• Restorative Dentistry and Endodontics
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• 제13권2호
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• pp.207-220
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• 1988

The purpose of this study was to measure roughness on the polished surfaces of composite resin, and was to observe the polished surfaces under Scanning Electron Microscope. The surface roughness tester (Surfcom 700A Semitsu Profilometer Tokyo. Japan) was used to measure roughness of polished surfaces. In this study, 4 brands of composite resin were examined, Pyrofil bond anterior Bell-Feel anterior Clearfil F II and Microrest A.P. White point, Silicone point, Super snap, and Sof-Lex medium disc as cutting instrument, and celluloid matrix were used. The results obtained were as follows. 1) The celluloid matrix produced the smoothest surfaces. 2) Microrest composite resin had smoother surface than any other composite resins after polishing. 3) The values of surface roughness made by White point, Silicon point and Super snap were similar. 4) The surfaces made by Sof-Lex medium disc was smoother than the surfaces made by any other polishing instruments.

• 대한전기학회논문지
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• 제41권6호
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• pp.640-651
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• 1992

This paper describes the electric properties of mica reinforced silicone composites with the parameter of curing condition of silicone resin, application amount of silane coupling agent to the mica paper and the mica wt% to the composite. Heat-resistant silicone resin and mica paper made of mica flakes are used to prepared the mica/silicone composite as matrix and filler, respectively. To improve the dielectric properties and interfacial adhesion between matrix and filler, silane coupling agent is applied on the mica paper. As for matrix, tan$\delta$ value of 30$0^{\circ}C$ heat-treated silicone resin is the lowest under 1%. The optimal wt% of coupling agent is 0.3% to the weight of mica paper. 80 wt% of mica as filler to the mica/silicone composite shows the best electric properties. And the mica reinforced silicone composite shows good high-frequency and mechanical tensile stress properties.

• 대한심미치과학회지
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• 제27권2호
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• pp.66-74
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• 2018

2급와동의 복합레진수복은 강한 컨택과 적절한 외형 형성이 쉽지 않은 치료술식이다. 이를 극복하기 위해 고안된 매트릭스 시스템들이 있으나, 이에 대해 익숙하지 않은 술자들은 여전히 어려움을 겪곤한다. 이에 쉽고 효율적으로 성공적인 결과를 얻을 수 있는 테크닉을 필요하다. 본 케이스 리포트에서는 2급 와동의 복합레진수복술식을 과정별로 설명하고, 쉽고 간단히 만족할 만한 결과를 얻을 수 있는 원칙들과 임상팁들을 설명하였다.

• 대한치과재료학회지
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• 제44권4호
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• pp.311-318
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• 2017

본 연구의 목적은 2가지 임시 수지 (Bis-acryl resin composite 및 polymethyl methacrylate (PMMA))의 굴곡 강도 및 미세 경도에 대한 경화 순서 및 중합 온도의 영향을 조사하는 것에 있다. 중합은 대기 중 $25^{\circ}C$ (대조) 및 온수 (40, 50, 60, 70 그리고 $80^{\circ}C$)에서 다양한 조건하에 수행되었다. 굴곡 강도 시험은 ISO-4049에 따라 수행되었다. 또한, 누프 경도를 측정 하였다. Bis-acryl resin의 경우, $50^{\circ}C$까지의 온도는 굴곡 강도와 bis-acryl resin composite의 경도를 증가시키지 않았지만 (p> 0.05), 온도가 높을수록 강도가 증가 하였다. PMMA 수지의 경우 굴곡 강도는 최대 $70^{\circ}C$의 온도에서 증가하고 약간 감소합니다. Bis-acryl resin은 PMMA 수지보다 기계적 특성이 더 컸다. 열의 영향은 Bis-acryl resin에서 PMMA 수지보다 더 두드러졌다(p <0.05).

