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Alghauli MA, Alqutaibi AY, Wille S, Kern M. The physical-mechanical properties of 3D-printed versus conventional milled zirconia for dental clinical applications: A systematic review with meta-analysis. J Mech Behav Biomed Mater 2024; 156:106601. [PMID: 38810545 DOI: 10.1016/j.jmbbm.2024.106601] [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: 01/21/2024] [Revised: 05/12/2024] [Accepted: 05/23/2024] [Indexed: 05/31/2024]
Abstract
AIM OF STUDY This systematic review aimed to compare the physical-mechanical properties of 3D-printed (additively manufactured (AM)) zirconia compared to conventionally milled (subtractive manufactured: SM) zirconia specimens. MATERIALS AND METHODS A thorough search of Internet databases was conducted up to September 2023. The search retrieved studies that evaluated AM zirconia specimens and restorations regarding the physical-mechanical properties and mechanical behavior of zirconia. The main topic focused on 3Y-TZP. However, records of 4YSZ and 5YSZ were also included to gather more comprehensive evidence on additively manufactured zirconia ceramic. The quality of studies was assessed using the ROB2 tool, Newcastle Ottawa scale, and the Modified Consort Statement. Of 1736 records, 57 were assessed for eligibility, and 38 records were included in this review, only two clinical trials meet the inclusion criteria and 36 records were laboratory studies. There were no signs of mechanical complications and wear to antagonists with short-term clinical observation. SM thin specimens ≤1.5 mm showed statistically significant higher flexural strength than AM zirconia (p ≤ 0.01), while thicker specimens showed comparable outcomes (p > 0.5). The fracture resistance of dental restorations was dependent on the aging protocol, restoration type, and thickness. The bond strength of veneering ceramic to zirconia core was comparable. CONCLUSIONS The results pooled from two short-term clinical trials showed no signs of mechanical or biological complications of additively manufactured 3Y-TZP zirconia crowns. The flexural strength might depend on the specimens' thickness, but it showed promising results to be used in clinical applications, taking into account the printing technique and orientation, material composition (yttria content), solid loading, and sintering parameters. 3D-printed restorations fracture resistance improved when adhered to human teeth. The veneering ceramic bond was comparable to milled zirconia specimens. Long-term RCTs are recommended to confirm the mechanical behavior of 3D-printed restorations.
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Affiliation(s)
- Mohammed Ahmed Alghauli
- Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany; Department of Prosthodontics, Faculty of Dentistry, Ibb University, Ibb, Yemen.
| | - Ahmed Yaseen Alqutaibi
- Department of Prosthodontics, Faculty of Dentistry, Ibb University, Ibb, Yemen; Department of Substitutive Dental Science, College of Dentistry, Taibah University, Al-Madinah, Saudi Arabia
| | - Sebastian Wille
- Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany
| | - Matthias Kern
- Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany
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Alghauli M, Alqutaibi AY, Wille S, Kern M. 3D-printed versus conventionally milled zirconia for dental clinical applications: Trueness, precision, accuracy, biological and esthetic aspects. J Dent 2024; 144:104925. [PMID: 38471580 DOI: 10.1016/j.jdent.2024.104925] [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: 11/14/2023] [Revised: 02/11/2024] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
OBJECTIVES This systematic review aimed to compare the clinical outcome, internal gap, trueness, precision, and biocompatibility of 3D-printed (AM) compared to milled (SM) zirconia restorations. DATA SOURCE A thorough search of Internet databases was conducted up to September 2023. The search retrieved studies compared AM zirconia to SM zirconia restorations regarding clinical outcome, fit, trueness, precision, and biocompatibility. STUDY SELECTION Of 1736 records, only 59 were screened for eligibility, and 22 records were included in this review. The quality of studies was assessed using the revised Cochrane risk-of-bias tool (ROB2), and the Modified Consort Statement. One clinical study exhibited a low risk of bias. All laboratory studies revealed some bias concerns. Short-term observation showed 100 % survival with no signs of periodontal complications. 3D-printed zirconia crowns showed statistically significant lower ΔE and a better match to adjacent teeth (p ≤ 0.5). The fit, trueness, and precision vary with the printing technique and the tooth surface. CONCLUSIONS 3D-printed zirconia crowns provide better aesthetic color and contour match to adjacent natural teeth than milled crowns. Both 3D printing and milling result in crowns within the clinically acceptable internal and marginal fit. Except for nanoparticle jetting, the marginal gap of SM crowns was smaller than AM crowns, however, both were clinically acceptable. Laminate veneers might be more accurately produced by 3D printing. 3D-printed axial surface trueness was better than milled axial surfaces. Long-term RCTs are recommended to confirm the clinical applicability of 3D-printed restorations. CLINICAL SIGNIFICANCE Internal fit and gap, precision, and trueness are fundamental requirements for successful dental restorations. Both techniques produce restorations with clinically acceptable marginal and internal fit. Axial surfaces and narrow or constricted areas favored 3D-printed than conventionally milled zirconia.
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Affiliation(s)
- Mohammed Alghauli
- Prosthodontics Department, College of Dentistry, Ibb University, Yemen; Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany.
| | - Ahmed Yaseen Alqutaibi
- Prosthodontics Department, College of Dentistry, Ibb University, Yemen; Prosthodontics Department, College of Dentistry, Taibah University, Al-Madinah, Saudi Arabia
| | - Sebastian Wille
- Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany
| | - Matthias Kern
- Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany
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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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Rues S, Herpel C, Ilani A, Schmitt C, Rammelsberg P, Schwindling FS. Effect of firing time and wall thickness on the biaxial flexural strength of 3D-printed zirconia. Dent Mater 2024; 40:484-492. [PMID: 38155019 DOI: 10.1016/j.dental.2023.12.018] [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: 08/29/2023] [Revised: 12/13/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023]
Abstract
OBJECTIVES To evaluate the effect of accelerated firing on 3D-printed zirconia. METHODS To check if formulae provided by ISO 6872 can be extended to thin samples, finite element analyses were carried out in advance of fabricating 3-mol% yttria-stabilized tetragonal zirconia polycrystal discs by milling and by 3D-printing. Four groups (n = 38 each) of 3D-printed specimens were produced with two nominal thicknesses (0.6 mm and 1.2 mm) and two firing strategies (long: 51 h, accelerated: 14.5 h). In the milled group (thickness 1.2 mm, n = 30), a standard firing program (9.8 h) was selected. Biaxial flexural strength tests were applied and mean strength, characteristic strength, and Weibull modulus were calculated for each group. Differences were analyzed using Welch ANOVA and Dunnett-T3 post-hoc tests. RESULTS Maximum tensile stresses occurring during biaxial strength testing can be calculated according to ISO 6872 for thin samples with b > 0.3 mm. Variability of measured strengths values was smaller for milled zirconia compared with 3D-printed zirconia. The 1.2-mm-thick 3D-printed samples had significantly decreased strength after accelerated firing than after long firing. However, for the 0.6-mm-thick samples, comparable mean biaxial strength values of about 1000 MPa were measured for both firing protocols. SIGNIFICANCE At the moment, long fabrication time for zirconia restorations is a major drawback of 3D-printing when compared with milling technology. This investigation showed that the strength of 0.6-mm-thick zirconia discs fabricated by 3D-printing was not impaired by accelerated firing. Thus, overnight firing of thin-walled 3D-printed zirconia restorations could be possible.
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Affiliation(s)
- Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany.
| | - Christopher Herpel
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Ali Ilani
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Clemens Schmitt
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany; Department of Prosthetic Dentistry, Medical University Innsbruck, Innsbruck, Austria
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Franz Sebastian Schwindling
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany; Department of Prosthetic Dentistry, Medical University Innsbruck, Innsbruck, Austria
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Kyung KY, Park JM, Heo SJ, Koak JY, Kim SK, Ahn JS, Yi Y. Comparative analysis of flexural strength of 3D printed and milled 4Y-TZP and 3Y-TZP zirconia. J Prosthet Dent 2024; 131:529.e1-529.e9. [PMID: 38212154 DOI: 10.1016/j.prosdent.2023.12.020] [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: 07/24/2023] [Revised: 12/20/2023] [Accepted: 12/20/2023] [Indexed: 01/13/2024]
Abstract
STATEMENT OF PROBLEM The mechanical properties of 3 dimensionally (3D) printed zirconia have been reported to be comparable with those of milled zirconia, except for the flexural strength. However, most previous studies tested 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP), making it necessary to study 3D printed zirconia with 4 mol% yttria content (4Y-TZP). PURPOSE The purpose of this in vitro study was to compare the flexural strength of 3D printed 4Y-TZP with 3Y-TZP materials and milled 4Y-TZP. MATERIAL AND METHODS A total of 80 disk specimens (Ø15×1.5 mm) were fabricated and divided into 4 groups (n=20) using the fabrication method and yttria content: milled 3Y-TZP (Katana HT; Kuraray Noritake), 3D printed 3Y-TZP (TZ-3Y-E; Tosoh), milled 4Y-TZP (Katana STML; Kuraray Noritake), and 3D printed 4Y-TZP (3DMAT; Genoss). The biaxial flexural strength was determined with a piston-on-3-ball test (n=15). The flexural strength of each specimen was measured, and the Weibull modulus (m) and characteristic strength (σ0) were estimated from the fracture load distribution. Two intact and fractured specimens were examined with scanning electron microscopy (SEM). The crystalline phase of the specimens in each group was identified through X-ray diffraction (XRD) analysis (n=5). A 1-way ANOVA was used to compare the flexural strength among different groups. Subsequently, pairwise comparisons were conducted with the Tukey post hoc method (α=.05). RESULTS The flexural strength of 3D printed 4Y-TZP was significantly higher than that of milled 4Y-TZP (P<.001). In contrast, the flexural strength of 3D printed 3Y-TZP was significantly lower than that of milled 3Y-TZP (P<.001). X-ray diffraction (XRD) analysis revealed that the tetragonal phase was the dominant phase in all groups, with the identification of some cubic phase peaks. CONCLUSIONS Three dimensionally printed 4Y-TZP showed significantly higher flexural strength than milled 4Y-TZP and exhibited a clinically acceptable flexural strength exceeding 800 MPa.
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Affiliation(s)
- Kyu-Young Kyung
- PhD Candidate, Department of Prosthodontics & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Republic of Korea
| | - Ji-Man Park
- Associate Professor, Department of Prosthodontics & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
| | - Seong-Joo Heo
- Professor, Department of Prosthodontics & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Jai-Young Koak
- Professor, Department of Prosthodontics & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Seong-Kyun Kim
- Professor, Department of Prosthodontics & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Jin-Soo Ahn
- Professor, Department of Dental Biomaterials Science & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Yuseung Yi
- Assistant Professor, Department of Prosthodontics & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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Zenthöfer A, Ilani A, Schmitt C, Rammelsberg P, Hetzler S, Rues S. Biaxial flexural strength of 3D-printed 3Y-TZP zirconia using a novel ceramic printer. Clin Oral Investig 2024; 28:145. [PMID: 38351386 PMCID: PMC10864574 DOI: 10.1007/s00784-024-05533-5] [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: 11/15/2023] [Accepted: 01/29/2024] [Indexed: 02/16/2024]
Abstract
OBJECTIVES To compare the strength and reliability of 3D-printed 3Y-TZP zirconia manufactured with various printing orientations and staining. MATERIALS AND METHODS A total of one-hundred cylindrical zirconia specimens were designed and fabricated using 3D printing and processed according to ISO 6872 standards. Of these specimens, 80 were 3D printed using the new ZIPRO-D (ZD) 3D ceramic printer. In this ZD group, 60 specimens were printed in a vertical orientation and were either stained after debinding (ZD1, x-orientation, n = 20) or not stained (ZD2, x-orientation, n = 20; ZD3, y-orientation, n = 20) and the remaining 20 specimens out of n = 80 were printed in a horizontal orientation (ZD4). Further 20 specimens out of the entire sample N = 100 were printed vertically with the CeraFab7500 3D ceramic printer (LC). All completed specimens were loaded until fracture using a universal testing machine. Biaxial flexural strengths and Weibull parameters were computed for the ZD groups and for the LC group. Group and sub-group effects were evaluated using Welch ANOVA (alpha = 0.05). RESULTS The mean (standard deviation, SD) biaxial flexural strengths of vertically oriented ZD samples with (ZD1) and without (ZD2/ZD3) staining were 811 (197) and 850 (152) MPa, respectively (p > 0.05). The ZD4 (horizontally printed), 1107 (144) MPa, and LC (1238 (327)) MPa samples had higher mean (SD) flexural strengths than the ZD1-3 specimens. No difference was observed between the ZD4 and LC group (p > 0.05). Weibull moduli were between m = 4.6 (ZD1) and 9.1 (ZD4) in the ZD group and m = 3.5 in the LC group. CONCLUSIONS All tested 3D-printed zirconia specimens exceeded the flexural strengths required for class 5 restorations according to ISO 6872 standards. While the flexural strengths of zirconia printed using the novel ZD device in the vertical orientation are lower than those of zirconia printed using the LC printer, the ZD printer shows at least comparable reliability. CLINICAL RELEVANCE 3D-printing of zirconia is a new technology in dental application. Based on the presented strengths values, clinical application of 3D-printed zirconia for fixed dental protheses can be recommended.
