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Zhang Y, Jin X, Savoldi F, Han J, Su RKL, Fok A, Chen J, Tsoi JKH. Validation of a double-semicircular notched configuration for mechanical testing of orthodontic thermoplastic aligner materials. J Mech Behav Biomed Mater 2024; 155:106543. [PMID: 38636445 DOI: 10.1016/j.jmbbm.2024.106543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 04/05/2024] [Accepted: 04/10/2024] [Indexed: 04/20/2024]
Abstract
The potential of using specimens with a double-semicircular-notched configuration for performing tensile tests of orthodontic thermoplastic aligner materials was explored. Unnotched and double-semicircular-notched specimens were loaded in tension using a universal testing machine to determine their tensile strength, while finite element analysis (FEA) and digital image correlation (DIC) were used to estimate stress and strain, respectively. The shape did affect the tensile strength, demonstrating the importance of unifying the form of the specimen. During the elastic phase under tension, double-semicircular-notched specimens showed similar behavior to unnotched specimens. However, great variance was observed in the strain patterns of the unnotched specimens, which exhibited greater chance of end-failure, while the strain patterns of the double-semicircular-notched specimens showed uniformity. Considerable agreement between the theoretical (FEA) and practical models (DIC) further confirmed the validity of the double-semicircular-notched models.
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Affiliation(s)
- Yuqing Zhang
- Fujian Key Laboratory of Oral Diseases, School and Hospital of Stomatology, Fujian Medical University, PR China; Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Xiaozhuang Jin
- Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Fabio Savoldi
- Orthodontics, Division of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Jianmin Han
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Ray Kai Leung Su
- Department of Civil Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong, China
| | - Alex Fok
- Division of Biomaterials, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, USA
| | - Jiang Chen
- Fujian Key Laboratory of Oral Diseases, School and Hospital of Stomatology, Fujian Medical University, PR China.
| | - James Kit-Hon Tsoi
- Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
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Nayak AS, H C KK. A comparative study on tensile strength of various thermoplastic polymers sheets following thermoforming on a pre-treatment and post-treatment maxillary model of a patient: an in vitro study. Clin Oral Investig 2024; 28:240. [PMID: 38570397 DOI: 10.1007/s00784-024-05640-3] [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: 09/29/2023] [Accepted: 03/30/2024] [Indexed: 04/05/2024]
Abstract
OBJECTIVES Thermoplastic polymers show alteration in their mechanical properties after thermoforming on a dental model. The purpose of this in-vitro study was to evaluate the tensile strength of different thermoplastic polymer sheets thermoformed on a pre-treatment (moderate crowding) and post-treatment (well-aligned) maxillary model of a patient. MATERIALS AND METHODS Forty maxillary models (Twenty Pre-treatment & twenty Post-treatment of uniform dimension) were made by duplicating them using alginate Hydrogum 5 (Zhermack). Samples were then divided into eight groups of 5 samples each. The thermoplastic sheets Imprelon® (Scheu-Dent), AVAC R® (Jaypee), Placa Crystal® (BioART), EZ-VAC® (3A Medes)-1.0 mm thick were thermoformed on these models respectively. The sample was retrieved using ceramic bur mounted on a straight hand-piece and subjected for testing using TINIUS Olsen 10ST micro universal testing machine and recorded. RESULTS There was no statistically significant difference (P > .05) in tensile strength of thermoformed thermoplastic polymer sheets between pre-treatment and post-treatment maxillary model. Tensile strength of EZ-VAC (3A Medes) showed higher variation between pre-treatment and post-treatment maxillary model though it was found to be statistically insignificant (P > .05). Significant difference (P < .05) was seen between groups when they were compared separately among pre-treatment and post-treatment models. CONCLUSION Placa Crystal (BioART) among the pre-treatment group, EZ - VAC (3A Medes) among the post-treatment group, showed highest tensile strength. CLINICAL RELEVANCE Results of the study highlights the necessity to test materials in conditions which stands in accordance with the clinical scenario to a considerable extent and also emphasizes the need for further study in aligner.
