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Purpose: Uses for artificial intelligence (AI) are being explored in contemporary dentistry, but artificial intelligence in dental shade‐matching has not been systematically reviewed and evaluated. The purpose of this systematic review was to evaluate the accuracy of artificial intelligence in predicting dental shades in restorative dentistry. Methods: A systematic electronic search was performed with the databases MEDLINE (PubMed), Scopus, Cochrane Library, and Google Scholar. A manual search was also conducted. All titles and abstracts were subject to the inclusion criteria of observational, interventional studies, and studies published in the English language. Narrative reviews, systematic reviews, case reports, case series, letters to the editor, commentaries, studies that were not AI‐based, studies that were not related to dentistry, and studies that were related to other disciplines in dentistry, other than restorative dentistry (prosthodontics and endodontics) were excluded. Two investigators independently evaluated the quality assessment of the studies by applying the Joanna Briggs Institute Critical Appraisal Checklist for Quasi‐Experimental Studies (non‐randomized experimental studies). A third investigator was consulted to resolve the lack of consensus. Results: Fifty‐three articles were initially found from all the searches combined from articles published from 2008 till March 2023. A total of 15 articles met the inclusion criteria and were included in the systematic review. AI algorithms for shade‐matching include fuzzy logic, a genetic algorithm with back‐propagation neural network, back‐propagation neural networks, convolutional neural networks, artificial neural networks, support vector machine algorithms, K‐nearest neighbor with decision tree and random forest, deep learning for detection of dental prostheses based on object‐detection applications, You Only Look Once‐YOLO. Moment invariant was used for feature extraction. XG (Xtreme Gradient) Boost was used in one study as a gradient‐boosting machine learning algorithm. The highest accuracy in the prediction of dental shades was the decision tree regression model for leucite‐based dental ceramics of 99.7% followed by the fuzzy decision of 99.62%, and support vector machine using cross‐validation of 97%. Conclusions: Lighting conditions, shade‐matching devices and color space models, and the type of AI algorithm influence the accuracy of the prediction of dental shades. Knowledge‐based systems and neural networks have shown better accuracy in predicting dental shades. [ABSTRACT FROM AUTHOR]

Shade determination is a crucial part of making aesthetic restorations and is still carried out visually in most cases. The most commonly used VITA Classical (VC) shade guide is made of acrylic. Due to everyday usage and several disinfection cycles, these shade tabs go through discoloration. Our study aims to investigate the extent of discoloration of the VC shade guides, which are regularly used daily at the Department of Prosthodontics at Semmelweis University. A1, A2, A3, C2, C3 and D2 shades were evaluated which are the most common colors of natural dentition. 9 shade tabs of each color (54 in total) were compared to a corresponding new reference shade tabs both visually and digitally. For the digital color comparison, the VITA Easyshade V spectrophotometer was used to extract the L*a*b values for color comparison, every shade tab (the sample shade tabs (54 in total) and the reference shade tabs) were measured 3 times. ΔE values (color difference) were calculated from the measured L*a*b values with the help of the CIEDE 2000 formula. 70.4% of the tested shade guides showed a color difference (above 0.8 ΔE). Unacceptable color differences (above 1.8 ΔE) were found in 32.4% of the tested shade guides. Only 29,6% of the shade guides were under the perceptibility threshold. During the visual comparison, the examiners found color differences in the case of 38 out of 54 shade guides. Acrylic tooth shade guides go through discoloration over time which can lead to clinical failures. The shade guides used on a daily basis in the dental office need to be verified regularly.

Copyright of Fogorvosi Szemle is the property of Hungarian Dental Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: The objective of this study was to investigate the effects of liquid coloring in different dipping times and finishing procedures on color difference of precolored and liquid-colored monolithic zirconia ceramics. Materials and Methods: 240 zirconia specimens were divided according to shades of coloring liquid (A1, A2, and A3), dipping time (3, 5, and 7 minutes), and surface finishing procedures (glaze and mechanical polishing) (n=10). CIE L*, a*, and b* values of the specimens were measured and color differences (ΔE) were calculated. The data were analyzed with three-way analysis of variance (ANOVA) and Tukey HSD test (α=.05). Results: Coloring with liquids, dipping time, and finishing procedures significantly affected the CIE L*, a*, and b* values (P

Copyright of Acta Odontologica Turcica is the property of Acta Odontologica Turcica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The optical qualities of cutting-edge aesthetic dental ceramics are crucial for great aesthetics and may be impacted by various bleaching methods. The objectives of this study were to evaluate how home bleaching affected the translucency parameter (TP), contrast ratio (CR), total color difference (ΔE), and surface roughness (Ra) of various aesthetic dental ceramics, including innovative ultra-translucent zirconia. The three varieties of ceramics that were tested—IPS e.max-Press (IPS); classic zirconia with feldspathic layering (LZr); and translucent zirconia (TZr)—were each represented by seven samples. The samples were bleached at home using 15% carbamide peroxide for six hours a day for seven days. Each specimen's pre- and post-bleaching CIE L*a*b* values were measured using a spectrophotometer, and the TP, CR, and ΔE were determined. Ra values were measured via 3D profilometry. In comparison to the pre-stage results, statistical analysis showed a significant decrease in TP and increase in CR for LZr and TZr in the post-stage (p < 0.05), but not for IPS (p = 0.398). The results also showed substantial variations in ΔE for the three ceramics (p = 0.020). Ra readings during the post-stage were noticeably greater than those at the pre-stage (p = 0.018). Home bleaching had an impact on the optical characteristics and surface texture of the dental ceramics. Additionally, IPS had greater color stability than LZr and TZr. [ABSTRACT FROM AUTHOR]

The effect of a novel nano-ceramic coating (TiO2) using an atomic layer deposition (ALD) technique on the surface of polymethyl methacrylate (PMMA) material was investigated. The patients' and clinicians' perception and acceptance of the PMMA color with TiO2 coating were also examined. In vitro color measurement was performed on thirty specimens (light, original, and dark pink) before and after TiO2 coating. Patients' and clinicians' perception and acceptance of color changes on PMMA were measured and compared. Descriptive and analytic statistics were analyzed (a = 0.05). TiO2 films were successfully deposited on the PMMA specimen by the ALD technique. Color changes after TiO2 coating were observed on all three PMMA shades, significantly higher than the established 50:50% perceptibility threshold, but below the established 50:50% acceptability threshold. The percentage of patients that perceived a color difference after TiO2 coating were 83.3%, 63.9%, and 77.8% for light, original, and dark pink, respectively. The percentages of clinicians that were satisfied with the color difference were 96.4%, 80%, and 69.2% for light, original, and dark pink, respectively. Color changes after TiO2 coating were observed, but below the acceptable threshold. The clinical survey demonstrated that a color difference was perceived but was clinically acceptable. In general, laypeople have lower perception and higher acceptance of changes in PMMA color than clinicians. [ABSTRACT FROM AUTHOR]

Objective: This study evaluated the influence of tooth shade, resin-based luting agent shade values, and ceramic thickness on the optical properties of CLVs., Materials and Methods: The study involved 16 participants who received 95 CLVs. CIE L*, a*, b* color coordinates were assessed with a clinical spectrophotometer. Variables considered were: luting agent value in three levels (high, medium, low); tooth shade before and after preparation in two levels (lighter and darker shades); and CLV thickness in two levels (< 1 mm, ≥ 1 mm). The color difference (ΔE 00 ) was analyzed under four scenarios, utilizing statistical methods suitable for non-normal distributions., Results: Ninety-five CLVs (n = 95) were analyzed, ceramic thicknesses mean (SD) values were 0.70 (± 0.15) for < 1 mm group and 1.19 (0.20) for ≥ 1 mm group. ΔE 00 values ranging from 2.93 to 9.72, all exceeding the thresholds of perceptibility and acceptability. Significant variations were observed in optical outcomes based on the clinical variables studied, particularly showing that high-value luting agents are more effective over darker substrates (p = 0.043). Thicker ceramics significantly improved masking capabilities, demonstrating their critical role in esthetic treatments (p = 0.024). No significant differences were found regarding the tooth shade after preparation (p = 0.215)., Conclusion: The study confirmed that luting agent shade values and ceramic thickness, critically influence the final optical properties of CLVs. High-value luting agents and thicker ceramics effectively achieved acceptable color differences, especially over darker tooth substrates. These findings underscore the importance of carefully selecting materials and techniques to optimize optical outcomes in CLV restorations., Clinical Significance: Luting agent's value and ceramic thickness plays a critical role in achieving natural-looking ceramic laminate veneers, especially on darker tooth substrates. These factors significantly impact the final color matching and esthetic outcome., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The minimally invasive endodontic access is not directly associated with tooth discoloration in the presence of bioceramic or epoxy resin-based root canal sealers. This study aimed to evaluate the influence of minimally invasive access and endodontic sealer composition on the color stability of endodontically-treated teeth, the restorative material adaptation, and the presence of remaining filling material in the pulp chamber. Endodontic access surgery was performed in maxillary central incisors, either through conservative or minimally invasive approaches, and the root was filled with AH Plus or Bio-C Sealer. The crown color was measured with a spectrophotometer at baseline and after root obturation, restoration, and specimen storage for one year in an oven. The occurrence of voids in the restoration and the remaining filling material was analyzed using micro-CT scans. The Yellowness Index (YI) and color changes (∆E00) were calculated after each color measurement. Data of micro-CT were submitted to 2-way ANOVA, and YI and ∆E00 were analyzed with repeated-measures ANOVA. Pair-wise comparisons were performed with Tukey's test (α = 0.05). The experimental conditions had no effect on the presence of the remaining material. The minimally invasive access associated with Bio-C Sealer resulted in more voids between the restoration and the remaining filling material. Only the evaluation time affected YI and ∆E00 values. Specimens became more yellow after filling and storage in the oven (the highest ∆E00 values). The present study showed that sealer and minimally invasive cavities are not associated with crown color stability following endodontic treatment.

