Editorial Type:
Article Category: Research Article
 | 
Online Publication Date: 15 Sept 2023

Clinical Tooth Color Matching: In Vivo Comparisons of Digital Photocolorimetric and Spectrophotometric Analyses

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Page Range: 490 – 499
DOI: 10.2341/22-079-C
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SUMMARY

Objective

This study aimed to compare the tooth color matching of two dental colorimetric methods: the spectrophotometric analysis (SPM) and the standardized digital photocolorimetric analysis (DPC).

Methods

The color of 60 maxillary central incisors of 30 volunteers (22.5 ± 7.6 years) was analyzed. In the DPC method, tooth photographs were standardized with the eLABor_aid protocol, processed with Adobe Photoshop Lightroom software, and the values of L*, a*, and b* were obtained with a Digital Color Meter software. For the SPM, L*, a*, and b* were measured directly with a handheld spectrophotometer. Data were submitted to paired t-test and Pearson correlation test (α=0.05). Mean color difference between the two methods was calculated with CIELAB formula.

Results

All color coordinates revealed different values when comparing DPC to SPM in the same tooth (p<0.0001). Mean color difference (ΔEab) between SPM and DPC was 11.5 ±3.1. A positive correlation was observed for L* (R2=0.73,p<0.0001), a* (R2=0.31, p=0.017), and b* (R2=0.83, p<0.0001).

Conclusions

Even though the color coordinate values were different in both methods, they were correlated, revealing that the DPC is a viable alternative to determine the tooth color matching.

Copyright: 2023
Figure 1
Figure 1

Clinical setup for tooth photograph.

Figure 2
Figure 2

The picture is opened in the Develop mode at Adobe Photoshop Lightroom CC software (Adobe Systems Inc).

Figure 3
Figure 3

The software automatically recognizes the profile of the picture.

Figure 4
Figure 4

The profile has to be selected by clicking on it.

Figure 5
Figure 5

The white balance/color correction is performed by selecting the white Balance selector tool represented by the pipette symbol.

Figure 6
Figure 6

The white balance/color correction is completed by clicking on any of the four gray segments inside the semicircles of the card in the image

Figure 7
Figure 7

The exposure balance is corrected until the measured luminosity of the gray card matches the known luminosity of L* 79.

Figure 8
Figure 8

The L*a*b* values are measured using the Classic Color Meter.

Figure 9
Figure 9

The workflow for the camera settings, the shooting settings, and the software processing.

Figure 10
Figure 10

A silicone device and a tooth grading were used to standardize the spot where tooth color was analyzed.

Figure 11
Figure 11

The probe tip of the spectrophotometer was placed in the perforation at 90 degrees to the surface, in close contact.

Contributor Notes

*Corresponding author: Av Madre Benvenuta, 388 apt 1227b, Trindade - Florianópolis – SC, Brazil, Cep: 88036500; e-mail: analucia.p@ufsc.br
Accepted: 01 Jun 2023
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