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Affiliation(s)
- Ashwath S Nayak
- Department of Orthodontics and Dentofacial Orthopedics, Bapuji Dental College and Hospital, Davangere, Karnataka, India, 577004.
| | - Kiran Kumar H C
- Department of Orthodontics and Dentofacial Orthopedics, Bapuji Dental College and Hospital, Davangere, Karnataka, India, 577004
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Jin C, Gray AR, Brunton PA, Farella M, Mei L. Effect of carbamide peroxide on biomechanical properties of vacuum-formed retainers: A split-mouth randomized controlled trial. J Dent 2024; 143:104902. [PMID: 38432352 DOI: 10.1016/j.jdent.2024.104902] [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: 11/19/2023] [Revised: 01/22/2024] [Accepted: 02/26/2024] [Indexed: 03/05/2024] Open
Abstract
OBJECTIVE To investigate the effect of tooth whitening on biomechanical properties of vacuum-formed retainers (VFRs). METHODS Using a split-mouth, randomised controlled trial design, thirty participants were randomly allocated to receive whitening on either the upper or the lower arch, using 10 % carbamide peroxide for two weeks. Biomechanical properties such as hardness, tensile strength, and surface roughness were assessed two weeks after whitening was completed. RESULTS Tensile strength of the whitening arch (mean ± SD: 40.93 ± 3.96 MPa) was significantly lower than that of the control (47.40 ± 5.03 MPa) (difference 6.47 MPa, 95 % CI 4.51 - 8.42, p < 0.001). Hardness and internal roughness of the whitening arch (VHN = 14.63 ± 2.29 N/mm2 and Ra = 1.33 ± 0.35 µm, respectively) were significantly greater than those of the control (12.22 ± 1.86 N/mm2 and 0.96 ± 0.29 µm, respectively) (differences 2.41 N/mm2, 95 % CI 1.56 - 3.25, p < 0.001 and 0.37 µm, 95 % CI 0.23 - 0.51, p < 0.001, respectively). The whitening arch showed greater tooth colour change (ΔE = 6.00 ± 3.32) than the control (ΔE = 2.50 ± 1.70) (difference = 3.50, 95 % CI 2.43 - 4.56, p < 0.001). CONCLUSIONS Based on this short-term study, marked tooth colour change was achieved by whitening with VFRs as the whitening trays, but this changed the VFRs' biomechanical properties, including a decrease in tensile strength and an increase in hardness and internal roughness. CLINICAL SIGNIFICANCE The application of carbamide peroxide in VFRs may compromise their mechanical properties.
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Affiliation(s)
- Carrol Jin
- Discipline of Orthodontics, Department of Oral Science, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin 9016, New Zealand
| | - Andrew R Gray
- University of Otago, Biostatistics Centre, Division of Health Sciences, 310 Great King Street, Dunedin 9016, New Zealand
| | | | - Mauro Farella
- Discipline of Orthodontics, Department of Oral Science, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, New Zealand; Department of Surgical Sciences, University of Cagliari, Italy
| | - Li Mei
- Discipline of Orthodontics, Department of Oral Science, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin 9016, New Zealand.