Objectives: The aim of the present prospective study was to evaluate the colour stability of 3D-printed non-invasive restorations after 24 months in vivo., Methods: The study included 29 patients, who received 3D-printed restorations made of a computer-aided design (CAD) / computer aided-manufacturing (CAM) hybrid material (n = 354). Restoration colour of 190 restorations was measured using a spectrophotometer. By applying the CIELAB system, *L (lightness), a* (red-green) and b* (blue-yellow) values were recorded. An evaluation of the colour differences (ΔE) after 6, 12 and 24 months was conducted., Results: Analysis of colour differences of 3D-printed restorations showed continuous discolouration of the restorations. After one year 34 % and after two years 18 % of the restorations were rated alpha or bravo, indicating no or hardly visible colour change. After two years, 54 % of the evaluated restorations yielded a colour difference with ΔE > 6.8 (delta). More than 82 % of the evaluated restorations showed values between ΔE 3.8 - 6.8 (charlie) and ΔE ˃ 6.8 (delta) after two years., Conclusions: 3D-printed non-invasive restorations showed an overall reduced colour stability after 24 months in vivo., Clinical Significance: The present study provides first clinical data regarding 3D-printed restorations. These restorations are recommended for a wearing time of about 6 months., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Elisabeth Prause reports equipment, drugs, or supplies was provided by BEGO. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Statement of Problem: Little is known about the effect of illuminant metamerism between natural teeth and zirconia restorations, despite their increasing clinical popularity., Purpose: The purpose of this in vitro study was to compare illuminant metamerism between pairs of natural teeth and layered zirconia restorations and pairs of natural teeth and monolithic zirconia restorations under 10 different illuminants and analyze their metameric potential., Material and Methods: Spectral reflectance factors were obtained from 10 pairs of extracted natural teeth and layered zirconia restorations and 28 pairs of extracted natural teeth and monolithic multilayer zirconia restorations. Each pair showed a color match that was within the visual threshold for clinical acceptability (CIEDE2000≤1.8). A special index of metamerism for the change of illuminant (M ilm ) was calculated from the CIEDE2000 color difference equation. Descriptive statistics and the one-sample t test were used to analyze the results for the M ilm and for both groups of layered and monolithic zirconia restorations (α=.05)., Results: Layered zirconia restorations reached a mean ±standard deviation value for M ilm =0.3 ±0.2 and M ilm =0.5 ±0.4 for monolithic zirconia restorations (P<.01)., Conclusions: The effect of illuminant metamerism between natural teeth and zirconia crowns was weak and generally within the clinical acceptability limit., (Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Objective: This study assessed the effect of the anodization of titanium abutments on the color parameters and color difference of lithium disilicate (LDS) all-ceramic crowns., Materials and Methods: In this study, 19 straight abutments were divided into two groups: anodized (n = 9) and non-anodized control (n = 9), with one hybrid zirconia abutment as a reference. Anodization was achieved by applying 63 V energy using seven 9 V flat batteries in series, with an electrolyte solution comprising 1 g trisodium phosphate in 250 mL distilled water for 5 s, resulting in a gold-yellow color. Abutments were then scanned, and full-contour monolithic IPS e.max maxillary central incisor crowns were fabricated with 2 mm thickness and glazed. Reflectance was measured using a spectroradiometer, and color coordinates (L*, a*, b*, h*, and C*) were calculated using CS-10W software. Color differences of the crowns in both groups were quantified using the CIEDE2000 (ΔE 00 ) color difference formula and analyzed by t-test (α = 0.05) compared to the standard sample., Results: The L*, a*, b*, and c* parameters in anodized abutments were significantly higher than those in non-anodized abutments, while the h* parameter in anodized abutments was significantly lower than that in non-anodized abutments (p < 0.001 for all). There was a significant difference in ΔE 00 of the two groups (p = 0.043)., Conclusion: Anodization of titanium abutments improved the color parameters of LDS all-ceramic crowns and significantly decreased their ΔE compared with non-anodized abutments., (© 2024 The Author(s). Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.)

