Dentin translucency and color evaluation in human incisors, canines, and molars

doi:10.1016/j.prosdent.2015.07.015

The Journal of Prosthetic Dentistry

Volume 115, Issue 4, April 2016, Pages 475-481

https://doi.org/10.1016/j.prosdent.2015.07.015 Get rights and content

Abstract

Statement of problem

For restorations with excellent esthetics, an understanding of the optical properties of human dentin is needed. Little information is available on the translucency and color parameters of dentin and its relationship to tooth type and position.

Purpose

The purpose of this in vitro study was to investigate the translucency and CIELab color coordinates of human dentin in both anterior (incisors and canines) and posterior teeth (molars) by using spectrophotometric and spectroradiometric assessment methods.

Material and methods

Uniformly thick specimens (2 mm) of midcoronal human dentin were taken from 33 central and lateral incisors, 7 canines, and 33 molars (all maxillary teeth). The CIELab color coordinates were measured with a clinical spectrophotometer (Easyshade Compact) and a noncontact spectroradiometer (SpectraScan PR-704). The translucency parameter (TP) was calculated. Bland-Altman plots and Wilcoxon signed rank tests for paired samples were used to assess the agreement of the 2 measurement techniques. The differences between anterior and posterior dentin specimens regarding color coordinates and the translucency parameter were analyzed using Mann-Whitney-Wilcoxon rank sum tests.

Results

Statistically significant differences between spectrophotometric and spectroradiometric measurements of the TP and CIELab color coordinates were found in both groups of dentin specimens (P<.05). TP values of molar dentin specimens were significantly higher than those of the anterior ones, regardless of the assessment method (P<.001). Dentin specimens of the anterior teeth exhibited higher L∗ values but lower a∗ and b∗ values on both black and white backgrounds compared with molar dentin specimens.

Conclusions

The dentin of anterior teeth was found to be lighter but less translucent and less chromatic than in molars, regardless of the assessment method used.

Section snippets

Material and Methods

This study was approved by the Ethical Board of the local University (no. 406). A total of 81 human maxillary teeth extracted for therapeutical reasons (33 central and lateral incisors, 7 canines, and 41 molars) were used in this study. All selected teeth were of above average sizes and free of conservative or prosthetic restorations, caries, or pathological discoloration. After extraction, all teeth were cleaned with brushes under a water jet and stored in distilled water at room temperature

Results

Bland-Altman plots charting differences between the TP values measured by spectrophotometry (SPHM) and spectroradiometry (SRM) relative to the mean TP measurements of the 2 methods for all 73 teeth is presented in Figure 2. For incisors and canines, differences between measurements of the 2 devices were smaller, centered around 0, compared with the differences for molars.

Means, medians, and standard deviations for all color coordinates and TP values registered with both measurement methods are

Discussion

The first null hypothesis of this study was rejected. Even though in an overall comparison of all dentin specimens no statistically significant differences in the TP were found between the 2 devices, compared by groups of teeth, the SRM registered significantly higher TP values for anterior teeth and significantly lower TP values for molars than those found by SPHM. The lack of statistical differences between the TP values measured by the 2 devices, in the case of the overall comparison of all

Conclusions

Within the limitations of this in vitro study, it was concluded that important differences exist between spectrophotometric and spectroradiometric measurements of all color coordinates of the same specimen and that human dentin from anterior teeth is lighter but less translucent than molar human dentin.

Acknowledgments

The authors thank Marioara Moldovan for fabricating dentin specimens, Maria del Mar Perez Gomez for coordination of specimen measurements, and Prof dr Mindra Badea for proofreading this article.