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Srinivasan B, Padmanabhan S, Srinivasan S. Comparative evaluation of physical and mechanical properties of clear aligners - a systematic review. Evid Based Dent 2024; 25:53. [PMID: 38017152 DOI: 10.1038/s41432-023-00937-w] [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: 06/21/2023] [Accepted: 09/25/2023] [Indexed: 11/30/2023]
Abstract
INTRODUCTION The clinical effectiveness of clear aligners depends on the material properties both physical and mechanical. The purpose of this systematic review is to evaluate the physical and mechanical properties of different clear aligner materials and changes in the same during and after intra-oral use. METHODS Search was done in five electronic databases: Pubmed, Embase, Scopus, Web of Science and Ovid individually by two reviewers. In vivo, Ex vivo and In vitro studies that evaluated the physical and mechanical properties of clear aligner materials were selected. The risk of bias assessment was performed using a modified Cochrane risk of bias tool. RESULTS From the 24 articles selected, 19 evaluated a single physical property and 23 articles evaluated a single mechanical property of clear aligner materials. All domains in the risk of bias assessment showed low risk of bias except for 'blinding of outcome' which was unclear in almost all the selected studies. Properties such as hardness, optical properties, stiffness, and yield strength were found to be different for different clear aligner materials and were found to change with thermoforming, with intra-oral aging, and in simulated intraoral conditions. Due to heterogenicity in the parameters used to assess physical or mechanical properties a meta-analysis could not be done. CONCLUSIONS Properties like hardness, color, stiffness, stress relaxation and creep behavior were different for various clear aligner materials and were found to deteriorate with thermoforming and intra-oral aging. Polyurethane-based materials have a higher level of hardness and stiffness but exhibit increased creep and stress relaxation properties. PROSPERO REGISTRATION NUMBER CRD42021269597.
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Affiliation(s)
- Bhadrinath Srinivasan
- Department of Orthodontics, Sri Ramchandra Institute of Higher Education and Research, PIN- 600116, Chennai, India
| | - Sridevi Padmanabhan
- Department of Orthodontics, Sri Ramchandra Institute of Higher Education and Research, PIN- 600116, Chennai, India.
| | - Sivakumar Srinivasan
- Department of Applied Mechanics, Indian Institute of Technology (Madras), 600036, Chennai, India
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Nicita F, D'Amico C, Filardi V, Spadaro D, Aquilio E, Mancini M, Fiorillo L. Chemical-Physical Characterization of PET-G-Based Material for Orthodontic Use: Preliminary Evaluation of micro-Raman Analysis. Eur J Dent 2024; 18:228-235. [PMID: 37247624 PMCID: PMC10959632 DOI: 10.1055/s-0043-1764424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
OBJECTIVES Orthodontic treatment with clear thermoplastic aligners is in great demand by patients especially for aesthetics. Any alterations in the chemical composition of the thermoplastic material for aligners, subjected to the oral environment and exposure to various commonly used substances, could influence the desired orthodontic movement decreasing the predictability of the treatment. The objective of this study was to determine the chemical-physical characterization by micro-Raman spectroscopy of a thermoplastic material based on polyethylene terephthalate glycol (PET-G) used for the manufacture of Lineo aligners (Micerium Lab, Avegno, Italy) subjected to different staining beverages and cleaning agents. MATERIALS AND METHODS Twenty-two thermoformed PET-G samples were immersed to various substances of daily use for 10 and 15 days (coffee, tea, Coca-Cola, red wine, colloidal silver disinfectant, nicotine, artificial saliva, cigarette smoke, and different combinations of saliva with some of the previous solutions). Subsequently, the chemical-physical characterization was investigated by micro-Raman spectroscopy. RESULTS The analysis of the spectra acquired for all the specimens showed no difference in the exposure to the different solvents at 10 and 15 days. Furthermore, having ascertained the heterogeneous surface morphology of the PET-G material due to thermoforming, various deposits were present on all the samples whose consistency and concentration depended on the substance used. CONCLUSION The spectroscopic investigations have provided a precise and detailed analysis of the qualitative and structural data of the PET-G material under examination. No significant structural modifications of the thermoplastic polymer were found after immersion in different solutions in the exposure times adopted.