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Affiliation(s)
- Andreas Zenthöfer
- Department of Prosthodontics, University Clinic Heidelberg, University of Heidelberg, 69120, Heidelberg, Germany.
| | - Ali Ilani
- Department of Prosthodontics, University Clinic Heidelberg, University of Heidelberg, 69120, Heidelberg, Germany
| | - Clemens Schmitt
- Department of Prosthodontics, University Clinic Heidelberg, University of Heidelberg, 69120, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, University Clinic Heidelberg, University of Heidelberg, 69120, Heidelberg, Germany
| | - Sebastian Hetzler
- Department of Prosthodontics, University Clinic Heidelberg, University of Heidelberg, 69120, Heidelberg, Germany
| | - Stefan Rues
- Department of Prosthodontics, University Clinic Heidelberg, University of Heidelberg, 69120, Heidelberg, Germany
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Lee HB, Noh MJ, Bae EJ, Lee WS, Kim JH. Accuracy of zirconia crown manufactured using stereolithography and digital light processing. J Dent 2024; 141:104834. [PMID: 38217958 DOI: 10.1016/j.jdent.2024.104834] [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: 01/26/2023] [Revised: 12/30/2023] [Accepted: 01/07/2024] [Indexed: 01/15/2024] Open
Abstract
OBJECTIVES The aim of this study is to evaluate the accuracy of zirconia crowns fabricated using stereolithography (SLA) and digital light processing (DLP) and to compare their accuracy with those fabricated using the subtractive manufacturing (SM) method. METHODS A typodont model with a prepared maxillary first molar was scanned, and the anatomical contour crown was designed using dental computer-aided-design (CAD) software. The designed file in standard tessellation language (STL) format was used to fabricate 10 crowns per group. The crowns were manufactured using a dental milling machine (Datron D5; MLC group), SLA (CERAMAKER 900; SLAC group), and DLP (ZIPRO; DLPC group) printers. The fabricated crowns were scanned using a dental laboratory scanner and saved in three parts: the external, intaglio, and marginal surfaces. For accuracy assessment, these parts were superimposed to the reference file. Root mean square (RMS) values were evaluated using three-dimensional analysis software (Geomagic Control X). Statistical significance was evaluated using a nonparametric Kruskal-Wallis test (α = 0.05) and a post-hoc Mann-Whitney U test with Bonferroni correction (α = 0.016). RESULTS Trueness evaluation revealed the lowest RMS value in all areas in the MLC group, followed by that in the DLPC group. The precision evaluation revealed the lowest RMS value in all areas in the MLC group. Statistically significant differences were observed among the groups in the external, intaglio, and marginal surface (P < 0.05). CONCLUSIONS Although the restorations fabricated using SM revealed higher accuracy, the crowns manufactured using SLA and DLP methods were considered clinically acceptable. CLINICAL SIGNIFICANCE In the production of zirconia crowns, subtractive manufacturing continues to demonstrate significantly higher accuracy compared to additive manufacturing. However, crowns fabricated using the additive manufacturing method also demonstrated high accuracy.
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Affiliation(s)
- Ha-Bin Lee
- Transdisciplinary Major in Learning Health Systems, Department of Healthcare Sciences, Graduate School, Korea University, Hana Sciences Hall B #374, 145, Anam-ro, Seongbuk-gu, Seoul, Korea
| | - Mi-Jun Noh
- Transdisciplinary Major in Learning Health Systems, Department of Healthcare Sciences, Graduate School, Korea University, Hana Sciences Hall B #374, 145, Anam-ro, Seongbuk-gu, Seoul, Korea
| | - Eun-Jeong Bae
- Department Of Dental Technology, Bucheon University, 56, Sosa-ro, Bucheon, Gyeonggi-do, Korea
| | - Wan-Sun Lee
- Department Of Dental Technology, Bucheon University, 56, Sosa-ro, Bucheon, Gyeonggi-do, Korea
| | - Ji-Hwan Kim
- Transdisciplinary Major in Learning Health Systems, Department of Healthcare Sciences, Graduate School, Korea University, Hana Sciences Hall B #374, 145, Anam-ro, Seongbuk-gu, Seoul, Korea.
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Lu Y, Wang L, Dal Piva AMDO, Tribst JPM, Čokić SM, Zhang F, Werner A, Kleverlaan CJ, Feilzer AJ. Effect of printing layer orientation and polishing on the fatigue strength of 3D-printed dental zirconia. Dent Mater 2024; 40:190-197. [PMID: 37977991 DOI: 10.1016/j.dental.2023.11.007] [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: 08/07/2023] [Revised: 10/23/2023] [Accepted: 11/04/2023] [Indexed: 11/19/2023]
Abstract
OBJECTIVE The aim of the study was to evaluate the influence of surface polishing and printing layer orientation on the fatigue behaviour of 3 mol% yttria-stabilized zirconia (3Y-TZP) by stereolithography (SLA) in comparison with subtractive manufacturing. MATERIALS AND METHODS 60 experimental zirconia bar-shaped specimens were 3D-printed (P) via SLA, and 30 specimens were milled (M) from commercial zirconia block (Lava™ Frame, 3 M ESPE AG). All specimens had the same dimensions (1 mm × 1 mm x 12 mm) after sintering. The 3D-printed specimens were randomly divided according to printing orientations: parallel or perpendicular to the tensile surface in the fatigue test. The specimens were subsequently submitted to two surface finishing protocols (n = 15/gr): unpolished or polished. Their phase compositions were analysed by X-ray diffraction. The fatigue behaviour was evaluated by a stepwise approach. RESULTS The milled and both 3D-printed groups showed similar phase compositions for the as-sintered condition. Considerable amounts of rhombohedral phase were detected after polishing. Milled unpolished samples presented significantly higher fatigue strength than 3D-printed unpolished samples. Polishing did not improve the fatigue strength for milled zirconia but was advantageous for the 3D-printed specimens. 3D-printed specimens with parallel printing-layer orientation were significantly stronger than specimens with perpendicular layers regardless of surface finishing. CONCLUSION The manufacturing techniques had a significant influence on the fatigue strength of 3Y-TZP, but not on the phase compositions of the surface. The polishing protocol showed different effects on 3Y-TZP fatigue strength and induced phase transition of the 3Y-TZP from Tetragonal to Rhombohedral. The best fatigue strength was achieved through milling using an unpolished surface and SLA-printed layers that were parallel to the tensile surface, followed by polishing.
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Affiliation(s)
- Yuqing Lu
- Department of Dental Materials Science, Academic Center for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, the Netherlands
| | - Li Wang
- Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology, School of Mechanical Engineering, Jiangnan University, Wuxi 214122, Jiangsu, China; Institute of Advanced Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Amanda Maria de Oliveira Dal Piva
- Department of Dental Materials Science, Academic Center for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, the Netherlands
| | - João Paulo Mendes Tribst
- Department of Reconstructive Oral Care, Academic Center for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, the Netherlands.
| | - Stevan M Čokić
- KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven (UZ Leuven), Dentistry, Leuven, Belgium
| | - Fei Zhang
- KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven (UZ Leuven), Dentistry, Leuven, Belgium; KU Leuven, Department of Materials Engineering, Kasteelpark Arenberg 44, B-3001 Leuven, Belgium
| | - Arie Werner
- Department of Dental Materials Science, Academic Center for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, the Netherlands
| | - Cornelis J Kleverlaan
- Department of Dental Materials Science, Academic Center for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, the Netherlands
| | - Albert J Feilzer
- Department of Dental Materials Science, Academic Center for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, the Netherlands; Department of Reconstructive Oral Care, Academic Center for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, the Netherlands
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Alghazzawi TF, Janowski GM, Eberhardt AW. An experimental study of flexural strength and hardness of zirconia and their relation to crown failure loads. J Prosthet Dent 2024; 131:320-328. [PMID: 35995603 DOI: 10.1016/j.prosdent.2022.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 11/23/2022]
Abstract
STATEMENT OF PROBLEM Dental zirconia is often marketed and selected for restorative use based upon the biaxial flexural strength of prefabricated specimens (disks) without considering other mechanical and physical properties. PURPOSE The purpose of this in vitro study was to test whether 4-point flexural strength, biaxial flexural strength, and/or hardness may correlate with failure loads for crowns made of different zirconia materials. MATERIAL AND METHODS Three brands of zirconia (BruxZir, Cercon, and Katana) were used to fabricate anatomically contoured crowns, rectangular bars, and circular disks. The sample size was n=15 specimens per zirconia brand and specimen shape. The bars were tested for 4-point flexural strength by using the 4-point bending (4PB) test and Vickers hardness (VH), while the disks were tested for biaxial flexural strength by using a piston-on-3 ball (POB) test. Crowns were attached to resin abutments and compressed with a steel spherical indenter through a polyethylene sheet to assess the failure loads by using the "crunch the crown" (CTC) test. One-way ANOVA (α=.05) was used to test for statistically significant differences between groups, and Weibull analysis was used to assess the variability of the measured flexural strengths, failure load, and hardness. RESULTS Statistical differences (P<.001) were found in comparing Cercon, BruxZir, and Katana ([4260 N=4186 N]>3195 N, respectively) with the CTC test and (396 MPa>[281 MPa=275 MPa], respectively) the 4PB test. No statistical differences (P=.084) were found among the zirconia brands (Cercon [384 MPa]=Bruxzir [359 MPa]=Katana [416 MPa]) for the POB test. No significant correlations (P>.05) were found between the 4PB, POB, or VH tests and the corresponding CTC test. The Weibull modulus varied for the different specimen geometries. CONCLUSIONS The piston-on-3 ball, 4-point bending, and Vickers hardness test results were not correlated with the corresponding crunch-the-crown test.
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Affiliation(s)
- Tariq F Alghazzawi
- Associate Professor, Department of Substitutive Dental Sciences, Taibah University, Madina, Saudi Arabia; Fullbright Scholar, Department of Materials Science and Engineering, The University of Alabama at Birmingham, Birmingham, USA.
| | - Gregg M Janowski
- Professor, Department of Materials Science and Engineering, University of Alabama at Birmingham, Birmingham, Ala
| | - Alan W Eberhardt
- Professor and Associate Chair, Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Ala
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Hajjaj MS, Alamoudi RAA, Babeer WA, Rizg WY, Basalah AA, Alzahrani SJ, Yeslam HE. Flexural strength, flexural modulus and microhardness of milled vs. fused deposition modeling printed Zirconia; effect of conventional vs. speed sintering. BMC Oral Health 2024; 24:38. [PMID: 38185744 PMCID: PMC10771678 DOI: 10.1186/s12903-023-03829-8] [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: 10/17/2023] [Accepted: 12/26/2023] [Indexed: 01/09/2024] Open
Abstract
BACKGROUND Various methods can be used for creating zirconia dental restorations, including 3-dimensional (3D) printing and computer-aided design/ computer-aided manufacturing (CAD/CAM) milling. The fused deposition modeling (FDM) printing method for zirconia presents numerous advantages, albeit research on the mechanical properties of these materials and resultant restorations remains scarce. Such developments are undeniably intriguing and warrant further investigation. The objective of the present study was to evaluate the impact of the sintering firing cycle (Conventional vs. Speed sintering) on the flexural strength, flexural modulus, and Vickers Microhardness of milled vs. FDM printed zirconia. METHODS A total of 60 bars (2 × 5 × 27 mm) were fabricated for flexural strength testing, along with 40 discs (12 × 1.5 mm) for Vickers microhardness testing. Half of the specimens underwent conventional sintering, while the other half underwent a speed sintering cycle. The flexural strength and modulus were determined by a three-point bending test in a universal testing machine. The microhardness of the specimens was evaluated using a Vickers microhardness tester. Statistical analysis was performed using a two-way ANOVA test with a post-hoc Tukey test (p < 0.05). RESULTS CAD/CAM milled zirconia had significantly higher flexural strength and modulus than FDM-printed zirconia. The sintering process did not significantly affect the flexural strength or modulus of milled or FDM-printed zirconia. The milled speed sintering group had significantly higher values in the Vickers microhardness test compared to the other groups. CONCLUSIONS The mechanical properties of FDM-printed zirconia specimens were not found to be comparable to those of milled zirconia. Speed sintering cycle may produce milled zirconia restorations with similar flexural strength and modulus to conventional sintering, and even higher Vickers Microhardness values.
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Affiliation(s)
- Maher S Hajjaj
- Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia.
