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Juntavee N, Juntavee A, Jaralpong C. Color Characteristics of High Yttrium Oxide-Doped Monochrome and Multilayer Partially Stabilized Zirconia upon Different Sintering Parameters. Eur J Dent 2024. [PMID: 38942053 DOI: 10.1055/s-0044-1787700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2024] Open
Abstract
OBJECTIVES Sintering influences the optical properties of zirconia. This study examined the effect of altering sintering temperature and time of monochrome (Mo) and multilayer (Mu) 5 mol% yttria-partially stabilized zirconia (5Y-PSZ) on color characteristics. MATERIALS AND METHODS Three hundred specimens (width × length × thickness = 10 × 20 × 2 mm) were prepared from Mo and Mu (with cervical [C], middle [M], and incisal [I] region) 5Y-PSZ and randomly sintered at decreasing (Td: 1,450°C), regular (Tr: 1,500°C), and increasing (TI: 1,550°C) sintering temperature, with extremely short (He: 10 minutes), ultrashort (Hu: 15 minutes), short (Hs: 30 minutes), and regular (Hr: 135 minutes) sintering time (n = 15/group). Color appearance (EW ), translucency parameter (TP), contrast ratio (CR), opalescence parameter (OP), and color appearance difference (∆E diff) were evaluated in the CIE L*a*b* system. Microstructures were evaluated by scanning electron microscope (SEM) and X-ray diffractometer (XRD). STATISTICAL ANALYSIS Analysis of variance (ANOVA) and Bonferroni comparisons were determined for significant differences (p < 0.05). RESULTS Significant differences in color parameters upon zirconia type, sintering temperature, and sintering time, and their interactions were indicated (p < 0.05). Increasing sintering temperature and extended sintered time resulted in larger grain, reduced tetragonal-to-monoclinic phase transformation, and significantly increased the TP and OP, but decreased the CR and ∆E diff (p < 0.05). Decreasing sintering temperature and time led to clinically unacceptable color appearance. CONCLUSION Mo was found to be more translucent than Mu. To achieve the most favorable optical properties, increasing sintering temperature and extending sintering time are recommended. Decreasing sintering temperature is not suggested. However, shortened sintering time is feasible, but it needs sintering with increasing sintering temperature to achieve a promising color appearance.
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Affiliation(s)
- Niwut Juntavee
- Department of Prosthodontics, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Apa Juntavee
- Department of Preventive Dentistry, Division of Pediatric Dentistry, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Chutikarn Jaralpong
- Division of Biomaterials and Prosthodontics Research, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
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Zhou Y, Fu L, Zhang Z, Tang X. Effect of tooth color on the accuracy of intraoral complete arch scanning under different light conditions using a zirconia restoration model. J Prosthet Dent 2024; 131:145.e1-145.e8. [PMID: 37923645 DOI: 10.1016/j.prosdent.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 10/02/2023] [Accepted: 10/03/2023] [Indexed: 11/07/2023]
Abstract
STATEMENT OF PROBLEM Information regarding the effect of tooth color under different light conditions on the accuracy of intraoral complete arch scanning is limited. PURPOSE The purpose of this in vitro study was to evaluate the effect of color and ambient light conditions on the accuracy of mandibular complete arch scanning with an intraoral scanner (IOS) using a zirconia restoration model with different shades. MATERIAL AND METHODS Five mandible dentition models with zirconia restorations of different shades were fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM). The spectral reflectance and transmittance curves were collected with a spectrophotometer to determine color parameters (Rb, T, S+A, L*, a*, b*, C*, and h). Under 4 different lighting conditions: no light (ZL), natural light (NL), room light (RL), and chair light (CL), each model was scanned 10 times by using an IOS (TRIOS 3). Three-dimensional (3D) deviation analysis and a linear deviation analysis were performed for an accurate quantitative measurement of intraoral scanning. The multivariate test was used to determine significant differences in 3D deviation and linear deviation among groups. The multiple linear regression test was conducted to investigate the relevant independent factors of mean absolute 3D deviation. RESULTS The 3D deviation analysis showed that the mean absolute 3D deviation of 3M2 model scanning was the lowest (P<.001). Moreover, under CL and RL, the accuracy results from the 3M2 model scan were demonstrated as significantly better than the tested scans under other light conditions (P=.021). The result of the linear deviation analysis indicated that the variation in distance was only significant between the bilateral canines (P=.032). Ambient light conditions, C*, and h were factors influencing mean absolute 3D deviation (R2=0.593, P<.001). CONCLUSIONS Color change influenced the accuracy of intraoral mandibular complete arch scanning under different light conditions. This effect may be attributable to the interaction between the ambient light condition and color parameters such as C* and h.
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Affiliation(s)
- Yong Zhou
- Associate Professor, Department of Dental Implantology, College & Hospital of Stomatology, Anhui Medical University, Key Laboratory of Oral Diseases Research, Hefei, Anhui, PR China
| | - Lijuan Fu
- Graduate student, College & Hospital of Stomatology, Anhui Medical University, Key Laboratory of Oral Diseases Research, Hefei, Anhui, PR China
| | - Zhoujing Zhang
- Graduate student, College & Hospital of Stomatology, Anhui Medical University, Key Laboratory of Oral Diseases Research, Hefei, Anhui, PR China
| | - Xuyan Tang
- Associate Professor, Department of Prosthodontics, College & Hospital of Stomatology, Anhui Medical University, Key Laboratory of Oral Diseases Research, Hefei, Anhui, PR China..
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Liu H, Inokoshi M, Xu K, Tonprasong W, Minakuchi S, Van Meerbeek B, Vleugels J, Zhang F. Does speed-sintering affect the optical and mechanical properties of yttria-stabilized zirconia? A systematic review and meta-analysis of in-vitro studies. JAPANESE DENTAL SCIENCE REVIEW 2023; 59:312-328. [PMID: 37705876 PMCID: PMC10495607 DOI: 10.1016/j.jdsr.2023.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 08/02/2023] [Accepted: 08/22/2023] [Indexed: 09/15/2023] Open
Abstract
Zirconia restorations are increasingly popular in dental treatment. Yttria-stabilized zirconia (YSZ) needs to be sintered for clinical applications and novel speed-sintering protocols are being developed for chairside treatments. Whether the properties of speed-sintered YSZ meet clinical requirements, however, remains unclear. Therefore, we conducted a systematic review and meta-analysis on the influence of speed-sintering on the optical and mechanical properties of dental YSZ according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. A literature search was conducted using PubMed, Embase, and Web of Science databases for relevant articles published between January 1, 2010 and February 28, 2022 in English, Chinese, or Japanese. After full-text evaluation and quality assessment, 26 articles were selected. Meta-analysis revealed that speed-sintering does not significantly affect the CIEDE2000-based translucency parameter, contrast ratio, three-point flexural strength, biaxial flexural strength, or fracture toughness of YSZ (p < 0.01) compared to conventional sintering. However, the CIELab-based translucency parameter of conventionally sintered YSZ is higher than that of speed-sintered YSZ. The descriptive analysis indicated that speed-sintering does not affect the hardness of YSZ compared to that of conventionally sintered YSZ. The results indicate that speed-sintering is suitable for preparing YSZ for dental restorations.