Statement of Problem: The comparative accuracy of different color-matching methods for maxillofacial prostheses is lacking., Purpose: This clinical study aimed to compare prosthesis color matching using the conventional trial and error method with that using the maxillofacial spectrophotometer method., Material and Methods: Fifty-four Indian participants were enrolled based on skin color and divided into Light, Medium, and Dark groups (n=18). Silicone specimens of different thicknesses were fabricated using both the conventional trial and error and maxillofacial spectrophotometer coloration methods for all participants. The color match of the specimens with natural skin was assessed subjectively and objectively using expert consensus and fiber optic spectroscopy with the CIELab color difference formula, respectively. Statistical analyses included the Shapiro-Wilk and independent sample t tests (α=.05)., Results: The mean ΔL* (white-black axis) value for the Skin-Conventional color match difference was significantly lower and positive compared with the Skin-Spectrophotometer match (P=.090) for the sample. The mean Δb* (yellow-blue axis) value for the Skin-Conventional color difference was significantly positive compared with the Skin-Spectrophotometer match (P=.020). The mean ΔE* (color difference) for the Skin-Conventional color match was significantly lower than the Skin-Spectrophotometer value (P=.034). Expert opinion as assessed with a visual analog scale found color matching using the conventional method (7.12) to be significantly better than with the spectrophotometer (6.30). A qualitative analysis of expert opinion revealed that conventional color matching should have been less red (34.3%) and that spectrophotometer matching should have been less yellow (30.1%)., Conclusions: Across different thicknesses of silicone and Indian skin shades, color matching was significantly better for the conventional versus the maxillofacial spectrophotometer method, both objectively and subjectively. The spectrophotometer match was significantly yellower and lighter than natural skin., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Objectives: This multicenter study aimed to evaluate visual-instrumental agreement of six color measurement devices and optimize three color difference equations using a dataset of visual color differences (∆V) from expert observers., Methods: A total of 154 expert observers from 16 sites across 5 countries participated, providing visual scaling on 26 sample pairs of artificial teeth using magnitude estimation. Three color difference equations (ΔE* ab , ∆E 00 , and CAM16-UCS) were tested. Optimization of all three equations was performed using device-specific weights, and the standardized residual sum of squares (STRESS) index was used to evaluate visual-instrumental agreement., Results: The ΔE* ab formula exhibited STRESS values from 18 to 40, with visual-instrumental agreement between 60 % and 82 %. The ∆E 00 formula showed STRESS values from 26 to 32, representing visual-instrumental agreement of 68 % to 74 %. CAM16-UCS demonstrated STRESS values from 32 - 39, with visual-instrumental agreement between 61-68 %. Following optimization, STRESS values decreased for all three formulas, with ΔE ' demonstrating average visual-instrumental agreement of 79 % and ∆E 00 of 78 %. CAM16-UCS showed average visual-instrumental agreement of 76 % post optimization., Significance: Optimization of color difference equations notably improved visual-instrumental agreement, overshadowing device performance. The optimzed ΔE ' formula demonstrated the best overall performance combining computational simplicty with outstanding visual-instrumental agreement., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to design and assess composite resin composition for patient-specific esthetic color-graded temporary veneer., Methods: Various compositions of composite structures (assorted by Ba 2 SiO 4 filler, TiO 2 pigment, and photoinitiator) were prepared via additive manufacturing with 3 s UV exposure (405 nm, 10 W/cm 2 ) per 50 µm thick layer followed by 20 min post-curing treatment after fabrication. The effect of each component on the generated color shades was observed and compared to the commonly used VITA shade guide. The coloration was explored by staining aging treatment under dry, wet, artificial saliva environments, coffee, and cola. The mechanical properties were also evaluated. Color measurement and comparison were done using a colorimeter (lightness (L*), green-red color (a*), and blue-yellow color (b*)), and the changes were calculated by CIEDE2000 (ΔE 00 ), translucency parameter (TP) and whiteness index (WI D ). The composition color analysis results were then applied to produce a color-graded temporary veneer for mimicking a natural look., Result: Mechanically, all composition result in adequate bending strength with maximum achievable strength of 111.64 MPa. At the same time, the composite color was affected by each constituent differently. The L* value, which indicates the color lightness of the composite, was considerably tuned by the TiO 2 pigment, whereas Ba 2 SiO 4 filler only triggered minor changes. Photoinitiator concentration significantly affected the yellowness, indicated by the increased b* value. Similar tendency also observed toward the calculated TP and WI D as well. Based on these evaluations, color-graded temporary veneer successfully generated, matching the VITA A3, A2, and B1 shades gradation. However, the stability of the composite color decreased at high amounts of Ba 2 SiO 4 and photoinitiator., Significance: The study presents a composition guide for fabricating temporary patient-specific color-graded veneer. It provides insights on the effect of the constituent material on dental esthetics., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate the influence of the tooth shade, type of resin composite and cavity configuration on the color adjustment of single-shade and group shade resin composites., Methods: Class I and V cavities were prepared in artificial acrylic mandibular right molars with different shades - A1, A2, A3, A3.5 and A4. Three single-shade (OMN, UNI, CHA) and two group shade (FIL, HAR) resin composites were evaluated. Seventy-five observers, including dentists, dental students and laypersons (n = 25), participated in the study. A psychophysical experiment based on visual assessments of the color matching between each tooth and each restoration was ranked from 0 (excellent match) to 4 (huge mismatch), and mean frequencies (%) were calculated. Visual color differences among composite materials and tooth shades were statistically tested (P < 0.05)., Results: The results showed highest percentages of unacceptable color mismatches for class V compared to class I restorations, especially for more chromatic tooth shades (A3.5 and A4). The percentage of ratings of acceptability was higher for laypersons group. For class V, OMN presented significant difference only from UNI in tooth shades A1, A2, A3 and A4. However, for class I, OMN presented significant differences with CHA for A1, A2 and A4, and with HAR and FIL for A1., Conclusions: Class I resin composite restorations exhibit superior color matching than Class V, with lighter and low chroma tooth shades demonstrating better color adjustment. The color matching of both cavity configurations is comparable for single and group shade resin composites., Clinical Significance: Cavity configuration and tooth shade may impact color matching of single and group shade resin composites. This study demonstrates superior color matching in class I configurations over class V for both single and group shade resin composites. Additionally, restorations placed in teeth with lighter shades exhibit more favorable color adjustment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: To evaluate the influence of abutment material, cement thickness, and crown type on the esthetics of implant supported restorations., Material and Methods: In total, 60 specimens were prepared to represent six abutment groups: Group PA &#61; pink-anodized Ti; Group GA &#61; gold-anodized Ti; Group T &#61; nonanodized Ti; Group H &#61; hybrid (Ti &#43; zirconia); Group P &#61; PEEK (Ti &#43; PEEK); and Group C &#61; composite resin (control). Crown specimens (n &#61; 120) were obtained from Vita Enamic (VE) and Vita Suprinity (VS). Two cement thicknesses (0.1 and 0.2 mm) were used. The color values of crown configura:ons were measured and ΔE00* values were calculated. Statistical analyses included were Shapiro Wilk, three-way ANOVA, and Tukey HSD tests (P ≤ .05)., Results: Abutment (P < .001) and crown materials (P &#61; .001) had a significant effect on ΔE00* values, while cement thickness did not. Groups PA and H resulted in significantly lower mean ΔE00* values than other abutments, whereas Group T revealed the highest. Unlike VS, cement thicknesses created a significant difference on the ΔE00* values for VE (P ≤.05)., Conclusions: Pink-anodized Ti or hybrid abutments for VE and pink- or goldanodized Ti for VS seem to be better options, in terms of color change. Cement thickness of 0.1 mm resulted in higher ΔE00* value than 0.2 mm for VE (P ≤ .05).

Purpose: To compare the masking ability of monolithic CAD/CAM veneers placed over different resin cement shades and substrate colors., Materials and Methods: Veneers were milled from four different monolithic CAD/CAM restorative materials: feldspathic ceramic (VMII), lithium disilicate ceramic (Emax CAD), zirconiareinforced lithium silicate ceramic (VS), and high-translucency zirconia ceramic (YZ-XT). Veneers were luted on natural tooth-colored (ND1) or discolored substrates (ND3 or ND5) using two different resin cement shades (opaque white or translucent). Each CAD/CAM material, resin cement shade, and substrate combination comprised 9 sample veneers (N &#61; 216). Color parameters were obtained using a dental spectrophotometer before and after luting. Color differences (ΔE00) were calculated using CIEDE2000 formula and compared to perceptibility (P &#61; .81 ΔE00 units) and acceptability (AT &#61; 1.77 ΔE00 units) visual thresholds. Color variation data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests with Bonferroni-Holm correction (α &#61; .05)., Results: The highest ΔE00 value was obtained in the VMII group placed over a discolored substrate, followed by the Emax CAD, YZ-XT, and VS groups. The effect of material types on ΔE00 values was significantly observed when the veneers were luted on discolored substrates using translucent resin cement (P < .05)., Conclusions: Restorative material type, substrate color, and resin cement shade affect the masking ability of monolithic CAD/CAM laminate veneers.