• 구강회복응용과학지
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• 제26권4호
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• pp.447-453
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• 2010

본 연구에서는 할로겐 광원의 빛이 복합레진의 색상과 두께에 따라 어느 정도 투과가 되는지를 비교하고자 Z-250 복합레진 (3M ESPE, St. Paul, U.S.A.)의 A1, A2, A3 색상에서 2, 3, 4 mm 로 두께를 달리한 뒤 밑면에서 복합레진 본체와 차단된 복합레진 시편의 중합도를 FTIR spectroscopy로 측정하였다. 그 결과 색상이 어두워질수록 할로겐 광원의 투과능력은 감소하였으며 두께가 두꺼워질수록 할로겐 광원의 투과능력이 감소하였다. 위의 결과를 바탕으로 할로겐 광원을 이용하는 중합도를 향상시키기 위해서는 복합레진의 색상을 밝은 것으로 이용하며 가급적 얇은 두께로 복합레진을 충전하여야 할 것으로 사료된다.

• Restorative Dentistry and Endodontics
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• 제29권4호
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• pp.353-364
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• 2004

The purpose of this study was to compare and to evaluate the combination use of 5 kinds of dentin adhesive systems and 5 kinds of composite resins using micro-shear bond test. Five adhesive systems (Prime & Bond NT (PBN). Onecoat bond (OC), Excite (EX), Syntac (SY), Clearfil SE bond (CS)) and five composite resins (Spectrum (SP), Synergy Compact (SC), Tetric Ceram (TC), Clearfil AP-X (CA), Z100 (Z1)) were used for this study ($5{\;}{\times}{\;}5{\;}={\;}25group$, n =14/group). The slices of horizontally sectioned human tooth were bonded with each bonding system and each composite resin, and tested by a micro-shear bond strength test. These results were analyzed statistically. The mean micro-shear bond strength of dentin adhesive systems were in order of CS (22.642 MPa), SY (18.368 MPa), EX (14.599 MPa). OC (13.702 MPa). PBN (12.762 MPa). The mean bond strength of self-etching primer system group (CS, SY) in dentin was higher than that of self-priming adhesive system groups (PBN, EX, OC) significantly (P<0.05). The mean bond strength of composite resins was in order of SP (19.008 MPa), CA (17.532 MPa). SC (15.787 MPa), TC (15.068 MPa). Z1 (14.678 MPa). Micro-shear bond strength of SP was stronger than those of other composite resins significantly (P < 0.05). And those of TC and Z1 were weaker than other composite resins significantly (P < 0.05). No difference was found in micro-shear bond strength of composite resin in self-etching primer adhesive system groups (CS, SY) statistically. However, there was significant difference of micro-shear bond strength of composite resin groups in self-priming adhesive systems group (PBN, EX, OC). The combination of composite resin and dentin adhesive system recommended by manufacturer did not represent positive correlation. It didn't seem to be a significant factor.

• 대한치과기공학회지
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• 제38권3호
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• pp.135-142
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• 2016

Purpose: The aim of this research was to evaluate the influence of different surface treatments on the shear bond strength of zirconia ceramic to composite resin. Methods: Seventy two cylinder-shape (diameter: 5 mm; height: 12 mm) blocks of experimental industrially manufactured Y-TZP ceramic were abraded with $125{\mu}m\;Al_2O_3$ particles and randomly divided into 4 groups. All the materials were categorized as group Gc(control group - composite resin veneering on zirconia surface), Gr - composite resin veneering after surface treatment of Rocatec system (3M ESPE, Seefeld, Germany) group; Gz - composite resin veneering after surface treatment of Zirconia primer (Z-primer, Bisco, U.S.A) group; Gm - composite resin veneering after surface treatment of zirconia primer (Monobond plus, ivoclar vivadent AG, Liechtenstein) group. Two different zirconia primers and Rocatec system were used to zirconia cylinders (n=16) onto the zirconia surface. Zirconia specimens, polished and roughened, were pretreated and composite bilayer cylinders bonded using conventional adhesive techniques. Results: Shear bond strengths were analyzed using single-factor ANOVA(p<0.05). Bond strength values achieved after airbone particle abrasion and zirconia surface pre-treatments(p<0.05). Conclusion: Shear bond strength tests denmonstrated that zirconia primer is a viable method to improved bond strength between zirconia ceramic core and veneering composites.