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Affiliation(s)
- Hengyi Liu
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8549, Japan
| | - Masanao Inokoshi
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8549, Japan
| | - Kaiqi Xu
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8549, Japan
| | - Watcharapong Tonprasong
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8549, Japan
| | - Shunsuke Minakuchi
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8549, Japan
| | - Bart Van Meerbeek
- KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & UZ Leuven (University Hospitals Leuven), Dentistry, Kapucijnenvoer 7 blok a, B-3000 Leuven, Belgium
| | - Jef Vleugels
- KU Leuven (University of Leuven), Department of Materials Engineering, Kasteelpark Arenberg 44, BE-3001 Leuven, Belgium
| | - Fei Zhang
- KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & UZ Leuven (University Hospitals Leuven), Dentistry, Kapucijnenvoer 7 blok a, B-3000 Leuven, Belgium
- KU Leuven (University of Leuven), Department of Materials Engineering, Kasteelpark Arenberg 44, BE-3001 Leuven, Belgium
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Shin HJ, Kwon YH, Seol HJ. Effect of superspeed sintering on translucency, opalescence, microstructure, and phase fraction of multilayered 4 mol% yttria-stabilized tetragonal zirconia polycrystal and 6 mol% yttria-stabilized partially stabilized zirconia ceramics. J Prosthet Dent 2023; 130:254.e1-254.e10. [PMID: 37357086 DOI: 10.1016/j.prosdent.2023.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 06/27/2023]
Abstract
STATEMENT OF PROBLEM The optical properties of recently developed multilayer zirconia have mainly been studied for the effects of conventional sintering and speed sintering but not as much for the effect of superspeed sintering. As superspeed sintering protocols typically require a higher sintering temperature and higher heating and cooling rates than speed- and conventional sintering protocols, the optical properties of superspeed sintered zirconia may be affected differently. PURPOSE The purpose of this in vitro study was to investigate the effect of superspeed sintering on the optical properties, microstructure, and phase fraction of multilayered 4 mol% yttria-stabilized (4Y-) and 6 mol% yttria-stabilized (6Y-) zirconia. MATERIAL AND METHODS Multilayered 4Y- and 6Y-zirconia were sectioned. After conventional and superspeed sintering, the translucency parameter (TP), and opalescence parameter (OP) were measured with a spectrophotometer (n=10). To obtain the grain sizes from the field emission scanning electron microscopy (FE-SEM) images for each layer (n=2), more than 500 (6Y-zirconia) and 800 grains (4Y-zirconia) were measured by linear intercept methods. The phase fractions were obtained through X-ray diffraction (XRD) analysis by using the Rietveld method (n=1). The results were analyzed by 3-way ANOVA and post hoc Tukey honest significant difference tests (TP and OP) and by 3-way ANOVA and post hoc Scheffé tests (grain size) (α=.05). RESULTS No layers exhibited a significant difference in TP after superspeed sintering, except the dentin layer (DL) and transition layer 2 (T2) of 4Y- and 6Y-zirconia, respectively. The TP increased (P<.05) in DL for superspeed sintered 4Y-zirconia and decreased (P<.05) in T2 for the superspeed sintered 6Y-zirconia. However, the difference in TP by superspeed sintering was lower than the perceptibility thresholds of 50:50%. The OP decreased (P<.05) in the DL and T2 of 4Y-zirconia after superspeed sintering. For 6Y-zirconia, the OP decreased (P<.05) in all layers except for the transition layer 1 (T1) after superspeed sintering. However, the difference in OP values was minimal, with only a 1.1 difference observed for Zolid Gen-X (4Y) and a range of 1.22 to 1.62 for Katana UTML (6Y) when using superspeed sintering. No significant change was found in the grain size after superspeed sintering of either zirconia. Regardless of the sintering speed, the average grain size of the 6Y-zirconia (conventional: 2.09 to 2.21 μm; superspeed: 2.11 to 2.20 μm) was larger than that of the 4Y-zirconia (conventional: 0.50 to 0.52 μm; superspeed: 0.52 to 0.54 μm). Owing to superspeed sintering, the metastable tetragonal (T') phase content increased while the tetragonal (T) phase decreased in 4Y-zirconia; in 6Y-zirconia, the cubic (C) phase content increased, while the T'-phase content decreased. CONCLUSIONS Superspeed sintering did not result in any clinically significant changes in the translucency and opalescence of 4Y- or 6Y-zirconia.
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Affiliation(s)
- Hye-Jeong Shin
- Post-Doctoral Researcher, Department of Dental Materials, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, Gyeongsangnam-do, Republic of Korea
| | - Yong-Hoon Kwon
- Professor, Department of Dental Materials, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, Gyeongsangnam-do, Republic of Korea
| | - Hyo-Joung Seol
- Professor, Department of Dental Materials, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, Gyeongsangnam-do, Republic of Korea.
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Albayrak H, Eraslan R, Aydinlioglu Ö. Effect of sintering procedures on optical properties, chemical composition, and grain size of monolithic zirconia ceramic at different thicknesses after hydrothermal aging: An in vitro study. J Indian Prosthodont Soc 2023; 23:57-64. [PMID: 36588376 PMCID: PMC10088447 DOI: 10.4103/jips.jips_345_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 10/09/2022] [Accepted: 11/21/2022] [Indexed: 12/29/2022] Open
Abstract
Aim The purpose of the present study was to examine the optical properties, chemical composition, and grain size (GS) of monolithic zirconia (MZ) ceramic at different thicknesses sintered using different procedures after hydrothermal aging. Settings and Design An in vitro study. Materials and Methods Forty MZ discs (0.5-mm thickness [Group-0.5] and 1-mm thickness [Group-1]; 12 mm diameter) were milled and divided according to standard (Group-ST) and speed (Group-SP) sintering procedures. All specimens were hydrothermally aged at 134°C after sintering. Translucency (TP), opalescence (OP), and fluorescence (ΔEabFNx01-FL) parameters were calculated using the color coordinates (LFNx01, aFNx01, bFNx01, respectively) of the discs. The chemical composition and the GS of the specimens were characterized using X-ray fluorescence spectroscopy and a scanning electron microscopy, respectively. Statistical Analysis Used TPs and ΔEabFNx01-FLs were analyzed using independent samples t-tests and Mann-Whitney U-tests while a two-way analysis of variance (ANOVA) was used for OPs. Results Group-1 showed significantly lower TP than Group-0.5 (P < 0.001) but a significantly higher OP (P = 0.014). Group-SP showed significantly higher OP (P = 0.00003) and ΔEabFNx01-FL (P = 0.0026) values than Group-ST without considering the thickness. Group-SP (0.29 ± 0.119 μm) had a smaller GS than Group-ST (0.306 ± 0.142 μm). Compared to Group-ST, Group-SP had a lower percentage of Y2O3 and a higher percentage of Al2O3. Conclusion The effect of the sintering procedure on TP and OP of MZ was not perceived by the naked eye. The speed sintering procedure may increase Δ EFNx01ab-FL of MZ to higher values than natural teeth when compared with standard sintering. The speed sintering may cause minor changes in GS and the chemical composition of MZ.
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Affiliation(s)
- Haydar Albayrak
- Department of Prosthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey
| | - Ravza Eraslan
- Department of Prosthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey
| | - Ömer Aydinlioglu
- Department of Textile Engineering, Erciyes University, Kayseri, Turkey
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Cho MH, Seol HJ. Optical Properties, Microstructure, and Phase Fraction of Multi-Layered Monolithic Zirconia with and without Yttria-Gradient. MATERIALS (BASEL, SWITZERLAND) 2022; 16:41. [PMID: 36614380 PMCID: PMC9821384 DOI: 10.3390/ma16010041] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/12/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
The differences in the optical properties of multi-layered zirconia with and without yttria-gradient are not fully understood. This study aimed to evaluate and compare the optical properties, related microstructures, and phase fractions of multi-layered zirconia with and without yttria-gradient. For this, multi-layered zirconia of 5 mol% yttria (5Y) stabilized (Katana STML) and 4Y/5Y stabilized (e.max MT Multi) were cut layerwise, sintered, and analyzed using the opalescence parameter (OP), average transmittance (AT%), translucency parameter (TP), and contrast ratio (CR). The average grain size and phase fractions were obtained from field-emission scanning electron micrographs and X-ray diffraction patterns, respectively. Although the TP values of Katana STML and e.max MT Multi did not show a significant difference (except for transition layer 1), the results of AT and CR showed that the translucency of e.max MT Multi was slightly higher than that of Katana STML (p < 0.05). The opalescence gradient was higher in Katana STML than in the e.max MT Multi. In both zirconia types, translucency increased from the dentin to enamel layer based on the AT, TP, and CR results, while OP decreased (p < 0.05). The higher translucency from the dentin to enamel layer in Katana STML was caused by the pigmentation gradient, while in e.max MT Multi, it was caused by the difference in phase fraction and the pigmentation gradient.