References (43)

W. Culpepper
A comparative study of shade matching procedures
J Prosthet Dent
(1970)
R.C. Sproull
Color matching in dentistry. Part I: the three dimensional nature of color
J Prosthet Dent
(1973)
R.C. Sproull
Color matching in dentistry. Part II: practical applications of the organization of color
J Prosthet Dent
(1973)
J.F. Lasserre et al.
A comparison between a new visual method of color matching by intraoral camera and conventional visual and spectrometric methods
J Dent
(2011)
A. Obregon et al.
A comparative study of the effects of color of the opaque and porcelain surface texture on the ceramo-metal restoration
J Prosthet Dent
(1981)
S.J. Chu et al.
Dental color matching instruments and systems. Review of clinical and research aspects
J Dent
(2010)
A. Sarafianou et al.
Matching repeatability and interdevice agreement of 2 intraoral spectrophotometers
J Prosthet Dent
(2012)
I. Hammad
Intrarater repeatability of shade selection with two shade guides
J Prosthet Dent
(2003)
T.P. van der Burgt et al.
A comparison of new and conventional methods for quantification of tooth color
J Prosthet Dent
(1990)
G.R. Goldstein et al.
Repeatability of a specially designed intraoral colorimeter
J Prosthet Dent
(1993)

Y.K. Lee et al.

Influence of illuminating and viewing aperture size on the color of dental resin composites

Dent Mater

(2004)

H.N. Lim et al.

Spectroradiometric and spectrophotometric translucency of ceramic materials

J Prosthet Dent

(2010)

A.G. Wee et al.

Variation in color between intended matched shade and fabricated shade of dental porcelain

J Prosthet Dent

(2002)

H.N. Lim et al.

Correlations between spectroradiometric and spectrophotometric colors of all ceramic materials

Dent Mater

(2010)

A. Hasegawa et al.

Color and translucency of in vivo natural central incisors

J Prosthet Dent

(2000)

W.M. Johnston

Color measurement in dentistry

J Dent

(2009)

Q. Li et al.

Spectrophotometric comparison of translucent composites and natural enamel

J Dent

(2010)

S.T. Woo et al.

Comparison of translucency between indirect and direct resin composites

J Dent

(2008)

S.J. Kim et al.

Translucency and masking ability of various opaque-shade composite resins

J Dent

(2009)

T. Shiraishi et al.

Optical properties of base dentin ceramics for all-ceramic restorations

Dent Mater

(2011)

F. Wang et al.

Translucency of dental ceramic with different thicknesses

J Prosthet Dent

(2013)

Cited by (27)

