Color Stability of Acrylic Resin Teeth After Immersion in Staining Solutions / Análisis del Cambio de Color de Dientes Artificiales Tras Inmersión en Soluciones Colorantes

ABSTRACT: The objective of this study was to evaluate the color alteration of four brands of artificial teeth (Art Plus, Trilux, Bionote and Biolux), after immersion in color solutions of coffee, red wine and urucum. We used 80 artificial teeth, which were standardized with 2 mm thickness. Then, they were subjected to finishing and polishing, and divided into 4 groups (n = 05), which were immersed in one of the 3 types of dye, plus distilled water (control). The samples were immersed daily for 4 hours, then they were removed, washed in tap water, dried with absorbent paper and immersed in distilled water for the subsequent hours in a biological glasshouse at 37 ºC, for 21 days. The evaluation of the color change was made in the periods of 0, 7, 14 and 21 days, by means of the tristimulus colorimeter. The data were subjected to the ANOVA and Tukey test with a 5 % significance. The results showed that the urucum was the substance that caused the greatest staining while the coffee and the wine did not show statistical difference. Regarding trademarks, Trilux presented a statistical difference compared to the other commercial brands, revealing colorimetric alteration only in the 14-day period. It was concluded that the composition of the artificial teeth, the type of pigmenting agent and the immersion time determine the color change.

RESUMEN: El objetivo de este estudio fue evaluar la alteración de color de cuatro marcas de dientes artificiales (Art Plus, Trilux, Bionote y Biolux), después de inmersión en soluciones colorantes de café, vino tinto y urucum. Se utilizaron 80 dientes artificiales, los cuales fueron estandarizados con 2 mm de espesor. En seguida, los mismos fueron sometidos al acabado y pulido, y divididos en 4 grupos (n = 5), los cuales fueron inmersos en uno de los 3 tipos de colorante, más agua destilada (control). Las muestras permanecieron inmersas diariamente durante 4 horas, luego fueron retiradas, lavadas en agua corriente, secas con papel absorbente e inmersas en agua destilada por las horas subsiguientes en invernadero biológico a 37 ºC, por 21 días. La evaluación del cambio de color se realizó en los períodos de 0, 7, 14 y 21 días, por medio del colorímetro tristimulo. Los datos fueron sometidos a la prueba ANOVA y Tukey con un 5 % de significancia. Los resultados demostraron que el urucum fue la sustancia que provocó mayor manchado mientras que el café y el vino no presentaron diferencia estadística. En cuanto a las marcas comerciales, el Trilux presentó una diferencia estadística en comparación con las otras marcas comerciales, revelando alteración colorimétrica sólo en el período de 14 días. Se concluyó que la composición de los dientes artificiales, el tipo de agente pigmentante y el tiempo de inmersión determinan el cambio de color.

Analysis of factors related to oil-spilling and establishment of limit standards of Asparagi Radix / 中国中药杂志

Some samples of Asparagi Radix were collected from medical markets.Colors of Asparagi Radix were observed by human vision and recorded to judge whether samples were degenerative.Water content of Asparagi Radix was determined by a drying method.The chroma value and color difference were determined and calculated by a colorimeter.With the deepening of color,the L*value was decreased and a*and ΔE*values were increased.It showed that the results determined by colorimeter can replace the results of visual observation.An HPLC method was established and used to determine the contents of 5-hydroxymethylfurfural(5-HMF) in Asparagi Radix.The results showed the 5-HMF contents were from 0.002 255 to 0.049 14 mg·g-1 in some samples with yellowish-white or yellowish-brown color,significantly increased from 0.080 80 to 0.105 1 mg·g-1 in some samples with brown color,and up to 1.033 mg·g-1 in an oil-spilling sample with dark brown color.This result demonstrated that the 5-HMF contents were significantly increased by accompanied with the deepening of color.There were the significant negatively correlation between the 5-HMF content and the L*value(P<0.01) and positively correlation between the 5-HMF content and the a*or ΔE*value(P<0.01) by the spearman analysis.The oil-spilling and qualified samples were clustered into two alone categories by the cluster analysis.That the limited standards of the 5-HMF content is not higher than 0.02% by HPLC method and of the L*value is not less than 50 by colorimeter method were suggested for Asparagi Radix.It is firstly reported the multiple-factor analysis about oil-spilling and discoloration and the establishment of limited standard of Asparagi Radix.