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Affiliation(s)
- Mi-Hyang Cho
- Department of Dental Lab, Wonkwang Health Science University, Iksan-si 54538, Republic of Korea
| | - Hyo-Joung Seol
- Department of Dental Materials, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan-si 50612, Republic of Korea
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Jeong JI, Shin HJ, Kwon YH, Seol HJ. Effect of Cooling Rate on Mechanical Properties, Translucency, Opalescence, and Light Transmission Properties of Monolithic 4Y-TZP during Glazing. MATERIALS 2022; 15:ma15124357. [PMID: 35744423 PMCID: PMC9228759 DOI: 10.3390/ma15124357] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/10/2022] [Accepted: 06/17/2022] [Indexed: 11/16/2022]
Abstract
A standard cooling rate has not been established for glazing; therefore, the effects of the cooling rate on the properties of zirconia need to be evaluated to predict outcomes in clinical practice. 4Y-TZP glazed at three different cooling rates was analyzed to estimate the effect of cooling rate during glazing on the mechanical and optical properties. Hardness tests, field-emission scanning electron microscopy analysis, X-ray diffraction analysis, flexural strength measurement, and optical property evaluations were performed. When 4Y-TZP was glazed at a higher cooling rate (Cooling-1) than the normal cooling rate (Cooling-2), there was no significant difference in grain size, flexural strength, average transmittance, and translucency parameters. The hardness was slightly reduced. The opalescence parameter was reduced for the 2.03 mm thick specimens. When 4Y-TZP was glazed at a lower cooling rate (Cooling-3) than the normal cooling rate, there was no significant difference in hardness, grain size, flexural strength, and translucency parameters. In addition, the average transmittance and opalescence parameters were slightly reduced for the 0.52 and 2.03 mm specimens, respectively. The effects of the cooling rate during glazing on the mechanical and optical properties of 4Y-TZP appear to be minimal and clinically insignificant. Therefore, even if the cooling rate cannot be strictly controlled during glazing, the clinical outcomes will not be significantly affected.
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Effect of Optical Properties of Lithium Disilicate Glass Ceramics and Light-Curing Protocols on the Curing Performance of Resin Cement. COATINGS 2022. [DOI: 10.3390/coatings12060715] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study aimed to investigate the effects of optical properties of lithium disilicate glass ceramics and the light-curing protocols (LCP) on the curing performance of light-cured resin cement. Lithium disilicate glass-ceramics with different optical properties were sectioned to produce ceramic specimens of 0.8 mm thickness. Irradiance through the ceramic specimens was measured by a radiometer. Light transmittance of ceramics was assessed using a UV/Vis spectrophotometer. The light-cured resin cement was injected into a Teflon mold and ceramics with different optical properties were placed on it, cured under different LCPs, and the degree of conversion (DC) and Vickers microhardness of the resin cement were separately measured by Micro-ATR/FTIR spectrometry and the microhardness tester. The shade (p < 0.001) and transparency (p < 0.001) of ceramics affect the irradiance of the light-curing unit. The transparency (p < 0.001) of the ceramic and light-curing protocols (p < 0.001) affect the DC and microhardness of resin cements. When the thickness of the ceramic is 0.8 mm, the light transmittance of the ceramic and the curing performance of the resin cement increase with the increase of the transparency of the ceramic. An appropriate increase in irradiance and exposure time can optimize the curing performance of resin cement. These factors should be taken into account by the clinician when designing the bonding solution for porcelain veneers.
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Cho MH, Seol HJ. Effect of Cooling Rate during Glazing on the Mechanical and Optical Properties of Monolithic Zirconia with 3 mol% Yttria Content. MATERIALS (BASEL, SWITZERLAND) 2021; 14:7474. [PMID: 34885629 PMCID: PMC8658760 DOI: 10.3390/ma14237474] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 11/17/2022]
Abstract
Glazing is the final heat treatment process in the manufacturing of a monolithic zirconia prosthesis. Herein, the effect of cooling rate during zirconia glazing was investigated. A 3 mol% yttria-stabilized tetragonal zirconia polycrystal was glazed at the general cooling rate suggested by the manufacturer, as well as at higher and lower cooling rates, and the differences in flexural strength, hardness, optical properties, and crystal structure were evaluated. A higher cooling rate did not affect the flexural strength, hardness, grain size, optical properties, or crystal structure; however, the Weibull modulus decreased by 1.3. A lower cooling rate did not affect the flexural strength, optical properties, or crystal structure; however, the Weibull characteristic strength increased by 26.7 MPa and the Weibull modulus increased by 0.9. The decrease in hardness and the increase in grain size were statistically significant; however, the numerical differences were negligible. This study revealed that a lower cooling rate provides more reliable flexural strength. Therefore, glazing can proceed at a general cooling rate, which takes 3-4 min; however, glazing at a lower cooling rate will provide a more consistent flexural strength if desired, despite being time-consuming.
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Affiliation(s)
- Mi-Hyang Cho
- Department of Dental Lab, Wonkwang Health Science University, Iksan-si 54538, Jeonbuk-do, Korea;
| | - Hyo-Joung Seol
- Department of Dental Materials, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan-si 50612, Gyeongsangnam-do, Korea
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Effect of Veneering and Hydrothermal Aging on the Translucency of Newly Introduced Extra Translucent and High Translucent Zirconia with Different Thicknesses. BIOMED RESEARCH INTERNATIONAL 2021; 2021:7011021. [PMID: 34722770 PMCID: PMC8553453 DOI: 10.1155/2021/7011021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/25/2021] [Accepted: 10/04/2021] [Indexed: 11/17/2022]
Abstract
Purpose The purpose of this study was to evaluate the effect of veneering and aging on the translucency of newly introduced extra and high translucent zirconia with different thickness. Materials and Methods One hundred forty disk-shaped specimens were fabricated from two translucent zirconia blocks (VITA YZ XT and VITA YZ HT), and they are milled with CAD/CAM system. Then, specimens were divided into nonveneered (XT, HT) and veneered groups (XTV, HTV). Nonveneered groups were prepared with four different thicknesses (0.5-1-1.5-2 mm). Veneered groups were divided into three subgroups (n = 10) for veneering with base dentin ceramic with thicknesses of 0.5 + 0.5, 0.5 + 1, and 0.5 + 1.5 mm. A spectrophotometer was used to calculate the translucency parameter (TP) and contrast ratio (CR) of all specimens before and after aging. Statistical analysis was performed using 3-way ANOVA and Tukey HSD tests (p < 0.05). Results TP values were significantly affected by thickness of specimens (p < 0.001). VITA YZ XT was significantly found more translucent than VITA YZ HT. The highest translucency was observed in the XT-0.5 mm group. There is no significant difference between translucency of the veneered and nonveneered groups in the same thickness for XT. On the contrary, veneering significantly affected translucency of HT. TP values significantly decreased after aging for all groups. After aging, translucency value difference before and after aging was the highest in the XT-0.5 mm group whereas the HTV-2 mm group showed the lowest difference after aging. TP decreased significantly as thickness of specimen increases regardless of the material type. Extra translucent and nonveneered zirconia groups are more prone to hydrothermal aging. Conclusions The translucency parameter of zirconia ceramics was significantly influenced by both material type and veneering. Also, extra translucent and nonveneered zirconia groups are more susceptible to hydrothermal aging.