Statement of Problem: Shade selection is a challenge in restorative dentistry. While single-shade composite resins may simplify this process, whether the color mismatch between this composite resin and the substrate is within acceptable levels to ensure successful outcomes is unclear., Purpose: The purpose of this in vitro study was to assess the influence of background and surrounding shade, thickness, and proximity to the surrounding on color mismatch when shaded and single-shade composite resins are used in the center of an enamel layer., Material and Methods: Two-layer specimens mimicking dentin (the background) and enamel (the surrounding and center) were prepared. Two shades were used for the background and the surrounding layer (OA1/A1 and OA3/A3). At the Ø3-mm center, 2 single-shade composite resins were placed, Omnichroma (OM) and Admira Fusion x-tra (FU), and also shaded composite resins A1, WE, A3, and C2. For the OA1/A1 background and surrounding, shades A1 and WE served as positive controls, while the A3 and C2 were negative controls. For OA3/A3, these controls were reversed. Two enamel layer thicknesses were evaluated (0.5- and 1.0-mm). Reflectance measurements were made at 0.0, 1.0, 2.0, and 2.5 mm from the center. Color differences were calculated between those at 2.5 mm and at other distances (ΔE 0, ΔE 1, and ΔE 2 ). Data analysis employed a 4-way repeated measure ANOVA with Bonferroni corrections for the pair-wise comparisons (α=.05)., Results: Background and surrounding shade, central shade, distance, and thickness affected color mismatch (P<.05). For the OA1/A1 specimens, single-shade color mismatch values were found between both the positive and negative controls (P<.05). For the OA3/A3 specimens, the color mismatch did not differ significantly from that of negative controls (P>.05). No difference was found between ΔE 0 and ΔE 1 , but each was distinct from ΔE 2 . Thickness did not affect the color mismatch of the single-shade composite resins (P<.05)., Conclusions: Single-shade composite resins for enamel replacement showed higher color mismatches compared with positive controls., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: The effect of various gingival colors on the color differences of laminate veneers is unclear and comparative evaluations should be documented., Purpose: The purpose of this in vitro study was to investigate the influence of different gingival colors on the color differences of laminate veneers., Material and Methods: Five maxillary typodonts were used to obtain study models using 5 different gingival colors: light pink (LP), dark pink (DP), orange (Or), brown (Br), and violet (V). A total of 45 laminate veneers were milled using A1-shaded lithium disilicate ceramic and cemented on natural tooth-colored substrates. Color parameters were assessed using a spectroradiometer at 3 measurement areas (cervical third, mid-third, and incisal third) along the midline of laminate veneer with a focus measuring diameter of 1 mm. Color differences (∆E* ab and ∆E 00 ) were calculated and compared with perceptibility (PT: ∆E* ab =1.22, ΔE 00 =0.81) and acceptability (AT: ∆E* ab =2.66, ΔE 00 =1.77) visual thresholds. Color variation data were statistically analyzed using 2-way ANOVA and Tukey HSD tests (α=.05)., Results: Two-way ANOVA results of the ∆E* ab values revealed significant interaction between the gingival color and the measurement area (P=.002). The ∆E* ab and ΔE 00 values of laminate veneers were significantly higher in the LP-V group that presented values above AT (P<.001). Measurement area significantly influenced ∆E values of laminate veneers (P<.001). Greater ∆E values were registered at the measurement area of the cervical third in the groups of LP-DP, LP-Br, LP-V, and Or-V. Regardless of the measurement area, ∆E 00 values below AT were obtained for the gingival color groups of LP-Or, DP-Or, DP-Br, and DP-V., Conclusions: Gingival color influenced the color differences of laminate veneers. When the gingival color was a darker gingival color, rather than light pink, the color difference increased, especially at the measurement area of the cervical third., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: Matching the shade selected and the final color of a ceramic restoration is challenging, and studies on matching monolithic ceramics to the shade selected are lacking., Purpose: The purpose of this in vitro study was to compare the color match of monolithic lithium disilicate (LDS), zirconia-reinforced lithium silicate (ZLS), presintered zirconia-reinforced lithium silicate (PS-ZLS), polymer-infiltrated ceramic network (PICN), and multilayer zirconia with the 3 modes of the VITA Classical shade guide., Material and Methods: This study was performed on 50 rectangular plates (14×12×1 mm) of 5 types of ceramics with A2 shade (n=10). Zirconia specimens were evaluated in 3 locations: incisal, medial, and cervical thirds. The color coordinates of the specimens of all 7 groups were measured on #3 and #8 Ivoclar Natural Die Color material by using a reflective spectrophotometer. The color coordinates of A2 VITA shade were measured in 5 modes: without backing placed in specimen holder, shade tab on the backgrounds #3 and #8, and 1-mm-thick shade tab on the backgrounds #3 and #8. The color difference of each specimen with 3 modes of A2 shade (without backing and on similar backgrounds) was calculated by using the ΔE 00 formula, and comparison among groups was performed by using 2-way ANOVA and Tamhane post hoc tests. The comparison of ΔE 00 between the values obtained from backgrounds #3 and #8 was performed by using the independent t test (α=.05)., Results: In both backgrounds, statistically significant differences were found between the studied groups and VITA shade (P<.001). In most situations, the amount of color difference was lowest for the "shade tab on the backgrounds" mode. On background #3, the highest color difference was related to ZLS (6.48 ±0.23), and the lowest values were observed in the PICN group (1.02 ±0.31). On background #8, the highest color difference was related to ZLS compared with the "without backing" mode (8.62 ±0.27), and the lowest values were reported for ZLS compared with the "shade tab on the backgrounds" mode (1.27 ±0.44). The independent t test showed a statistically significant color difference on the 2 different backgrounds for all situations (P<.001)., Conclusions: Color selection of monolithic ceramics with the VITA Classical shade guide is improved by placing the VITA tabs on a similar background. Background color has a significant effect on the final shade of the monolithic ceramics. Choosing the correct color for LDS, ZLS, and PS-ZLS requires more care than for PICN and zirconia., (Copyright © 2022 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Objectives: The purpose of this bibliometric analysis is to identify the 100 most cited articles and delve into citation metrics to gain insights into the evolving trends in shade-matching methods in dentistry., Material and Methods: Following PRISMA guidelines, two reviewers conducted a structured search in Scopus using keyword-based search strings. The top 100 articles were selected based on predefined criteria, and their bibliometric data were extracted. Harzing's Publish Or Perish and VOSviewer were used to generate the bibliographic network., Results: Between 1989 and 2017, the top 100 articles were published and obtained citations ranging from 560 to 48. Twenty-eight articles received over 100 citations, deemed classic. The Journal of Prosthetic Dentistry and the United States of America were the primary contributors. In-vitro experimental studies employing restorative material samples were prevalent, with spectrophotometers being the favored method of color analysis. Using Python, Spearman's correlation coefficient resealed positive correlations between citation count and age of publication (r = 0.16, p = 0.12) and between citation count and the impact factor of the journal (r = 0.35, p < 0.05). However, a negative correlation was observed between citation density and age of publication (r = -0.46, p < 0.05)., Conclusions: This study demonstrated a significant upward trajectory of citation count in shade-matching in dentistry, reflecting high-quality scientific contributions., (© 2024 The Author(s). Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.)

Objective: This article aims to describe a systematic method for tooth color reproduction with ceramics restorations employing artificial intelligence (AI) software named Matisse. It provides a comprehensive analysis of the entire process, beginning with shade-taking and extending to ceramic application in a complex clinical case in the anterior region-specifically, a single central restoration supported by an implant., Clinical Considerations: The clinical case presented highlights the potential of Matisse software for generating ceramic (inSync-Jensen Dental, USA) and staining (Miyo-Jensen Dental, USA) recipes over a zirconia abutment (Katana-Noritake Dental, Japan). This approach achieves an optimal single central restoration utilizing CAD-CAM and layering techniques., Conclusions: The systematic method employing the Matisse software achieved accurate color reproduction for a single central restoration supported by an implant. This result was achieved by the dental ceramist within the first attempt and without seeing the patient in the entire process., Clinical Significance: The Matisse AI-assisted protocol offers a systematic and scientifically grounded method for color reproduction in dentistry for indirect restorations., (© 2024 The Author(s). Journal of Esthetic and Restorative Dentistry published by Wiley Periodicals LLC.)

Objective: This article aims to demonstrate the clinical application of a comprehensive workflow that integrates digital tools for accurate color matching, and its immediate implementation in the restoration of anterior teeth., Clinical Considerations: Two patients demonstrating dissatisfaction regarding a maxillary central incisor had an old restoration replaced resorting to a digital workflow to enhance the predictability of the new direct restoration. OptiShade allowed the precise assessment of tooth color and the CompoShade application provided precise color and material selection, as well as the determination of a layering strategy. Precision and accuracy of the colorimeter and the composite layering application were demonstrated clinically in vivo., Conclusions: Implementing a digital workflow with the integration of OptiShade measurements and the CompoShade layering recipe calculation, as well as the respective realistic try-in, enables the achievement of precise color matching for anterior composite restorations., Clinical Significance: The employment of a digital colorimeter and layering recipes simplify shade matching, and optimizes composite resin clinical use and success. The implementation of a realistic try-in, previous to the definitive restoration, allows the clinician to perform any adjustments if needed., (© 2024 Wiley Periodicals LLC.)

Recent composites are being developed to simplify shade matching in composite restorations. Only a limited amount of research has been conducted to determine the optical performance of this newly introduced composite in this area. This study investigated the Omnichroma (OMN) color matching (a single shade composite within type-I restorations) via simulated clinical cavities. A total of 72 frames were created by occupying the mold with Estelite Σ Quick (ES) of A1, A2, and A3 shades ( n = 24). Each shade of composite frame was divided into three subgroups ( n = 8) according to cavity dimension (width = 2, 3, and 4 mm/depth = 2 mm). Cavities were filled with Omnichroma. Color parameters were calculated based on CIEDE2000 (ΔE00) using a non-contact spectrophotometer. Finally, the data were analyzed using a two-way ANOVA (the Tukey HSD test) ( P = 0.05). The surrounding frame color significantly affected the color-matching capacity of OMN ( P < 0.0001). Groups A1 and A3 showed the lowest and highest amounts of ΔE00, respectively. The cavity width also influenced the color-matching ability of OMN ( P < 0.0001) significantly. According to the results, 4 mm cavity width showed the lowest amount of ΔE00, and 2 mm showed the highest amount. Monochromatic composites (OMN) did not match colors well in Class I cavities in posterior teeth. In cases of teeth with less chromatic surroundings, OMN matched shades better. OMN could better match shades in posterior teeth with wider cavities., Competing Interests: The authors declare no conflict of interest., (© 2024 The Author(s).)

