• 대한치과보철학회지
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• 제38권3호
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• pp.366-374
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• 2000

FRC/ceromer system provides the clinician with a durable, flexible, and esthetic alternative to conventional porcelain fused to metal crowns. FRC is the matrix which is silica-coated and embedded in a resin matrix. The ceromer material which is a second generation indirect composite resin contains silanized, microhybrid inorganic fillers embedded in a light-curing organic matrix. FRC/ceromer restoration has a several advantages: better shock absorption, less wear of occluding teeth, translucency, color stability, bonding ability to dental hard tissues, and resiliency. It has versatility of use including inlay, onlay, single crown, and esthetic veneers. With adhesive technique, it can be used for single tooth replacement in forms of inlay adhesion bridge. In single tooth missing case, conventional PFM bridge has been used for esthetic restoration. However, this restoration has several disadvantages such as high cost, potential framework distortion during fabrication, and difficulty in repairing fractures. Inlay adhesion bridge with FRC/ceromer would be a good alternative treatment plan. This article describes a cases restored with Targis/Vectris inlay adhesion bridge. Tooth preparation guide, fabrication procedure, and cementation procedure of this system will be dealt. The strength/weakness of this restoration will be mentioned, also. If it has been used appropriately in carefully selected case, it can satisfy not only dentist's demand of sparing dental hard tissue but also patient's desire of seeking a esthetic restorations with a natural appearance.

• 대한치과교정학회지
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• 제36권3호
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• pp.188-197
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• 2006

교정 치료 시 사용되는 섬유 강화 컴포지트(FRC, fiber reinforced composite)는 구강 내에서 저작압 등의 지속적인 응력과 수분 흡수 등의 이유로 파절이 일어나는 경우가 있다. 이 때 모든 FRC를 제거하지 않고 수리(repair)하는 경우에 적절한 강도를 얻기 위해 첨가해야 할 FRC의 양 및 그 파절 양상을 알아보고자 하였다. 두 개의 FRC strips를 1, 2, 3, 그리고 4mm 만큼 겹쳐(E1, E2, E3, E4군) 시편을 만드는 방법으로 수리를 재현한 후 light emitting diode 광중합기로 중합하고, 3점 굽힘 실험을 시행하여 겹침 길이와 접합 강도간의 관계에 대해 조사하였다. 최대 하중치는 E4군에서 2.67N으로 최대였고, 대조군(2.39N), E3군(2.35N), E2군(2.10N), 그리고 E1군(1.75N)의 순이었다. 강성 역시 최대 하중치와 같이 E4군(2.32 N/mm)에서 최대치를 기록하였으나, E3군(2.06N/mm)의 강성이 대조군(1.88N/mm)보다 더 큰 값을 보였다. 겹침 길이가 길수록 완전히 두 조각으로 파절되기 보다 가운데 또는 critical section 에서 굽힘 양상을 보였다. 반면 겹침 길이가 짧은 경우 두 조각으로 부러지는 파절 양상을 보였다. 이상의 실험에서 길이 10 mm인 연결자 형태의 FRC의 수리 시 적절한 강도를 얻기 위해서는 최소 3 mm의 strips를 겹쳐야 하고, 이 때 주로 나타나는 실패 양상인 굽힘을 최소화하기 위해 연결 부위에 바로 인접하여 두께가 급격하게 변하는 critical section의 보강이 필요할 것으로 사료된다.

• Restorative Dentistry and Endodontics
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• 제40권3호
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• pp.229-235
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• 2015

