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Tejada-Casado M, Pérez MM, Della Bona A, Lübbe H, Ghinea R, Herrera LJ. Chroma-dependence of CIEDE2000 acceptability thresholds for dentistry. J ESTHET RESTOR DENT 2024; 36:469-476. [PMID: 37861306 DOI: 10.1111/jerd.13153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 09/25/2023] [Accepted: 10/07/2023] [Indexed: 10/21/2023]
Abstract
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 ∆E00 = 2.84, ∆E00 = 2.31 and ∆E00 = 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.
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Affiliation(s)
- Maria Tejada-Casado
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain
| | - María M Pérez
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain
| | - Alvaro Della Bona
- Post-Graduate Program in Dentistry, Dental School, University of Passo Fundo, Passo Fundo, RS, Brazil
| | - Henning Lübbe
- Vita Zahnfabrik H. Rauter GmbH & Co. KG, Bad-Säckingen, Germany
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain
- Department of Physics, University of Craiova, Craiova, Romania
| | - Luis Javier Herrera
- Department of Computer Architecture and Computer Technology, E.T.S.I.I.T. University of Granada, Granada, Spain
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Diamantopoulou S, Johnston WM, Ghinea R, Papazoglou E. Coverage error of three resin composite systems to vital unrestored maxillary anterior teeth. J ESTHET RESTOR DENT 2023; 35:352-359. [PMID: 35373479 DOI: 10.1111/jerd.12913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 03/05/2022] [Accepted: 03/20/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Define the color of anterior teeth of a selected population and correlate it (by using coverage error [CE] and the frequency of best match) with the final color of all possible enamel-dentine combinations of three different resin composite systems. MATERIALS AND METHODS Color of 636 vital unrestored anterior teeth (central incisors, lateral incisors and canines; n = 212) and disk specimens (12 mm diameter, varying thickness) corresponding to enamel-dentin combinations of all available enamel (0.5 mm and 1.0 mm thickness) and dentin shades (3.0 mm thickness) of Essentia, Enamel Plus HRi and IPS Empress Direct composite systems was measured using a clinical dental spectrophotometer (Spectroshade Micro). CE and frequency of best match for all composite systems were calculated for the measured in-vivo teeth color space. RESULTS Natural in-vivo teeth exhibit higher lightness when compared to enamel-dentin composite combinations, independently of the enamel thickness used. The best (lowest) CE was found for IPS Empress, while the highest values were found for Enamel Plus Hri independently of tooth type and enamel thickness (p < 0.001). The use of 0.5 mm instead of 1.0 mm enamel thickness within enamel-dentin composite combinations resulted in a lower CE for in-vivo tooth color (p < 0.001). CONCLUSIONS The color space defined by all possible enamel-dentin combinations of the studied resin composite systems does not fully match the color range of anterior teeth. All composite systems examined lack combinations with lightness values as high as the population's. IPS Empress Direct composite system represented better the in-vivo teeth color. CLINICAL SIGNIFICANCE The use of 0.5 mm enamel shade thickness is suggested when building layered restorations, as it provided better color coverage than using 1.0 mm thickness.
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Affiliation(s)
- Sofia Diamantopoulou
- Department of Operative Dentistry, School of Health Sciences, Faculty of Dentistry, University of Athens, Athens, Greece
| | - William M Johnston
- Division of Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio, USA
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain.,Department of Physics, Faculty of Science, University of Craiova, Craiova, Romania
| | - Efstratios Papazoglou
- Department of Operative Dentistry, School of Health Sciences, Faculty of Dentistry, University of Athens, Athens, Greece
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Tejada-Casado M, Ghinea R, Pérez MM, Ruiz-López J, Lübbe H, Herrera LJ. Development of Thickness-Dependent Predictive Methods for the Estimation of the CIEL*a*b* Color Coordinates of Monolithic and Layered Dental Resin Composites. Materials (Basel) 2023; 16:761. [PMID: 36676498 PMCID: PMC9864169 DOI: 10.3390/ma16020761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/07/2023] [Accepted: 01/09/2023] [Indexed: 06/17/2023]
Abstract
Usually, dentin and enamel shades are layered in dental restorations with the purpose of mimicking the natural appearance of teeth. The main objective of this study was to develop and assess accuracy of a color-prediction method for both monolithic and layered dental resin-based composites with varying shades and under different illuminants. A total of 15 different shades of VITAPAN Excell, VITAPAN Dentine and VITA Physiodens as well as VITA Enamel of five different thicknesses (0.5-2.5 mm range) were used to manufacture monolithic and layered samples. A non-contact spectroradiometer with CIE 45∘/0∘ geometry was used to measure the color of all samples over a standard ceramic black background. Second-degree polynomial regression was used as predictive method for CIE-L*a*b* color coordinates. Performance of predictive models was tested using the CIEDE2000 total color difference formula (ΔE00), while accuracy was evaluated by comparative assessment of ΔE00 with corresponding 50:50% acceptability (AT00) and perceptibly (PT00) thresholds for dentistry. A mean color difference between measured (real) and predicted color of ΔE00=1.71, with 62.86% of the color differences below AT00 and 28.57% below PT00, was registered for monolithic samples. For bi-layered samples, the mean color difference was roughly ΔE00=0.50, with generally 100% and more than 85% of the estimations below AT00 and PT00, respectively. The predictive method allowed highly accurate color estimations for both monolithic and layered dental resin-based composites with varying thicknesses and under different illuminations. These results could be useful to maximize the clinical success of dental restorations.
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Affiliation(s)
- Maria Tejada-Casado
- Department of Optics, Faculty of Science, Campus Fuentenueva, Edificio Mecenas, s/n., University of Granada, ibsGranada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18011 Granada, Spain
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, Campus Fuentenueva, Edificio Mecenas, s/n., University of Granada, ibsGranada, 18071 Granada, Spain
- Department of Physics, Faculty of Sciences, University of Craiova, 13 AI Cuza Street, 200585 Craiova, Romania
| | - María M. Pérez
- Department of Optics, Faculty of Science, Campus Fuentenueva, Edificio Mecenas, s/n., University of Granada, ibsGranada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18011 Granada, Spain
| | - Javier Ruiz-López
- Department of Optics, Faculty of Science, Campus Fuentenueva, Edificio Mecenas, s/n., University of Granada, ibsGranada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18011 Granada, Spain
| | - Henning Lübbe
- Vita Zahnfabrik H. Rauter GmbH & Co. KG, Ballyweg 6, 79713 Bad-Säckingen, Germany
| | - Luis Javier Herrera
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18011 Granada, Spain
- Computer Architecture and Technology Department, University of Granada, 18071 Granada, Spain
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Tejada-Casado M, Ghinea R, Martínez-Domingo MÁ, Pérez MM, Cardona JC, Ruiz-López J, Herrera LJ. Validation of a Hyperspectral Imaging System for Color Measurement of In-Vivo Dental Structures. Micromachines (Basel) 2022; 13:1929. [PMID: 36363950 PMCID: PMC9697747 DOI: 10.3390/mi13111929] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/02/2022] [Accepted: 11/05/2022] [Indexed: 06/16/2023]
Abstract
A full comprehension of colorimetric relationships within and between teeth is key for aesthetic success of a dental restoration. In this sense, hyperspectral imaging can provide point-wise reliable measurements of the tooth surface, which can serve for this purpose. The aim of this study was to use a hyperspectral imaging system for the colorimetric characterization of 4 in-vivo maxillary anterior teeth and to cross-check the results with similar studies carried out with other measuring systems in order to validate the proposed capturing protocol. Hyperspectral reflectance images (Specim IQ), of the upper central (UCI) and lateral incisors (ULI), were captured on 30 participants. CIE-L*a*b* values were calculated for the incisal (I), middle (M) and cervical (C) third of each target tooth. ΔEab* and ΔE00 total color differences were computed between different tooth areas and adjacent teeth, and evaluated according to the perceptibility (PT) and acceptability (AT) thresholds for dentistry. Non-perceptible color differences were found between UCIs and ULIs. Mean color differences between UCI and ULI exceeded AT (ΔEab* = 7.39-7.42; ΔE00 = 5.71-5.74) in all cases. Large chromatic variations between I, M and C areas of the same tooth were registered (ΔEab* = 5.01-6.07 and ΔE00 = 4.07-5.03; ΔEab* = 5.80-8.16 and ΔE00 = 4.37-5.15; and ΔEab* = 5.42-5.92 and ΔE00 = 3.87-4.16 between C and M, C and I and M and I, respectively). The use of a hyperspectral camera has proven to be a reliable and effective method for color evaluation of in-vivo natural teeth.
