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Aydin N, Uslu Kavrama F, Kocak EF. Effect of thickness on the translucency of machinable and printable ceramic-glass polymer materials. J Dent 2024; 147:105129. [PMID: 38878814 DOI: 10.1016/j.jdent.2024.105129] [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: 11/27/2023] [Revised: 06/10/2024] [Accepted: 06/12/2024] [Indexed: 06/30/2024] Open
Abstract
OBJECTIVES To assess the translucency of machinable and printable ceramic-glass polymer materials with different thicknesses. METHODS Five ceramic-glass polymer materials were tested: one 3D-printable material, Permanent Crown resin (3D), two machinable materials available at low translucency (LT) and high translucency (HT) levels, VITA Enamic (VE) HT/LT, and Cerasmart 270 (CS) HT/LT. A total of 100 specimens were produced across 10 subgroups (n = 10) with thicknesses of 1 mm and 1.5 mm. The colour coordinates of the specimens were measured against black and white backgrounds using a spectrophotometer. Translucency was quantified using the Relative Translucency Parameter (RTP), calculated via the CIEDE2000 formula. A two-way ANOVA followed by post-hoc tests with Bonferroni correction (α = 0.05) was used for statistical analysis. RESULTS The RTP for both thicknesses were ranked as follows: CSHT > VEHT > CSLT > 3D > VELT. The RTP of the 3D was lower than that of the HT machinable materials (CSHT and VEHT) for both thicknesses (p < 0.05). No significant difference was observed between the RTP of 3D and CSLT at 1.5 mm (p = 1.000); however, at 1 mm, the RTP of the 3D was lower than that of the CSLT (p < 0.05). Notably, the 3D showed the least translucency difference with a 0.5 mm increase in thickness. CONCLUSIONS Printable ceramic-glass polymer materials demonstrated lower translucency than HT machinable ceramic-glass polymer materials. Both the thickness and type significantly influenced the translucency of the LT machinable counterparts compared to the printable ceramic-glass polymer material. CLINICAL SIGNIFICANCE Printable ceramic-glass polymer resins may be a suitable option for minimally invasive procedures, especially when attempting to mask undesirable-coloured abutments. When selecting HT machinable ceramic-glass polymers, clinicians should pay greater attention to the abutment colour and thickness of the restorative material.
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Affiliation(s)
- Nazli Aydin
- Cukurova University, Faculty of Dentistry, Department of Prosthodontics, Adana, Turkey; The Abdi Sutcu Vocational School of Health Services, Cukurova University, Balcali, Adana, Turkey.
| | | | - Elif Figen Kocak
- Dokuz Eylul University, Faculty of Dentistry, Department of Prosthodontics, Izmir, Turkey
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Abounassif FM, Alfaraj A, Gadah T, Yang CC, Chu TMG, Lin WS. Color stability of precolored and extrinsically colored monolithic multilayered polychromatic zirconia: Effects of surface finishing and aging. J Prosthodont 2024. [PMID: 38923252 DOI: 10.1111/jopr.13875] [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: 01/06/2024] [Accepted: 05/13/2024] [Indexed: 06/28/2024] Open
Abstract
PURPOSE To explore the impact of zirconia types, coloring methods, and surface finishing on the color stability of monolithic multilayered polychromatic zirconia after artificial aging, including thermocycling and simulated toothbrushing. MATERIALS AND METHODS Eighty square-shaped zirconia samples were divided into 2 types (M3Y-TZP and M6Y-PSZ), further categorized based on coloring methods (precolored and extrinsically colored) and surface finishing techniques (mechanical polishing or glazing). The color stability was assessed using the CIEDE2000 formula. Artificial aging was simulated via thermocycling and toothbrushing. All samples were analyzed with a spectrophotometer to determine the post-aging color changes (ΔE00). The ΔE00 were interpreted and classified using the 50:50% perceptibility threshold (PT) and the 50:50% acceptability threshold (AT). Comparisons between groups for ΔE00 differences were performed using three-way ANOVA, with pairwise comparisons facilitated by Fisher's protected least significant difference test, α = 0.05. RESULTS The study results indicated significant impacts of zirconia type, coloring method, and surface finishing on color stability. The M6Y groups experienced significantly greater color changes (6.61 ± 1.63) compared to the M3Y groups (3.40 ± 2.24), p < 0.0001. For both types of zirconia, extrinsically colored samples exhibited significantly higher ΔE00 when mechanically polished (p = 0.004). However, surface finishing had no significant effect on ΔE00 in precolored samples of either zirconia material (p = 1.000). The evaluation and categorization of ΔE00 variations indicated that nearly all color changes in the M6Y groups, regardless of being precolored, extrinsically colored, polished, or glazed, were deemed extremely unacceptable (Grade 1). In contrast, the M3Y groups showed more acceptable results, with the majority of color changes classified as moderately unacceptable (Grade 3). CONCLUSIONS The color stability of multilayered polychromatic zirconia is influenced by the type of material, extrinsic coloring, and the chosen surface treatment post-artificial aging. The translucent 6Y-PSZ exhibited lower color stability, especially with only mechanical polishing. For the fabrication of M3Y-TZP and 6Y-PSZ monolithic multilayered polychromatic zirconia restorations, extrinsic coloring should be paired with glazing to maintain color stability. Conversely, in the absence of extrinsic coloring, both glazing and mechanical polishing are effective in preserving color stability.
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Affiliation(s)
- Feras M Abounassif
- Dental Department, Al Imam Abdulrahman Bin Faisal Hospital, National Guard Health Affairs, Dammam, Saudi Arabia
| | - Amal Alfaraj
- Department of Prosthodontics, College of Dentistry, King Faisal University, Al Ahsa, Saudi Arabia
- Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, Indiana, USA
| | - Thuraya Gadah
- Department of Prosthodontics, College of Dentistry, King Khalid University, Abha, Saudi Arabia
| | - Chao-Chieh Yang
- Advanced Education Program in Prosthodontics, Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, Indiana, USA
| | - Tien-Min G Chu
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, Indiana, USA
| | - Wei-Shao Lin
- Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, Indiana, USA
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Jamali M, Ezoji F, Esmaeili B, Khafri S. Comparative effects of glazing versus polishing on mechanical, optical, and surface properties of zirconia ceramics with different translucencies. Clin Exp Dent Res 2024; 10:e884. [PMID: 38798053 PMCID: PMC11128755 DOI: 10.1002/cre2.884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 01/21/2024] [Accepted: 01/26/2024] [Indexed: 05/29/2024] Open
Abstract
OBJECTIVES This study compared the effects of glazing versus polishing on mechanical, optical, and surface properties of zirconia ceramics with different translucencies. MATERIALS AND METHODS In this in vitro study, 120 bar-shaped specimens (25 × 4 × 1.2 mm) were fabricated from three different types of zirconia with different translucencies (n = 40, DD Bio ZW, ZX2, and Cube X2). After sintering, each zirconia group was randomly divided into five subgroups of control (glazing), glazing + bur abrasion, glazing + bur abrasion + polishing with EVE Diacera® kit, glazing + bur abrasion + reglazing, and glazing + bur abrasion + polishing with EVE Diacera® kit + reglazing. The specimens underwent surface roughness, hardness, flexural strength, and translucency tests, as well as X-ray diffraction (XRD) and scanning electron microscopy (SEM) for assessment of surface topography. Data were analyzed by one-way analysis of variance, Tukey test, and Pearson test (α = .05). RESULTS Flexural strength, surface hardness, and translucency were significantly correlated with zirconia type. ZW zirconia had significantly higher flexural strength and surface hardness and significantly lower translucency than Cube X2 and ZX2 (p < .001). Surface roughness had no significant correlation with zirconia type (p = .274). Polishing created the smoothest, and bur abrasion created the roughest surface (p < .001). Flexural strength and hardness in most experimental groups were significantly lower than in the control group (p < .001). Translucency was not significantly different in bur abrasion and polishing groups, compared with the control group; however, reglazing significantly increased the translucency (p < .001). SEM micrographs confirmed the surface roughness results. XRD showed monoclinic phase only in reglazed groups. CONCLUSION Of different surface treatments, polishing improved the surface properties and caused the smallest change in mechanical properties of zirconia with different translucencies.
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Affiliation(s)
- Maryam Jamali
- Student Research CommitteeBabol University of Medical SciencesBabolIran
| | - Fariba Ezoji
- Department of Restorative Dentistry, Dental Materials Research Center, Health Research InstituteBabol University of Medical SciencesBabolIran
| | - Behnaz Esmaeili
- Department of Restorative Dentistry, Dental Materials Research Center, Health Research InstituteBabol University of Medical SciencesBabolIran
| | - Soraya Khafri
- Department of Biostatistics and Epidemiology, School of Public HealthBabol University of Medical SciencesBabolIran
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İnal CB, Bankoğlu Güngör M, Karakoca Nemli S. Effects of Coloring Liquid Dipping Time and Surface Finishing Procedures on the Optical Properties of Monolithic Zirconia. Niger J Clin Pract 2024; 27:496-503. [PMID: 38679773 DOI: 10.4103/njcp.njcp_794_23] [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: 11/13/2023] [Accepted: 02/08/2024] [Indexed: 05/01/2024]
Abstract
BACKGROUND Monolithic zirconia restorations can be produced from self-colored or uncolored blocks. The coloring procedure of uncolored blocks and surface treatments may affect the appearance of the restoration. AIM The purpose of this study is to evaluate the effect of liquid coloring and surface treatments on optical properties of translucent monolithic zirconia. METHODS All specimens were cut from zirconia blocks with a thickness of 1 mm. Specimens were dipped in the coloring liquids for 3 min, 5 min, and 7 min and then divided into groups of 10 specimens for surface treatments. Glaze and mechanical polishing were applied, and the color of the specimens was measured under the D65 lighting condition with a spectrophotometer device. Color values obtained from the CIE Lab formula and the translucency parameter (TP), opalescence parameter (OP), and contrast ratio (CR) were calculated. The normality of the data was confirmed with the Shapiro-Wilk test. A three-way analysis of variance (ANOVA) was used to assess the effect of dipping time, liquid shade, and surface treatments. RESULTS The effect of liquid shade and dipping time on the TP, OP, and CR parameters were statistically significant, and the TP values were reduced with the application of coloring liquid. Mechanical polishing groups had higher OP values and lower TP values than glazed groups. CONCLUSION In cases where high translucency is required, it may be advisable to use self-colored blocks and apply glaze as a surface treatment to achieve the desired optical properties.
