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Lin YC, Tarrazzi D, Schoenbaum T, Knoernschild K. Effect of postprocessing parameters on the flexural strength of vat-polymerized additively manufactured interim fixed dental prostheses: A systematic review with postprocessing guidelines. J Prosthet Dent 2024:S0022-3913(24)00497-9. [PMID: 39142995 DOI: 10.1016/j.prosdent.2024.07.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 08/16/2024]
Abstract
STATEMENT OF PROBLEM Limited data exist regarding the effects of postprocessing on the flexural strength of vat-polymerized additively manufactured (AM) interim fixed dental prostheses. PURPOSE The purpose of this systematic review was to determine how the postprocessing workflow affects the mechanical properties of vat-polymerized additively manufactured interim fixed dental prostheses and to establish clinical guidelines. MATERIAL AND METHODS The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. The population, intervention, comparison, and outcome (PICO) question was "For vat-polymerized additively manufactured interim fixed dental prostheses (P), does varying the postprocessing workflow/ protocol (I and C) affect mechanical properties/physical properties/flexural strength (O)?" Searches were conducted in 3 databases: PubMed/Medline, EMBASE, and Web of Science, with 2 investigators performing the title and abstract screening and setting the inclusion and exclusion criteria to identify publications. The risk of bias was evaluated by applying the Joanna Briggs Institute Critical Appraisal Checklist for Quasi-Experimental Studies (nonrandomized experimental studies). The reported independent variables of rinse solution, rinse time, and polymerization time on the flexural strength results were extracted for qualitative review. RESULTS The initial search identified 149 records, with 12 in vitro studies meeting the inclusion criteria. Significant heterogeneity was observed in the manufacturing process and materials. Eleven of 12 included studies reported flexural strength above 100 MPa when following the manufacturer's recommendation. Postprocessing rinsing ranged from 5 seconds to 90 minutes, with potentially reduced flexural strength with extended rinsing. A rinse of 5 to 10 minutes was recommended for optimal mechanical properties, degree of conversion, and biocompatibility. Isopropyl alcohol (IPA) and tripropylene glycol monomethyl ether (TPM) were the most investigated rising solutions, while experimental solutions including 99.5% acetone and 100% bio-ethyl alcohol reportedly decreased flexural strength. Polymerization time and intensity correlated positively with the flexural strength, whereas an artificial aging process reduced the flexural strength. CONCLUSIONS Heterogeneity existed in the reported postprocessing protocols for AM interim fixed prostheses, including manufacturer materials, methods, and study outcomes. While polymerization time and intensity correlated with greater strength, consistent patterns regarding rinsing solution or time were lacking. Rinsing solution, extended rinsing time, and artificial aging may reduce flexural strength. Further investigation is indicated.
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Affiliation(s)
- Yu Chun Lin
- Assistant Professor, Department of Restorative Sciences, Dental College of Georgia at Augusta University, Augusta, GA.
| | - Daler Tarrazzi
- Assistant Professor, Department of Restorative Sciences, Dental College of Georgia at Augusta University, Augusta, GA
| | - Todd Schoenbaum
- Professor, Department of Restorative Sciences, Dental College of Georgia at Augusta University, Augusta, GA
| | - Kent Knoernschild
- Chair and Professor, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, Calif
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Dai J, Luo K, Liu Q, Unkovskiy A, Spintzyk S, Xu S, Li P. Post-processing of a 3D-printed denture base polymer: Impact of a centrifugation method on the surface characteristics, flexural properties, and cytotoxicity. J Dent 2024; 147:105102. [PMID: 38852693 DOI: 10.1016/j.jdent.2024.105102] [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: 11/12/2023] [Revised: 05/22/2024] [Accepted: 05/24/2024] [Indexed: 06/11/2024] Open
Abstract
OBJECTIVES To investigate the impact of a centrifugation method on the surface characteristics, flexural properties, and cytotoxicity of an additively manufactured denture base polymer. METHODS The tested specimens were prepared by digital light processing (DLP). A centrifugation method (CENT) was used to remove the residual uncured resin. In addition, the specimens were post-processed with different post-rinsing solutions: isopropanol (IPA), ethanol (EtOH), and tripropylene glycol monomethyl ether (TPM), respectively. A commercial heat-polymerized polymethyl methacrylate was used as a reference (REF). First, the values of surface topography, arithmetical mean height (Sa), and root mean square height (Sq) were measured. Next, flexural strength (FS) and modulus were evaluated. Finally, cytotoxicity was assessed using an extract test. The data were statistically analyzed using a one-way analysis of variance, followed by Tukey's multiple comparison test for post-hoc analysis. RESULTS The Sa value in the CENT group was lower than in the IPA, EtOH, TPM, and REF groups (p < 0.001). Moreover, the CENT group had lower Sq values than other groups (p < 0.001). The centrifugation method showed a higher FS value (80.92 ± 8.65 MPa) than the EtOH (61.71 ± 12.25 MPa, p < 0.001) and TPM (67.01 ± 9.751 MPa, p = 0.027), while affecting IPA (72.26 ± 8.80 MPa, p = 0.268) and REF (71.39 ± 10.44 MPa, p = 0.231). Also, the centrifugation method showed no evident cytotoxic effects. CONCLUSIONS The surfaces treated with a centrifugation method were relatively smooth. Simultaneously, the flexural strength of denture base polymers was enhanced through centrifugation. Finally, no evident cytotoxic effects could be observed from different post-processing procedures. CLINICAL SIGNIFICANCE The centrifugation method could optimize surface quality and flexural strength of DLP-printed denture base polymers without compromising cytocompatibility, offering an alternative to conventional rinsing post-processing.
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Affiliation(s)
- Jingtao Dai
- Department of Orthodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, South Jiangnan Road No. 366, Guangzhou 510280, China
| | - Ke Luo
- Center of Oral Implantology, Stomatological Hospital, Southern Medical University, South Jiangnan Road No. 366, Guangzhou 510280, China
| | - Qian Liu
- Center of Oral Implantology, Stomatological Hospital, Southern Medical University, South Jiangnan Road No. 366, Guangzhou 510280, China
| | - Alexey Unkovskiy
- Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité - University Hospital, Aßmannshauser Str. 4-6, Berlin 14197, Germany; Department of Dental Surgery, Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya Street, 19с1, Moscow 119146, Russia
| | - Sebastian Spintzyk
- ADMiRE Lab - Additive Manufacturing, intelligent Robotics, Sensors and Engineering, School of Engineering and IT, Carinthia University of Applied Sciences, Europastraße 4, 9524 Villach, Austria
| | - Shulan Xu
- Center of Oral Implantology, Stomatological Hospital, Southern Medical University, South Jiangnan Road No. 366, Guangzhou 510280, China.
| | - Ping Li
- Department of Prosthodontics, School and Hospital of Stomatology, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Guangzhou Medical University, Guangzhou, China; Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Guangzhou Medical University, Guangzhou, China.
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Alamo L, Cassiano FB, Bordini EAF, Stuani VT, Pacheco LE, Gallinari MDO, Souza Costa CA, Mondelli RFL, Soares DG. An organotypic model of oral mucosa cells for the biological assessment of 3D printed resins for interim restorations. J Prosthet Dent 2024; 132:251-259. [PMID: 35864023 DOI: 10.1016/j.prosdent.2022.04.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 04/18/2022] [Accepted: 04/18/2022] [Indexed: 10/17/2022]
Abstract
STATEMENT OF PROBLEM Three-dimensionally (3D) printed resins have become popular as a new class of materials for making interim restorations. However, little is known about how the fabrication parameters can influence biological compatibility with oral tissues. PURPOSE The purpose of this in vitro study was to evaluate the effect of the postpolymerization time on the cytotoxicity of resins for printing interim restorations by using a 3D organotypic model of the oral mucosa. MATERIAL AND METHODS Cylindrical specimens were prepared with conventional acrylic resin (AR), computer-aided design and computer-aided manufacture (CAD-CAM) resin (CC), composite resin (CR), and 2 resins for 3D printing (3DP) marketed as being biocompatible. The 3DPs were submitted to postpolymerization in an ultraviolet (UV) light chamber for 1, 10, or 20 minutes (90 W, 405 nm). Standard specimens of the materials were incubated for 1, 3, and 7 days in close contact with an organotypic model of keratinocytes (NOK-Si) in coculture with gingival fibroblasts (HGF) in a 3D collagen matrix, or directly with 3D HGF cultures. Then, the viability (Live/Dead n=2) and metabolism (Alamar Blue n=6) of the cells were assessed. Spectral scanning of the culture medium was performed to detect released components (n=6) and assessed statistically with ANOVA and the Tukey post hoc test (α=.05). RESULTS Severe reduction of metabolism (>70%) and viability of keratinocytes occurred for 3DP resin postpolymerized for 1 minute in all periods of analysis in a time-dependent manner. The decrease in cell metabolism and viability was moderate for the 3D culture of HGFs in both experimental models, correlated with the intense presence of resin components in the culture medium. The resins postpolymerized for 10 and 20 minutes promoted a mild-moderate cytotoxic effect in the period of 1 day, similar to AR. However, recovery of cell viability occurred at the 7-day incubation period. The 3DP resins submitted to postpolymerization for 20 minutes showed a pattern similar to that of CR and CC at the end of the experiment. CONCLUSIONS The cytotoxic potential of the tested 3DP resins on oral mucosa cells was influenced by postprinting processing, which seemed to have been related with the quantity of residual components leached.
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Affiliation(s)
- Larissa Alamo
- MS student, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo (USP), São Paulo, Brazil
| | - Fernanda Balestrero Cassiano
- PhD student, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo (USP), São Paulo, Brazil
| | - Ester Alves Ferreira Bordini
- Postdoctoral Researcher, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo (USP), São Paulo, Brazil
| | - Vitor Toledo Stuani
- Postdoctoral Researcher, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo (USP), São Paulo, Brazil
| | - Leandro Edgar Pacheco
- PhD student, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo (USP), São Paulo, Brazil
| | - Marjorie de Oliveira Gallinari
- Postdoctoral Researcher, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo (USP), São Paulo, Brazil
| | - Carlos Alberto Souza Costa
- Full Professor, Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, Brazil
| | - Rafael Francisco Lia Mondelli
- Full Professor, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo (USP), São Paulo, Brazil
| | - Diana Gabriela Soares
- Assistant Professor, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo (USP), São Paulo, Brazil.
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Katheng A, Prawatvatchara W, Tonprasong W, Namano S, Kongkon P. Effect of Postrinsing Times and Methods on Surface Roughness, Hardness, and Polymerization of 3D-Printed Photopolymer Resin. Eur J Dent 2024. [PMID: 38759997 DOI: 10.1055/s-0044-1786866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2024] Open
Abstract
OBJECTIVES This in vitro study investigated the effects of different postrinsing times and methods on the surface roughness, surface hardness, and degree of polymerization of materials manufactured via stereolithography (SLA). MATERIALS AND METHODS A total of 288 disk-shaped specimens were manufactured using an SLA three-dimensional (3D) printer. The specimens were randomly divided into nine groups (n = 32) based on rinsing times and methods. The groups were categorized into three rinsing methods: automated, ultrasonic, and hand washing, with rinsing times of 5, 10, and 15 minutes using a 99% isopropanol alcohol as a solvent. Linear roughness (Ra) and area roughness (Sa) were measured using a 3D confocal laser microscopy; the roughness morphology was evaluated by using scanning electron microscopy. Vickers hardness (VHN) tests were performed using a Vickers microhardness tester. Fourier-transform infrared spectrometry was used to determine the degree of conversion of treated specimens. STATISTICAL ANALYSIS Data were statistically analyzed using two-way analysis of variance. The post hoc Tukey tests were conducted to compare the differences between groups (p < 0.05). RESULTS The choice of the rinsing time and method affected the surface properties of the SLA photopolymer resin. The 15 minutes of ultrasonic method exhibited the highest Ra scores (0.86 ± 0.1 µm), while the 15 minutes of automated method presented the highest Sa scores (1.77 ± 0.35 µm). For the VHN test, the 15 minutes of ultrasonic method displayed the highest VHN score (18.26 ± 1.03 kgf/mm2). For the degree of polymerization, the 15 minutes of automated method was initially identified as the most effective (87.22 ± 6.80). CONCLUSION To facilitate the overall surface roughness, surface hardness, and degree of polymerization, the optimal choice of postprocessing rinsing time and method for achieving a clear photopolymer resin was determined to be the ultrasonic method with a rinsing time of 15 minutes.
