Preliminary Result of Randomised Controlled Trial of Three Different Coated Archwires Part 2: Colour Change and Patient Perception

@#Introduction: Coated archwires improve aesthetics because of the tooth-coloured appearance. However, colour change of the coated archwires have been reported in vitro. Nonetheless, little is known to what extent this colour change occurs clinically. This second part of the multi-centre, double-blind, randomised controlled trial evaluated the colour change (∆E*) of three coated archwires with their controls and patient perception. Methods: 84 patients who received treatment with upper and lower fixed appliance treatment were invited. Consented patients were randomised to receive one of four treatment interventions using 0.014” superelastic nickel-titanium archwires from (1) Orthocare (2) RMO (3) G&H, and (4) 3M Unitek® uncoated. These archwires were ligated during bonding and collected after 8th week. After removal, the digital images of the archwires were assessed for colour change using Adobe® Photoshop® software, and the CIE L*a*b* system was used to calculate the ΔE* values. Patient perception was measured using oral aesthetic subjective impact scale (OASIS) questionnaire. Results: For colour change and patient perception assessment, 132 archwires from 66 participants who had been treated with aesthetic archwires were collected. Two fractured archwires were excluded. Initial analysis revealed all three aesthetic archwires groups showed significant mean of ∆E* with the highest was found in Orthocare (23.9), and the lowest is G&H (16.8). Post hoc comparison revealed statistically significant mean of ∆E* in Orthocare when compared with other groups (p <0.001). There was no statistically significant difference for patient perception between archwire groups. Conclusion: Preliminary results revealed that significant ∆E* in Orthocare group and patients showed positive perception following clinical use

Correlation study between specification of velvet antler and its color and chemical composition / 中国药学杂志

OBJECTIVE: To investigate the color and chemical composition of the wax slices, w-powder slices, r-powder slices, blood slices and bone slices of two-branch Velvet Antler, three-branch Velvet Antler and reborn Velvet Antler with different growth years, and analyze the relationship between the color characteristics and chemical composition (protein, polysaccharide, phospholipid). METHODS: The color parameters of five kinds of slices with different growth periods were detected by CIEL*a*b* color space. The content of protein was determined by Coomassie blue colorimetric method, the content of polysaccharide was determined by phenol sulfuric acid method, and the content of phospholipid was determined by molybdenum blue colorimetric method. Pearson correlation analysis was used to analyze the correlation between color and components. RESULTS: There were significant differences in color and chemical composition between the five types of Velvet Antlers with different grow periods. Pearson correlation analysis showed that the Velvet Antler color parameter b* had a significant negative correlation with the three chemical components. CONCLUSION: The color determination method based on the principle of colorimetry can effectively distinguish Velvet Antlers in different growth stages. And the correlation analysis showed that the color digital index can reflect the difference in chemical composition of Velvet Antler in a certain degree.

The influence of metal substrates and porcelains on the shade of metal-ceramic complex: A spectrophotometric study.

Background: The final esthetic outcome of a metal-ceramic restoration is influenced by several factors including the type of the underlying metal as well as the brand of the ceramic. Settings and Design: An in vitro study. Aims: The purpose of the in vitro study was to investigate the influence of four types of metal-ceramic alloys and two porcelain systems on the color co-ordinates of the metal-ceramic complex. It also aimed at establishing a color index which correlated the color of the metal-ceramic combination to the yellow-blue axis. Materials and Methods: Twenty-four disc-shaped metal specimens of 12 mm × 1 mm were cast from base metal alloys, nickel-chromium (Ni-Cr) (Wiron 99), cobalt-chromium (Co-Cr) (Wirobond C), a palladium (Pd)-rich noble metal alloy (Spartan Plus), and a high noble gold (Au) alloy (Pontostar). These discs were covered with two commercially available feldspathic porcelains (Vita Omega and Shofu Vintage) of A3 shade to a total thickness of 1.2 mm. Each group had six specimens, of which three were coated with Vita Omega and the remaining with Shofu Vintage. Opaque and dentin layers were applied to a standardized thickness of 0.2 mm ± 0.05 mm and 1 mm ± 0.05 mm, respectively onto the metal surface after air abrasion with 50 μm alumina particles. The reflectance spectra were measured with a spectrophotometer and data were recorded in L*, a* and b* coordinates in the CIE Lab Color Order System. Statistical Analysis: Analysis of variance (ANOVA) and path analysis were the statistical tools employed to analyze the data. A critical difference (CD) value was calculated for each color co-ordinate to make comparisons between each metal-ceramic combination. A color index for each metal-ceramic complex was also calculated from the color co-ordinates obtained. Results: ANOVA revealed that significant differences existed between the metal-porcelain combination at 0.01 ( P < 0.01) level. The L* value was significantly higher for Au and Co-Cr alloys with Vita Omega porcelain. The a* value was highest for Ni-Cr alloy when combined with Shofu Vintage ceramic. The b* value of Au alloy with Vita Omega porcelain was significantly higher than any other metal-ceramic combination. The color co-ordinates of Pd alloy with both porcelain systems did not show any significant differences. Gold alloy with Vita Omega showed the highest color index value. Conclusion: The variations in metal-ceramic alloy and porcelain can influence the shade of a metal-ceramic restoration. Color index value was the highest for gold alloy.