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Affiliation(s)
- C B İnal
- Prosthodontist at Private Practice, 06490 Emek, Çankaya, Ankara, Türkiye
| | - M Bankoğlu Güngör
- Department of Prosthodontics, Faculty of Dentistry, Gazi University, 06490 Emek, Çankaya, Ankara, Türkiye
| | - S Karakoca Nemli
- Department of Prosthodontics, Faculty of Dentistry, Gazi University, 06490 Emek, Çankaya, Ankara, Türkiye
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Toksoy D, Önöral Ö. Influence of glazing and aging on the marginal, axial, axio-occlusal, and occlusal fit of 3-unit monolithic zirconia restorations fabricated using additive and subtractive techniques. J Prosthet Dent 2024; 131:658.e1-658.e9. [PMID: 38342643 DOI: 10.1016/j.prosdent.2024.01.010] [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: 10/04/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 02/13/2024]
Abstract
STATEMENT OF PROBLEM Studies are sparse on how glazing and aging influence the fit of additively fabricated monolithic zirconia restorations. PURPOSE The purpose of this in vitro study was to assess the effect of glazing and aging on the fit of 3-unit monolithic zirconia restorations fabricated using different techniques. MATERIAL AND METHODS A total of 32 monolithic zirconia restorations were fabricated for a typodont model by using 4 distinct techniques (subtractive fabrication [SF], stereolithography [SLA], digital light processing [DLP], and lithography-based ceramic manufacturing [LCM]). The silicone replica approach was adopted to measure the discrepancy values for premolar and molar abutments after sintering, glazing, and 1 year of aging. The silicone replicas were sliced into mesiodistal and buccopalatal cross-sections, and digital micrographs of the cross-sections were made with a ×80 stereomicroscope. An inherent measuring program was run to record the discrepancy values (µm). Repeated-measures 2-way ANOVAs with the Bonferroni post hoc test were used to statistically analyze the acquired data. (α=.05). RESULTS From the repeated measures 2-way ANOVAs, both the glazing×fabrication technique and the aging×fabrication technique interactions were not statistically significant (P>.05). Glazing significantly influenced premolar abutment marginal (P=.022) and occlusal (P=.007) discrepancy values, as well as molar abutment marginal discrepancy values (P=.047). Aging had a statistically significant effect on premolar abutment marginal (P=.008) and occlusal (P=.011) discrepancy values, as well as molar abutment occlusal discrepancy values (P=.039). In both the glazing and aging data, for all areas of interest, statistically significant differences were detected among the fabrication techniques (P<.05). The LCM group had the lowest discrepancy values, followed by the SLA, SF, and DLP groups. CONCLUSIONS The LCM and SLA groups outperformed the other groups in terms of fit accuracy. The glazing and aging procedures altered the discrepancy values. The marginal discrepancy values of all groups were below the threshold of clinical acceptability (<120 µm).
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Affiliation(s)
- Dilem Toksoy
- Research Assistant, Department of Prosthetic Dentistry, Faculty of Dentistry, Near East University, Nicosia, North Cyprus
| | - Özay Önöral
- Associate Professor, Department of Prosthetic Dentistry, Faculty of Dentistry, Near East University, Nicosia, North Cyprus.
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Stevens CD, Renné WG, Vág J. Translucency of chairside monolithic zirconias using different sintering ovens: An in vitro investigation. J Dent 2024; 142:104839. [PMID: 38216029 DOI: 10.1016/j.jdent.2024.104839] [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: 11/30/2023] [Revised: 12/13/2023] [Accepted: 01/09/2024] [Indexed: 01/14/2024] Open
Abstract
OBJECTIVE To evaluate the translucency of several monolithic zirconias (MZ) processed in various sintering ovens designed for single-visit, chairside use. METHODS Discs (n = 40) from zirconia blocks were fabricated for each MZ at manufacturer-recommended minimal thicknesses, as provided in each material's instructions for use: IPS e.max ZirCAD LT (ZLT); CEREC Zirconia+ (CZ+); 3M Chairside (3M); KATANA Zirconia (KT). Groups (n = 10) were sintered following manufacturer instructions for each oven: CEREC SpeedFire, Ivoclar CS4, Ivoclar CS6, and Ivoclar S2 (laboratory furnace control). Specimens were highly polished on one side and glazed on the other. Each side was measured with a spectrophotometer against white and black backgrounds to determine translucency parameter (TP) and contrast ratio (CR) values. Results for TP and CR for each material and oven combination were compared with a linear mixed model. Oven precision was evaluated using the Kruskall-Wallis test. RESULTS Glazed specimens were more translucent than polished ones (p < 0.001). ZLT and CZ+ were more translucent than 3M and KT regardless of the sintering oven (p < 0.01). Several oven/material combinations reached or exceeded the S2 oven TP: CS4 with CZ+ and 3M; CS6 with ZLT and KT (p < 0.01). SpeedFire was significantly less precise (p < 0.05) and produced lower TP values for ZLT, CZ+, and KT (p < 0.01). Results for TP and CR were highly correlated. CONCLUSIONS MZ surface finish, material thickness, and oven used all had a significant effect on translucency. Some chairside-oriented solutions produced results with translucency equal to conventionally processed zirconia. CLINICAL SIGNIFICANCE The translucency of a ceramic restoration is an important factor in determining its esthetics. Clinicians desiring the most esthetic outcomes with monolithic zirconia should be aware of the significant effects that surface finishing, material thickness, and the sintering oven used can have on restoration translucency.
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Affiliation(s)
| | | | - János Vág
- Department of Restorative Dentistry and Endodontics, Semmelweis University, Budapest, Hungary.
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Hoffmann M, Mayinger F, Stawarczyk B. Influence of different surface finishing procedures of strength-gradient multilayered zirconia crowns on two-body wear and fracture load: Lithium silicate or leucite glazing versus polishing? J Mech Behav Biomed Mater 2024; 150:106307. [PMID: 38071838 DOI: 10.1016/j.jmbbm.2023.106307] [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: 10/01/2023] [Revised: 11/29/2023] [Accepted: 12/03/2023] [Indexed: 01/09/2024]
Abstract
OBJECTIVES To examine the influence of different finishing procedures on the surface roughness, wear resistance and fracture load of strength-gradient multilayered zirconia. MATERIALS AND METHODS Zirconia crowns (Multilayer 3D pro; n = 96) were manufactured and treated with a lithium-silicate- (LISI_S), leucite-based glaze spray (LEU_S), leucite-based glaze mass (LEU_M) or polished (POL). Natural molars (CG; n = 24) acted as a control. Roughness was determined on flat glazed specimens (n = 28). Two-body wear was examined by digitalizing and matching the occlusal surface before and after thermo-mechanical aging (6,000 thermal and 1,200,000 chewing cycles). The groups were split to measure fracture load initially and after aging. Kolmogorov-Smirnov, Spearman correlation, Kruskal-Wallis-H, Levene's test, one-way ANOVA with Scheffé post-hoc and Weibull modulus were computed. RESULTS POL presented the lowest and LEU_S the highest roughness. Following POL, no ceramic loss was observed. LISI_S, LEU_S and LEU_M showed lower ceramic wear than the CG. The lowest wear of the antagonist was observed for the CG. LISI_S showed a lower antagonistic wear than LEU_S, LEU_M and POL. LISI_S, LEU_S, LEU_M and POL showed higher fracture load values and Weibull moduli than the CG. Artificial aging did not impact the fracture load or Weibull moduli. SIGNIFICANCE With glazed groups showing height losses closer to the CG, glazing should be preferred to polishing when approximating the wear behavior of a natural dentition. Finishing of monolithic zirconia by glazing with a lithium silicate-based spray is recommended to preserve the antagonists. All examined zirconia crowns presented sufficient mechanical properties to withstand masticatory forces, even after prolonged aging.