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Affiliation(s)
- Awutsadaporn Katheng
- Department of Restorative Dentistry, Faculty of Dentistry, Naresuan University, Phitsanulok, Thailand
| | - Wisarut Prawatvatchara
- Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Watcharapong Tonprasong
- Department of Restorative Dentistry, Faculty of Dentistry, Naresuan University, Phitsanulok, Thailand
| | - Sahaprom Namano
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Paweena Kongkon
- Department of Restorative Dentistry, Faculty of Dentistry, Naresuan University, Phitsanulok, Thailand
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Liu Y, Jin G, Lim JH, Kim JE. Effects of washing agents on the mechanical and biocompatibility properties of water-washable 3D printing crown and bridge resin. Sci Rep 2024; 14:9909. [PMID: 38688952 PMCID: PMC11061276 DOI: 10.1038/s41598-024-60450-7] [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: 11/01/2023] [Accepted: 04/23/2024] [Indexed: 05/02/2024] Open
Abstract
Three-dimensional (3D) printing, otherwise known as additive manufacturing in a non-technical context, is becoming increasingly popular in the field of dentistry. As an essential step in the 3D printing process, postwashing with organic solvents can damage the printed resin polymer and possibly pose a risk to human health. The development of water-washable dental resins means that water can be used as a washing agent. However, the effects of washing agents and washing times on the mechanical and biocompatibility properties of water-washable resins remain unclear. This study investigated the impact of different washing agents (water, detergent, and alcohol) and washing time points (5, 10, 20, and 30 min) on the flexural strength, Vickers hardness, surface characterization, degree of conversion, biocompatibility, and monomer elution of 3D printed samples. Using water for long-term washing better preserved the mechanical properties, caused a smooth surface, and improved the degree of conversion, with 20 min of washing with water achieving the same biological performance as organic solvents. Water is an applicable agent option for washing the 3D printing water-washable temporary crown and bridge resin in the postwashing process. This advancement facilitates the development of other water-washable intraoral resins and the optimization of clinical standard washing guidelines.
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Affiliation(s)
- Yunqi Liu
- Department of Prosthodontics, College of Dentistry, Yonsei University, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Gan Jin
- Department of Prosthodontics, College of Dentistry, Yonsei University, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Jung-Hwa Lim
- Department of Prosthodontics, College of Dentistry, Yonsei University, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Jong-Eun Kim
- Department of Prosthodontics, College of Dentistry, Yonsei University, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea.
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Nam OH, Chung SY, Hyun HK, Ye JR, Jeong Y, Oh SE, Chae YK, Lee H. Influence of postprinting cleaning methods on the cleaning efficiency and surface and mechanical properties of three-dimensionally printed resins. J Prosthet Dent 2024:S0022-3913(24)00151-3. [PMID: 38582709 DOI: 10.1016/j.prosdent.2024.02.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 02/24/2024] [Accepted: 02/27/2024] [Indexed: 04/08/2024]
Abstract
STATEMENT OF PROBLEM The outcome of photopolymerized 3-dimensional (3D) printing is influenced by the methods used for postprinting cleaning, yet information on postprinting cleaning is sparse. PURPOSE The purpose of this in vitro study was to assess the cleaning efficiency and surface and mechanical properties of 3D printed resin according to postprinting cleaning methods. MATERIAL AND METHODS Specimens were fabricated from a 3D model using resin materials (NextDent C&B MFH and DIOnavi-P. MAX) and were tested for postprinting cleaning methods for 5 minutes with isopropyl alcohol, isopropyl alcohol + ultrasonic, ethyl alcohol, ethyl alcohol + ultrasonic, and ultrasonic alone. Postpolymerization was followed for 5 minutes. The cleaning efficiency, microcomputed tomography (µCT), surface roughness, Vickers hardness, and flexural strength of the specimens were evaluated. The 1-way ANOVA test was performed after considering normality. A post hoc analysis with Bonferroni was also performed (α=.008 or.005). RESULTS Ultrasonic in addition to cleaning solutions significantly improved the cleaning efficiency in NextDent C&B MFH specimens (P<.005), whereas ultrasonic did not affect the efficiency in DIOnavi-P. MAX specimens. No significant differences were found in surface roughness by postprinting cleaning methods in either NextDent C&B MFH or DIOnavi-P. MAX (P>.005). No significant changes in surface hardness were observed by postprinting cleaning methods (P>.008). In the NextDent C&B MFH, ethyl alcohol + ultrasonic significantly decreased the flexural strength (P<.005). There were no significant differences in the flexural strength in the DIOnavi-P. MAX (P>.005). CONCLUSIONS Ethyl alcohol was comparable with isopropyl alcohol for use as a postprinting cleaning solution for both NextDent C&B MFH and DIOnavi-P. MAX. The addition of ultrasonic to cleaning solutions should be applied with caution. These findings suggest that different postprinting cleaning methods can be recommended depending on the 3D printed resin materials.
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Affiliation(s)
- Ok Hyung Nam
- Associate Professor, Department of Pediatric Dentistry, Kyung Hee University, College of Dentistry, Kyung Hee University Medical Center, Seoul, Republic of Korea; and Associate Professor, Department of Pediatric Dentistry, School of Dentistry, Kyung Hee University, Seoul, Republic of Korea
| | - Sang-Yeop Chung
- Associate Professor, Department of Civil and Environmental Engineering, Yonsei University, Seoul, Republic of Korea
| | - Hong-Keun Hyun
- Professor, Department of Pediatric Dentistry, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Ju Ri Ye
- Department of Dentistry, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Yuwon Jeong
- PhD student, Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - Seo-Eun Oh
- PhD student, Department of Civil and Environmental Engineering, Yonsei University, Seoul, Republic of Korea
| | - Yong Kwon Chae
- Clinical Assistant Professor, Department of Pediatric Dentistry, Kyung Hee University, College of Dentistry, Kyung Hee University Medical Center, Seoul, Republic of Korea
| | - Hyeonjong Lee
- Associate Professor, Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
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Simeon P, Unkovskiy A, Saadat Sarmadi B, Nicic R, Koch PJ, Beuer F, Schmidt F. Wear resistance and flexural properties of low force SLA- and DLP-printed splint materials in different printing orientations: An in vitro study. J Mech Behav Biomed Mater 2024; 152:106458. [PMID: 38364445 DOI: 10.1016/j.jmbbm.2024.106458] [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: 12/21/2023] [Revised: 01/29/2024] [Accepted: 02/05/2024] [Indexed: 02/18/2024]
Abstract
OBJECTIVES To investigate the influence of material and printing orientation on wear resistance and flexural properties of one low force SLA- and two DLP-printed splint materials and to compare these 3D-printed splints to a subtractively manufactured splint material. METHODS Two DLP-printed (V-Print splint, LuxaPrint Ortho Plus) and one low force SLA-printed (Dental LT Clear) material, where specimens were printed in three printing orientations (0°, 45°, 90°), were investigated. In addition, one milled splint material (Zirlux Splint Transparent) was examined. A total of 160 specimens were produced for both test series. The two-body wear test was performed in a chewing simulator (80'000 cycles at 50 N with 5-55 °C thermocycling). Steatite balls were used as antagonists. The wear pattern was analyzed with a 3D digital microscope in terms of maximum vertical intrusion depth (mm) and total volume loss (mm³). The flexural properties were investigated by three-point bending in accordance with ISO 20795-1: 2013 (denture base polymers). The flexural strength (MPa) and the flexural modulus (MPa) were measured. Two-way ANOVA was performed to investigate the effects of the two independent variables material and printing orientation for the three 3D-printed materials. The comparison of the printing orientations within one material was carried out with one-way ANOVA with post-hoc Tukey tests. RESULTS Two-way ANOVA revealed that wear and flexural properties are highly dependent on the 3D-printed material (p < 0.001). Across groups, a significant effect was observed for wear depth (p = 0.031) and wear volume (p = 0.044) with regard to printing orientation but this was not found for flexural strength (p = 0.080) and flexural modulus (p = 0.136). One-way ANOVA showed that both DLP-printed groups showed no significant differences within the printing orientations in terms of wear and flexural properties. Dental LT Clear showed that 90° oriented specimens had higher flexural strength than 0° oriented ones (p < 0.001) and 45° oriented specimens also showed higher values than 0° ones (p = 0.038). No significant differences were observed within the printing orientations for flexural modulus and wear behaviour within this group. T-tests showed that the milled splints exhibited statistically higher wear resistance and flexural properties compared to all three 3D-printed splint materials (p < 0.001) and that highly significant differences were found between the 3D-printed splint materials for both test series. CONCLUSION Within the limitations of this in vitro study, it can be stated that wear behaviour and flexural properties are highly dependent on the 3D-printed material itself. Currently, milled splints exhibit higher wear resistance and flexural properties compared to 3D-printed splint materials. The printing orientation has a minor influence on the properties investigated. Nevertheless, two-way ANOVA also showed a significant influence of printing orientation in the wear test across groups and one-way ANOVA detected significant effects for SLA material in terms of flexural strength, with printing in 90° showing the highest flexural strength. Therefore, anisotropy was found in SLA material, but it can be limited with the employed printing parameters. Both DLP-printed materials showed no significant difference within the printing orientation.
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Affiliation(s)
- Philipp Simeon
- Charité - Universitätsmedizin Berlin, Center for Oral Health Sciences CC3, Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Aßmannshauser Str. 4-6, 14197, Berlin, Germany
| | - Alexey Unkovskiy
- Charité - Universitätsmedizin Berlin, Center for Oral Health Sciences CC3, Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Aßmannshauser Str. 4-6, 14197, Berlin, Germany; Department of Dental Surgery, Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya Street, 19с1, Moscow, 119146, Russia
| | - Bardia Saadat Sarmadi
- Charité - Universitätsmedizin Berlin, Center for Oral Health Sciences CC3, Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Aßmannshauser Str. 4-6, 14197, Berlin, Germany
| | - Robert Nicic
- Charité - Universitätsmedizin Berlin, Center for Oral Health Sciences CC3, Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Aßmannshauser Str. 4-6, 14197, Berlin, Germany
| | - Petra Julia Koch
- Charité - Universitätsmedizin Berlin, Center for Oral Health Sciences CC3, Department of Orthodontics and Orthofacial Orthopedics, Aßmannshauser Str. 4-6, 14197, Berlin, Germany
| | - Florian Beuer
- Charité - Universitätsmedizin Berlin, Center for Oral Health Sciences CC3, Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Aßmannshauser Str. 4-6, 14197, Berlin, Germany
| | - Franziska Schmidt
- Charité - Universitätsmedizin Berlin, Center for Oral Health Sciences CC3, Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Aßmannshauser Str. 4-6, 14197, Berlin, Germany.
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Luo K, Liu Q, Alhotan A, Dai J, Li A, Xu S, Li P. Effect of post-curing conditions on surface characteristics, physico-mechanical properties, and cytotoxicity of a 3D-printed denture base polymer. Dent Mater 2024; 40:500-507. [PMID: 38184445 DOI: 10.1016/j.dental.2023.12.017] [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: 02/21/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 01/08/2024]
Abstract
OBJECTIVE This study aims to investigate the influence of post-polymerization (post-curing) conditions on surface characteristics, flexural properties, water sorption and solubility, and cytotoxicity of additively manufactured denture base materials. METHODS The tested specimens were additively manufactured using digital light processing and classified into different post-curing condition groups: submerged in water (WAT), submerged in glycerin (GLY), and air exposure (AIR). An uncured specimen (UNC) was used as a control. The surface topography and roughness were observed. The flexural strength and modulus were determined via a three-point bending test. The water sorption and solubility were subsequently tested. Finally, an extract test was performed to assess cytotoxicity. RESULTS Different post-curing conditions had no significant effects on the surface topography and roughness (Sa value). Various post-curing conditions also had no significant effects on the flexural strength. Notably, the flexural modulus of the WAT group (2671.80 ± 139.42 MPa) was significantly higher than the AIR group (2197.47 ± 197.93 MPa, p = 0.0103). After different post-curing conditions, the water sorption and solubility of the specimens met the ISO standards. Finally, all post-curing conditions effectively reduced cytotoxic effects. SIGNIFICANCES Post-curing with different oxygen levels improved flexural properties, and flexural modulus significantly increased after the specimens were submerged in water. In addition, water sorption and solubility, and cytocompatibility were optimized by post-curing, irrespective of the post-curing conditions. Therefore, the water-submerged conditions optimized the flexural modulus of the 3D-printed denture base materials.