Objectives: To determine and compare the fracture resistance of endodontically treated maxillary central incisors restored with different posts and cores. Materials and Methods: Forty-eight upper central incisors were randomly divided into four groups: cast post and core (group 1), fiber-reinforced composite (FRC) post and composite core (group 2), composite post and core (group 3), and controls (group 4). Mesio-distal and bucco-lingual dimensions at 7 and 14 mm from the apex were compared to ensure standardization among the groups. Twelve teeth were prepared for crown restoration (group 4). Teeth in other groups were endodontically treated, decoronated at 14 mm from the apex, and prepared for posts and cores. Resin-based materials were used for cementation in groups 1 and 2. In group 3, composite was used directly to fill the post space and for core build-up. All samples were restored by standard metal crowns using glass ionomer cement, mounted at $135^{\circ}$ vertical angle, subjected to thermo-mechanical aging, and then fractured using a universal testing machine. Kruskal-Wallis and Mann-Whitney U tests were used to analyze the data. Results: Fracture resistance of the groups was as follows: Control (group 4) > cast post and core (group 1) > fiber post and composite core (group 2) > composite post and core (group 3). All samples in groups 2 and 3 fractured in restorable patterns, whereas most (58%) in group 1 were non-restorable. Conclusions: Within the limitations of this study, FRC posts showed acceptable fracture resistance with favorable fracture patterns for reconstruction of upper central incisors.

• 대한치과보철학회지
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• 제42권6호
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• pp.654-663
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• 2004

Statement of problem. According to the fracture pattern in several reports, fractures most frequently occur in the interface between the ceromer and the substructure. Purpose. The aim of this in vitro study was to compare the macro shear bond strength and microshear bond strength of a ceromer bonded to a fiber reinforced composite (FRC) as well as metal alloys. Material and methods. Ten of the following substructures, type II gold alloy, Co-Cr alloy, Ni-Cr alloy, and FRC (Vectris) substructures with a 12 mm in diameter, were imbedded in acrylic resin and ground with 400, and 1, 000-grit sandpaper. The metal primer and wetting agent were applied to the sandblasted bonding area of the metal specimens and the FRC specimens, respectively. The ceromer was placed onto a 6 mm diameter and 3 mm height mold in the macro-shear test and 1 mm diameter and 2 mm height mold in the micro-shear test, and then polymerized. The macro- and micro-shear bond strength were measured using a universal testing machine and a micro-shear tester, respectively. The macro- and micro-shear strength were analyzed with ANOVA and a post-hoc Scheffe adjustment ($\alpha$ = .05). The fracture surfaces of the crowns were then examined by scanning electron microscopy to determine the mode of failure. Chi-square test was used to identify the differences in the failure mode. Results. The macro-shear strength and the micro-shear strength differed significantly with the types of substructure (P<.001). Although the ceromer/FRC group showed the highest macroand micro-shear strength, the micro-shear strength was not significantly different from that of the base metal alloy groups. The base metal alloy substructure groups showed the lowest mean macro-shear strength. However, the gold alloy substructure group exhibited the least micro-shear strength. The micro-shear strength was higher than the macro-shear strength excluding the gold alloy substructure group. Adhesive failure was most frequent type of fracture in the ceromer specimens bonded to the gold alloys. Cohesive failure at the ceromer layer was more common in the base metals and FRC substructures. Conclusion. The Vectris substructure had higher shear strength than the other substructures. Although the shear strength of the ceromer bonded to the base metals was lower than that of the gold alloy, the micro-shear strength of the base metals were superior to that of the gold alloy.

• 대한치과보철학회지
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• 제44권5호
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• pp.526-536
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• 2006