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Affiliation(s)
- Maria Tejada-Casado
- Department of Optics, Faculty of Science, Campus Fuentenueva, Edificio Mecenas, s/n., University of Granada, ibsGranada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, Campus Fuentenueva, Edificio Mecenas, s/n., University of Granada, ibsGranada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
| | - Miguel Ángel Martínez-Domingo
- Department of Optics, Faculty of Science, Campus Fuentenueva, Edificio Mecenas, s/n., University of Granada, ibsGranada, 18071 Granada, Spain
| | - María M. Pérez
- Department of Optics, Faculty of Science, Campus Fuentenueva, Edificio Mecenas, s/n., University of Granada, ibsGranada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
| | - Juan C. Cardona
- Department of Optics, Faculty of Science, Campus Fuentenueva, Edificio Mecenas, s/n., University of Granada, ibsGranada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
| | - Javier Ruiz-López
- Department of Optics, Faculty of Science, Campus Fuentenueva, Edificio Mecenas, s/n., University of Granada, ibsGranada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
| | - Luis Javier Herrera
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
- Computer Architecture and Technology Department, University of Granada, 18071 Granada, Spain
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Carrillo-Perez F, Pecho OE, Morales JC, Paravina RD, Della Bona A, Ghinea R, Pulgar R, Pérez MDM, Herrera LJ. Applications of artificial intelligence in dentistry: A comprehensive review. J ESTHET RESTOR DENT 2021; 34:259-280. [PMID: 34842324 DOI: 10.1111/jerd.12844] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/30/2021] [Accepted: 11/09/2021] [Indexed: 12/25/2022]
Abstract
OBJECTIVE To perform a comprehensive review of the use of artificial intelligence (AI) and machine learning (ML) in dentistry, providing the community with a broad insight on the different advances that these technologies and tools have produced, paying special attention to the area of esthetic dentistry and color research. MATERIALS AND METHODS The comprehensive review was conducted in MEDLINE/PubMed, Web of Science, and Scopus databases, for papers published in English language in the last 20 years. RESULTS Out of 3871 eligible papers, 120 were included for final appraisal. Study methodologies included deep learning (DL; n = 76), fuzzy logic (FL; n = 12), and other ML techniques (n = 32), which were mainly applied to disease identification, image segmentation, image correction, and biomimetic color analysis and modeling. CONCLUSIONS The insight provided by the present work has reported outstanding results in the design of high-performance decision support systems for the aforementioned areas. The future of digital dentistry goes through the design of integrated approaches providing personalized treatments to patients. In addition, esthetic dentistry can benefit from those advances by developing models allowing a complete characterization of tooth color, enhancing the accuracy of dental restorations. CLINICAL SIGNIFICANCE The use of AI and ML has an increasing impact on the dental profession and is complementing the development of digital technologies and tools, with a wide application in treatment planning and esthetic dentistry procedures.
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Affiliation(s)
- Francisco Carrillo-Perez
- Department of Computer Architecture and Technology, E.T.S.I.I.T.-C.I.T.I.C. University of Granada, Granada, Spain
| | - Oscar E Pecho
- Post-Graduate Program in Dentistry, Dental School, University of Passo Fundo, Passo Fundo, Brazil
| | - Juan Carlos Morales
- Department of Computer Architecture and Technology, E.T.S.I.I.T.-C.I.T.I.C. University of Granada, Granada, Spain
| | - Rade D Paravina
- Department of Restorative Dentistry and Prosthodontics, School of Dentistry, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Alvaro Della Bona
- Post-Graduate Program in Dentistry, Dental School, University of Passo Fundo, Passo Fundo, Brazil
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain
| | - Rosa Pulgar
- Department of Stomatology, Campus Cartuja, University of Granada, Granada, Spain
| | - María Del Mar Pérez
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain
| | - Luis Javier Herrera
- Department of Computer Architecture and Technology, E.T.S.I.I.T.-C.I.T.I.C. University of Granada, Granada, Spain
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Pop-Ciutrila IS, Ghinea R, Dudea D, Ruiz-López J, Pérez MM, Colosi H. The effects of thickness and shade on translucency parameters of contemporary, esthetic dental ceramics. J ESTHET RESTOR DENT 2021; 33:795-806. [PMID: 33866673 DOI: 10.1111/jerd.12733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 02/20/2021] [Accepted: 04/04/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To analyze translucency variations among four different contemporary esthetic ceramic systems having different shades and thicknesses. MATERIAL AND METHODS Ceramic specimens having different shades and translucencies were tested: leucite reinforced glass-ceramic (ECAD), conventional feldspathic ceramic (Noritake), zirconia reinforced lithium silicate glass-ceramic (Suprinity) and hybrid ceramic (Enamic). Specimens of 0.6, 0.9, 1.2, 1.5 and 2.0-mm thickness (n = 3/group, 615 total) were prepared. Translucency (TP) and Relative Translucency (RTP) Parameters were calculated from spectroradiometric color readings. Effects of shade and thickness for a given system were statistically analyzed using MANOVA and Tukey post-hoc multiple comparisons tests. Translucency variations were assessed comparatively with literature-based perceptibility and acceptability thresholds. RESULTS TP/RTP values of all ceramic materials decreased with increasing thickness. The most translucent specimens were 0.6-mm thick ECAD HT-A3.5 (TP = 31.99) and ECAD HT-C2 (RTP = 23.75), while the least translucent was 2-mm thick Enamic T-3 M2 (TP = 7.27; RTP = 4.79). Thickness and material type significantly influenced translucency (p < 0.001). Noritake and ECAD LT showed similar translucency values, as well as Suprinity HT and ECAD LT. CONCLUSIONS For ceramic restorations thicker than 0.9-mm, any thickness increase of 0.3-0.5 mm produces a perceptible but clinically acceptable translucency variation. Increases in thickness larger than 0.6-mm will result in an unacceptable translucency shift. Dental practitioners need to recognize key factors that influence translucency of ceramic restorations in order to choose the optimal material, shade, translucency, and thickness suitable for different clinical scenarios. While shade plays a minor role in translucency variation, ceramic type and restoration thickness significantly affect overall translucency.
