중합광원과 레진 색상이 복합레진의 중합깊이에 미치는 영향

나준석,정선와,황윤찬,김선호,윤창,오원만,황인남 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.6

Purpose of this research is estimating polymerization depth of different source of light. XL 3000 for halogen light, Apollo 95E for plasma arc light and Easy cure for LED light source were used in this study. Different shade (B1 & A3) resin composites (Esthet-X, Dentsply, U.S.A.) were used to measure depth of cure. 1, 2, and 3 mm thick samples were light cured for three seconds, six seconds or 10 seconds with Apollo 95E and they were light cured with XL-3000 and Easy cure for 10 seconds, 20 seconds, or 40 seconds. Vicker's hardness test carried out after store samples for 24 hours in distilled water. Results were as following. 1. Curing time increases from all source of lights. curing depth increased(p<0.05). 2. Depth (that except 1mm group and 2mm group which lighten to halogen source of light) deepens in all groups, Vicker's hardness decreased(p<0.05). 3. Vicker's hardness of A3 shade composite was lower in all depths more than B1 shade composites in group that do polymerization for 10 seconds and 20 seconds using halogen source of light(p<0.05), but group that do polymerization for 40 seconds did not show difference(p>0.05). 4. Groups that do polymerization using Plasma arc and LED source of light did not show Vicker's hardness difference according to color at surface and 1mm depth(p>0.05), but showed difference according to color at 2mm and 3mm depth(p<0.05). The results showed that Apollo 95E need more polymerization times than manufacturer's recommendation (3 seconds), and Easy cure need polymerization time of XL-3000 at least.

Comparative Evaluation of Depth of Cure of Three High Viscosity Bulk Fill Composites versus Conventional Composite: An In Vitro Study

Meenu G Singla,Nikhil Relhan,Ishpreet Virdi 대한예방치과학회 2018 International Journal of Clinical Preventive Denti Vol.14 No.2

Objective: The aim of this study was to evaluate the microhardness and depth of cure of three high viscosity bulk fill resin composites and to compare it with a conventional composite. Methods: To evaluate depth of cure, the composite specimen was prepared using metallic mold with a hole of 4 mm depth and 4 mm internal diameter which was bulk filled with each of the three bulk fill composites (SonicFill, Filtek Bulk Fill Posterior & Beautifil Bulk Restorative) and light cured for 20 seconds. The conventional composite (Tetric N Ceram) was filled in the increments of 2-mm. The top and bottom surface hardness was measured using a Vickers microhardness indenter. The depth of cure was then calculated by dividing the bottom & top mean hardness values. Results: Sonicfill showed maximum surface microhardness followed by Beautifil Bulk restorative, Tetric N Ceram and Filtek Bulk Fill. Maximum depth of cure was seen in SonicFill followed by Filtek Bulk Fill, Tetric N Ceram and Beautifil Bulk restorative and the difference was statistically significant. SonicFill and Filtek Bulk Fill were able to achieve the minimum depth of cure value ≥0.80 at 4-mm depth. Beautiful bulk restorative composite was not able to achieve the minimum bottom to top ratio of 0.80. Conclusion: Microhardness and depth of cure is a material specific property and factors such as composition; content and size of fillers; viscosity and translucency of the material play an important role in determining the properties of the bulk fill composite.