This study evaluated the effects of surrounding and background shades on the color adjustment potential (CAP) and visual color match of two single-shade composites, Vittra APS Unique and Charisma Diamond One. Cylinder-shaped specimens were constructed, consisting of either single-shade composites alone (simple) or composites surrounded by the Forma material at shades A1 or A3 (dual). Simple specimens using only the Forma at the specified shades were also prepared. Color measurements of simple specimens were taken against a gray background using a spectrophotometer. For dual specimens, the color of the inner composite was measured against a gray or chromatic (the same shade as the outer composite) background. Color differences (ΔE00) between the single-shade composites and the A1/A3 composite were calculated. CAP was determined by comparing data from simple and dual specimens. Four experienced dentists scored the color match (perfect to unacceptable) for each specimen using a viewing booth illuminated by an illuminant D65. Data were analyzed with repeated-measures ANOVA and the Kruskal-Wallis test. The results showed that both single-shade composites showed the lowest color discrepancies when they were compared to A1 and A3. Using a chromatic background only significantly affected the CAP when the outer composite was A3. The visual analysis showed poor color matches between the single-shade and control chromatic composites, except for Charisma Diamond One surrounded by A1. In conclusion, the CAP values of the evaluated single-shade composites were impacted by both surrounding shade and background color, and the color match of these materials tended to be poor.

Background: The color adjustment potential of resin composites depends on the specific characteristics of the surrounding structures. The authors evaluated the influence of cavity wall thickness on CIEDE2000 color adjustment potential (CAP 00 ) of single-shade composites using the CIEDE2000 color difference (ΔE 00 ) formula., Methods: Two types of specimens were produced: single, using Vittra APS color DA3 (FGM Dental), Vittra APS Unique (VU) (FGM Dental), and Omnichroma (Tokuyama Dental) composites; and dual, using Vittra APS color DA3, but with cavity wall thicknesses of 3, 2, or 1 mm, restored with VU or Omnichroma. CIEL∗a∗b∗ color coordinates were obtained from digital photographs of the specimens at different locations, and ΔE 00 and CAP 00 were calculated. Statistical analysis included 2-way analysis of variance, Kruskal-Wallis, Holm-Sidak, Student-Newman-Keuls, Wilcoxon signed rank, and paired t tests (α = 5%)., Results: Cavity walls 1-mm-thick had higher ΔE 00 values and lower CAP 00 values, particularly for VU (P < .05). Restorations matched better with the control at the periphery than the central area (P < .001). Overall ΔE 00 means exceeded the color perceptibility threshold (ie, 0.8) and the acceptability threshold (ie, 1.8). Color differences (between center of restoration and control composite) were moderately unacceptable for 3-mm and 2-mm thicknesses and extremely unacceptable for 1-mm thickness. Both composites had a ΔE 00 color shift predominately determined by means of the lightness difference. Positive CAP 00 values were found for VU and Omnichroma., Conclusions: Wall thickness, especially at 1 mm, negatively impacted the color of single- shade composites. This effect was more pronounced for VU, affecting mainly the restoration's central area., Practical Implications: Color matching ability depends on the structural and material characteristics, and clinicians should be attentive to these factors when using single-shade resin composites., Competing Interests: Disclosure Drs. Castro and Durand did not report any disclosures., (Copyright © 2024 American Dental Association. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: The impact of different coloring liquid shades and dipping times on the color, transparency, and flexural strength of monolithic zirconia ceramics is unclear., Purpose: The purpose of this in vitro study was to evaluate the effects of different coloring liquid shades (A2, 3M2, and 5M2) and dipping times (no dipping, 30 seconds, 60 seconds, and 90 seconds) on the color difference (ΔE 00 ), relative translucency parameter (ΔRTP 00 ), and 3-point flexural strength (σ) of monolithic zirconia ceramics., Material and Methods: Yttria-stabilized zirconia (3Y-TZP, 3 mol%) was cut into Ø16×1.2-mm plates (n=10) and 25×4×1.2-mm bars (n=15), which were colored using 3 shades of coloring liquid at 4 dipping times. Color coordinates were measured on a gray background by using a digital spectrophotometer with an integrating sphere attachment. The color and translucency differences were evaluated using 50:50% perceptibility (PT 00 and TPT 00 ) and acceptability (AT 00 and TAT 00 ) thresholds. The 3-point flexural strengths of the bar-shaped specimens were measured using a universal testing machine and analyzed using the Weibull distribution to calculate the Weibull modulus (m) and characteristic fracture strength (σ 0 ). The data were analyzed with the 2-way ANOVA, Kruskal-Wallis, and LSD post hoc tests (α=.05)., Results: Both shade and dipping time significantly affected the color and translucency of monolithic zirconia (P<.001). The ΔE 00 was above the PT 00 for all groups, with only 3M2-90 and A2-60 being below the AT 00 . The main cause of color differences was the difference in lightness. Only A2 showed ΔRTP 00 below the TPT 00 (A2-30 (ΔRTP 00 =0.26), A2-60 (ΔRTP 00 =0.29), and A2-90 (ΔRTP 00 =0.46)). All experimental groups showed translucency differences below TAT 00 . In addition, only the dipping time had a significant effect on the flexural strength of zirconia (P<.001)., Conclusions: The optical properties of monolithic zirconia ceramics were affected by the shade and dipping time of the coloring liquid. The mismatch in lightness was the main reason for the color difference. The dipping time affects the flexural strength of monolithic zirconia, whereas the shade of the coloring liquid did not seem to influence flexural strength., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate the shade-matching ability of single-shade resin-based composite restorations in different thicknesses using both instrumental and visual techniques., Methods and Materials: Cavities with 4 mm diameter and 2 mm (n=96) or 3 mm (n=96) depth were prepared in acrylic incisor teeth of shades A2, A3, B3, and C2 and restored with three single-shade resin composites, Omnichroma (Tokuyama Dental America, Encinitas, CA, USA [OM]), Vittra APS Unique (FGM Dental Group, Joinville, SC, Brazil [VU]), Zenchroma (President Dental, Allershausen, Germany [ZC]), and a microhybrid resin composite (Filtek 3M Z250 3M ESPE, St Paul, MN, USA [FZ]) of A2, A3, B3, and C2 shades. Readings were obtained using VITA Easyshade V spectrophotometer for the teeth and restorations. The CIEDE2000 (ΔE00) color difference formula was used, and the values were assessed using three-way analysis of variance (ANOVA). Forty-eight evaluators graded the shade match of 32 different specimens visually as (A) best shade match, (B) intermediate shade match, and (C) poor shade match., Results: FZ material achieved satisfactory matches for both thicknesses, across all shades, and OM material demonstrated statistically significant lower shade matches than the ZC and the FZ materials (p<0.05). VU exhibited poor shade match with the highest ΔE00 value on C2 shade. According to the visual examination, the best shade matches were observed for FZ on A3-shade and ZC on C2-shade teeth., Conclusions: Shade matching for 2 mm and 3 mm-thick composite resin restorations is material- and tooth-shade dependent., (©Operative Dentistry, 2024.)

Statement of Problem: Achieving accurate tooth color is important in esthetic dental treatments; however, clinical studies evaluating how ceramic veneer procedures affect color alterations are lacking., Purpose: 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., Material and Methods: 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 , ΔE 00 , 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 , ΔE 00 , SGU), Friedman test (ΔSGU), and the Pearson test was used to correlate veneer thickness and color change (ΔE ab , ΔE 00 , ΔSGU) (α=.05)., Results: 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 , ΔE 00 , 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)., Conclusions: 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)., (Copyright © 2022 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Shade matching of extraoral prostheses is completed by mixing pigments and rayon flocking into medical-grade silicone and using a carrier to evaluate the color match. This process does not account for how material thickness affects the appearance of the silicone. This clinical case report discusses an innovative way to match the patient's skin tone using a digitally designed gradated silicone carrier and how this device allows for the assessment of shade from the thin marginal edge to 5 mm thickness., (© 2023 by the American College of Prosthodontists.)

The effect of a novel nano-ceramic coating (TiO2) using an atomic layer deposition (ALD) technique on the surface of polymethyl methacrylate (PMMA) material was investigated. The patients’ and clinicians’ perception and acceptance of the PMMA color with TiO2 coating were also examined. In vitro color measurement was performed on thirty specimens (light, original, and dark pink) before and after TiO2 coating. Patients’ and clinicians’ perception and acceptance of color changes on PMMA were measured and compared. Descriptive and analytic statistics were analyzed (a = 0.05). TiO2 films were successfully deposited on the PMMA specimen by the ALD technique. Color changes after TiO2 coating were observed on all three PMMA shades, significantly higher than the established 50:50% perceptibility threshold, but below the established 50:50% acceptability threshold. The percentage of patients that perceived a color difference after TiO2 coating were 83.3%, 63.9%, and 77.8% for light, original, and dark pink, respectively. The percentages of clinicians that were satisfied with the color difference were 96.4%, 80%, and 69.2% for light, original, and dark pink, respectively. Color changes after TiO2 coating were observed, but below the acceptable threshold. The clinical survey demonstrated that a color difference was perceived but was clinically acceptable. In general, laypeople have lower perception and higher acceptance of changes in PMMA color than clinicians.

