침엽수단판의 수지함침처리에 의한 압밀화 특성

서진석 한국가구학회 2003 한국가구학회지 Vol.14 No.2

This study was carried out to investigate characteristics of plywood overlaid with softwood veneers densified by resin impregnation and compression. The resin impregnability of Korean pine veneer under atmospheric pressure soaking was greater than that of larch, and impregnability of melamine resin was slightly greater than phenolic resin. It was suggested that resin impregnation ratio was affected by density and thickness of veneer. The largest melamine resin impregnation ratio of 50.7% was obtained with 1.26mm thick Korean pine veneer, and the lowest phenolic resin impregnation ratio of 11.7% with 3.41mm thick larch veneer. Therefore, it was suggested that the vacuum-pres sure-soak treatment is required at thick larch veneer. In densifying resin-impregnated veneers, densification ratio from 13.4 to 31.2% was obtained by high pressure from 15.6 to $20.8kgf/cm^2$. Impregnation of melamine resin also showed relatively greater at densification than that of phenolic resin. So it showed the degree of densification of about 20% or greater. It was seemed that adhesive bonding strength of plywood(base panel) which was directly pressed and overlaid with resin-impregnated veneer was affected by resin tackiness after resin impregnation followed by semi-drying. In laboratory scale, melamine resin impregnation was more favorable for the development of adhesive bonding strength owing to moisture control.

Resin infiltration을 시행한 법랑질 초기 우식 병소의 특성

김은영,권민석,김신,정태성 大韓小兒齒科學會 2012 大韓小兒齒科學會誌 Vol.39 No.1

The concept of resin infiltration which was born in an innovative philosophy to arrest the incipient caries. However, the structural changes of resin infiltrated lesions have not yet explained completely. The liquid resin might contribute not only to maximizing the penetration but to deteriorating physical stability. This study was performed to examine some physical and histological features of resin infiltrated incipient carious lesions. With the specimen of resin infiltrated lesions, microhardness by nanoindentation in depth profile, morphology of resin tags were revealed after HCl dissolution, and degree of microleakage were assessed. The percentage of microhardness of surface layer and lesion body of untreated specimen to sound enamel was 64.6% and 24.6% respectively, while that of resin-infiltrated lesions was 72.1%, showing significant difference (p<0.05). The resin tags observed under SEM had relatively homogeneous length of 433(282~501) ㎛ on the average. Among 20 specimens for microleakage assessment, 13 specimens showed no leakage while 5 and 2 showed leakage into outer and inner half of lesion respectively. It was thought the infiltrant resin penetrates deeply and homogeneously into lesion body and improves its hardness with relatively good physical stability. 본 연구는 infiltrant resin을 침투시킨 초기 우식 병소의 특성을 평가하기 위해 법랑질의 깊이에 따른 경도를 측정하고, 병 소 내로의 레진 침투양상을 분석하며, 미세누출 정도를 관찰하여 다음의 결과를 얻었다. 건전 법랑질에 대한 초기 우식 법랑질의 경도 백분율은 표층(5~40 ㎛) 64.6%, 병소본체(60~350 ㎛) 24.6%였으며, infiltrant resin을 침투시킨 병소의 경도 백분율은 72.1%로 나타났다. 5~350 ㎛의 전 깊이에서, infiltrant resin을 침투시 킨 병소는 비처치 우식 병소보다 경도가 유의하게 높았지만 정상 법랑질에 비해서는 경도가 유의하게 낮았다(p<0.05). FESEM 관찰 결과 탈회된 법랑질 내부로 비교적 균일하게 침투한 레진 테그가 관찰되었으며, 침투깊이는 433 ㎛(282-501)로 측정되었다. 열순환 처리 후 13개의 치아에서 미세누출이 관찰되지 않았고, 5개에서 병소 외측 절반, 2개에서 병소 내측 절 반까지 미세누출이 관찰되었다.