Correlation Between Effective Components Content and Color Values of Indigo Naturalis Basde on Chromatometry / 中国实验方剂学杂志

Objective: To study the correlation between the color of Indigo Naturalis (powder and it's extracting solution) and effective components (indigo and indirubin) content. Method: The contents of indigo and indirubin in 27 batches of Indigo Naturalis were determined by HPLC,and the chromaticity values L*,a* and b* of powder and extracting solution were determined by color colorimeter. SPSS 20.0 software was used to analyze the correlation and multiple linear regression between the content of active components and the chromaticity values of Indigo Naturalis. Result: By visual observing the appearance of the powder,we find that,as the powder color deepened,the brightness values (L*) of the powder and extract were decreased,while the red-green value (a*) were increased. The correlation analysis showed that the contents of indigo were negatively correlated with the brightness value (L*) of the powder(Pa*)(PL*) of powder and extract (Pa*) (PConclusion: The darker the powder color of Indigo Naturalis,the higher the content of indigo and indirubin. The L* and a* values of indigo powder were more correlated with indigo and indirubin content than with the extracting solution. The color of powder was significantly correlated with the content of indigo and indirubin,which provided reference for rapid identification of Indigo Naturalis. The method of measuring the color of Indigo Naturalis by color colorimeter is stable,scientific and reliable.

A comparative evaluation of the staining capacity of microhybrid and nanohybrid resin-based composite to indian spices and food colorants: An In vitro study

Resin composite restorative materials can mimic the natural color and shade of the tooth. However, exogenous colorants from food and drinks can stain them due to adsorption. The influence of Indian food colorants and spices on resin composite restorations has not been evaluated extensively. Aim: This study aims to evaluate the staining capacity of microhybrid and nanohybrid resin-based composites, to saffron extract, tandoori powder, and turmeric powder. Subjects and Methods: Forty samples of microhybrid (Kulzer Charisma) and nanohybrid (3M Filtek Z350) resin composites were prepared using an acrylic template of dimension 5 mm × 3 mm. They were randomly divided into four groups and immersed into solutions of saffron extract, tandoori powder, and turmeric powder. Distilled water was used as the control group. Color values (L*, a*, b*) were measured by colorimeter using the CIE L*a*b* system before and after 72 h of immersion. Color differences ΔE*ab were statistically analyzed. Statistical Analysis Used: Two-way ANOVA and post-hoc Tukey (honest significant difference) test were done using IBM SPSS Statistics for Windows, Version 19.0. Armonk, NY: IBM Corp. Results and Discussion: All the immersion media changed the color of the resin composites to varying degrees. However, turmeric solution showed the maximum mean color variation ΔE*ab of 14.8 ± 2.57 in microhybrid resin composites and 16.8 ± 3.50 in nanohybrid resin composites. Conclusion: Microhybrid and nanohybrid resin composites tend to stain to Indian food colorants, especially to turmeric powder.

The effects of different denture cleaners on the discolored heat-cured denture base resin and artificial teeth / 实用口腔医学杂志

Objective:To evaluate the effects of different denture cleaners on the discoloration of heat-cured denture base resin and artificial teeth.Methods:40 same specifications of the heat-curing denture base resin and 40 artificial central incisors were immerced in an acombination stain of coffee,tea and soy sauce for 4 weeks.Then specimens and artificial teeth were randomly distributed into 4 groups and soaked in Polident,Steradent,0.5％ sodium hypochlorite solution and distilled water for 4 hours respectivelly(n =10).Color differences(△E) were measured by using a colorimeter and a denture spectrophotometer before and after staining,and after cleaning.Results:Before or after staining there was no difference of △E among the groups of denture base risn or artificial teeth(P ＞ 0.05).After cleaning the denture base resin and the artificial teeth in the group of 0.5％ sodium hypochlorite solution presented higher △E than the other groups(P ＜ 0.05),in group of distilled water presented lower △E than the other groups(P ＜ 0.05).No significant difference was found between Polident group and Steradent group(P ＞0.05).The △E of the denture base resin and artificial teeth.in distilled water group before staining and after cleaning were the highest among the groups(P ＜0.05).Conclusion:0.5％ sodium hypochlorite solution,Polident and Steradent are effective in removing the discoloration from the heat-cured acrylic resin and artificial teeth.0.5％ sodium hypochlorite solution is the most effective,Polident and Steradent are the similar.

