OBJECTIVETo compare the color character of VITA shade guide and the custom shade guide with metal substrate.

METHODSColor of 9 sites of 5 series of VITA shade guides and custom shade guides with metal substrate were measured by means of PR-650 spectrophotometer.

RESULTSThe color range of VITA shade guide were that L* was 56.86-73.86, a* was-1.29-3.69, b* was 7.09-21.94, and the transparence was 3.20-7.59. The color range of the custom shade guide was that L* was 60.59-78.54, a* was -1.09-4.99, b* was 7.60-22.35, and the transparence was 0.23-10.98. L*, a* and b* of the custom shade guide with metal substrate were higher than VITA shade guide, and the transparence was differet. The color difference of homonymy shade tab between custom shade guide and VITA shade guide was larger than 1.5 NBS.

CONCLUSIONThere is color difference between VITA shade guide and custom shade guide. Metal substrate has effects on the color of cero-metal prosthesis, and color selection in clinic should be carefully considered.

Color ; Dental Prosthesis Design ; Prosthesis Coloring ; Spectrophotometry

OBJECTIVE: This study aimed to compare the effect of D55 and D65 light sources on the visual colorimetry performance of dental students by using a homemade light-source shelf. METHODS: Two Vitapan 3D-Master shade guides were randomly selected. One set was used as shade guides. Ten commonly used shade tabs of 2L2.5, 2M2, 2R2.5, 3M2, 3R2.5, 3L1.5, 3R1.5, 3L2.5, 4R1.5, and 4L1.5 were selected from the other set with covered value marks and numbered from 1 to 10. After the colorimetric training, 49 undergraduate dental students were randomly divided into two groups. Each student randomly selected two of the 10 shade tabs, and the colors were subsequently matched under D65 and D55 light sources from a distance of approximately 40 cm. The average color difference (ΔE) between the color selected by each participant and the actual color of shade tabs was calculated. Paired t test was used for statistical analysis. RESULTS: The ΔE values between the color selected by each participant and the actual color of the shade tabs under the D55 light source varied from 0 to 6.540. The average value was 2.501. The ΔE values between the color selected by each participant and the actual color of the shade tabs under the D65 light source varied from 0 to 6.610. The average value was 2.530. No statistically significant difference was observed between the results under the two light sources (P=0.921). CONCLUSIONS Both D55 and D65 daylight lamps can be used for daily dental colorimetry. These two different color temperatures showed no significant difference.
Color ; Colorimetry ; Dental Prosthesis Design ; Humans ; Prosthesis Coloring ; Students, Dental

OBJECTIVETo compare visual and spectrophotometric shade matching using Vita Easyshade and to evaluate its accuracy.

METHODSOne hundred and twenty participants with single anterior full ceramic restorations were included in this study. Subjects were randomly assigned to 2 groups, the visual shade matching group (Group V) and the spectrophotometric shade matching (Vita Easyshade) group (Group S). In each group, subjects were allocated into 2 subgroups, those matched with shade tabs (V1, S1) and those out of shade tabs (V2, S2). Following the treatment, the Commission International de I'Eclairage Lab parameters were tested using the spectrophotometric, and the DeltaEab* between the restoration and contrast teeth was calculated.

RESULTSThere were significant differences between DeltaEab*V (3.92 +/- 1.59) and DeltaEab*S (2.23 +/- 0.96), and also between DeltaEab*V2 (4.42 +/- 1.42) and DeltaEab*S2 (2.27 +/- 1.01), DeltaEab*V1 (2.29 +/- 0.88) and DeltaEab*V2 (P < 0.01). There was no significant difference between DeltaEab*V1 and DeltaEab*S1 (2.12 +/- 0.84) (P = 0.698), nor between DeltaEab*S1 and DeltaEab*S2 (P = 0.014).

CONCLUSIONSSpectrophotometric (Vita Easyshade) shade matching method is more accurate than visual shade matching when used on tooth that has out-of-shade-tab colour expression. It provides better colour reappearance, than does visual colour matching.

Adult ; Dental Prosthesis Design ; Esthetics, Dental ; Female ; Humans ; Male ; Middle Aged ; Prosthesis Coloring ; methods ; Spectrophotometry

OBJECTIVETo analyze the limitation of currently used shade guide systems comparing with color range of nature teeth.