Bulk-base 복합 레진의 중합 깊이에 따른 미세경도 평가

노유미,신비솔,김종수,유승훈 대한소아치과학회 2017 大韓小兒齒科學會誌 Vol.44 No.3

Composite resin becomes an essential material in pediatric dentistry. However, incremental filling of composite resin to minimize the polymerization shrinkage takes time. To reduce the polymerization shrinkage, clinicians and researchers have focused on bulk-filling materials. Bulk-base composite resin is newly introduced as bulk-filling composite resin. The purpose of this study was to evaluate microhardness profile of bulk-base composite resin according to the depth of cure. A high flow bulk-base material and a low flow bulk-base material were used for experimental group, and a conventional composite resin was used for control group. Each group consist of 20 specimens, 3.5 × 3.5 × 5.0 mm mold was used to make specimen. Specimens were sectioned at the 2 mm and the 3 mm depth with milling machine. Microhardness profile was measured at the surface, 2 mm depth, 3 mm depth, and 4 mm depth. Microhardness of control group showed statistically significant difference (p < 0.05) according to the polymerization depth. In contrast, experimental group showed no statistically significant difference, except between 0 mm and 4 mm at HFB, 0 mm and 2 mm, 0 mm and 3 mm at MFB. At the surface and the 2 mm depth, the control group showed higher microhardness than the experimental groups (p < 0.05). However, at the 4 mm depth, the experimental groups showed significantly higher microhardness (p < 0.05). The results from this study, the bulk-base composite resin showed higher microhardness at the 4 mm and lower microhardness at the surface and the 2 mm depth. Therefore, if bulk-base resin overcomes the mechanical weakness, it could be considered using in pediatric dentistry. 복합 레진은 소아치과 영역에서 대중적으로 사용되는 재료가 되었다. 하지만 복합 레진은 중합 수축을 최소화하기 위하여 적층 충전을 해야 하기 때문에 긴 시술 시간이 필요하다. 이러한 문제를 극복하기 위하여 임상가들은 bulk-filling 재료에 관심을 돌리기 시작하였고, 최근 bulk-base 복합 레진이 새로 출시되었다. 본 연구는 bulk-base 복합 레진의 깊이별 미세경도 측정값을 비교, 평가하였다. 실험군으로 1종의 저점도 bulk-base 복합 레진과 1종의 고점도 bulk-base 복합 레진을 사용하였고 대조군으로 1종의 전통적 복합레진을 사용하였다. 각 깊이별 재료들의 미세경도에 대한 결과로 대조군의 경우는 중합 깊이가 깊어질수록 미세경도의 유의한 차이를 보였다(p < 0.05). 이에 반해 실험군 인 HFB는 0 mm와 4 mm에서, 그리고 MFB는 0 mm와 2 mm, 0 mm와 3 mm에서 각각 유의한 차이를 보였으나 높이에 따른 유의한 감소 경향을 보이지는 않았다. 각각의 깊이에서 시편들의 미세경도를 비교하였을 때 표면과 2 mm에서는 대조군이 실험군보다 큰 미세경도를 보였다(p < 0.05). 3 mm에서는 저점도 실험군이 대조군보다 미세경도가 크게 나왔으나 통계적으로 유의한 차이는 아니었다. 하지만 4 mm에서는 모든 실험군이 대조군보다 통계적으로 유의하게 큰 미세경도 값을 보였다(p < 0.05). 이번 실험을 통하여 bulk-base 복합 레진이 4 mm에서 기존의 복합 레진보다 더 높은 미세경도를 보였고 표면과 2 mm에서는 더 낮은 미세경도를 보이는 것을 관찰하였다. 그러므로 bulk-base 레진의 기계적 성질의 향상을 통해 표면의 낮은 미세경도 특성이 극복된다면 소아 환자의 수복 치료 시 적용이 고려되어 질 만 할 것이다.

광원의 종류에 따른 복합레진의 중합거동 및 중합률에 관한 연구

류주희,이인복,유현미,김미자,석창인,권혁춘 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.4

Objectives: The purpose of this study was to observe the reaction kinetics and the degree of polymerization of composite resins when cured by different light sources and to evaluate the effectiveness of the blue Light Emitting Diode Light Curing Units (LED LCUs) compared with conventional halogen LGUs. Materials and Methods: First, thermal analysis was performed by a differential scanning calorimeter(DSC). The LED LCU (Elipar Freelight, 320㎽/㎠) and the conventional halogen LCU (XL3000, 400㎽/㎠) were used in this study for curing three composite resins (SureFil, Z-250 and AEliteFLO). Second, the degree of conversion was obtained in the composite resins cured according to the above curing mode with a FTIR. Third, the measurements of depth of cure were carried out in accordance with ISO 4049 standards. Statistical analysis was performed by two-way ANOVA test at 95% levels of confidence and Duncan's procedure for multiple comparisons. Results: The heat of cure was not statistically different among the LCUs (p > 0.05). The composites cured by the LED (Exp) LCUs were statistically more slowly polymerized than by the halogen LCU and the LED (Std) LCU (p< 0.05). The composite resin groups cured by the LED (Exp) LGUs had significantly greater degree of conversion value than by the halogen LCU and the LED (Std) LCU (p = 0.0002). The composite resin groups cured by the LED (Std) LGUs showed significantly greater depth of cure value than by the halogen LCU and the LED (Exp) LGU (p < 0.05).