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Affiliation(s)
- Ioana Sofia Pop-Ciutrila
- Department of Conservative Dentistry and Endodontics, Faculty of Dental Medicine, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain.,Department of Physics, Faculty of Sciences, University of Craiova, Craiova, Romania
| | - Diana Dudea
- Department of Prosthodontics and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Javier Ruiz-López
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain
| | - Maria M Pérez
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain
| | - Horatiu Colosi
- Department of Medical Informatics and Biostatistics, Faculty of General Medicine, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
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Pop-Ciutrila IS, Ghinea R, Colosi HA, Ruiz-López J, Perez MM, Paravina RD, Dudea D. Color compatibility between dental structures and three different types of ceramic systems. BMC Oral Health 2021; 21:75. [PMID: 33596918 PMCID: PMC7890892 DOI: 10.1186/s12903-021-01404-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 01/21/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To assess color compatibility between dental structures (human enamel and dentine) and three different types of ceramic systems. METHODS Samples (1 and 2 mm-thick) of extracted tooth (containing dentine and enamel areas) and three ceramic systems with different shades and opacities (HT-High Translucent, T-Translucent) were prepared for this study: Vita Suprinity-VS (HT, T; A1, A2, A3, A3.5, B2, C2, D2) (Vita Zahnfabrik); Vita Enamic-VE (HT, T; 1M1, 1M2, 2M2, 3M2) (Vita Zahnfabrik) and Noritake Super Porcelain EX-3-NKT (A1, A2, A3, A3.5, B2, C2, D2) (Kuraray Noritake Dental). Reflectance measurements of all samples were performed over black backgrounds using a non-contact spectroradiometer (SpectraScan PR-670, Photo Research) under a CIE 45°/0° geometry. CIE L*a*b* color parameters were measured and CIELAB/CIEDE2000 color differences (ΔE00/ΔE*ab) and corresponding Coverage Error (CE) of ceramic system for dentine or enamel samples were calculated. Color data was analyzed using one-way ANOVA and post-hoc multiple comparisons tests. CE values were interpreted by comparisons with available 50:50% acceptability color threshold (AT) for dentistry. RESULTS Statistically significant differences in lightness were found among all ceramic systems and human dentine (p < 0.001), while no significant differences were registered between enamel and VSHT, T and VEHT. 1 mm dentine showed no statistical differences with VST and VSHT for a* coordinate, while 2 mm dentine showed no significant differences (p > 0.05) with VEHT. Thin samples (1 mm) of dentine and enamel showed significant statistical differences (p < 0.05) for b* coordinate with less translucent materials (NKT, VET and VST). For dentine samples, none of the ceramic materials provided a CE lower than AT. VSHT provided the best CE for 1 mm-thick (CE00 = 1.7, CEab = 1.9) and for 2 mm-thick (CE00 = 2.3; CEab = 2.5) enamel samples. CONCLUSIONS Color coordinates of evaluated esthetic ceramic systems were statistically different from those of human dentine in almost all cases. The evaluated ZrO2 lithium silicate glass-ceramic (VS), with its two levels of translucency, provided lower CE values with human enamel samples while conventional feldspathic ceramic (NKT) and hybrid ceramic systems (VE) demonstrated a better color compatibility with dentin samples.
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Affiliation(s)
- Ioana-Sofia Pop-Ciutrila
- Department of Conservative Dentistry and Endodontics, Faculty of Dental Medicine, Iuliu Hatieganu University of Medicine and Pharmacy, 33 Motilor Street, 400001, Cluj-Napoca, Romania
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Campus de Fuentenueva, s/n, 18071, Granada, Spain. .,Houston Center for Biomaterials and Biomimetics (HCBB), University of Texas School of Dentistry at Houston, 7500 Cambridge St., Ste. 5350, Houston, TX, USA. .,Department of Physics, Faculty of Sciences, University of Craiova, 13 AI Cuza Street, 200585, Craiova, Romania.
| | - Horatiu A Colosi
- Department of Medical Informatics and Biostatistics, Faculty of General Medicine, Iuliu Hatieganu University of Medicine and Pharmacy, 6 Louis Pasteur Street, 400349, Cluj-Napoca, Romania
| | - Javier Ruiz-López
- Department of Optics, Faculty of Science, University of Granada, Campus de Fuentenueva, s/n, 18071, Granada, Spain
| | - Maria M Perez
- Department of Optics, Faculty of Science, University of Granada, Campus de Fuentenueva, s/n, 18071, Granada, Spain.,Houston Center for Biomaterials and Biomimetics (HCBB), University of Texas School of Dentistry at Houston, 7500 Cambridge St., Ste. 5350, Houston, TX, USA
| | - Rade D Paravina
- Department of Restorative Dentistry and Prosthodontics, Houston Center for Biomaterials and Biomimetics (HCBB), University of Texas School of Dentistry at Houston, 7500 Cambridge St., Ste. 5350, Houston, TX, USA
| | - Diana Dudea
- Department of Prosthodontics and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, 32 Clinicilor Street, 400006, Cluj-Napoca, Romania
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Ruiz-López J, Pulgar R, Lucena C, Pelaez-Cruz P, Cardona JC, Perez MM, Ghinea R. Impact of short-term dental dehydration on in-vivo dental color and whiteness. J Dent 2021; 105:103560. [PMID: 33352224 DOI: 10.1016/j.jdent.2020.103560] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 12/04/2020] [Accepted: 12/10/2020] [Indexed: 10/22/2022] Open
Abstract
OBJECTIVE To determine in-vivo chromatic and whiteness changes produced by short-term dental dehydration. METHODS Spectral reflectance of 452 upper incisors (226 centrals and 226 laterals) of 113 participants were measured using a spectroradiometer at baseline and after short-term dehydration (minutes 2, 4, 6, 8 and 10). CIE L*a*b* color coordinates (L*, a*, b*, C*ab and hab) and whiteness index for dentistry (WID) were calculated. Color differences (ΔE00, ΔEab*) and whiteness differences (ΔWID) were computed and interpreted based on their respective 50:50% perceptibility (PT) and acceptability thresholds (AT). Statistical analysis was performed using the related samples Wilcoxon signed-rank test. RESULTS L* showed an increasing trend with dehydration, while a*, b*, C*ab and hab have a decreasing tendency. All chromatic coordinates showed statistically significant differences (p < 0.003) at each interval of dehydration compared with baseline, except a* for all teeth. For ΔE00 and ΔEab* values were higher than PT after 2 min of teeth dehydration and higher than AT after 6 and 8 min, respectively. The percentage of teeth exceeding corresponding PT was higher than 50% after 2 min. WID index increased with dehydration time, while whiteness differences were clinically perceptible after 4 min. Statistically significant differences were found for WID between all dehydration intervals (except 8-10 min). The percentage of teeth exceeding whiteness PT was higher than 50% after 6 min of teeth dehydration. CONCLUSIONS Short-term dental dehydration produces clinically unacceptable changes in tooth color and clinically perceptible increase in tooth whiteness level. CLINICAL SIGNIFICANCE Clinical shade matching must be done within the first two minutes of any clinical procedure that requires precise chromatic determination but implies a risk of tooth dehydration.
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Affiliation(s)
- Javier Ruiz-López
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, S/N 18071, Granada, Spain.
| | - Rosa Pulgar
- Department of Stomatology, Faculty of Dentistry, University of Granada, Campus de Cartuja S/N, Granada, 18071, Spain.
| | - Cristina Lucena
- Department of Stomatology, Faculty of Dentistry, University of Granada, Campus de Cartuja S/N, Granada, 18071, Spain.
| | - Priscilla Pelaez-Cruz
- Department of Stomatology, Faculty of Dentistry, University of Granada, Campus de Cartuja S/N, Granada, 18071, Spain.
| | - Juan C Cardona
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, S/N 18071, Granada, Spain.
| | - Maria M Perez
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, S/N 18071, Granada, Spain.
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, S/N 18071, Granada, Spain; Department of Physics, Faculty of Sciences, University of Craiova, 13 AI Cuza Street, Craiova, 200585, Romania.