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Affiliation(s)
- Ke Luo
- Center of Oral Implantology, Stomatological Hospital, School of Stomatology, Southern Medical University, South Jiangnan Road No. 366, Guangzhou 510280, China
| | - Qian Liu
- Center of Oral Implantology, Stomatological Hospital, School of Stomatology, Southern Medical University, South Jiangnan Road No. 366, Guangzhou 510280, China
| | - Abdulaziz Alhotan
- Dental Health Department, College of Applied Medical Sciences, King Saud University, P.O.Box 10219, Riyadh 12372, Saudi Arabia
| | - Jingtao Dai
- Department of Orthodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, South Jiangnan Road No. 366, Guangzhou 510280, China
| | - An Li
- Department of Periodontology, Stomatological Hospital, School of Stomatology, Southern Medical University, South Jiangnan Road No. 366, Guangzhou 510280, China
| | - Shulan Xu
- Center of Oral Implantology, Stomatological Hospital, School of Stomatology, Southern Medical University, South Jiangnan Road No. 366, Guangzhou 510280, China.
| | - Ping Li
- School and Hospital of Stomatology, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Guangzhou Medical University, Guangzhou, Guangdong 510182, China; Department of Prosthodontics, School and Hospital of Stomatology, Guangzhou Medical University, Guangzhou, Guangdong 510182, China.
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Wulff J, Rauch A, Schmidt MB, Rosentritt M. Biaxial Flexural Strength of Printed Splint Materials. MATERIALS (BASEL, SWITZERLAND) 2024; 17:1112. [PMID: 38473585 PMCID: PMC10934272 DOI: 10.3390/ma17051112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/14/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024]
Abstract
One therapeutical alternative in the treatment of functional disorders is the use of printed oral splints. The mechanical properties of these materials are highly essential to their clinical effectiveness, and their performance may vary depending on factors such as cleaning, post-polymerization, or their orientation during construction. The objective of this in vitro investigation is to evaluate the effectiveness of the selected materials in terms of their biaxial flexural strength in relation to the criteria listed above. Splint materials were used in the printing of 720 discs. The printing process was carried out in different orientations in relation to the building platform. Either an automatic or manual cleaning process was performed on the samples. For post-polymerization, either an LED or Xenon light was utilized. A piston-on-three-ball test was used to measure the biaxial flexural strength (BFS) of the materials after they were stored in water for either 24 h or 60 days. The homogeneity of the data was controlled by employing the Levene method, and the differences between the groups were analyzed using the ANOVA and Bonferroni methods. After being stored for twenty-four hours, the mean BFS ranged anywhere from 79 MPa to 157 MPa. Following a period of sixty hours, the BFS exhibited a substantial drop and revealed values that ranged from 72 to 127 MPa. There was no significant difference that could be identified between the materials or between the various cleaning processes. The results of post-polymerization showed that the LED light produced higher means than the Xenon light did. In terms of position, the mean values varied greatly, with 0°'s mean value being 101 MPa, 45°'s mean value being 102 MPa, and 90°'s mean value being 115 MPa. The use of a build orientation of 90° and post-polymerization with LED light resulted in significantly increased biaxial flexural strength. According to this study, this design should be implemented in order to ensure that splint materials have the highest possible strength.
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Affiliation(s)
| | | | | | - Martin Rosentritt
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042 Regensburg, Germany; (J.W.); (A.R.); (M.B.S.)
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Caussin E, Moussally C, Le Goff S, Fasham T, Troizier-Cheyne M, Tapie L, Dursun E, Attal JP, François P. Vat Photopolymerization 3D Printing in Dentistry: A Comprehensive Review of Actual Popular Technologies. MATERIALS (BASEL, SWITZERLAND) 2024; 17:950. [PMID: 38399200 PMCID: PMC10890271 DOI: 10.3390/ma17040950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 02/09/2024] [Accepted: 02/13/2024] [Indexed: 02/25/2024]
Abstract
In this comprehensive review, the current state of the art and recent advances in 3D printing in dentistry are explored. This article provides an overview of the fundamental principles of 3D printing with a focus on vat photopolymerization (VP), the most commonly used technological principle in dental practice, which includes SLA, DLP, and LCD (or mSLA) technologies. The advantages, disadvantages, and shortcomings of these technologies are also discussed. This article delves into the key stages of the dental 3D printing process, from computer-aided design (CAD) to postprocessing, emphasizing the importance of postrinsing and postcuring to ensure the biocompatibility of custom-made medical devices. Legal considerations and regulatory obligations related to the production of custom medical devices through 3D printing are also addressed. This article serves as a valuable resource for dental practitioners, researchers, and health care professionals interested in applying this innovative technology in clinical practice.
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Affiliation(s)
- Elisa Caussin
- Faculty of Dental Surgery, University of Paris Cité, 75006 Paris, France
- Bretonneau Hospital, Assistance Publique des Hôpitaux de Paris (AP-HP), 75018 Paris, France
- Université of Paris Cité, URB2i, 92100 Montrouge, France
| | | | - Stéphane Le Goff
- Faculty of Dental Surgery, University of Paris Cité, 75006 Paris, France
- Université of Paris Cité, URB2i, 92100 Montrouge, France
| | - Timothy Fasham
- Faculty of Dental Surgery, University of Paris Cité, 75006 Paris, France
- Bretonneau Hospital, Assistance Publique des Hôpitaux de Paris (AP-HP), 75018 Paris, France
- Université of Paris Cité, URB2i, 92100 Montrouge, France
| | - Max Troizier-Cheyne
- Faculty of Dental Surgery, University of Paris Cité, 75006 Paris, France
- Bretonneau Hospital, Assistance Publique des Hôpitaux de Paris (AP-HP), 75018 Paris, France
- Université of Paris Cité, URB2i, 92100 Montrouge, France
| | - Laurent Tapie
- Faculty of Dental Surgery, University of Paris Cité, 75006 Paris, France
- Université of Paris Cité, URB2i, 92100 Montrouge, France
- EPF École d’Ingénieurs, 94230 Cachan, France
| | - Elisabeth Dursun
- Faculty of Dental Surgery, University of Paris Cité, 75006 Paris, France
- Université of Paris Cité, URB2i, 92100 Montrouge, France
- Henri Mondor Hospital, AP-HP, 94000 Créteil, France
| | - Jean-Pierre Attal
- Faculty of Dental Surgery, University of Paris Cité, 75006 Paris, France
- Université of Paris Cité, URB2i, 92100 Montrouge, France
- Charles Foix Hospital, AP-HP, 94200 Ivry-Sur-Seine, France
| | - Philippe François
- Faculty of Dental Surgery, University of Paris Cité, 75006 Paris, France
- Bretonneau Hospital, Assistance Publique des Hôpitaux de Paris (AP-HP), 75018 Paris, France
- Université of Paris Cité, URB2i, 92100 Montrouge, France
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11
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Cao J, Liu X, Cameron A, Aarts J, Choi JJE. Influence of different post-processing methods on the dimensional accuracy of 3D-printed photopolymers for dental crown applications - A systematic review. J Mech Behav Biomed Mater 2024; 150:106314. [PMID: 38113824 DOI: 10.1016/j.jmbbm.2023.106314] [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: 10/15/2023] [Revised: 12/05/2023] [Accepted: 12/07/2023] [Indexed: 12/21/2023]
Abstract
OBJECTIVES To perform a systematic review that provides an overview of the current literature on the influence of different post-processing methods on the accuracy of additive-manufactured (3D-printed) photopolymer crown materials, and whether more research is needed. MATERIALS AND METHODS The search used three online databases, Ovid (MEDLINE), Scopus and Web of Science which were screen for publications that involved assessing dimensional accuracy in post-processing of 3D printed dental crown materials. Publications that were literature reviews, abstracts, written in a language different from English, or publications that did not assess dimensional accuracy were excluded. RESULTS The included articles were published between 1995 and 2023. After the removal of duplicates using Endnote, 135 studies remained for further screening, 13 were selected for full-text analysis, and 7 studies were included in the systematic review. A total of 7 articles were examined and categorised based on several factors, such as the type of material, number of specimens per group, print layer thickness, print angle of specimens, 3D printer used, properties of the specimens studied, and the method of analysing the accuracy of the specimens. CONCLUSION It was found that post-processing washing times outside the prescribed instruction for use (IFU) may have an impact on the physical and biocompatibility characteristics of the material. Studies focusing on inert mediums during post-processing require more detailed investigation. The use of different post-curing conditions does not significantly affect the materials dimensional accuracy.
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Affiliation(s)
- Jason Cao
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand
| | - Xiaoyun Liu
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand
| | - Andrew Cameron
- School of Medicine and Dentistry, Griffith University, Australia; Member Centre of Biomedical and Rehabilitation Engineering, Menzies Health Institute Queensland, Australia
| | - John Aarts
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand
| | - Joanne Jung Eun Choi
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand.
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12
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Li P, Fernandez PK, Spintzyk S, Schmidt F, Yassine J, Beuer F, Unkovskiy A. Effects of layer thickness and build angle on the microbial adhesion of denture base polymers manufactured by digital light processing. J Prosthodont Res 2023; 67:562-567. [PMID: 36804247 DOI: 10.2186/jpr.jpr_d_22_00126] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
PURPOSE To investigate the effects of printing-layer thickness and build angle on the surface characteristics and microbial adhesion of denture base polymers manufactured by digital light processing (DLP). METHODS Specimens were additively manufactured using DLP. The specimens were printed with different printing-layer thicknesses (25, 50, and 100 μm) and build angles (0°, 45°, and 90°). Scanning electron microscopy was used to observe the surface topography, and the arithmetical mean heights (Sa) were measured. Moreover, the initial Candida albicans (C. albicans) adhesion to the specimens was evaluated using an adhesion test. Finally, two-way ANOVA and Tukey's multiple comparison tests were conducted. RESULTS The results regarding the Sa values exhibited a statistically significant interaction (F (4, 45) = 90.77, P < 0.0001). The build angle has a significant impact on the surface topography. Furthermore, quantitative results revealed that the printing-layer thickness significantly affected C. albicans adhesion (F (2, 99) = 6.96, P = 0.0015). CONCLUSIONS The surface roughness was significantly affected by the printing-layer thickness and the build angle. Additionally, the surface topography was mainly determined by the build angle. Furthermore, the adhesion of C. albicans to the DLP-printed denture surfaces was significantly affected by the printing-layer thickness but not by the build angle. Consequently, it is critical to decrease the thickness of the printing layer to produce digital dentures with optimal material properties.
