• 대한치과의사협회지
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• 제24권7호통권206호
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• pp.633-642
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• 1986

In order to evaluate the effects of various finishing devices (Sof-Lex disc, diamond point, rubber point, fussure bur) on the surface roughness or two composite resins (Restodent, Enamelite 500), 15 specimens for each composite resin were made in the mold. Composite resin was prepared on the mixing pad by manufacturer's direction and filled in the mold cavity. A sheet of matrix is immediately placed on it and hold for 5 minutes to polymerize the resin. Surface finish was done after 10 minutes from the start of mixing. Scanning electron microscopy and surface profilometer were used to evaluate the surface roughness, porositites and striations of dental composite resins. The following results were observed; 1. The best finished surface was formed by celluloid matrix band. 2. Rubber point was excellent polishing device for Restodent. 3. Sof-Lex disc was the device of choice for polishing Enamelite 500. 4. Different polishing methods were effective for different composite resins. 5. SEMs of variously finished surfaces supported the profilometer measurements.

• 치위생과학회지
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• 제21권4호
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• pp.251-259
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• 2021

Background: The purpose of this study was to investigate the effects of commercially available calamansi soju and other alcoholic beverages on the microhardness and erosion of resin restorations. Methods: In this study, we evaluated the effects of Calamansi soju, Chamisul fresh, Cass fresh, and Gancia Moscato D'asti on resin restorations. Jeju Samdasoo and Coca-Cola were used as negative and positive controls, respectively. Specimens to be immersed in the beverages were manufactured using composite resin according to the product instructions. In each group, the surface microhardness was measured using a surface microhardness instrument before and after immersion for 5, 15, 30, and 60 minutes. The pattern of change in the surface of the composite resin was observed under a scanning electron microscope (SEM). Paired t-tests, one-way ANOVA, and repeated measures ANOVA were performed to compare the surface microhardness of the specimens, and the Tukey test was used as a post hoc test. Results: The pH of all beverages except Jeju Samdasoo was <5.5, which is the critical pH that can induce erosion. The difference in surface microhardness of the composite resin before and after immersion for 60 minutes was significant in all groups. In particular, the largest change in surface microhardness was observed in the calamansi soju group. In the SEM analysis, loss of composite resin was observed in all groups except the Jeju Samdasoo group, and rough surfaces with pores of various sizes were observed. Conclusion: In this study, all beverages except Jeju Samdasoo decreased the microhardness of the composite resin surface, and it was confirmed that calamansi soju had the greatest change.

• 대한치과기공학회지
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• 제41권1호
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• pp.21-27
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• 2019

Purpose: To evaluate 2D and 3D of occulsal, mesial-occlusal and mesial-occlusal-distal cavity of composite resin inlay. Methods: Abutment tooth 16, 36 of FDI system was selected for the study. Inlay prostheses classified as occlusal cavity (OC group), mesial-occlusal (MOC) and mesial-occlusal-distal cavity (MODC) were prepared using composite resin. Composite resin was injected with composite resin in prepared tooth cavity and then photopolymerized with UV light. Additional thermal polymerization was performed. Marginal gap of composite resin inlays were measured by digital microscope(x160) with silicone replica technique. The data was analyzed from statistical software for Kruskal-Wallis test (${\alpha}=0.05$). 3-dimensional analysis was analyzed through superimposition method. Results: The smallest 2D marginal fit measure of the three groups was $47.0{\pm}21.6{\mu}m$ in the MOC group. The largest 2D marginal was $69.1{\pm}33.8{\mu}m$ in the MODC group. In the trueness of the three groups, the most accurate figure was $14.4{\pm}2.3{\mu}m$ for the MODC group. In Precision, the most accurate figure was $14.5{\pm}4.3{\mu}m$ for the MODC group. Conclusion : In this study, 2D marginal fit of OC, MOC, and MODC cavities fabricated with composite resin was applicable to all clinical applications. In the 3D inner surface accuracy evaluation, the MODC group showed the accuracy results.

• 대한치과의사협회지
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• 제13권5호
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• pp.449-452
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• 1975

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1990년도 추계학술대회
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• pp.64-67
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• 1990

Bending strength, bending elastic modulus ,and fracture toughness of different types of dental composite resins were deter mined. The relationship between bending strength, fracture toughness and filler volume fraction of dental composite resin was understood. In Acoustic Emission(AE) behavior during fracture toughness test, characteristic generation patterns of each type were understood. The fracture toughness values, AE generation patterns, and the nature of fracture surface were analyzed to understand fracture behavior of dental composite resin.