Advance in quality assessment of Chinese materia medica using microscopic and morphological methods / 中国天然药物

Quality evaluation plays a vital role in ensuring safety and effectiveness of Chinese materia medica (CMM). Microscopic and morphological technologies can be used to distinguish CMM's characteristics, such as shape, size, texture, section, and smell, for authenticity and quality control of CMM. The microscopic and morphological applications of novel micro-technology, colorimeter, and texture analyzer for CMM identification are summarized and the future prospect is discussed in this paper. Various styles and complex sources of CMM are systemically reviewed, including cormophyte medicinal materials, fruit and seeds, pollen grain, and spore materials.

Correlation Analysis on Cross Section Color of Licorice and Its Active Ingredients / 世界科学技术-中医药现代化

This study was aimed to establish an objective and convenient method to evaluate the quality of licorice through the study on correlation between the cross section color and contents of active ingredients of licorice.Therefore,colorimeter was introduced and applied to determinate cross section color of licorice.Meanwhile,contents of five active ingredients of licorice were also determined.HPLC was used to determine liquiritin and glycyrrhizic acid.Colorimetric method was used to determine total saponins.Ultraviolet spectrophotometry was used to determine total flavonoids.Sulphuric acid-phenol colorimetry was used to determine polysaccharides.Correlation between the cross section color and content determination result was analyzed.The results showed that the correlation coefficient of glycyrrhizic acid content and L* was-0.578,P ＜ 0.001,the correlation coefficient with b* was 0.596,P ＜ 0.001;the correlation coefficient of liquiritin content and L* was-0.503,P =0.002,the correlation coefficient with b* was 0.890,P ＜ 0.001;the correlation coefficient of total flavonoids content and L* was-0.729,P ＜ 0.001,the correlation coefficient with b* was 0.724,P ＜ 0.001;the correlation coefficient of polysaccharides content and L* was 0.230,P =0.190,the correlation coefficient with b* was-0.390,P =0.023;the correlation coefficient of total saponins content and L* was-0.411,P =0.016,the correlation coefficient with b* was 0.738,P ＜ 0.001.It was concluded that the cross section color index of licorice has significant correlation with contents of glycyrrhizic acid,liquiritin,total flavonoids and total saponins.There was no significant correlation with content of polysaccharides.It illustrated the close correlation between cross section color of licorice and its active ingredients.Through the digitalized determination on color,contents of chemical composition in licorice can be initially determined or predicted objectively.It provided a new idea and method for the quality evaluation of Chinese herbal medicine.

Rancidness of Armeniacae Semen Amarum involving Bianzhuang Lunzhi / 中国中药杂志

This article aims to compare the qualities of Armeniacae Semen Amarum before and after rancidness, in order to study the rancidness of Armeniacae Semen Amarum. In the experiment, content of fatty oil, acid value and peroxide value were determined before and after rancidness,respectively. Meanwhile, HPLC, GC-MS were utilized to analyze laetrile and fatty acid components. Besides, colorimeter and e-nose were introduced to quantify and compare "color and odor". A correlation analysis was conducted on the above results. The results showed that color of post-rancidness Armeniacae Semen Amarum changed from yellow to brown, with sour and lower content of laetrile. On the contrary, acid and peroxide values increased significantly, with changes in fatty acid component. There was a considerable correlation between appearance characteristics and changes in internal quality. The "sensory analysis-quality identification system" can provide a certain scientific basis for prediction of the content of chemical components in traditional Chinese medicine, preliminary judgment of quality of traditional Chinese medicine and real-time quality monitoring, which offers us novel ideas and reference for storage principles of traditional Chinese medicines of "pre-event prediction, during-event intervention and post-event identification".