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Affiliation(s)
- Ping Li
- Center of Oral Implantology, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
- Section Medical Materials Science and Technology, Tübingen University Hospital, Tübingen, Germany
| | - Pablo Kraemer Fernandez
- Department of Prosthodontics at the Centre of Dentistry, Oral Medicine and Maxillofacial Surgery with Dental School, Tübingen University Hospital, Tübingen, Germany
| | - Sebastian Spintzyk
- Section Medical Materials Science and Technology, Tübingen University Hospital, Tübingen, Germany
- ADMiRE Lab - Additive Manufacturing, intelligent Robotics, Sensors and Engineering, School of Engineering and IT, Carinthia University of Applied Sciences, Villach, Austria
| | - Franziska Schmidt
- Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jamila Yassine
- Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Florian Beuer
- Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Alexey Unkovskiy
- Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Dental Surgery, Sechenov First Moscow State Medical University, Moscow, Russia
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13
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Yan J, Cao L, Luo T, Qin D, Hua F, He H. In vitro evaluation of a novel fluoride-coated clear aligner with antibacterial and enamel remineralization abilities. Clin Oral Investig 2023; 27:6027-6042. [PMID: 37620439 DOI: 10.1007/s00784-023-05216-7] [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: 09/27/2022] [Accepted: 08/14/2023] [Indexed: 08/26/2023]
Abstract
OBJECTIVE To investigate the antibacterial and enamel remineralization performances as well as physicochemical properties and biocompatibility of a fluoride-coated clear aligner plastic (FCAP). MATERIALS AND METHODS FCAP and normal clear aligner plastic (CAP) was bought from the manufacturer (Angelalign Technology Inc, China). The FCAP was observed under scanning electron microscopy. Its element composition, resistance to separation, contact angle, and protein adhesion performance were characterized. Colony-forming unit (CFU) count and 3-(4,5)-dimethylthiazol(-z-y1)-3,5-diphenyltetrazolium bromide (MTT) assay were used to evaluate the antibacterial ability of Streptococcus mutans. Fluoride release-recharge patterns were obtained. Apatite formation was evaluated after immersing FCAP in artificial saliva. Enamel remineralization capability was evaluated in the demineralization model (immersing samples in demineralization solution for 36 h) and pH cycling model (immersing samples in demineralization solution and remineralization solution in turns for 14 days). Cell Counting Kit-8 (CCK-8) and live/dead cell staining kits were used for cytotoxicity assay. RESULTS The FCAP showed uniformly distributed fluoride and did not compromise protein adhesion performance. CFU count (5.47 ± 0.55 for CAP, 3.63 ± 0.38 for FCAP) and MTT assay (0.41 ± 0.025 for CAP, 0.28 ± 0.038) indicated that the FCAP had stronger antibacterial activity compared with normal CAP (P < 0.05 for both evaluations). The FCAP could release fluoride continuously for 14 days and could be recharged after immersing in NaF solution. The FCAP could induce the formation of hydroxyapatite in artificial saliva and could reduce the microhardness decrease, color change, and mineral loss of enamels in both two models (P < 0.05 for all evaluations). CCK-8 and live/dead cell staining analyses showed that the coating did not compromise the biocompatibility of the clear aligner (P > 0.05 for CCK-8 evaluation). CONCLUSIONS The FCAP had antibacterial, fluoride recharge, and enamel remineralization abilities while it did not compromise physicochemical properties and biocompatibility. CLINICAL RELEVANCE The FCAP has the potential to prevent enamel demineralization during clear aligner treatment.
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Affiliation(s)
- Jiarong Yan
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, China
- Department of Orthodontics, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Lingyun Cao
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, China
- Department of Orthodontics, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Ting Luo
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, China
- Department of Orthodontics, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Danchen Qin
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, China
- Department of Orthodontics, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Fang Hua
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
- Center for Orthodontics and Pediatric Dentistry at Optics Valley Branch, School & Hospital of Stomatology , Wuhan University, Wuhan, China.
- Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
| | - Hong He
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
- Department of Orthodontics, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
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14
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Rengarajan V, Clyde A, Pontsler J, Valiente J, Peel A, Huang Y. Assessing Leachable Cytotoxicity of 3D-Printed Polymers and Facile Detoxification Methods. 3D PRINTING AND ADDITIVE MANUFACTURING 2023; 10:1110-1121. [PMID: 37873063 PMCID: PMC10593418 DOI: 10.1089/3dp.2021.0216] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Additive manufacturing of polymers is gaining momentum in health care industries by providing rapid 3D printing of customizable designs. Yet, little is explored about the cytotoxicity of leachable toxins that the 3D printing process introduced into the final product. We studied three printable materials, which have various mechanical properties and are widely used in stereolithography 3D printing. We evaluated the cytotoxicity of these materials through exposing two fibroblast cell lines (human and mouse derived) to the 3D-printed parts, using overlay indirect contact assays. All the 3D-printed parts were measured toxic to the cells in a leachable manner, with flexible materials more toxic than rigid materials. Furthermore, we attempted to reduce the toxicity of the 3D-printed material by employing three treatment methods (further curing, passivation coating, and Soxhlet solvent extraction). The Soxhlet solvent extraction method was the most effective in removing the leachable toxins, resulting in the eradication of the material's toxicity. Passivation coating and further curing showed moderate and little detoxification, respectively. Additionally, mechanical testing of the materials treated with extraction methods revealed no significant impacts on its mechanical performances. As leachable toxins are broadly present in 3D-printed polymers, our cytotoxicity evaluation and reduction methods could aid in extending the selections of biocompatible materials and pave the way for the translational use of 3D printing.
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Affiliation(s)
| | - Angela Clyde
- Department of Biological Engineering, Utah State University, Logan, Utah, USA
- Institute of Antiviral Research, Utah State University, Logan, Utah, USA
| | - Jefferson Pontsler
- Department of Biological Engineering, Utah State University, Logan, Utah, USA
| | - Jonathan Valiente
- Department of Biological Engineering, Utah State University, Logan, Utah, USA
| | - Adreann Peel
- Department of Biological Engineering, Utah State University, Logan, Utah, USA
| | - Yu Huang
- Department of Biological Engineering, Utah State University, Logan, Utah, USA
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15
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Taher BB, Rasheed TA. The Impact of Adding Chitosan Nanoparticles on Biofilm Formation, Cytotoxicity, and Certain Physical and Mechanical Aspects of Directly Printed Orthodontic Clear Aligners. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2649. [PMID: 37836290 PMCID: PMC10574519 DOI: 10.3390/nano13192649] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023]
Abstract
Aligner treatment is associated with bacterial colonization, leading to enamel demineralization. Chitosan nanoparticles have been demonstrated to have antibacterial properties. This in vitro study aims to determine the effect of adding chitosan nanoparticles to directly 3D-printed clear aligner resin with regard to antibiofilm activity, cytotoxicity, degree of conversion, accuracy, deflection force, and tensile strength. Different concentrations (2%, 3%, and 5% w/w) of chitosan nanoparticles were mixed with the clear resin, and the samples were then 3D printed. Additionally, the thermoforming technique for aligner manufacturing was utilized. The obtained specimens were evaluated for antibiofilm activity against Streptococcus mutans bacteria and cytotoxicity against L929 and 3T3 cell lines. Additionally, Fourier transform infrared spectroscopy via attenuated total reflection analysis was used to assess the degree of conversion. Geomagic Control X software was utilized to analyze the accuracy. In addition, the deflection force and tensile strength were evaluated. The results indicated a notable reduction in bacterial colonies when the resin was incorporated with 3 and 5% chitosan nanoparticles. No significant changes in the cytotoxicity or accuracy were detected. In conclusion, integrating biocompatible chitosan nanoparticles into the resin can add an antibiofilm element to an aligner without compromising the material's certain biological, mechanical, and physical qualities at specific concentrations.
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Affiliation(s)
- Botan Barzan Taher
- Department of Pedodontics, Orthodontics and Preventive Dentistry, College of Dentistry, University of Sulaimani, Sulaymaniyah 46001, Iraq;
| | - Tara Ali Rasheed
- Department of Pedodontics, Orthodontics and Preventive Dentistry, College of Dentistry, University of Sulaimani, Sulaymaniyah 46001, Iraq;
- College of Dentistry, American University of Iraq-Sulaimani, Sulaymaniyah 46001, Iraq
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16
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Zhang R, Tang R, Spintzyk S, Tian Y, Xiang Y, Xu Y, Hu T. Three-Dimensional Printed Tooth Model with Root Canal Ledge: A Novel Educational Tool for Endodontic Training. Dent J (Basel) 2023; 11:213. [PMID: 37754333 PMCID: PMC10527572 DOI: 10.3390/dj11090213] [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: 07/30/2023] [Revised: 08/29/2023] [Accepted: 09/08/2023] [Indexed: 09/28/2023] Open
Abstract
Ledge formation presents a significant challenge in endodontic treatment. Yet, there is still a lack of educational tooth models for hands-on practice. This study aimed to create and evaluate a tooth model for ledge management practice. A natural tooth with curved roots was collected for scientific use under ethics committee approval. Following initial root canal preparation, the tooth was scanned using micro-computed tomography (μCT) and 3D reconstructed. A K-file, created via computer-aided design (CAD), was partly inserted into the root canal wall of the 3D reconstructed tooth. By subtracting the K-file from the tooth, a tooth model with a root canal ledge was produced. The model was then 3D printed for a hands-on workshop. An eight-item Likert-scale questionnaire was administered to 20 postgraduate students and 10 endodontists to assess the model's quality and training effectiveness. In addition, the success rate of bypassing and correcting the root canal ledge was documented. The feedback from both the students and experts was positive, and the results of the Mann-Whitney U test indicated no statistically significant differences found between the two groups (p > 0.05). The success rate of the students and the experts was 85% and 100%, respectively. In future applications, this novel tooth model is expected to address the existing gap in endodontic education and provide benefits for dental practitioners.
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Affiliation(s)
- Rui Zhang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Renjie Tang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Sebastian Spintzyk
- ADMiRE Research Center—Additive Manufacturing, Intelligent Robotics, Sensors and Engineering, School of Engineering and IT, Carinthia University of Applied Sciences, Europastraße 4, 9524 Villach, Austria
| | - Yuting Tian
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Yong Xiang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Yichen Xu
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, Department of Oral Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Tao Hu
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
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17
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Oh R, Lim JH, Lee CG, Lee KW, Kim SY, Kim JE. Effects of washing solution temperature on the biocompatibility and mechanical properties of 3D-Printed dental resin material. J Mech Behav Biomed Mater 2023; 143:105906. [PMID: 37178635 DOI: 10.1016/j.jmbbm.2023.105906] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 05/07/2023] [Accepted: 05/08/2023] [Indexed: 05/15/2023]
Abstract
The use of digital manufacturing, particularly additive manufacturing using three-dimensional (3D) printing, is expanding in the field of dentistry. 3D-printed resin appliances must undergo an essential process, post-washing, to remove residual monomers; however, the effect of the washing solution temperature on the biocompatibility and mechanical properties remains unclear. Therefore, we processed 3D-printed resin samples under different post-washing temperatures (without temperature control (N/T), 30 °C, 40 °C, and 50 °C) for different durations (5, 10, 15, 30, and 60 min) and evaluated the degree of conversion rate, cell viability, flexural strength, and Vickers hardness. Increasing the washing solution temperature significantly improved the degree of conversion rate and cell viability. Conversely, increasing the solution temperature and time decreased the flexural strength and microhardness. This study confirmed that the washing temperature and time influence the mechanical and biological properties of the 3D-printed resin. Washing 3D-printed resin at 30 °C for 30 min was most efficient to maintain optimal biocompatibility and minimize changes of mechanical properties.