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Affiliation(s)
- Moritz Hoffmann
- Department of Prosthetic Dentistry, Dental School, University Hospital, LMU Munich, Goethestraße 70, 80336, Munich, Germany.
| | - Felicitas Mayinger
- Department of Prosthetic Dentistry, Dental School, University Hospital, LMU Munich, Goethestraße 70, 80336, Munich, Germany
| | - Bogna Stawarczyk
- Department of Prosthetic Dentistry, Dental School, University Hospital, LMU Munich, Goethestraße 70, 80336, Munich, Germany
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Hajhamid B, Bozec L, Tenenbaum H, De Souza G, Somogyi-Ganss E. Effect of artificial aging on optical properties and crystalline structure of high-translucency zirconia. J Prosthodont 2024; 33:61-69. [PMID: 36641491 DOI: 10.1111/jopr.13648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 01/10/2023] [Accepted: 01/10/2023] [Indexed: 01/16/2023] Open
Abstract
PURPOSE To investigate the effect of different in vitro aging protocols on the optical properties and crystalline structure of high-translucency (HT) zirconia. MATERIALS AND METHODS Thirty-six specimens of HT and extra-high translucency (XT) zirconia were divided into three groups: control (CO)-no treatment; hydrothermal aging (HA)-autoclave aging for 12.5 h at 134°C, 2 bar; clinically related aging (CRA)-aging in the chewing simulator for 1.2 million cycles, followed by 50,000 thermocycles (5-55°C) and immersion in HCl (pH 1.2) for 15 h. Optical properties, crystalline structure, and surface roughness were analyzed and compared using analysis of variance (5% significance level). RESULTS There was no statistically significant effect of aging on translucency (p = 0.10), but CRA promoted the development of a high contrast ratio (p = 0.03). Aging did not cause significant color changes for HT (p = 0.65) or XT (p = 0.36). The proportion of monoclinic crystals increased to 40% for HT-zirconia after HA and 5% after CRA. No monoclinic crystals were detected for XT groups. There was no effect of aging on surface roughness (p = 0.77). CONCLUSIONS Although hydrothermal aging has been widely used to verify zirconia crystalline stability, it did not generate an effect similar to clinically related aging on the optical properties and crystalline structure of zirconia. HA affected the crystalline structure of HT-zirconia, and CRA compromised the optical properties of XT zirconia.
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Affiliation(s)
- Beshr Hajhamid
- Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Laurent Bozec
- Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Howard Tenenbaum
- Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Grace De Souza
- Department of Comprehensive Dentistry, School of Dentistry, University of Louisville, Louisville, Kentucky, USA
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Hafezeqoran A, Sabanik P, Koodaryan R, Ghalili KM. Effect of sintering speed, aging processes, and different surface treatments on the optical and surface properties of monolithic zirconia restorations. J Prosthet Dent 2023; 130:917-926. [PMID: 35109985 DOI: 10.1016/j.prosdent.2021.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 11/24/2022]
Abstract
STATEMENT OF PROBLEM Advances in dentistry have led to more esthetic and biocompatible restorative materials such as translucent zirconia and to faster and more accurate manufacturing methods. How changes in the surface and optical properties of translucent zirconia affect the esthetics and durability of these restorations under different conditions and manufacturing processes is unclear. PURPOSE The purpose of this in vitro study was to evaluate the effect of the sintering speed, aging process, and different surface treatments on the translucency and surface structure of monolithic zirconia restorations. MATERIAL AND METHODS Prepared typodont teeth were scanned, and 40 three-unit fixed partial dentures (FPDs) and 40 disk specimens were designed and prepared from monolithic zirconia blanks. The specimens were divided into traditional or speed sintering groups (20 FPDs and 20 disks each); half of each group (10 FPDs and 10 disks) was polished with a handpiece at 10 000 rpm, and the other half was glazed. Half of the specimens were thermocycled with 3500 cycles in 5 °C and 55 °C water baths, and the remaining half were not thermocycled. Translucency was measured with a spectrophotometer. Surface free energy was calculated in mNm with a contact angle device; surface roughness was measured in nm with an atomic force microscope. Translucency data were analyzed by the Kruskal-Wallis and Mann-Whitney tests, while surface free energy and surface roughness data were analyzed by 3-way ANOVA (α=.05). RESULTS The highest transmittance was in the speed sintered, polished, nonthermocycled group, and the lowest transmittance was in the speed sintered, polished, thermocycled group (P=.029). The transmittance of the traditionally sintered, polished, nonthermocycled group was significantly higher than that in all the speed sintered, glazed groups; the traditionally sintered, glazed groups; and the traditionally sintered, polished, thermocycled group (P=.029). The transmittance of the traditionally sintered, polished, thermocycled group was significantly higher than that of all traditionally sintered, glazed groups (P=.029). The mean surface free energy in the traditionally sintered groups was higher than that in the speed sintered groups (P=.002); also, it was higher in the glazed groups than in the polished groups (P<.001). The aging process decreased surface free energy (P=.023). The mean surface roughness in the speed sintered groups was significantly lower than that in the traditionally sintered groups (P=.004). No significant difference in surface roughness was found between the polished and glazed groups and between the 2 variables of the aging process (P>.05). CONCLUSIONS Speed sintering and polishing may decrease the surface free energy and increase the translucency of the monolithic zirconia restoration. Also, speed sintering creates a smoother surface. Aging had a more significant effect on decreasing the surface free energy of the specimens and could make the least translucent restorations.
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Affiliation(s)
- Ali Hafezeqoran
- Associate Professor, Prosthodontics, Department of Prosthodontics, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, East Azerbaijan Province, Iran
| | - Pouya Sabanik
- Private practice, Tabriz, East Azerbaijan Province, Iran.
| | - Roodabeh Koodaryan
- Associate Professor, Prosthodontics, Department of Prosthodontics, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, East Azerbaijan Province, Iran
| | - Kambiz M Ghalili
- Clinical Professor, Prosthodontics, Department of Prosthodontics, College of Dentistry, New York University, New York City, NY; Private practice, New York City, NY
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Fouda AM, Stawarczyk B, Özcan M, Singer L, Bourauel C. Impact of glazing on wear, fracture load, and optical properties of a new fully crystallized lithium disilicate ceramic material. J Mech Behav Biomed Mater 2023; 146:106102. [PMID: 37660448 DOI: 10.1016/j.jmbbm.2023.106102] [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: 07/07/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/05/2023]
Abstract
OBJECTIVES Lithium disilicate (LDS) based glass ceramics are indispensable materials in the field of prosthetic dentistry due to their strength and excellent esthetics. Recently, novel fully crystallized LDS for the milling process have been introduced to the market, requiring only chairside polishing before delivery. Since limited data is available about subjecting this material to glazing, this study aimed to evaluate the wear properties, fracture resistance, and optical properties of the newly introduced fully crystallized LDS after glazing. METHODS Lithium disilicate glass-ceramics (fully crystallized (LiSiCAD) and partially crystallized types (EmaxCAD), of shade A3, were used in the present study. The fully crystallized specimens were subjected to a glazing firing cycle in a furnace (LiSiCAD-G) and compared to a polished fully crystallized counterpart (LiSiCAD-P, negative control) and a glazed partially crystallized LDS (EmaxCAD, positive control). Rectangular-shaped ceramic specimens (n = 10, 12 × 6.5 × 1.5 mm) and enamel antagonists were used to test the wear resistance in a specially designed wear machine built at the Department of Oral Technology, University of Bonn, Germany. The volumetric enamel loss of antagonists was measured by means of overlapping virtual 3D models derived from micro-CT scans for the teeth before and after the wear test. The weight loss of ceramic specimens in milligrams was measured after 100,000 and 200,000 wear cycles. A spectrophotometer was used to calculate the CIELAB color parameters of the ceramic specimens against black and white backgrounds to measure the translucency. Fracture resistance was also assessed after thermodynamic fatigue using a universal testing machine until fracture at a 1 mm/min crosshead speed. Statistical analysis was performed using one-way ANOVA and the significance level was set at α = 0.05. RESULTS EmaxCAD and LisiCAD-G groups showed significantly higher mean ceramic weight loss after 100,000 cycles (2 ± 0.3 mg and 1.93 ± 0.2 mg, respectively) than LisiCAD-P group (0.78 ± 0.19 mg). Glazed LiSiCAD specimens demonstrated significantly higher ΔE values from shade A3 compared to polished LiSiCAD. There was no significant difference in ΔE between LiSiCAD-G and EmaxCAD. For fracture resistance, no significant difference was observed between LiSiCAD-G and LiSiCAD-P before or after aging. CONCLUSIONS The glazed fully crystallized LDS was superior to the partially crystallized one with regard to wear resistance but showed more color changes than the polished fully crystallized one. Furthermore, polishing of fully crystallized LDS could still be considered a better option than glazing when aesthetics is a primary prerequisite.