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Ziyad TA, Abu-Naba'a LA, Almohammed SN. Optical properties of CAD-CAM monolithic systems compared: three multi-layered zirconia and one lithium disilicate system. Heliyon 2021; 7:e08151. [PMID: 34712853 PMCID: PMC8529506 DOI: 10.1016/j.heliyon.2021.e08151] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 08/03/2021] [Accepted: 10/06/2021] [Indexed: 02/04/2023] Open
Abstract
Objective this in vitro investigation aims to evaluate and compare optical properties of three types of esthetic CAD-CAM monolithic multi-layered zirconia materials with a control (conventional lithium disilicate, IPS e. max CAD). Methods Four monolithic CAD-CAM ceramic materials were investigated: Ceramill Zolid® FX Multilayer (ZF), IPS e. max® ZirCAD MT Multi (ZM), Katana® STML (KS) and one lithium disilicate glass-ceramics as a control (IPS e. max® CAD LT; LC). A total of 72 (15 × 15 × 1 mm) samples were CAD CAM fabricated and sintered based on sample-size power calculations, and each material comprised 18 samples. The translucency and opalescence parameters with the contrast ratio were evaluated with a dental spectrophotometer over the backgrounds of black and white. The data were analyzed by ANOVA, then Bonferroni post hoc comparison test was made between groups. The statistical significance was set at p < 0.05. Results Zirconia materials revealed lower optical properties than the lithium disilicate control LC (P < 0.05). TP values ranged from 14.174 to 20.439. No differences were detected between the zirconia products in terms of TP and CR (P = 1.000). OP values ranged from 5.068 to 10.097. The lowest OP values were found statistically significant for ZF followed by KS and ZM (P = 1.000). LC had the highest TP and OP values, as well as the lowest CR (p < 0.05). Conclusions The optical properties of monolithic zirconia systems tested here are still lower than those of lithium disilicate glass-ceramics. The only difference observed between the monolithic CAD CAM zirconia materials, was for the low opalescence parameter for the ZF. Clinical significance Multi-layered monolithic zirconia systems have better esthetics by shade layers resembling natural tooth color gradients. CAD-CAM technology allowed for in-office milling and shaping of restorations using these systems. This study reports on their optical properties affecting human vision/perception of natural tooth shade to conclude about their use in the esthetic zones.
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Affiliation(s)
- Tareq A Ziyad
- PROSTHODONTICS Program, Department of Prosthodontics, Faculty of Dentistry, Jordan University of Science and Technology, Irbid, Jordan
| | - Layla A Abu-Naba'a
- Department of Prosthodontics, Jordan University of Science and Technology, Irbid, Jordan
| | - Saleh N Almohammed
- Department of Prosthodontics, Jordan University of Science and Technology, Irbid, Jordan
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Çakmak G, Donmez MB, Kashkari A, Johnston WM, Yilmaz B. Effect of thickness, cement shade, and coffee thermocycling on the optical properties of zirconia reinforced lithium silicate ceramic. J ESTHET RESTOR DENT 2021; 33:1132-1138. [PMID: 34390305 PMCID: PMC9292539 DOI: 10.1111/jerd.12808] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 07/11/2021] [Accepted: 07/28/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate the effect of thickness, cement shade, and coffee thermocycling (CTC) on the optical properties of zirconia reinforced lithium silicate (ZLS) paired with different shades of a resin cement. MATERIALS AND METHODS Thirty ZLS specimens were prepared in two different thicknesses (0.8 and 1.5 mm) and three different resin cement shades (Tr, A2, and A3) were applied (n = 5). Color determinations were done before and after 5000 CTC by using a noncontact spectroradiometer. Color change due to CTC and relative translucency parameter (RTP) before and after CTC were calculated by using CIEDE2000. Data were analyzed using ANOVA and Bonferroni-corrected t-tests(α = 0.05). RESULTS Material thickness and resin cement shade (P < 0.001) affected baseline color. Material thickness affected color difference (P = 0.025). Thickness, resin cement shade, and CTC (P ≤ 0.0001) affected RTP. The difference between the color changes of the 0.8- and 1.5-mm specimens combined with A2 shade cement after CTC was significant (P = 0.01). RTPs of all pairs decreased after CTC (P < 0.001). CONCLUSIONS Cement shade and material thickness affected the baseline color. The thickness of ZLS affected the color change after CTC only with A2 resin cement and the color change was less when the ZLS was thicker. CTC reduced the translucency of all pairs. CLINICAL SIGNIFICANCE Clinicians and patients should be aware of a potential color change after long-term coffee consumption when zirconia reinforced lithium silicate is used particularly for laminate veneers with A2 shade of the tested resin cement.
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Affiliation(s)
- Gülce Çakmak
- Buser Foundation Scholar for Implant Dentistry, Department of Reconstructive Dentistry and Gerodontology, School of Dental MedicineUniversity of BernBernSwitzerland
| | - Mustafa Borga Donmez
- Department of ProsthodonticsBiruni University Faculty of DentistryIstanbulTurkey
| | - Afnan Kashkari
- Restorative and Esthetic DentistryJohns Hopkins Aramco HealthcareDhahranSaudi Arabia
| | - William M. Johnston
- Division of Restorative and Prosthetic DentistryThe Ohio State University College of DentistryColumbusOhio
| | - Burak Yilmaz
- Department of Reconstructive Dentistry and Gerodontology, School of Dental MedicineUniversity of Bern, BernSwitzerland
- Department of Restorative, Preventive and Pediatric Dentistry, School of Dental MedicineUniversity of BernBernSwitzerland
- Division of Restorative and Prosthetic DentistryThe Ohio State UniversityOhioUSA
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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] [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] [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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Effect of fabrication techniques on the optical properties of zirconia-based systems. J Prosthet Dent 2020; 125:528.e1-528.e8. [PMID: 33280829 DOI: 10.1016/j.prosdent.2020.10.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 01/08/2023]
Abstract
STATEMENT OF PROBLEM How the optical properties of zirconia restorations are affected by their differing processing techniques is unclear. PURPOSE The purpose of this in vitro study was to evaluate the effects of 5 different fabrication techniques on the optical properties of zirconia-based systems, including the color difference between the corresponding shades (ΔE∗ab, ΔE00), translucency parameter, opalescence parameter, and fluorescence (ΔE∗ab-FL). MATERIAL AND METHODS Sixty zirconia disks (IPS e.max ZirCAD) were prepared (0.5 ±0.01mm thick) and veneered by using different techniques (n=15): Group L - layering with fluorapatite ceramic; Group P - pressing with fluorapatite ceramic; Group CB - veneered with pressing followed by layering technique; Group CO - digitally veneered with lithium disilicate glass-ceramic; and Group FZ - prepared from monolithic zirconia (inCoris TZI) (n=15). All the specimens were set to 1.5 ±0.02 mm in thickness. Color measurements were made with a spectrophotometer. Data were statistically analyzed with 1-way ANOVA and the Tukey honestly significant difference, Kruskal-Wallis, Bonferroni (α=.05), Pearson, and Spearman correlation tests (α=.01). RESULTS Significant differences were found among the groups for all the optical parameters (P<.05). All the groups showed color differences higher than the perceptibility and acceptability thresholds for ΔE∗ab and ΔE00, except the P and FZ groups that showed values lower than the acceptability threshold (ΔE∗ab<2.7). Translucency parameter, opalescence parameter, and ΔE∗ab-FL values ranged between 5.77 and 9.95, between 4.72 and 7.07, and between 1.93 and 3.14, respectively. Strong positive correlations were found between ΔE∗ab and ΔE00, as well as between translucency parameter and opalescence parameter (P<.001). CONCLUSIONS The optical properties of the zirconia-based systems were significantly affected by the fabrication techniques even when the same nominal shade was used. Therefore, the color reproduction, translucence, opalescence, and fluorescence of the selected materials should be considered for acceptable color matching.