- Advanced Technology Dental Research Laboratory, King Abdulaziz University, P.O. Box 80209, Jeddah, 21589, Saudi Arabia.
| | - Rana A A Alamoudi
- Prosthodontic Master Student, Department of Oral and Maxillofacial Rehabilitation, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Walaa A Babeer
- Department of Oral and Maxillofacial Rehabilitation, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Waleed Y Rizg
- Department of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
- Center of Innovation in Personalized Medicine (CIPM), 3D Bioprinting Unit, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Ahmad A Basalah
- Mechanical Engineering Department, College of Engineering and Architecture, Umm Al Qura University, Makkah, Saudi Arabia
| | - Saeed J Alzahrani
- Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hanin E Yeslam
- Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
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Frąckiewicz W, Szymlet P, Jedliński M, Światłowska-Bajzert M, Sobolewska E. Mechanical characteristics of zirconia produced additively by 3D printing in dentistry - A systematic review with meta-analysis of novel reports. Dent Mater 2024; 40:124-138. [PMID: 37940500 DOI: 10.1016/j.dental.2023.10.020] [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: 05/17/2023] [Accepted: 10/20/2023] [Indexed: 11/10/2023]
Abstract
OBJECTIVES This study was aimed at comparing the mechanical parameters of ceramics made using the addition and subtraction technique. METHODS A search was performed on four search engines on 5th April 2023. Quality assessment was performed using study type-specific scales. Where possible, a meta-analysis was performed. SOURCES Data were extracted from four search engines: PubMed, PubMed Central, Embase, Web of Science, Scopus. STUDY SELECTION The search strategy identified 686 potential articles. 19 papers were subject to qualitative analysis, and data from 11 papers were meta-analysed. The included studies were of high or medium quality. All included papers were in-vitro studies. No clinical trials were found in the literature. SIGNIFICANCE Ceramics made in the additive technology in terms of mechanical parameters can compete with ceramics made in the milling technology. There are no clinical studies yet that would indicate the use of this type of material for permanent restorations in patients. Studies presented in the literature vary greatly in terms of study design and reporting of results. The research did not receive external funding.
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Affiliation(s)
- Wojciech Frąckiewicz
- Department of Dental Prosthetics, Faculty of Medicine and Dentistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland.
| | - Paweł Szymlet
- Department of Dental Prosthetics, Faculty of Medicine and Dentistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
| | - Maciej Jedliński
- Department of Interdisciplinary Dentistry, Faculty of Medicine and Dentistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
| | - Małgorzata Światłowska-Bajzert
- Department of Dental Prosthetics, Faculty of Medicine and Dentistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
| | - Ewa Sobolewska
- Department of Dental Prosthetics, Faculty of Medicine and Dentistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
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12
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Unnadkat A, Kirby L, Kulanthaivel S, Rysavy O, Tsujimoto A, Song X, Teixeira EC. The Effect of Sintering on Zirconia Manufactured via Suspension-Enclosing Projection Stereolithography for Dental Applications: An In Vitro Study. MATERIALS (BASEL, SWITZERLAND) 2023; 17:14. [PMID: 38203868 PMCID: PMC10779720 DOI: 10.3390/ma17010014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 01/12/2024]
Abstract
BACKGROUND Zirconia is a widely used material in the dental industry due to its excellent mechanical and aesthetic properties. Recently, a new 3D printing process called suspension-enclosing projection stereolithography (SEPS) was introduced to fabricate zirconia dental restorations. However, the effect of the sintering time and temperature on the properties of zirconia produced via SEPS has not been fully investigated. METHODS Zirconia slurries were prepared with varying percentages of zirconia powders and 3D printing resins, and 5Y-TZP (5 mol% yttria-stabilized zirconia) (n = 40) and 3Y-TZP (3 mol% yttria-stabilized zirconia) (n = 40) bar specimens were fabricated via SEPS manufacturing. The specimens were sintered at different temperatures and dwell times, and their flexural strength, density, and phase composition were measured. The viscosity of the slurries was also measured. Statistical analysis was performed using Welch's ANOVA and Kruskal-Wallis tests to evaluate the impact of the sintering conditions. RESULTS Significant differences in flexural strength (p < 0.01) were observed between the 5Y-TZP samples, with those sintered at 1530 °C for 120 min showing an average strength of 268.34 ± 44.66 MPa, compared to 174.16 ± 42.29 MPa for those sintered at 1450 °C for 120 min. In terms of density, significant differences (p < 0.01) were noted for the 3Y-TZP specimens, with an average density of 6.66 ± 0.49 g/cm3 for samples sintered at 1530 °C for 120 min, versus 5.75 ± 0.55 g/cm3 for those sintered at 1530 °C for 10 min. X-ray diffraction confirmed the presence of a predominantly tetragonal phase in both materials. CONCLUSIONS Zirconia printed via SEPS manufacturing can be sintered at a higher temperature with shorter dwell times, thereby producing high density samples. Different sintering conditions can be used to fully sinter 3D-printed zirconia for potential dental applications.
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Affiliation(s)
- Amit Unnadkat
- Department of General Dentistry, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA;
| | - Levi Kirby
- Department of Industrial and Systems Engineering, The University of Iowa College of Engineering, Iowa City, IA 52242, USA
| | - Senthilguru Kulanthaivel
- Department of Operative Dentistry, The University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA 52242, USA; (S.K.); (A.T.)
| | - Oscar Rysavy
- Division of Biostatistics and Computational Biology, The University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA 52242, USA
- Department of Biostatistics, The University of Iowa College of Public Health, Iowa City, IA 52242, USA
| | - Akimasa Tsujimoto
- Department of Operative Dentistry, The University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA 52242, USA; (S.K.); (A.T.)
- Department of Operative Dentistry, Aichi Gakuin University School of Dentistry, Chikusa-ku, Nagoya 464-8651, Aichi, Japan
- Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE 68102, USA
| | - Xuan Song
- Department of Industrial and Systems Engineering, The University of Iowa College of Engineering, Iowa City, IA 52242, USA
| | - Erica C. Teixeira
- Department of Operative Dentistry, The University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA 52242, USA; (S.K.); (A.T.)
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13
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Miura S, Shinya A, Ishida Y, Fujita T, Vallittu P, Lassila L, Fujisawa M. The effect of low-temperature degradation and building directions on the mechanical properties of additive-manufactured zirconia. Dent Mater J 2023; 42:800-805. [PMID: 37793824 DOI: 10.4012/dmj.2023-089] [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] [Indexed: 10/06/2023]
Abstract
This study aimed to investigate the effect of low-temperature degradation (LTD) on the mechanical properties of additive-manufactured zirconia. In addition, the mechanical properties of additive-manufactured were compared with those before aging under similar experimental conditions. This study prepared stereolithography apparatus fabricated zirconia specimens with flexural strength, modulus of elasticity, Vickers hardness, and fracture toughness. The specimen position data were set as parallel (0°), diagonal (45°), and perpendicular (90°) to the direction of the building. The LTD condition was 5 h under 134ºC and 0.2 MPa in an autoclave. It was found that the 0° direction differed significantly from all other conditions before and after aging, and the highest flexural strength was obtained when the additive specimen was manufactured perpendicular to the building direction. However, the results indicate that there is a negligible effect of aging on the mechanical properties of additive-manufactured zirconia.
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Affiliation(s)
- Shoko Miura
- Division of Fixed Prosthodontics, Department of Restorative and Biomaterials Sciences, Meikai University School of Dentistry
- Department of Biomaterials Science and Turku Clinical Biomaterials Center-TCBC, Institute of Dentistry, University of Turku
| | - Akikazu Shinya
- Department of Dental Materials Sciences, School of Life Dentistry at Tokyo, The Nippon Dental University
- Department of Prosthetic Dentistry and Biomaterials Science, Institute of Dentistry, University of Turku
| | - Yoshiki Ishida
- Department of Dental Materials Sciences, School of Life Dentistry at Tokyo, The Nippon Dental University
| | - Takafumi Fujita
- Division of Fixed Prosthodontics, Department of Restorative and Biomaterials Sciences, Meikai University School of Dentistry
| | - Pekka Vallittu
- Department of Biomaterials Science and Turku Clinical Biomaterials Center-TCBC, Institute of Dentistry, University of Turku
- Department of Prosthetic Dentistry and Biomaterials Science, Institute of Dentistry, University of Turku
- Welfare District of County of Southwest Finland
| | - Lippo Lassila
- Department of Biomaterials Science and Turku Clinical Biomaterials Center-TCBC, Institute of Dentistry, University of Turku
| | - Masanori Fujisawa
- Division of Fixed Prosthodontics, Department of Restorative and Biomaterials Sciences, Meikai University School of Dentistry
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Beyabanaki E, Ashtiani RE, Moradi M, Namdari M, Mostafavi D, Zandinejad A. Biaxial flexural strength and Weibull characteristics of a resin ceramic material after thermal-cycling. J Prosthodont 2023; 32:721-727. [PMID: 36401608 DOI: 10.1111/jopr.13622] [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: 08/28/2022] [Accepted: 11/15/2022] [Indexed: 10/13/2023] Open
Abstract
PURPOSE The purpose of this in vitro study was to compare the flexural strength and Weibull characteristics of 3 different resin-ceramic materials with a zirconia-reinforced lithium silicate material after thermal-cycling. MATERIAL AND METHODS Four different computer-aided design and computer-aided manufacturing restorative materials (Vita Enamic, Lava Ultimate, Crystal Ultra, and Vita Suprinity) were tested. A total of 40 Ø12×1.2-mm disks were prepared and divided into 4 groups (n = 10). Their flexural strength was evaluated after 5000 thermal-cycles with a 4-point biaxial flexure test using a universal testing machine. The Weibull modulus and probability of failure were also determined from the biaxial flexural strength data. Data were analyzed with one-way ANOVA and the Tukey pairwise comparison test (α = 0.05). RESULTS Significant differences were found among the materials in terms of biaxial flexural strength (p < 0.05). Vita Suprinity had the highest mean ±standard deviation flexural strength (289.1 ± 15.1 MPa), and Vita Enamic had the lowest (100.0 ± 3.2 MPa). The highest Weibull modulus was calculated for Crystal Ultra, followed by Vita Enamic, Lava Ultimate, and Vita Suprinity. CONCLUSION Vita Suprinity had the highest flexural strength when compared with the other materials tested. Crystal Ultra had the highest flexural strength among the resin-ceramic materials. The highest Weibull modulus was calculated for Crystal Ultra and the lowest for Vita Suprinity.
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Affiliation(s)
- Elaheh Beyabanaki
- Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Reza Eftekhar Ashtiani
- Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Mahshid Namdari
- Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Amirali Zandinejad
- Comprehensive Dentistry Department, College of Dentistry, Texas A&M University, Dallas, Texas
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15
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Giugliano TS, Zhang Y, Janal MN, Lim CH, Smith RM, Choi M. In vitro comparison of physical characteristics of milled versus printed zirconia discs. J Prosthodont 2023:10.1111/jopr.13778. [PMID: 37776103 PMCID: PMC10980599 DOI: 10.1111/jopr.13778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 10/01/2023] Open
Abstract
PURPOSE The purpose of this study was to compare the dimensional accuracy, translucency, and biaxial flexural strength of milled zirconia (MZ) versus 3D-printed zirconia (PZ) discs. MATERIALS & METHODS A circular disc measuring 14.0 mm in diameter and 1.20 mm in thickness was designed using computer-aided design (CAD) software. The resulting standard tessellation language (STL) file was used both as a control and to fabricate 36 zirconia (3Y-TZP) disc specimens (n = 36): 18 were milled (group MZ) and 18 were 3D-printed (group PZ). The diameter and thickness of each disc were measured using a digital caliper. Translucency was evaluated using a calibrated dental colorimeter. The flexural strength was determined using the piston-on-three-ball biaxial flexure test. All measurements were done by one blinded examiner. The statistical significance level was set to α = 0.05. RESULTS The MZ discs had significantly more accurate dimensions than the PZ discs in both diameter and thickness when compared to the control CAD software-designed disc. The MZ discs exhibited significantly higher translucency (translucency parameter (TP) = 16.95 ±0.36 vs. 9.24 ±1.98) and biaxial flexural strength (996.16 ±137.37 MPa vs. 845.75 ±266.16 MPa) than the PZ discs. Finally, MZ possessed a significantly higher Weibull modulus relative to PZ. CONCLUSIONS The results showed that the milled specimens achieved better dimensional accuracy and were more translucent, stronger, and less prone to failure than printed specimens.