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Affiliation(s)
- Rojee Oh
- Dental Hospital, Veterans Health Service Medical Center, Seoul, 05368, Republic of Korea; Department of Prosthodontics, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Jung-Hwa Lim
- Department of Prosthodontics, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Chan-Gyu Lee
- Department of Prosthodontics, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea; Oral Science Research Center, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Keun-Woo Lee
- Dental Hospital, Veterans Health Service Medical Center, Seoul, 05368, Republic of Korea; Department of Prosthodontics, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Sung-Yong Kim
- Dental Hospital, Veterans Health Service Medical Center, Seoul, 05368, Republic of Korea.
| | - Jong-Eun Kim
- Department of Prosthodontics, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
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18
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Somogyi A, Végh D, Róth I, Hegedüs T, Schmidt P, Hermann P, Géczi Z. Therapy for Temporomandibular Disorders: 3D-Printed Splints from Planning to Evaluation. Dent J (Basel) 2023; 11:dj11050126. [PMID: 37232777 DOI: 10.3390/dj11050126] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/29/2023] [Accepted: 04/28/2023] [Indexed: 05/27/2023] Open
Abstract
INTRODUCTION This article describes the authors' digital workflow-based method for fabricating intraoral occlusal splints, from planning to the evaluation phase. MATERIALS AND METHODS In our protocol, first, we had a registration phase. This included taking digital impressions, determining the centric relation (CR) position with the deprogrammer Luci Jig, and using the digital facebow for measuring the individual values. The laboratory phase was next, which included planning and manufacturing with a 3D printer. The last phase was delivery, when we checked the stability of the splint and adjusted the occlusal part. RESULT The average cost is lower for a fully digital splint than for conventional methods. In terms of time, there was also a significant difference between the classic and digital routes. From a dental technical point of view, the execution was much more predictable. The printed material was very rigid and, therefore, fragile. Compared to the analog method, the retention was much weaker. CONCLUSION The presented method permits time-efficient laboratory production, and may also be performed chairside in a dental office. The technology is perfectly applicable to everyday life. In addition to its many beneficial properties, its negative properties must also be highlighted.
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Affiliation(s)
- Andrea Somogyi
- Department of Prosthodontics, Faculty of Dentistry, Semmelweis University, 1085 Budapest, Hungary
| | - Dániel Végh
- Department of Prosthodontics, Faculty of Dentistry, Semmelweis University, 1085 Budapest, Hungary
| | - Ivett Róth
- Department of Prosthodontics, Faculty of Dentistry, Semmelweis University, 1085 Budapest, Hungary
| | - Tamás Hegedüs
- Department of Prosthodontics, Faculty of Dentistry, Semmelweis University, 1085 Budapest, Hungary
| | - Péter Schmidt
- Department of Prosthodontics, Faculty of Dentistry, Semmelweis University, 1085 Budapest, Hungary
| | - Péter Hermann
- Department of Prosthodontics, Faculty of Dentistry, Semmelweis University, 1085 Budapest, Hungary
| | - Zoltán Géczi
- Department of Prosthodontics, Faculty of Dentistry, Semmelweis University, 1085 Budapest, Hungary
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Goracci C, Juloski J, D’Amico C, Balestra D, Volpe A, Juloski J, Vichi A. Clinically Relevant Properties of 3D Printable Materials for Intraoral Use in Orthodontics: A Critical Review of the Literature. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16062166. [PMID: 36984045 PMCID: PMC10058724 DOI: 10.3390/ma16062166] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 03/01/2023] [Accepted: 03/07/2023] [Indexed: 06/05/2023]
Abstract
The review aimed at analyzing the evidence available on 3D printable materials and techniques used for the fabrication of orthodontic appliances, focusing on materials properties that are clinically relevant. MEDLINE/PubMed, Scopus, and Cochrane Library databases were searched. Starting from an initial retrieval of 669 citations, 47 articles were finally included in the qualitative review. Several articles presented proof-of-concept clinical cases describing the digital workflow to manufacture a variety of appliances. Clinical studies other than these case reports are not available. The fabrication of aligners is the most investigated application of 3D printing in orthodontics, and, among materials, Dental LT Clear Resin (Formlabs) has been tested in several studies, although Tera Harz TC-85 (Graphy) is currently the only material specifically marketed for direct printing of aligners. Tests of the mechanical properties of aligners materials lacked homogeneity in the protocols, while biocompatibility tests failed to assess the influence of intraoral conditions on eluents release. The aesthetic properties of 3D-printed appliances are largely unexplored. The evidence on 3D-printed metallic appliances is also limited. The scientific evidence on 3D printable orthodontic materials and techniques should be strengthened by defining international standards for laboratory testing and by starting the necessary clinical trials.
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Affiliation(s)
- Cecilia Goracci
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy
| | - Jovana Juloski
- Department of Orthodontics, School of Dental Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | - Claudio D’Amico
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy
| | - Dario Balestra
- School of Dental Medicine, Alfonso X El Sabio University, 28691 Madrid, Spain
| | - Alessandra Volpe
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy
| | - Jelena Juloski
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy
- Clinic for Paediatric and Preventive Dentistry, School of Dental Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | - Alessandro Vichi
- Dental Academy, University of Portsmouth, Portsmouth PO1 2QG, UK
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Effect of Denture Disinfectants on the Mechanical Performance of 3D-Printed Denture Base Materials. Polymers (Basel) 2023; 15:polym15051175. [PMID: 36904416 PMCID: PMC10007094 DOI: 10.3390/polym15051175] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/16/2023] [Accepted: 02/23/2023] [Indexed: 03/03/2023] Open
Abstract
Denture care and maintenance are necessary for both denture longevity and underlying tissue health. However, the effects of disinfectants on the strength of 3D-printed denture base resins are unclear. Herein, distilled water (DW), effervescent tablet, and sodium hypochlorite (NaOCl) immersion solutions were used to investigate the flexural properties and hardness of two 3D-printed resins (NextDent and FormLabs) compared with a heat-polymerized resin. The flexural strength and elastic modulus were investigated using the three-point bending test and Vickers hardness test before (baseline) immersion and 180 days after immersion. The data were analyzed using ANOVA and Tukey's post hoc test (α = 0.05), and further verified by using electron microscopy and infrared spectroscopy. The flexural strength of all the materials decreased after solution immersion (p < 0.001). The effervescent tablet and NaOCl immersion reduced the flexural strength (p < 0.001), with the lowest values recorded with the NaOCl immersion. The elastic modulus did not significantly differ between the baseline and after the DW immersion (p > 0.05), but significantly decreased after the effervescent tablet and NaOCl immersion (p < 0.001). The hardness significantly decreased after immersion in all the solutions (p < 0.001). The immersion of the heat-polymerized and 3D-printed resins in the DW and disinfectant solutions decreased the flexural properties and hardness.
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Nam NE, Hwangbo NK, Jin G, Shim JS, Kim JE. Effects of heat-treatment methods on cytocompatibility and mechanical properties of dental products 3D-printed using photopolymerized resin. J Prosthodont Res 2023; 67:121-131. [PMID: 35570000 DOI: 10.2186/jpr.jpr_d_21_00345] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE The purpose of this study was to test heat-treatment methods for improving the cytocompatibility of dental 3D printable photopolymer resins. METHODS Nextdent C&B resin and a digital light processing 3D printer were used to print all specimens, which were divided into seven groups as follows: 1-month storage at controlled room temperature, 20 to 25 °C (RT), 24-hour storage at RT, 24-hour storage in RT water, 1-min immersion in 80 °C water, 1-min immersion in 100 °C water, 5-min immersion in 100 °C water, and autoclaving. Cell viability tests, cytotoxicity tests, and confocal laser scanning microscopy were performed to analyze the cytocompatibility of the 3D-printed resin. Fourier-transform infrared spectroscopy was performed after heat-treatment to determine the degree of conversion (DC). RESULTS Immersing printed resin samples in 100 °C water for 1 or 5 min after the curing process was an effective method for increasing cytocompatibility by inducing the preleaching of toxic substances such as unpolymerized monomers, photoinitiators, and additives. Moreover, the DC can be increased by additional polymerization without affecting the mechanical properties of the material. CONCLUSIONS Immersing the printed photosensitive dental resins in 100 °C water for 5 min is a suitable method for increasing cytocompatibility and the DC.
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Affiliation(s)
- Na-Eun Nam
- BK21 FOUR Project, Department of Prosthodontics, Yonsei University College of Dentistry, Korea
| | - Na-Kyung Hwangbo
- Department of Orofacial Pain and Oral Medicine, Yonsei University College of Dentistry, Korea
| | - Gan Jin
- Department of Prosthodontics, College of Dentistry, Yonsei University, Korea
| | - June-Sung Shim
- Department of Prosthodontics, College of Dentistry, Yonsei University, Korea
| | - Jong-Eun Kim
- Department of Prosthodontics, College of Dentistry, Yonsei University, Korea
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22
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Jeršovaitė J, Šarachovaitė U, Matulaitienė I, Niaura G, Baltriukienė D, Malinauskas M. Biocompatibility enhancement via post-processing of microporous scaffolds made by optical 3D printer. Front Bioeng Biotechnol 2023; 11:1167753. [PMID: 37122855 PMCID: PMC10130666 DOI: 10.3389/fbioe.2023.1167753] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 03/30/2023] [Indexed: 05/02/2023] Open
Abstract
Providing a 3D environment that mimics the native extracellular matrix is becoming increasingly important for various applications such as cell function studies, regenerative medicine, and drug discovery. Among the most critical parameters to consider are the scaffold's complicated micro-scale geometry and material properties. Therefore, stereolithography based on photopolymerization is an emerging technique because of its ability to selectively form volumetric structures from liquid resin through localized polymerization reactions. However, one of the most important parameters of the scaffold is biocompatibility, which depends not only on the material but also on the exposure conditions and post-processing, which is currently underestimated. To investigate this systematically, microporous scaffolds with pore sizes of 0.05 mm3 corresponding to a porosity of 16,4% were fabricated using the stereolithography printer Asiga PICO2 39 UV from the widely used resins FormLabs Clear and Flexible. The use of various polymers is usually limited for cells because, after wet chemical development, the non-negligible amount of remaining monomers intertwined in the photopolymerized structures is significantly toxic to cells. Therefore, the aim of this research was to find the best method to remove monomers from the 3D scaffold by additional UV exposure. For this purpose, a Soxhlet extractor was used for the first time, and the monomers were immersed in different alcohols. A Raman microspectroscopy was also used to investigate whether different post-processing methods affect DC (cross-linking) to find out if this specifically affects the biocompatibility of the scaffolds. Finally, mesenchymal stem cells from rat dental pulp were examined to confirm the increased biocompatibility of the scaffolds and their ability to support cell differentiation into bone tissue cells.
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Affiliation(s)
- Jurga Jeršovaitė
- Laser Research Center, Faculty of Physics, Vilnius University, Vilnius, Lithuania
| | - Ugnė Šarachovaitė
- Institute of Biochemistry, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Ieva Matulaitienė
- Department of Organic Chemistry, Center for Physical Sciences and Technology, Vilnius, Lithuania
| | - Gediminas Niaura
- Department of Organic Chemistry, Center for Physical Sciences and Technology, Vilnius, Lithuania
| | - Daiva Baltriukienė
- Institute of Biochemistry, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Mangirdas Malinauskas
- Laser Research Center, Faculty of Physics, Vilnius University, Vilnius, Lithuania
- *Correspondence: Mangirdas Malinauskas,
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23
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Post-processing of DLP-printed denture base polymer: Impact of a protective coating on the surface characteristics, flexural properties, cytotoxicity, and microbial adhesion. Dent Mater 2022; 38:2062-2072. [DOI: 10.1016/j.dental.2022.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 10/26/2022] [Accepted: 11/11/2022] [Indexed: 11/27/2022]
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Influence of postwashing process on the elution of residual monomers, degree of conversion, and mechanical properties of a 3D printed crown and bridge materials. Dent Mater 2022; 38:1812-1825. [PMID: 36192277 DOI: 10.1016/j.dental.2022.09.017] [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: 01/12/2022] [Revised: 09/21/2022] [Accepted: 09/23/2022] [Indexed: 11/23/2022]
Abstract
OBJECTIVES This study aimed to determine the effects of the postwashing method and time on the mechanical properties and biocompatibility of three-dimensional (3D) printed crown and bridge resin. METHODS DLP (digital light processing)-printed specimens produced from Nextdent crown & bridge (C&B) resins were washed separately using an ultrasonic bath and rotary washer with TPM (tripropylene glycol monomethyl ether) for 3 min, 6 min, 10 min, 20 min, and 1 h. Postcuring was applied for 30 min to each specimen after the washing process. The flexural strength, Vickers hardness, water sorption and solubility, degree of conversion (DC), elution of residual monomers, and biocompatibility of the specimens were evaluated. RESULTS The ultrasonic bath showed greater washing efficacy by reducing the residual HEMA (2-hydroxyethyl methacrylate) from 2.0634 ppm to 0.1456 ppm and reducing the residual TEGDMA (triethylene glycol dimethacrylate) from 1.4862 ppm to 0.1484 ppm. With prolonged washing, the flexural strength significantly decreased from 129.67 ± 6.66 MPa (mean±standard deviation) to 103.17 ± 7.20 MPa, while the Vickers hardness increased slightly for the first 6 min and then decreased thereafter significantly. The DC was 87.78 ± 1.34% after 3 min and then gradually decreased with extended washing time. The cytotoxicity significantly decreases with the increment of the washing time. SIGNIFICANCE The washing effect on the elution of residual monomers was better for an ultrasonic bath than for a rotary washer. Extending the washing time reduces the mechanical properties and cytotoxicity of the Nextdent C&B resin.