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Affiliation(s)
- Ahmed Mahmoud Fouda
- Department of Oral Technology, Medical Faculty, University Hospital Bonn, 53111, Bonn, North Rhine-Westphalia, Germany; Department of Fixed Prosthodontics, Suez Canal University, Ismailia, Egypt.
| | - Bogna Stawarczyk
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Munich, Germany
| | - Mutlu Özcan
- University of Zurich, Center for Dental Medicine, Clinic of Chewing Function Disturbances and Dental Biomaterials, Zurich, Switzerland
| | - Lamia Singer
- Department of Oral Technology, Medical Faculty, University Hospital Bonn, 53111, Bonn, North Rhine-Westphalia, Germany; Department of Orthodontics, Medical Faculty, University Hospital Bonn, 53111, Bonn, North Rhine-Westphalia, Germany
| | - Christoph Bourauel
- Department of Oral Technology, Medical Faculty, University Hospital Bonn, 53111, Bonn, North Rhine-Westphalia, Germany
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Barreto LAL, Grangeiro MTV, Prado PHCO, Bottino MA, Dal Piva AMDO, Ramos NDC, Tribst JPM, Junior LN. Effect of Finishing Protocols on the Surface Roughness and Fatigue Strength of a High-Translucent Zirconia. Int J Dent 2023; 2023:8882878. [PMID: 37780934 PMCID: PMC10541300 DOI: 10.1155/2023/8882878] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 08/16/2023] [Accepted: 08/29/2023] [Indexed: 10/03/2023] Open
Abstract
Purpose In case of need for esthetical improvement of zirconia restorations, an individualization using extrinsic staining can be applied. This study aimed to evaluate the surface roughness and fatigue strength (survival) of high-translucency zirconia (3Y-TZP, YZ®HT, Vita Zanhfabrik) with extrinsic characterization and/or glaze. Methods Sixty (60) zirconia discs (12 × 1.2 mm) were obtained, sintered, and randomly distributed among three groups (n = 20) according to the surface finishing protocol: C (control), C + G (extrinsic characterization followed by a glaze layer), and G (glaze layer). The surface roughness (Ra) was analyzed with a contact profilometer. Subsequently, the specimens were subjected to a fatigue load profile starting at 120 N during 20,000 cycles at 4 Hz frequency, with a 5% increase at each step until failure. The failed specimens were evaluated under a stereomicroscope. Surface roughness analysis was evaluated by using one-way ANOVA and post hoc Tukey tests (95%); while fatigue survival probability was analyzed with Kaplan-Meier and Mantel-Cox (log- rank, 95%). Results One-way ANOVA revealed that surface roughness was affected by the finishing protocol, where C + G showed the highest mean value (0.46 ± 0.18 µm)A followed by G (0.30 ± 0.10 µm)B, and C (0.19 ± 0.02 µm)C. While for fatigue strength, the G protocol presented a higher mean value (243.00, and 222.36-263.63)A, followed by C + G (192.75 and 186.61-198.88)B and C (172.50 and 159.43-185.56)C. Conclusion Surface finishing protocols modify the surface roughness and fatigue strength of high-translucent zirconia. Regardless of the surface roughness, both glazing protocols improved the ceramic fatigue strength, favoring the restoration's long-term survival.
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Affiliation(s)
- Larissa Araújo Lopes Barreto
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), Eng. Francisco José Longo Avenue, 777, São José dos Campos, SP, Brazil
| | - Manassés Tercio Vieira Grangeiro
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), Eng. Francisco José Longo Avenue, 777, São José dos Campos, SP, Brazil
| | - Pedro Henrique Condé Oliveira Prado
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), Eng. Francisco José Longo Avenue, 777, São José dos Campos, SP, Brazil
| | - Marco Antonio Bottino
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), Eng. Francisco José Longo Avenue, 777, São José dos Campos, SP, Brazil
| | - Amanda Maria de Oliveira Dal Piva
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, Netherlands
| | - Nathalia de Carvalho Ramos
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), Eng. Francisco José Longo Avenue, 777, São José dos Campos, SP, Brazil
| | - João Paulo Mendes Tribst
- Department of Reconstructive Oral Care, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, Netherlands
| | - Lafayette Nogueira Junior
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), Eng. Francisco José Longo Avenue, 777, São José dos Campos, SP, Brazil
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Pongtongkham P, Pleumsamran N, Suttiat K. Effect of CAD/CAM Position and Thickness of Ultra-Translucent Multilayered Zirconia on Color Aspects. Int J Dent 2023; 2023:5000800. [PMID: 37635898 PMCID: PMC10460285 DOI: 10.1155/2023/5000800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 07/20/2023] [Accepted: 07/27/2023] [Indexed: 08/29/2023] Open
Abstract
Background Ultra-translucent multilayered zirconia restorations fabricated using computer-aided design and computer-aided manufacturing (CAD/CAM) technology have recently gained popularity. Their esthetic appeal is crucially dependent on the color accuracy, influenced by prosthesis thickness and multilayer composition due to CAD/CAM milling positions. This study comprehensively investigated how these two factors impacted color accuracy, thereby enhancing our understanding of color outcomes. Materials and Methods One hundred monolithic multilayer zirconia specimens with 10 × 10 mm square shape were milled in four different positions and five different thicknesses (1.0, 1.5, 2.0, 2.5, and 3.0 mm). The specimens were placed on an A3 shade resin composite substrate, and CIELAB values (L ∗, a ∗, and b ∗) were measured using a spectrophotometer. Delta E (ΔE) values were calculated to quantify the color differences between the specimens and the A3 VITA classical shade tab and compared with the perceptibility and acceptability thresholds of ΔE = 1.2 and 2.7, respectively. Pearson correlation, two-way ANOVA, and Tukey multiple comparisons (α = 0.05) were performed. Results The proportion of the dentin layer was positively correlated with the a ∗ and b ∗ values, while specimen thickness was positively correlated with the a ∗ value and negatively correlated with the L ∗ and b ∗ values. Significant difference in ΔE value due to different CAD/CAM positions was not observed within the same specimen thickness. Perceptible color differences were observed in specimens with thicknesses greater than 1 mm, while specimens with 1 mm thickness fell within the clinically acceptable range. Highest ΔE value was found in the specimen with 1 mm thickness. Conclusions Different compositions of multilayers in the final restoration due to different CAD/CAM positions do not significantly affect the color appearance of ultra-translucent multilayer zirconia, with color only influenced by specimen thickness.
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Affiliation(s)
- Palanupap Pongtongkham
- Department of Prosthodontics, Faculty of Dentistry, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Nathawat Pleumsamran
- Department of Prosthodontics, Faculty of Dentistry, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Kullapop Suttiat
- Department of Prosthodontics, Faculty of Dentistry, Chiang Mai University, Chiang Mai 50200, Thailand
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13
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Wu Z, Tian J, Wei D, Zhang Y, Lin Y, Di P. Effects of thickness and polishing treatment on the translucency and opalescence of six dental CAD-CAM monolithic restorative materials: an in vitro study. BMC Oral Health 2023; 23:579. [PMID: 37598167 PMCID: PMC10440033 DOI: 10.1186/s12903-023-03299-y] [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: 06/19/2023] [Accepted: 08/10/2023] [Indexed: 08/21/2023] Open
Abstract
BACKGROUND Computer-aided design and computer-aided manufacturing (CAD-CAM) materials for prosthetic is gaining popularity in dentistry. However, limited information exists regarding the impact of thickness and roughening treatment on the optical properties of contemporary CAD-CAM restorative materials. This study aimed to quantitatively evaluate the translucency and opalescence of six dental CAD-CAM materials in response to different thicknesses and roughening treatments. METHODS Six dental CAD-CAM materials, lithium disilicate glass-ceramic (IPS e.max CAD, LS), polymer-infiltrated ceramic (VITA Enamic, VE), resin-nano ceramic glass-ceramic (LAVA Ultimate, LU), polymethyl methacrylate (Telio CAD, TE), and two zirconia reinforced lithium silicate (VITA Suprinity, VS, and Celtra Duo, CD), in shade A2 were prepared as 12 × 12mm2 specimens of four thicknesses (0.5mm, 1.0mm, 1.5mm, and 2.0mm) (N = 240, n = 10). After three different treatments (polished, roughened by SiC P800-grit, and SiC P300-grit), the translucency parameter (TP00) and opalescence parameter (OP) were measured with a spectrophotometer (VITA Easyshade V). The surface roughness was analyzed with a shape measurement laser microscope. The data were analyzed using a MANOVA, post hoc Tukey-Kramer test, the t test, and regression analysis (α = .05). RESULTS The TP00 and OP were significantly influenced by material type, thickness and roughening treatment (P < .05). TP00 showed a continues decline with increasing thicknesses, while the variations of OP were material-dependent. TP00 ranged from 37.80 (LS in 0.5mm) to 5.66 (VS in 2.0mm), and OP ranged from 5.66 (LU in 0.5mm) to 9.55 (VS in 0.5mm). The variations in TP00 of all materials between adjacent thicknesses ranged from 2.10 to 15.29, exceeding the acceptable translucency threshold except for LU. Quadratic and logarithmic regression curves exhibited the best fit for TP00 among the materials. Compared to polished specimens, rougher specimens exhibited lower TP00 and higher OP in all materials except for LS (P < 0.05). Roughening with P300-grit decreased TP00 and OP by an average of 2.59 and 0.43 for 0.5mm specimens, and 1.26 and 0.25 for 2.0mm specimens, respectively. CONCLUSIONS Variations in translucency caused by thickness and roughening treatment were perceptible and may be clinically unacceptable. Careful consideration should be given to the selection of CAD-CAM materials based on their distinct optical properties.
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Affiliation(s)
- Zhengda Wu
- Department of Implantology, Peking University School and Hospital of Stomatology, 22 South Zhongguancun Avenue, Haidian District, Beijing, 100081, China
| | - Jiehua Tian
- Department of Implantology, Peking University School and Hospital of Stomatology, 22 South Zhongguancun Avenue, Haidian District, Beijing, 100081, China
| | - Donghao Wei
- Department of Implantology, Peking University School and Hospital of Stomatology, 22 South Zhongguancun Avenue, Haidian District, Beijing, 100081, China
| | - Yifan Zhang
- Department of Implantology, Peking University School and Hospital of Stomatology, 22 South Zhongguancun Avenue, Haidian District, Beijing, 100081, China
| | - Ye Lin
- Department of Implantology, Peking University School and Hospital of Stomatology, 22 South Zhongguancun Avenue, Haidian District, Beijing, 100081, China
| | - Ping Di
- Department of Implantology, Peking University School and Hospital of Stomatology, 22 South Zhongguancun Avenue, Haidian District, Beijing, 100081, China.