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Affiliation(s)
- Thomas S. Giugliano
- Department of Prosthodontics, New York University College of Dentistry, New York, NY
| | - Yu Zhang
- Laboratories for Microstructure Physics & Mechanics of Materials, Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA
| | - Malvin N. Janal
- Department of Epidemiology & Health Promotion, New York University College of Dentistry, New York, NY
| | - Chek Hai Lim
- Laboratories for Microstructure Physics & Mechanics of Materials, Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ruby M. Smith
- Post-Graduate Student, Department of Prosthodontics, New York University College of Dentistry, New York, NY
| | - Mijin Choi
- Department of Prosthodontics, New York University College of Dentistry, New York, NY
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16
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Zhu H, Zhou Y, Jiang J, Wang Y, He F. Accuracy and margin quality of advanced 3D-printed monolithic zirconia crowns. J Prosthet Dent 2023:S0022-3913(23)00444-4. [PMID: 37591717 DOI: 10.1016/j.prosdent.2023.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 08/19/2023]
Abstract
STATEMENT OF PROBLEM Nanoparticle jetting (NPJ) is a novel ceramic 3D-printing technology with high printing accuracy. However, studies reporting the accuracy of zirconia crowns manufactured by NPJ and comparing them with conventional zirconia crowns are lacking. PURPOSE The purpose of this in vitro study was to evaluate and compare the trueness, crown fit, and margin quality of monolithic zirconia crowns manufactured by NPJ with those milled by a computer numerical control system. MATERIAL AND METHODS A gypsum left mandibular first molar was prepared and scanned with an intraoral scanner (TRIOS 4). Three types of monolithic crowns were manufactured through 3D printing and subtractive manufacturing (SM): NPJ (3D printing), VITA (milling), UPCERA (milling). The crowns were scanned, and the dimensional deviation (trueness) was evaluated and compared by using a software program. The triple scan method was used to measure crown fit and uniform index through precise alignment in the software program, and margin quality was also observed with an optical microscope. The data were analyzed with 1-way analysis of variance and the Tukey post hoc test (α=.05). RESULTS The NPJ group reported better trueness of all crown and axial surfaces compared with the other SM group (P<.001), but marginal trueness (P=.601), intaglio surface (P=.596), and occlusal surface (P=.641) were statistically similar compared with the Vita milled group. All 3 groups reported clinically acceptable crown fit and uniformity with statistically similar values (P>.05). The NPJ group had more crowns judged to have flawless margin quality compared with the milled groups. CONCLUSIONS All 3 manufacturing methods can fabricate zirconia crowns with a clinically acceptable crown fit. The NPJ system could be used to manufacture monolithic zirconia crowns with better margin quality and proximal surface trueness than milled crowns.
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Affiliation(s)
- Han Zhu
- Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Yi Zhou
- Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Jimin Jiang
- Department of Prosthodontics, Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Yujie Wang
- Department of Periodontics, Department of Prosthodontics, Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Fuming He
- Department of Prosthodontics and Implantology, Department of Prosthodontics, Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China.
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17
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Miura S, Shinya A, Ishida Y, Fujisawa M. Mechanical and surface properties of additive manufactured zirconia under the different building directions. J Prosthodont Res 2023; 67:410-417. [PMID: 36403961 DOI: 10.2186/jpr.jpr_d_22_00166] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
Abstract
PURPOSE This study investigates the mechanical and surface properties of zirconia manufactured using additive manufacturing (AM) technology and the effect of the building direction on the mechanical and surface properties. METHODS Specimens were prepared using ZrO2 paste (3DMix ZrO2; 3DCeram) and a three-dimensional printing system (CeraMaker 900; 3DCeram) based on the principles of stereolithography (SLA). The mechanical properties (flexural strength, Vickers hardness, fracture toughness, elastic modulus, and Poisson's ratio) and surface properties (chemical composition and surface observation) were evaluated for three building directions (parallel, diagonal, and perpendicular) to investigate the relationship between the building directions and the anisotropy of the mechanical and surface properties of SLA-manufactured zirconia. Statistical analysis was performed using a one-way analysis of variance and Tukey's honestly significant difference test. RESULTS The highest flexural strength was obtained for a perpendicular building direction. The flexural strength was significantly higher in the perpendicular direction than in the parallel and diagonal directions; it was also significantly higher in the diagonal direction than in the parallel direction (P<0.05). The Vickers hardness, fracture toughness, elastic modulus, Poisson's ratio, and chemical composition did not differ significantly. Microstructural observations revealed that the layers, large crystals, and pores were more prominent in the parallel direction. CONCLUSIONS The flexural strength and surface structure of the tested SLA-manufactured zirconia were influenced by the building direction; however, other mechanical properties remained unaffected. The layer boundaries affected the anisotropic behavior of the builds to a certain extent, owing to the layer-by-layer production method.
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Affiliation(s)
- Shoko Miura
- Division of Fixed Prosthodontics, Department of Restorative & Biomaterials Sciences, Meikai University School of Dentistry, Japan
| | - Akikazu Shinya
- Department of Dental Materials Sciences, School of Life Dentistry at Tokyo, The Nippon Dental University, Japan
- Department of Prosthetic Dentistry and Biomaterials Science, Institute of Dentistry, University of Turku, Finland
| | - Yoshiki Ishida
- Department of Dental Materials Sciences, School of Life Dentistry at Tokyo, The Nippon Dental University, Japan
| | - Masanori Fujisawa
- Division of Fixed Prosthodontics, Department of Restorative & Biomaterials Sciences, Meikai University School of Dentistry, Japan
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18
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Lu Y, Wang L, Dal Piva AMO, Tribst JPM, Nedeljkovic I, Kleverlaan CJ, Feilzer AJ. Influence of surface finishing and printing layer orientation on surface roughness and flexural strength of stereolithography-manufactured dental zirconia. J Mech Behav Biomed Mater 2023; 143:105944. [PMID: 37269603 DOI: 10.1016/j.jmbbm.2023.105944] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/27/2023] [Accepted: 05/28/2023] [Indexed: 06/05/2023]
Abstract
OBJECTIVE To evaluate the effect of surface finishing and printing layer orientation on the surface roughness and flexural strength of three-dimensionally (3D) printed 3 mol% yttria-stabilized zirconia manufactured by stereolithography (SLA). METHODS Ninety bar-shaped zirconia specimens (1 mm x 1 mm x 12 mm) were 3D-printed via SLA. After debinding and sintering, they were randomly divided according to the printing layer orientation: parallel (PR) or perpendicular (PD) to the tensile surface for bending test. Each group was submitted to a surface finishing protocol (n=15/group): unpolished (subgroup 0), with polished tensile surface (subgroup 1), and with polished lateral and tensile surfaces (subgroup 3). Roughness of tensile surface was determined using a contact sensor and surface morphology was analyzed under Scanning Electron Microscopy (SEM). Flexural strength, apparent elastic modulus, and Weibull parameters were assessed using a 3-point bending test. Fractured specimens were examined to identify failure origins. Finite element analysis was used to evaluate tensile stress peaks and failure risk. RESULTS PR orientation exhibited higher strength, higher apparent elastic modulus, higher maximum principal stress peaks, and lower failure risk. For both layer orientations, groups with polished lateral and tensile sides (PR3 and PD3) were the strongest. SEM revealed that polishing led to changes in defect type, location, and size. SIGNIFICANCE SLA zirconia shows different mechanical properties according to surface roughness and defects. Orienting the printed layers parallel to the tensile side improves its mechanical performance. Polishing can significantly improve its flexural strength. It is necessary to reduce the final product's surface roughness and large pores for its best performance.
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Affiliation(s)
- Y Lu
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, the Netherlands
| | - L Wang
- Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology, School of Mechanical Engineering, Jiangnan University, Wuxi, 214122, Jiangsu, China; Institute of Advanced Technology, Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - A M O Dal Piva
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, the Netherlands.
| | - J P M Tribst
- Department of Reconstructive Oral Care, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, the Netherlands
| | - I Nedeljkovic
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, the Netherlands
| | - C J Kleverlaan
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, the Netherlands
| | - A J Feilzer
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, the Netherlands; Department of Reconstructive Oral Care, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, the Netherlands
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Teegen IS, Schadte P, Wille S, Adelung R, Siebert L, Kern M. Comparison of properties and cost efficiency of zirconia processed by DIW printing, casting and CAD/CAM-milling. Dent Mater 2023; 39:669-676. [PMID: 37230861 DOI: 10.1016/j.dental.2023.05.001] [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: 10/19/2022] [Revised: 04/27/2023] [Accepted: 05/02/2023] [Indexed: 05/27/2023]
Abstract
OBJECTIVES The aim of this study was to evaluate the mechanical properties and cost efficiency of direct ink writing (DIW) printing of two different zirconia inks compared to casting and subtractive manufacturing. METHODS Zirconia disks were manufactured by DIW printing and the casting process and divided into six subgroups (n = 20) according to sintering temperatures (1350 °C, 1450 °C and 1550 °C) and two different ink compositions (Ink 1, Ink 2). A CAD/CAM-milled high strength zirconia (3Y-TZP) was added as reference group. The biaxial flexural strength (BFS) was measured using the piston-on-three-balls test. X-ray-diffraction (XRD) was used for microstructural analysis. The cost efficiency was compared for DIW printing and subtractive manufacturing by calculation of the manufacturing costs of one dental crown. RESULTS Using XRD, monoclinic and tetragonal phases were detected for Ink 1, for all other groups no monoclinic phase was detected. The CAD/CAM-milled ceramic showed a significantly higher BFS than all other groups. The BFS of Ink 2 was significantly higher than the BFS of Ink 1. At a sintering temperature of 1550 °C the mean BFS of the printed Ink 2 was 822 ± 174 MPa. The BFS of the cast materials did not show a significantly higher BFS than the corresponding printed group for any tested parameter-set. The manufacturing costs of DIW printed crowns are lower than the manufacturing costs of CAD/CAM-milled crowns. CONCLUSION DIW has a high potential to replace subtractive processes for dental applications, as it shows promising mechanical properties for appropriate ink compositions and facilitates a highly cost effective production.
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Affiliation(s)
- Isabell-Sophie Teegen
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Kiel University, Arnold-Heller-Straße 16, 24105 Kiel, Germany.
| | - Philipp Schadte
- Department of Material Science, Faculty of Engineering, Kiel University, Kaiserstr. 2, 24143 Kiel, Germany.
| | - Sebastian Wille
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Kiel University, Arnold-Heller-Straße 16, 24105 Kiel, Germany.
| | - Rainer Adelung
- Department of Material Science, Faculty of Engineering, Kiel University, Kaiserstr. 2, 24143 Kiel, Germany.
| | - Leonard Siebert
- Department of Material Science, Faculty of Engineering, Kiel University, Kaiserstr. 2, 24143 Kiel, Germany.
| | - Matthias Kern
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Kiel University, Arnold-Heller-Straße 16, 24105 Kiel, Germany.
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Yoo LG, Pang NS, Kim SH, Jung BY. Mechanical properties of additively manufactured zirconia with alumina air abrasion surface treatment. Sci Rep 2023; 13:9153. [PMID: 37280320 DOI: 10.1038/s41598-023-36181-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/29/2023] [Indexed: 06/08/2023] Open
Abstract
This study aimed to evaluate the mechanical properties of zirconia fabricated using additive manufacturing technology and compare them to those of zirconia fabricated using subtractive manufacturing technology. Sixty disc-shaped specimens were fabricated for the additive (n = 30) and subtractive manufacturing groups (n = 30), and each group was divided into two subgroups according to their air-abrasion surface treatment: control (n = 15) and air-abrasion groups (n = 15). Mechanical properties including the flexural strength (FS), Vickers hardness, and surface roughness were determined, and the values were analyzed by one-way ANOVA and Tukey's post hoc test (α = 0.05). X-ray diffraction and scanning electron microscopy were used for phase analysis and surface topography evaluation, respectively. The SMA group exhibited the highest FS (1144.97 ± 168.1 MPa), followed by the SMC (944.58 ± 141.38 MPa), AMA (905.02 ± 111.38 MPa), and AMC groups (763.55 ± 68.69 MPa). The Weibull distribution showed the highest scale value (1213.55 MPa) in the SMA group, with the highest shape value in the AMA group (11.69). A monoclinic peak was not detected in both the AMC and SMC groups, but after air abrasion, the monoclinic phase content ([Formula: see text]) reached 9% in the AMA group, exceeding that in the SMA group (7%). The AM groups exhibited statistically lower FS values than those of the SM groups under the same surface treatment (p < 0.05). Air-abrasion surface treatment increased the monoclinic phase content and FS (p < 0.05) in both the additive and subtractive groups, while it increased the surface roughness (p < 0.05) only in the additive group and did not affect the Vickers hardness in either group. For zirconia manufactured using additive technology, the mechanical properties are comparable to those of zirconia manufactured using subtractive technology.
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Affiliation(s)
- Lee-Gang Yoo
- Department of Advanced General Dentistry, College of Dentistry, Yonsei University, 50 Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, South Korea
| | - Nan-Sim Pang
- Department of Advanced General Dentistry, College of Dentistry, Yonsei University, 50 Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, South Korea
| | - So-Hyun Kim
- Department of Dentistry, Inha University Hospital, Inha University School of Medicine, Incheon, Korea
| | - Bock-Young Jung
- Department of Advanced General Dentistry, College of Dentistry, Yonsei University, 50 Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, South Korea.