Statement of problem : Use of fiber composite technology as well as development of nonmetal implant prosthesis solved many problems due to metal alloy substructure such as corrosion. toxicity, difficult casting, expensiveness and esthetic limit. After clinical and laboratory test, we could find out that fiber-reinforced composite prostheses have good mechanical properties and FRC can make metal-free implant prostheses successful. Purpose : The purpose of this study is to evaluate the flexural strength of implant fixed prosthesis using fiber reinforced composite. Material and methods : 2-implant fixture were placed in second premolar and second molar area in edentulous mandibular model, and their abutments were placed, and bridge prostheses using gold, PFG, Tescera, and Targis Vectris were fabricated. Tescera was made in 5 different designs with different supplements. Group I was composed by 3 bars with diameter 1.0mm and 5 meshes, 2 bars and 5 meshes for Group II, 1 bar and 5 meshes for Group III, and only 5 meshes were used for Group IV. And Group V is composed by only 3 bars. Resin (Tescera) facing was made to buccal part of pontic of gold bridge. All of gold and PFG bridges were made on one model, 5 Targis Vectris bridges were also made on one model, and 25 Tescera bridges were. made on 3 models. Each bridge was attached to the test model by temporary cement and shallow depression was formed near central fossa of the bridge pontic to let 5 mm metal ball not move. Flexual strength was marked in graph by INSTRON. Results : The results of the study are as follows. The initial crack strength was the highest on PFG. and in order of gold bridge Tescera I, Tescera II, Targis vectris, Tescera IV, Tescera III, and Tescera V. The maximum strength was the highest on gold bridge, and in order of PFG, Tescera I, Tescera IV Tescera II, Targis vectris, Tescera III, and Tescera V. Conculsions : The following conclusions were drawn from the results of this study. 1. Flextural strength of implant prosthesis using fiber reinforced composite was higher than average posterior occlusal force. 2. In initial crack strength, Tescera I was stronger than Tescera V, and weaker than PFG. 3. Kinds and number of auxillary components had an effect on maximum strength, and maximum strength was increased as number of auxillary components increased. 4 Maximum strength of Tescera I was higher than Targis vectris, and lower than PFG.

• 대한치과보철학회지
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• 제38권5호
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• pp.618-630
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• 2000

As Fiber-reinforced composite restorations cannot be made without leaving a marginal gap, luting cements play a pivotal role in sealing the margins as a prevention against margnal leakage. A recently introduced adhesive resin cement system is claimed to adhere chemically, as well as mechanically, to tooth substances, dental alloys and porcelain. But when considering the clinical variation conventional cementation using Zinc Phosphate and Glass-Ionomer can be requested. A vitro study was undertaken to compare microleakage and marginal fitness of Fiber-reinforced composite crowns(Targis/Vectris) depending upon luting cements. Fifty non-carious human premolar teeth were randomly divided into five experimental groups of 10 teeth each and luted with five luting cements. ($Bistite\;II^(R),\;Super-bond^(R),\;Variolink\;II^(R)$), Zinc phosphate and Glass-Ionomer cement) After 24 hours of being luted, all specimens were thermocycled 300 times through water bath of $5^{\circ}C\;and\;55^{\circ}C$ in each bath, then the quality of the marginal fitness was measured by the Digital Microscope and marginal leakage was characterized using Dye Penetration technique and the Digital Microscope The results were as follows : 1. The mean values of marginal fit were Bistite II($46.78{\mu}m$), Variolink II($56.25{\mu}m$), Super-Bond($56.78{\mu}m$), Glass-Ionomer($99.21{\mu}m$), Zinc Phosphate($109.49{\mu}m$) indicated a statistically significant difference at p<0.001. 2. The mean microleakage values of tooth-cement interface, restoration-cement interface were increased in the order of Variolink II, Bistite II, Super-Bond, Glass-Ionomer, Zinc Phosphate 3. Crowns luted with resin cement (Bistite II, Super-Bond, Variolink II, etc) exhibited less marginal gap and marginal leakage than those luted with conventional Glass-Ionomer and Zinc Phosphate cement. 4. The results indicated that all five luting systems yielded comparable and acceptable marginal fit.

• 구강회복응용과학지
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• 제39권4호
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• pp.187-194
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• 2023