• 대한치과보철학회지
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• 제29권3호
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• pp.171-179
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• 1991

The purpose of this study was to investigate the color stability of 3 porcelain repair composite resins Twenty specimens of each composite resin were made and ten specimens were polished at 10 minutes after polymerization, and the others were polished at 48 hours after polymerization. For 60 days, the color characteristics were measured by fiber-optic colorimeter (Model Tc-6FX, Tokyo Denshoku Co.). The obtained results were as follows: 1. The changes of $a^*$ value and $b^*$ value in composite resin polished at 10min. after polymerization were greater than those of composite resins polished at 48 hrs. after polymerization. 2. The $a^*$ values of all composite resins were increased and the $b^*$ values were decreased. 3. The $L^*$ values were decreased in composite resin manufactured by K & B Co., which were polished at 10min. after polymerization, but increased in composite resin manufactured by K & M Co., polished at 48 hrs. after polymerization.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.35-60
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• 1997

Physical properties of composite resins such as strength, resistance to wear, discoloration, etc, depend on the degree of conversion of the resin components. The clinical behavior of restorative resins varies brand to brand. Part of this variation is associated with the filler and differences in the polymer matrix. The polymer matrix of resins may differ because the involved monomers are dissimilar and because of variation in the catalyst system. The purpose of this study was to evaluate the degree of conversion of the composite resins according to the depth of cure and light curing time. 7mm diameter cylindrical aluminum molds were filled with each of five different hybrid light curing composite resins(Z-100, Charisma, Herculite XRV, Prisma TPH, Veridonfil) on the thin resin films. The molds were 1mm, 2mm, 3mm, 4mm, and 5mm in depth to produce resin films of various heights. Each sample was given 20sec, 40sec, and 60sec illumination with a light source. The degree of conversion of carbon double bonds to single bonds in the resin films was examined by means of Fourier Transform Infrared Spectrometer. The results were obtained as follows; 1. There was difference in the degree of conversion among five light curing composite resins according to the depth of cure for 20sec, 40sec, and 60sec illumination with light source with statistical significance(P<0.05). 2. Five light curing composite resins show lower degree of conversion at surface of the resin than depth of 1mm. 3. The degree of conversion of five light curing composite resins was siginificantly reduced from the maximum for the resin film when the light passed through as little as 1mm of each composite. 4. The degree of conversion of five light curing composite resins decrease significantly at the depth of 4mm, and polymerization was not occured at the depth of 5mm except for Prisma TPH. 5. The degree of conversion of five light curing composite resins was increased with increased light curing time, and there was no significant differences in the degree of conversion above 4mm in Z-100, 3mm in Charisma, and at depth of 5mm in Herculite XRV and Veridonfil(P>0.05).

• 연구논문집
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• 통권29호
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• pp.151-162
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• 1999

In general, manufacturing processes of thermosetting composites consist of mold filling and resin cure. The important parameters used in modeling and designing mold filling are the permeability of the fibrous preform and the viscosity of the resin. To consolidate a composite, resin cure or chemical reaction plays an essential role. Cure kinetics. Therefore, is necessary to quantify the extent of chemical reaction or degree of cure. It is also important to predict resin viscosity which can change due to chemical reaction during mold filling. There exists a heat transfer between the mold and the composite during mold filling and resin cure. Cure kinetics is also used to predict a temperature profile inside composite. In this study, a new scheme which can determine cure kinetics from dynamic temperature scaning was proposed. The method was applied to epoxy resin system and was verified by comparing measurements and predictions.