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Xu Y, Huang H, Wu M, Tian Y, Wan Q, Shi B, Hu T, Spintzyk S. Rapid Additive Manufacturing of a Superlight Obturator for Large Oronasal Fistula in Pediatric Patient. Laryngoscope 2022; 133:1507-1512. [PMID: 36098478 DOI: 10.1002/lary.30352] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 07/13/2022] [Accepted: 08/02/2022] [Indexed: 11/08/2022]
Abstract
This study developed a novel digital workflow to fabricate a 3D printed hollow obturator for the prosthetic reconstruction of palatal fistula. It will provide cleft surgeons and therapists a choice for treating children with large palatal fistula before the appropriate age for surgical reconstruction. Laryngoscope, 2022.
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Affiliation(s)
- Yichen Xu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Oral Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Hanyao Huang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Min Wu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yuting Tian
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Qianbin Wan
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Oral Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Bing Shi
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Tao Hu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Sebastian Spintzyk
- ADMiRE Lab-Additive Manufacturing, Intelligent Robotics, Sensors and Engineering, School of Engineering and IT, Carinthia University of Applied Sciences, Villach, Austria
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26
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Lambart AL, Xepapadeas AB, Koos B, Li P, Spintzyk S. Rinsing postprocessing procedure of a 3D-printed orthodontic appliance material: Impact of alternative post-rinsing solutions on the roughness, flexural strength and cytotoxicity. Dent Mater 2022; 38:1344-1353. [PMID: 35752470 DOI: 10.1016/j.dental.2022.06.010] [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: 01/06/2022] [Revised: 05/04/2022] [Accepted: 06/05/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVE The present study evaluated the effect of different rinsing postprocessing solutions on surface characteristics, flexural strength, and cytotoxicity of an additive manufactured polymer for orthodontic appliances. These solutions have been deemed an alternative to the standard isopropanol which is a flammable liquid, known to have toxic effects. METHODS Tested specimens were manufactured using direct light processing of an orthodontic appliance polymer (FREEPRINT® splint 2.0, Detax) and post-processed with different post-rinsing solutions, including isopropanol (IPA), ethanol (EtOH), EASY 3D Cleaner (EYC), Yellow Magic7 (YM7), and RESINAWAY (RAY), respectively. All groups were post-cured following the manufacturer's instructions. Surface topography and roughness (Ra and Rv) were evaluated. In addition, flexural strength was measured by a three-point bending test. An extract test was performed to evaluate cytotoxicity. The data were analyzed by the Kruskal-Wallis test with Dunn's multiple comparisons test (p < 0.05). RESULTS Various post-rinsing solutions did not significantly affect the roughness values (Ra and Rv). Specimens post-processed with EtOH (98.1 ± 12.4 MPa) and EYC (101.1 ± 6.3 MPa) exhibited significantly lower flexural strength compared to the groups of IPA (110.7 ± 5.3 MPa), RAY (112.1 ± 5.6 MPa) and YM7 (117.3 ± 5.9 MPa), respectively. Finally, there were no cytotoxic effects of parts cleaned with different post-rinsing solutions. SIGNIFICANCE Considering the use of 3D-printed orthodontic appliance materials, different rinsing postprocessing procedures did not affect surface characteristics. However, the flexural strength was significantly influenced, which could be attributed to the chemical ingredients of the post-rinsing solutions. Various post-rinsing treatments had no alternation concerning cytocompatibility.
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Affiliation(s)
- Anna-Lena Lambart
- Department of Orthodontics, University Hospital Tübingen, Osianderstrasse 2-8, Tübingen 72076, Germany; Medical Materials Science and Technology, University Hospital Tübingen, Osianderstrasse 2-8, Tübingen 72076, Germany
| | - Alexander B Xepapadeas
- Department of Orthodontics, University Hospital Tübingen, Osianderstrasse 2-8, Tübingen 72076, Germany
| | - Bernd Koos
- Department of Orthodontics, University Hospital Tübingen, Osianderstrasse 2-8, Tübingen 72076, Germany
| | - Ping Li
- Center of Oral Implantology, Stomatological Hospital, Southern Medical University, South Jiangnan Road No. 366, Guangzhou 510280, China; Medical Materials Science and Technology, University Hospital Tübingen, Osianderstrasse 2-8, Tübingen 72076, Germany.
| | - Sebastian Spintzyk
- Medical Materials Science and Technology, University Hospital Tübingen, Osianderstrasse 2-8, Tübingen 72076, Germany; ADMiRE Lab - Additive Manufacturing, intelligent Robotics, Sensors and Engineering, School of Engineering and IT, Carinthia University of Applied Sciences, Europastraße 4, 9524 Villach, Austria
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Tedla G, Jarabek AM, Byrley P, Boyes W, Rogers K. Human exposure to metals in consumer-focused fused filament fabrication (FFF)/ 3D printing processes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 814:152622. [PMID: 34963600 PMCID: PMC8961686 DOI: 10.1016/j.scitotenv.2021.152622] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/16/2021] [Accepted: 12/19/2021] [Indexed: 05/31/2023]
Abstract
Fused filament fabrication (FFF) or 3D printing is a growing technology used in industry, cottage industry and for consumer applications. Low-cost 3D printing devices have become increasingly popular among children and teens. Consequently, 3D printers are increasingly common in households, schools, and libraries. Because the operation of 3D printers is associated with the release of inhalable particles and volatile organic compounds (VOCs), there are concerns of possible health implications, particularly for use in schools and residential environments that may not have adequate ventilation such as classrooms bedrooms and garages, etc. Along with the growing consumer market for low-cost printers and printer pens, there is also an expanding market for a range of specialty filaments with additives such as inorganic colorants, metal particles and nanomaterials as well as metal-containing flame retardants, antioxidants, heat stabilizers and catalysts. Inhalation of particulate-associated metals may represent a health risk depending on both the metal and internal dose to the respiratory tract. Little has been reported, however, about the presence, speciation, and source of metals in the emissions; or likewise the effect of metals on emission processes and toxicological implications of these 3D printer generated emissions. This report evaluates various issues including the following: metals in feedstock with a focus on filament characteristics and function of metals; the effect of metals on the emissions and metals detected in emissions; printer emissions, particle formation, transport, and transformation; exposure and translation to internal dose; and potential toxicity on inhaled dose. Finally, data gaps and potential areas of future research are discussed within these contexts.
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Affiliation(s)
- Getachew Tedla
- Watershed and Ecosystem Characterization Division, Center for Environmental Measurement and Modeling, USEPA, RTP, NC 27711, United States of America
| | - Annie M Jarabek
- Health and Environmental Effects Assessment Division, Center for Public Health and Environmental Assessment, USEPA, RTP, NC 27711, United States of America
| | - Peter Byrley
- Health and Environmental Effects Assessment Division, Center for Public Health and Environmental Assessment, USEPA, RTP, NC 27711, United States of America
| | - William Boyes
- Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, USEPA, RTP, NC 27711, United States of America
| | - Kim Rogers
- Watershed and Ecosystem Characterization Division, Center for Environmental Measurement and Modeling, USEPA, RTP, NC 27711, United States of America.
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Hegedus T, Kreuter P, Kismarczi-Antalffy AA, Demeter T, Banyai D, Vegh A, Geczi Z, Hermann P, Payer M, Zsembery A, Al-Hassiny A, Mukaddam K, Herber V, Jakse N, Vegh D. User Experience and Sustainability of 3D Printing in Dentistry. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19041921. [PMID: 35206116 PMCID: PMC8872260 DOI: 10.3390/ijerph19041921] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 01/30/2022] [Accepted: 02/03/2022] [Indexed: 02/04/2023]
Abstract
BACKGROUND 3D printing is a rapidly developing technology in the healthcare industry and in dentistry. Its application clearly shows that this area of digital dentistry has potential for everyday usage across all fields, including prosthodontics, orthodontics, maxillofacial surgery, and oral implantology. However, despite gaining ground, there is a lack of information about how specialists (dentists and dental technicians) use additive technology. Our research group aimed to investigate the impact of social media on additive manufacturing technology among dental specialists and their everyday usage of 3D printing. METHODS This paper investigated specialists' everyday usage of 3D printers via an online survey (Google Forms). The survey questions aimed to discover the number of 3D printers used, the accessibility of the devices, the annual cost, and the design programs. Since specialists tend to build online communities on social media, we circulated our study questionnaire using our profiles on LinkedIn, Facebook, and Instagram platforms during our research. RESULTS A total of 120 responses were received from 20 countries, with the most significant numbers being from Hungary 23.7% (n = 27), the United States 18.4% (n = 21), and the United Kingdom 7.9% (n = 9). Most of the participants were dentists (n = 68) or dental technicians (n = 29), but some CAD/CAM specialists (n = 23) also completed our survey. The participants had an average of 3.8 years (±0.7) of experience in the 3D printing field, and owned a total of 405 printing devices (3.6 on average/person). CONCLUSIONS The impact of social media on this research field is growing increasingly. Hence, we support specialists in joining virtual communities on professional platforms. This article intended to provide a practical overview, feedback, and direction for dentists interested in 3D printing technology. From our survey, we can conclude that additive technology is broadening dental applications and the services that we can provide for our patients.
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Affiliation(s)
- Tamas Hegedus
- Department of Prosthodontics, Semmelweis University, Szentkiralyi utca 47., 1088 Budapest, Hungary; (T.H.); (Z.G.); (P.H.)
| | - Patrik Kreuter
- Faculty of Dentistry, Semmelweis University, Szentkiralyi utca 47., 1088 Budapest, Hungary; (P.K.); (A.A.K.-A.)
| | | | - Tamas Demeter
- Department of General Dental Preclinical Practice, Semmelweis University, Szentkiralyi utca 47., 1088 Budapest, Hungary;
| | - Dorottya Banyai
- Department of Pediatric Dentistry and Orthodontics, Semmelweis University, Szentkiralyi utca 47., 1088 Budapest, Hungary;
| | - Adam Vegh
- Department of Maxillofacial Surgery and Dentistry, Semmelweis University, Maria utca 52., 1088 Budapest, Hungary;
| | - Zoltan Geczi
- Department of Prosthodontics, Semmelweis University, Szentkiralyi utca 47., 1088 Budapest, Hungary; (T.H.); (Z.G.); (P.H.)
| | - Peter Hermann
- Department of Prosthodontics, Semmelweis University, Szentkiralyi utca 47., 1088 Budapest, Hungary; (T.H.); (Z.G.); (P.H.)
| | - Michael Payer
- Division of Oral Surgery and Orthodontics, Department of Dental Medicine and Oral Health, School of Dentistry, Medical University Graz, Billrothgasse 4, 8010 Graz, Austria; (M.P.); (V.H.); (N.J.)
| | - Akos Zsembery
- Department of Oral Biology, Semmelweis University, Nagyvárad tér 4., 1089 Budapest, Hungary;
| | - Ahmad Al-Hassiny
- Institute of Digital Dentistry, 9 Hillary Court, Lower Hutt, Wellington 5010, New Zealand;
| | - Khaled Mukaddam
- Department of Oral Surgery, University Center for Dental Medicine Basel (UZB), University of Basel, Mattenstrasse 40, 4058 Basel, Switzerland;
| | - Valentin Herber
- Division of Oral Surgery and Orthodontics, Department of Dental Medicine and Oral Health, School of Dentistry, Medical University Graz, Billrothgasse 4, 8010 Graz, Austria; (M.P.); (V.H.); (N.J.)
| | - Norbert Jakse
- Division of Oral Surgery and Orthodontics, Department of Dental Medicine and Oral Health, School of Dentistry, Medical University Graz, Billrothgasse 4, 8010 Graz, Austria; (M.P.); (V.H.); (N.J.)
| | - Daniel Vegh
- Department of Prosthodontics, Semmelweis University, Szentkiralyi utca 47., 1088 Budapest, Hungary; (T.H.); (Z.G.); (P.H.)
