Accuracy of an intraoral digital scanner in tooth color determination

Abstract Introduction This study evaluated the reproducibility of electronic color determination system evaluations of the marginal gingiva, which could be important for adhesive cervical fillings or prosthetic restorations that imitate the gingiva. Material and methods In 50 subjects, the L*, a*, and b* color coordinates were evaluated five times at a point in the marginal area of a central incisor using different electronic color determination systems: (SP) Shadepilot, (ES) Easyshade, (CE) Crystaleye, and (SV) X-Rite. The mean color difference (ΔE) and its standard deviation between the five measurements from each participant were calculated separately for each device. Further ICC for interdevice reliability was determined. Results The L*, a*, and b* color coordinates and ΔE values differed significantly among the systems (p < 0.001). Within each patient and measurement system, ΔE ranged from 1.4 to 3.2 (SD 1.1–2.5), L* from 2.6 to 5.7 (SD 2.6–5.7), a* from 11.9 to 21.3 (SD 3.6–3.9), and b* from 15.1 to 28.9 (SD 1.7–4.3). Interdevice reliability ranged between 0.675 and 0.807. Conclusions Color determination of the marginal gingiva using the electronic tooth color determination systems tested herein showed limited reproducibility. The results obtained with the different measurement systems differed enormously. Clinical relevance These results show that the electronic color measurement devices tested allow no high reproducible determination of color coordinates of the marginal gingiva.

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Accuracy of an intraoral scanner in tooth color determination: Clinical evaluation

Clinical Oral Implants Research ◽

10.1111/clr.300_13509 ◽

2019 ◽

Vol 30 (S19) ◽

pp. 344-344

Author(s):

Julius Dirsė ◽

Vygandas Rutkunas ◽

Vytautas Bilius ◽

Agne Gedrimiene

Keyword(s):

Clinical Evaluation ◽

Intraoral Scanner ◽

Tooth Color ◽

Color Determination

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A Digital Shade-Matching Device for Dental Color Determination Using the Support Vector Machine Algorithm

Sensors ◽

10.3390/s18093051 ◽

2018 ◽

Vol 18 (9) ◽

pp. 3051 ◽

Cited By ~ 3

Author(s):

Minah Kim ◽

Byungyeon Kim ◽

Byungjun Park ◽

Minsuk Lee ◽

Youngjae Won ◽

...

Keyword(s):

Support Vector Machine ◽

Classification Performance ◽

Support Vector ◽

Robot Arm ◽

K Nearest Neighbors ◽

Tooth Color ◽

Color Determination ◽

Svm Algorithm ◽

Shade Matching ◽

Optimum Solution

In this study, we developed a digital shade-matching device for dental color determination using the support vector machine (SVM) algorithm. Shade-matching was performed using shade tabs. For the hardware, the typically used intraoral camera was modified to apply the cross-polarization scheme and block the light from outside, which can lead to shade-matching errors. For reliable experiments, a precise robot arm with ±0.1 mm position repeatability and a specially designed jig to fix the position of the VITA 3D-master (3D) shade tabs were used. For consistent color performance, color calibration was performed with five standard colors having color values as the mean color values of the five shade tabs of the 3D. By using the SVM algorithm, hyperplanes and support vectors for 3D shade tabs were obtained with a database organized using five developed devices. Subsequently, shade matching was performed by measuring 3D shade tabs, as opposed to real teeth, with three additional devices. On average, more than 90% matching accuracy and a less than 1% failure rate were achieved with all devices for 10 measurements. In addition, we compared the classification algorithm with other classification algorithms, such as logistic regression, random forest, and k-nearest neighbors, using the leave-pair-out cross-validation method to verify the classification performance of the SVM algorithm. Our proposed scheme can be an optimum solution for the quantitative measurement of tooth color with high accuracy.

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The Influence of Dental Occlusion on Spectrophotometric Tooth Color Determinations

The Open Dentistry Journal ◽

10.2174/1874210602014010247 ◽

2020 ◽

Vol 14 (1) ◽

pp. 247-254 ◽

Cited By ~ 1

Author(s):

Marta Mazur ◽

Stephen Westland ◽

Maciej Jedliński ◽

Antonello Maruotti ◽

Gianna Maria Nardi ◽

...

Keyword(s):

The United States ◽

Dental Students ◽

High Rate ◽

Dental Occlusion ◽

Color Matching ◽

Significant Treatment ◽

Tooth Color ◽

Color Determination ◽

Tooth Width ◽

Dental Practitioners

Background: Shade matching is a significant treatment step and a challenge for the clinical team with potentially high costs for color correction. Currently, in the United States, the majority of private dental practitioners use visual color matching, but a recent study has reported a high rate of mistakes of subjective color determination among graduate dentists. Objective: The aim of this retrospective study is to analyze whether a change in the oral background due to dental occlusion can influence tooth color determination. Methods: Volunteer dental students underwent spectrophotometric color assessment using the SpectroShade device. Two measurements were carried out (with the individuals’ occlusion closed and with the occlusion open) on 43 upper central and 58 lateral incisors. Association between colorimetric variables L*, a*, b* and ΔE00 and tooth width, length and tobacco usage were examined. Results: Slight changes in the CIELAB values between closed and open occlusions were found for both the gingival and the central sections as for the overall tooth area, with mean ΔL*=-1.24, Δa*=-1.77, Δb*=-1.42 and ΔE00=1,84. A larger difference was detected in the incisal area, with mean ΔL*=-2.99, Δa*=-1.76, Δb*=-2.83 and ΔE00=3.65. Conclusion: In conclusion, our study showed that dental occlusion does not play a significant role in tooth color matching determinations, even though attention to avoid overbite due to a maximum intercuspation should be made.