Effect of the Laser Beam Size on the Cure Properties of a Photopolymer in Stereolithography

Jae-Hyung Sim,Eun-Dok Lee,Hyeog-Jun Kweon 한국정밀공학회 2007 International Journal of Precision Engineering and Vol.8 No.4

Stereolithography (SLA) is a technique using a laser beam to cure a photopolymer liquid resin with three-dimensional computer-aided design (CAD) data. The accuracy of the prototype, the build time, and the cured properties of the resins are controlled by the SLA process parameters such as the size of the laser beam, scan velocity, hatch spacing, and layer thickness. In particular, the size of the laser beam is the most important parameter in SLA. This study investigated the curing properties of photopolymers as a function of the laser beam size. The cure width and depth were measured either on a single cure line or at a single cure layer for various hatch spacings and laser beam sizes. The cure depth ranged from 0.23 to 0.34 mm and was directly proportional to the beam radius, whereas the cure width ranged from 0.42 to 1.07 mm and was inversely proportional to the beam radius. The resulting surface roughness ranged from 1. 12 to 2.23 ㎛ for a ratio of hatch spacing to beam radius in the range 0.5-2.0 at a beam radius of 0.17 mm and a scan velocity of 125 mm/sec.

Effect of the Laser Beam Size on the Cure Properties of a Photopolymer in Stereolithography

Sim, Jae-Hyung,Lee, Eun-Dok,Kweon, Hyeog-Jun Korean Society for Precision Engineering 2007 International Journal of Precision Engineering and Vol.8 No.4

Stereolithography (SLA) is a technique using a laser beam to cure a photopolymer liquid resin with three-dimensional computer-aided design (CAD) data, The accuracy of the prototype, the build time, and the cured properties of the resins are controlled by the SLA process parameters such as the size of the laser beam, scan velocity, hatch spacing, and layer thickness, In particular, the size of the laser beam is the most important parameter in SLA, This study investigated the curing properties of photopolymers as a function of the laser beam size, The cure width and depth were measured either on a single cure line or at a single cure layer for various hatch spacings and laser beam sizes, The cure depth ranged from 0.23 to 0.34 mm and was directly proportional to the beam radius, whereas the cure width ranged from 0.42 to 1.07 mm and was inversely proportional to the beam radius, The resulting surface roughness ranged from 1.12 to $2.23{\mu}m$ for a ratio of hatch spacing to beam radius in the range 0.5-2.0 at a beam radius of 0.17 mm and a scan velocity of 125 mm/sec.

Hydroxyethyl methacrylate (HEMA)와 Triethylene glycol dimethacrylate (TEGDMA)가 실험적 복합레진의 특성에 미치는 영향

한만형,최부병,우이형,Han Man-Hyun,Choi Boo-Byung,Woo Yi-Hyung 대한치과보철학회 2003 대한치과보철학회지 Vol.41 No.4

Purpose : The purpose of this study was to compare HEMA and TEGDMA as diluents for the composite resin. Material and methods : Eight kinds of experimental light curable composite resins were prepared and used. Concentrations of monomer and filler were same for all experimental composites, except, the diluent's ratios to the monomer. The ratio of diluents to Bis-GMA were 15%, 20%, 25%, and 30%, and two kinds of diluents were used, so total experimental groups were eight including one control group of 25% TEGDMA. Results : Depth of cure, flexural strength, shear bond strength to bovine enamel, shear bond strength to bovine dentin, water absorption and solubility of composites in water were measured. Sample size for each groups were 10. Arithmetic means were used as each groups representative values, and regression test for two diluents and low concentrations, Duncan's multiple range test, and Two-way ANOVA test were done for kinds of diluents and its concentrations at level of 0.05. Conclusion : Following results were obtained ; 1. There were not significant differences in effects of HEMA and TEGDMA to depth of cure, flexural strength of composites and shear bond strength to bovine enamel (p>0.05). 2. Increase of the concentrations of the diluents made the depth of cure (p<0.001) and flexural strength (p<0.05) a little higher. 3. Shear bond strength to dentin was higher on HEMA containing composites than TEGDMA containing composites (p<0.001). 4. Water absorption was higher on HEMA containing composites than TEGDMA containing composites (p<0.01).