- Division of Oral Surgery and Orthodontics, Department of Dental Medicine and Oral Health, School of Dentistry, Medical University Graz, Billrothgasse 4, 8010 Graz, Austria; (M.P.); (V.H.); (N.J.)
- Correspondence: ; Tel.: +36-30-7405164
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Francisco I, Paula AB, Ribeiro M, Marques F, Travassos R, Nunes C, Pereira F, Marto CM, Carrilho E, Vale F. The Biological Effects of 3D Resins Used in Orthodontics: A Systematic Review. Bioengineering (Basel) 2022; 9:bioengineering9010015. [PMID: 35049724 PMCID: PMC8773237 DOI: 10.3390/bioengineering9010015] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/27/2021] [Accepted: 12/30/2021] [Indexed: 11/16/2022] Open
Abstract
Three-dimensional (3D) resin medical-dental devices have been increasingly used in recent years after the emergence of digital technologies. In Orthodontics, therapies with aligners have gained popularity, mainly due to the aggressive promotion policies developed by the industry. However, their systemic effects are largely unknown, with few studies evaluating the systemic toxicity of these materials. The release of bisphenol A and other residual monomers have cytotoxic, genotoxic, and estrogenic effects. This systematic review aims to analyze the release of toxic substances from 3D resins used in Orthodontics and their toxic systemic effects systematically. The PICO question asked was, "Does the use of 3D resins in orthodontic devices induce cytotoxic effects or changes in estrogen levels?". The search was carried out in several databases and according to PRISMA guidelines. In vitro, in vivo, and clinical studies were included. The in vitro studies' risk of bias was assessed using the guidelines for the reporting of pre-clinical studies on dental materials by Faggion Jr. For the in vivo studies, the SYRCLE risk of bias tool was used, and for the clinical studies, the Cochrane tool. A total of 400 articles retrieved from the databases were initially scrutinized. Fourteen articles were included for qualitative analysis. The risk of bias was considered medium to high. Cytotoxic effects or estrogen levels cannot be confirmed based on the limited preliminary evidence given by in vitro studies. Evidence of the release of bisphenol A and other monomers from 3D resin devices, either in vitro or clinical studies, remains ambiguous. The few robust results in the current literature demonstrate the absolute need for further studies, especially given the possible implications for the young patient's fertility, which constitutes one of the largest groups of patients using these orthodontic devices.
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Affiliation(s)
- Inês Francisco
- Faculty of Medicine, Institute of Orthodontics, University of Coimbra, 3004-531 Coimbra, Portugal; (A.B.P.); (M.R.); (F.M.); (R.T.); (C.N.); (F.P.); (F.V.)
- Correspondence:
| | - Anabela Baptista Paula
- Faculty of Medicine, Institute of Orthodontics, University of Coimbra, 3004-531 Coimbra, Portugal; (A.B.P.); (M.R.); (F.M.); (R.T.); (C.N.); (F.P.); (F.V.)
- Faculty of Medicine, Institute of Integrated Clinical Practice, University of Coimbra, 3004-531 Coimbra, Portugal; (C.M.M.); (E.C.)
- Faculty of Medicine, Area of Environment Genetics and Oncobiology (CIMAGO), Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3004-531 Coimbra, Portugal
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3004-531 Coimbra, Portugal
| | - Madalena Ribeiro
- Faculty of Medicine, Institute of Orthodontics, University of Coimbra, 3004-531 Coimbra, Portugal; (A.B.P.); (M.R.); (F.M.); (R.T.); (C.N.); (F.P.); (F.V.)
| | - Filipa Marques
- Faculty of Medicine, Institute of Orthodontics, University of Coimbra, 3004-531 Coimbra, Portugal; (A.B.P.); (M.R.); (F.M.); (R.T.); (C.N.); (F.P.); (F.V.)
| | - Raquel Travassos
- Faculty of Medicine, Institute of Orthodontics, University of Coimbra, 3004-531 Coimbra, Portugal; (A.B.P.); (M.R.); (F.M.); (R.T.); (C.N.); (F.P.); (F.V.)
| | - Catarina Nunes
- Faculty of Medicine, Institute of Orthodontics, University of Coimbra, 3004-531 Coimbra, Portugal; (A.B.P.); (M.R.); (F.M.); (R.T.); (C.N.); (F.P.); (F.V.)
| | - Flávia Pereira
- Faculty of Medicine, Institute of Orthodontics, University of Coimbra, 3004-531 Coimbra, Portugal; (A.B.P.); (M.R.); (F.M.); (R.T.); (C.N.); (F.P.); (F.V.)
| | - Carlos Miguel Marto
- Faculty of Medicine, Institute of Integrated Clinical Practice, University of Coimbra, 3004-531 Coimbra, Portugal; (C.M.M.); (E.C.)
- Faculty of Medicine, Area of Environment Genetics and Oncobiology (CIMAGO), Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3004-531 Coimbra, Portugal
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3004-531 Coimbra, Portugal
- Faculty of Medicine, Institute of Experimental Pathology, University of Coimbra, 3004-531 Coimbra, Portugal
| | - Eunice Carrilho
- Faculty of Medicine, Institute of Integrated Clinical Practice, University of Coimbra, 3004-531 Coimbra, Portugal; (C.M.M.); (E.C.)
- Faculty of Medicine, Area of Environment Genetics and Oncobiology (CIMAGO), Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3004-531 Coimbra, Portugal
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-531 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3004-531 Coimbra, Portugal
| | - Francisco Vale
- Faculty of Medicine, Institute of Orthodontics, University of Coimbra, 3004-531 Coimbra, Portugal; (A.B.P.); (M.R.); (F.M.); (R.T.); (C.N.); (F.P.); (F.V.)
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Katheng A, Kanazawa M, Komagamine Y, Iwaki M, Namano S, Minakuchi S. Effect of post-rinsing time and method on accuracy of denture base manufactured with stereolithography. J Adv Prosthodont 2022; 14:45-55. [PMID: 35284051 PMCID: PMC8891682 DOI: 10.4047/jap.2022.14.1.45] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 02/12/2022] [Accepted: 02/15/2022] [Indexed: 11/08/2022] Open
Abstract
PURPOSE MATERIALS AND METHODS RESULTS CONCLUSION
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Affiliation(s)
- Awutsadaporn Katheng
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo, Tokyo, Japan
- Department of Restorative Dentistry, Faculty of Dentistry, Naresuan University, Phitsanulok, Thailand
| | - Manabu Kanazawa
- Department of Digital Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo, Tokyo, Japan
| | - Yuriko Komagamine
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo, Tokyo, Japan
| | - Maiko Iwaki
- Department of Oral Prosthetic Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo, Tokyo, Japan
| | - Sahaprom Namano
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo, Tokyo, Japan
| | - Shunsuke Minakuchi
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo, Tokyo, Japan
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31
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Effects of the Washing Time and Washing Solution on the Biocompatibility and Mechanical Properties of 3D Printed Dental Resin Materials. Polymers (Basel) 2021; 13:polym13244410. [PMID: 34960960 PMCID: PMC8705711 DOI: 10.3390/polym13244410] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/05/2021] [Accepted: 12/08/2021] [Indexed: 12/26/2022] Open
Abstract
Three-dimensional (3D) printing technology is highly regarded in the field of dentistry. Three-dimensional printed resin restorations must undergo a washing process to remove residual resin on the surface after they have been manufactured. However, the effect of the use of different washing solutions and washing times on the biocompatibility of the resulting resin restorations is unclear. Therefore, we prepared 3D-printed denture teeth and crown and bridge resin, and then washed them with two washing solutions (isopropyl alcohol and tripropylene glycol monomethyl ether) using different time points (3, 5, 10, 15, 30, 60, and 90 min). After this, the cell viability, cytotoxicity, and status of human gingival fibroblasts were evaluated using confocal laser scanning. We also analyzed the flexural strength, flexural modulus, and surface SEM imaging. Increasing the washing time increased the cell viability and decreased the cytotoxicity (p < 0.001). Confocal laser scanning showed distinct differences in the morphology and number of fibroblasts. Increasing the washing time did not significantly affect the flexural strength and surface, but the flexural modulus of the 90 min washing group was 1.01 ± 0.21 GPa (mean ± standard deviation), which was lower than that of all the other groups and decreased as the washing time increased. This study confirmed that the washing time affected the biocompatibility and mechanical properties of 3D printed dental resins.
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32
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Li P, Fernandez PK, Spintzyk S, Schmidt F, Beuer F, Unkovskiy A. Effect of additive manufacturing method and build angle on surface characteristics and Candida albicans adhesion to 3D printed denture base polymers. J Dent 2021; 116:103889. [PMID: 34800586 DOI: 10.1016/j.jdent.2021.103889] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/23/2021] [Accepted: 11/09/2021] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES To investigate the influence of additive manufacturing method and build angle on surface characteristics and Candida albicans (C. albicans) adhesion to 3D printed denture base polymers. METHODS Specimens of 3D printing denture base polymers were prepared by two printers, namely, stereolithography (SLA, Form 3B) and digital light processing technology (DLP, Solflex 350 plus). Three build angles were used: 0°, 45°, and 90°. Surface topography was examined by scanning electron microscopy. Also, arithmetical mean height (Sa) values were calculated. An adhesion test was performed to observe initial C. albicans adhesion to the specimens. The data were statistically analyzed using the two-way analysis of variance and Tukey's multiple comparison test. RESULTS The data of Sa values had statistically significant differences, which were mainly determined by the main factor of build angle (p < 0.05). Moreover, the quantitative results of C. albicans adhesion exhibited no significant differences: printing techniques (p = 0.7794) and build angle (p = 0.0589), respectively. CONCLUSIONS Surface roughness was significantly influenced by the build angle rather than by the AM method. Whereas, AM method (SLA and DLP) and build angle (0°, 45°, and 90º) had no impacts on the C. albicans adhesion to the 3D printed denture bases. CLINICAL SIGNIFICANCE Build angle dominates the surface roughness and topography of the 3D printed denture polymers. Our results indicate that C. albicans' adhesion might not be influenced by AM method and build angle.
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Affiliation(s)
- Ping Li
- Center of Oral Implantology, Stomatological Hospital, Southern Medical University, South Jiangnan Road No. 366, Guangzhou 510280, China; Section Medical Materials Science and Technology, Tübingen University Hospital, Osianderstr. 2-8, Tübingen 72076, Germany.
| | - Pablo Kraemer Fernandez
- Department of Prosthodontics at the Centre of Dentistry, Oral Medicine and Maxillofacial Surgery with Dental School, Tübingen University Hospital, Osianderstr. 2-8, Tübingen 72076, Germany
| | - Sebastian Spintzyk
- Section Medical Materials Science and Technology, Tübingen University Hospital, Osianderstr. 2-8, Tübingen 72076, Germany; ADMiRE Lab - Additive Manufacturing, intelligent Robotics, Sensors and Engineering, School of Engineering and IT, Carinthia University of Applied Sciences, Villach, Austria
| | - Franziska Schmidt
- Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Aßmannshauser Str. 4-6, Berlin 14197, Germany
| | - Florian Beuer
- Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Aßmannshauser Str. 4-6, Berlin 14197, Germany
| | - Alexey Unkovskiy
- Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Aßmannshauser Str. 4-6, Berlin 14197, Germany; Department of Dental Surgery, Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya Street, 19с1, Moscow 119146, Russia
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33
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Krechmer JE, Phillips B, Chaloux N, Shomberg R, Daube C, Manchanda G, Murray S, McCarthy A, Fonseca R, Thakkar J, Loose B, Herndon SC, Jayne JT, Worsnop DR, Canagaratna MR. Chemical Emissions from Cured and Uncured 3D-Printed Ventilator Patient Circuit Medical Parts. ACS OMEGA 2021; 6:30726-30733. [PMID: 34805700 PMCID: PMC8600644 DOI: 10.1021/acsomega.1c04695] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 10/22/2021] [Indexed: 05/27/2023]
Abstract
Medical shortages during the COVID-19 pandemic saw numerous efforts to 3D print personal protective equipment and treatment supplies. There is, however, little research on the potential biocompatibility of 3D-printed parts using typical polymeric resins as pertaining to volatile organic compounds (VOCs), which have specific relevance for respiratory circuit equipment. Here, we measured VOCs emitted from freshly printed stereolithography (SLA) replacement medical parts using proton transfer reaction mass spectrometry and infrared differential absorption spectroscopy, and particulates using a scanning mobility particle sizer. We observed emission factors for individual VOCs ranging from ∼0.001 to ∼10 ng cm-3 min-1. Emissions were heavily dependent on postprint curing and mildly dependent on the type of SLA resin. Curing reduced the emission of all observed chemicals, and no compounds exceeded the recommended dose of 360 μg/d. VOC emissions steadily decreased for all parts over time, with an average e-folding time scale (time to decrease to 1/e of the starting value) of 2.6 ± 0.9 h.