Background: Effects of ceramic translucency, layer thickness, and substrate colour on the shade of lithium disilicate glass-ceramic restorations proved to be significant in several studies, however, quantitative, numerical results on the relationship between the colour difference and these parameters are still lacking. The purpose of this in vitro study was to quantitatively determine how the colour reproduction ability of a lithium disilicate glass-ceramic is affected by its translucency, layer thickness, and substrate colour., Methods: Ceramic samples were prepared from A2 shade IPS e.max CAD blocks with high and low translucencies (HT and LT) in a thickness range of 0.5-2.5 mm (+/- 0.05 mm). Layered samples were acquired utilizing composite substrates in 9 shades; transparent try-in paste was used. The spectral reflectance of the specimens was assessed under D65 standard illumination with a Konica Minolta CM-3720d spectrophotometer. The CIEDE2000 colour difference (ΔE 00 ) between two samples was analysed using perceptibility and acceptability thresholds set at 50:50%. Statistical analysis involved linear regression analysis and the Kruskal-Wallis test., Results: An increase in the thickness of 0.5 mm reduced the ΔE 00 of the HT samples to 72.8%, and that of the T samples to 71.1% (p < 0.0001). 7 substrates with HT and LT specimens had significantly different results from the mean (p < 0.05). A thickness of 0.5 mm is not sufficient to achieve an acceptable result at any level of translucency, while the low translucency ceramic at a thickness of 1.5 mm gave acceptable results, except for severely discoloured substrates (ND8 and ND9)., Conclusions: The colour reproduction ability of lithium disilicate glass-ceramics is significantly affected by their translucency, layer thickness, and 7 substrates out of 9 substrates examined., (© 2024. The Author(s).)

Direct composite restorations are among the most common and useful in dentistry, but shade matching can present challenges. Shade matching with direct composites is often labor intensive and technique sensitive. Utilizing a single-shade composite can simplify the process, reducing the time spent and skill required as well as overall stress on the clinician. In the case presented, which involved multiple restorations in all four quadrants, a single-shade composite was utilized to streamline the workflow and achieve an excellent outcome.

Purpose: To investigate the effect of different abutments and crowns on the color of implant-supported restorations., Methods: Zirconia and lithium disilicate (e.max) disks with A2 shade were fabricated to represent two crowns. The implant abutments were untreated titanium, opaqued titanium, anodized titanium, A2 shade zirconia and white zirconia. 4.0 mm-thickness zirconia and e.max specimens were used as references respectively. The crowns were placed on tested abutments with a drop of clear glycerin between them and the color was measured using a digital spectrophotometer. CIELab values were recorded to evaluate color differences (ΔE) between tested specimens and the references., Results: Titanium abutments presented higher color differences than zirconia. The ΔE values with untreated titanium were higher than those with opaqued titanium. No differences were found between untreated titanium and anodized titanium for zirconia crowns. The ΔE values of zirconia crowns showed no significant differences between shade A2 zirconia and white zirconia abutments; e.max crowns showed a significant difference. The zirconia crown ΔE values were lower than those of e.max for all titanium and A2 zirconia abutments. Lithium disilicate crowns and zirconia abutments may be more suitable for implant-supported restorations. Opaqued titanium abutment may improve color in esthetic regions when a ceramic abutment cannot be used., Clinical Significance: Lithium disilicate crowns and zirconia abutments may be an effective method to achieve excellent color matching in esthetic regions with implant-supported restorations., Competing Interests: The authors declared no conflict of interest. This work was supported by the Clinical Research Program of the 9th People's Hospital affiliated with Shanghai Jiao Tong University School of Medicine (JYLJ201908). Lan Jia and Lijuan Ye contributed equally to this work and should be considered co-corresponding authors., (Copyright©American Journal of Dentistry.)

Introduction: Shade matching is an essential procedure to obtain an esthetic prosthesis. The Direct Visual Shade Matching (DSM) method using shade guides is the most used method by dentists. However, The Indirect Visual Digital Shade Matching (ISM) method based on digital imaging is concerned to be reliable and useful in determining shade matching in dental practice. Several factors such as method, clinical experience, and gender can affect the success of shade matching., Aim of the Study: This study aimed to compare these two methods and evaluate the effect of experience and gender on the results., Materials and Methods: Three volunteers' maxillary central incisor teeth were evaluated using (DSM) and (ISM) methods by 87 examiners (42 males, 45 females). These examiners were further divided into three groups based on their clinical experience: Undergraduate Preclinical Dental Students (UPDS) with 31 examiners, Undergraduate Clinical Dental Students (UCDS) with 34 examiners, and Postgraduate Dental Students from the Department of Prosthodontics (PDS) with 22 examiners. The spectrophotometer device results of three teeth were considered as a reference for shade matching. Statistical analyses of the data were performed using Kruskal-Wallis, Mann-Whitney U, and Chi-square tests., Results: No significant difference was found between indirect and direct methods according to Perfect Matches (p > 0.05). However, according to Shade Matching Deviation Score (SMDS) values a statistically significant difference was found between the two methods where the best result was obtained with the ISM method (p < 0.05). There was a significant difference between the PDS group and the other two groups in terms of clinical experience (p < 0.05). There was no significant difference between gender groups (p > 0.05)., Conclusion: Digital images, captured under standardized lighting conditions, may serve as a reliable alternative method for direct shade matching. The (ISM) method requires a camera, related accessories, and computer skills. However, as these tools are commonly available nowadays, the focus for practitioners should be on effectively learning and applying these tools to achieve the best results. While clinical experience plays a significant role in the shade matching process, gender does not appear to have a substantial influence., Clinical Significance: This study found no significant differences between the (DSM) and (ISM) methods, leaving the clinical relevance of this method open to debate. However, the ISM method yielded superior responses. Despite requiring specialized tools, conditions, and training, the widespread use of cameras and computers in modern clinics makes the necessary equipment and software readily available. This method enhances clinician-technician communication, potentially improving prosthesis esthetics and patient satisfaction, especially for less experienced clinicians or those with color deficiencies. Further research is crucial to determine its clinical significance., (© 2024 Wiley Periodicals LLC.)

Purpose. The aim of this study was to evaluate biaxial flexural strength and hardness of colored monolithic zirconia after dipping in different time intervals of coloring solution. Materials and Methods. Disk shaped specimens were prepared from monolithic zirconia (Eclipse V2.0, AMS, Gimpo, Korea). Four experimental groups were categorized (n = 12) due to coloring time (PU (0s); ST (8s); OV (1 min); PS (preshade)), to evaluate biaxial flexural strength and Vickers hardness. After fracture, X-ray diffraction analysis was performed using fractured specimens. Results were analyzed with one-way ANOVA test. Results. There was no significant difference between groups in the biaxial flexural strength test. However, in the Vickers hardness test, the group with standard dipping time (ST) showed significantly higher value than the group without dipping in coloring liquid (PU)(P=.038). Also, there was no significant difference in the rest of the groups (P>.05). As a result of X-ray diffraction analysis, specific peaks of tetragonal phase were shown and the volume of monoclinic phase fraction was lower than 25%. Conclusion. Although this study has several limitations, coloring liquids had no significant effect on biaxial flexural strength. Vickers hardness was significantly different between the group to which the coloring liquid was applied and the group to which the coloring solution was not applied, but there was no significant difference between the other groups. Also, the flexural strength of monolithic zirconia corresponds to Class 5 of the minimal flexural strength standard according to the use of dental ceramics. [ABSTRACT FROM AUTHOR]

How to cite this article: Abhishek G. The Evolving Landscape of Shade Matching: From Softwares to Mobile Apps. J Contemp Dent Pract 2024;25(5):403-404. Keywords: Digital shade guide, Mobile shade matching.