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Comparative characteristics of conventional visual methods and instrumental digital methods for tooth color determination

Российский стоматологический журнал ◽

10.17816/1728-2802-2020-24-5-344-354 ◽

2020 ◽

Vol 24 (5) ◽

pp. 344-354

Author(s):

M. M. Hasasna ◽

Andrey V. Akulovich

Keyword(s):

Quality Criteria ◽

Color Measurement ◽

Target Color ◽

Visual Methods ◽

Tooth Color ◽

Color Determination ◽

Important Quality ◽

Shade Matching ◽

Digital Methods ◽

Instrumental Methods

Shade matching is a challenging step and the major objective in esthetic and restorative dentistry. On many occasions, the production of the accurate target color will not be achieved due to errors in the registration of the target color, or errors in composing the appropriate color of the restoration in the dental laboratory. Thus, the accurate and correct shade matching of tooth and restoration is one of the most important quality criteria for the patient and the key to successful results for the dentist. Conclusion: Spectrophotometers, colorimeters, intraoral scanners, and imaging systems are useful and relevant tools for tooth color measurement and analysis, and for the quality control of color reproduction. The combination of visual and instrumental methods of tooth color determination will complement each other, leading toward predictable esthetic results.

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Laser Influence on Dental Sensitivity Compared to Other Light Sources Used During In-office Dental Bleaching: Systematic Review and Meta-analysis

Operative Dentistry ◽

10.2341/19-064-l ◽

2020 ◽

Vol 45 (6) ◽

pp. 589-597

Author(s):

BGS Casado ◽

EP Pellizzer ◽

JR Souto Maior ◽

CAA Lemos ◽

BCE Vasconcelos ◽

...

Keyword(s):

Randomized Clinical Trials ◽

Color Change ◽

Meta Analysis ◽

Present Review ◽

Cochrane Library ◽

Light Sources ◽

Eligibility Criteria ◽

Tooth Color ◽

Significant Difference ◽

Meta Analyses

Clinical Relevance The use of laser light during bleaching will not reduce the incidence or severity of sensitivity and will not increase the degree of color change compared with nonlaser light sources. SUMMARY Objective: To evaluate whether the use of laser during in-office bleaching promotes a reduction in dental sensitivity after bleaching compared with other light sources. Methods: The present review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and is registered with PROSPERO (CDR42018096591). Searches were conducted in the PubMed/Medline, Web of Science, and Cochrane Library databases for relevant articles published up to August 2018. Only randomized clinical trials among adults that compared the use of laser during in-office whitening and other light sources were considered eligible. Results: After analysis of the texts retrieved during the database search, six articles met the eligibility criteria and were selected for the present review. For the outcome dental sensitivity, no significant difference was found favoring any type of light either for intensity (mean difference [MD]: −1.60; confidence interval [CI]: −3.42 to 0.22; p=0.09) or incidence (MD: 1.00; CI: 0.755 to 1.33; p=1.00). Regarding change in tooth color, no significant differences were found between the use of the laser and other light sources (MD: −2.22; CI: −6.36 to 1.93; p=0.29). Conclusions: Within the limitations of the present study, laser exerts no influence on tooth sensitivity compared with other light sources when used during in-office bleaching. The included studies demonstrated that laser use during in-office bleaching may have no influence on tooth color change.

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The Whitening Effect and Histological Safety of Nonthermal Atmospheric Plasma Inducing Tooth Bleaching

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18094714 ◽

2021 ◽

Vol 18 (9) ◽

pp. 4714

Author(s):

Seoul-Hee Nam ◽

Byul Bo Ra Choi ◽

Gyoo-Cheon Kim

Keyword(s):

Alternative Energy ◽

Soft Tissues ◽

Inflammatory Responses ◽

Color Change ◽

Atmospheric Pressure Plasma ◽

Atmospheric Plasma ◽

Tooth Bleaching ◽

Histological Evaluation ◽

Light Sources ◽

Tooth Color

Various light sources have been applied to enhance the bleaching effect. This study was to identify the histological evaluation in oral soft tissues, as well as tooth color change after tooth bleaching by nonthermal atmospheric pressure plasma (NAPP). Nine New Zealand adult female rabbits were randomly divided into three groups (n = 3): group 1 received no treatment; group 2 was treated with NAPP and 15% carbamide peroxide (CP), which contains 5.4% H2O2, and group 3 was treated with 15% CP without NAPP. Color change (ΔE) was measured using the Shade Eye NCC colorimeter. Animals were euthanized one day later to analyze the histological responses occurring in oral soft tissues, including pulp, gingiva, tongue, buccal mucosa, and hard and soft palates. Changes in all samples were analyzed by hematoxylin and eosin staining and Masson’s trichrome. Teeth treated with plasma showed higher ΔE than that obtained with bleaching agents alone. Overall, the histological characteristics observed no appreciable changes. The combinational treatment of plasma had not indicated inflammatory responses as well as thermal damages. NAPP did not cause histological damage in oral soft tissues during tooth bleaching. We suggest that NAPP could be a novel alternative energy source to conventional light sources for tooth bleaching.