Color evaluation of low viscosity bulk-fill resin with composite resin capping layer

PURPOSE: The purpose of this study was to measure the color of low viscosity bulk-fill resin with a capping layer and to compare it with the color of microhybrid composite resin. MATERIALS AND METHODS: A low viscosity bulk-fill resin (SDR) and microhybrid composite resin of shade A2 (A2) or A3 (A3) were fabricated to 4 mm thickness and light cured for 20 seconds. CIE L*a*b* values of the resin specimens were measured with a colorimeter. Then shade A2 and A3 microhybrid composite resin was capped over low viscosity bulk-fill resins in 2 mm thickness (SA2, SA3). The resin specimens were light cured for 20 seconds and the color was measured and analyzed (n = 10). Color differences (DeltaE) between SA2 and A2, SA3 and A3 were also calculated. RESULTS: L* value was highest in SDR followed by SA2 and SA3. L* value of A2 and A3 was the lowest. a* value was lowest in SDR followed by SA2 and SA3, and A2 and A3 was the highest. b* value was lowest in SDR followed by A2 and SA2, and A3 and SA3 was the highest. DeltaE between A2 and SA2 (DeltaE = 3.4), and that between A3 and SA3 (DeltaE = 3.1) was lower than the perceptible color difference threshold of DeltaE = 3.7. CONCLUSION: DeltaE between low viscosity bulk-fill resin with a capping layer and microhybrid resin was lower than the perceptible color difference threshold.

Color stability of esthetic restorative material after topical fluoride application

AIM: Present study was conducted to compare the effect of topical fluoride agents on color change of three aesthetic restorative materials. MATERIAL AND METHODS: Restorative material used were Ketac Fill type II (GIC), Filtek Z350(Composite) and Beuttifull II (Giomer). Topical Fluorides used were Pascal (1.23% APF gel) and Fluoride Varnish (Bifluoride). 24 samples of each restorative material were prepared, which were divided into 8 each, among three groups. Treatment of Group A with APF gel, Group B with Varnish was done and Group C with distilled water which was used as a control, followed by immersing of samples in artificial saliva for 48 hr. Samples were then subjected to colorimetric analysis. Data collected was statistically analysed using one way ANOVA and Tukys Post Hoc Test. RESULTS: GIC showed statistically significant change in color in both APF and Varnish group compared to composite and Giomer after 48 hr. CONCLUSION: Present study concludes that Topical fluoride agents have detrimental effect on color of aesthetic restorative materials. Giomer was least effected out of the three restorative materials and this can be used as alternative to other restorative material.

Evaluation of non cyanide methods for hemoglobin estimation.

Background: The hemoglobincyanide method (HiCN) method for measuring hemoglobin is used extensively worldwide; its advantages are the ready availability of a stable and internationally accepted reference standard calibrator. However, its use may create a problem, as the waste disposal of large volumes of reagent containing cyanide constitutes a potential toxic hazard. Aims and Objective: As an alternative to drabkin`s method of Hb estimation, we attempted to estimate hemoglobin by other non-cyanide methods: alkaline hematin detergent (AHD-575) using Triton X-100 as lyser and alkaline- borax method using quarternary ammonium detergents as lyser. Materials and Methods: The hemoglobin (Hb) results on 200 samples of varying Hb concentrations obtained by these two cyanide free methods were compared with a cyanmethemoglobin method on a colorimeter which is light emitting diode (LED) based. Hemoglobin was also estimated in one hundred blood donors and 25 blood samples of infants and compared by these methods. Statistical analysis used was Pearson`s correlation coefficient. Results: The response of the non cyanide method is linear for serially diluted blood samples over the Hb concentration range from 3gm/dl -20 gm/dl. The non cyanide methods has a precision of + 0.25g/dl (coefficient of variation= (2.34%) and is suitable for use with fixed wavelength or with colorimeters at wavelength- 530 nm and 580 nm. Correlation of these two methods was excellent (r=0.98). The evaluation has shown it to be as reliable and reproducible as HiCN for measuring hemoglobin at all concentrations. The reagents used in non cyanide methods are non-biohazardous and did not affect the reliability of data determination and also the cost was less than HiCN method. Conclusions: Thus, non cyanide methods of Hb estimation offer possibility of safe and quality Hb estimation and should prove useful for routine laboratory use. Non cyanide methods is easily incorporated in hemobloginometers by using very minute quantities of reagents and test sample; hence, these methods can be used to provide point of care testing in blood banks for hemoglobin (Hb) estimation in blood donors.