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Effect of sintering temperature on microstructure, flexural strength, and optical properties of a fully stabilized monolithic zirconia. J Prosthet Dent 2020; 124:594-598. [DOI: 10.1016/j.prosdent.2019.08.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/04/2019] [Accepted: 08/05/2019] [Indexed: 11/23/2022]
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Valizadeh S, Mahmoudi Nahavandi A, Daryadar M, Özcan M, Hashemikamangar SS. The effect of ceramic thickness on opalescence. Clin Exp Dent Res 2020; 6:693-699. [PMID: 32902165 PMCID: PMC7745071 DOI: 10.1002/cre2.325] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 11/18/2022] Open
Abstract
Objectives Creating a tooth‐like appearance by use of dental ceramics is still a challenge. Opalescence is a unique property of dental enamel, attempted to be mimicked by dental restorative materials. This study aimed to assess the effect of ceramic thickness on opalescence. Materials and methods Twenty‐four discs were fabricated of feldspathic ceramic, IPS e.max, zirconia and Enamic ceramics with 10 mm diameter and 0.5 and 1 mm thicknesses (n = 12). The opalescence of ceramic specimens was calculated by measuring the difference in yellow‐blue axis (CIE ∆b*) and red‐green axis (CIE ∆a*) between the transmitted and reflected spectra. One‐way ANOVA was applied to compare the opalescence of different ceramic specimens with variable thicknesses at .05 level of significance. Results The opalescence of feldspathic, IPS e.max, zirconia and Enamic ceramic specimens with 0.5 mm thickness was 1.06 ± 0.15, 3.39 ± 0.15, 1.98 ± 0.15 and 1.44 ± 0.15, respectively. By increasing the thickness to 1 mm, the opalescence of feldspathic, IPS e.max, zirconia and Enamic ceramics changed to 1.12 ± 0.15, 1.47 ± 0.15, 3.85 ± 0.15 and 2.00 ± 0.15, respectively. In all groups except for IPS e.max, the mean opalescence of 1‐mm‐thick specimens was higher than that of 0.5‐mm‐thick specimens. Conclusion Type and thickness of ceramic affect its opalescence. The opalescence of all ceramic specimens tested in this study with 0.5 and 1 mm thicknesses was lower than that of the enamel.
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Affiliation(s)
- Sara Valizadeh
- Dental Research Center, Dentistry Research Institute, Restorative Dentistry Department, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Alireza Mahmoudi Nahavandi
- Color Imaging and Color Image Processing Department, Institute for Color Science and Technology (ICST), Tehran, Iran
| | - Marzieh Daryadar
- Restorative Dentist, Tehran University of Medical Sciences, Tehran, Iran
| | - Mutlu Özcan
- Division of Dental Biomaterials, Center for Dental and Oral Medicine, Clinic for Reconstructive Dentistry, University of Zürich, Zurich, Switzerland
| | - Sedighe Sadat Hashemikamangar
- Dental Research Center, Dentistry Research Institute, Department of Operative Dentistry, Dental School, Tehran University of Medical Sciences, Tehran, Iran
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Kim HK. Optical and Mechanical Properties of Highly Translucent Dental Zirconia. MATERIALS 2020; 13:ma13153395. [PMID: 32751942 PMCID: PMC7435650 DOI: 10.3390/ma13153395] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 12/18/2022]
Abstract
The aim was to evaluate the translucency, opalescence, and fluorescence of highly translucent zirconia, lithium disilicate, and bovine teeth. One mm-thick specimens of five monolithic zirconia systems, two glass-ceramics, and bovine enamel/dentin were investigated. A spectrophotometer (Ci7600) was used to measure the CIELab color coordinates, and the translucency and opalescence values were obtained. For evaluating the fluorescence emission, the differences in spectral reflectance by the UV component of illumination were calculated. The microstructures of ceramic specimens were examined with a scanning electron microscope and the chemical compositions were determined with an X-ray fluorescence spectrometer. Mechanical properties were appraised with three-point bending strength, indentation fracture toughness, and Vickers hardness. Data were analyzed using a one-way ANOVA, followed by Tukey’s multiple comparison test (α = 0.05). A higher yttria content (5 mol%) significantly improved the translucency of zirconia ceramics, while they were less translucent than lithium disilicate (p < 0.05). Lowering the alumina content below 0.05 wt.% enhanced the translucency (p < 0.05), but a small amount of alumina was still required to obtain full densification. 0.05 wt.% Fe was used to increase the chroma of zirconia specimens without compromising their mechanical properties. The Er-containing zirconia specimen showed a maximal fluorescence emission at 430 nm. The degree of opalescence was affected by the microstructures of ceramic materials. The microstructure, incorporation of a secondary phase, and sintering behavior can have a strong impact on the final mechanical and optical properties of dental ceramics. Addition of small amounts of metal oxides can affect the translucency, opalescence or fluorescence qualities of zirconia
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Affiliation(s)
- Hee-Kyung Kim
- Department of Prosthodontics, Institute of Oral Health Science, Ajou University School of Medicine, Suwon 16499, Korea
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Kurt M, Bankoğlu Güngör M, Karakoca Nemli S, Turhan Bal B. Effects of glazing methods on the optical and surface properties of silicate ceramics. J Prosthodont Res 2020; 64:202-209. [DOI: 10.1016/j.jpor.2019.07.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 07/02/2019] [Accepted: 07/09/2019] [Indexed: 11/28/2022]
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PEKKAN G, PEKKAN K, BAYINDIR BÇ, ÖZCAN M, KARASU B. Factors affecting the translucency of monolithic zirconia ceramics: A review from materials science perspective. Dent Mater J 2020; 39:1-8. [DOI: 10.4012/dmj.2019-098] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Gürel PEKKAN
- Department of Prosthodontics, Faculty of Dentistry, Tekirdag Namik Kemal University
| | - Keriman PEKKAN
- Department of Ceramics and Glass, Faculty of Fine Arts, Kutahya Dumlupinar University
| | | | - Mutlu ÖZCAN
- Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Center for Dental and Oral Medicine, Dental Materials Unit, University of Zürich
| | - Bekir KARASU
- Department of Metallurgical and Materials Engineering, Faculty of Engineering, Eskisehir Technical University
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Effects of Different Thickness Combinations of Core and Veneer Ceramics on Optical Properties of CAD-CAM Glass-Ceramics. BIOMED RESEARCH INTERNATIONAL 2019; 2019:5856482. [PMID: 30949503 PMCID: PMC6425410 DOI: 10.1155/2019/5856482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/15/2019] [Accepted: 02/14/2019] [Indexed: 11/17/2022]
Abstract
The goal of this study was to evaluate the effects of different core and veneer thicknesses on the translucency (T%), average light transmittance (T), translucency parameter (TP), contrast ratio (CR), and spectral reflectance (R) of glass-ceramics using a computer-aided design/computer-aided manufacturing (CAD-CAM) process. In all, 42 specimens (11mm × 11mm) were prepared and divided into six groups (n = 7 for each group). Core materials (IPS e.max CAD; IPS Empress CAD, LT A2 shade) of different thicknesses (0.8, 1.0, and 1.2mm) were fabricated. Each veneer material (thicknesses of 0.7, 0.5, and 0.3mm) was combined with its compatible core ceramic. Each core material was overlapped with its corresponding veneer material to obtain a 1.5-mm thickness by using three different combinations: (0.8+0.7), (1.0+0.5), and (1.2+0.3) mm. A spectrophotometer and color data software were used to measure the T%, T, TP, CR, and R values of each ceramic. The results were statistically analyzed using two-way analysis of variables (ANOVA) and regression analysis (p<0.05). Two-way ANOVA revealed that T%, T, TP, and CR were significantly influenced by the different thicknesses of the core-veneer combinations (p<0.001). At a certain thickness, as the veneer thickness increased and core thickness decreased, T and T% all increased. Regression analysis of the ceramic materials indicated a reduction in T and T% for certain core-veneer combinations. Analysis also revealed that T% and T were all affected by different core-veneer combinations. The T% value was 74.31 for the EM group and 72.81 for the EP group when the thickness of the core was 1.2 mm and the veneer was 0.3 mm. The R value of EM2 was lower than EM1 and EM3. In conclusion, the optical properties were influenced by different core-veneer combinations.
