methacrylate (HEMA) and isobutyl methacrylate (IBMA) were added to monomers of conventional heat polymerized and injection-molded poly methyl methacrylate (PMMA) resin contents of 2%, 3%, and 5% by volume and polymerization was carried out. Three-point bending test was performed to detect flexural strength and the elasticity modulus of the resins. To determine the statistical differences between the study groups, the Kruskall-Wallis test was performed. Then pairwise comparisons were performed between significant groups by Mann-Whitney U test. Agar-overlay test was performed to determine cytotoxic effect of copolymer resins. Chemical analysis was determined by FTIR spectrum. RESULTS. Synthesis of the copolymer was approved by FTIR spectroscopy. Within the conventional heat-polymerized group maximum transverse strength had been seen in the HEMA 2% concentration; however, when the concentration ratio increased, the strength decreased. In the injection-molded group, maximum transverse strength had been seen in the IBMA 2% concentration; also as the concentration ratio increased, the strength decreased. Only IBMA showed no cytotoxic effect at low concentrations when both two polymerization methods applied while HEMA showed cytotoxic effect in the injection-molded resins. CONCLUSION. Within the limitations of this study, it may be concluded that IBMA and HEMA may be used in low concentration and at high temperature to obtain non-cytotoxic and durable copolymer structure.

• 대한소아치과학회지
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• 제36권1호
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• pp.150-156
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• 2009

부분무치증 환자에게 사용되어온 기존의 가철성 장치는 wire의 노출로 인한 비심미성과 낮은 유지력 등의 문제점을 가지고 있다. 그 대안으로 제시된 탄성의치는 치은의 자연적인 색조를 투과시키는 얇고 강한 레진유지부로 인해 심미성이 크게 향상 되었으며 전체적인 의치상의 크기를 줄여주어 환자의 감각을 더욱 향상시킨다. 탄성의치의 유연성은 파절가능성을 감소시키며, 내재적 응력의 해소 작용으로 지대치와 잔존 골조직에 전달되는 저작력을 분산시킬 수 있다. 본 증례에서는 부분무치증을 보이는 10세 여아와 6세 남아에서 기존의 가철성 장치를 대체한 탄성의치를 사용하여 양호한 치료결과를 얻었다. 알지네이트로 상하악 인상을 채득하고 교합관계를 인기한 뒤 기공소에 제작을 의뢰하였다. 다음 내원 시 탄성의치를 $90^{\circ}C$의 물에 1분정도 담가두었다가 꺼내어 서서히 식힌 뒤 구강 내에 시적하였다. 레진유지부의 적합성을 확인하고 $Fit-Checker^{(R)}$를 이용해 조직이 심하게 눌리는 곳을 삭제하고 장치를 장착하였다. 두 명의 환아 모두 탄성의치의 더 나은 유지력과 향상 된 심미성에 만족하였다. 탄성의치는 부분무치증 환자에서 기존의 가철성 장치를 대체할 수 있는 좋은 재료로 여겨진다.

• 대한치과보철학회지
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• 제54권3호
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• pp.286-290
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• 2016

최근에 열가소성 레진 클라스프를 이용한 가철성 장치의 사용이 빈번해졌다. 통상적으로 사용하는 아크릴릭 레진과 비교했을 때 열가소성 레진은 낮은 굴곡 강도와 탄성률을 가지고 있다. 그러므로 열가소성 레진으로 제작된 가철성 장치는 파절의 위험이 낮아 의치상이 얇고 가볍게 만들어져 환자들이 편하게 사용할 수 있다. 또한 장치가 치아 언더컷에 수동적으로 장착될 수 있어 지대치의 삭제가 최소이거나 거의 없다. 이 증례에서는 경도의 구개인두부전을 가진 44세 여환은 polyester 계열 열가소성 레진으로 제작된 구개거상장치로 치료를 받았다. 환자가 결손치가 없고 보존적인 치료를 원하기 때문에 열가소성 레진을 이용한 가철성 장치가 상대적으로 만족스러운 치료 결과를 보였다.

• 구강회복응용과학지
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• 제24권4호
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• pp.325-335
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• 2008

연성 이장재를 의치에 적용했을 때, 의치 변연부에서 나타나는 공극에 의한 문제점을 많이 경험하게 된다. 그래서 변연 공극을 최대한 줄일 수 있는 방법을 연구하여야 하고 특히 최종 과정인 마무리와 연마시의 변연 공극의 양상에 대한 평가가 이루어져야 한다. 본 연구에서는 실리콘 계열의 연성 이장재인 $Molloplast-B^{(R)}$를 적용하였을 때, 의치와 연성 의치 이장재의 접합부에서 나타나는 공극의 양을 측정하고 연마 방법, 연마 방향이 변연 공극에 미치는 영향에 대하여 알아보고자 하였다. 마무리 방법과 연마 방법, 방향에 따라 군 분류를 하였고, 시편의 일관성과 정확성을 위해 금속 틀을 방전 가공하여 제작하였고, 제조사의 지시에 따라 총 50개의 시편을 제작하였다. 공극의 양은 120배 확대의 입체 광학 현미경상에서 가장 큰 값을 가지는 부위를 측정하였고, 모든 측정치는 통계적 분석, 평가 하였다. 실험 결과, 각 분류에 따른 공극을 비교 했을 때, $Molloplast^{(R)}$-Cutter로 마무리 한 후 pumice와 tin oxide를 순행하여 연마를 한 경우가 가장 크게 나타났고, FSQ-cross cut bur를 이용하여 마무리만 한 것이 가장 적게 나타났다. 또한 연마를 할수록 공극의 양이 증가되는 양상을 나타내었다. 방향에 따라서는 통계적 유의성은 나타나지 않았으나 레진에서 연성 이장재 방향으로 시행하였을 때가 더 적은 값을 나타내는 경향을 보였다. 이상의 결과로 보아 삭제력이 우수한 버일수록 레진과 연성 이장재의 접합부에서 나타나는 공극이 커짐을 알 수 있었고, 또한 연마를 시행 할수록 공극의 양이 유의성 있는 차이를 나타내었다. 접합부에서의 공극을 줄일 수 있는 마무리와 연마 방법에 대한 더 많은 연구가 이루어져야 하고 부가적으로 최종 연마가 끝나고 공극을 막아 줄 수 있는 재료에 대한 연구가 필요한 것으로 사료된다.