• Restorative Dentistry and Endodontics
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• 제34권2호
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• pp.113-119
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• 2009

본 연구의 목적은 다른 표면 젖음성을 갖는 상아질에 대한 수종의 자가접착레진시멘트의 인장접착강도를 비교하고자 하는 것이다. 이번 실험을 위해 Rely-X Unicem (3M, ESPE, St. Paul, MN, USA), Embrace Wetbond (Pulpdent, Oakland, MA, USA), Maxcem (Kerr, Orange, CA, USA) 3 종의 자기접착레진시멘트를 사용하였다. 발거한 상, 하악 대구치 60개를 미세절단기 (Acutom P-50, Struers, Copenhagen, Benmark)를 이용해 한 치아에서 $2mm{\times}2mm{\times}7mm$의 치아 시편 두개씩 얻었다. 상아질 표면을 건조 그룹은 10초간 강한 공기로 건조시켰고, 습윤 그룹은 과잉의 수분을 2 초간 거즈로 압박해 제거하였다. 상아질 표면의 젖음성을 달리한 시편에 자가접착레진시멘트를 접착한 후 상온의 상대습도 100% 상태에서 24시간 보관했고, 만능시험기 (EZ Test, Shimadzu corporation, Kyoto, Japan)를 이용해 인장접착강도를 측정했고, 분리된 접착면의 파절양상을 근관 치료용 현미경 (OPMI pro, Carl Zeiss, Oberkochen, Germany)을 이용해 20 배의 배율로 관찰하였다. $SPSS^{TM}$ Ver 10.0 (SPSS Inc., Chicago, IL, USA)을 사용하여 동일한 자가접착레진시멘트에서 상아질 젖음성에 따른 인장접착강도를 T-test로 비교하였으며, 각 자가접착레진시멘트간의 인장접착강도를 One way ANOVA test로 비교 분석하고 95% 유의수준에서 Scheffe's test로 사후검정 하였다. 실험 결과 자가접착레진시멘트의 인장접착강도는 상아질 젖음성에 영향을 받지 않았으며, 상아질 표면 젖음성과 상관없이 Maxcem의 인장접착강도가 Unicem과 Embrace의 인장접착강도보다 유의성 있는 낮은 값을 나타내었다. 또한 모든 시편의 분리된 접착면은 접착실패 양상을 나타내었다. 이상의 실험 결과로 볼 때 자가접착레진시멘트는 상아질 표면 젖음성에 상관없이 사용할 수 있을 것이라고 생각된다.

• Restorative Dentistry and Endodontics
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• 제35권2호
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• pp.106-115
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• 2010

본 연구는 간접 복합레진 수복물을 1종의 자가부식형 레진시멘트와 3종의 자가접착형 레진시멘트를 이용하여 상아질에 합착하였을 때 각 레진시멘트의 미세인장 결합강도와 결합계면의 차이를 평가하기 위하여 시행하였다. 발거된 상.하악 대구치 교합면 측 상아질에 Tescera 복합레진 블록을 레진시멘트(PA 군: Panavia F 2.0, RE 군: RelyX Unicem Clicker, MA 군: Maxem, BI 군: BisCem)를 이용하여 합착하였다. 증류수에 24시간 동안 보관한 후, 합착된 면의 단면적이 $1.0\;{\times}\;1.0\;mm$인 막대모양의 시편을 제작하여 각 시편에 분당 0.5 mm의 crosshead speed로 인장하중을 가하였다. 각 군의 미세인장 결합강도는 one-way ANOVA와 Tukey의 HSD 방법을 이용하여 비교하였다. FE-SEM 하에서 모든 파절편의 상아질 쪽 파절양상과 레진시멘트-상아질 및 레진시멘트-복합레진의 계면을 관찰하였다. 본 연구의 결과 간접 복합레진 블록을 레진시멘트로 상아질에 합착할 때 PA 군과 RE 군은 MA 군과 BI군보다 높은 결합강도와 긴밀한 접착 및 레진테그가 관찰되었고, 복합레진과 레진시멘트 간에는 간극이 관찰되었다.

• 대한치과의사협회지
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• 제50권7호
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• pp.377-383
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• 2012

Recently, ceramic materials have become a popular choice for dentists performing esthetic indirect restorations. The longevity and success of ceramic dental restorations depends on the adhesive procedures of resin cements. However, dental ceramics can be classified in various ways, depending on the compositions. Also, the applications for resin cement require multiple clinical steps. Therefore, understanding the different ceramic substrates involved in each procedure, as well as the proper adhesive steps for the resin cements is important to us for long-term clinical success.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.877-882
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• 1998

Concrete structure placed in marine environment is subject to many different types of potential attack. Therefore the sea water resistance of cement and concrete must be considered when it is used for structure in the ocean. For this purpose, this study was peformed to investigate the properties of several types of cements for a massive concrete placed in marine environment.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.373-378
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• 1996

This paper presents the characteristics of various strengths of underwater non-segregation concrete. Three types of cements including low-heat cements has been used to make the test specimens for compressive strength, modulus of rupture and bond strength. The test specimens have been made both in ambient and underwater conditions to take into account the variation according to the environmental condition.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.163-169
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• 1997

The sea water resistance of cement and concrete must be considered when it is used for construction on the seashore of in the ocean. The concrete specimens using seven type of cements such as ordinary Portland cement, moderate heat Portland cement, sulfate resistance Portland cement, type A. B. C Portland blastfurnace slag cement and Portland flyash cement were immersed for 10 years in seawater in Kunsan. This study proved that moderate heat Portland cement, sulfate resistance Portland cement, type A Portland blastfurnace slag cement had higher resistance for seawater.