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Affiliation(s)
- Fabiana Nicita
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, via Consolare Valeria, Messina, Italy
| | - Cesare D'Amico
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, via Consolare Valeria, Messina, Italy
| | - Vincenzo Filardi
- D.A. Research and Internationalization, University of Messina, Via Consolato del mare 41, Messina, Italy
| | | | | | - Maura Mancini
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, via Consolare Valeria, Messina, Italy
| | - Luca Fiorillo
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, via Consolare Valeria, Messina, Italy
- Multidisciplinary Department of Medical-Surgical and Dental Specialties, University of Campania Luigi Vanvitelli, Naples, Italy
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Ferati K, Bexheti-Ferati A, Palermo A, Pezzolla C, Trilli I, Sardano R, Latini G, Inchingolo AD, Inchingolo AM, Malcangi G, Inchingolo F, Dipalma G, Mancini A. Diagnosis and Orthodontic Treatment of Obstructive Sleep Apnea Syndrome Children-A Systematic Review. Diagnostics (Basel) 2024; 14:289. [PMID: 38337805 PMCID: PMC10855184 DOI: 10.3390/diagnostics14030289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/04/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
Obstructive sleep apnea syndrome (OSAS) is a respiratory illness that is associated with recurrent episodes of either partial or full obstruction of the upper airways, or apnea, among other sleep disorders. This study aims to analyze, through a literature review, whether orthodontic treatment can be a good treatment strategy for this type of disorder. We performed a database search on Scopus, Web of Science, and Pubmed with the keywords OSA(S) and orthodontics to select the papers under evaluation. The criteria for inclusion were articles related to OSA(S) children undergoing an orthodontic treatment and clinical studies or case series, excluding systematic reviews, narrative reviews, meta-analyses, adult studies, animal models, and in vitro studies. The screening phase ended with the selection of 16 publications for this work. RME, or rapid maxillary expansion, turned out to be the preferred orthodontic treatment in cases of pediatric OSAS. The goal of this orthodontic procedure is to increase the hard palate's transverse diameter by reopening the mid-palatal suture. Children with maxillary contraction and dental malocclusion typically undergo such a procedure and have excellent results. However, OSAS is a multifactorial disorder; it does not seem related to the morphology of the oral cavity, and therefore, it is not always possible to cope with this problem exclusively through orthodontic treatment.
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Affiliation(s)
- Kenan Ferati
- Faculty of Medicine, University of Tetovo, 1220 Tetovo, North Macedonia; (K.F.); (A.B.-F.)
| | | | - Andrea Palermo
- College of Medicine and Dentistry, Birmingham B4 6BN, UK;
| | - Carmen Pezzolla
- Interdisciplinary Department of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (C.P.); (I.T.); (R.S.); (G.L.); (A.D.I.); (A.M.I.); (G.D.); (A.M.)
| | - Irma Trilli
- Interdisciplinary Department of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (C.P.); (I.T.); (R.S.); (G.L.); (A.D.I.); (A.M.I.); (G.D.); (A.M.)
| | - Roberta Sardano
- Interdisciplinary Department of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (C.P.); (I.T.); (R.S.); (G.L.); (A.D.I.); (A.M.I.); (G.D.); (A.M.)
| | - Giulia Latini
- Interdisciplinary Department of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (C.P.); (I.T.); (R.S.); (G.L.); (A.D.I.); (A.M.I.); (G.D.); (A.M.)
| | - Alessio Danilo Inchingolo
- Interdisciplinary Department of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (C.P.); (I.T.); (R.S.); (G.L.); (A.D.I.); (A.M.I.); (G.D.); (A.M.)
| | - Angelo Michele Inchingolo
- Interdisciplinary Department of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (C.P.); (I.T.); (R.S.); (G.L.); (A.D.I.); (A.M.I.); (G.D.); (A.M.)
| | - Giuseppina Malcangi
- Interdisciplinary Department of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (C.P.); (I.T.); (R.S.); (G.L.); (A.D.I.); (A.M.I.); (G.D.); (A.M.)
| | - Francesco Inchingolo
- Interdisciplinary Department of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (C.P.); (I.T.); (R.S.); (G.L.); (A.D.I.); (A.M.I.); (G.D.); (A.M.)
| | - Gianna Dipalma
- Interdisciplinary Department of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (C.P.); (I.T.); (R.S.); (G.L.); (A.D.I.); (A.M.I.); (G.D.); (A.M.)
| | - Antonio Mancini
- Interdisciplinary Department of Medicine, University of Bari “Aldo Moro”, 70124 Bari, Italy; (C.P.); (I.T.); (R.S.); (G.L.); (A.D.I.); (A.M.I.); (G.D.); (A.M.)