Understanding of the color in composite resin / 대한치과보존학회지

In clinic, esthetic restoration of a defective natural tooth with composite resin is challenging procedure and needs complete understanding of the color of tooth itself and materials used. The optical characteristics of the composites are different because the chemical compositions and microstructures are not same. This review provided basic knowledge of the color and the color measurement devices, and analyze the color of the natural tooth. Further, the accuracy of the shade tab, color of the composite resins before and after curing, effect of the water, food and bleaching agent, and translucency, opalescence, and fluorescence effects were evaluated.

Características físico-químicas e sensoriais de marcas comerciais de queijo mozarela de leite de búfala / Physical-chemical and sensorial characteristics of marketed buffalo mozzarella cheese

No presente estudo foram avaliados os parâmetros físico-químicos e sensoriais de oito marcas de queijo Mozarela de búfala, analisando-se os teores de umidade, extrato seco total, lipídios, lipídios no extrato seco, proteínas, proteínas no extrato seco, cinzas, carboidratos, pH, digestibilidade in vitro de proteínas e β-caroteno. Realizou-se a análise instrumental da cor por meio de colorímetro Kônica Minolta CR 400. Sob o aspecto sensorial, foram feitos testes de ordenação de cor (branco claro – escuro), maciez (menos –mais), efetuados por 30 provadores, e preferência (gostei menos – gostei mais), realizado por 55 pessoas. As amostras de queijos analisadas apresentaram diferenças significativas nos parâmetros avaliados, com exceção da digestibilidade in vitro. Observou-se também a ausência de β-caroteno nas amostras de todas as marcas, o que indica que estão em conformidade com a legislação. Verificou-se que a variação na tonalidade branca não afetou a preferência, o que sugere que as marcas de produtos mais macios foram as mais aceita se que as variações encontradas estejam provavelmente associadas à variação da composição química da matéria-prima, bem como à forma de processamento do produto.

The sensorial and physical-chemical parameters of eight brands of buffalo mozzarella cheese were assessedanalyzing humidity rate, total dry extract, lipids, lipids in dry extract, proteins, proteins in dry extract, ashes, carbohydrates, pH, in vitro digestibility of proteins and β-carotene. The instrumental color analysis was performed by using Konica Minolta colorimeter CR 400. Sensorial color ordination tests (light – dark), softness (less - more) and preference (liked less – liked more) were performed by 30 testers, and the preference test by 55 persons. The cheeses samples from different brands showed significant differences in the evaluated parameters, except for in vitro digestibility. It was also found a lack of β-carotene in all of product brands, being in agreement with the legislation in force. The range of white tonality did not affect the preference; therefore, it was inferred that the softest product brands were the best accepted andthe softness variations were probably related to the chemical composition of raw material and also to the procedure for manufacturing the product.

The evaluation of clinical efficacy and longevity of home bleaching without combined application of In-office bleaching / 대한치과보존학회지

OBJECTIVES: The purpose of this study was to evaluate the whitening efficacy and longevity of home bleaching. MATERIALS AND METHODS: A total of 28 patients were divided into either experimental group (Opalescence F; 15% carbamide peroxide) or control group randomly. The patients in experimental group were instructed to wear individual trays applied with bleaching gel for 2 hours a day for 4 weeks. Any treatments weren't applied to the patients in control group. The color measurements of central incisors, lateral incisors & canines of upper and lower arch were recorded at base line, immediately after the finishment of treatmemt (4 weeks), 8 weeks and 12 weeks using Colorimeter (Chroma Meter, 2600d Konica Minolta co.) and Vitapan classical shade guide (Vita Zahnfabrik). RESULTS: A significantly stronger color change was observed for overall teeth samples in experimental group immediately after treatment (at 4 weeks) compared to ones in control group (p < 0.05). There was also a significant difference between baseline and 8 weeks or 12 weeks separately though color rebouncing phenomenon occurred as time went by (p < 0.05). CONCLUSIONS: The clinical effecacy and longevity of home bleaching without combined application of in-office bleaching was observed through this experiment.