• 대한치과보철학회:학술대회논문집
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• 대한치과보철학회 1998년도 춘계학술대회
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• pp.22-22
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• 1998

• The Journal of Advanced Prosthodontics
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• 제9권2호
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• pp.130-137
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• 2017

PURPOSE. The purpose of this study was to evaluate the effect of nano-structured alumina surface coating on shear bond strength between Y-TZP ceramic and various dual-cured resin cements. MATERIALS AND METHODS. A total of 90 disk-shaped zirconia specimens (HASS CO., Gangneung, Korea) were divided into three groups by surface treatment method: (1) airborne particle abrasion, (2) tribochemicalsilica coating, and (3) nano-structured alumina coating. Each group was categorized into three subgroups of ten specimens and bonded with three different types of dual-cured resin cements. After thermocycling, shear bond strength was measured and failure modes were observed through FE-SEM. Two-way ANOVA and the Tukey's HSD test were performed to determine the effects of surface treatment method and type of cement on bond strength (P<.05). To confirm the correlation of surface treatment and failure mode, the Chi-square test was used. RESULTS. Groups treated with the nano-structured alumina coating showed significantly higher shear bond strength compared to other groups treated with airborne particle abrasion or tribochemical silica coating. Clearfil SA Luting showed a significantly higher shear bond strength compared to RelyX ARC and RelyX Unicem. The cohesive failure mode was observed to be dominant in the groups treated with nano-structured alumina coating, while the adhesive failure mode was prevalent in the groups treated with either airborne particle abrasion or tribochemical silica coating. CONCLUSION. Nano-structured alumina coating is an effective zirconia surface treatment method for enhancing the bond strength between Y-TZP ceramic and various dual-cured resin cements.

• The Journal of Advanced Prosthodontics
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• 제9권2호
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• pp.77-84
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• 2017

PURPOSE. The aim of this study was to compare the surface roughness of zirconia when using Zircos E etching system (ZSAT), applying a nitric acid-hydrofluoric acid compound as a pretreatment agent, and also to compare the shear bonding strength according to different resin cements. MATERIALS AND METHODS. ZSAT, air abrasion, and tribochemical silicacoating were applied on prepared 120 zirconia specimens (10 mm in diameter, 7 mm in height) using CAD/CAM. Each 12 specimens with 4 different resin cements (Panavia F 2.0, Rely X Unicem, Superbond C&B, and Hot bond) were applied to test interfacial bond strength. The statistical analysis was performed using SAS 9.1 (SAS Institute Inc., Cary, NC, USA). The results are as follows: after application of the ZSAT on the zirconia specimens, surface roughness value after 2-hour etching was higher than those after 1- and 3-hour etching on SEM images. RESULTS. For Superbond C&B and Rely X Unicem, the specimens treated with ZSAT showed higher shear bond strength values than those treated with air abrasion and tribochemical silicacoating system. Regarding the failure mode of interface over cement and zirconia surface, Rely X Unicem and Hot bond showed cohesive failures and Panavia F 2.0 and Superbond C&B showed mixed failures. CONCLUSION. Zircos E etching system in zirconia restoration could increase its shear bond strength. However, its long term success rate and clinical application should be further evaluated.

• The Journal of Advanced Prosthodontics
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• 제8권3호
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• pp.201-206
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• 2016

PURPOSE. The aim of this study was to compare the radiopacity of 6 modern resin cements with that of human enamel and dentine using the Digora digital radiography system, to verify whether they meet the requirements of ANSI/ADA specification no. 27/1993 and the ISO 4049/2000 standard and assess whether their radiopacity is influenced by the thickness of the cement employed. MATERIALS AND METHODS. Three 3-thickness samples (0.5, 1 and 1.5 mm) were fabricated for each material. The individual cement samples were radiographed on the CCD sensor next to the aluminium wedge and the tooth samples. Five radiographs were made of each sample and therefore five readings of radiographic density were taken for each thickness of the materials. The radiopacity was measured in pixels using Digora 2.6 software. The calibration curve obtained from the mean values of each step of the wedge made it possible to obtain the equivalent in mm of aluminium for each mm of the luting material. RESULTS. With the exception of Variolink Veneer Medium Value 0, all the cements studied were more radiopaque than enamel and dentin (P<.05) and complied with the ISO and ANSI/ADA requirements (P<.001). The radiopacity of all the cements examined depended on their thickness: the thicker the material, the greater its radiopacity. CONCLUSION. All materials except Variolink Veneer Medium Value 0 yielded radiopacity values that complied with the recommendations of the ISO and ANSI/ADA. Variolink Veneer Medium Value 0 showed less radiopacity than enamel and dentin.