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Aldweesh AH, Al-Maflehi NS, AlGhizzi M, AlShayea E, Albarakati SF. Comparison of mechanical properties and color stability of various vacuum-formed orthodontic retainers: An in vitro study. Saudi Dent J 2023; 35:953-959. [PMID: 38107045 PMCID: PMC10724479 DOI: 10.1016/j.sdentj.2023.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/30/2023] [Accepted: 09/04/2023] [Indexed: 12/19/2023] Open
Abstract
Vacuum-formed retainer (VFR) is the most used retainer due to its higher aesthetic properties and lower cost, their mechanical properties of are important in determining the stability and long-term use of appliances made out of them. AIM This study aimed to evaluate and compare the flexural modulus, surface hardness, and color stability of three different VFR materials. METHODS Three different VFR materials, namely Duran, Keystone, and Zendura, of 1 mm thickness, were tested after thermoforming for flexural modulus, hardness, and color stability. They were formed over a stainless-steel model of 12 mm diameter and 6 mm height. RESULTS There were significant statistical differences (p = 0.000) in the flexural modulus and hardness of the three materials. Regarding color stability, Zendura exhibited significantly higher ΔE* values than Keystone and Duran (p < 0.05). CONCLUSIONS Zendura had the highest flexural modulus and hardness compared with Duran and Keystone; however, it is more susceptible to color change compared to the other tested materials.
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Affiliation(s)
- Aljazi H. Aldweesh
- Division of Orthodontics, Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Nassr S. Al-Maflehi
- Periodontics and Community Dentistry, College of Dentistry, King Saud University, Saudi Arabia
| | | | - Eman AlShayea
- Division of Orthodontics, Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Sahar F. Albarakati
- Division of Orthodontics, Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
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Šimunović L, Jurela A, Sudarević K, Bačić I, Meštrović S. Differential Stability of One-layer and Three-layer Orthodontic Aligner Blends under Thermocycling: Implications for Clinical Durability. Acta Stomatol Croat 2023; 57:286-299. [PMID: 38283309 PMCID: PMC10812913 DOI: 10.15644/asc57/4/1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 12/01/2023] [Indexed: 01/30/2024] Open
Abstract
Objectives To optimize the therapeutic usefulness of aligners, it is crucial to understand how their mechanical properties alter with time. Materials and methods Specimens from four different brands, including Duran+, CA® Pro, Zendura A, and Zendura FLX, were produced for material testing of thermoplastic orthodontic aligners (TOA) using dimensions measuring 4mm x 10mm. Each brand's 24 samples were split into three groups as follows: G1 being thermoformed, G2 being thermoformed and underwent 500 thermocycles (simulating 7 days), and G3 being thermoformed and underwent 1000 thermocycles (simulating 14 days). Surface roughness, modulus of elasticity in bending, and spectrophotometry were used to assess the effect of aging on TOAs. Results After 1000 thermocycles, Duran+ had the highest modulus of elasticity and differed statistically from all other groups. The intragroup comparison showed that only Duran+'s elastic modulus significantly changed after 1000 thermocycles in comparison with the control group. Surface roughness values (Ra), did not statistically differ among brands or thermocycling group measures. The change in chemical properties was not significant in any brand. Conclusion One-layer PETG (Duran+) failed to demonstrate stability after in vitro aging, thus suggesting that clinicians should be aware of the change in mechanical properties when using one-layer PETG (Duran +) in a 2 weeks regime.