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Rafael CF, Cesar PF, Fredel M, Magini RDS, Liebermann A, Maziero Volpato CA. Impact of laboratory treatment with coloring and fluorescent liquids on the optical properties of zirconia before and after accelerated aging. J Prosthet Dent 2018; 120:276-281. [PMID: 29551373 DOI: 10.1016/j.prosdent.2017.10.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 10/22/2017] [Accepted: 10/23/2017] [Indexed: 10/17/2022]
Abstract
STATEMENT OF PROBLEM Laboratory procedures, such as dipping in coloring and fluorescent liquids, can be used to improve the optical properties of zirconia. However, information is lacking on the effect of these liquids. PURPOSE The purpose of this in vitro study was to evaluate the color differences and degree of fluorescence of zirconia (3Y-TZP) treated with coloring and fluorescent liquids before and after an accelerated aging protocol. MATERIAL AND METHODS Forty disk-shaped specimens of 3Y-TZP were fabricated by milling and separated according to the laboratory treatment performed: white zirconia (control group); zirconia treated with coloring liquid (A2 group); zirconia treated with fluorescent liquid (fluorescent group); and zirconia treated with both liquids (A2 fluorescent group). The L*a*b* coordinates before aging (T0) were obtained with a spectrophotometer, and the degree of fluorescence was measured. The disks were subjected to accelerated aging for 1 hour (T1) and 5 hours (T2). Measurements were made before and after each time interval. Color differences (ΔE00) were calculated using the CIEDE2000 formula and analyzed by 2-way ANOVA. Lightness (ΔL'), chroma (ΔC'), and hue differences (ΔH') were analyzed by multivariate ANOVA. Degrees of fluorescence were obtained as percentages and were analyzed by 2-way ANOVA. Multiple comparisons were performed by the Tukey HSD test (α=.05). RESULTS Color differences were observed when 3Y-TZP disks were treated with coloring (7.91 ΔE00), with fluorescent liquid (5.81 ΔE00), and with both liquids (5.52 ΔE00). Accelerated aging resulted in color differences in the T2 A2 group (6.74 ΔE00) and at both times evaluated in the fluorescent group (T1=8.59 ΔE00 and T2=8.47 ΔE00) (P<.001). In the A2 fluorescent group, the degree of fluorescence was not influenced significantly (P>.05). The use of fluorescent liquid influenced the degree of fluorescence in the fluorescent group (T0=20%). CONCLUSIONS Significant differences in color, lightness, chroma, and hue were achieved in all tested groups before and after aging. The degree of fluorescence was statistically different only in the fluorescent group and was not influenced by accelerated aging.
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Affiliation(s)
- Caroline Freitas Rafael
- Postdoctoral student, Department of Dentistry, Federal University of Santa Catarina, Florianópolis, Brazil, and Department of Prosthodontics, Dental School, Ludwig-Maximilians University, Munich, Germany.
| | - Paulo Francisco Cesar
- Professor, Department of Biomaterials and Oral Biology, University of Sao Paulo, Sao Paulo, Brazil
| | - Marcio Fredel
- Professor, Department of Engineering, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Ricardo de Souza Magini
- Professor, Department of Dentistry, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Anja Liebermann
- Assistant Professor, Department of Prosthetic Dentistry, Ludwig-Maximilians Universität München, LMU München, Munich, Germany
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Tabatabaian F. Color in Zirconia-Based Restorations and Related Factors: A Literature Review. J Prosthodont 2018; 27:201-211. [DOI: 10.1111/jopr.12740] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2017] [Indexed: 11/30/2022] Open
Affiliation(s)
- Farhad Tabatabaian
- Department of Prosthodontics, School of Dentistry; Shahid Beheshti University of Medical Sciences; Tehran Iran
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Kaizer MR, Gierthmuehlen PC, dos Santos MBF, Cava SS, Zhang Y. Speed sintering translucent zirconia for chairside one-visit dental restorations: Optical, mechanical, and wear characteristics. CERAMICS INTERNATIONAL 2017; 43:10999-11005. [PMID: 29097830 PMCID: PMC5662116 DOI: 10.1016/j.ceramint.2017.05.141] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The fabrication of zirconia dental restorations is a time-consuming process due to traditional slow sintering schemes; zirconia (Y-TZP) produced by these conventional routes are predominantly opaque. Novel speed sintering protocols have been developed to meet the demand for time and cost effective chairside CAD/CAM-produced restorations, as well as to control ceramic microstructures for better translucency. Although the speed sintering protocols have already been used to densify dental Y-TZP, the wear properties of these restorations remain elusive. Fast heating and cooling rates, as well as shorter sintering dwell times are known to affect the microstructure and properties of zirconia. Thus, we hypothesize that speed sintered zirconia dental restorations possess distinct wear and physical characteristics relative to their conventionally sintered counterparts. Glazed monolithic molar crowns of translucent Y-TZP (inCoris TZI, Sirona) were fabricated using three distinct sintering profiles: Super-speed (SS, 1580 °C, dwell time 10 min), Speed (S, 1510 °C, dwell time 25 min), and Long-term (LT, 1510 °C, dwell time 120 min). Microstructural, optical and wear properties were investigated. Crowns that were super-speed sintered possessed higher translucency. Areas of mild and severe wear were observed on the zirconia surface in all groups. Micropits in the wear crater were less frequent for the LT group. Groups S and SS exhibited more surface pits, which caused a scratched steatite surface that is associated with a greater volume loss. Tetragonal to monoclinic phase transformation, resulting from the sliding wear process, was present in all three groups. Although all test groups had withstood thermo-mechanical challenges, the presence of hairline cracks emanating from the occlusal wear facets and extending deep into the restoration indicates their susceptibility to fatigue sliding contact fracture.