OCT 광학기기의 레진 컴파짓 수복평가의 응용

Sang Mi Jeon,Young Hee Lee,Hyeong Joon Ji,Hye Joung Cho,Seo Jin Kim,Hye Eun Kim,SUN QIAOCHU,Kyu Hyeon Ahn,Hong Ran Choi,Ok Joon Kim 대한구강악안면병리학회 2016 대한구강악안면병리학회지 Vol.40 No.4

Composite resins are developed as restorative materials to improve esthetics and mechanical properties. To improve the physical properties of resin material, resin filler have to be added. However, no imaging method is adopted for resin filler distribution. Optical coherence tomography (OCT) is a optical imaging technique to delineate microscopic structures within biological tissue. The OCT application to dental composites resin and its filler is not described yet. So, this new and advanced optical method is needed for clinical application for evaluation of dental composite resin. To analyze the spatial distribution of dental composite resin and to evaluate the resin restoration in cavity, frequency domain optical coherence tomography (FD-OCT) was used for their analysis. Resin restored tooth was prepared. For morphological observation, serially sectioned teeth, conventional X-ray taking and micro computed-tomography (CT) images were compared with OCT images. The experiment has done to evaluate the success of the resin restoration using 3 dimensional structure OCT image. In this research, OCT is evaluated as a new technique to image resin restoration. The evaluation of resin restored tooth was performed by OCT. Inappropriate restoration such as marginal adaptation, large porosities, internal integrity and poor contour could be detected. Resin filler also could be checked by OCT. The distribution, number, regularity and size of resin filler can be differentiated from several commercial products. Considering the characteristics of the OCT, it can be used to evaluate the defects of resin restoration, resin filler distribution, and internal integrity between resin material and tooth structure. The OCT can be considered to be a new and advanced method for the evaluation of resin restorations.

A STUDY OF MICROHARDNESS AND POLYMERIZATION SHRINKAGE OF PACKABLE RESINS

Son, Deok-Il,Nam, Soon-Hyeun,Kim, Hyun-Jung,Seol, Hyo-Joung,Kwon, Yong-Hoon,Kim, Hyung-Il,Kim, Young-Jin 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.3

Packable resin은 아말감을 대신할 수 있을 것이라는 기대와 함께 상용화되었다. 이런 packable resin은 종래의 hybrid resin과는 달리 필러함량이 높고 분포가 더 조밀하다. 본 연구에서는 높은 필러함량이 packable resin의 미세경도와 경화수축에 미치는 영향을 조사하고 그 결과들을 hybrid resin에서 얻은 것들과 비교하였다. 그 결과 packable resin은 hybrid resin에 비하여 보다 높은 미세경도를 보였는데 본 실험에 사용된 레진들은 종류에 관계없이 그들의 미세경도가 필러함량 (vol%)과 상관관계가 있었다. 또한 packable resin은 hybrid resin에 비하여 훨씬 적게 경화수축 하였는데 관찰된 경화수축과 필러함량 사이에는 역상관관계가 있었다. Packable resins have been introduced in the market with high expectations as an alternative to amalgam. They are characterized by a high-filler load and a filler distribution that gives them a different consistency compared with the hybrid resins. The effect of high filler load on the microhardness and polymerization shrinkage of packable resins was tested. Hybrid resins were also tested to compared with the packable resins. As a result, packable resins showed a much greater microhardness value than hybrid resins. All the tested resins have a correlationship with the microhardness and filler content (vol%). The packable resins showed much less polymerization shrinkage than hybrid resins. The filer content and polymerization shrinkage were inversely correlated in the tested resins.

가압주사식 열가소성 의치상 레진과 이장 레진 간의 결합강도에 관한 연구

문태성,정창모,전영찬,임장섭,Moon Tae-Sung,Jeong Chang-Mo,Jeon Young-Chan,Lim Jang-Seop 대한치과보철학회 2002 대한치과보철학회지 Vol.40 No.1