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21
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Branco AC, Colaço R, Figueiredo-Pina CG, Serro AP. Recent Advances on 3D-Printed Zirconia-Based Dental Materials: A Review. MATERIALS (BASEL, SWITZERLAND) 2023; 16:1860. [PMID: 36902976 PMCID: PMC10004380 DOI: 10.3390/ma16051860] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Zirconia-based materials are widely used in dentistry due to their biocompatibility and suitable mechanical and tribological behavior. Although commonly processed by subtractive manufacturing (SM), alternative techniques are being explored to reduce material waste, energy consumption and production time. 3D printing has received increasing interest for this purpose. This systematic review intends to gather information on the state of the art of additive manufacturing (AM) of zirconia-based materials for dental applications. As far as the authors know, this is the first time that a comparative analysis of these materials' properties has been performed. It was performed following the PRISMA guidelines and using PubMed, Scopus and Web of Science databases to select studies that met the defined criteria without restrictions on publication year. Stereolithography (SLA) and digital light processing (DLP) were the techniques most focused on in the literature and the ones that led to most promising outcomes. However, other techniques, such as robocasting (RC) and material jetting (MJ), have also led to good results. In all cases, the main concerns are centered on dimensional accuracy, resolution, and insufficient mechanical strength of the pieces. Despite the struggles inherent to the different 3D printing techniques, the commitment to adapt materials, procedures and workflows to these digital technologies is remarkable. Overall, the research on this topic can be seen as a disruptive technological progress with a wide range of application possibilities.
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Affiliation(s)
- Ana Catarina Branco
- Centro de Química Estrutural (CQE), Departamento de Engenharia Química, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
- Centro de Desenvolvimento de Produto e Transferência de Tecnologia, Department of Mechanical Engineering, Escola Superior de Tecnologia de Setúbal, Instituto Politécnico de Setúbal, Estefanilha, 2910-761 Setúbal, Portugal
- Centro de Investigação Interdisciplinar Egas Moniz, Instituto Universitário Egas Moniz, Quinta da Granja, Monte de Caparica, 2829-511 Caparica, Portugal
| | - Rogério Colaço
- Departamento de Engenharia Mecânica, Instituto de Engenharia Mecânica, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Célio Gabriel Figueiredo-Pina
- Centro de Desenvolvimento de Produto e Transferência de Tecnologia, Department of Mechanical Engineering, Escola Superior de Tecnologia de Setúbal, Instituto Politécnico de Setúbal, Estefanilha, 2910-761 Setúbal, Portugal
- Centro de Investigação Interdisciplinar Egas Moniz, Instituto Universitário Egas Moniz, Quinta da Granja, Monte de Caparica, 2829-511 Caparica, Portugal
- Center of Physics and Engineering of Advanced Materials, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Ana Paula Serro
- Centro de Química Estrutural (CQE), Departamento de Engenharia Química, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
- Centro de Investigação Interdisciplinar Egas Moniz, Instituto Universitário Egas Moniz, Quinta da Granja, Monte de Caparica, 2829-511 Caparica, Portugal
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Espino MT, Tuazon BJ, Espera AH, Nocheseda CJC, Manalang RS, Dizon JRC, Advincula RC. Statistical methods for design and testing of 3D-printed polymers. MRS COMMUNICATIONS 2023; 13:193-211. [PMID: 37153534 PMCID: PMC9976681 DOI: 10.1557/s43579-023-00332-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 01/23/2023] [Indexed: 05/09/2023]
Abstract
Different statistical methods are used in various fields to qualify processes and products, especially in emerging technologies like Additive Manufacturing (AM) or 3D printing. Since several statistical methods are being employed to ensure quality production of the 3D-printed parts, an overview of these methods used in 3D printing for different purposes is presented in this paper. The advantages and challenges, to understanding the importance it brings for design and testing optimization of 3D-printed parts are also discussed. The application of different metrology methods is also summarized to guide future researchers in producing dimensionally-accurate and good-quality 3D-printed parts. This review paper shows that the Taguchi Methodology is the commonly-used statistical tool in optimizing mechanical properties of the 3D-printed parts, followed by Weibull Analysis and Factorial Design. In addition, key areas such as Artificial Intelligence (AI), Machine Learning (ML), Finite Element Analysis (FEA), and Simulation require more research for improved 3D-printed part qualities for specific purposes. Future perspectives are also discussed, including other methods that can help further improve the overall quality of the 3D printing process from designing to manufacturing. Graphical abstract
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Affiliation(s)
- Michaela T. Espino
- Department of Industrial Engineering, College of Engineering and Architecture, Bataan Peninsula State University-Main Campus, 2100 City of Balanga, Bataan Philippines
- DR3AM Center, Bataan Peninsula State University-Main Campus, 2100 City of Balanga, Bataan Philippines
| | - Brian J. Tuazon
- Department of Mechanical Engineering, College of Engineering and Architecture, Bataan Peninsula State University-Main Campus, 2100 City of Balanga, Bataan Philippines
- DR3AM Center, Bataan Peninsula State University-Main Campus, 2100 City of Balanga, Bataan Philippines
| | - Alejandro H. Espera
- Electronics Engineering Department, School of Engineering and Architecture, Ateneo de Davao University, 8016 Davao City, Philippines
- Department of Engineering Education, College of Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 USA
- Department of Chemical and Biomolecular Engineering and Institute for Advanced Materials and Manufacturing, University of Tennessee, Knoxville, TN 37996 USA
| | - Carla Joyce C. Nocheseda
- Department of Science and Technology, Advanced Manufacturing Center (AMCen), Metals Industry Research and Development Center, Gen. Santos Ave., Bicutan, 1631 Taguig City, Philippines
| | - Roland S. Manalang
- Department of Electrical Engineering, College of Engineering and Architecture, Bataan Peninsula State University-Main Campus, 2100 City of Balanga, Bataan Philippines
| | - John Ryan C. Dizon
- Department of Industrial Engineering, College of Engineering and Architecture, Bataan Peninsula State University-Main Campus, 2100 City of Balanga, Bataan Philippines
- DR3AM Center, Bataan Peninsula State University-Main Campus, 2100 City of Balanga, Bataan Philippines
| | - Rigoberto C. Advincula
- Center for Nanophase Materials and Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- Department of Chemical and Biomolecular Engineering and Institute for Advanced Materials and Manufacturing, University of Tennessee, Knoxville, TN 37996 USA
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23
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Bonfante EA, Calamita M, Bergamo ETP. Indirect restorative systems-A narrative review. J ESTHET RESTOR DENT 2023; 35:84-104. [PMID: 36688803 DOI: 10.1111/jerd.13016] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/24/2023]
Abstract
OBJECTIVE The background and clinical understanding of the properties of currently available indirect restorative systems and fabrication methods is, along with manufacturer and evidence-based literature, an important starting point to guide the clinical selection of materials for tooth and/or implant supported reconstructions. Therefore, this review explores most indirect restorative systems available in the market, especially all-ceramic, along with aspects of manufacturing process, clinical survival rates, and esthetic outcomes. OVERVIEW Progressive incorporation of new technologies in the dental field and advancements in materials science have enabled the development/improvement of indirect restorative systems and treatment concepts in oral rehabilitation, resulting in reliable and predictable workflows and successful esthetic and functional outcomes. Indirect restorative systems have evolved from metal ceramics and polymers to glass ceramics, polycrystalline ceramics, and resin-matrix ceramics, aiming to improve not only biological and mechanical properties, but especially the optical properties and esthetic quality of the reconstructions, in attempt to mimic natural teeth. CONCLUSIONS Based on several clinical research, materials, and patient-related parameters, a decision tree for the selection of indirect restorative materials was suggested to guide clinicians in the rehabilitation process. CLINICAL SIGNIFICANCE The pace of materials development is faster than that of clinical research aimed to support their use. Since no single material provides an ideal solution to every case, professionals must continuously seek information from well designed, long-term clinical trials in order to incorporate or not new materials and technological advancements.
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Affiliation(s)
- Estevam A Bonfante
- Department of Prosthodontics and Periodontology, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil
| | - Marcelo Calamita
- Department of Restorative Dental Sciences at the University of Florida, Gainesville, Florida, USA
| | - Edmara T P Bergamo
- Department of Prosthodontics and Periodontology, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil
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24
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Revilla-León M, Al-Haj Husain N, Barmak AB, Pérez-López J, Raigrodski AJ, Özcan M. Chemical Composition and Flexural Strength Discrepancies Between Milled and Lithography-Based Additively Manufactured Zirconia. J Prosthodont 2022; 31:778-783. [PMID: 35068002 DOI: 10.1111/jopr.13482] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/13/2022] [Indexed: 01/04/2023] Open
Abstract
PURPOSE To evaluate the chemical composition, flexural strength, and Weibull characteristics of milled and lithography-based additively manufactured (AM) zirconia. MATERIALS AND METHODS A virtual design of a bar (25×4×2 mm) was completed using a software program. The standard tessellation language file was used to manufacture all the specimens: 3Y-TZP zirconia (Priti multidisc ZrO2 monochrome) milled (M group) and 3Y-TZP zirconia (LithaCon 3Y 210) lithography-based AM (CeraFab System S65 Medical) (AM group) bar specimens (n = 20). The chemical composition of the specimens was determined by using energy dispersive X-ray (EDAX) elemental analysis in a scanning electron microscope. Flexural strength was measured in all specimens using 3-point bend test according to ISO/CD 6872.2 with a universal testing machine (Instron Model 8501). Two-parameter Weibull distribution values were calculated. The Shapiro-Wilk test revealed that the data were normally distributed (p < 0.05). Flexural strength values were analyzed using independent Student's t-test (α = 0.05). RESULTS There were no major chemical composition differences observed between M and AM groups. The AM specimens (1518.9 ± 253.9 MPa) exhibited a significantly higher flexural strength mean value compared to the milled (980.5 ± 130.3 MPa) specimens (DF = 13, T-value = -5.97, p < 0.001). The Weibull distribution presented the highest shape for M specimens (11.49) compared to those of AM specimens (6.95). CONCLUSIONS There was no significant difference in the chemical composition of milled and AM zirconia material tested. AM zirconia tested exhibited significantly higher flexural strength compared with the milled zirconia evaluated.
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Affiliation(s)
- Marta Revilla-León
- Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA.,Kois Center, Seattle, WA.,Department of Prosthodontics, School of Dental Medicine, Tufts University, Boston, MA
| | - Nadin Al-Haj Husain
- University of Zurich, Clinic for Reconstructive Dentistry, Division of Dental Biomaterials, Center of Dental Medicine, Zurich, Switzerland.,Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland
| | - Abdul B Barmak
- Eastman Institute of Oral Health, University of Rochester Medical Center, Rochester, NY
| | | | - Ariel J Raigrodski
- Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA.,Private Practice, Lynnwood, WA
| | - Mutlu Özcan
- University of Zurich, Clinic for Reconstructive Dentistry, Division of Dental Biomaterials, Center of Dental Medicine, Zurich, Switzerland
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25
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Abualsaud R, Alalawi H. Fit, Precision, and Trueness of 3D-Printed Zirconia Crowns Compared to Milled Counterparts. Dent J (Basel) 2022; 10:dj10110215. [PMID: 36421402 PMCID: PMC9689223 DOI: 10.3390/dj10110215] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 11/13/2022] Open
Abstract
Precise fit of a crown and accurate reproduction of the digital design are paramount for successful treatment outcomes and preservation of clinician and technician time. The study aimed to compare the internal fit, marginal adaptation, precision, and trueness of 3D-printed zirconia crowns compared to their milled counterpart. A total of 20 monolithic 3 mol% yttria stabilized-zirconia crowns (n = 10) were made using computer-assisted design (CAD) followed by additive (3D-printed) and subtractive (milled) manufacturing. Digital scanning of the master die with and without a fit checker followed by image superimposition, and analysis was performed to evaluate internal and marginal adaptation in four areas (occlusal, axial, marginal, and overall). ISO 12836:2015 standard was followed for precision and trueness evaluation. Statistical analysis was achieved using a t-test at α = 0.05. Internal fit and marginal adaptation revealed no significant difference between the two test groups (p > 0.05). The significant difference in trueness (p < 0.05) was found between the two groups in three areas (occlusal, axial, and internal). The best and worst trueness values were seen with 3D-printed crowns at occlusal (8.77 ± 0.89 µm) and Intaglio (23.90 ± 1.60 µm), respectively. The overall precision was statistically better (p < 0.05) in the 3D-printed crowns (9.59 ± 0.75 µm) than the milled (17.31 ± 3.39 µm). 3D-printed and milled zirconia crowns were comparable to each other in terms of internal fit and marginal adaptation. The trueness of the occlusal and axial surfaces of 3D-printed crowns was better, whereas the trueness of fitting surface of milled crowns was better. 3D-printed crowns provided a higher level of precision than milled crowns. Although the internal and marginal fit of both production techniques were comparable, 3D printing of zirconia produced more precise crowns.