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Durand LB, Ruiz-López J, Perez BG, Ionescu AM, Carrillo-Pérez F, Ghinea R, Pérez MM. Color, lightness, chroma, hue, and translucency adjustment potential of resin composites using CIEDE2000 color difference formula. J ESTHET RESTOR DENT 2020; 33:836-843. [PMID: 33283966 DOI: 10.1111/jerd.12689] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 11/09/2020] [Accepted: 11/20/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To evaluate color, lightness, chroma, hue, and translucency adjustment potential of resin composites using CIEDE2000 color difference formula. METHODS Three resin composites (Filtek Universal, Harmonize, and Omnichroma) were tested. Two types of specimens were prepared: an outer base shade with an inner hole filled with test shades and single-composite specimens of all shades. Spectrorradiometric reflectances measurements and subsequent CIELAB color coordinates and translucency parameter (TP) were performed. Color (CAP00 ), lightness, chroma, hue, and translucency (TAP00 ) adjustment potential using CIEDE2000 color difference were computed. Color and transparency differences among composite materials and shades were statistically tested (P < 0.05). RESULTS Positive CAP00 and TAP00 values were found for majority of tested materials. CAP00 values ranged from -0.14 to 0.89, with the highest values found for Omnichroma (>0.75 in all cases). TAP00 values ranged from -0.06 to 0.86 with significant translucency differences among dual and single specimens. Omnichroma exhibited the highest adjustment potential for all color dimensions studied. CONCLUSIONS Lightness, hue, chroma, and translucency adjustment potential have been introduced using CIEDE2000 color difference formula, and have shown their usefulness to evaluate blending effect in dentistry. Color coordinates and translucency adjustment potential were dependent on dental material. Omnichroma exhibited the most pronounced blending effect. CLINICAL SIGNIFICANCE Resin composites with increased color and translucency adjustment may simplify shade selection, making this process easier and less time consuming. Furthermore, these materials might facilitate challenging and complex color matching situations.
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Affiliation(s)
- Leticia B Durand
- Department of Restorative Dentistry, Federal University of Santa María, Santa María, Brazil
| | - Javier Ruiz-López
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain
| | - Bibiana G Perez
- Department of Restorative Dentistry, Federal University of Santa María, Santa María, Brazil
| | - Ana M Ionescu
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain.,Research Associate, Department of Physics, Faculty of Sciences, University of Craiova, Craiova, Romania
| | - Francisco Carrillo-Pérez
- Department of Computer Architecture and Computer Technology, E.T.S.I.I.T, University of Granada, Granada, Spain
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain.,Research Associate, Department of Physics, Faculty of Sciences, University of Craiova, Craiova, Romania
| | - María M Pérez
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain
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Ghinea R, Herrera LJ, Pérez MM, Ionescu AM, Paravina RD. Gingival shade guides: Colorimetric and spectral modeling. J ESTHET RESTOR DENT 2019; 30:E31-E38. [PMID: 29667787 DOI: 10.1111/jerd.12376] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 03/05/2018] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To design colorimetric and spectral models of gingival shade guides that adequately represent the color of human gingiva. MATERIALS AND METHODS A previously compiled database on the spectral reflectance of healthy keratinized gingiva was used for optimization. Coverage Error (CE) and Maximal Error (ME) were optimized using CIELAB and CIEDE2000 color difference formulas. A two-phase process included an FCM algorithm and a nonlinear optimization. A t test was used to compare the performance of the different numbers of clusters/tabs in gingival shade guide models (α = .05). RESULTS CIELAB CE and ME for shade guide models with 3 to 6 clusters ranged from 3.1 to 3.9 (P = .028 for 3 vs. 4; and P = .033 for 5 vs. 6 cluster/tab comparison), while the corresponding CIEDE2000 range was from 2.1 to 2.8 (P < .001 for 3 vs. 4 tabs; P < .025 for 4 vs. 5; and P = 0.029 for 5 vs. 6 tab comparisons). The percentage of data points exhibiting a CIELAB color difference lower than the acceptability threshold ranged from 48.7% to 71.4%, and from 52.9% to 82.4%. for CIEDE2000. CONCLUSIONS An increase in the number of clusters in the gingival shade guide models was associated with a decrease in coverage error (better match) to human gingiva. Gingival shade guide models with only 4 tabs provided a CIELAB and CIEDE2000 coverage error lower than the acceptability threshold for gingival color. Spectral clustering of human gingiva was determined to be valid. CIEDE2000 color difference formula outperformed the CIELAB formula in the optimization process. CLINICAL SIGNIFICANCE Providing a shade guide model with a small number of tabs and a coverage error lower than the 50:50% acceptability threshold would be an optimal solution for shade matching in dentistry. However, no actual gingival or tooth shade guide complies with this. The clustering method, with optimization of both Coverage Error and Maximal Error and spectral clustering that enables more reliable color formulation of cluster representatives of shade guide models, represents an advance when it comes to computer modeling in dentistry.
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Affiliation(s)
- Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n 18071, Granada, Spain.,Department of Restorative Dentistry and Prosthodontics, Houston Center for Biomaterials and Biomimetics (HCBB), University of Texas School of Dentistry at Houston, 7500 Cambridge St., Ste. 5350, Houston, Texas
| | - Luis Javier Herrera
- Department of Computer Architecture and Computer Technology, E.T.S.I.I.T. University of Granada, s/n 18071, Granada, Spain
| | - María M Pérez
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n 18071, Granada, Spain.,Department of Restorative Dentistry and Prosthodontics, Houston Center for Biomaterials and Biomimetics (HCBB), University of Texas School of Dentistry at Houston, 7500 Cambridge St., Ste. 5350, Houston, Texas
| | - Ana M Ionescu
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n 18071, Granada, Spain
| | - Rade D Paravina
- Department of Restorative Dentistry and Prosthodontics, Houston Center for Biomaterials and Biomimetics (HCBB), University of Texas School of Dentistry at Houston, 7500 Cambridge St., Ste. 5350, Houston, Texas
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Della Bona A, Pecho OE, Ghinea R, Cardona JC, Paravina RD, Perez MM. Influence of Bleaching and Aging Procedures on Color and Whiteness of Dental Composites. Oper Dent 2019; 44:648-658. [DOI: 10.2341/18-209-l] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Bleaching can cause perceptible color changes on resin-based composite (RBC) restorations that may not be stable with aging. The objective of this study was to evaluate color stability and whiteness variations of RBCs after bleaching and aging procedures. Discs (10 mm in diameter and 1 mm thick) of shades A2 and A3 were fabricated from two RBCs (Filtek Z250 and Filtek Z350 XT) and divided into three subgroups (for each composite and shade) (n=5) as follows: control (no bleaching), at-home bleaching, and in-office bleaching. All specimens underwent an accelerated artificial aging up to 450 KJ/m2 and 900 KJ/m2 in an aging chamber (Suntest XXL+). A spectroradiometer (SpectraScan PR-670) was used to obtain CIE L*a*b* coordinates. CIEDE2000 color difference (ΔE00) and whiteness index for dentistry (WID) were used to evaluate color stability. Color and whiteness differences data were analyzed considering the 50:50% visual color difference thresholds (perceptibility [PT] and acceptability [AT]) and 50:50% whiteness thresholds (whiteness perceptibility [WPT] and whiteness acceptability [WAT]). Analysis of variance and Tukey tests (α=0.05) were used to statistically analyze the data. After bleaching, all specimens showed ΔE00 and ΔWID values below their corresponding acceptability thresholds (AT and WAT, respectively). After aging, L* and WID values decreased while b* values increased (p≤0.05), resulting in ΔE00 and ΔWID values above AT and WAT, respectively. Color changes after bleaching RBCs were clinically acceptable, while aging provoked clinically perceptible color changes.