목적: 포스트와 포스트 공간의 크기 불일치는 포스트 수복 중 흔히 발생하는 문제이며, 이러한 불일치는 섬유강화 복합레진 포스트의 결합강도에 영향을 미치기 때문에 이를 보상할 수 있는 적절한 접착 시멘트가 필요하다. 연구의 목적은 섬유강화 복합레진 포스트의 결합강도에 영향을 미치는 포스트 공간의 적합도와 접착 시멘트 종류에 따른 영향을 평가하는 것이다. 연구 재료 및 방법: 발거된 30개의 하악소구치를 근관 치료한 뒤, 준비된 포스트 공간에 따라 Fitting (F)과 Mismatching (M)의 두 그룹으로 분류했다. 이들 그룹은 접착 시멘트 종류에 따라 다시 RelyX Unicem (ReX), Luxacore dual (Lux) 및 Duolink (Duo)의 세 가지 하위 그룹으로 추가로 분류했다. 이후 시편을 만들어 만능 물성 시험기 상에서 결합 강도를 측정했고 각 시편의 파절 양상을 관찰하여 분류했다. 결과: 실험의 결과로 ReX 및 Duo 하위 그룹에서는 F 그룹의 평균 결합 강도가 더 높았다. 그러나 Lux 하위 그룹은 F 그룹과 M 그룹 간에 큰 차이가 없었다. 파절 양상 분석에서 ReX 하위 그룹은 시멘트와 상아질 사이의 접착 실패만 관찰되었다. 결론: 본 연구 결과, 섬유강화 복합레진 포스트의 결합강도는 접착 시멘트의 종류, 포스트 공간과 포스트 직경의 불일치에 의해 영향을 받는 것으로 나타났다. Rex는 다른 접착 시멘트와 비교 시 유의하게 높은 결합강도를 보였다. 포스트 직경은 모든 그룹에서 F그룹이 M그룹보다 높은 결합강도를 보였으며, 이 값은 ReX와 Duo 두 그룹에서 유의한 것으로 나타났다.

• 한국해양환경ㆍ에너지학회지
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• 제16권1호
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• pp.53-59
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• 2013

1990년대 이후, 중소형 폐 선박으로부터 생성되는 FRP를 재활용하기 위한 방법으로 층상으로 배열된 로빙층과 매트층을 분리하는 것은 친 환경적이면서도 경제적 재활용의 장점을 가지고 있다. 그러나 효율적으로 로빙층과 매트층을 분리하는 기술과 로빙층은 매트층에 비해 얇은 두께로 존재한다는 이유로 인해 로빙층을 매트층과 분리할 때 기계가 자동적으로 층간의 차이를 인식하는 방법은 아직 개발이 이루지지 않고 있다. 본 연구에서는 유리의 구성비가 다른 두 층의 화학적 성질의 차를 이용하여 광학적으로 층간 인식이 가능한 방법을 모색하였다. 또한 다양한 로빙층의 구성에도 자동적으로 절단위치를 분석하는 절단시스템과 최종생산물의 유용성을 확보할 수있는 다양한 크기의 유리섬유를 생산할 수있는 세단기를 개발하였다. 본 연구 결과로 광학적 인식기술과 유연한 절단기술 그리고 다양한 세단기술이 융합된 폐 FRP의 분리 공정의 단순화와 자동화를 달성하게 되었다.

• 구강회복응용과학지
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• 제32권3호
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• pp.149-157
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• 2016

성공적인 라미네이트 치료를 위해서는 치아형성 방법이 매우 중요하다. 법랑질에 국한된 보존적인 치아형성, 치태조절이 용이한 치은연선상(equigingival) 변연, 가능한 존재하는 접촉점의 유지 등의 조건이 일반적으로 알려져 있으나 구체적인 치아형성 디자인에 관하여는 논쟁의 여지가 존재한다. 생역학적으로 고려해볼 때, 다음과 같은 사항들이 추천된다. 절단면 피개는 심미적 요구와 전방유도의 재설정 필요 여부 측면에서 결정해야 하며, 법랑질 두께가 충분한 경우에는 구개측 연장을 하는 것이 좋으나 응력 집중이 큰 구개오목(palatal concavity)에 변연이 위치하는 것은 부적절하다. 인접면 연장은 증례에 따라 선택적으로 시행하며, 인접면에 레진수복물이 존재하는 경우에는 표면처리 후 레진 수복물을 절반 이상 피개하는 형태의 라미네이트로 수복한다. 변색이 심하지 않은 근관치료가 시행된 치아의 경우 라미네이트 수복을 고려해 볼 수 있으며, 이 때 섬유강화레진 포스트를 사용하는 것을 추천한다.