Pulse oximetry as a dental pulp test: A scoping review to identify barriers hindering the use of oximeters in clinical practice
2024, Saudi Dental Journal
Although medical pulse oximeters are considered effective for endodontic diagnoses, the method remains uncommon in current dental practice. The aim of the present scoping review was to investigate clinical factors that exert a negative impact on the use of pulse oximeters in dental practice.
This study followed the PRISMA-ScR guidelines and the protocol was prospectively registered in the Open Science Framework (https://doi.org/10.17605/OSF.IO/3GQCE). A comprehensive search of the MEDLINE (via PubMed), Cochrane Library, and Web of Science databases was performed in December 2022 for articles published in English or Spanish. All types of clinical studies were included, except comments, letters to the editor, and abstracts. Two independent investigators analyzed 45 full-text articles. Data extraction included general characteristics, oxygen saturation levels, and limiting factors/barriers to the use of oximeters as pulp testers.
The search of the databases yielded 1,300 records and 38 were included (quantitative data extraction was performed for 35 and three articles were systematic reviews). Publications were highest in number between 2016 and 2017, with an evident reduction occurring after 2021. The oxygen saturation level for sound/vital maxillary anterior teeth was 84.99% (overall mean). The main limiting factors/barriers were i) the difficulty in maintaining the two light-emitting diodes parallel during pulp tests, ii) infrared light diffraction by enamel/dentin/gingiva, and iii) the diversity of patient ages in studies.
This scoping review encountered noteworthy findings associated with the impracticability of using medical pulse oximeters as dental pulp testers. The recent decrease in the frequency of published studies compared to approximately seven years ago may imply a negative trend in the use of the method.
Color alteration with ceramic veneers according to the tooth type and preparation step: A clinical analysis
2022, Journal of Prosthetic Dentistry
Citation Excerpt :
In the present study, instrumental color evaluation was used to compare the variations in ceramic veneers after cementation. Different types of teeth (maxillary central incisors, maxillary lateral incisors, and maxillary canines) have different optical appearances and properties.16,35 No significant interaction for color variables was found between tooth type and the thickness of the ceramic veneers for tooth type or for the interaction between tooth type and time evaluated.
Achieving accurate tooth color is important in esthetic dental treatments; however, clinical studies evaluating how ceramic veneer procedures affect color alterations are lacking.
The purpose of this clinical study was to assess the color alteration during treatment with ceramic veneers and to correlate these changes with the tooth treated and veneer thickness.
Ten patients who underwent esthetic treatment were enrolled as participants. Color analysis with the VITA spectrophotometer was performed at baseline, after tooth preparation, immediately after cementation (Final 1), and after 6 to 12 months of follow-up (Final 2). Data of L∗, a∗, b∗, shade guide unit (SGU), ΔE_ab, ΔE₀₀, and variation in SGU (ΔSGU) were obtained. Thickness of the veneer was also recorded. Each participant was considered as a statistical block, and the mean results for each tooth (maxillary central incisors, lateral incisors, and canines) were presented. Data were evaluated by the mixed model for repeated measures and Tukey-Kramer post hoc test (L∗, a∗, b∗), generalized linear models (thickness, ΔE_ab, ΔE₀₀, SGU), Friedman test (ΔSGU), and the Pearson test was used to correlate veneer thickness and color change (ΔE_ab, ΔE₀₀, ΔSGU) (α=.05).
Among the teeth treated, no differences were found in ceramic thicknesses. The mean thickness was 1.03 mm for central incisors, 0.96 for lateral incisors, and 0.89 for canines. The b∗ values increased significantly after preparation and decreased after cementation (P<.001). For ΔE_ab, ΔE₀₀, and ΔSGU, there was no statistically significant difference between the types of tooth at each respective time of analysis (P>.05). Regardless of the tooth, a decrease in the SGU score was detected after cementation (P=.015). After tooth preparation, there was significant correlation (P<.05) between ceramic thickness and ΔSGU (r=0.36).
Treatment with ceramic veneers resulted in color change, mainly with respect to the b∗ axis (yellow), producing objective differences in the ΔE analysis. Although ceramic thickness correlated with the VITA scale change (ΔSGU) after tooth wear or preparation, ceramic thickness did not differ among tooth types and did not correlate with changes in color parameters after cementation. (P>.05).
Color stability of ceramic laminate veneers cemented with light-polymerizing and dual-polymerizing luting agent: A split-mouth randomized clinical trial
2017, Journal of Prosthetic Dentistry
Citation Excerpt :
A standard clinical spectrophotometer was used. Color measurements may be subject to edge loss when such small-aperture devices are used, which is influenced by curved dental surfaces and translucent ceramic measured.34 In addition, our findings might not extrapolate to the anterior teeth as they would presumably be more exposed to environmental ultraviolet light, which can induce the oxidation of tertiary amines.16