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Affiliation(s)
- A Della Bona
- Alvaro Della Bona, DDS, MMedSci, PhD, Post-graduate Program in Dentistry, Dental School, University of Passo Fundo, Passo Fundo, Brazil
| | - OE Pecho
- Oscar E Pecho, DDS, PhD, Post-graduate Program in Dentistry, Dental School, University of Passo Fundo, Passo Fundo, Brazil
| | - R Ghinea
- Razvan Ghinea, PhD, Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Granada, Spain
| | - JC Cardona
- Juan C Cardona, PhD, Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Granada, Spain
| | - RD Paravina
- Rade D Paravina, DDS, MS, PhD, Houston Center for Biomaterials and Biomimetics, University of Texas School of Dentistry, Houston, TX
| | - MM Perez
- Maria M Perez, PhD, Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Granada, Spain
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Abstract
Background:
The final goal of color measurement or shade specification in dentistry is
the reproduction by prosthetic materials of all important appearance characteristics of natural oral
structures. The application of color science in dentistry is an objective way to measure and evaluate
such structures and dental materials in clinical practice and dental research.
Methods:
Literature on color science was reviewed to present new metrics to evaluate color differences
of dental materials and dental structures. Visual acceptability and perceptibility values of color
differences are reviewed and new whiteness indexes to describe whiteness in dentistry are presented.
Results:
In the last decade, the CIELAB 50:50% perceptibility and acceptability thresholds were set
to 1.2 and 2.7, respectively, and the CIEDE2000 50:50% perceptibility and acceptability thresholds
were set to 0.8 and 1.8. The CIEDE2000 color-difference formula became increasingly popular in
dentistry. Developments in color science have led to the description of tooth whiteness and changes
in tooth whiteness based on whiteness indexes, with the most relevant being the WID whiteness index,
which is a customized index based in CIELAB color space.
Conclusion:
The application of color science in dentistry has allowed the precise description of
tooth color and whiteness. The revised and new CIEDE2000 color-difference formula is expected to
fully replace the outdated CIELAB formula in almost all dental applications. Recent psychophysical
studies have reported values of visual thresholds and new whiteness indexes, which can serve as
quality control tools to guide the selection of esthetic dental materials, evaluate clinical performance,
and interpret visual and instrumental findings in clinical dentistry, dental research, and subsequent
standardization.
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Affiliation(s)
- María M. Pérez
- Department of Optics, Faculty of Science, Campus Fuente Nueva, Edificio Mecenas, s/n E-18071, University of Granada, Spain
| | - Oscar E. Pecho
- Department of Optics, Faculty of Science, Campus Fuente Nueva, Edificio Mecenas, s/n E-18071, University of Granada, Spain
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, Campus Fuente Nueva, Edificio Mecenas, s/n E-18071, University of Granada, Spain
| | - Rosa Pulgar
- Department of Stomatology, Faculty of Dentistry, Campus de Cartuja s/n E-18071, University of Granada, Spain
| | - Alvaro Della Bona
- Post-Graduate Program in Dentistry, Dental School, University of Passo Fundo, Campus I, Passo Fundo, RS, Brazil
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Paravina RD, Pérez MM, Ghinea R. Acceptability and perceptibility thresholds in dentistry: A comprehensive review of clinical and research applications. J ESTHET RESTOR DENT 2019; 31:103-112. [PMID: 30891913 DOI: 10.1111/jerd.12465] [Citation(s) in RCA: 212] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 02/19/2019] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The objective was to provide a literature review on perceptibility and acceptability thresholds in dentistry and corresponding recommendations. OVERVIEW A literature review on visual thresholds included findings on the judgments of the color and appearance of tooth-, gingiva- and skin-colored restorative dental materials. Discrepancies in study design contributed to inconsistencies in the research findings of some studies. These differences are related to (a) number of observers and inclusion criteria, (b) specimen number and size, (c) color measurement instrument and the setup and formulas used, (d) psychophysical experiment, (e) data processing (fitting method), and (f) % perceptibility or % acceptability values. A straightforward, consistent and practical model for the clinical and research application and interpretation of visual thresholds and recommended protocols for threshold research were provided. CONCLUSIONS Visual thresholds are of paramount importance as a quality control tool and guide the evaluation and selection of dental materials and their clinical performance. Although clinical shade matching conditions and method are rarely controlled, research on visual thresholds, especially when aiming to set standards for the profession, must be carefully planned and executed. CLINICAL SIGNIFICANCE Perceptibility and acceptability thresholds define visual match or mismatch of color, translucency, and whiteness in dentistry. Clinical and research findings cannot be fully interpreted in terms of real-life relevance without comparison with perceptibility and acceptability tolerances.
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Affiliation(s)
- Rade D Paravina
- Department of Restorative Dentistry and Prosthodontics and Houston Center for Biomaterials and Biomimetics (HCBB), University of Texas School of Dentistry at Houston, Houston, Texas
| | - Maria M Pérez
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain
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Pérez MM, Herrera LJ, Carrillo F, Pecho OE, Dudea D, Gasparik C, Ghinea R, Bona AD. Whiteness difference thresholds in dentistry. Dent Mater 2018; 35:292-297. [PMID: 30527588 DOI: 10.1016/j.dental.2018.11.022] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 11/12/2018] [Accepted: 11/15/2018] [Indexed: 10/27/2022]
Abstract
OBJECTIVE To determine the visual whiteness thresholds for esthetic dentistry using the whiteness index for dentistry based on CIELAB color space (WID). METHODS A total of 60 observers (Dentists and Laypersons; n=30) from three research sites participated in the study. A psychophysical experiment based on visual assessments of simulated images of teeth on a calibrated display was performed. Images of simulated upper central incisors (SUCI) were consecutively displayed in pairs (60) and the whiteness of each SUCI pair was compared. WID was used to calculate the visual thresholds (WPT- perceptibility threshold; and WAT- acceptability threshold) with 95% confidence intervals (CI) and a Takagi-Sugeno-Kang (TSK) Fuzzy Approximation model was used as fitting procedure. Data was statistical analyzed using paired t-test (α=0.05). RESULTS WPT and WAT were 0.72 (CI: 0.0-2.69; r2=0.52) and 2.62 (CI: 0.2-7+; r2=0.57) WID units, respectively. Significant differences (p<0.05) were found between WPT and WAT, and between dentist (WPT=0.46WID units; WAT=2.20 WID units) and layperson (WPT=0.94 WID units; WAT=2.95 WID units). SIGNIFICANCE The visual whiteness difference thresholds determined with WID index can serve as reference values for research and manufacturing of dental materials, and for clinical practice situations such as assessing the effectiveness of bleaching treatments.
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Affiliation(s)
- María M Pérez
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n 18071, Granada, Spain.