Objectives: Natural teeth and dental restorations present with various shades and levels of translucency. This study aimed to determine whether these variations in ceramic crowns and scan powder application affect the trueness of intraoral scanners., Methods: Eight identical premade resin typodonts, each prepared for a crown on the maxillary right second molar, were used. Eight lithium disilicate crowns, distinguished by two levels of translucency (high and low) and four shades (BL1, A2, A3, and A4), were fabricated to an identical design and cemented onto each typodont, providing eight distinct experimental groups (2 levels of translucency × 4 shades). Reference scans were acquired using a desktop scanner. Test scans were performed ten times for each experimental group using two different intraoral scanners (Medit i700 and CEREC Primescan AC), with and without the application of scan powder (n = 10). Three-dimensional metrology software was used to assess the trueness of the intraoral scan datasets. Statistical analysis involved the Kruskal-Wallis H test, Mann-Whitney U test, and independent t-test (α=0.05)., Results: For powder-free intraoral scan datasets, the crown shade did not significantly affect trueness within each translucency group (P = 1.000). For both intraoral scanners, compared with low translucency groups, higher marked deviations were exhibited by high translucency groups (P<.001). Scan powder use largely mitigated these differences (P>.05) and enhanced the trueness of the intraoral scan (P<.01)., Conclusions: Shade did not significantly influence the trueness of intraoral scans. High-translucency crowns were scanned with less accuracy than were low-translucency crowns., Clinical Significance: Unlike tooth shade, translucency significantly affected the accuracy of intraoral scans. Therefore, considering the use of scan powder when scanning objects with high translucency may be beneficial., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Statement of Problem: Clinical information regarding the color stability of lithium disilicate veneers by using different methods of evaluation is scarce., Purpose: This clinical trial aimed to evaluate whether digital photographs are a reliable method of clinically assessing the color stability of lithium disilicate veneers. Standardized digital photographs (ELAB) were compared with the VITA Easyshade spectrophotometer (ES) at baseline and at a 6-month follow-up., Material and Methods: A split-mouth model was used in this randomized clinical trial to assess the performance of ceramic veneers (N=162), which were produced by either the CAD (IPS e.max CAD; n=81) or PRESS technique by heat pressing (IPS e.max PRESS; n=81), including the color dimension assessment. The ELAB evaluation was performed by making digital photographs with polarized light and a white balance (WhiBal) card. These data were transferred to the Adobe Lightroom CC2015 software program in RAW extension. The Digital Color Meter App (Apple) was used to measure L∗, a∗, and b∗ coordinates in this method. The ES color evaluation was performed with a spectrophotometer (Easy Shade) (control group) in the CIELab system. Measurements were performed 1 week after cementation (baseline) and at a 6-month follow-up. Data collected by the ELAB and ES methods were analyzed by a blinded calibrated operator to calculate ΔE by using the Mann-Whitney-Wilcoxon test (α=.05)., Results: For all periods, the comparison among ELAB and ES methods (P=.331), CAD×PRESS by ELAB (P=.658), and CAD×PRESS by ES (P=.833) showed no statistically significant differences., Conclusions: Standardized digital photographs (ELAB) were shown to be a straightforward and available resource for evaluating the color stability of lithium disilicate veneers, manufactured by CAD or PRESS., (Copyright © 2022 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: Visual color determination in clinics or dental offices should take place under reproducible environmental conditions. To reduce false tooth color measurements, daylight and illumination lamps (5000-7500 K) have been recommended. Those can be used either as stationary or mobile handheld illumination units. However, depending on the manufacturer, the handheld lights use different illuminance brightness, and whether the choice of unit affects shade selection is unclear., Purpose: The purpose of this in vitro study was to determine whether the mobile handheld light-emitting diode (LED) lighting unit shows a significantly better result in visual color determination than the conventional reference lighting unit., Material and Methods: Trained preclinical dental students (N=23) with a mean ±standard deviation age of 24 ±5 years participated in the study. Two color differentiation lamps (Smile lite 1620lx and Dialite Color 4450lx) (SL and DC) were each placed at a 15-cm distance to determine the color of the shade tabs (templates, N=10) with the VITA Linear Guide 3D Master in a double-blinded study. According to the manufacturer's recommendation, polarization filters were used with the Smile lite lamp., Results: Of N=220 shade determinations each, 31.8% (SL) and 33.2% (DC) were correct; the median (ΔE 00 ) and interquartile range were 0.96 (±3.32) for SL and 1.35 (±3.28) for DC. The differences between the groups were not statistically significant (P=.67)., Conclusions: The results show that the use of the mobile LED illumination unit did not improve color determination compared with the reference illumination. The different illumination intensities of 980 lux (SL) with a polarizing filter or 1500 lux (DC) did not have a positive effect., (Copyright © 2022 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: The choice of cleaning method is an important consideration for lengthening the serviceable time of facial prostheses as microbial organisms and biofilms could degrade facial prostheses and cause skin irritation. Whether microwave disinfection is a suitable cleaning method without degradation of the properties of a prosthesis is unclear., Purpose: The purpose of this in vitro study was to measure the color stability of 6 commonly used facial silicone elastomers after microwave disinfection over a simulated 1.5-year period., Material and Methods: Six different facial silicone elastomers: MDX4-4210, MDX4-4210/Type A, M511, A-2186, VST-50, and A-2000 were mixed with intrinsic silicone white opacifier (except for the control group) and subsequently combined with 4 silicone intrinsic pigment color groups: red (R), yellow (Y), burnt sienna (B), and a mixture of R+Y+B (M). The control group was a silicone elastomer without opacifier or pigment. Each of the 30 experimental groups consisted of 5 specimens (N=150). Five specimens were placed in a 250-mL Erlenmeyer flask filled with 160 mL of tap water. Seven flasks were then placed in a 660-W microwave oven. An exposure of 6 minutes was used according to the antimicrobial efficacy of microwave disinfection protocol on facial silicone prostheses with a final water temperature of 60 °C for 18 times (simulating 1.5 years of microwave disinfection with one 6-minute exposure monthly). A spectrophotometer was used to measure reflectance color change values (∆E). Color differences were calculated following CIELab (∆E* ab ) and CIEDE2000 (∆E00) formulae. ∆E* ab and ∆E00 were statistically analyzed by a linear mixed effects model with 3 factors (silicone type, color shade, and time) using the R Statistical software program (α=.05)., Results: Both ∆E* ab and ∆E00 of all silicone elastomers studied were less than the visual perceptibility thresholds (∆E* ab <1.1 and E00<0.7) and were considered clinically acceptable (∆E* ab <3.0 and E00<2.1) after the 1.5-year simulation of microwave disinfection. Yellow and blue pigments had more effect on MDX4-4210 and M511, while red pigment had more effect on MDX4-4210, MDX4-4210/Type A, and M511 (P<.05). Nevertheless, the values were still below the perceptibility threshold (∆E* ab ≤1.0 and E00<0.6)., Conclusions: All 6 facial silicone elastomers maintained clinically acceptable color after 18 months of exposure to microwave disinfection., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Purpose: To study the degree of accuracy in gingival shade matching of undergraduate students using a computer application., Materials and Methods: In total, 76 undergraduate dental students' gingival shade selection abilities were evaluated using an in-house developed computer application. A total of 15 intraoral gingival photographs and 21 pink gingival color porcelain samples were used. The environmental conditions were standardized, and no time limit was set for answering in the computer application., Results: Fourteen gingival color samples (66.6%) were not useful for representing the studied gingival shades. Not all natural gingival colors studied were represented within the 50.50% acceptability limits of the pink samples. There were no statistically significant differences between men and women in terms of "hit" percentages. The highest correlation coefficient (in absolute value) was for the L* coordinate (the darker the gingiva in the picture, the higher the hit rate for choosing the "ideal" shade tab); however, none of the linear correlation coefficients were statistically significant., Conclusions: Not all colors provided in the pink ceramic system were useful for subjective gingival selection. There were no statistically significant differences between male and female dental students in gingival color perception. The L* coordinate was the only one that influenced the correct perception of gingival color by dental students, and it did so more in women than in men.

Purpose: This study investigated the color stability of different commercially available silicone materials for facial prostheses upon exposure to everyday beverages. It was hypothesized that the beverages would not alter the color of the silicone under conditions simulating daily exposure., Methods: Sixty specimens were fabricated using two materials - VST-50 and Silfy - and exposed to commercially available cold mineral water, tea, or coffee. Specimen color was evaluated on days 1 and 15. The color was measured with a spectrophotometer based on CIELab system and color differences were calculated as ΔE. Statistical analysis was performed using the Kruskal-Wallis test and Mann-Whitney U test., Results: The mean ΔE values after 15 days of exposure to mineral water, cold green tea, and coffee were 1.016, 3.480, and 3.636 for VST-50 and 0.440, 0.798, and 1.425 for Silfy, respectively. Both materials showed significant differences in color, and VST-50 showed a greater color change than Silfy, especially for coffee., Conclusion: Pigmented silicone elastomers have low color stability, leading to an overall color change in silicone prostheses when exposed to pigmented beverages. Color changes in such prostheses can be mitigated by selecting materials with better color stability to extend their longevity.

