• 한국산학기술학회논문지
• /
• 제3권2호
• /
• pp.101-109
• /
• 2002

법랑 재료인 프리트, 점토 및 안료의 배합비를 달리하여 법랑 시편을 제작하고, 시료들의 색상을 측색계(JS555)를 이용하여 분석하였다. 법랑의 색상 분석은 안료 외에도 프리트의 성질에 크게 좌우되며, 소성 전후의 법랑의 색깔이 확연히 변하므로 생산 표준화를 위하여 필요한 작업이다.

• 대한치과기공학회지
• /
• 제31권1호
• /
• pp.23-36
• /
• 2009

The goal of esthetic restoration is to achieve morphologic, optical, and biologic acceptance. Creation of a natural looking ceramic restoration, which blends harmoniously with surrounding dentition, is not always achieved. A successful color match is an important aspect of any esthetic dental restoration. Since natural enamel has inherent translucency, it is important that ceramic restorations reproduce the translucency and color of the natural teeth. However, the final color match of porcelain crowns to adjacent natural dentition remains some problem. Difficulties related to color matching arise from the structural differences that exist between metal ceramic crowns and natural teeth, the limited range of available ceramic shades, inadequate shade guides, different types of metal alloys, repeated firing, the condensation technique, and varying compositions of ceramic materials. Many factors contribute to the esthetic success of dental restoration: optical properties such as color and its elements of hue, value, and chroma; translucency and opacity; light transmission and scattering; and metamerism and fluorescence. The purpose of this study was to determine the color changes of metal-ceramic system with different veneering porcelain powder after repeated firing. The objectives of this in vitro study were to measure the lightness($L^*$), chromaticity($a^*$), chromaticity($b^*$), chroma($C^*$), hue(h), reflectance(%), color difference(${\Delta}E$). The following conclusions were obtained: 1. An increase in the number of firings resulted in decrease in lightness($L^*$) but increase in chromacticity($a^*$) with all porcelain. After the second sintering resulted in decrease in chromacticity($b^*$) with opaque-dentin porcelain and dentin porcelain but in increase with enamel porcelain and translucency porcelain. And after the second sintering resulted in decrease in chroma($C^*$) with opaque-dentin porcelain and dentin porcelain, but on the whole side in decrease with enamel porcelain and translucency porcelain. 2. After the second firing, a increase in the number of firings resulted in decrease reflectance(%) in all wavelength. 3. There were noticeable color differences(${\Delta}E$) between first sintering and multiple firings(dentin porcelain: 5.29~8.15, opaque-dentin porcelain: 4.83~8.2, enamel porcelain: 8.93~13.15, translucency porcelain: 9.37~12.91), but the color difference(${\Delta}E$) after second sintering were down to 4.87 in all porcelain. 4. Given the NBS Criteria, a 'trace' was not found this study but a 'slight' was found 2-3, 3-5 in dentin porcelain, 2-3 in opaque-dentin porcelain, 3-5, 5-10 in enamel porcelain and translucency porcelain, a 'noticeable' was 2-5, 3-10, 5-10 in dentin porcelain and opaque-dentin porcelain, 2-3, 2-5, 3-10 in enamel porcelain 2-3, 3-10 in translucency porcelain, an 'appreciable' was 1-2, 1-3, 2-10 in dentin porcelain 1-2, 1-3, 2-10, 3-10 in opaque-dentin porcelain, 2-10 in enamel porcelain, 2-5, 2-10 in translucency porcelain, a 'much' was 1-5, 1-10 in dentin porcelain and opaque-dentin porcelain, 1-2, 1-3, 1-5 in enamel porcelain 1-2, 1-3, 1-5, 1-10 in translucency porcelain, a 'very much' was 1-10 in enamel porcelain.

• 한국산학기술학회:학술대회논문집
• /
• 한국산학기술학회 2002년도 춘계학술발표논문집
• /
• pp.197-199
• /
• 2002

Samples of enamel wear for kitchen works were made at the Kordco Enamel Co. We analyzed the colors of enamel wears with Color Meter (JS555). The colors of enamel wears could be controled by mixing ratio of frits and pigments. Many kinds of frits and pigments were tested, and colors of enamel wears could be changed by variable frits. Colors were weakly changed by several mixing ratio of pigments.