| | - Luis Javier Herrera
- Department of Computer Architecture and Computer Technology, E.T.S.I.I.T., University of Granada, s/n 18071, Granada, Spain
| | - Francisco Carrillo
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n 18071, Granada, Spain; Department of Computer Architecture and Computer Technology, E.T.S.I.I.T., University of Granada, s/n 18071, Granada, Spain
| | - Oscar E Pecho
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n 18071, Granada, Spain; Post-Graduate Program in Dentistry, Dental School, University of Passo Fundo, Campus I, Passo Fundo, RS, Brazil
| | - Diana Dudea
- Department of Prosthodontics and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, 32 Clinicilor Street, Cluj-Napoca, Romania
| | - Cristina Gasparik
- Department of Prosthodontics and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, 32 Clinicilor Street, Cluj-Napoca, Romania
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n 18071, Granada, Spain
| | - Alvaro Della Bona
- Post-Graduate Program in Dentistry, Dental School, University of Passo Fundo, Campus I, Passo Fundo, RS, Brazil
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Sarmast N, Angelov N, Ghinea R, Powers J, Paravina R. Color Compatibility of Gingival Shade Guides and Gingiva-Colored Dental Materials with Healthy Human Gingiva. INT J PERIODONT REST 2018; 38:397-403. [DOI: 10.11607/prd.3430] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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16
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Pérez MM, Ghinea R, Herrera LJ, Carrillo F, Ionescu AM, Paravina RD. Color difference thresholds for computer-simulated human Gingiva. J ESTHET RESTOR DENT 2018; 30:E24-E30. [DOI: 10.1111/jerd.12373] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- María M. Pérez
- Department of Optics, Faculty of Science; University of Granada, Campus Fuente Nueva, Edificio Mecenas; Granada s/n 18071 Spain
- Houston Center for Biomaterials and Biomimetics (HCBB) & Department of Restorative Dentistry and Prosthodontics; University of Texas School of Dentistry at Houston; Houston Texas
| | - Razvan Ghinea
- Department of Optics, Faculty of Science; University of Granada, Campus Fuente Nueva, Edificio Mecenas; Granada s/n 18071 Spain
- Houston Center for Biomaterials and Biomimetics (HCBB) & Department of Restorative Dentistry and Prosthodontics; University of Texas School of Dentistry at Houston; Houston Texas
| | - Luis Javier Herrera
- Department of Computer Architecture and Computer Technology; E.T.S.I.I.T. University of Granada; Granada s/n 18071 Spain
| | - F. Carrillo
- Department of Optics, Faculty of Science; University of Granada, Campus Fuente Nueva, Edificio Mecenas; Granada s/n 18071 Spain
- Department of Computer Architecture and Computer Technology; E.T.S.I.I.T. University of Granada; Granada s/n 18071 Spain
| | - Ana M. Ionescu
- Department of Optics, Faculty of Science; University of Granada, Campus Fuente Nueva, Edificio Mecenas; Granada s/n 18071 Spain
| | - Rade D. Paravina
- Houston Center for Biomaterials and Biomimetics (HCBB) & Department of Restorative Dentistry and Prosthodontics; University of Texas School of Dentistry at Houston; Houston Texas
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Igiel C, Lehmann KM, Ghinea R, Weyhrauch M, Hangx Y, Scheller H, Paravina RD. Reliability of visual and instrumental color matching. J ESTHET RESTOR DENT 2017; 29:303-308. [DOI: 10.1111/jerd.12321] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christopher Igiel
- Department of Prosthetic Dentistry; University Medical Center; Mainz 55131 Germany
| | - Karl Martin Lehmann
- Department of Prosthetic Dentistry; University Medical Center; Mainz 55131 Germany
| | - Razvan Ghinea
- Department of Optics; Faculty of Science, University of Granada Office 126; Granada, Granada Spain
| | - Michael Weyhrauch
- Department of Prosthetic Dentistry; University Medical Center; Mainz 55131 Germany
| | - Ysbrand Hangx
- Department of Prosthetic Dentistry; University Medical Center; Mainz 55131 Germany
| | - Herbert Scheller
- Department of Prosthetic Dentistry; University Medical Center; Mainz 55131 Germany
| | - Rade D. Paravina
- Department of Restorative Dentistry and Prosthodontics & Houston Center for Biomaterials and Biomimetics; University of Texas School of Dentistry at Houston; Houston Texas 77054
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Affiliation(s)
- Oscar E. Pecho
- Postdoctoral Researcher; Post-graduate Program in Dentistry, Dental School, University of Passo Fundo; Passo Fundo Brazil
| | - Razvan Ghinea
- Assistant Professor; Faculty of Science, Department of Optics, University of Granada; Granada Spain
| | - Maria M. Perez
- Assistant Professor; Faculty of Science, Department of Optics, University of Granada; Granada Spain
| | - Alvaro Della Bona
- Senior Professor; Post-graduate Program in Dentistry, Dental School, University of Passo Fundo; Passo Fundo Brazil
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Pecho OE, Pérez MM, Ghinea R, Della Bona A. Lightness, chroma and hue differences on visual shade matching. Dent Mater 2016; 32:1362-1373. [DOI: 10.1016/j.dental.2016.08.218] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 06/06/2016] [Accepted: 08/16/2016] [Indexed: 11/16/2022]
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Pecho OE, Ghinea R, Amaral EAND, Cardona JC, Della Bona A, Pérez MM. Relevant optical properties for direct restorative materials. Dent Mater 2016; 32:e105-12. [DOI: 10.1016/j.dental.2016.02.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 02/26/2016] [Indexed: 10/22/2022]
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21
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Pérez MDM, Ghinea R, Rivas MJ, Yebra A, Ionescu AM, Paravina RD, Herrera LJ. Development of a customized whiteness index for dentistry based on CIELAB color space. Dent Mater 2016; 32:461-7. [DOI: 10.1016/j.dental.2015.12.008] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 11/03/2015] [Accepted: 12/07/2015] [Indexed: 10/22/2022]
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Pop-Ciutrila IS, Dudea D, Eugenia Badea M, Moldovan M, Cîmpean SI, Ghinea R. Shade Correspondence, Color, and Translucency Differences between Human Dentine and a CAD/CAM Hybrid Ceramic System. J ESTHET RESTOR DENT 2016; 28 Suppl 1:S46-55. [DOI: 10.1111/jerd.12195] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Ioana-Sofia Pop-Ciutrila
- Assistant Professor, Department of Conservative Dentistry and Endodontics; Iuliu Hatieganu University of Medicine and Pharmacy; Cluj-Napoca Romania
| | - Diana Dudea
- Professor, Department of Prosthodontics and Dental Materials; Iuliu Hatieganu University of Medicine and Pharmacy; Romania
| | - Mândra Eugenia Badea
- Professor, Department of Preventive Dentistry; Iuliu Hatieganu University of Medicine and Pharmacy; Cluj-Napoca Romania
| | - Mărioara Moldovan
- Researcher in Chemistry, Department of Polymeric Composites; Raluca Ripan Institute of Research in Chemistry, Babes Bolyai University; Cluj-Napoca Romania
| | - Sanda Ileana Cîmpean
- Assistant Professor, Department of Conservative Dentistry and Endodontics; Iuliu Hat6ieganu University of Medicine and Pharmacy; Cluj-Napoca Romania
| | - Razvan Ghinea
- Assistant Professor, Department of Optics, Faculty of Science; University of Granada; Campus de Fuentenueva s/n 18071 Granada Spain
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Ho DK, Ghinea R, Herrera LJ, Angelov N, Paravina RD. Color Range and Color Distribution of Healthy Human Gingiva: a Prospective Clinical Study. Sci Rep 2015; 5:18498. [PMID: 26691598 PMCID: PMC4686981 DOI: 10.1038/srep18498] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 11/19/2015] [Indexed: 12/03/2022] Open
Abstract
The aim of this study is to compile a comprehensive database on color range and color distribution of healthy human gingiva by age, gender and ethnicity. Spectral reflection of keratinized gingiva at upper central incisors was measured by spectroradiometer and converted into CIELAB values. Lightness range (ΔL*) for all groups together was 26.8. Corresponding a* (green-red) and b* (blue-yellow) ranges (Δa* and Δb*) were 18.3 and 13.0. Significant differences (p < 0.05) were recorded by age for L* and a* coordinates, by gender for b* coordinate, and by ethnicity for L*, a* and b* coordinates. R(2)-values between color coordinates were 0.01 (L*/a*), 0.03 (L*/b*), and 0.12 (a*/b*). The smallest color differences were recorded between age groups 46-60 and 60 + (ΔE* = 0.9), and between Caucasians and Hispanics (ΔE* = 1.1). Color difference by gender was 1.3. When total L*a*b* ranges were divided into four equal segments, 51.7% of subjects had L* value within the third segment (from lightest to darkest), 47.1% had a* value within the third segment (from less red to redder), and 59.3% had b* value within the second segment (from less yellow to yellower). It was found that ethnicity and age had statistically significant influence on the color of human gingiva.
