Comparison of visual shade matching and photographic shade analysis

Abstract

Objective To compare the performance of a standardized photographic shade analysis (PSA) and visual shade matching (VSM) using two color difference formulas. Materials and Methods Fifty observers (35 undergraduate and 15 graduate students) evaluated the color of two upper left central incisors (LT—light tooth, and DT—dark tooth). VSM was performed using the VITA 3D Master (3D) shade guide in a controlled clinical environment. For PSA, a cross‐polarized filter and a gray card (Whibal) were used to standardize the photographs taken (target teeth and shade tabs from 3D). From the pictures obtained, the CIELAB coordinates, and color differences (normalΔEab* and ΔE00) were obtained. The shade tabs selected by two experienced researchers were conducted as part of the pilot study, and finally used as a standard for the analysis. Data were analyzed using descriptive statistics and the chi‐square test (p ≤ 0.05). Results Shade tabs selections of VSM and PSA agreed only for LT. The best “Match” selected by the researchers agreed with data from PSA using ΔE00. PSA using ΔE00 showed higher total percentages of “Match” and higher percentage of agreement among observers. A relationship was found for LT performing the PSA (p < 0.05). Conclusions The performance of the PSA was better than the VSM, but only when the CIEDE2000 color difference formula was used. Therefore, the color difference formulas influenced on the performance of PSA. Finally, the PSA improved the precision of the VSM. Clinical Significance To use a standardized PSA to improve the VSM and shade communication in clinical esthetic dentistry.

The role of interface distance and underlying substrate on the color adjustment potential of single‐shade composites

“…Although the use of images is not a validated method for color measurements, previous studies have shown that standardizing image acquisition and correcting white balance using a neutral gray card can yield reliable results comparable to those obtained with spectrophotometers. [17][18][19] Another important consideration is the conversion of RGB values to CIELAB color coordinates, which depends on factors like the illuminant and observer angle. 20,24 The choice of an appropriate illuminant was a key parameter in our study, as we aimed to evaluate the color match of single-shade composites to the surrounding substrate.…”

“…It is crucial to ensure accurate color representation in the photographs to obtain reliable results, like those using devices specifically designed for color assessment (e.g., colorimeters). Although the use of images is not a validated method for color measurements, previous studies have shown that standardizing image acquisition and correcting white balance using a neutral gray card can yield reliable results comparable to those obtained with spectrophotometers 17–19 . Another important consideration is the conversion of RGB values to CIELAB color coordinates, which depends on factors like the illuminant and observer angle 20,24 …”

“…However, previous studies have used spectrophotometers that do not allow for the measurement of color in different areas of the specimen 9–12,16 . In contrast, digital methods based on imaging systems and software, such as DSLR cameras combined with a white balance gray card, allow for the measurement of the color of diverse and small areas of a specimen 17–19 …”

“…[9][10][11][12]16 In contrast, digital methods based on imaging systems and software, such as DSLR cameras combined with a white balance gray card, allow for the measurement of the color of diverse and small areas of a specimen. [17][18][19] Therefore, the present study aimed to evaluate the effect of the distance from the composite interface and an underlying chromatic substrate on the CAP of two single-shade composites. The hypothesis is that the CAP would increase closer to the composite interface and over a chromatic background.…”

Three‐dimensional representation of the Vita Toothguide 3D‐Master: An in vivo clinical study

“…Despite the Vita Toothguide 3D‐Master having been used in several studies, 24,30,41,47–49 no three‐dimensional spatial representation of the 26 physical shade tabs, based on their color coordinates recorded in vivo, had been published prior to this research. Studies with which the present findings may be directly compared are therefore lacking.…”