Chlorpheniramine meleate (CM) is a antihistaminic agent. Assay for chlorpheniramine meleate in the multi-component drugs by colorimetry method. A technique was proposed to increase the accuracy of the assay for chlorpheniramine meleate. The assay of the method is about 2%
Chlorpheniramine ; Pharmaceutical Preparations ; Colorimetry

OBJECTIVETo investigate the influence of different intensity and directions of ambient light and adjacent tooth in anterior tooth color measurement by using colorimeter.

METHODSFiber lite MI-150 was used as ambient illuminant and it irradiated from three or twelve o'clock direction through 45 degrees angle above. The light magnitude 0, 50, 75, 100, 125, 150 W were applied in this experiment. The values of CIE L* a* b* were measured by Minolta Chroma meter CR-321 colorimeter on the center labial surface of ten extracted human maxillary central incisors with or without adjacent teeth, then those data were analyzed statistically by using SPSS 11.5.

RESULTSNeither different intensities nor different directions of ambient light could influence the results of color measurement by using Minolta Chroma meter CR-321 colorimeter, so did the adjacent teeth whether those were exist or not.

CONCLUSIONThere is no influence of ambient light and adjacent teeth in the color measurement of anterior teeth under this experiment condition, and Minolta Chroma meter CR-321 colorimeter can be used to measure the color directly aside the chair with light.

Colorimetry ; Humans ; Technology, Dental ; methods

From the leaf of lotus (Nelumbo nucifera), total alcaloids were extracted and purified in using chloroform in alcaline medium and 3% phosphoric acid solution.In mixing with bromothymol blue in buffer solution at pH=7, the complex was measured at λ =615± 1nm on spectrophotometer. For UV spectrophotometry, total alcaloids in solution were measured at λ=270nm
alkaloids ; Plant Leaves ; Lotus ; Spectrophotometry ; Colorimetry ;

Colorimetry ; methods ; Humans ; Manganese ; urine ; Potassium Permanganate

OBJECTIVETo evaluate the matching of the shade between beverage and modifying porcelain shade guide according to Munsell color order system, thus to provide the reference basis for selecting modifying porcelain to mimic the stain of natural tooth by technician.

METHODSThe shade of Vita Akzent, Vita Interno, Shofu Vintage & Unibond and Noritake Super Porcelain EX-3 shade tabs as well as 15 kinds of beverage were measured according to Munsell color order system on Color-Eye 7000A spectrophotometer. The difference of the frequency of approximate hue, value, and chroma between shade tabs and beverage were compared by calculating the Fisher exact probabilities.

RESULTSThe frequency of approximate hue between 4 kinds of shade tabs and 15 kinds of bev-erage was significant different (P<0.05), while the frequency of approximate value, and chroma was not significant different (P>0.05).

CONCLUSIONExcept the hue, the color distribution of 4 kinds of shade tabs was similar to that of 15 kinds of beverage. But the color of beverage also can be approximately matched by any kind of modifying porcelain by mixing porcelain powder of appropriate hue, value, and chroma.

OBJECTIVETo investigate the color stability and translucency of four composite resin cements after ultraviolet (UV) aging.

METHODS20 composite resin cement disks for four groups (Group A, dual cured, Biscem; Group B, light cured, Choice; Group C, self cured, PermaCem; Group D, self cured, RelyX Aplicap) were prepared according to their manufacture recommendation. Changes in color and translucency of test samples were determined before and after UV aging for 8, 16 and 24 hour using the CIE L* a* b* system by a colorimeter. The results were analyzed by LSD multi-compare tests.

RESULTSThe color changes of composite resin cement disks suffering UV aging were significantly different when irradiated different time. For the same irradiated time, Group C had the highest delta E, and Group B and D had the smaller ones. Translucency was found no difference among different irradiated time for group A, B and D. Translucency of group C decreased after UV aging.

CONCLUSIONTranslucency of composite resin cement kept stable after UV aging, and color coordinate changed after UV aging.

OBJECTIVETo research the color space of the standard color board, guide the clinic work of color match, and establish an foundation for deeper researching.

METHODSThrough taking analysis of reflecting spectrum and spectral tristimulus, each parameter of the color on standard board was found out. The color difference between border upon colors on board was worked out through matching the color parameters. The number of color space between each border upon color on standard color board, divided by deltaE = 1.5, was found.

RESULTSThe number of color space between each border upon color was 3-6. The color space was bigger in group B, but smaller in group D. The color space was bigger in high lightness area, but smaller in low lightness area.

CONCLUSIONSome color space has been found between standard color borders of VINTAGE and UNIBOND. Color of natural teeth is unable to be completely included into standard color border, especially in clinical care.

OBJECTIVE: In our previous study, glass-fiber-reinforced plastics (GFRPs) made from polycarbonate and glass fibers were prepared for esthetic orthodontic wires using pultrusion. These laboratory GFRP wires are more transparent than the commercially available nickel-titanium wire; however, an investigation of the color stability of GFRP during orthodontic treatment is needed. Accordingly, in the present study, the color stability of GFRP was assessed using colorimetry. METHODS: Preparation of GFRP esthetic round wires (diameter: 0.45 mm [0.018 inch]) using pultrusion was described previously. Here, to investigate how the diameter of fiber reinforcement affects color stability, GFRPs were prepared by incorporating either 13-microm (GFRP-13) or 7-microm glass (GFRP-7) fibers. The color changes of GFRPs after 24 h, and following 1, 2, and 4 weeks of coffee immersion at 37degrees C, were measured by colorimetry. We evaluated the color stability of GFRPs by two evaluating units: the color difference (DeltaE*) and National Bureau of Standards (NBS). RESULTS: After immersion, both GFRPs showed almost no visible color change. According to the colorimetry measurements, the DeltaE* values of GFRP-13 and GFRP-7 were 0.73-1.16, and 0.62-1.10, respectively. In accordance with NBS units, both GFRPs showed "slight" color changes. As a result, there were no significant differences in the DeltaE* values or NBS units for GFRP-13 or GFRP-7. Moreover, for both GFRPs, no significant differences were observed in any of the immersion periods. CONCLUSIONS: Our findings suggest that the GFRPs will maintain high color stability during orthodontic treatment, and are an attractive prospect as esthetic orthodontic wires.
Coffee ; Colorimetry ; Esthetics ; Glass ; Immersion ; Orthodontic Wires* ; Plastics*

OBJECTIVETo investigate the color stability and opacity of seven resin-based composite products after ultraviolet irradiation.

METHODSSeven kinds of light-cured resin-based composite products (Aelite Flo, Filtek Z350 Flowable, Clearfil AP-X, Dyract AP, Z100, Durafill VS, Filtek Z350 Universal) were tested in the study (five for each group). Changes in color and opacity of test samples were determined before and after 8, 16 and 24 h ultraviolet irradiation using the CIE 1976 L*a*b* system and CIE 1931 XYZ system by a colorimeter.

RESULTSThe color of resin disks suffering ultraviolet irradiation was different in different irradiating time. Color difference values ranged from 1.85-3.21 for 8 h ultraviolet irradiation to 2.88-4.55 for 24 h ultraviolet irradiation. Opacity values ranged from 0.75-0.82 before ultraviolet irradiation to 0.80-0.98 after 24 h ultraviolet irradiation. Among all the groups, Z100 and Filtek Z350 Flowable showed the biggest color change, while Filtek Z350 Universal showed the highest opacity.

CONCLUSIONIt can be concluded that for some products, ultraviolet irradiation leads to color instability and opacity variation.