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Han JS, Yoon HI. Effect of translucency of CAD-CAM ceramic restorative materials and scanning aid conditions on the accuracy of intraoral scans. J Dent Sci 2023; 18:1212-1218. [PMID: 37404663 PMCID: PMC10316660 DOI: 10.1016/j.jds.2023.03.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 03/23/2023] [Indexed: 07/06/2023] Open
Abstract
Background/purpose Subsurface scattering from translucent material would affect the digital scans. This study aimed to evaluate the effect of translucency of ceramic restorative materials and scanning aid conditions on the accuracy of intraoral scans. Materials and methods Identical anatomic contour crowns with ten ceramic restorative materials were fabricated: five zirconia, three lithium disilicate glass-ceramic, and two leucite reinforced glass-ceramic. The models with ceramic crowns were digitized with an intraoral scanner (IOS) and analyzed for accuracy (n = 10) with and without a scanning aid. Scan time efficiency was recorded. Square-shaped specimens with 1.0-mm thickness were fabricated with the same materials, and translucency parameter (TP) values were measured. One-way ANOVA, Welch ANOVA, and a post-hoc pairwise comparison or independent t-test were used for trueness and time analysis, and the F-test was used to examine the precision (α = 0.05). Pearson correlation test was conducted. Results Significant differences were revealed for trueness with no scanning aid condition and for TP values (P < 0.05). In contrast, no statistically significant differences were observed for trueness with a scanning aid. A strong correlation (r = 0.854, P < 0.01) between TP value and trueness with no scanning aid was revealed. By applying a scanning aid, trueness was improved and scan time efficiency significantly increased (P < 0.05). Conclusion The translucency of ceramic restorative materials negatively affects the accuracy of IOS scan without a scanning aid; however, the scan accuracy and time efficiency of IOS scanning for ceramic restorations can be improved by applying scanning aid, and prostheses with high quality without unnecessary labor can be produced.
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Affiliation(s)
| | - Hyung-In Yoon
- Corresponding author. Department of Prosthodontics, Seoul National University School of Dentistry and Dental Research Institute, 101, Daehak-ro, Jongro-gu, Seoul, 03080, Republic of Korea.
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15
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Lee WF, Takahashi H, Iwasaki N, Peng PW. Effect of thickness of externally characterized stains on optical properties of high-translucency zirconia. Clin Oral Investig 2023; 27:165-171. [PMID: 36125622 DOI: 10.1007/s00784-022-04704-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 08/29/2022] [Indexed: 01/28/2023]
Abstract
OBJECTIVES There is insufficient information about the effects of the thickness of externally characterized stains or glazes on CIELAB color parameters and the translucency parameter (TP) of 5 mol% yttria partially stabilized zirconia (5Y-PSZ). The present study evaluated the effect of a thickness reduction of the externally characterized or glazed layer on its CIE2000 color parameters and TP00 of 5Y-PSZ. MATERIALS AND METHODS Twenty-eight specimens were sectioned from 5Y-PSZ blanks. Three brands of powdered stains (namely VI, SH, and IV) and a glaze (GL) were used to extrinsically stain the specimen surfaces (n = 7 per group). After measuring the final thickness and color, specimens of each group were carefully ground and finally polished. The reduced thickness was carefully controlled in decrements of 0.02 mm on the characterized stains or glazed layers at each reduction cycle until the surface of the un-stained zirconia was exposed. The CIELAB color parameters of specimens were measured using a spectrophotometer. Subsequently, differences in lightness (∆L'), chroma (∆C'), and hue (∆H'), and TP00 values and color differences (ΔE00) were calculated using the CIEDE2000 formula to determine differences between the specimen and the un-stained zirconia at each reduction cycle. A paired-samples t-test, two-way mixed-design analysis of variance, and Pearson correlation coefficient were used to analyze the data (α = 0.05). RESULTS There were no significant differences in lightness, chroma, hue, or TP00 values before or after glazing or after each reduction cycle of the glazed layer. Mean ΔE00 values ranged between 20.94 and 33.55 after applying the externally characterized stains. With a decreased thickness of the characterized stain layer, there were observed that significant decreases in ∆L', ∆H', ∆C', and ΔE00, and significant increases in TP00. CONCLUSIONS Increasing the thickness of externally characterized stains decreased the lightness and caused the alternation of chroma and hue, whereas these phenomena were not observed in the glazed group. There was a slight change of CIE2000 color parameters and TP00 when the thickness of the characterized layer exceeded 0.06 mm. CLINICAL RELEVANCE The application and thickness of externally characterized stains can sensitively affect CIE2000 color parameters and translucency of 5Y-PSZ.
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Affiliation(s)
- Wei-Fang Lee
- School of Dental Technology, Taipei Medical University, Taipei, 11031, Taiwan
| | - Hidekazu Takahashi
- School of Oral Health Engineering, Faculty of Dentistry, Tokyo Medical and Dental University, Tokyo, 113-8549, Japan
| | - Naohiko Iwasaki
- School of Oral Health Engineering, Faculty of Dentistry, Tokyo Medical and Dental University, Tokyo, 113-8549, Japan
| | - Pei-Wen Peng
- School of Dental Technology, Taipei Medical University, Taipei, 11031, Taiwan.
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Singh RG, Lyons KM, Waddell JN, Li KC. Effect of thermocycling on the mechanical properties, inorganic particle release and low temperature degradation of glazed high translucent monolithic 3Y-TZP dental restorations. J Mech Behav Biomed Mater 2022; 136:105495. [PMID: 36208582 DOI: 10.1016/j.jmbbm.2022.105495] [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: 08/22/2022] [Revised: 09/27/2022] [Accepted: 09/27/2022] [Indexed: 11/24/2022]
Abstract
The influence of thermocycling on the surface deterioration of glazed monolithic high translucent 3Y-TZP dental restorations is still unclear. The purpose of this study therefore was to evaluate low temperature degradation (LTD), elemental release and surface degradation pattern after five years of simulated clinical time. A total of 123 specimens were prepared from second-generation high translucent 3Y-TZP as per ISO 6872:2015 standards (3 mm × 4 mm × 30 mm). They were classified as per glazing and thermocycling protocol; group CPT, DGT and IGT. Glaze materials were applied on one surface of the specimen and subjected to a thermocycling in artificial saliva, four-point bending test, inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX) and x-ray diffraction (XRD). Flexural strength, characteristic strength and Weibull modulus values were derived from four-point bending test. Descriptive fractographic analysis of surfaces was conducted to observe the surface degradation characteristics and point of failure. Control/no glaze with thermocycling (CPT = 621.5, 1σ = 117.0 MPa) presented higher flexural strength values compared to glaze I with thermocycling (442.4, 1σ = 45.4 MPa) and glaze II with thermocycling (534.3, 1σ = 46.3 MPa). Characteristic strength from Weibull analysis also observed higher values (669.2 MPa) for the control specimens. XRD analysis showed that monoclinic volume fraction (Vm = 11.0, 1σ = 0.7%) was highest in control specimens. Fractographic analysis suggested that there was no correlation between the point of failure initiation and mean flexural strength values. Glazing protected the high translucent 3Y-TZP surface against LTD during thermocycling but negatively impacted on the flexural strength.
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Affiliation(s)
- Raj Gaurav Singh
- Department of Oral Rehabilitation, Faculty of Dentistry, University of Otago, New Zealand.
| | - Karl Michael Lyons
- Department of Oral Rehabilitation, Faculty of Dentistry, University of Otago, New Zealand.
| | - John Neil Waddell
- Department of Oral Rehabilitation, Faculty of Dentistry, University of Otago, New Zealand.
| | - Kai Chun Li
- Department of Oral Rehabilitation, Faculty of Dentistry, University of Otago, New Zealand.
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Li S, Zhang X, Xia W, Liu Y. Effects of surface treatment and shade on the color, translucency, and surface roughness of high-translucency self-glazed zirconia materials. J Prosthet Dent 2022; 128:217.e1-217.e9. [PMID: 35817621 DOI: 10.1016/j.prosdent.2022.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 11/28/2022]
Abstract
STATEMENT OF PROBLEM The impact of different surface treatments and shades on the color, translucency, and surface roughness of high-translucency self-glazed zirconia materials is unclear. PURPOSE The purpose of this in vitro study was to investigate the effects of different external surface treatments (self-glazed, milled, polished, and glazed), intaglio surface treatments (milled and airborne-particle abraded), and shades (A1 and A3 shades) on the color, translucency, and surface roughness of high-translucency self-glazed zirconia materials, as well as the correlations among optical parameters, translucency, and surface roughness. MATERIAL AND METHODS Eighty shade A1 and 80 shade A3 disks were fabricated with a thickness of 0.80 ±0.02 mm and divided into 16 groups (n=10). Different external and intaglio surface treatments were applied to the specimens. CIELab values were measured with a spectrophotometer, and color differences (ΔE00) and relative translucency parameter (RTP) were calculated. Total transmittance (Tt%) and reflectance (R%) were tested with a spectrophotometer equipped with an integrating sphere. Surface roughness (Ra and Rz) (μm) was measured with a noncontact 3-dimensional laser scanning microscope. One specimen from each group was subjected to scanning electron microscope (SEM) examination. Data were analyzed with ANOVA and the Tukey post hoc test. The correlation among optical parameters, translucency, and surface roughness was investigated by using Pearson correlation analysis (α=.05). RESULTS The effects of external surface treatments, intaglio airborne-particle abrasion, and shades on ΔE00, RTP, and Ra values of the disks were significantly different (P<.001). The smoothest external polishing surface had the greatest RTP and color difference (P<.001). Shade A3 disks had lower RTP and Tt% values than shade A1 disks (P<.001). ΔE00 had a highly positive relationship with the RTP (A1: r=0.884, P<.001; A3: r=0.859, P<.001). SEM images demonstrated that surface treatments affected the surface texture of monolithic zirconia ceramics. CONCLUSIONS Different surface treatments affected the surface roughness, translucency, and final color of zirconia materials. The smoothest external polishing surface had the greatest RTP and color difference. Different shades influenced the translucency, as the darker the disk shade, the lower the translucency. The RTP was appropriate as an auxiliary indicator for evaluating the color of a dental ceramic.