• 한국치위생학회지
• /
• 제10권3호
• /
• pp.473-481
• /
• 2010

Objectives : To evaluate the effect of fluoride application on the color and microhardness of bleached enamel and compare it to that of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) application. Methods : Twenty freshly extracted human adult molar were each sectioned into halves, the specimens divided and treated according to five experimental groups: Group 1, treatment with 10% carbamide peroxide (CP) bleaching agent; Group 2, treatment with 10% CP followed by a 1.23% fluoride gel application; Group 3, treatment with 10% CP followed by a 2.23% sodium fluoride varnish application; Group 4, treatment with 10% CP followed by a 0.11% sodium fluoride gel application; Group 5, treatment with 10% CP followed by a CPP-ACP gel application. All groups were treated 6 h per day for 14 days then immersed in distilled water for 2 weeks. Changes in enamel color were evaluated on Baseline and Day 14. Microhardness were evaluated on Baseline, Days 7 and 14. Statistical analysis was performed using one-way ANOVA and post-hoc Tukey tests. Results : All the bleached enamel specimens revealed increased whiteness and overall color value. Group 1 showed the lowest microhardness values than that of Groups 2, 3, 4 and 5. In all groups, the hardness of tooth after bleaching showed a significant decrease in the microhardness as compared with the one prior to tooth bleaching. The specimens treated with remineralizing agents showed relatively less reduction in enamel microhardness than control group. Conclusions : The addition of fluoride and CPP-ACP did not impede the whitening effect. The use of remineralizing agents during bleaching treatment can significantly enhance the microhardness of bleached enamel.

• 대한치과교정학회지
• /
• 제48권4호
• /
• pp.245-252
• /
• 2018

Objective: We aimed to perform in-vitro evaluation to compare 1) shear bond strength (SBS), adhesive remnant index (ARI), and color change between self-etched and acid-etched primers; 2) the SBS, ARI and color change between direct and indirect bonding; and 3) the enamel roughness (ER) between 12-blade bur and aluminum oxide polisher debonding methods. Methods: Seventy bovine incisors were distributed in seven groups: control (no bonding), direct (DTBX), and 5 indirect bonding (ITBX, IZ350, ISONDHI, ISEP, and ITBXp). Transbond XT Primer was used in the DTBX, ITBX, and ITBXp groups, flow resin Z350 in the IZ350 group, Sondhi in the ISONDHI group, and SEP primer in the ISEP group. SBS, ARI, and ER were evaluated. The adhesive remnant was removed using a low-speed tungsten bur in all groups except the ITBXp, in which an aluminum oxide polisher was used. After coffee staining, color evaluations were performed using a spectrophotometer immediately after staining and prior to bonding. Results: ISONDHI and ISEP showed significantly lower SBS (p < 0.01). DTBX had a greater number of teeth with all the adhesive on the enamel (70%), compared with the indirect bonding groups (0-30%). The ER in the ITBX and ITBXp groups was found to be greater because of both clean-up techniques used. Conclusions: Direct and indirect bonding have similar results and all the primers used show satisfactory adhesion strength. Use of burs and polishers increases the ER, but polishers ensure greater integrity of the initial roughness. Resin tags do not change the color of the teeth.

• 치위생과학회지
• /
• 제10권4호
• /
• pp.295-300
• /
• 2010

본 연구에서는 자가 미백제로 많이 사용되고 있는 10% CP를 이용하여, 불소가 함유되지 않은 미백제, 불소가 함유된 미백제, 그리고 10% CP로 미백한 후에 불소를 적용하여 하루에 8시간씩 14일 동안 처리함으로써, 치아표면의 색과 미세경도에 미치는 영향을 평가하여 다음과 같은 결론을 얻었다. 1. 색조 변화측정 결과, 대조군을 제외하고 미백 처리한 모든 군에서 치아 미백 후 시간 경과에 따라 $L^*$ 값과 ${\Delta}E^*$ 값에 유의한 차이가 있었고(p<0.05), 비슷한 수준의 미백효과와 함께 치아의 색조에서 노란색이 감소됨을 관찰할 수 있었다. 2. 미백 처리 전후의 법랑질의 표면경도를 분석한 결과 대조군에서는 별 차이를 보이지 않았으나, 미백 처리한 모든 군에서 유의한 미세경도 감소를 보였다(p<0.05). 특히 10% CP군은 가장 낮은 미세경도 수치를 보였고, 미백제에 불소가 함유된 군과 미백 후 불소를 적용한 군은 미세경도 감소폭이 줄어들었다. 이상의 결과를 종합해 보면, 2주간 진행되는 10% CP는 치아미백에 효과적이며, 미백제에 불소를 함유시켜도 미백에는 영향을 주지 않았으며, 표면미세경도는 불소가 함유되지 않은 미백제에 비해 덜 감소했다. 임상에서 미백으로 인한 부작용을 최소화하는데 적정 농도의 불소를 이용해 적용될 수 있도록 더 많은 연구가 이루어져야 할 것으로 사료된다.