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Affiliation(s)
- Daniel K. Ho
- Department of Periodontics, School of Dentistry, University of Texas Health Science Center at Houston, Texas, USA
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Granada, Spain
| | - Luis J. Herrera
- Department of Computer, Architecture and Computer Technology, University of Granada, Granada, Spain
| | - Nikola Angelov
- Department of Periodontics, School of Dentistry, University of Texas Health Science Center at Houston, Texas, USA
| | - Rade D. Paravina
- Department of Restorative Dentistry and Prosthodontics, School of Dentistry, University of Texas Health Science Center at Houston, Texas, USA
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Affiliation(s)
- Ivan Ristic
- Department of Prosthodontics, The University of Niš School of Medicine-Section of Dentistry, Niš, Serbia
| | - Branka Trifkovic
- Department of Prosthodontics, The University of Belgrade School of Dentistry, Belgrade, Serbia
| | - Razvan Ghinea
- Department of Optics, The University of Granada Faculty of Sciences, Granada, Spain
| | - Rade D Paravina
- Department of Restorative Dentistry and Prosthodontics, The University of Texas School of Dentistry at Houston, Houston, TX, USA.,Houston Center for Biomaterials and Biomimetics (HCBB), Houston, TX, USA
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Ghinea R, Pecho O, Herrera LJ, Ionescu AM, Cardona JDLC, Sanchez MP, Paravina RD, Perez MDM. Predictive algorithms for determination of reflectance data from quantity of pigments within experimental dental resin composites. Biomed Eng Online 2015; 14 Suppl 2:S4. [PMID: 26329369 PMCID: PMC4547340 DOI: 10.1186/1475-925x-14-s2-s4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background Being able to estimate (predict) the final spectrum of reflectance of a biomaterial, especially when the final color and appearance are fundamental for their clinical success (as is the case of dental resin composites), could be a very useful tool for the industrial development of these type of materials. The main objective of this study was the development of predictive models which enable the determination of the reflectance spectrum of experimental dental resin composites based on type and quantity of pigments used in their chemical formulation. Methods 49 types of experimental dental resin composites were formulated as a mixture of organic matrix, inorganic filler, photo activator and other components in minor quantities (accelerator, inhibitor, fluorescent agent and 4 types of pigments). Spectral reflectance of all samples were measured, before and after artificial chromatic aging, using a spectroradiometer. A Multiple Nonlinear Regression Model (MNLR) was used to predict the values of the Reflectance Factors values in the visible range (380 nm-780 nm), before and after aging, from % Pigment (%P1, %P2, %P3 and %P4) within the formulation. Results The average value of the prediction error of the model was 3.46% (SD: 1.82) across all wavelengths for samples before aging and 3.54% (SD: 1.17) for samples after aging. The differences found between the predicted and measured values of the chromatic coordinates are smaller than the acceptability threshold and, in some cases, are even below the perceptibility threshold. Conclusions Within the framework of this pilot study, the nonlinear predictive models developed allow the prediction, with a high degree of accuracy, of the reflectance spectrum of the experimental dental resin composites.
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Della Bona A, Pecho OE, Ghinea R, Cardona JC, Pérez MM. Colour parameters and shade correspondence of CAD–CAM ceramic systems. J Dent 2015; 43:726-34. [DOI: 10.1016/j.jdent.2015.02.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 01/21/2015] [Accepted: 02/26/2015] [Indexed: 10/23/2022] Open
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Paravina RD, Ghinea R, Herrera LJ, Bona AD, Igiel C, Linninger M, Sakai M, Takahashi H, Tashkandi E, Mar Perez MD. Color Difference Thresholds in Dentistry. J ESTHET RESTOR DENT 2015; 27 Suppl 1:S1-9. [DOI: 10.1111/jerd.12149] [Citation(s) in RCA: 453] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Rade D. Paravina
- Department of Restorative Dentistry and Prosthodontics; School of Dentistry; University of Texas; Houston TX USA
- Houston Center for Biomaterials and Biomimetics (HCBB); Houston TX USA
| | - Razvan Ghinea
- Department of Optics; University of Granada Faculty of Sciences; Granada Spain
| | - Luis J. Herrera
- Department of Computer Architecture and Computer Technology; School of Information Technology and Telecommunications Engineering; University of Granada Higher Technical; Granada Spain
| | - Alvaro D. Bona
- School of Dentistry; University of Passo Fundo; Passo Fundo Brazil
| | - Christopher Igiel
- University Medical Center; Johannes Gutenberg University; Mainz Germany
| | - Mercedes Linninger
- Department of Prosthodontics; Semmelweis University Faculty of Dentistry; Budapest Hungary
| | - Maiko Sakai
- Department of Restorative Dentistry and Biomaterials Sciences; Harvard University School of Dental Medicine; Boston MA USA
| | - Hidekazu Takahashi
- Oral Biomaterials Engineering; Faculty of Dentistry; Tokyo Medical and Dental University; Tokyo Japan
| | - Esam Tashkandi
- Department of Prosthodontics; College of Dentistry; King Saud University; Riyadh Saudi Arabia
| | - Maria del Mar Perez
- Department of Optics; University of Granada Faculty of Sciences; Granada Spain
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Ghinea R, White I, Benjamin B, Kidron D, Shpitz B, Avital S. Laparoscopic-assisted extralevator abdominoperineal excision using a parastomal prophylactic mesh and a biological mesh for pelvic floor reconstruction. Tech Coloproctol 2015; 19:317-8. [DOI: 10.1007/s10151-015-1280-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 12/20/2014] [Indexed: 11/29/2022]
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Pecho O, Ionescu A, Ghinea R, Cardona J, Perez M, Della Bona A. Influence of microstructure on optical properties of lithium disilicate ceramics. Dent Mater 2015. [DOI: 10.1016/j.dental.2015.08.105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Pecho OE, Ghinea R, Ionescu AM, Cardona JC, Della Bona A, Pérez MDM. Optical behavior of dental zirconia and dentin analyzed by Kubelka-Munk theory. Dent Mater 2014; 31:60-7. [PMID: 25499249 DOI: 10.1016/j.dental.2014.11.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 11/13/2014] [Accepted: 11/14/2014] [Indexed: 12/30/2022]
Abstract
OBJECTIVES To use the Kubelka-Munk theory to evaluate the scattering (S), absorption (K) and transmittance (T) of non-colored and colored dental zirconia systems and human (HD) and bovine (BD) dentins. METHODS Two zirconia systems were used: ZC- ZirCAD (Ivoclar Vivadent) and LV-LAVA (3M ESPE). Specimens from each ceramic system were divided into 3 groups (n=5): ZC1 and LV1 (non-colored); ZC2 and LV2 colored to shade A1, and ZC3 and LV3 colored to shade A3. Five human and bovine anterior teeth were flattened and polished through 1200 grit SiC paper to expose the superficial buccal dentin. All samples were prepared to a final thickness of 0.5 mm. Diffuse reflectance was measured against white and black backgrounds, using a spectroradiometer in a viewing booth with D65 illuminant and d/0° geometry. S and K coefficients and T were calculated using Kubelka-Munk's equations. Data was statistically analyzed using Kruskal-Wallis, Mann-Whitney tests, and VAF coefficient. RESULTS Spectral distributions of S, K and T were wavelength dependent. The spectral behavior of S and T was similar to HD (VAF≥96.80), even though they were statistically different (p≤0.05). The spectral behavior of K was also similar to HD, except for LV1 (VAF=38.62), yet all ceramics were statistically different from HD (p≤0.05). HD and BD showed similar values of S and T (p>0.05). SIGNIFICANCE The dental professional should consider the optical behavior differences between the zirconia systems evaluated and the human dentin to achieve optimal esthetics in restorative dentistry.