The evaluation of color and color difference according to the layering placement of Incisal shade composites on the body composites of the indirect resin restoration / 대한치과보존학회지

OBJECTIVES: The aim of this study was to evaluate the surface color of indirect resin restoration according to the layering placement of different shade of incisal composite. MATERIALS AND METHODS: In this study, CIE L*a*b* value of 16 Body composite of Tescera ATL (Bisco, Schaumburg IL,USA) was measured by spectrophotometer (NF999, Nippon Denshuku, Japan), and compared to CIE L*a*b* value of Vitapan shade guide. Nine shade Incisal composite of Tescera ATL were build-up to 1 mm thickness on Body composites inlay block, and CIE L*a*b* value was measured. Incisal composite was ground to 0.5 mm thickness and CIE L*a*b* value was re-measured. Color difference between Body composite and Incisal composites layered on Body composite was calculated as a function of thickness. RESULTS: Color difference between corresponding shade of Tescera Body composite and Vitapan shade guide was from 6.88 to 12.80. L* and b*value was decreased as layering thickness of Incisal composite on Body composite was increased. But, a* value did not show specific change tendency. CONCLUSIONS: Surface color difference between Body composites and Incisal composites layered on Body composite was increased as the layering thickness of Incisal composite increased (p < 0.05).

Color stability of the resin cements with accelerated aging / 대한치과보존학회지

The purpose of this study was to evaluate the color stability of resin cements with accelerated test. Four dual curing resin cements: Panavia-F (KURARAY), Duolink (BISCO), Variolink-II (Ivoclar Vivadent), and RelyX Unicem (3M ESPE) and 1 self curing resin cement: Resiment CE (j. l. Blosser) were used in this study. In control group, Gradia Anterior (GC) composite resin and Tescera Dentin (Bisco) indirect composite were used. Ten disk shape specimens were made from each resin cement. The specimens were subjected to an accelerated aging process in a refrigerated bath circulator at 60degrees C for 15 and 30 days. Spectrophotometric analyses were made before and after 15 days and 30 days of accelerated aging time. The color characteristics (L*, a*, b*) and the color difference (DeltaE*) of the specimens before and after immersion were measured and computed. Regardless of type of the resin cements, L* value was decreased and a* value was increased, but there were no significant difference. But b* value was increased significantly (p < 0.05). Tescera inlay showed least color change (p < 0.05), but Gradia showed notable color change after 15 days. After 30 days on accelerated aging, DeltaE* value was increased (Panavia-F < Variolink-II < Resiment CE < Duolink < Unicem) (p < 0.05), but there were no significant difference among Panavia-F, Variolink-II, and Resiment CE groups. After 30 days of accelerated aging, DeltaE* value of all resin cements were greater than 3.0 and could be perceived by the human eye.

Caracterizacióndde las propiedades y la estabildad del color de soluciones de los antranoides prenilados ferruginina a y ?-hidroxiferruginina a / Characterizatio of colour properties and stability of solutions of prenylated anthranoids ferruginin a and ? -hydroxyferruginin a / Caraterizaçãodass propriedades e a estabilidade da cor das souções dos antraanoides prenilados ferruginina a e ? -hidroxiferruginina a

Se evaluaron las propiedades del color y la estabilidad a diferentes factores (temperatura y pH) de soluciones de los antranoides prenilados ferruginina A (FRA) y ?-hidroxiferruginina A (HFA), obtenidos a partir de las bayas de las especies Vismia guianensis y V. baccifera ssp. ferruginea. El estudio de la influencia de la temperatura sobre las características espectrales reveló que las soluciones en propilenglicol de la FRA y la HFA son relativamente estables al calor a las temperaturas de 50 y 80 °C , mientras que a 100 y 150 °C presentaron cambios ligeros en la intensidad (e) y tonalidad (?vis-max, coordenadas colorimétricas CIE L* a* b*). Adicionalmente, las variaciones del color (?vis-max, e) para los antranoides en el rango de pH 1,0-11,0 durante 60 días de almacenamiento a 4 y 25 °C , demostraron una mayor estabilidad del color en condiciones de refrigeración y pH 6,0 y 8,0, la cual fue superior para las soluciones de HFA. Las buenas características de los compuestos los hacen potencialmente útiles como colorantes naturales en la industria de los cosméticos, textil y farmacológica.