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Affiliation(s)
- Luka Šimunović
- Department of Orthodontics, School of Dental Medicine, University of Zagreb, Gundulićeva 5, 10000 Zagreb, Croatia
| | | | | | - Ivana Bačić
- Forensic Science Centre "Ivan Vučetić", Ministry of the Interior, Ilica 351, 10000 Zagreb, Croatia
| | - Senka Meštrović
- Department of Orthodontics, School of Dental Medicine, University of Zagreb, Gundulićeva 5, 10000 Zagreb, Croatia
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Chen SM, Huang TH, Ho CT, Kao CT. Force degradation study on aligner plates immersed in various solutions. J Dent Sci 2023; 18:1845-1849. [PMID: 37799905 PMCID: PMC10547977 DOI: 10.1016/j.jds.2023.06.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/18/2023] [Indexed: 10/07/2023] Open
Abstract
Background/purpose The strength of aligners themselves has a high decay rate and is susceptible to accelerated degradation in the environment. The purpose of this study was to compare three types of invisible aligner films after being immersed in coffee, tea, cola, and red wine for seven days and to evaluate the changes in their strengths. Materials and methods Three types of invisible aligner plates with a thickness of 0.75 mm, i.e., Duran T (polyethylene terephthalate glycol, PETG), Biolon (polyethylene terephthalate, PET), and Zendura FLX (polyurethane, PU), were soaked in artificial saliva and four drinks (coffee, tea, cola, red wine) for 1, 4, and 7 days. The strength test was performed by using the three-point bending test method. The residual strength ratio for the same type of invisible correction film at the same time was separately recorded. The independent t-test was used to indicate significant differences at P < 0.05. Results The Biolon invisible correction film soaked in cola, red wine and artificial saliva showed significant differences on the 1st and 4th days (P < 0.05). The Duran T invisible correction film soaked in coffee and artificial saliva showed significant differences on the first day (P < 0.05). The Zendura FLX invisible correction film had a waterproof layer on the surface, and there was no significant difference between soaking in any drink and soaking in saliva (P > 0.05). Conclusion Invisible correction films with different ingredients soaked in solutions show a strength decay phenomenon, except for those with TPU ingredients.
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Affiliation(s)
- Shou-Min Chen
- School of Dentistry, College of Oral Medicine, Chung Shan Medical University, Taichung, Taiwan
- Orthodontic Department, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Tsui-Hsein Huang
- School of Dentistry, College of Oral Medicine, Chung Shan Medical University, Taichung, Taiwan
- Dental Department, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Chun-Te Ho
- School of Dentistry, College of Oral Medicine, Chung Shan Medical University, Taichung, Taiwan
- Orthodontic Department, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Chia-Tze Kao
- Orthodontic Department, Chung Shan Medical University Hospital, Taichung, Taiwan
- Dental Department, Chung Shan Medical University Hospital, Taichung, Taiwan
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Šimunović L, Blagec T, Meštrović S. Resistance of PETG Materials on Thermocycling and Brushing. Dent J (Basel) 2023; 11:dj11050135. [PMID: 37232786 DOI: 10.3390/dj11050135] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 05/27/2023] Open
Abstract
The aim was to assess the impact of thermocycling and brushing on the surface roughness and mass of PETG material-the most commonly used for orthodontic retainers. A total of 96 specimens were exposed to thermocycling and brushing with three different kinds of toothbrushes depending on the number and thickness of the bristles. Surface roughness and mass were evaluated three times: initially, after thermocycling, and after brushing. In all four brands, both thermocycling and brushing increased surface roughness significantly (p < 0.001), with Biolon having the lowest and Track A having the highest. In terms of brushing, only Biolon samples showed statistically significant increased roughness after brushing with all three types of brushes, in comparison to Erkodur A1, where differences were not statistically significant. Thermocycling increased the mass of all samples, but a statistically significant difference was found only in Biolon (p = 0.0203), while after brushing, decreased mass was found in all specimens, statistically significant only in Essix C+ (CS 1560: p = 0.016). PETG material showed instability when exposed to external influences- thermocycling produced an increase in roughness and mass, and brushing mostly caused an increase in roughness and decrease in mass. Erkodur A1 demonstrated the greatest stability, whereas Biolon demonstrated the lowest.