The purpose of this study was to evaluate the bond strength of reline resin to pressure injection type thermoplastic denture base resin. The denture base resins used in this study were $Hi-polycarbonate^{(R)}$(High Dental Co., Japan), Acetal $dental^{(R)}$(Pressingdental s.r.1., Repubblica di San Marine) of thermoplastic resin and Acron $MC^{(R)}$(GC Dental Industrial Co., Japan) of heat cured resin. The reline resins used were Lucitone $199^{(R)}$(Dentsply international Inc., USA), Tokuso $rebase^{(R)}$(Tokuyama Corp., Japan), and $Lightdon-U^{(R)}$(Dreve-Dentamid-Gmbh, Germany). The reline resins are representative of heat-cured, self-cured, and light-cured resin respectively Bond strength was examined by use of a three-point transverse flexural strength test. The results were as follows 1. The bond strength of Lucitone 199 to Acron MC was the highest. 2. The bond strengths of Lucitone 199 and Tokuso rebase to Hi-polycarbonate resulted in a value of approximately one half that of Lucitone 199 to Acron MC and there were no significant differences between these and the bond strength of Tokuso rebase to Acron MC(p<0.05) 3. The bond strengths of reline resins to Acetal dental were lower than those of reline resins to Hi-polycarbonate. 4. For all base resins Lightdon-U showed lower bond strength than the other reline resins.

Evaluation of the Color Adjustment Potential of Single-Shade Composite Resin in Primary Teeth

김용순,박호원,이주현,김해니,Yongsoon Kim,Howon Park,Juhyun Lee,Haeni Kim Korean Academy of Pediatric Dentistry 2023 大韓小兒齒科學會誌 Vol.50 No.1

Restoring composite resins with the optimal shades for all primary teeth is a great challenge for pediatric dentists. A newly developed single-shade composite resin can exhibit a color similar to that of the surrounding tooth structure based on the structural color phenomenon. This study aims to evaluate the color adjustment potential (CAP) of a single-shade composite resin compared to conventional multi-shade composite resins in primary teeth. A single-shade composite resin and two conventional multi-shade composite resins were included in this study. Two types of specimens, a single specimen and a dual specimen, were evaluated. For single specimens, duplications of the primary second molar denture teeth were made using experimental composite resins. For dual specimens, cavities were prepared on the buccal surfaces of extracted primary second molars and restored with experimental composite resins. The L^*, a^*, and b^* values were measured using a colorimeter for the extracted teeth and specimens. The mean ΔE_ab^* values for single and dual specimens and CAP were calculated. Bonferroni post-hoc analysis was performed to confirm the statistical significance between the ΔE_ab^* and CAP values of the experimental resins. Among the single specimens, the single-shade composite resin showed significantly higher ΔE_Single compared to other composite resins (p < 0.0167). There was no significant difference between ΔE_Dual for all experimental resins. The single-shade composite resin showed highest CAP compared to other multi-shade composite resins. A single-shade composite resin exhibited the most prominent color adaptability compared to other conventional multi-shade composite resins for primary second molars. A single-shade composite resin can simplify shade matching and provide esthetic outcomes for the restoration of primary second molars.