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Affiliation(s)
- Siyu Li
- Assistant Professor, Department of General Dentistry, Peking University School and Hospital of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Beijing, PR China
| | - Xinyue Zhang
- Engineer, Center of Digital Dentistry, Peking University School and Hospital of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Beijing, PR China
| | - Wei Xia
- Associate Professor, Department of Engineering Science, Uppsala University, Uppsala, Sweden
| | - Yihong Liu
- Associate Professor, Department of General Dentistry, Peking University School and Hospital of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Beijing, PR China.
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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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Al-Wahadni AM, Abu Al-Addous AM, Nattress BR, Jum'ah A. Color Changes Associated with Sandblasting, Hydrofluoric Acid Etching, and Er:YAG Laser Irradiation of Milled Feldspathic Porcelain Laminate Veneers. Oper Dent 2022; 47:330-336. [PMID: 35604832 DOI: 10.2341/20-213-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/19/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVES To evaluate color changes in milled feldspathic porcelain laminate veneers following hydrofluoric acid etching (HFA), sandblasting (SB), or Er:YAG laser irradiation (LI). METHODS AND MATERIALS Disc-shaped specimens (thickness=1 mm, diameter=8 mm) were milled from feldspathic porcelain blocks (n=40). Glazed specimens were randomly assigned to four subgroups (n=10 each) according to surface treatment: negative control, HFA, SB, and LI. A layer of translucent, light-cured resin cement (thickness=0.1 mm) was then applied following silanization. The color was characterized by the L*, a*, and b* uniform color space (CIE) using a reflection spectrophotometer. CIEDE2000 (ΔE00) was calculated to determine the color difference between each surface treatment and negative control groups. Data were statistically analyzed using analysis of variance (ANOVA), Kruskal-Wallis, and Dunn-Bonferroni post hoc tests. RESULTS There were no significant differences in CIEL* and CIEb* coordinates between negative control and all surface treatment groups (p≥0.108). The SB group demonstrated significantly lower mean CIEa* (higher greenish hue) compared to other groups (p≤0.003). HFA exhibited significantly higher CIEa* (closer to red) when compared to LI (p=0.039). LI induced the smallest overall color change compared to negative control (ΔE00=1.43 [1.07]). However, the differences in ΔE00 values were not statistically significant (p=0.648). CONCLUSIONS The tested surface treatments did not affect the lightness or the yellowness of the 1-mm-thick milled feldspathic porcelain veneers. However, sandblasting resulted in a significant increase in the greenish hue. The Er:YAG laser resulted in the closest ΔE00 (1.43) to the 50:50% perceptibility threshold (ΔE00=1.2).
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Affiliation(s)
- A M Al-Wahadni
- Ahed M Al-Wahadni, BDS, MDSC, PhD (Clin), FFDRCSI, FDSRCPSG, professor of prosthodontics, Faculty of Dentistry, Jordan University of Science and Technology, Irbid, Jordan
| | - A M Abu Al-Addous
- Ahmad M Abu Al-Addous, BDS, MClinDent, specialist prosthodontist, Private Dental Practice, Amman, Jordan
| | - B R Nattress
- Brian R. Nattress, BChD, PhD, MRD RCSEd, FDS RCSEd, FFDTEd, professor of restorative dentistry, Division of Restorative Dentistry, School of Dentistry, University of Leeds, Leeds, UK
| | - A Jum'ah
- *Ahmad A Jum'ah, BDS, MSc, MRD RCSEd, PhD (Clin), department chair, associate professor, and consultant of Restorative Dentistry, Faculty of Dentistry, Jordan University of Science and Technology, Irbid, Jordan
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20
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Manziuc MM, Gasparik C, Burde AV, Ruiz-López J, Buduru S, Dudea D. Influence of manufacturing technique on the color of zirconia restorations: Monolithic versus layered crowns. J ESTHET RESTOR DENT 2022; 34:978-987. [PMID: 35297153 DOI: 10.1111/jerd.12897] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/17/2022] [Accepted: 02/20/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVES The study aimed to compare the color of monolithic and layered zirconia crowns fabricated using different brands in the cervical, middle, and incisal areas. MATERIALS AND METHODS A total of 45 crowns were fabricated from three brands (Katana, Nacera, Cercon) using three methods (monolithic = ML (n=5), cut-back + enamel = BL (n=5), cut-back + dentin + enamel = TL (n=5)). CIE L*, a* b*, C*, h° color coordinates were recorded with a dental spectrophotometer in cervical, middle, and incisal areas. Color differences between manufacturing techniques, tooth areas, and brands were calculated using the CIEDE2000(1:1:1) formula, and the values were compared to the perceptibility (PT00 ) and acceptability thresholds (AT00 ). Comparisons between color coordinates were analyzed statistically (Kruskal-Wallis and Mann-Whitney U tests, p < 0.001). RESULTS Significant differences were found between CIE L*, a*, b*, C*, h° coordinates of the zirconia crowns (p < 0.001), generally. The lowest color differences were obtained between BL and TL crowns in cervical and middle areas. Color differences between cervical and middle areas were mostly below PT00 . An acceptable color difference was found between Katana and Cercon crowns. CONCLUSIONS The manufacturing technique and the brand influenced the color of zirconia crowns. Also, the color of the crowns varied from cervical to incisal. CLINICAL SIGNIFICANCE Reproducing the optical properties of teeth with ceramic crowns might be challenging, given the differences in the internal configuration of the enamel and dentine, as well as their complex behavior when interacting with light. When deciding whether to fabricate a monolithic crown in translucent zirconia or improve its appearance by layering with more translucent glass-ceramic, the clinicians and dental technicians must be aware of these procedures' effect on the final color of the restorations.
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Affiliation(s)
- Manuela Maria Manziuc
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Cristina Gasparik
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Alexandru Victor Burde
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Javier Ruiz-López
- Department of Optics, University of Granada, Campus Fuente Nueva, Granada, Spain
| | - Smaranda Buduru
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Diana Dudea
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
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Hajhamid B, Alfrisany N, Somogyi-Ganss E. The effect of accelerated aging on crystalline structures and optical properties of different monolithic zirconia: A qualitative systematic review. Dent Mater 2022; 38:569-586. [DOI: 10.1016/j.dental.2022.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 02/14/2022] [Indexed: 11/03/2022]
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Lee WF, Iwasaki N, Peng PW, Takahashi H. Effect of toothbrushing on the optical properties and surface roughness of extrinsically stained high-translucency zirconia. Clin Oral Investig 2021; 26:3041-3048. [PMID: 34845525 DOI: 10.1007/s00784-021-04287-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 11/01/2021] [Indexed: 12/17/2022]
Abstract
OBJECTIVES The effect of toothbrushing on the color, relative translucency, and surface roughness of extrinsically stained zirconia dental restorations is still unclear. The purpose of the present study was to evaluate the optical properties and surface textures of extrinsically stained or glazed partially stabilized zirconia with 5 mol% yttria (5Y-PSZ) after toothbrushing by determining changes in the color, translucency parameter (TP), and surface roughness. MATERIALS AND METHODS Specimens (2 mm thick; n = 50) were sectioned from 5Y-PSZ blanks. Three brands of powdered stains (namely VI, SH, IV) and a glaze (GL) were used to extrinsically stain the specimen surfaces (n = 10 per group). The specimens were subjected to 10,000-50,000 simulated toothbrushing strokes using a toothpaste slurry (Ora2 PREMIUM Stain clear paste). The color parameters were measured before staining or glazing and before and after simulated brushing. The color changes and TP values can be calculated before and after simulated brushing. The surface roughness was also evaluated. RESULTS Significant changes were found in the shade and TP values of 5Y-PSZ after extrinsic staining, but no significant changes were found after toothbrushing, irrespective of the staining brand (p > 0.05). The surface roughness of the characterized 5Y-PSZ specimens decreased after toothbrushing, whereas that of the non-characterized 5Y-PSZ group increased. CONCLUSIONS Toothbrushing markedly affects the surface roughness of extrinsically stained or glazed 5Y-PSZ specimens, whereas no impacts on the color or translucency were observed. CLINICAL RELEVANCE For esthetic reasons, clinicians and dental technicians prefer to apply extrinsic stains to zirconia restorations, which profoundly affects its appearance. The limited influence of toothbrushing on color and translucency of 5Y-PSZ is promising for clinical applications.