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Affiliation(s)
- Jordan E. Krechmer
- Aerodyne
Research, Inc., 45 Manning
Road, Billerica, Massachusetts 01821, United States
| | - Brennan Phillips
- Department
of Ocean Engineering, The University of
Rhode Island, 215 South
Ferry Road, Narragansett, Rhode Island 02882, United States
| | - Nicholas Chaloux
- Department
of Ocean Engineering, The University of
Rhode Island, 215 South
Ferry Road, Narragansett, Rhode Island 02882, United States
| | - Russell Shomberg
- Department
of Ocean Engineering, The University of
Rhode Island, 215 South
Ferry Road, Narragansett, Rhode Island 02882, United States
| | - Conner Daube
- Aerodyne
Research, Inc., 45 Manning
Road, Billerica, Massachusetts 01821, United States
| | - Gaurav Manchanda
- Formlabs,
Inc., 35 Medford Street, Somerville, Massachusetts 02143, United States
| | - Sam Murray
- Formlabs,
Inc., 35 Medford Street, Somerville, Massachusetts 02143, United States
| | - Alex McCarthy
- Formlabs,
Inc., 35 Medford Street, Somerville, Massachusetts 02143, United States
| | - Rodrigo Fonseca
- Computer
Science Department, Brown University, Providence, Rhode Island 02903, United States
| | - Jinen Thakkar
- Department
of Medicine, Brown University and Alpert
Medical School, Providence, Rhode Island 02903, United States
| | - Brice Loose
- Department
of Ocean Engineering, The University of
Rhode Island, 215 South
Ferry Road, Narragansett, Rhode Island 02882, United States
| | - Scott C. Herndon
- Aerodyne
Research, Inc., 45 Manning
Road, Billerica, Massachusetts 01821, United States
| | - John T. Jayne
- Aerodyne
Research, Inc., 45 Manning
Road, Billerica, Massachusetts 01821, United States
| | - Douglas R. Worsnop
- Aerodyne
Research, Inc., 45 Manning
Road, Billerica, Massachusetts 01821, United States
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34
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Postpolymerization of a 3D-printed denture base polymer: Impact of post-curing methods on surface characteristics, flexural strength, and cytotoxicity. J Dent 2021; 115:103856. [PMID: 34695506 DOI: 10.1016/j.jdent.2021.103856] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/30/2021] [Accepted: 10/20/2021] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE This study investigated the influence of postpolymerization of a three-dimensional (3D) printed denture base polymer. The effect of post-curing methods on surface characteristics, flexural strength, and cytotoxicity was evaluated. METHODS A total of 172 specimens were additively manufactured using one denture base material (V-Print dentbase, VOCO) and further post-cured by different light-curing devices, including Otoflash G171 (OF), Labolight DUO (LL), PCU LED (PCU), and LC-3DPrintbox (PB), respectively. Polymethyl methacrylate resin (PalaExpress Ultra) was used as a reference (REF). Afterward, surface topography was observed using scanning electron microscopy, and surface roughness was measured (n = 6). Furthermore, flexural strength was tested (n = 20). Cytotoxicity was evaluated by the extract and direct contact tests. The data were analyzed using the Kolmogorov-Smirnov test and one-way ANOVA followed by Tukey's multiple comparisons and Kruskal-Wallis tests (p < 0.05). RESULTS The different post-curing methods applied did not significantly influence surface topography and roughness (Ra). Meanwhile, specimens post-cured by PCU (162.3 ± 44.16 MPa) and PB (171.2 ± 34.41 MPa) showed significantly higher flexural strength than those post-cured by OF (131.3 ± 32.87 MPa) and REF (131.2 ± 19.19 MPa), respectively. Additionally, various post-curing methods effectively decreased the cytotoxic effects of 3D-printed denture base polymer. CONCLUSIONS Different post-curing methods did not significantly alter the Ra values of the 3D-printed denture base material. However, flexural strength was significantly affected by the postpolymerization methods, which might be attributed to the different wavelengths of post-curing devices. In addition, various postpolymerization methods reduced the cytotoxic effects of the 3D-printed denture base polymer. CLINICAL SIGNIFICANCE Flexural strength of additively manufactured denture bases depends on the postpolymerization strategy. Therefore, an appropriate post-curing method is required to optimize the flexural strength of 3D-printed denture materials.
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Aretxabaleta M, Unkovskiy A, Koos B, Spintzyk S, Xepapadeas AB. Accuracy Evaluation of Additively and Subtractively Fabricated Palatal Plate Orthodontic Appliances for Newborns and Infants-An In Vitro Study. MATERIALS (BASEL, SWITZERLAND) 2021; 14:4103. [PMID: 34361299 PMCID: PMC8347028 DOI: 10.3390/ma14154103] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 12/02/2022]
Abstract
Different approaches for digital workflows have already been presented for their use in palatal plates for newborns and infants. However, there is no evidence on the accuracy of CAD/CAM manufactured orthodontic appliances for this kind of application. This study evaluates trueness and precision provided by different CAM technologies and materials for these appliances. Samples of a standard palatal stimulation plate were manufactured using stereolithography (SLA), direct light processing (DLP) and subtractive manufacturing (SM). The effect of material (for SM) and layer thickness (for DLP) were also investigated. Specimens were digitized with a laboratory scanner (D2000, 3Shape) and analyzed with a 3D inspection software (Geomagic Control X, 3D systems). For quantitative analysis, differences between 3D datasets were measured using root mean square (RMS) error values for trueness and precision. For qualitative analysis, color maps were generated to detect locations of deviations within each sample. SM showed higher trueness and precision than AM technologies. Reducing layer thickness in DLP did not significantly increase accuracy, but prolonged manufacturing time. All materials and technologies met the clinically acceptable range and are appropriate for their use. DLP with 100 µm layer thickness showed the highest efficiency, obtaining high trueness and precision within the lowest manufacturing time.
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Affiliation(s)
- Maite Aretxabaleta
- Department of Orthodontics in the University Centre of Dentistry, Oral Medicine and Maxillofacial Surgery within the University Hospital Tübingen, Osianderstr. 2-8, 72076 Tübingen, Germany; (B.K.); (A.B.X.)
| | - Alexey Unkovskiy
- Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Aßmannshauser Str. 4-6, 14197 Berlin, Germany;
- Department of Dental Surgery, Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya Street, 19c1, 119146 Moscow, Russia
| | - Bernd Koos
- Department of Orthodontics in the University Centre of Dentistry, Oral Medicine and Maxillofacial Surgery within the University Hospital Tübingen, Osianderstr. 2-8, 72076 Tübingen, Germany; (B.K.); (A.B.X.)
| | - Sebastian Spintzyk
- Section Medical Materials Science and Technology, University Hospital Tübingen, Osianderstr. 2-8, 72076 Tübingen, Germany;
| | - Alexander B. Xepapadeas
- Department of Orthodontics in the University Centre of Dentistry, Oral Medicine and Maxillofacial Surgery within the University Hospital Tübingen, Osianderstr. 2-8, 72076 Tübingen, Germany; (B.K.); (A.B.X.)
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36
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Hassan R, Aslam Khan MU, Abdullah AM, Abd Razak SI. A Review on Current Trends of Polymers in Orthodontics: BPA-Free and Smart Materials. Polymers (Basel) 2021; 13:1409. [PMID: 33925332 PMCID: PMC8123702 DOI: 10.3390/polym13091409] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 12/12/2022] Open
Abstract
Polymeric materials have always established an edge over other classes of materials due to their potential applications in various fields of biomedical engineering. Orthodontics is an emerging field in which polymers have attracted the enormous attention of researchers. In particular, thermoplastic materials have a great future utility in orthodontics, both as aligners and as retainer appliances. In recent years, the use of polycarbonate brackets and base monomers bisphenol A glycerolate dimethacrylate (bis-GMA) has been associated with the potential release of bisphenol A (BPA) in the oral environment. BPA is a toxic compound that acts as an endocrine disruptor that can affect human health. Therefore, there is a continuous search for non-BPA materials with satisfactory mechanical properties and an esthetic appearance as an alternative to polycarbonate brackets and conventional bis-GMA compounds. This study aims to review the recent developments of BPA-free monomers in the application of resin dental composites and adhesives. The most promising polymeric smart materials are also discussed for their relevance to future orthodontic applications.
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Affiliation(s)
- Rozita Hassan
- Orthodontic Unit, School of Dental Sciences, Universiti Sains Malaysia, Kelantan 16150, Malaysia;
| | - Muhammad Umar Aslam Khan
- BioInspired Device and Tissue Engineering Research Group, School of Biomedical Engineering and Health Sciences, Faculty of Engineering, Universiti Teknologi Malaysia, Skudai 81300, Malaysia;
- Nanoscience and Technology Department (NS & TD), National Center for Physics, Islamabad 44000, Pakistan
- Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Abdul Manaf Abdullah
- Orthodontic Unit, School of Dental Sciences, Universiti Sains Malaysia, Kelantan 16150, Malaysia;
| | - Saiful Izwan Abd Razak
- BioInspired Device and Tissue Engineering Research Group, School of Biomedical Engineering and Health Sciences, Faculty of Engineering, Universiti Teknologi Malaysia, Skudai 81300, Malaysia;
- Center for Advanced Composite Materials, Universiti Teknologi Malaysia, Skudai 81300, Malaysia
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Stereolithography vs. Direct Light Processing for Rapid Manufacturing of Complete Denture Bases: An In Vitro Accuracy Analysis. J Clin Med 2021; 10:jcm10051070. [PMID: 33806627 PMCID: PMC7961584 DOI: 10.3390/jcm10051070] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 02/22/2021] [Accepted: 02/25/2021] [Indexed: 12/18/2022] Open
Abstract
The topical literature lacks any comparison between stereolithography (SLA) and direct light processing (DLP) printing methods with regard to the accuracy of complete denture base fabrication, thereby utilizing materials certified for this purpose. In order to investigate this aspect, 15 denture bases were printed with SLA and DLP methods using three build angles: 0°, 45° and 90°. The dentures were digitalized using a laboratory scanner (D2000, 3Shape) and analyzed in analyzing software (Geomagic Control X, 3D systems). Differences between 3D datasets were measured using the root mean square (RMS) value for trueness and precision and mean and maximum deviations were obtained for each denture base. The data were statistically analyzed using two-way ANOVA and Tukey’s multiple comparison test. A heat map was generated to display the locations of the deviations within the intaglio surface. The overall tendency indicated that SLA denture bases had significantly higher trueness for most build angles compared to DLP (p < 0.001). The 90° build angle may provide the best trueness for both SLA and DLP. With regard to precision, statistically significant differences were found in the build angles only. Higher precision was revealed in the DLP angle of 0° in comparison to the 45° and 90° angles.
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