Colour properties and stability to different factors (temperature and pH) of solutions of prenylated anthranoids ferruginin A (FRA) and ? -hydroxyferruginin A (HFA), obtained from berries of Vismia guianensis and V. baccifera ssp. ferruginea, were evaluated. Spectral characteristics influenced by different temperatures, revealed that the solutions in propylenglycol of the FRA and HFA were relatively stable to the heat to temperatures of the 50 and 80 °C , whereas to temperatures of 100 and 150 °C they displayed slight changes in the intensity ( e ) and tonality ( ? vis-max, colorimetric co-ordinates in the CIE L* a* b* scale). Additionally, colour variation ( ? vis-max, e ) for both anthranoids in the pH range 1.0 - 11.0 during a period of 60 days storage at 4 and 25 °C , showed higher colour stability in refrigerated conditions and pH values of 6.0 and 8.0, being better for solutions of HFA. The good characteristics of compounds make them potentially useful like natural colourants in the textile, cosmetic and pharmacological industry.

Foram avaliadas as propriedades da cor e a estabilidade de fatores diferentes (temperatura e pH) de soluções dos antranoides prenilados ferruginina A (FRA) e ? -hidroxiferruginina A (HFA), obtidos das bagas das espécies Vismia guianensis e V. baccifera ssp. ferruginea. O estudo da influência da temperatura nas características espectrais mostra que as soluções em etilenglicol da FRA e a HFA foram relativamente estáveis ao calor para as temperaturas de 50 e 80 °C , enquanto para temperaturas de 100 e 150 °C apresentaram mudanças leves na intensidade ( e ) e tonalidade ( ? vis-max, coordenadas CIE L* a* b*). Além do mais, as variações da cor ( ? vis-max, e ) dos antranoides no rango de pH 1,0-11,0 durante 60 dias de armazenamento a 4 e 25 °C mostraram uma estabilidade maior em condições refrigerasão e em valores de pH de 6,0 e de 8,0, sendo melhor para soluções do HFA. As características boas dos compostos os fazem potencialmente úteis como corantes naturais nas indústrias das cosméticas, têxtil e farmacêutica.

Proposal of new dental color-space for aesthetic dental materials / 대한치과보존학회지

The purpose of this study is to develope new dental color-space system. Twelve kinds of dental composites and one kind of dental porcelain were used in this study. Disk samples (15 mm in diameter, 4 mm in thickness) of used materials were made and sample's CIE L*a*b* value was measured by Spectrocolorimeter (MiniScan XE plus, Model 4000S, diffuse/8degrees viewing mode, 14.3 mm Port diameters, Hunter Lab. USA). The range of measured color distribution was analyzed. All the data were applied in the form of T### which is expression unit in CNU Cons Dental Color Chart. The value of L* lies between 80.40 and 52.70. The value of a* are between 10.60 and 3.60 and b* are between 28.40 and 2.21. The average value of L* is 67.40, and median value is 67.30. The value of a* are 2.89 and 2.91 respectively. And for the b*, 14.30 and 13.90 were obtained. The data were converted to T### that is the unit count system in CNU-Cons Dental Color Chart. The value of L* is converted in the first digit of the numbering system. Each unit is 2.0 measured values. The second digit is the value of a* and is converted new number by 1.0 measured value. For the third digit b* is replaced and it is 2.0 measured unit apart. T555 was set to the value of L* ranging from 66.0 to 68.0, value of a* ranging from 3 to 4 and b* value ranging from 14 to 16.

Influence of the labial surface irregularity on the measurement of the tooth color by spectrometer / 대한치과보존학회지

The most scientific and reliable method for deciding the tooth color is the instrumental measurement. However, such color measuring instrument shows the difference of the measuring value according to the diversified measuring condition. This study was conducted to evaluate what effect of the labial surface irregularity of the tooth to the result of the color measured by spectrometer. 11 models of the teeth were made by injecting the A2 shade Luxatemp Automix Plus (DMG, Germany) into the impression acquired from 11 adults. Standard disk samples (15 mm diameter, 7 mm thickness) were made with same material. CIE L*a*b* value was measured at the incisal, central, and gingival area of the central incisor, lateral incisor, canine and first premolar using Specbos 2100 (JETI, Germany) spectrometer. Color difference was calculated between labial surface and standard samples. Among all models of the teeth, L* and b* value showed the reducing tendency as they go toward the gingival area, but a* value showed the increasing tendency. Color difference between model teeth and standard samples showed the most difference at the incisal area, but the gingival area showed the least difference. And the canine showed the least color difference from the comparison of standard sample, and the central incisor showed the highest difference (p < 0.01). Although the visually detectable difference of the measuring value showed notably depending on the type and measured area (p < 0.05), L* and a* value showed notable differences depending more on the measured areas than on the type of the teeth.