Comparison on accuracy of porcelain color reproducibility using two colorimeters / 대한치과보철학회지

STATEMENT OF PROBLEM: Although the use of colorimeter to improve the accuracy of tooth color measurement has increased, it is real situation that there is almost no comparative study about the accuracy among various colorimeters. PURPOSE: The purpose of this study is to compare the accuracy of porcelain color reproducibility using ShadeEye-Ncc dental chroma meter (Shofu Inc., Kyoto, Japan) and Shadepilot(TM) system (Degudent Inc., Hanau, Germany). MATERIAL AND METHODS: Color of 2M2 and 3M2 shade tap of Vitapan 3D Master shade guide were measured using the above two colorimeters. Porcelain specimens were fabricated through this data. The porcelain systems used were Vintage Halo Porcelain system with ShadeEye-Ncc dental chroma meter, and VitaOmega900 Porcelain system with Shadepilot(TM) system. Colors of shade tap models and porcelain specimen were measured with spectrophotometer, and calculated delta E based on the results. RESULTS: The following results were obtained. 1. Shadepilot(TM) system showed more suitable porcelain color reproducibility compared to ShadeEye-Ncc dental chroma meter (P < .05). 2. The result showed the difference of porcelain color reproducibility according to shade of Shade tap which is model. More suitable porcelain color reproducibility was shown at 3M2 shade tap than at 2M2 shade tap (P < .05). 3. The average of DeltaE* of porcelain specimens which was made by the two colorimeters was 4.44-6.14, so the difference of shade was shown through the naked eye. CONCLUSION: Shadepilottrade mark system showed more suitable porcelain color reproducibility. When using ShadeEye-Ncc dental chromameter, it will be necessary to improve accuracy through coloring various parts of the whole tooth.

Influence of the color of composite resins applied to lingual surface on the labial tooth color / 대한치과보존학회지

In this study we evaluated the influence of both the thickness of residual enamel and the color of the composite resins applied to lingual surface on the labial surface color. Background plates were made by randomly (A1, A2, A6D, B1, B2, B3, C1, C2, C6D) selected colors of Filtek Supreme (3M ESPE, St. Paul, U.S.A.) composite resin. Crown portion of 9 maxillary central incisors were cut off and embedded with acrylic resin except labial surface. Samples of average thickness of 2.2 mm were obtained after cutting it in a thickness of 2.5 mm from the labial surface and sandpaper polish. The shade of composite resin background was measured using Spectrophotometer (Spectrolino(R) GretagMacbeth, Regensdorf, Switzerland). And CIE L*a*b* value of 2.2 mm thickness tooth samples were measured on the 9 composite resin backgrounds. And then, the cutting side of tooth samples was ground to the extent of 1.9 mm, 1.6 mm, 1.3 mm, 1.0 mm and placed on composite resin backgrounds and measured L*a*b* values with the same method. In all samples, L* value and b* value seemed to have a tendency of decreasing as thickness of tooth sample becomes thinner regardless of background colors (p < 0.05). But, a* value didn't show the significant differences depending on the thickness.

Color difference of the dental composites measured by different color measuring instruments / 대한치과보존학회지

The objective of this study was to evaluate the effect of color measuring instrument by measuring the color of dental composite resins. Nine shade light cured composite resin disks were prepared (diameter : 15 mm, thickness : 4 mm). CIE L*a*b* color scale of each disk was measured with 3 different types of spectrophotometer [MiniScan XE plus (Model 4000S, Hunter Lab, USA), CM-3500d (Minolta, Japan) and Specbos 2100 Miniature VIS Reflection spectrometer (Serial No: 319416, JETI Technishe VIS Instrumentic GmbH, Germany)]. Miniscan XE Plus and CM-3500d using identical measuring geometry with different size of viewing aperture. But Specbos 2100 using different measuring geometry. Within the limitation of this study, there were color difference (DeltaE*) from 2.4 to 7.8 between Miniscan XE Plus and CM-3500d, but L*, a*, b* values showed the high correlation. However, there were great color difference (DeltaE*) in the extent of about 20 between instruments with the different measuring geometry. Therefore, color scale measured by color measuring instrument should be used as a relative value rather than an absolute value in the field of dentistry.