METHODSDigital pictures of shade guide systems A (VITAPAN Classic), B (VINTAGE Halo), C (3D-MASTER), and 322 central incisors were taken under the same condition as light source of D65 with the observation method of d/0 degrees. The data obtained from nature tooth color were compared with the color range of three shade guide systems mentioned above in items of L * a * b */C * H degrees.

RESULTSThe normal chroma value (95%) of the natural teeth were L* 61.631-73.250, a * -0.719-1.879, and b * 8.701-17.790. Natural tooth colors were different from those of the shade guide system A which color range was narrower, short of red hue, higher values, and unevenly distribution of saturation. On the other hand, the range of red hue increased in shade guide system B while its saturation was slightly high. The color range of shade guide system C was greatest among the three shade guide systems. The saturation and value of shade guide system C covered all varieties of nature teeth measured in this research, but it still lacked red hue comparing to the nature teeth.

CONCLUSIONSComparing the color range of nature teeth, the shade guide systems used in clinic have uneven hue distribution and cannot cover all colors of nature teeth. Generally, all the shade guide systems are lack of the hues which are named under the category of red tone.

Adult ; Colorimetry ; methods ; Dental Prosthesis Design ; Female ; Humans ; Incisor ; Male ; Prosthesis Coloring ; Young Adult

OBJECTIVETo compare color parameters and transmittance of Y2O3 stabilized tetragonal zirconia polycrystals (Y-TZP) all-ceramic restorations using different veneering technologies.

METHODSFifteen disc specimens with 10 mm in diameter and (0.50 +/- 0.01) mm in thickness were fabricated of IPS e. max ZirCAD core material, and ZL1 IPS e. max ZirLiner was layered in 0.10 mm thickness. The specimens were divided into three groups randomly (n=5 per group). Group ZP was veneered 0.60 mm by heat-pressing; group ZC was veneered 0.60 mm by layering; group ZPC was veneered 0.30 mm by heat-pressing and then 0.30 mm by layering. Color parameters L*, a*, b* and transmittance of zirconia specimens were measured before and after veneering with ShadeEye NCC dental chromameter and spectrophotometer. Color saturation C* ab and color difference deltaE were calculated in the following formulae: C* ab = [(a*)2 + (b*)2](1/2), deltaE = [(deltaL*)2 + (deltaa*)2 + (deltab*)2](1/2) One-way analysis of variance and Turkey's multiple comparison test were used to analyze data (alpha = 0.05) by SPSS 10.0 statistic software. Color parameters of A2 shade tabs were measured, and color differences between each group and tab were calculated.

RESULTSAs to ZP,ZPC,ZC groups, the value of a* increased (-1.35 +/- 0.07, -0.64 +/- 0.06, -0.36 +/- 0.05) (P < 0.05), the value of b* decreased (27.01 +/- 0.07, 25.48 +/- 0.11, 23.28 +/- 0.25) (P < 0.05), and the value of C* ab decreased (27.04 +/- 0.08, 25.49 +/- 0.11, 23.28 +/- 0.25) (P < 0.05). L* and transmittance were maximum in ZP group (87.53 +/- 0.48, 1.64 +/- 0.03) and minimum in ZPC group (82.14 +/- 0.18, 1.47 +/- 0.01) (P < 0.05). Compared with standard A2 shade tab, the color difference of ZC group was minimum (delta = 1.04), and the color difference of ZP group was maximum (deltaE = 4.86).

CONCLUSIONSY-TZP all-ceramic restoration veneered by heat-pressing was the most transparent and lightest; while veneered by both heat-pressing and layering, the restoration was worst in translucency and the least light. The color of zirconia all-ceramic restoration veneered by layering was the most similar to standard shade tab, and the color difference was minimum.

Dental Porcelain ; chemistry ; Dental Prosthesis Design ; Hot Temperature ; Materials Testing ; Prosthesis Coloring ; Technology, Dental ; methods ; Zirconium ; chemistry

OBJECTIVETo determine the infinite optical thickness of dentine porcelain of IPS E.max A color series.

METHODSCylindrical dentine porcelain specimens of the IPS E.max A color series were prepared with a diameter of 13 mm and thickness of 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 mm. The chromatic value of all the specimens was determined with CM-5 spectrometer against standard black and white background. The chromatic aberration (deltaE) was calculated by regression equation.