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Abualsaud R, Abussaud M, Assudmi Y, Aljoaib G, Khaled A, Alalawi H, Akhtar S, Matin A, Gad MM. Physiomechanical and Surface Characteristics of 3D-Printed Zirconia: An In Vitro Study. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6988. [PMID: 36234329 PMCID: PMC9572578 DOI: 10.3390/ma15196988] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/01/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
The objective of this study is to examine the physiomechanical and surface properties of 3D-printed zirconia in comparison to milled zirconia. A total of 80 disc-shaped (14 × 1.5 ± 0.2 mm) specimens (20 milled and 60 3D-printed (at three different orientations; horizontal, vertical, and tilted)) were manufactured from 3-mol% yttria-stabilized tetragonal zirconia. Five specimens per group were evaluated for crystalline phase, grain size, density, porosity, surface roughness, wettability, microhardness, and SEM analysis of the surface. Biaxial flexural strength (BFS) was measured (n = 15) followed by Weibull analysis and SEM of fractured surfaces. Statistical analysis was performed using one-way ANOVA and Tukey’s post hoc test at α = 0.05. All groups showed a predominant tetragonal phase, with a 450 nm average grain size. There was no significant difference between groups with regards to density, porosity, and microhardness (p > 0.05). The tilted group had the highest surface roughness (0.688 ± 0.080 µm), significantly different from the milled (p = 0.012). The horizontal group presented the highest contact angle (89.11 ± 5.22°), significantly different from the milled and tilted (p > 0.05). The BFS of the milled group (1507.27 ± 340.10 MPa) was significantly higher than all other groups (p < 0.01), while vertical and tilted had a similar BFS that was significantly lower than horizontal (p < 0.005). The highest and lowest Weibull modulus were seen with tilted and milled, respectively. Physical properties of all groups were comparable. The surface roughness of the tilted group was higher than milled. The horizontal group had the highest hydrophobicity. Printing orientations influenced the flexural strength of 3D-printed zirconia. Clinical implications: This study demonstrates how the printing orientation affects the physiomechanical characteristics of printed zirconia.
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Affiliation(s)
- Reem Abualsaud
- Substitutive Dental Sciences Department, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Maissan Abussaud
- Intern, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Yara Assudmi
- Intern, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Ghadah Aljoaib
- Intern, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Abrar Khaled
- Intern, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Haidar Alalawi
- Substitutive Dental Sciences Department, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Sultan Akhtar
- Department of Biophysics, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Asif Matin
- IRC Membranes & Water Security, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
| | - Mohammed M. Gad
- Substitutive Dental Sciences Department, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
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Abstract
The purpose of this study is to present current dental ceramic materials and processing methods. The clinical indication was emphasized on basis of the material's microstructure and composition. Studies of ceramic characterization were also discussed, as they impact the clinical indication and serve as a parameter for the development of new materials. The novel strategies were mostly found aiming to mimic the natural dental structures, provide mechanical reliability, and develop predictable restorations in terms of adaptation and design.
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Affiliation(s)
- Atais Bacchi
- Post-Graduate Program in Dentistry, Paulo Picanço School of Dentistry, Rua Joaquim Sá 900, Fortaleza, Ceará 60325-218, Brazil.
| | - Paulo Francisco Cesar
- Department of Biomaterials and Oral Biology, University of São Paulo - USP. Av Prof Lineu Prestes, 2227. Cidade Universitária, São Paulo, São Paulo 05508-000, Brazil
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28
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Valenti C, Isabella Federici M, Masciotti F, Marinucci L, Xhimitiku I, Cianetti S, Pagano S. Mechanical properties of 3D-printed prosthetic materials compared with milled and conventional processing: A systematic review and meta-analysis of in vitro studies. J Prosthet Dent 2022:S0022-3913(22)00415-2. [PMID: 35934576 DOI: 10.1016/j.prosdent.2022.06.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 06/22/2022] [Accepted: 06/22/2022] [Indexed: 11/23/2022]
Abstract
STATEMENT OF PROBLEM Three-dimensional (3D) additive manufacturing (AM) is an evolving technology in dentistry, proposed as an alternative to subtractive milling manufacture (MM) or conventional processing. However, a systematic review of the use of AM technology instead of milling or conventional processing is lacking. PURPOSE The purpose of this systematic review and meta-analysis was to evaluate the mechanical properties of 3D-printed prosthetic materials compared with MM and conventional techniques. MATERIAL AND METHODS An electronic search of the literature was conducted on the MEDLINE (via PubMed), Scopus, and Web of Science databases. The inclusion criteria were in vitro studies published in the last 5 years, in English or Italian, and with 3D AM printed dental prosthetic materials. Data extraction was focused on dental prosthetic materials (ceramics, polymers, and metals) and their mechanical properties: flexural strength, fracture load, hardness, roughness, removable partial denture (RPD) fit accuracy, trueness, marginal discrepancy, and internal fit. Data considered homogenous were subjected to meta-analysis using the Stata17 statistical software program (95% confidence interval [CI]; α=.05). Since all variables were continuous, the Hedge g measure was calculated. A fixed-effects model was used for I2=0%, while the statistical analysis was conducted using a random-effects model with I2>0%. RESULTS From a total of 3624 articles, 2855 studies were selected, and 76 studies included after full-text reading. The roughness of AM-printed ceramics generally increased compared with that of conventional processing while the marginal discrepancy was comparable both for ceramics and polymers. The flexural strength, hardness, and fracture load of AM-printed polymers were statistically lower than those of the conventional group (P<.05). No significant difference was detected in terms of hardness, roughness, marginal discrepancy, fracture load, trueness, or internal fit between the AM and MM techniques (P>.05). Milling techniques showed significantly higher values of flexural strength (Hedge g=-3.88; 95% CI, -7.20 to -0.58; P=.02), also after aging (Hedge g=-3.29; 95% CI, -6.41 to -0.17; P=.04), compared with AM printing. CONCLUSIONS AM is comparable with MM in terms of mechanical properties, in particular with polymeric materials. The flexural strength of AM-printed prostheses is lower than with conventional and MM techniques, as are the parameters of hardness and fracture load, while the marginal discrepancy is similar to that of MM and conventional techniques. AM prostheses are commonly used for interim crowns and fixed partial dentures, as their rigidity and fracture resistance cannot support mastication forces for extended periods. More comparative studies are needed.
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Affiliation(s)
- Chiara Valenti
- Graduate student, Department of Medicine and Surgery, Odontostomatological University Centre, University of Perugia, Perugia, Italy
| | - Maria Isabella Federici
- Graduate student, Department of Medicine and Surgery, Odontostomatological University Centre, University of Perugia, Perugia, Italy
| | - Francesca Masciotti
- Student, Department of Medicine and Surgery, Odontostomatological University Centre, University of Perugia, Perugia, Italy
| | - Lorella Marinucci
- Researcher, Section of Biosciences and Medical Embryology, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Iva Xhimitiku
- PhD student, Centro di Ateneo di Studi e Attività Spaziali "Giuseppe Colombo" - CISAS, University of Padua, Padua, Italy
| | - Stefano Cianetti
- Professor, Department of Medicine and Surgery, Odontostomatological University Centre, University of Perugia, Perugia, Italy
| | - Stefano Pagano
- Researcher, Department of Medicine and Surgery, Odontostomatological University Centre, University of Perugia, Perugia, Italy.
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Zenthöfer A, Schwindling FS, Schmitt C, Ilani A, Zehender N, Rammelsberg P, Rues S. Strength and reliability of zirconia fabricated by additive manufacturing technology. Dent Mater 2022; 38:1565-1574. [PMID: 35933222 DOI: 10.1016/j.dental.2022.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 06/29/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022]
Abstract
OBJECTIVES To test strength and reliability of 3D printed compared to milled zirconia. METHODS Cylindrical specimens were fabricated from milled (group G1; e.max ZirCAD LT) and from 3D printed (group G2; LithaCon 3Y 230) 3-mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP). While G1 and G2 were sintered in one step, a further series (G3) of 3D printed 3Y-TZP was sintered in two steps including intermediate color infiltration. In each group, two different conditioning strategies were applied (n ≥ 20 samples/subgroup): (1) final polishing with #1200 diamond discs according to ISO 6872, and (2) final polishing with #220 diamond discs resulting in imperfectly polished surfaces. All samples were tested to fracture with a universal testing device (cross-head speed: 1 mm/min). Characteristic strengths and Weibull moduli were calculated. Effects were analyzed by means of either ANOVA (homocedastic data) or Welch ANOVA (heterocedastic data). RESULTS For samples conditioned according to ISO 6872, mean flexural strengths were 1462 ± 105 MPa (G1), 1369 ± 280 MPa (G2), and 1197 ± 317 MPa (G3). For the imperfectly polished subgroups, strength values were 1461 ± 121 MPa (G1), 1349 ± 332 MPa (G2), and 1271 ± 272 MPa (G3). Although all groups showed high mean strength values, the reliability of milled zirconia (Weibull moduli 14 < m <16) outperformed that of the 3D-printed material (3 < m <6). SIGNIFICANCE Even after color infiltration in a partially sintered state, the tested 3D printed zirconia exceeded the ISO flexural strength criteria for all types of fixed ceramic restorations by far (800 MPa for class 6, ISO 6872), indicating its high potential for clinical use. Further optimization of the internal material structure after sintering might improve the reliability of 3D printed zirconia which is currently inferior to that of milled zirconia.
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Affiliation(s)
- Andreas Zenthöfer
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Franz Sebastian Schwindling
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Clemens Schmitt
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Ali Ilani
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Nathalie Zehender
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Stefan Rues
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany.
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Ma Q, Ding Q, Zhang L, Sun Y, Xie Q. Surface characteristics and flexural strength of Porous-Surface designed zirconia manufactured via stereolithography. J Prosthodont 2022; 32:e81-e89. [PMID: 35778958 DOI: 10.1111/jopr.13565] [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: 05/02/2022] [Accepted: 06/17/2022] [Indexed: 12/01/2022] Open
Abstract
PURPOSE To design and fabricate zirconia bars with porous surfaces using stereolithography and evaluate their surface characteristics and flexural strengths. METHODS Five groups of zirconia bars (20 mm × 4 mm × 2 mm) with interconnected porous surfaces were designed and manufactured: (i) 400-μm pore size and 50% porosity (D400-P50 group), (ii) 400-μm pore size and 30% porosity (D400-P30 group), (iii) 200-μm pore size and 50% porosity (D200-P50 group), (iv) 200-μm pore size and 30% porosity (D200-P30 group), and (v) 100-μm pore size and 30% porosity (D100-P30 group). Zirconia bars without a porous surface (NP) were used as controls. The surface topographies and pore structures were investigated using scanning electron microscopy and three-dimensional laser microscopy. The printed porosity was calculated using the Archimedes method. Fifteen specimens from each group were subjected to a three-point bending test according to the ISO 6872:2015 standard. A Weibull analysis was performed, and the fractured surfaces were examined using scanning electron microscopy. RESULTS Zirconia bars with porous surfaces were designed and successfully manufactured. The designed pore size, porosity, and shape of the printed pores were approximately achieved for all the porous surfaces. The flexural strength of the control group was significantly higher than those of the groups with porous surfaces (p < 0.001). For the same porosity, groups with a pore size of 400 μm exhibited a lower flexural strength than the other groups (p<0.001). Additionally, for the same pore-size design, the flexural strengths of group D400-P50 and D400-P30 exhibited no significant differences (p = 0.150), while the flexural strengths of D200-P30 were significantly higher than that of D200-P50 group (p = 0.043). The control group and D400-P50 group had higher Weibull moduli than the other groups. The fractography of the specimens with porous surfaces indicated more than one crack origin, mainly owing to defects, including pores and cracks. CONCLUSION Zirconia bars with porous surfaces were successfully designed and fabricated using the stereolithography technique. Although porous surfaces may be advantageous for osteogenesis, the porous-surface design can reduce the flexural strength of the printed zirconia bars. By reducing the pore size, controlling the porosity, and improving the printing accuracy, a higher strength can be achieved. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Quanquan Ma
- Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Center 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 & Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health & NMPA Key Laboratory for Dental Materials, Beijing, China
| | - Qian Ding
- Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Center 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 & Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health & NMPA Key Laboratory for Dental Materials, Beijing, China.,Foshan (Southern China) Institute for New Materials, Guangdong, China
| | - Lei Zhang
- Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Center 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 & Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health & NMPA Key Laboratory for Dental Materials, Beijing, China
| | - Yuchun Sun
- Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Research Center of Engineering and Technology for Digital Dentistry, Beijing, China
| | - Qiufei Xie
- Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Center 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 & Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health & NMPA Key Laboratory for Dental Materials, Beijing, China
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31
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Al Hamad KQ, Al-Rashdan BA, Ayyad JQ, Al Omrani LM, Sharoh AM, Al Nimri AM, Al-Kaff FT. Additive Manufacturing of Dental Ceramics: A Systematic Review and Meta-Analysis. J Prosthodont 2022; 31:e67-e86. [PMID: 35675133 DOI: 10.1111/jopr.13553] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/29/2022] [Indexed: 12/25/2022] Open
Abstract
PURPOSE The purpose of this systematic review and meta-analysis was to evaluate the effect of using additive manufacturing (AM) for dental ceramic fabrication in comparison with subtractive manufacturing (SM), and to evaluate the effect of the type of AM technology on dental ceramic fabrication. MATERIALS AND METHODS A search was conducted electronically in MEDLINE (via PubMed), EBSCOhost, Scopus, and Cochran Library databases, and also by other methods (table of contents screening, backward and forward citations, and grey literature search) up to February 12, 2022, to identify records evaluating additive manufacturing of ceramics for dental purposes in comparison with subtractive manufacturing. A minimum of 2 review authors conducted tstudy selection, quality assessment, and data extraction. Quality assessment was performed with Joanna Briggs Institute tool, and the quantitative synthesis was performed with the Comprehensive Meta-Analysis program (CMA, Biostat Inc). Hedges's g for effect size was calculated, with 0.2 as small, 0.5 as medium, and 0.8 as large. Heterogeneity was assessed with I2 and prediction interval (PI) statistics. Publication bias was investigated with funnel plots and grey literature search. Certainty of evidence was assessed with the Grading of Recommendations: Assessment, Development, and Evaluation (GRADE) tool. RESULTS A total of 28 studies were included for the qualitative and quantitative synthesis; 11 in vitro studies on accuracy, 1 in vivo study on color, and 16 in vitro studies on physical and mechanical properties. Meta-analysis showed overall higher accuracy for SM compared with AM, with medium effect size (0.679, CI: 0.173 to 1.185, p = 0.009) and also for marginal (g = 1.05, CI: 0.344 to 1.760, p = 0.004), occlusal (g = 2.24, CI: 0.718 to 3.766, p = 0.004), and total (g = 4.544, CI: -0.234 to 9.323, p = 0.062) with large effect size; whereas AM had higher accuracy than SM with small effect size for the external (g = -0.238, CI: -1.215 to 0.739), p = 0.633), and internal (g = -0.403, CI: -1.273 to 0.467, p = 0.364) surfaces. For technology, self-glazed zirconia protocol had the smallest effect size (g = -0.049, CI: -0.878 to 0.78, p = 0.907), followed by stereolithography (g = 0.305, CI: -0.289 to 0.9, p = 0.314), and digital light processing (g = 1.819, CI: 0.662 to 2.976, p = 0.002) technologies. Flexural strength was higher for ceramics made by SM in comparison to AM with large effect size (g = -2.868, CI: -4.371 to -1.365, p < 0.001). Only 1 study reported on color, favoring ceramics made through combined AM and SM. CONCLUSIONS Subtractive manufacturing had better overall accuracy, particularly for the marginal and occlusal areas, higher flexural strength, and more favorable hardness, fracture toughness, porosity, fatigue, and volumetric shrinkage; whereas AM had more favorable elastic modulus and wettability. Both methods had favorable biocompatibility. All studies on accuracy and mechanical properties were in vitro, with high heterogeneity and low to very low certainty of evidence. There is a lack of studies on color match and esthetics.