열중합 레진과 열가소성 레진틀니 제작방법에 관한 연구

남관우 ( Nam Gwan-woo ) 한국융합과학회 2018 한국융합과학회지 Vol.7 No.3

연구목적: 본 연구는 열중합 resin의 수축으로 인한 교합 및 접합 불량과, 기포에 음식물이 침투하여 부패하고 이로 인한 박테리아 번식 및 악취와, resin에서 잔류 모노머 용출로 인해 인체에 위해한 문제가 발생 하는 요인을 규명하고 개선하는데 주된 목적이 있다. 연구방법: 통상적인 중합형 레진(polymerization resin)의 액과 분말을 섞어서 조작하여 떡상의 레진을 몰드 내에 밀어 넣고 시험폐쇄(trial closure)후 압력을 가하며 중합하는 방법과, 열가소성 레진(thermoplastic resin)을 열과 압력 하에서 연화시켜 주입구를 통해 빈 몰드 안에 밀어 넣어 성형하고 냉각하면, 화학적 변화 없이 경화되어 성형된 상태를 유지하는 사출 방식의 denture 제작 방법을 비교하며 분석 하였다. 결론: 연구결과는 다음과 같다. 첫째, 중합수축 문제를 해결하여 수축으로 인한 변형이 없어 구강 조직에 편안하게 잘 맞으며 교합 또한 안정적인 틀니를 제공 할 수 있다. 둘째, 틀니의 수축기포를 해결하여 기포사이에 음식물이 침투하여 부패하고 이로 인해 박테리아가 번식하여 악취가 나는 틀니의 오염과 비위생적인 문제를 해결할 수 있다. 셋째, 틀니를 사용하는 상당기간 동안 용출하는 잔류모노머가 없어 인체에 악영향을 미치는 것을 예방할 수 있다. 넷째, 주입기에서 몰드로 주입시킨 후 냉각하면 되므로 작업시간 단축과 간편성은 중합수축을 줄이려고 개발되어진 여러 가지 공법들을 하나의 사출시스템으로 해결할 수 있어 획일적인 작업이 가능하다. Pupose: When the thermoplastic resin(thermoplastic resin) by softening under heat and pressure to mold and cooled and molded to research a manufacturing method of a Denture for holding the molded cured state was obtained without any chemical change in this result. Methods: A method of mixing a liquid and a powder of a polymerization resin and then pouring the resin in a mold into a mold and performing a trial closure and then applying a pressure to the mixture to polymerize the thermoplastic resin; The molds were softened and injected into the empty mold through the injection port. The molded and cooled molds were compared and compared with the injection molding denture manufacturing method which kept the molded state without chemical change. Conclusion: The results of the study are as follows. First, it solves the polymerization shrinkage problem, and it is not deformed due to contraction, so it can fit comfortably in the oral tissues and can provide a stable denture for occlusion. Second, it can solve pollution and unhygienic problems of dentures, which dissolve the contraction bubbles of the dentures and become contaminated by the food penetration between the bubbles, which causes the bacteria to reproduce. Third, there is no residual monomer eluting for a considerable period of time using the denture, and adverse effects on the human body can be prevented. Fourth, since injector injects into molds, it can be cooled. Therefore, it is possible to accomplish uniform work by shortening work time and simplifying various methods that have been developed in order to reduce polymerization shrinkage by using one injection system.

Effects of Reaction pH and Hardener Type on Reactivity, Properties, and Performance of Urea-Formaldehyde (UF) Resin

Byung-DaePark,김윤수,임기표,소원택 한국목재공학회 2002 목재공학 Vol.30 No.3

This study was conducted to investigate the effects of reaction pH conditions and hardener types on the reactivity, chemical structure and adhesion performance of UF resins. Three different reaction pH conditions, such as traditional alkaline-acid (7.5 → 4.5), weak acid (4.5), and strong acid (1.0), were used to synthesize UF resins which were cured by adding three different hardeners (ammonium chloride, ammonium citrate, and zinc nitrate) to measure adhesion strength. Fourier transform infrared (FT-IR) and carbon-13 nuclear magnetic resonance (13C-NMR) spectroscopies were employed to study chemical structure of the resin prepared under three different reaction pH conditions. Adhesion strength of the resins cured with three different hardeners was determined with lap shear specimens in tension. The gel time of UF resins decreased with an increasing in the amount of both ammonium chloride and ammonium citrate added in the resins. However, the gel time increased for zinc nitrate. Both FT-IR and 13C-NMR spectroscopies showed that the strong reaction pH condition produce uronic structures in UF resin, while both alkaline-acid and weak acid conditions produce quite similar chemical species in the resins. The maximum adhesion strength was occurred with the resin prepared under strong acid pH condition. However, this study indicated that the weak acid reaction condition provide a balance between increasing resin reactivity and improving adhesion strength of UF resin. The measurement of formaldehyde emission from the panels bonded with the UF resins prepared is planned for future work.