The color stability of luting agents influences the esthetics of ceramic laminate veneers. Clinical studies that have evaluated the color changes of veneers cemented to enamel with light- and dual-polymerizing resin cement are lacking.
The purpose of this split-mouth randomized clinical trial was to evaluate the color change and marginal discoloration of dual- and light-polymerizing cement used for cementation of ceramic laminate veneers.
In 10 participants, 0.3-mm-thick ceramic laminate veneers were cemented on the buccal surface of the second premolars without tooth preparation. A randomized application of light-polymerized cement was used on one side and a dual-polymerized cement on the contralateral side. The operator and participants were blinded to the activation mode. Color was evaluated by a blinded evaluator with a spectrophotometer at 24 hours and at 2, 6, 12, and 24 months after cementation. The CIELab (ΔE*_ab) and CIEDE2000 (ΔE*₀₀) formulas were used to quantify color alteration, and Δa*, Δb*, and ΔL* were calculated between the first and subsequent measurements. US Public Health Service guidelines were used to evaluate the marginal discoloration.
Wilcoxon tests did not show a statistical difference in ΔE*_ab and ΔE*₀₀ between the groups (P>.05). At 24 months, the median ΔE*_ab was 2.31 (interquartile ranges [IQR]: 3.34) for the light-polymerizing mode and 1.57 (IQR: 0.41) for the dual-polymerizing mode, while the median ΔE*₀₀ was 1.65 for the light-polymerizing mode (IQR: 2.34) and 1.18 for the dual-polymerizing mode (IQR: 0.25). The thresholds for clinically acceptable color changes ΔE*_ab>3.46 and ΔE*₀₀>2.25 were found for both curing modes. Marginal discoloration was observed from the 2-year assessment.
The color stability of ceramic laminate veneers was similar for both of the polymerizing modes for all evaluated periods. Marginal discoloration increased over a 2-year period for both the light- and the dual-polymerizing modes.
Optical properties of pre-colored dental monolithic zirconia ceramics
2016, Journal of Dentistry
Citation Excerpt :
Unlike those studies, Pittayachawan et al. [21] and Sedda et al. [1] reported that coloring procedures did not have any adverse effects on the flexural strength of zirconia ceramics. Several studies [22–24] investigated the optical properties of natural dentitions and therefore, the reproduction of color and translucency of natural teeth would be an ultimate goal for esthetic dental restorations. Recent study [8] evaluated the effect of coloring on the optical properties of monolithic zirconia ceramics.
The purposes of this study were to evaluate the optical properties of recently marketed pre-colored monolithic zirconia ceramics and to compare with those of veneered zirconia and lithium disilicate glass ceramics.
Various shades of pre-colored monolithic zirconia, veneered zirconia, and lithium disilicate glass ceramic specimens were tested (17.0 × 17.0 × 1.5 mm, n = 5). CIELab color coordinates were obtained against white, black, and grey backgrounds with a spectrophotometer. Color differences of the specimen pairs were calculated by using the CIEDE2000 ( $Δ E_{00}$ ) formula. The translucency parameter (TP) was derived from $Δ E_{00}$ of the specimen against a white and a black background. X-ray diffraction was used to determine the crystalline phases of monolithic zirconia specimens. Data were analyzed with 1-way ANOVA, Scheffé post hoc, and Pearson correlation testing (α = 0.05).
For different shades of the same ceramic brand, there were significant differences in L*, a*, b*, and TP values in most ceramic brands. With the same nominal shade (A2), statistically significant differences were observed in L*, a*, b*, and TP values among different ceramic brands and systems (P < 0.001). The color differences between pre-colored monolithic zirconia and veneered zirconia or lithium disilicate glass ceramics of the corresponding nominal shades ranged beyond the acceptability threshold.
Due to the high L* values and low a* and b* values, pre-colored monolithic zirconia ceramics can be used with additional staining to match neighboring restorations or natural teeth.
Due to their high value and low chroma, unacceptable color mismatch with adjacent ceramic restorations might be expected.
Effect of High-Speed Sintering on the Optical Properties, Microstructure, and Phase Distribution of Multilayered Zirconia Stabilized with 5 mol% Yttria
2023, Materials
The Clinical Potential of 3D-Printed Crowns Reinforced with Zirconia and Glass Silica Microfillers
2023, Journal of Functional Biomaterials

View all citing articles on Scopus

: Supported by European Social Fund Human Resources Development Operational Program 2007-2013 project no. POSDRU/159/1.5/S/138776.

View full text

Research and EducationDentin translucency and color evaluation in human incisors, canines, and molars

Abstract

Statement of problem

Purpose

Material and methods

Results

Conclusions

Section snippets

Material and Methods

Results

Discussion

Conclusions

Acknowledgments

J Prosthet Dent

J Prosthet Dent

J Prosthet Dent

J Dent

J Prosthet Dent

J Dent

J Prosthet Dent

J Prosthet Dent

J Prosthet Dent

J Prosthet Dent

Dent Mater

J Prosthet Dent

J Prosthet Dent

Dent Mater

J Prosthet Dent

J Dent

J Dent

J Dent

J Dent

Dent Mater

J Prosthet Dent

Research and Education
Dentin translucency and color evaluation in human incisors, canines, and molars