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Affiliation(s)
- Khaled Q Al Hamad
- Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan
| | | | - Jad Q Ayyad
- Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan
| | - Leen M Al Omrani
- Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan
| | - Ayat M Sharoh
- Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan
| | - Adnan M Al Nimri
- Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan
| | - Fatma T Al-Kaff
- Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan
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Comments on "Esthetic appearances of anatomic contour zirconia crowns made by additive wet deposition and subtractive dry milling: A self-controlled clinical trial". J Prosthet Dent 2022; 127:945-946. [PMID: 35489837 DOI: 10.1016/j.prosdent.2022.01.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 11/22/2022]
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Kim YK, Han JS, Yoon HI. Evaluation of intaglio surface trueness, wear, and fracture resistance of zirconia crown under simulated mastication: a comparative analysis between subtractive and additive manufacturing. J Adv Prosthodont 2022; 14:122-132. [PMID: 35601347 PMCID: PMC9095451 DOI: 10.4047/jap.2022.14.2.122] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 11/08/2022] Open
Abstract
PURPOSE This in-vitro analysis aimed to compare the intaglio trueness, the antagonist's wear volume loss, and fracture load of various single-unit zirconia prostheses fabricated by different manufacturing techniques. MATERIALS AND METHODS Zirconia crowns were prepared into four different groups (n = 14 per group) according to the manufacturing techniques and generations of the materials. The intaglio surface trueness (root-mean-square estimates, RMS) of the crown was measured at the marginal, axial, occlusal, and inner surface areas. Half of the specimens were artificially aged in the chewing simulator with 120,000 cycles, and the antagonist's volume loss after aging was calculated. The fracture load for each crown group was measured before and after hydrothermal aging. The intaglio trueness was evaluated with Welch's ANOVA and the antagonist's volume loss was assessed by the Kruskal-Wallis tests. The effects of manufacturing and aging on the fracture resistance of the tested zirconia crowns were determined by two-way ANOVA. RESULTS The trueness analysis of the crown intaglio surfaces showed surface deviation (RMS) within 50 µm, regardless of the manufacturing methods (P = .053). After simulated mastication, no significant differences in the volume loss of the antagonists were observed among the zirconia groups (P = .946). The manufacturing methods and simulated chewing had statistically significant effects on the fracture resistance (P < .001). CONCLUSION The intaglio surface trueness, fracture resistance, and antagonist's wear volume of the additively manufactured 3Y-TZP crown were clinically acceptable, as compared with those of the 4Y- or 5Y-PSZ crowns produced by subtractive milling.
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Affiliation(s)
- Yong-Kyu Kim
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Jung-Suk Han
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Hyung-In Yoon
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
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Alammar A, Kois JC, Revilla-León M, Att W. Additive Manufacturing Technologies: Current Status and Future Perspectives. J Prosthodont 2022; 31:4-12. [PMID: 35313022 DOI: 10.1111/jopr.13477] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2022] [Indexed: 12/11/2022] Open
Abstract
A review of the main additive manufacturing technologies including vat-polymerization, material extrusion, material jetting, binder jetting, powder-based fusion, sheet lamination, and direct energy deposition is provided. Additionally, the dental applications of polymer, metal, and ceramic printing technologies are discussed.
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Affiliation(s)
| | - John C Kois
- Kois Center, Seattle, WA.,Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA.,Private Practice, Seattle, WA
| | - Marta Revilla-León
- Kois Center, Seattle, WA.,Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA.,Department of Prosthodontics, Tufts University School of Dental Medicine, Boston, MA
| | - Wael Att
- Department of Prosthodontics, Tufts University School of Dental Medicine, Boston, MA
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35
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Dyakonenko EE, Parunov VA, Sakhabieva DA, Lebedenko IY. [Manufacturing of zirconia restorations by means of additive fabrication. Part I]. STOMATOLOGIIA 2022; 101:91-97. [PMID: 36562374 DOI: 10.17116/stomat202210106191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Additive fabrication or layer-by-layer synthesis technologies is one of the most dynamically developing areas of digital production. Modern additive technologies can be used to fabricate zirconia-based restorations. The first part of this article will present the fabrication of zirconia restorations using additive technologies such as stereolithography, digital light processing, selective laser sintering, selective laser melting and inkjet printing, as well as the advantages and disadvantages of the mentioned technologies.
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Affiliation(s)
- E E Dyakonenko
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia
| | - V A Parunov
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia.,Peoples' Friendship University of Russia, Moscow, Russia
| | - D A Sakhabieva
- Peoples' Friendship University of Russia, Moscow, Russia
| | - I Yu Lebedenko
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia.,Peoples' Friendship University of Russia, Moscow, Russia
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36
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Lyu H, Murakami N, Yamazaki T, Wada J, Utsumi M, Wakabayashi N. Evaluation of PEEK and zirconia occlusal rest designs for removable partial dentures based on finite element analysis. J Prosthodont Res 2022; 67:196-205. [PMID: 35644568 DOI: 10.2186/jpr.jpr_d_22_00011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Purpose We aimed to assess removable partial denture occlusal rests composed of polyether-ether-ketone (PEEK) and zirconia, using finite element analysis.Methods Three-dimensional PEEK and zirconia rest models, including the occlusal rest (1.5 mm thickness at the basal portion, 3.0 mm width) and minor connector (1.5 mm thickness, 6.0 mm height), and rest seat models with mechanical properties of enamel were constructed. The radius of transitional curvature between the rest and minor connector was 0.1-0.5 mm. The rest and rest seat model interfaces were set as frictional contacts (μ = 0.1), and the base of the rest seat model was restrained in all the directions. A 100 N downward load was applied perpendicular to the bottom surface of the minor connector. The maximum value of the first principal stress (Max-S1) was compared to the flexural and fatigue strengths of each material. Occlusal rests with 1.0-2.0 mm thickness, 2.0-3.5 mm width, and 0.5 mm radius of transitional curvature were analyzed.Results Max-S1 was observed at the transitional part and decreased with increasing radius of the transitional curvature, rest width, and thickness. PEEK rests with at least 1.5 mm thicknesses and 3.0 mm widths showed lower Max-S1 than the flexural strength. Max-S1 of all PEEK rests exceeded the PEEK fatigue strength, whereas Max-S1 of the zirconia rests was lower than the zirconia fatigue strength.Conclusions Zirconia occlusal rests with conventional metal rest designs have sufficient fatigue strength. PEEK occlusal rests have insufficient fatigue strength and may not withstand repeated mastication.
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Affiliation(s)
- Huaxin Lyu
- Advanced Prosthodontics, Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Natsuko Murakami
- Advanced Prosthodontics, Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Toshiki Yamazaki
- Advanced Prosthodontics, Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Junichiro Wada
- Advanced Prosthodontics, Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Miona Utsumi
- Advanced Prosthodontics, Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Noriyuki Wakabayashi
- Advanced Prosthodontics, Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
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Baysal N, Tuğba Kalyoncuoğlu Ü, Ayyıldız S. Mechanical Properties and Bond Strength of Additively Manufactured and Milled Dental Zirconia: A Pilot Study. J Prosthodont 2021; 31:629-634. [PMID: 34940979 DOI: 10.1111/jopr.13472] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2021] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To evaluate and compare the mechanical properties and ceramic bond of additively manufactured and milled dental zirconia materials. MATERIALS AND METHODS Disc (r = 10 mm, h = 2 mm) and bar (254) shaped milled (M group) (Nacera Pearl; Doceram) and additively manufactured (AM group) (NanoParticul Jetting; XJet, Carmel 1400) zirconia specimens were prepared for 2 experimental groups. Ceramic was applied to the disc specimens (h = 4 mm, r = 6 mm) (n =9) and their shear bond strength (SBS) was measured. The surface morphology of disc specimens was analyzed with a scanning electron microscope (SEM). The Vickers microhardness (Vh), surface roughness (Ra), and three-point flexural strength (FS) of bar specimens (n = 9) were measured. Results were statistically analyzed with Mann-Whitney U-test (α = 0.05) RESULTS: : Significant differences were found in FS and Vh values of the M and AM groups. M group (1501.4 ± 60.1 HV1) showed a significantly higher Vh value than the AM group (1169.2 ± 48.4 HV1) (p < 0.001). FS of the M group (1287.5 ± 115.2 MPa) exhibited significantly high value than the AM (1030.0 ± 29.2 MPa) group (p < 0.001). Statistically, no significant differences were seen in SBS and Ra values of the M and AM groups. CONCLUSION Within the limitations of this in vitro study, the manufacturing technique affected the mechanical properties of the zirconia materials. AM zirconia material showed lower Vh and FS values than M zirconia. Additionally AM zirconia demonstrated adequate bond strength with dental ceramic. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Nurten Baysal
- Department of Prosthodontics, Faculty of Gülhane Dentistry, University of Health Sciences Turkey, Ankara, Turkey
| | - Ülkü Tuğba Kalyoncuoğlu
- Department of Prosthodontics, Faculty of Gülhane Dentistry, University of Health Sciences Turkey, Ankara, Turkey
| | - Simel Ayyıldız
- Department of Prosthodontics, Faculty of Gülhane Dentistry, University of Health Sciences Turkey, Ankara, Turkey
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Gatto ML, Groppo R, Furlani M, Giuliani A, Mangano C, Mangano F. Lithography-based Ceramic Manufacturing (LCM) versus Milled Zirconia Blocks under uniaxial compressive loading: An in vitro comparative study. J Dent 2021; 116:103886. [PMID: 34762988 DOI: 10.1016/j.jdent.2021.103886] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/21/2021] [Accepted: 10/28/2021] [Indexed: 10/19/2022] Open
Abstract
AIM This in vitro study aimed to compare the mechanical performance of 3D printed versus milled zirconia blocks, when subjected to uniaxial compression load, and to investigate the microstructural characteristics of the 3D printed samples, before and after the application of the load. METHODS Twenty zirconia blocks (5 × 5 × 5mm3) were prepared: 10 (tests) were 3D printed with a Lithography-based Ceramic Manufacturing (LCM) printer (Cerafab S65®, Lithoz, Vienna, Austria), and 10 (controls) were milled with a 5-axis milling machine (DWX-52D®, DGShape, a Roland Company, Hamamatsu, Japan). Compression tests were carried out on all samples, using a load cell of 30 kN and crosshead speed of 0.5 mm/min, in according to the ASTM C1424-15. The elastic modulus of the material was calculated from stress/strain curve by taking compressive stress values between 50 MPa and 100 MPa. Compression data obtained were plotted as stress-strain curves. Finally, the 3D printed test samples were also observed by VEGA3 Tescan scanning electron microscope (SEM) to detect the presence of eventual defects on surface before and after compression. A statistical analysis was performed to compare the elastic modulus and the deformation in compression at maximum load of the test samples that did not break and the control samples. RESULTS Under mechanical compression, four of the test samples reached failure, whereas all the control samples did not reach failure at the limit of the load cell. However, the 3D printed samples that did not break revealed interesting properties, such as a better modulus of elasticity (p = 0.15) and a lower tendency to deformation under compression (p<0.001), when compared to the milled ones. CONCLUSIONS Within the limits of this study (experimental setting, in vitro design, only one type of force applied) milled zirconia blocks were found more resistant to compression forces than 3D printed ones.