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Affiliation(s)
- Marina R. Kaizer
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY 10010, USA
- Graduate Program in Materials Science and Engineering, Federal University of Pelotas, Pelotas, Brazil
| | - Petra C. Gierthmuehlen
- Department of Prosthodontics, University Medical Center Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany
| | | | - Sergio S. Cava
- Graduate Program in Materials Science and Engineering, Federal University of Pelotas, Pelotas, Brazil
| | - Yu Zhang
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY 10010, USA
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Alghazzawi TF. The effect of extended aging on the optical properties of different zirconia materials. J Prosthodont Res 2016; 61:305-314. [PMID: 27964931 DOI: 10.1016/j.jpor.2016.11.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 10/12/2016] [Accepted: 11/06/2016] [Indexed: 10/20/2022]
Abstract
PURPOSE The purpose of this study was to determine if the optical properties of zirconia and glass-ceramic (e.max) were affected by low-temperature degradation (aging). METHODS Experiment samples were fabricated with seven zirconia brands (n=10): Zenostar, Zirlux, Katana, Bruxzir, DD-BioZX2, DD-cubeX2, NexxZr; and e.max were used as a control. This resulted in a total of 80 samples in the experiment. The L*, a* and b* were measured for each sample, and then the optical properties including translucency parameter (TP), contrast ratio (CR), and opalescence parameter (OP) were calculated. The samples were aged (20, 40, 60, 80, 100h), and the optical properties were calculated after each interval. RESULTS Most zirconia brands had lower L*, higher a*, higher b* with increased aging, which visually corresponds to darker, redder, and more yellow. Aging also increased CR, lowered TP, and lowered OP. e.max was also affected by aging but still had the highest TP (23.9±2.8), L* (81.7±3.4), and lowest CR (0.41±0.05) compared to any zirconia. The Zenostar had the closest TP (24.1±0.4), and L* (90.2±0.5) values to e.max before aging. However, after 100h of aging, the DD-cubeX2 was least effected and had the highest TP (22.2±0.6) and lowest CR (0.43±0.01) compared with other zirconia samples and highest OP (11.3±0.2) of all ceramic samples. CONCLUSIONS The optical properties of zirconia and e.max materials were affected by aging with the effects increasing with time. The magnitude of change was affected by seven brands of dental zirconia.
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Affiliation(s)
- Tariq F Alghazzawi
- Department of Prosthetic Dental Sciences, College of Dentistry, Taibah University, Medina, Saudi Arabia; Department of Materials Science and Engineering, School of Engineering, The University of Alabama at Birmingham, United States.
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Influence of object translucency on the scanning accuracy of a powder-free intraoral scanner: A laboratory study. J Prosthet Dent 2016; 117:93-101. [PMID: 27460324 DOI: 10.1016/j.prosdent.2016.04.008] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 04/18/2016] [Accepted: 04/20/2016] [Indexed: 12/31/2022]
Abstract
STATEMENT OF PROBLEM Limited information is available regarding the influence of object translucency on the scanning accuracy of a powder-free intraoral scanner. PURPOSE The purpose of this in vitro study was to evaluate the scanning accuracy of a confocal microscopy principle powder-free intraoral scanner on ceramic copings and to analyze the relationship between scanning accuracy and object translucency. METHODS Six slice specimens (12×10 mm) and 6 offset copings (1.00-mm thickness) were made from different translucent homogeneous ceramic blocks (CEREC Blocs, S0-M to S5-M, highest to lowest translucency). The primary sintered zirconia offset coping was produced in the same way as the control. Optical parameters related to the translucency of each slice were measured with a spectrophotometer. Three-dimensional (3D) datasets of the surface morphology of offset copings were obtained by using the intraoral scanner. The same white wax resin bases were used for registration. Quantitative parameters of scanning trueness and precision were measured. One-way ANOVA was used to analyze the values of each parameter among the 6 ceramic blocks. Bivariate correlation was used to analyze the relationships between each parameter of scanning accuracy and translucency (α=.05). RESULTS Translucent copings showed a positive 3D bias (S0-M to S5-M: 0.149 ±0.038 mm to 0.068 ±0.020 mm), a narrower collar diameter (Dd=-0.067 mm), larger convergence angle (ΔΦ=2.79 degrees), and larger curvature radius of the internal gingivoaxial corner (Δρ=0.236 mm). The smaller the percentage sum of scattering and absorption, the greater was the occurrence of scanning bias (r=-0.918) and curvature (r=-0.935) decrease. CONCLUSIONS Use of the tested powder-free intraoral scanner, higher translucency objects (greater translucency than S1-M/A1C) resulted in lower scanning accuracy and morphological changes. Therefore, more suitable methods of measurement are still required.
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 02/26/2016] [Indexed: 10/22/2022]
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Thickness dependence of light transmittance, translucency and opalescence of a ceria-stabilized zirconia/alumina nanocomposite for dental applications. Dent Mater 2016; 32:660-7. [DOI: 10.1016/j.dental.2016.02.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 07/17/2015] [Accepted: 02/03/2016] [Indexed: 11/17/2022]
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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] [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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LEE YK. Opalescence of human teeth and dental esthetic restorative materials. Dent Mater J 2016; 35:845-854. [PMID: 27546859 DOI: 10.4012/dmj.2016-091] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Yong-Keun LEE
- Institute for Clinical Performance of Biomaterials (ICPB) and ETN Dental Clinic
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Dentin translucency and color evaluation in human incisors, canines, and molars. J Prosthet Dent 2015; 115:475-81. [PMID: 26548886 DOI: 10.1016/j.prosdent.2015.07.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 07/16/2015] [Accepted: 07/21/2015] [Indexed: 11/20/2022]
Abstract
STATEMENT OF PROBLEM For restorations with excellent esthetics, an understanding of the optical properties of human dentin is needed. Little information is available on the translucency and color parameters of dentin and its relationship to tooth type and position. PURPOSE The purpose of this in vitro study was to investigate the translucency and CIELab color coordinates of human dentin in both anterior (incisors and canines) and posterior teeth (molars) by using spectrophotometric and spectroradiometric assessment methods. MATERIAL AND METHODS Uniformly thick specimens (2 mm) of midcoronal human dentin were taken from 33 central and lateral incisors, 7 canines, and 33 molars (all maxillary teeth). The CIELab color coordinates were measured with a clinical spectrophotometer (Easyshade Compact) and a noncontact spectroradiometer (SpectraScan PR-704). The translucency parameter (TP) was calculated. Bland-Altman plots and Wilcoxon signed rank tests for paired samples were used to assess the agreement of the 2 measurement techniques. The differences between anterior and posterior dentin specimens regarding color coordinates and the translucency parameter were analyzed using Mann-Whitney-Wilcoxon rank sum tests. RESULTS Statistically significant differences between spectrophotometric and spectroradiometric measurements of the TP and CIELab color coordinates were found in both groups of dentin specimens (P<.05). TP values of molar dentin specimens were significantly higher than those of the anterior ones, regardless of the assessment method (P<.001). Dentin specimens of the anterior teeth exhibited higher L∗ values but lower a∗ and b∗ values on both black and white backgrounds compared with molar dentin specimens. CONCLUSIONS The dentin of anterior teeth was found to be lighter but less translucent and less chromatic than in molars, regardless of the assessment method used.
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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] [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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Dikicier S, Ayyildiz S, Ozen J, Sipahi C. Effect of varying core thicknesses and artificial aging on the color difference of different all-ceramic materials. Acta Odontol Scand 2014; 72:623-9. [PMID: 24773131 DOI: 10.3109/00016357.2013.879997] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Clinicians should reserve all-ceramics with high translucency for clinical applications in which high-level esthetics are required. Furthermore, it is unclear whether a correlation exists between core thickness and color change. The aim of this study was to examine the effects of different core thicknesses and artificial aging on the color stability of three all-ceramic systems. MATERIALS AND METHODS Ninety disc-shaped cores with different thicknesses (0.5 mm, 0.8 mm and 1.0 mm) were prepared from three all-ceramic systems, In-Ceram Alumina (IC), IPS e.max Press (EM) and Katana (K). The colors of the samples were measured with a spectrophotometer and the color parameters (L*, a*, b*, ΔE) were calculated according to the CIE L*a*b* (Commission Internationale de L'Eclairage) color system before and after aging. RESULTS The effects of aging on color parameters were statistically significant (p < 0.001), regardless of core thickness. For all systems, the CIE a* values increased as the thickness of the core increased. Conversely, such increases in core porcelain thickness were correlated with decreasing CIE L* and b* values. Core thickness had a statistically significant effect on color change among the groups. CONCLUSIONS Different core thicknesses (from 1.0-0.5 mm) and artificial aging affected color stability of the all-ceramic materials tested.