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Affiliation(s)
- Wei-Fang Lee
- School of Dental Technology, Taipei Medical University, Taipei, 11031, Taiwan
| | - Naohiko Iwasaki
- Department of Oral Biomaterials Development Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, 113-8549, Japan
| | - Pei-Wen Peng
- School of Dental Technology, Taipei Medical University, Taipei, 11031, Taiwan.
| | - Hidekazu Takahashi
- Department of Oral Biomaterials Development Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, 113-8549, Japan.
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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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Manziuc MM, Gasparik C, Burde AV, Dudea D. Color and masking properties of translucent monolithic zirconia before and after glazing. J Prosthodont Res 2021; 65:303-310. [PMID: 33116028 DOI: 10.2186/jpr.jpr_d_20_00039] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Purpose 1. to assess the ability of four brands of translucent monolithic zirconia with different thicknesses to mask discolored substrates; 2. to assess the influence of glazing upon their color coordinates and masking properties.Methods Sixty samples of shade A1 (0.8, 1.5, and 2.0 mm thickness) from: ZirCAD/MT, Katana/HT, Vita YZ/HT, Cercon/HT were fabricated and glazed using a standardized laboratory procedure. CIE L*a*b* parameters were recorded on composite substrates, (IPS Natural Die Material Kit) (ND1=reference; ND2, ND3, ND4, ND5=test backgrounds), before and after glazing. The color changes of zirconia samples induced by glazing were analyzed. Masking properties was calculated as the color difference between CIE L*a*b* parameters of the samples placed on reference and test substrates with CIEDE2000(1:1:1) formula. The effect of material, thickness, substrate, and glazing on the color of monolithic zirconia was analyzed with ANOVA test and the multiple comparisons were analyzed with Tukey HSD tests (α=0.05).Results After glazing, lightness L* significantly increased, while chromatic coordinates a* and b* decreased (p<0.05). Significant differences in the masking properties of the four materials (p<0.001) were found, with IPS e.max ZirCAD/MT having the lowest masking effect (p<0.001). Thickness, substrate and glazing had a significant effect on the color masking properties of monolithic zirconia (p<0.001).Conclusions Masking properties of translucent zirconia were significantly influenced by the materials, the thickness and the color of the substrate; moreover, glazing improved the masking ability for all zirconia samples.
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Affiliation(s)
- Manuela Maria Manziuc
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Cristina Gasparik
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Alexandru Victor Burde
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Diana Dudea
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
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Li X, Wang Q, Qiu X, Zhao B. Effect of different CAD/CAM cutting depths on the post-fatigue load-bearing capacity of novel multilayer zirconia restorations. J Dent 2021; 111:103709. [PMID: 34062215 DOI: 10.1016/j.jdent.2021.103709] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/22/2021] [Accepted: 05/25/2021] [Indexed: 10/21/2022] Open
Abstract
OBJECTIVES To investigate the post-fatigue load-bearing capacity of restorations milled at various cutting depths in a novel strength- and color-gradient multilayer zirconia CAD/CAM disk. METHODS Identical crowns were divided into 4 groups (n = 25 per group): crowns milled at 3 CAD/CAM cutting depths in multilayer zirconia disks as 3 experiment groups and homogeneous zirconia crowns as a control group. The color differences between various cutting depths were measured. In each group, crowns were tilted at 15° and subjected to fatigue loading for various numbers of cycles (0, 106, 2 × 106, 3 × 106 or 4 × 106, n = 5 per subgroup). All surviving crowns were subsequently submitted to a static fracture test to determine load-bearing capacity. The data were analyzed by ANOVA and Weibull distribution analysis. Failure modes were observed with SEM. RESULTS For a novel multilayer zirconia, a deeper CAD/CAM cutting depth corresponded to a higher load-bearing capacity but a darker color. After 106 cycles of fatigue loading, there was not a significant reduction in fracture load. However, after 4 × 106 cycles, the load-bearing capacity of all crowns decreased significantly by approximately 50%. For multilayer and homogeneous zirconia materials, similar failure mode and Weibull modulus were identified. CONCLUSIONS Restorations can be milled at various CAD/CAM cutting depths in a novel multilayer zirconia disk depending on the durability and esthetic requirements. The load-bearing capacity of multilayer restorations degraded significantly after 4 × 106 cycles of fatigue loading, but not after 106 cycles. CLINICAL SIGNIFICANCE For a novel multilayer zirconia disk, a posterior restoration can be milled from the middle or bottom of the disk to improve its load-bearing capacity. For an anterior restoration, to meet the esthetic requirements, milling the entire thickness of a multilayer disk is recommended.
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Affiliation(s)
- Xuejing Li
- School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Qiang Wang
- School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China.
| | - Xiaohai Qiu
- Tianjin Stomatological Hospital, Nankai University, Tianjin, China
| | - Baohong Zhao
- School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China.
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Influence of coloring liquid immersion on flexural strength, Vickers hardness, and color of zirconia. J Prosthet Dent 2021; 126:589.e1-589.e6. [PMID: 33423819 DOI: 10.1016/j.prosdent.2020.11.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 11/13/2020] [Accepted: 11/16/2020] [Indexed: 11/23/2022]
Abstract
STATEMENT OF PROBLEM Zirconia is a widely used restorative material, yet its white color does not meet esthetic requirements and coloring is needed. However, the effects of different durations of coloring have not been thoroughly investigated. PURPOSE The purpose of this in vitro study was to evaluate the effects of coloring liquid immersion of different durations on the flexural strength, Vickers hardness, and color of zirconia. MATERIAL AND METHODS Fifty bar-shaped and 60 disk-shaped zirconia specimens were milled from nonshaded (Copran Zri) and preshaded (Copran Zri Precoloured Medium) disks by using a computer-aided design and computer-aided manufacturing (CAD-CAM) system. Preshaded specimens were assigned to the group PS and received no further immersion. Nonshaded specimens were divided into 4 subgroups as per immersion time in coloring liquid (Copran Color A2 Shade): control (C; no immersion), G45 (45 seconds of immersion), G90 (90 seconds of immersion), and G135 (135 seconds of immersion). Bar-shaped specimens were subjected to a 3-point flexural strength test by using a universal testing machine (Lloyd LRX), following the International Organization for Standardization (ISO) 6872:2015 specification. Color coordinates of disk-shaped specimens were measured with a spectrophotometer (VITA Easyshade Advance 4.0) over a gray background. Color differences were calculated by using both CIE76 and CIEDE2000 formulas, followed by a comparison of obtained values with perceptibility (CIE76: 3.7, CIEDE2000: 0.8) and acceptability (CIE76: 6.8, CIEDE2000: 1.8) thresholds of each formula. Subsequently, Vickers hardness measurements were conducted. The data were statistically analyzed by using the Shapiro-Wilk test, 1-way ANOVA, and the Tukey HSD test (α=.05). RESULTS Immersing zirconia specimens in coloring liquid decreased the flexural strength and hardness values, as group C presented the highest values for both parameters. In addition, prolonged duration had a negative effect on mechanical properties. The flexural strength of groups PS and G45 (P=.993) and groups G90 and G135 (P=.999) was statistically similar. For Vickers hardness, group G135 presented the lowest values with the difference between groups G90 and G135 being statistically similar (P=.061). Color differences among groups varied from 2.49 to 27.33 for ΔE∗, whereas ΔE00 values ranged from 0.58 to 8.26. Compared with group C, ΔE∗ values of all shaded specimens exceeded the acceptability threshold of 6.8. The color difference between each group was higher than the acceptability threshold values of both ΔE∗ and ΔE00 except for groups G45 and PS. CONCLUSIONS Colored zirconia specimens had lower flexural strength and Vickers hardness values than nonshaded specimens, regardless of the immersion time or coloring technique.
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Saker S, Özcan M. Effect of surface finishing and polishing procedures on color properties and translucency of monolithic zirconia restorations at varying thickness. J ESTHET RESTOR DENT 2020; 33:953-963. [PMID: 33188586 DOI: 10.1111/jerd.12681] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 10/12/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVE This study aimed to assess the impact of monolithic zirconia thickness on its color properties after different surface finishing and polishing procedures, and following aging in coffee solution. MATERIALS AND METHODS Two types of monolithic zirconia brands [Prettau Anterior (PA) and DD Cubex2 (DDC)] with three different thicknesses: 0.5, 1, and 1.5, and 10 mm diameter were tested. The color properties were evaluated after various surface finishing procedures (glazing, adjusting with burs + glaze, polishing, adjusting with burs + polishing) and after 5,000 cycles in a coffee solution were evaluated. The differences in color (ΔE) and translucency, were calculated and statistically analyzed by three-way ANOVA and pairwise comparison (α = 0.05). RESULTS The brand, material thickness, and surface finishing protocol before and after coffee thermocycling had significant effect on color variations (p < 0.001). For translucency, 3-way ANOVA revealed a significant interaction between the material thickness and surface finishing protocol following aging in coffee solution (p < 0.001), however no significant interaction was observed following the surface finishing protocols (p = 0.247). CONCLUSIONS The optical properties of monolithic zirconia ceramics can be influenced by the material brand, material thickness and the procedure of surface finishing and polishing. CLINICAL SIGNIFICANCE Clinicians should take into consideration the potential change of the color properties of monolithic zirconia restorations following both contouring and occlusal adjustment procedures and coffee intake.