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Tooth discoloration induced by apical plugs with hydraulic calcium silicate-based cements in teeth with open apices—a 2-year in vitro study

Clinical Oral Investigations ◽

10.1007/s00784-021-04009-0 ◽

2021 ◽

Author(s):

Ralf Krug ◽

C. Ortmann ◽

S. Reich ◽

B. Hahn ◽

G. Krastl ◽

...

Keyword(s):

Calcium Silicate ◽

In Vitro Study ◽

Color Difference ◽

Blood Contamination ◽

Tooth Color ◽

Color Changes ◽

Gutta Percha ◽

Tooth Discoloration ◽

Post Hoc

Abstract Objectives To assess tooth discoloration induced by different hydraulic calcium silicate-based cements (HCSCs), including effects of blood and placement method. Materials and methods Eighty bovine teeth cut to a length of 18 mm (crown 8 mm, root 10 mm) were randomly assigned to 10 groups (n = 8), receiving orthograde apical plug treatment (APT). Apical plugs were 4 mm in length and made of ProRoot MTA (Dentsply), Medcem MTA (Medcem), TotalFill BC RRM Fast Set Putty (Brasseler), or Medcem Medical Portland Cement (Medcem) plus bismuth oxide (Bi2O3) with and without bovine blood. Further, orthograde (with or without preoperative adhesive coronal dentin sealing) and retrograde APT were compared. Teeth were obturated with gutta-percha and sealer, sealed with composite and stored in distilled water. Tooth color was measured on apical plug, gutta-percha/sealer, and crown surface before treatment versus 24 h, 1, 3, 6, 12, and 24 months after treatment by spectrophotometry. Color difference (ΔE) values were calculated and analyzed by Shapiro–Wilk test, ANOVA with post hoc tests, Friedman test, t test, and post hoc tests with Bonferroni correction (α = .05). Results Tooth discoloration occurred in all groups with no significant differences between HCSCs (p > .05). After 24 months, color changes were prominent on roots but insignificant on crowns. Blood contamination induced a significantly decreased luminescence (p < .05). Blood had a stronger impact on tooth color than Bi2O3. No relevant effects of retrograde placement (p > .05) or preoperative dentin sealing (p > .05) were detected. Conclusions Apical plugs of the tested HCSCs cause discoloration of bovine roots, but not discoloration of bovine tooth crowns within a 24-month period. Clinical relevance APT should be performed carefully while avoiding direct contact with the coronal dentin, and in that case no aesthetic impairments occur.

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Preparation and Performance Evaluation of Duotone 3D-Printed Polyetheretherketone as Oral Prosthetic Materials: A Proof-of-Concept Study

Polymers ◽

10.3390/polym13121949 ◽

2021 ◽

Vol 13 (12) ◽

pp. 1949

Author(s):

Ling Ding ◽

Wei Lu ◽

Jiaqi Zhang ◽

Chuncheng Yang ◽

Guofeng Wu

Keyword(s):

Titanium Dioxide ◽

Performance Evaluation ◽

Mechanical Performance ◽

Mechanical Tests ◽

Flexural Properties ◽

Proof Of Concept ◽

Tooth Color ◽

Dental Application ◽

3D Printed ◽

And Performance

Literature has reported the successful use of 3D printed polyetheretherketone (PEEK) to fabricate human body implants and oral prostheses. However, the current 3D printed PEEK (brown color) cannot mimic the vivid color of oral tissues and thus cannot meet the esthetical need for dental application. Therefore, titanium dioxide (TiO2) and ferric oxide (Fe2O3) were incorporated into PEEK to prepare a series of tooth-color and gingival-color PEEK composites in this study. Through color measurements and mechanical tests, the color value and mechanical performance of the 3D printed PEEK composites were evaluated. In addition, duotone PEEK specimens were printed by a double nozzle with an interface between tooth-color and gingival-color parts. The mechanical performance of duotone PEEK with two different interfaces (horizontal and vertical) was investigated. With the addition of TiO2 and Fe2O3, the colors of 3D printed PEEK composites become closer to that of dental shade guides. 3D printed PEEK composites generally demonstrated superior tensile and flexural properties and hence have great potential in the dental application. In addition, duotone 3D printed PEEK with a horizontal interfacial orientation presented better mechanical performance than that with a vertical one.

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