Acrylic Resin에 혼합된 Polyphosphate가 미생물의 부착 및 성장에 미치는 영향

홍선희,최영철,Hong, Sun-Hee,Choi, Yeong-Chul 대한소아치과학회 2003 大韓小兒齒科學會誌 Vol.30 No.1

자가중합형 아크릴릭 레진에 polyp를 혼합하지 않은 대조군, 그리고 레진 분말에 대한 polyP(사슬길이 13과 18의 혼합물인 Calgon)의 무게비를 1%로 혼합한 polyP 1%군, 2% 혼합한 polyP 2%군 및 3% 혼합한 polyP 3%군으로 분류하여 경화시킨 후, 경화된 각각의 레진과 실험균주 S. mutans GS5, S. sobrinus 6715, S. gordonii G9B및 Challis, 그리고 P. gingivalis 2561과 Candida albicans ATCC90027을 대상으로 레진표면에 대한 미생물들의 부착의 정도, 성장 억제효과 및 접촉각의 변화를 관찰하여 그 결과로 미루어 아크릴릭 레진에 포함된 polyP는 구강 미생물에 대해 직접적으로 강한 항균 효과를 나타내지는 않는 것으로 판단되나 미생물의 부착 특히 우식원인균인 mutans streptococci의 부착을 방해하는 것으로 가늠되며, 이는 polyP의 첨가에 의한 아크릴릭 레진 표면에서 일어난 소수성의 변화가 일부 관여하는 것으로 여겨진다. PolyP가 혼합된 아크릴릭 레진의 장착은 일반적인 아크릴릭 레진으로 제작된 가철성 장치를 장착한 후 나타날 수 있는 우식 이환의 가능성을 감소시킬 수 있는 임상적 적용 가능성을 제시하였다고 여겨진다. The purpose of this present study was to develop a new way of self-curing acrylic resin, using commercially available polyphosphate, Calgon, which is known to be antimicrobial and safe. For the study, polyphosphate(polyP) was blended with acrylic powder and devided into four groups as follows: no polyP(control), 1% polyP, 2% polyP, and 3% polyP. For the experiment, Streptococcus mutans GS5, Streptococcus sobrinus 6715, Streptococcus gordonii G9B and Challis, Porphyromonas gingivalis 2561, and Candida albicans ATCC 90027 were used. Resin specimens in each group were tested in vitro for the purpose of investigating the effect of polyP on the microbial attachment, growth and hydrophobicity of the resin surface. The results were as follows. 1. PolyP added to the acrylic resin decreased attachment of S. mutans GS5, S. sobrinus 6715, S. gordonii G9B. The greater binding inhibition was found in acrylic resin polymerized with polyP at higher concentrations. 2. The addition of polyP to acrylic resin failed to significantly affect the growth of the tested microorganisms. 3. The addition of polyP to acrylic resin seemed to reduce hydrophobicity of the acrylic resin. PolyP in acrylic resin does not seem to exert a direct antibacterial activity, but rather inhibit attachment of oral bacteria, especially mutans streptococci to saliva-coated acrylic resin. The acrylic resin reduces attachment of streptococci may be due to the decreased hydrophobicity caused by polyP added to the resin. PolyP may be included to acrylic resin to inhibit dental caries which often occurs when removable acrylic resin appliance is placed.

Effect of Synthesis Method and Melamine Content of Melamine-Urea-Formaldehyde Resins on Bond-Line Features in Plywood

( Muhammad Adly Rahandi LUBIS ),( Bora JEONG ),( Byung-Dae PARK ),( Sang-Min LEE ),( Eun-Chang KANG ) 한국목재공학회 2019 목재공학 Vol.47 No.5

This work examined effects of the synthesis method and melamine content of melamine-urea-formaldehyde (MUF) resins on the bond-line features (i.e. resin penetration and bond-line thickness) in plywood. Two synthesis methods (MUF-A and MUF-B) and three melamine contents (5, 10, and 20%) were employed to prepare MUF resins. The MUF-A resins at three melamine contents were prepared by a simultaneous reaction of melamine, urea, and formaldehyde, while the MFU-B resins were prepared by reacting melamine at the same levels with formaldehyde followed by urea. The results showed that higher melamine content increased the viscosity of MUF-A and MUF-B resins. The resin penetration of MUF-A resins decreased by 48% while those of MUF-B resins increased by 16% at 20% melamine content. As a result, the MUF-A resins had greater bond-line thickness than those of MUF-B resins as the melamine content increased. The MUF-B resins resulted in thinner bond-line and greater resin penetration compared to those of MUF-A resins. The results suggested that MUF-B resins prepared with 20% melamine content had a proper combination of resin penetration and bond-line thickness that could produce plywood panel with a better adhesion performance.