• 치위생과학회지
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• 제9권2호
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• pp.189-195
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• 2009

치과용 가시광선 종합형 복합수지의 광중합효율을 높이기 위해 합성한 bis-GMA 레진에 2종의 새로운 광중감제인 PD, DA를 넣고 현재 가장 많이 사용되고 있는 광중감제인 CQ와 조사시간 및 광중감제의 양을 증가시키며 광중합효율을 비교한 결과 다음과 간은 결론을 얻었다. 1. Bis-GMA의 합성여부를 적외선 흡수 분광법, 핵자기공명 흡수법 등 분광학적인 방법으로 확인하였으며 핵자기 공명 흡수법으로 확인한 결과 이성질체가 존재함을 알 수 있었다. 2. 조사시간이 증가됨에 따라 광중감제의 종류에 관계없이 광중합효율이 점차 증가되었으며, 약 60초까지 조사였을 때에는 광중합효율이 급격히 증가되었으나 그 이상 조사하여도 광중합효율이 크게 증가되지 않았다. 3. 같은 시간 조사하였을 경우 대체적으로 광중합효율이 증가되었으나 CQ와 DA의 경우는 3.0 mol% 첨가하였을 때에 비해 6.0 mol% 첨가되었을 때의 광중합효율이 오히려 더 낮게 나타나는 양상을 보였다. 4. 같은 시간동안 조사하고, 같은 양의 광중감제를 첨가하였을 경우 DA < CQ < PD 순으로 광중합효율이 높게 나타나서 CQ에 비해 PD를 첨가하였을 때의 광중합효율이 높게 나타났다. 5. 이상의 결과로부터 PD가 CQ를 대체할 수 있는 효율이 좋은 새로운 광중감제로서 사용될 가능성을 보여주었다.

• 대한치과의사협회지
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• 제10권12호
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• pp.785-794
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• 1972

• 대한치과의사협회지
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• 제26권8호통권231호
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• pp.693-699
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• 1988

Composite Resin(콤포짓트 레진) 수복은 3급,4급(견치의 원심면 제외) 및 5등급 전치부와동에 주로 사용되었으나 재료의 개선으로 인해 1급,2급 및 견치 3급와동의 원심면에도 제한적으로 사용이 가능하게 되었다. 물론 실제적인 와동의 설계는 수복요건에 따라 다양한 형태변화를 부여할 수도 있다.

• Restorative Dentistry and Endodontics
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• 제42권1호
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• pp.39-47
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• 2017

Objectives: Although the coating of surface sealants to dental composite resin may potentially reduce bacterial adhesion, there seems to be little information regarding this issue. This preliminary in vitro study investigated the adhesion of Streptococcus mutans (S. mutans) on the dental composite resins coated with three commercial surface sealants. Materials and Methods: Composite resin (Filtek Z250) discs (8 mm in diameter, 1 mm in thickness) were fabricated in a mold covered with a Mylar strip (control). In group PoGo, the surfaces were polished with PoGo. In groups PS, OG, and FP, the surfaces polished with PoGo were coated with the corresponding surface sealants (PermaSeal, PS; OptiGuard, OG; Fortify Plus, FP). The surfaces of the materials and S. mutans cells were characterized by various methods. S. mutans adhesion to the surfaces was quantitatively evaluated using flow cytometry (n = 9). Results: Group OG achieved the lowest water contact angle among all groups tested (p < 0.001). The cell surface of S. mutans tested showed hydrophobic characteristics. Group PoGo exhibited the greatest bacterial adhesion among all groups tested (p < 0.001). The sealant-coated groups showed statistically similar (groups PS and FP, p > 0.05) or significantly lower (group OG, p < 0.001) bacterial adhesion when compared with the control group. Conclusions: The application of the surface sealants significantly reduced S. mutans adhesion to the composite resin polished with the PoGo.

• 대한치과기공학회지
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• 제33권4호
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• pp.291-297
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• 2011

Purpose: The purpose of this study was to know the availability of three photosensitizers, CQ, PD, DA, as a photosensitizer of dental resin composite. We want to know abortion band around visible light region for the using potential possibility as a photosensitizer for visible light cured dental composite resin. And I studied to know the relative photodecomposition ratio of three photosensitizers with or without photoinitiator, DAEM. Methods: The photodecomposition of three photosensitizers were studied by UV absorption spectroscopy in ethanol and determined by same instrument with irradiation time for relative photodecomposition. In order to study the effect of amine on photodecomposition was added the DAEM in the photosensitizer solution and the relative rate was measured by the same procedure with aove mentioned. Results: The all of three photosensitizers are absorbed around visible light region. The relative rate of decrease in absorbance incereased in the order: CQ < BD < PD. The effect of DAEM on the photodecomposition of the photosensitizers was appeared different results without DAEM. The photodecomposition rate of PD and DA decreased somewhat with the addition of amine, while that of CQ increased. The rtealtive photodecomposition rate increased in the oprder: BD ${\leq}$ CQ < PD with the addition of amine, but the differnce was not significant. Conclusion: PD and DA like CQ gives to the possibility of use as a photosensitizer for visible light cured dental composite resin by absorption around visible light region and photodecomposition in the maximum absorption wavelength. And it is showed that PD and DA are not effective decomposed with amine initiator, DAEM but CQ decomposed with DAEM effectively. This result may be due to a different mechanism operating for the decomposition of photosensitizers in the presence of amine.