Degree of conversion of resin composite cured by light through a translucent fiber posts

Somchai Urapepon 대한치과보철학회 2014 The Journal of Advanced Prosthodontics Vol.6 No.3

PURPOSE This study evaluated the depth of cure of resin composite cured by light through a translucent fiber post. MATERIALS AND METHODS The opaque plastic tubes in various lengths of 2, 4, 6, 8, 10, 12, 14 mm. were filled with resin composite in which two different translucent fiber posts were inserted into the center and photo-polymerized for 40 seconds. The degree of conversion of the cured composite at bottom surface were examined using Fourier transform infrared attenuated total reflection spectrometer (FTIR/ATR) at 0.1, 0.5 and 1.0 mm apart from the post surface. RESULTS The degree of conversion of the 0.1 mm, 0.5 mm, 1.0 mm apart from the post surface was highest at the 2 mm level and continuously decreased when the distance from the light source was increased and drastically decreased when the depth from the top of the post was greater than 4-6 mm. For each level, the highest degree of conversion was at 0.1 mm from the post surface and decreased continuously when the distance apart from the post surface was increased. CONCLUSION The quantity of light transmission depends on the type of post and the light transmission capability of the post, especially after 4-6 mm depth and the area further apart from the post surface, are insufficient for clinical light activation of resin composite.

Degree of conversion of resin composite cured by light through a translucent fiber posts

Urapepon, Somchai The Korean Academy of Prosthodonitics 2014 The Journal of Advanced Prosthodontics Vol.6 No.3

PURPOSE. This study evaluated the depth of cure of resin composite cured by light through a translucent fiber post. MATERIALS AND METHODS. The opaque plastic tubes in various lengths of 2, 4, 6, 8, 10, 12, 14 mm. were filled with resin composite in which two different translucent fiber posts were inserted into the center and photo-polymerized for 40 seconds. The degree of conversion of the cured composite at bottom surface were examined using Fourier transform infrared attenuated total reflection spectrometer (FTIR/ATR) at 0.1, 0.5 and 1.0 mm apart from the post surface. RESULTS. The degree of conversion of the 0.1 mm, 0.5 mm, 1.0 mm apart from the post surface was highest at the 2 mm level and continuously decreased when the distance from the light source was increased and drastically decreased when the depth from the top of the post was greater than 4-6 mm. For each level, the highest degree of conversion was at 0.1 mm from the post surface and decreased continuously when the distance apart from the post surface was increased. CONCLUSION. The quantity of light transmission depends on the type of post and the light transmission capability of the post, especially after 4-6 mm depth and the area further apart from the post surface, are insufficient for clinical light activation of resin composite.

Influence of curing condition and carbonation on electrical resistivity of concrete

윤인석,홍성원,강현구 사단법인 한국계산역학회 2015 Computers and Concrete, An International Journal Vol.15 No.6

The electrical resistivity of air-dried, saturated, and carbonated concretes with different mixture proportions was monitored to evaluate and quantify the influence of the age of the specimen, carbonation, and curing condition. After 28 days of curing, four prepared specimens were stored in a vacuum chamber with 5% CO2 for 330 days to make carbonated specimens. Four of the specimens were placed in water, and four specimens were cured in air until the end of the experiments. It was observed that the electrical resistivity of the carbonated specimens increased as carbonation progressed due to the decrease of porosity and the increase of hydrated products. Therefore, in order to estimate the durability of concrete, its carbonation depth was used as the measurement of electrical resistivity. Moreover, an increase of electrical resistivity for air-dried and saturated concretes was observed as a function of age of the specimen. From the relationship between chloride diffusivity provided by Yoon et al. (2007) and the measurements of electrical resistivity, it is expected that the results well be of significant use in calibrating chloride diffusivity based on regular measurements of electrical resistivity during concrete construction.