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Affiliation(s)
- Oscar E Pecho
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva s/n, 18071 Granada, Spain; Post-graduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil
| | - Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva s/n, 18071 Granada, Spain; Houston Center for Biomaterials and Biomimetics, School of Dentistry, University of Texas, 7500 Cambridge St., Houston, TX 77054, USA
| | - Ana M Ionescu
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva s/n, 18071 Granada, Spain
| | - Juan C Cardona
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva s/n, 18071 Granada, Spain
| | - Alvaro Della Bona
- Post-graduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil
| | - María del Mar Pérez
- Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva s/n, 18071 Granada, Spain; Houston Center for Biomaterials and Biomimetics, School of Dentistry, University of Texas, 7500 Cambridge St., Houston, TX 77054, USA.
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Toledano M, Ghinea R, Cardona JC, Cabello I, Yamauti M, Pérez MM, Osorio R. Digital image analysis method to assess the performance of conventional and self-limiting concepts in dentine caries removal. J Dent 2013; 41 Suppl 3:e31-8. [PMID: 23507398 DOI: 10.1016/j.jdent.2013.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 02/27/2013] [Accepted: 03/01/2013] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE To assess dentine caries removal effectiveness (CRE) and minimal invasiveness potential (MIP) of carbide and polymer burs. METHODS Sectioned carious molars were photographed. Digital images were taken, before and after caries removal, using a Digital Single Lens Reflex camera. The following regions of interest were measured using visual criteria: Residual Infected Dentine (RI), Residual Affected Dentine (RA), Removal Sound Dentine (RA), Prepared Cavity (PC) and Removed Sound Dentine (RS). CRE was determined on basis of: relative residual infected dentine (RI/II), relative residual carious-affected dentine (RA/IA) and total relative residual dentine (RI+RA/II-IA). MIP was determined on basis of: infected dentine cavity size (PC/II), total relative cavity size (PC/II+IA), and corrected relative cavity size (PC-RS/II+IA). RESULTS The polymer bur showed the highest preservation of carious-affected dentine after excavation, when the RA/IA ratio was studied. Both kind of burs showed similar values after assessing the RI/II and RI+RA/II-IA ratios. The infected dentine relative cavity size (PC/II) was higher when the carbide bur was used. Both burs attained similar PC/II+IA and PC-RS/II+IA ratios. CONCLUSIONS Polymer burs accomplished the concept of minimal-invasive dentistry, showing its self-limiting ability. The minimal-invasiveness potential showed that carbide burs resulted in the worst compromise between effective and selective infected-caries removal.
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Affiliation(s)
- Manuel Toledano
- University of Granada, School of Dentistry, Dental Materials, Campus de Cartuja, s/n, 18071 Granada, Spain.
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Pecho OE, Ghinea R, Ionescu AM, Cardona JDLC, Paravina RD, Pérez MDM. Color and translucency of zirconia ceramics, human dentine and bovine dentine. J Dent 2012; 40 Suppl 2:e34-40. [DOI: 10.1016/j.jdent.2012.08.018] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 08/22/2012] [Accepted: 08/25/2012] [Indexed: 10/27/2022] Open
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Perez MDM, Ghinea R, Herrera LJ, Ionescu AM, Pomares H, Pulgar R, Paravina RD. Dental ceramics: A CIEDE2000 acceptability thresholds for lightness, chroma and hue differences. J Dent 2011; 39 Suppl 3:e37-44. [DOI: 10.1016/j.jdent.2011.09.007] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 09/12/2011] [Accepted: 09/18/2011] [Indexed: 11/16/2022] Open
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Ghinea R, Ugarte-Alvan L, Yebra A, Pecho OE, Paravina RD, Perez MDM. Influence of surface roughness on the color of dental-resin composites. J Zhejiang Univ Sci B 2011; 12:552-62. [PMID: 21726062 DOI: 10.1631/jzus.b1000374] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study deals with the influence of surface roughness on the color of resin composites. Ten resin composites (microfilled, hybrid, and microhybrid) were each polished with 500-grit, 1200-grit, 2000-grit, and 4000-grit SiC papers. The roughness parameter (R(a)) was measured using a Plμ confocal microscope, and field-emission scanning electron microscope (Fe-SEM) images were used to investigate filler morphology. Color was measured using a spectroradiometer and a D65 standard illuminant (geometry diffuse/0° specular component excluded (SCE) mode). Surface roughness decreased with grit number and was not influenced by filler size or size distribution. A significant influence of R(a) on lightness (L*) was found. Lightness increased with decreases in roughness, except for specimens that underwent polishing procedure 4 (PP4; 500-grit, 1200-grit, 2000-grit, and 4000-grit SiC papers consecutively). Generally, it was found that surface roughness influenced the color of resin composites. The composites that underwent PP1 (500-grit SiC paper) exhibited significant differences in chroma (C*), hue (h°), and lightness (L*) compared to composites that underwent PP3 (500-grit, 1200-grit, and 2000-grit SiC papers consecutively) and PP4. Color difference (∆E*) between the polishing procedures was within acceptability thresholds in dentistry.
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Affiliation(s)
- Razvan Ghinea
- Department of Optics, Faculty of Science, University of Granada, Campus Fuentenueva s/n 18071, Granada, Spain
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Ionescu AM, Alaminos M, de la Cruz Cardona J, de Dios García-López Durán J, González-Andrades M, Ghinea R, Campos A, Hita E, del Mar Pérez M. Investigating a novel nanostructured fibrin-agarose biomaterial for human cornea tissue engineering: rheological properties. J Mech Behav Biomed Mater 2011; 4:1963-73. [PMID: 22098895 DOI: 10.1016/j.jmbbm.2011.06.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 06/15/2011] [Accepted: 06/21/2011] [Indexed: 12/01/2022]
Abstract
In this work, the rheological properties of the biomaterial fibrin with different agarose concentrations, used for the generation of a bioengineered human corneal stroma by tissue engineering, before and after using a nanostructuring technique, were analyzed. The transparency of these artificial human stromas was also investigated. The temporal evaluation of the properties of these biomaterials is essential for the design of functional biological human corneal replacements. The nanostructuring technique used for the generation of nanostructured corneal constructs (NCCs) had a major influence on the rheological properties of the fibrin-agarose corneal equivalents. For an oscillatory shear stress of 1 Hz, well in the order of the natural oscillations of the human cornea, the NCCs had viscoelasticity values higher than those of non-nanostructured corneal constructs (N-NCCs), but similar to those of an ex vivo native cornea. The model that most resembled the rheological behavior of the native cornea was a fibrin-0.1% agarose concentration nanostructured construct. In addition, this artificial cornea model displayed optimal levels of transparency, similar to the native tissue. All these properties indicate that the fibrin-0.1% agarose concentration nanostructured construct might serve as an adequate candidate for the generation of an artificial complete cornea, not only for transplanting use but also for conducting pharmaceutical testing and biomedical research.
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Affiliation(s)
- Ana-Maria Ionescu
- Department of Optics, Faculty of Science, University of Granada, Campus Fuentenueva S/N, Granada, 18071, Spain
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Ghinea R, Pérez MM, Herrera LJ, Rivas MJ, Yebra A, Paravina RD. Color difference thresholds in dental ceramics. J Dent 2010; 38 Suppl 2:e57-64. [DOI: 10.1016/j.jdent.2010.07.008] [Citation(s) in RCA: 258] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 07/17/2010] [Accepted: 07/19/2010] [Indexed: 11/17/2022] Open
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