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Affiliation(s)
- Maria Laura Gatto
- Department SIMAU, Università Politecnica delle Marche, Ancona, Italy
| | - Riccardo Groppo
- Department of Engineering "Enzo Ferrari", Università di Modena e Reggio Emilia, Italy
| | - Michele Furlani
- Department of Clinical Sciences, Università Politecnica delle Marche, Ancona, Italy
| | - Alessandra Giuliani
- Department of Clinical Sciences, Università Politecnica delle Marche, Ancona, Italy
| | - Carlo Mangano
- Department of Dental Sciences, San Raffaele University, Milan, Italy
| | - Francesco Mangano
- Department of Pediatric, Preventive Dentistry and Orthodontics, Sechenov First State Medical University, Moscow, Russia.
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Zandinejad A, Das O, Barmak AB, Kuttolamadom M, Revilla-León M. The Flexural Strength and Flexural Modulus of Stereolithography Additively Manufactured Zirconia with Different Porosities. J Prosthodont 2021; 31:434-440. [PMID: 34580962 DOI: 10.1111/jopr.13430] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 09/01/2021] [Accepted: 09/09/2021] [Indexed: 11/28/2022] Open
Abstract
PURPOSE Additive manufacturing (AM) technologies are capable of fabricating complex geometries with different porosities. However, the effect of such porosities on mechanical properties of stereolithography (SLA) AM zirconia with different porosities is unclear. The purpose of this in vitro study was to investigate the mechanical properties namely flexural strength, and flexural modulus of AM zirconia with different porosities. MATERIALS AND METHODS A bar (25 × 4 × 3 mm) for flexural strength test (ISO standard 6872/2015) was designed by CAD software program and standard tessellation language (STL) file was obtained. The STL file was used to fabricate a total of 80 bars in four groups. Three experimental groups each containing 20 samples were manufactured using an SLA ceramic printer (CeraMaker 900; 3DCeram Co) and zirconia material (3DMix ZrO2 paste; 3DCeram Co) with different sintering post processing to achieve different porosities including 0%-porosity (AMZ0), 20%-porosity (AMZ20), and 40%-porosity (AMZ40). The same STL file was used for subtractive manufacturing or milling of 20 zirconia bars as control group (CNCZ) with the same dimensions using a commercial zirconia. Three-point bending tests were performed for all groups following ISO standard 6872/2015 specification using a universal testing machine. Outcomes measured included load at fracture, mean flexural strength, and flexural modulus and they were compared across the experimental groups using a one-way ANOVA. Post hoc pair wise comparison between each pair of the groups were performed using Tukey test. RESULTS There was a significant difference between the four groups, in terms of fracture load, flexural strength and flexural modulus using one-way ANOVA. AM zirconia with 0% porosity (AMZ0) showed the highest value for fracture load (1132.7 ± 220.6 N), flexural strength (755.1 ± 147.1 MPa) and flexural modulus (41,273 ± 2193 MPa) and AM zirconia with 40% porosity (AMZ40) showed the lowest fracture load (72.13 ± 13.42 N), flexural strength (48.09 ± 8.95 MPa) and flexural modulus (7177 ± 506 MPa). Tukey's pairwise comparisons detected a significant difference between all the possible pairs for all variables except flexural modulus between AMZ0 and CNCZ. The Weibull moduli presented the lowest value for AMZ20 (4.4) followed by AMZ40 (6.1), AMZ0 (6.1), and the highest value was for CNCZ (8.1). CONCLUSION AM zirconia with 0% porosity showed significantly higher flexural strength and flexural modulus when compared to milled and AM zirconia with 20% and 40% porosities.
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Affiliation(s)
| | - Omprakash Das
- College of Engineering, Texas A&M University, College Station, TX
| | | | | | - Marta Revilla-León
- College of Dentistry, Texas A&M University, Dallas, TX.,School of Dentistry, University of Washington, Seattle, WA.,Revilla Research Center, Madrid, Spain
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Khanlar LN, Salazar Rios A, Tahmaseb A, Zandinejad A. Additive Manufacturing of Zirconia Ceramic and Its Application in Clinical Dentistry: A Review. Dent J (Basel) 2021; 9:dj9090104. [PMID: 34562978 PMCID: PMC8469515 DOI: 10.3390/dj9090104] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 08/27/2021] [Accepted: 08/31/2021] [Indexed: 12/02/2022] Open
Abstract
Additive manufacturing (AM) has many advantages and became a valid manufacturing technique for polymers and metals in dentistry. However, its application for dental ceramics is still in process. Among dental ceramics, zirconia is becoming popular and widely used in dentistry mainly due to its outstanding properties. Although subtractive technology or milling is the state of art for manufacturing zirconia restorations but still has shortcomings. Utilizing AM in fabricating ceramics restorations is a new topic for many researchers and companies across the globe and a good understanding of AM of zirconia is essential for dental professional. Therefore, the aim of this narrative review is to illustrate different AM technologies available for processing zirconia and discus their advantages and future potential. A comprehensive literature review was completed to summarize different AM technologies that are available to fabricate zirconia and their clinical application is reported. The results show a promising outcome for utilizing AM of zirconia in restorative, implant and regenerative dentistry. However further improvements and validation is necessary to approve its clinical application.
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Affiliation(s)
- Leila Nasiry Khanlar
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
- Correspondence:
| | - Alma Salazar Rios
- College of Dentistry, Texas A&M University, Dallas, TX 75246, USA; (A.S.R.); (A.Z.)
| | - Ali Tahmaseb
- Department of Oral Maxillofacial Surgery Erasmus Medical Centre, 3015 Rotterdam, The Netherlands;
| | - Amirali Zandinejad
- College of Dentistry, Texas A&M University, Dallas, TX 75246, USA; (A.S.R.); (A.Z.)
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Lerner H, Nagy K, Pranno N, Zarone F, Admakin O, Mangano F. Trueness and precision of 3D-printed versus milled monolithic zirconia crowns: An in vitro study. J Dent 2021; 113:103792. [PMID: 34481929 DOI: 10.1016/j.jdent.2021.103792] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/14/2021] [Accepted: 08/18/2021] [Indexed: 11/28/2022] Open
Abstract
PURPOSE To compare the trueness and precision of 3D-printed versus milled monolithic zirconia crowns (MZCs). METHODS A model of a maxilla with a prepared premolar was scanned with an industrial scanner (ATOSQ®, Gom) and an MZC was designed in computer-assisted-design (CAD) software (DentalCad®, Exocad). From that standard tessellation language (STL) file, 10 MZCs (test) were 3D-printed with a Lithography-based Ceramic Manufacturing (LCM) printer (CerafabS65®, Lithoz) and 10 MZCs (control) were milled using a 5-axis machine (DWX-52D®, DGShape). All MZCs were sintered and scanned with the aforementioned scanner. The surface data of each sample (overall crown, marginal area, occlusal surface) were superimposed to the original CAD file (ControlX®, Geomagic) to evaluate trueness: (90-10)/2, absolute average (ABS AVG) and root mean square (RMS) values were obtained for test and control groups (MathLab®, Mathworks) and used for analysis. Finally, the clinical precision (marginal adaptation, interproximal contacts) of test and control MZCs was investigated on a split-cast model printed (Solflex350®, Voco) from the CAD project, and compared. RESULTS The milled MZCs had a significantly higher trueness than the 3D-printed ones, overall [(90-10)/2 printed 37.8 µm vs milled 21.2 µm; ABS AVG printed 27.2 µm vs milled 15.1 µm; RMS printed 33.2 µm vs milled 20.5 µm; p = 0.000005], at the margins [(90-10)/2 printed 25.6 µm vs milled 12.4 µm; ABS AVG printed 17.8 µm vs milled 9.4 µm; RMS printed 22.8 µm vs milled 15.6 µm; p= 0.000011] and at the occlusal level [(90-10)/2 printed 50.4 µm vs milled 21.9 µm; ABS AVG printed 29.6 µm vs milled 14.7 µm; RMS printed 38.9 µm vs milled 22.5 µm; p = 0.000005]. However, with regard to precision, both test and control groups scored highly, with no significant difference either in the quality of interproximal contact points (p = 0.355) or marginal closure (p = 0.355). CONCLUSIONS Milled MZCs had a statistically higher trueness than 3D-printed ones; all crowns, however, showed high precision, compatible with the clinical use. CLINICAL SIGNIFICANCE Although milled MZCs remain more accurate than 3D-printed ones, the LCM technique seems able to guarantee the production of clinically precise zirconia crowns.
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Affiliation(s)
- Henriette Lerner
- Department of Oral Surgery, University of Szeged, Szeged, Hungary.
| | - Katalin Nagy
- Department of Oral Surgery, University of Szeged, Szeged, Hungary.
| | - Nicola Pranno
- Department of Oral and Maxillofacial Sciences, Sapienza University, Rome, Italy.
| | - Fernando Zarone
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University Federico II, Naples, Italy.
| | - Oleg Admakin
- Department of Pediatric, Preventive Dentistry and Orthodontics, Sechenov First State Medical University, Moscow, Russia.
| | - Francesco Mangano
- Department of Pediatric, Preventive Dentistry and Orthodontics, Sechenov First State Medical University, Moscow, Russia.
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Kim JC, Yeo ISL. Bone Response to Conventional Titanium Implants and New Zirconia Implants Produced by Additive Manufacturing. MATERIALS 2021; 14:ma14164405. [PMID: 34442927 PMCID: PMC8401228 DOI: 10.3390/ma14164405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 12/18/2022]
Abstract
The aim of the present study was to evaluate the in vivo bone response to an additively manufactured zirconia surface compared to osseointegration into titanium (Ti) surfaces. Scanning electron microscopy, confocal laser scanning microscopy, and electron spectroscopy for chemical analysis were performed to assess the surface characteristics of implant specimens. For the in vivo evaluation, eight Ti implants and eight 3D-printed zirconia implants were used. The surface of four Ti implants was sandblasted, large-grit, and acid-etched (Ti-SLA group), while those of the other four Ti implants were left untreated (Ti-turned group). The zirconia implants had no further surface modification. Implants were placed into the tibiae of four rabbits; two received the Ti-SLA and zirconia implants and the other two received Ti-turned and zirconia implants. The experimental animals were sacrificed after four weeks of surgery, and the undecalcified microscopic slides were prepared. The bone–implant interface was analyzed by histomorphometry to evaluate the bone response. The degree of surface roughness showed that Ti-SLA was the highest, followed by zirconia and Ti-turned surfaces. The 3D-printed zirconia surface showed similar bone-to-implant contact to the Ti-turned surface, and Ti-SLA had the most bone-to-implant contact. The additively manufactured zirconia implant surface is biocompatible with respect to osseointegration compared to the commercially pure Ti surface.
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Affiliation(s)
- Jin-Cheol Kim
- Department of Prosthodontics, Seoul National University School of Dentistry, Seoul 03080, Korea;
| | - In-Sung Luke Yeo
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul 03080, Korea
- Correspondence: ; Tel.: +82-2-2072-2661; Fax: +82-2-2072-3860
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Additively Manufactured Zirconia for Dental Applications. MATERIALS 2021; 14:ma14133694. [PMID: 34279264 PMCID: PMC8269801 DOI: 10.3390/ma14133694] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 06/27/2021] [Accepted: 06/28/2021] [Indexed: 11/17/2022]
Abstract
We aimed to assess the crystallography, microstructure and flexural strength of zirconia-based ceramics made by stereolithography (SLA). Two additively manufactured 3 mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP: LithaCon 3Y 230, Lithoz; 3D Mix zirconia, 3DCeram Sinto) and one alumina-toughened zirconia (ATZ: 3D Mix ATZ, 3DCeram Sinto) were compared to subtractively manufactured 3Y-TZP (control: LAVA Plus, 3M Oral Care). Crystallographic analysis was conducted by X-ray diffraction. Top surfaces and cross-sections of the subsurface microstructure were characterized using scanning electron microscopy (SEM). Biaxial flexural strength was statistically compared using Weibull analysis. The additively and subtractively manufactured zirconia grades revealed a similar phase composition. The residual porosity of the SLA 3Y-TZPs and ATZ was comparable to that of subtractively manufactured 3Y-TZP. Weibull analysis revealed that the additively manufactured LithaCon 3Y 230 (Lithoz) had a significantly lower biaxial flexural strength than 3D Mix ATZ (3D Ceram Sinto). The biaxial flexural strength of the subtractively manufactured LAVA Plus (3M Oral Care) was in between those of the additively manufactured 3Y-TZPs, with the additively manufactured ATZ significantly outperforming the subtractively manufactured 3Y-TZP. Additively manufactured 3Y-TZP showed comparable crystallography, microstructure and flexural strength as the subtractively manufactured zirconia, thus potentially being a good option for dental implants.
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