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Affiliation(s)
- Sibel Dikicier
- Department of Prosthodontics, Corlu Military Hospital , Tekirdag , Turkey
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Della Bona A, Nogueira AD, Pecho OE. Optical properties of CAD–CAM ceramic systems. J Dent 2014; 42:1202-9. [DOI: 10.1016/j.jdent.2014.07.005] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 07/04/2014] [Accepted: 07/07/2014] [Indexed: 11/26/2022] Open
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Johnston WM. Review of translucency determinations and applications to dental materials. J ESTHET RESTOR DENT 2014; 26:217-23. [PMID: 24975048 DOI: 10.1111/jerd.12112] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
STATEMENT OF PROBLEM There are several ways to measure the translucency of materials, as various basic colorimetric concepts have been used to describe the translucency of natural and esthetic dental materials. There are currently no guidelines regarding which method to use to describe the translucency of these materials. PURPOSES OF STUDY Two initial purposes of this study are to review the initial developments of the major translucency measurement methods first in the color science literature and then in the dentistry literature, and to review in the dentistry literature the recent uses of the various translucency measurement methods in light of the objectives of the presented research. MATERIAL AND METHODS A major color science textbook was reviewed to obtain the background information and selected references regarding the original methods of opacity measurement and the original references regarding the development and use of a translucency parameter were also reviewed. Then the recent dentistry literature was reviewed to describe the uses of the various methods of opacity or translucency determinations for various dental materials. RESULTS The three major methods of translucency measurement were found to be contrast ratio, transmittance, and translucency parameter, with the contrast ratio and transmittance methods each having the possibility of being either luminous or spectral. Translucency measurements were mainly used to describe dental resin composites and dental ceramic materials, but prosthetic elastomers, fiber posts, orthodontic brackets, natural tooth dentine and enamel, and combinations of materials were also studied using at least one of these methods. CONCLUSIONS The more-developed use of models that relate the thickness of the translucent materials to the translucency measurement of interest is encouraged. Also, care must be taken when comparing previously generated translucency measurements with any newly generated data because technical details of the thickness and the backings used in previous research must be matched or adjustments must be made to make any newly generated data comparable with published values. CLINICAL SIGNIFICANCE The method of specifying the translucency of esthetic dental materials may be based on clinical appearance requirements of the patient, on technical demands of optimizing the setting of underlying material, or on both. The method or methods used to describe translucency may provide clinically relevant information in order for the clinician to select the optimum material to satisfy these requirements.
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Affiliation(s)
- William M Johnston
- Division of General Dentistry and Materials Science, College of Dentistry, The Ohio State University, Columbus, OH, USA
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Niu E, Agustin M, Douglas RD. Color match of machinable lithium disilicate ceramics: Effects of cement color and thickness. J Prosthet Dent 2014; 111:42-50. [DOI: 10.1016/j.prosdent.2013.09.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Niu E, Agustin M, Douglas RD. Color match of machinable lithium disilicate ceramics: Effects of foundation restoration. J Prosthet Dent 2013; 110:501-9. [DOI: 10.1016/j.prosdent.2013.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Kürklü D, Azer SS, Yilmaz B, Johnston WM. Porcelain thickness and cement shade effects on the colour and translucency of porcelain veneering materials. J Dent 2013; 41:1043-50. [DOI: 10.1016/j.jdent.2013.08.017] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 08/20/2013] [Accepted: 08/22/2013] [Indexed: 11/30/2022] Open
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Cekic-Nagas I, Egilmez F, Ergun G, Kaya BM. Light transmittance of zirconia as a function of thickness and microhardness of resin cements under different thicknesses of zirconia. Med Oral Patol Oral Cir Bucal 2013; 18:e212-8. [PMID: 23385497 PMCID: PMC3613872 DOI: 10.4317/medoral.18181] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 08/05/2012] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE The objective of this study was to compare microhardness of resin cements under different thicknesses of zirconia and the light transmittance of zirconia as a function of thickness. STUDY DESIGN A total of 126 disc-shaped specimens (2 mm in height and 5 mm in diameter) were prepared from dual-cured resin cements (RelyX Unicem, Panavia F and Clearfil SA cement). Photoactivation was performed by using quartz tungsten halogen and light emitting diode light curing units under different thicknesses of zirconia. Then the specimens (n=7/per group) were stored in dry conditions in total dark at 37°C for 24 h. The Vicker's hardness test was performed on the resin cement layer with a microhardness tester. Statistical significance was determined using multifactorial analysis of variance (ANOVA) (alpha=.05). Light transmittance of different thicknesses of zirconia (0.3, 0.5 and 0.8 mm) was measured using a hand-held radiometer (Demetron, Kerr). Data were analyzed using one-way ANOVA test (alpha=.05). RESULTS ANOVA revealed that resin cement and light curing unit had significant effects on microhardness (p < 0.001). Additionally, greater zirconia thickness resulted in lower transmittance. There was no correlation between the amount of light transmitted and microhardness of dual-cured resin cements (r = 0.073, p = 0.295). CONCLUSION Although different zirconia thicknesses might result in insufficient light transmission, dual-cured resin cements under zirconia restorations could have adequate microhardness.
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Affiliation(s)
- Isil Cekic-Nagas
- Gazi University, Faculty of Dentistry, Department of Prosthodontics, Ankara, Turkey.
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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] [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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Schmeling M, Maia HP, Baratieri LN. Opalescence of bleached teeth. J Dent 2012; 40 Suppl 1:e35-9. [PMID: 22326850 DOI: 10.1016/j.jdent.2012.01.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 01/23/2012] [Accepted: 01/24/2012] [Indexed: 10/14/2022] Open
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Cekic-Nagas I, Egilmez F, Ergun G. Comparison of light transmittance in different thicknesses of zirconia under various light curing units. J Adv Prosthodont 2012; 4:93-6. [PMID: 22737314 PMCID: PMC3381209 DOI: 10.4047/jap.2012.4.2.93] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 05/02/2012] [Accepted: 05/04/2012] [Indexed: 12/13/2022] Open
Abstract
PURPOSE The objective of this study was to compare the light transmittance of zirconia in different thicknesses using various light curing units. MATERIALS AND METHODS A total of 21 disc-shaped zirconia specimens (5 mm in diameter) in different thicknesses (0.3, 0.5 and 0.8 mm) were prepared. The light transmittance of the specimens under three different light-curing units (quartz tungsten halogen, light-emitting diodes and plasma arc) was compared by using a hand-held radiometer. Statistical significance was determined using two-way ANOVA (α=.05). RESULTS ANOVA revealed that thickness of zirconia and light curing unit had significant effects on light transmittance (P<.001). CONCLUSION Greater thickness of zirconia results in lower light transmittance. Light-emitting diodes light-curing units might be considered as effective as Plasma arc light-curing units or more effective than Quartz-tungsten-halogen light-curing units for polymerization of the resin-based materials.
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Affiliation(s)
- Isil Cekic-Nagas
- Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey
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