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Affiliation(s)
- Samah Saker
- Department of Fixed Prosthodontics, Mansoura University, Mansoura, Egypt
| | - Mutlu Özcan
- Division of Dental Biomaterials, Center for Dental and Oral Medicine, Clinic for Reconstructive Dentistry, University of Zürich, Zürich, Switzerland
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Jum'ah AA, Brunton PA, Li KC, Waddell JN. Simulated clinical adjustment and intra-oral polishing of two translucent, monolithic zirconia dental ceramics: An in vitro investigation of surface roughness. J Dent 2020; 101:103447. [PMID: 32763368 DOI: 10.1016/j.jdent.2020.103447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/30/2020] [Accepted: 08/01/2020] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVE To assess the surface roughness and residual flaws in two translucent zirconia substrates following simulated clinical adjustment and intra-oral finishing/polishing. MATERIALS AND METHODS Specimens were prepared from two translucent (5Y-ZP/8Y-ZP) and one conventional (3Y-TZP) zirconia substrates (n = 84 p/g). Arithmetic mean roughness parameter (Ra) was determined for all experimental groups at four stages (n = 21 p/g): (1) as-sintered, (2) surface grinding using a zirconia cutting diamond bur, (3) polishing using 1-step, 2-step or 4-step intra-oral polishing kits, and (4) laboratory polishing/glazing. Scanning electron microscopy (SEM) was used to evaluate residual surface flaws. Data were statistically analysed using a two-way ANOVA test, multiple and pairwise comparisons were performed using a Bonferroni post hoc test. RESULTS Ra was significantly higher for as-sintered and ground 5Y-ZP/8Y-ZP compared to 3Y-TZP (p ≤ 0.001). Material type and polishing protocol had statistically significant effect on Ra (p < 0.001). The 4-step polishing resulted in the lowest Ra in 3Y-TZP/5Y-ZP (p ≤ 0.001). No significant differences were observed between different polishing protocols in 8Y-ZP (p≥0.655). Glazing significantly reduced Ra in all materials compared to other polishing protocols (p ≤ 0.001) except for the 4-step protocol in 3Y-TZP (p = 0.195). SEM revealed pronounced surface flaws in ground 5Y-ZP/8Y-ZP. Grinding of 3Y-TZP induced ductile material removal and thereby, minimal cohesive material loss. The 4-step polishing protocol resulted in the fewest and shallowest surface flaws in all groups. Glazing of 3Y-TZP resulted in the most homogenous surface contrary to 5Y-ZP/8Y-ZP. CONCLUSIONS The finest surface finish was achieved using the 4-step polishing protocol in all studied materials. This protocol might be inadequate however for polishing of ground 5Y-ZP/8Y-ZP as a result of the pronounced surface damage induced by the grinding process. The glazing of 5Y-ZP/8Y-ZP might not be as predictable as for 3Y-TZP. CLINICAL SIGNIFICANCE The higher susceptibility to surface damage, as a result of increasing dopant concentration, may render polishing of ground, translucent zirconia more complicated compared to the conventional 3Y-TZP counterparts.
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Affiliation(s)
- Ahmad A Jum'ah
- Jordan University of Science and Technology, Faculty of Dentistry, Department of Conservative Dentistry, Irbid 22110, Jordan.
| | - Paul A Brunton
- University of Otago, Faculty of Dentistry, 310 Great King Street, Dunedin 9016, New Zealand
| | - Kai Chun Li
- University of Otago, Faculty of Dentistry, 310 Great King Street, Dunedin 9016, New Zealand
| | - J Neil Waddell
- University of Otago, Faculty of Dentistry, 310 Great King Street, Dunedin 9016, New Zealand
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Tabatabaian F, Karimi M, Namdari M. Color match of high translucency monolithic zirconia restorations with different thicknesses and backgrounds. J ESTHET RESTOR DENT 2020; 32:615-621. [DOI: 10.1111/jerd.12596] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/19/2020] [Accepted: 05/04/2020] [Indexed: 11/29/2022]
Affiliation(s)
- Farhad Tabatabaian
- Department of ProsthodonticsSchool of Dentistry, Shahid Beheshti University of Medical Sciences Tehran Iran
| | | | - Mahshid Namdari
- Department of Community Oral HealthSchool of Dentistry, Shahid Beheshti University of Medical Sciences Tehran Iran
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Habibi Y, Dawid M, Waldecker M, Rammelsberg P, Bömicke W. Three‐year clinical performance of monolithic and partially veneered zirconia ceramic fixed partial dentures. J ESTHET RESTOR DENT 2020; 32:395-402. [DOI: 10.1111/jerd.12568] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 01/16/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Yasamin Habibi
- Department of Prosthetic DentistryUniversity Hospital Heidelberg, University of Heidelberg Heidelberg Germany
| | - Marie‐Theres Dawid
- Department of Prosthetic DentistryUniversity Hospital Heidelberg, University of Heidelberg Heidelberg Germany
| | - Moritz Waldecker
- Department of Prosthetic DentistryUniversity Hospital Heidelberg, University of Heidelberg Heidelberg Germany
| | - Peter Rammelsberg
- Department of Prosthetic DentistryUniversity Hospital Heidelberg, University of Heidelberg Heidelberg Germany
| | - Wolfgang Bömicke
- Department of Prosthetic DentistryUniversity Hospital Heidelberg, University of Heidelberg Heidelberg Germany
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Bittar BF, Miranda JS, Simões AC, de Carvalho Ramos N, Machado JPB, Zhang Y, Souza ROA, Leite FPP. Effect of extrinsic pigmentation and surface treatments on biaxial flexure strength after cyclic loading of a translucent ZrO 2 ceramic. Dent Mater 2019; 35:1644-1653. [PMID: 31575489 PMCID: PMC6858620 DOI: 10.1016/j.dental.2019.08.117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 08/12/2019] [Accepted: 08/31/2019] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the influence of extrinsic pigmentation on the biaxial flexural strength and surface topographic of translucent Y-TZP (InCoris TZI - Sirona - USA) subjected to several surface treatments. METHODS Sintered zirconia discs-shaped specimens (n=120) (ø:12mm; thickness:1.2mm; ISO 6872) were prepared and divided (n=15) according to various factors: "extrinsic pigmentation" (n: without; p: with) and "surface treatments" (C: control - as sintered; A: abraded with silica-coated alumina particles (30μm); G: glazed with a thin film of low-fusing porcelain glaze; GH: glazed and etched with 10% hydrofluoridric acid for 60s. Mechanical cycling (1.2×106 cycles, 200N, 3.8Hz) and flexural strength test (1mm/min - 1000kg cell) were performed. Two-way ANOVA and Tukey's were used for statistical test (α=0.05). Weibull analysis was used to evaluate the strength reliability. Samples were analyzed via (1) an optical profilometer to determine the surface roughness (Ra); (2) an X-ray diffraction (XRD) to evaluate phase transformations; and (3) a SEM equipped with an energy dispersive X-ray spectroscopy (EDX) to elucidate morphological properties and chemical compositions. RESULTS Regardless of the surface treatment (p=0.5459) (Cn: 560.16MPa; Gn: 573.36MPa; An: 643.51MPa; GHn: 542.94MPa; Cp: 628.04MPa; Gp: 641.90MPa; Ap: 554.47MPa; GHp :602.84MPa) and extrinsic pigmentation (p=0.1280) there was no difference in the flexural strength among the experimental groups. According to the XRD analysis, phase transformations occurred in the An group (t→m) and in Ap group (t→c). Surface roughness was affected by surface treatments (An - p=0.001) and extrinsic pigmentation (Gp - p=0.001). SIGNIFICANCE The biaxial flexural strength of the tested samples was not affected neither by surface treatments nor by pigmentation, although it can cause phase transformation and promote surface roughness.
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Affiliation(s)
- Breno Fortes Bittar
- Department of Restorative Dentistry, Federal University of Juiz de Fora (UFJF), Juiz de Fora/MG, Brazil
| | - Jean Soares Miranda
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University - UNESP, São José dos Campos, São Paulo, Brazil
| | - Arthur Chaves Simões
- Department of Restorative Dentistry, Federal University of Juiz de Fora (UFJF), Juiz de Fora/MG, Brazil
| | - Nathália de Carvalho Ramos
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University - UNESP, São José dos Campos, São Paulo, Brazil
| | - João P B Machado
- Federal University of Rio Grande do Norte/UFRN, Health Science Center, Department of Dentistry, Natal-RN/Brazil
| | - Yu Zhang
- New York University College of Dentistry, Department of Biomaterials and Biomimetics, 433 First Avenue, Room 810, New York, NY 10010, USA
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Häfner SJ. Puzzling mRNA: Alternative splicing fine-tunes specificity and function. Biomed J 2019; 42:137-140. [PMID: 31466707 PMCID: PMC6717781 DOI: 10.1016/j.bj.2019.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 11/03/2022] Open
Abstract
In this issue of the Biomedical Journal we discover how alternative splicing might modulate the cell-type specificity and exact function of a ubiquitous purinergic receptor and how the beta blocker propanolol can contribute to breast cancer therapy. Moreover, we learn which culture conditions generate the best vascularisation of tissue engineered bone and which are the clinical features of acute necrotising encephalopathy in adults. Other studies reveal, how laser irradiation can fix fractured all-ceramic dental restorations in situ, and finally that nuclear magnetic resonance holds great potential for the rapid detection of pathogens.
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Affiliation(s)
- Sophia Julia Häfner
- University of Copenhagen, BRIC Biotech Research & Innovation Centre, Anders Lund Group, Ole Maaløes Vej 5, 2200, Copenhagen, Denmark.
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