Comparison of shade changes according to dry/wet condition of teeth using intra-oral colorimeter / 대한치과보철학회지

OBJECTIVES: The purpose of this study was to compare the shade changes in wet and dry conditions of natural teeth using two different intra-oral colorimeters. MATERIALS AND METHODS: Twenty volunteer subjects have no restorations and fillings in the maxillary central incisors were involved in this clinical study. The color of tooth was measured by two different instruments that were a Shade Scan(TM) System and a VITA Easyshade(R), Five times consecutive measurements were done for each subject with both instruments. Groups of measurement are an initial wet condition as control, dry in 5 minutes, 15 seconds after re-wetting with saliva, re-wetting after 5minutes and re-wetting after 30 minutes. Using ShadeScan System(TM), tooth image was captured and converted to the mapping image of Vitapan 3D master. Three main shades were chosen from each subject and calculated the area in Global Lab Image software. Data were analyzed using paired T-Test and Wilcoxon Signed Ranked Test. Using VITA Easyshade(R), color differences(deltaE) between measurements were analyzed with one sample T-test. RESULTS: Using ShadeScan System(TM), there were significant differences between control group and dry(P=.023), dry and re-wetting 15 seconds, 5 minutes, 30 minutes as well(P=.021, P=.017, P=.030) in comparison of primary shade. However, comparing three main shades, there was no significant difference between control and dry(P=.105). Using VITA Easyshade(R), color differences(deltaE) between control and dry, dry and re-wetting 30 minutes were statistically different(P=.002, P=.022). CONCLUSION: Primary shade could be changed in dry and wetting procedure in time, however there was no significant shade changes in overall.

A study on the color stability of porcelain repair resins / 대한치과보철학회지

STATEMENT OF PROBLEM: Porcelain restorations are widely used in restorative dentistry with a high degree of general success. However, porcelain is brittle and may fracture intraorally. Sometimes a repair may be attempted using composite resin and bonding system available. Color stability of porcelain repair resins affects esthetics and prognosis of prosthesis, so that provides important criteria for the choice of porcelain repair resins. PURPOSE: The purpose of this study was to investigate the color stability of composite resins used widely as porcelain repair system. MATERIALS AND METHOD: Composite resins used for this study were Carisma(Kulzer, Germany), Tetric ceram(Ivoclar, Liechtenstein), Filtek Z250(3M, USA), and Arabesk Top(VOCO, Germany). Thirty disc-shaped specimens(10x2mm) were fabricated from each composite resin. Color changes of specimens after treatment using thermocycling system(KD-TCS30, Kwang-duk F.A. Korea) and after immersion in methylene blue(0.05% by Wt) were measured with colorimeter(Model Tc- 6Fx, Tokyo Denshoku Co.) and obtained data were analyzed. RESULTS AND CONCLUSION: The results obtained from this study were as follows. 1. The color change of Filtek Z250 was lesser than those of Tetric ceram and Arabesk Top after thermocycling (12000 times). 2. All of the composite resins in this study showed increase of color change according to increase of thermocycling frequency. 3. After treatment with methylene blue, the color change of Arabesk Top was greater than those of Carisma and Tetric ceram, and Tetric ceram was more stable than others.

The Study On The Color Stability Of Composite Resin / 대한치과보철학회지

The purpose of this study was to investigate the color stability of composite resins used widely as esthetic restorative material.Surefil(Dentsply,U.S.A.),Esthet X(Dentsply,U.S.A.),Filtek P60(3M,U.S.A.),Filtek Z250(3M,U.S.A.),Synergy Compact(Coltene,Switzerland),and Synergy Duo(Coltene,Switzerland)were chosen for this study.Thirty six specimens(7mm x2mm) of each composite resin were fabricated and polished after polymerization.Treatment conditions designed for this study were thermocycling,methylene blue staining,and filtered coffee staining. The color changes before and after treatment were measured by colorimeter(colorimeter,Model Tc-6Fx,Tokyo Denshoku Co.)and analyzed. The followings were drawn from this study: 1.The color changes of Filtek Z250,Surefil,Filtek P60 and Esthet X after thermocycling for 3 weeks were greater than those of the others. 2.The color changes of Surefil and Esthet X after methylene blue staining and those of Surefil, Filtek Z250 and Filtek P60 after coffee staining were great. 3.The color changes of Synergy Duo and Synergy Compact after thermocycling and coffee staining were relatively lesser than those of other composite resins.