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

Colorimetry ; Humans ; Technology, Dental ; methods

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 ; methods ; Humans ; Manganese ; urine ; Potassium Permanganate

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.

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.

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 ;

OBJECTIVETo evaluate the effect of repeated sintering on the color and translucency of dental lithium disilicate-based glass ceramic.

METHODSThirty disc specimens (10 mm in diameter, and 1.00 mm ± 0.01 mm in thickness) were fabricated using an IPS e.max Press HT A2 ingot and then randomly divided into six groups (SO, S1, S2, S3, S4, and S5) (n = 5). Each group was sintered 0, 1, 2, 3, 4, and 5 times individually according to the manufacturer's recommendation. After polishing, ultrasonic cleaning, and drying, the color parameters (L*, a*, and b* values) and transmittance (τ) of all the specimens were measured using a ShadeEye NCC dental colorimeter and a TM-2 spectrophotometer, respectively. Subsequently, C*ab and ΔE were calculated. The results were statistically analyzed using SPSS 17.0 software for ANOVA and LSD.

RESULTSAfter repeated sintering, the L* value significantly decreased (P < 0.05), and the a*, b*, and C*ab values initially increased and then decreased (P < 0.05). The color parameters (L*, a*, and b*) and the C*ab values of group S3 were higher than those of the other groups. The τ values initially increased and then decreased (P < 0.05), and these values were optimal when sintered twice. In terms of transmittance (τ), statistical differences existed between the following groups: S0 and S2, S0 and S3,.S2 and S5, and S3 and S5 (P < 0.05). Compared with group S0, the color differences ΔE were 0.89 minimally and 2.01 maximally after different sintering times, which can be clinically acceptable.

CONCLUSIONRepeated sintering can affect the color and translucency of the IPS e.max Press lithium disilicate-based glass ceramic, but the color difference can be clinically acceptable.

OBJECTIVETo investigate the influence of repeated sintering on the color of two porcelain-fused-to-titanium, and the differences between the two porcelains.

METHODSThirty samples were prepared and sintered for 9 times. The color of samples were measured following sintering 1, 3, 5, 7, 9 times by ShadeEye NCC colorimeter according to two brands of porcelains with CIE1976L*a*b* color system, and calculated relevant chrome, chromatism and hue, and statistical analysis.

RESULTSWhen two brands of porcelains were sintered 5 times, the color parameters had no significant change and sintered continuely, the color parameters of L* and a* had obvious changes, but can't be observed by eyes.

CONCLUSIONThe color parameters of titanium-porcelains have no significant change after repeated sintering.