RESULTSThe infinite optical thickness of dentine porcelain of the IPS E.max A color series ranged from 2.341 to 3.333 mm for a deltaE of 1.0, and from 2.064 to 2.904 mm for a deltaE of 1.5. As the chromaticity or thickness increased, the influence by the background color decreased, and the color of specimens became gradually close to the intrinsic color.

CONCLUSIONThe thickness of the background dentine porcelain specimens must exceed its infinite optical thickness to represent the intrinsic color and avoid the influence by the extrinsic color.

Coated Materials, Biocompatible ; chemistry ; Crowns ; Dental Porcelain ; chemistry ; Dental Prosthesis Design ; Humans ; Prosthesis Coloring ; Tooth Preparation, Prosthodontic ; methods

OBJECTIVEThe purpose of this study was to evaluate the color masking ability of Computer Aided Design/Computer Aided Manufacture(CAD/CAM) machining ceramic Vita Mark II, this ability was affected by thickness and shade.

METHODSEach of 5 specimens of 0.5 mm, 1.0 mm and 1.5 mm Vita Mark II A3C/18 and A2C/18 were prepared and the color change was measured after the substrate simulating stained teeth was covered with the specimen.

RESULTSStatistically significant differences (P < 0.01) were recorded in the substrates covered with different thickness and shade of Vita Mark II. The color changes (delta E) were 15.181, 17.691, 19.667 and 15.653, 16.880, 18.002 after the substrates were covered with 0.5 mm, 1.0 mm and 1.5 mm Vita Mark II A3C/18 and A2C/18.

CONCLUSIONAs a dental material, CAD/CAM Vita Mark II has high quality to mask the underlying color. Being a veneer, the masking ability with A2C/18 is better than that with A3C/18, but being an inlay, the result is reverse.

Color ; Colorimetry ; Crowns ; Dental Porcelain ; Dental Prosthesis Design ; Denture, Partial, Fixed ; Humans ; Metal Ceramic Alloys ; Prosthesis Coloring ; standards

OBJECTIVETo investigate the color difference between Au-Pt alloy porcelain and Ni-Cr alloy porcelain.

METHODS30 metal-ceramic specimens with different dentin porcelain thickness were fabricated with two types of metal-ceramic alloy, each type of alloy had 15 specimens. L*, a*, b* were measured after opaque porcelain was applied, and dentin porcelain was fired 1, 3, 5, 7 times by MINOLTA CR-100. Then delta E was calculated which reflected the color difference between high-gold alloy porcelain and Ni-Cr alloy porcelain.

RESULTSComparing with Ni-Cr alloy porcelain, the color of Au-Pt alloy porcelain was reddish, yellowish and less bright. The delta E between high-gold alloy porcelain and Ni-Cr alloy porcelain in shade A2 was largest when opaque porcelain was applied. It decreased when dentin porcelain was applied. It became smallest when fired 3 times, and increased along with the increase of fire times. It was larger than 1.5 except firing 3 times. When dentin porcelain was applied, delta E which was larger than 1.5 among different dentin porcelain thickness decreased along with the increase of dentin porcelain thickness.

CONCLUSIONThe color difference between the two types of metal-ceramic alloy should be carefully taken into account in order to improve the quality of color matching.

Chromium ; Chromium Alloys ; Dental Porcelain ; Dental Prosthesis Design ; Gold Alloys ; Humans ; Metal Ceramic Alloys ; Nickel ; Platinum ; Prosthesis Coloring

This paper introduces the current development and challenges of vision prosthesis.
Prosthesis Design ; Visual Prosthesis

OBJECTIVETo study the effect of repeated firings on color of porcelain-fused-to-titanium restorations.

METHODSTwenty standard porcelain-fused-to-titanium specimens were made with Dentsply DETREY TiBond C3 and Dentaurum rematitan Til. Then they were fired 1, 2, 4, 7, and 10 times. Color measurement was done after each firing.

RESULTMost of the color parameters had no significant difference after firing except for a* and Hab. All the color difference among groups were smaller than 1.0 (deltaE < 1.0).

CONCLUSIONRepeated firings will not affect the color stability of porcelain-fused-to-titanium restorations.

Color ; standards ; Dental Porcelain ; Denture Design ; Humans ; Metal Ceramic Alloys ; Prosthesis Coloring ; methods ; Titanium