Objectives: Determine visual 50:50% color difference acceptability thresholds (AT) for regions of the dental color space with varying chromaticity., Methods: A 40-observer panel belonging to two different groups (dentists and laypersons) evaluated 144 dental resin composites pairs (divided in three different sets of 48 pairs according to chroma value: Low Chroma (LC), Medium Chroma (MC) and High Chroma (HC) placed 40 cm away and inside of a viewing cabinet (D65 Standard light source; diffuse/0° geometry). A Takagi-Sugeno-Kang (TSK) fuzzy approximation was used for fitting the data points and calculate the 50:50% acceptability thresholds in CIEDE2000. A paired t-test was used to evaluate the statistical significance between thresholds differences and Bonferroni correction was applied., Results: The CIEDE2000 50:50% AT were ∆E 00  = 2.84, ∆E 00  = 2.31 and ∆E 00  = 1.80 for LC, MC and HC sets of sample pairs, respectively. The 50:50% AT values were statistically significant between the different sets of sample pairs, as well as the 50:50% AT values obtained for different observer groups., Conclusions: 50:50% CIEDE2000 acceptability thresholds for dentistry are significantly different depending on the chromaticity of the samples. Observers show higher acceptability for more achromatic samples (low chroma value) than for more chromatic samples., Clinical Significance: The difference in the AT for distinct regions of the dental color space can assist professionals as a quality control tool to assess clinical performance and interpret visual and instrumental findings in clinical dentistry, dental research, and subsequent standardization processes., (© 2023 Wiley Periodicals LLC.)

Objective: To evaluate the translucency of several monolithic zirconias (MZ) processed in various sintering ovens designed for single-visit, chairside use., Methods: Discs (n = 40) from zirconia blocks were fabricated for each MZ at manufacturer-recommended minimal thicknesses, as provided in each material's instructions for use: IPS e.max ZirCAD LT (ZLT); CEREC Zirconia+ (CZ+); 3M Chairside (3M); KATANA Zirconia (KT). Groups (n = 10) were sintered following manufacturer instructions for each oven: CEREC SpeedFire, Ivoclar CS4, Ivoclar CS6, and Ivoclar S2 (laboratory furnace control). Specimens were highly polished on one side and glazed on the other. Each side was measured with a spectrophotometer against white and black backgrounds to determine translucency parameter (TP) and contrast ratio (CR) values. Results for TP and CR for each material and oven combination were compared with a linear mixed model. Oven precision was evaluated using the Kruskall-Wallis test., Results: Glazed specimens were more translucent than polished ones (p < 0.001). ZLT and CZ+ were more translucent than 3M and KT regardless of the sintering oven (p < 0.01). Several oven/material combinations reached or exceeded the S2 oven TP: CS4 with CZ+ and 3M; CS6 with ZLT and KT (p < 0.01). SpeedFire was significantly less precise (p < 0.05) and produced lower TP values for ZLT, CZ+, and KT (p < 0.01). Results for TP and CR were highly correlated., Conclusions: MZ surface finish, material thickness, and oven used all had a significant effect on translucency. Some chairside-oriented solutions produced results with translucency equal to conventionally processed zirconia., Clinical Significance: The translucency of a ceramic restoration is an important factor in determining its esthetics. Clinicians desiring the most esthetic outcomes with monolithic zirconia should be aware of the significant effects that surface finishing, material thickness, and the sintering oven used can have on restoration translucency., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: The objective was to assess the repeatability of three spectrophotometers, based on the CIELCh factors and shadeguide reference measurements., Materials and Methods: Color analysis was performed using three devices: Rayplicker, Easyshade 4, and Easyshade V. Five repeated measures were performed by the same operator, on the right central maxillary incisor of 30 patients. The CIELCh factors were retrieved and the intra-class correlation was calculated. The Vita Classical and Vita 3D Master shadeguides were used to evaluate the respective Fleiss' Kappa factors., Results: Rayplicker and Easyshade V demonstrated strong intra-class correlation based on the CIELCh factors: 0.98, 0.99, and 0.91 for Rayplicker, and 0.95, 0.99, and 0.93 for Easyshade V, for the L*, C*, and h* parameters, respectively. Regarding the repeatability of the shadeguide data, while Easyshade 4 had the best repeatability when using the Vita Classical as a reference, Rayplicker and Easyshade V showed better repeatability when using the Vita 3D Master., Conclusion: These findings suggest that both Rayplicker and Easyshade V are reliable devices for measuring CIELCh parameters. In terms of shadeguide references, the reliability of spectrophotometers is generally lower compared to the CIELCh measurements., Clinical Significance: Given their good repeatability, both the Rayplicker and the Easyshade V spectrophotometers are reliable tools for prosthetic dental practices., (© 2024 The Authors. Journal of Esthetic and Restorative Dentistry published by Wiley Periodicals LLC.)

Objectives: The aim of this study was to evaluate the effect of clinical experience level on the shade matching accuracy in different dental occupational groups. Materials and methods: A total of 80 participants, assigned to one of four groups depending on the level of their clinical experience in shade matching: dental technicians (DTs), residents in prosthodontics (RPs), specialists in prosthodontics (SPs) and dental students (DSs) took part in the study. They were asked to use Tooth guide Training Box (TTB) and determine 15 standardized shade tabs using VITA 3D-Master shade guide. The number of mistakes in final test for each participant was recorded and accuracy was calculated. Color difference (ΔE) values for each shade were calculated from L*, a* and b* values. Differences in accuracy, mean ΔE values and mean error ΔE values between four different groups were examined. Results: No statistically significant differences were found between the groups regarding accuracy and mean ΔE values (p>0.05). The accuracy rate in four groups was 0.51±0.20 (DTs), 0,54±0.18 (RPs), 0.49±0.16 (SPs) and 0.55±0.14 (DSs), respectively. Mean ΔE values were 2.10±0.98 (DTs), 2.18±0.97 (RPs), 2.51±0.97 (SPs) and 2.08±0.86 (DSs), respectively. Regarding mean error ΔE values, DTs made errors with significantly less deviations compared to other groups (p

Background: This study aimed to evaluate the effect of different coloring techniques and surface treatment methods on the surface roughness of monolithic zirconia ceramic. Materials and Methods: In this in vitro study seventy two disk shaped monolithic zirconia (2 mm x 10 mm) were divided into three coloring techniques groups (white, internal staining, external staining) (n = 24). Each group was subdivided into four surface treatment subgroups (n = 6), as unpolished, polished with Shofu polishing kit, polished with dental direct polishing kit, and glazed. Profilometer was used to measure the Ra (roughness average) and Rz (roughness height) surface roughness values (µm) and scanning electron microscopy (SEM) for visual inspection of the surface morphology. The surface roughness parameters were calculated and analyzed with two-way ANOVA and Tukey's post hoc test (α= 0.05). Results: The coloring technique, surface treatment method, and interaction of these two parameters significantly affected the Ra and Rz parameters (P < 0.05). Concerning the surface treatment, the Rz value was significantly higher in the unpolished subgroup, followed by the glazed and polished subgroups. However, the two polishing systems were not significantly different. The internal staining group had significantly higher Rz value than the other staining method, when the specimens were glazed or polished with Shofu kit. SEM showed multiple scratches in unpolished samples which were smoothened by glazing and specially by polishing. Conclusion: Among all the studied surface treatment methods, the lowest surface roughness was observed in highly polished monolithic zirconia, which was even less than the glazed one. The internal staining method can create a rougher surface for some of the surface treatment methods. [ABSTRACT FROM AUTHOR]

Temporary restorations are of great importance for success in the course and completion of dental rehabilitations. In the face of substances transiting the oral cavity, color stability becomes essential for success during its use, mainly for the maintenance of aesthetics. The objective of the study was to evaluate the influence of the solutions of routine consumption on the color change of two materials used in the preparation of temporary restorations, comparing the stability of the acrylic resin with the bisacrylic resin. For the research, 60 samples were made, 30 of which were made of conventional acrylic resin (DencôrLay, Clássico Ind. And Com., São Paulo, SP, Brazil) and 30 of Protemp 4 bisacrylic resin (3M ESPE, St. Paul, MN) TO 1. The samples were divided into three groups (n = 10) according to the immersion medium: distilled water (control), Cola-Cola® and Coffee. The evaluation of the color change (ΔE) was evaluated according to the difference of the initital and final color (after 7 days of immersion) through the spectrophotometer (Vita Easyshade Advance 4.0; Vita-zahnfabrik). The results showed that the solutions presented significant staining potential, and that coffee provided the greatest color change for both resins tested (p <0.05). Regardless of the immersion medium, the bisacrylic resin presented the highest values of ΔE. It is concluded that coffee has a high staining potential over the provisional materials and that the bisacrylic resin has a lower color stability compared to the acrylic resin. [ABSTRACT FROM AUTHOR]