• Restorative Dentistry and Endodontics
• /
• 제44권1호
• /
• pp.6.1-6.11
• /
• 2019

Objectives: The aim of the present study was to evaluate the effect of whitening mouth rinses alone and in combination with conventional whitening treatments on color, microhardness, and surface roughness changes in enamel specimens. Materials and Methods: A total of 108 enamel specimens were collected from human third molars and divided into 9 groups (n = 12): 38% hydrogen peroxide (HP), 10% carbamide peroxide (CP), 38% HP + Listerine Whitening (LW), 10% CP + LW, 38% HP + Colgate Plax Whitening (CPW), 10% CP + CPW, LW, CPW, and the control group (CG). The initial color of the specimens was measured, followed by microhardness and roughness tests. Next, the samples were bleached, and their color, microhardness, and roughness were assessed. Data were analyzed through 2-way analysis of variance (ANOVA; microhardness and roughness) and 1-way ANOVA (color change), followed by the Tukey post hoc test. The Dunnett test was used to compare the roughness and microhardness data of the CG to those of the treated groups. Results: Statistically significant color change was observed in all groups compared to the CG. All groups, except the LW group, showed statistically significant decreases in microhardness. Roughness showed a statistically significant increase after the treatments, except for the 38% HP group. Conclusions: Whitening mouth rinses led to a whitening effect when they were used after conventional treatments; however, this process caused major changes on the surface of the enamel specimens.

• Restorative Dentistry and Endodontics
• /
• 제37권2호
• /
• pp.90-95
• /
• 2012

Objectives: The purpose of this study was to determine the effect of resin infiltration technique on color and surface hardness of white spot lesion (WSL) with various degrees of demineralization. Materials and Methods: Ten human upper premolars were cut and divided into quarters with a $3{\times}4mm$ window on the enamel surface. Each specimens were separated into four groups (n = 10) and immersed in demineralization solution to create WSL: control, no treatment (baseline); 12 h, 12 hr demineralization; 24 h, 24 hr demineralization; 48 h, 48 hr demineralization. Resin infiltration was performed to the specimens using Icon (DMG). $CIEL^*a^*b^*$ color parameters of the enamel-dentin complex were determined using a spectroradiometer at baseline, after caries formation and after resin infiltration. Surface hardness was measured by Vickers Micro Hardness Tester (Shimadzu, HMV-2). The differences in color and hardness among the groups were analyzed with ANOVA followed by Tukey test. Results: Resin infiltration induced color changes and increased the hardness of demineralized enamel. After resin infiltration, there was no difference in color change (${\Delta}E^*$) or microhardness among the groups (p < 0.05). Conclusion: There was no difference in the effect of resin infiltration on color and hardness among groups with different extents of demineralization.

• 보존과학회지
• /
• 제35권1호
• /
• pp.33-40
• /
• 2019

During the conservation and maintenance of the birthplace center yard of President Asan Yoon Bosun, four porcelain enamel dishware were excavated from the central yard well. The glaze layer of excavated enamel was severely damaged; hence, the conservation process was done rapidly. In addition, scientific investigation and analysis were conducted to confirm the material properties of the glaze layer. It was confirmed that the outer surface was inverted and dried, while the inner surface was upright and fired during the glazing and drying process by measuring the film thickness. By examining the breakup phenomenon, the breaking up of the white enamel on the colored enamel was confirmed. This indicates that the colored glaze rose to the surface depending on the density of the colored glaze and white glaze. The investigation of the cross-section of the film confirmed that the lower layer formed according to the bonding properties with metal during the glazing process. Analysis of the constituents of the identified lower layer confirmed that there are differences between the specific components of the metal oxide of the lower layer and the surface color development of the upper layer.

• 치위생과학회지
• /
• 제9권5호
• /
• pp.525-530
• /
• 2009

이 연구는 35% 과산화요소를 이용한 전문가 치아미백술에 플라즈마 아크를 함께 적용하여 플라즈마 아크가 법랑질의 색조변화에 미치는 효과와 비커스경도와 주사전자현미경을 이용하여 법랑질 표면에 미치는 영향을 알아보고자 in vitro 평가를 시행하여 다음과 같은 결론을 얻었다. 1. 미백 횟수의 증가에 따라 색조변화량(${\Delta}E^*$)이 통계적으로 유의한 증가를 나타내었으며, 미백 제만 단독으로 적용한 대조군 보다 플라즈마 아프를 함께 적용하여 미백처리를 한 실험군의 색조변화량(${\Delta}E^*$)이 더 높게 나타나는 것을 알 수 있었다. 2. 미백처리 전 후 법랑질의 미세경도 측정 값을 분석한 결과 미백 처치를 함으로써 미세경도 값이 통계적으로 유의하게 감소되었고, 미백제에 플라즈마 아크를 함께 적용한 실험군에서 더 큰 미세경도의 감소가 나타나는 것을 알 수 있었다. 3. 주사전자현미경 관찰에서 미백 처치를 한 시료에서 법랑질 표면이 상당히 거칠어진 양상을 나타내는 것을 볼 수 있었다. 이상의 결과를 종합해 볼 때 전문가 치아미백술에서 플라즈마 아크를 함께 적용함으로써 색조변화를 더욱 상승시킬 수 있으나, 법랑질 표면의 미세경도와 형태변화를 증가시킬 수 있으므로 미백 효과는 증가시키면서 법랑질의 형태와 구조는 변화시키지 않는 안전한 미백 방법에 관한 연구가 이루어 져야 할 것으로 사료된다.