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Affiliation(s)
- Luka Šimunović
- Department of Orthodontics, School of Dental Medicine Zagreb, University of Zagreb, 10000 Zagreb, Croatia
| | - Tadeja Blagec
- Department of Orthodontics, School of Dental Medicine Zagreb, University of Zagreb, 10000 Zagreb, Croatia
| | - Senka Meštrović
- Department of Orthodontics, School of Dental Medicine Zagreb, University of Zagreb, 10000 Zagreb, Croatia
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Porojan L, Toma FR, Bîrdeanu MI, Vasiliu RD, Matichescu A. Topographical and Optical Characteristics of Thermoplastic Dental Appliances Materials Related to Water Sorption. J Funct Biomater 2023; 14:jfb14040190. [PMID: 37103280 PMCID: PMC10146702 DOI: 10.3390/jfb14040190] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/22/2023] [Accepted: 03/27/2023] [Indexed: 03/31/2023] Open
Abstract
Clear thermoplastic materials have increased in popularity in the dental field due to their various applications, combination of excellent aesthetics, and good biomechanical behavior, but they may be influenced by different environmental conditions. The purpose of the present study was to assess the topographical and optical characteristics of thermoplastic dental appliances materials relative to water sorption. PET-G polyester thermoplastic materials were evaluated in this study. Related to water uptake and desiccation stages, surface roughness was analyzed, and three-dimensional AFM profiles were generated for nano-roughness measurements. Optical CIE L*a*b* coordinates were recorded and parameters like translucency (TP), contrast ratio for the opacity (CR), and opalescence (OP) were derived. Levels of color changes were achieved. Statistical analyses were performed. Water uptake significantly increases the specific weight of the materials, and after desiccation, the mass decreases. Roughness increased after water immersion as well. Regression coefficients indicated a positive correlation between TP and a* and between OP and b*. Studied PET-G materials have a different behavior to water exposure, but for all their specific weight, they increased significantly within the first 12 h. It is accompanied by an increase in the roughness values, even if they continue to be kept below the critical mean surface roughness. On nano-level, 3D images show an increase in inhomogeneity in the network structure of particles. Slight color changes were registered.
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Affiliation(s)
- Liliana Porojan
- Department of Dental Prostheses Technology (Dental Technology), Center for Advanced Technologies in Dental Prosthodontics, Faculty of Dental Medicine, Victor Babes University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
- Correspondence:
| | - Flavia Roxana Toma
- Department of Dental Prostheses Technology (Dental Technology), Center for Advanced Technologies in Dental Prosthodontics, Faculty of Dental Medicine, Victor Babes University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
| | - Mihaela Ionela Bîrdeanu
- National Institute for Research and Development in Electrochemistry and Condensed Matter, A. Păunescu Podeanu Str. No. 144, 300569 Timisoara, Romania
| | - Roxana Diana Vasiliu
- Department of Dental Prostheses Technology (Dental Technology), Center for Advanced Technologies in Dental Prosthodontics, Faculty of Dental Medicine, Victor Babes University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
| | - Anamaria Matichescu
- Department of Preventive, Community Dentistry and Oral Health, Center for Advanced Technologies in Dental Prosthodontics, Faculty of Dental Medicine, Victor Babes University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
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12
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Quinzi V, Orilisi G, Vitiello F, Notarstefano V, Marzo G, Orsini G. A spectroscopic study on orthodontic aligners: First evidence of secondary microplastic detachment after seven days of artificial saliva exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 866:161356. [PMID: 36603638 DOI: 10.1016/j.scitotenv.2022.161356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/20/2022] [Accepted: 12/30/2022] [Indexed: 06/17/2023]
Abstract
Clear orthodontic aligners have recently seen increasing popularity. The thermoplastic materials present several advantages, even if it is known that all plastic products can be subjected to environmental and mechanical degradation, leading to the release of microplastics (MPs). Their ingestion could cause oxidative stress and inflammatory lesions. This study aims to evaluate the potential detachment of MPs by clear aligners due to mechanical friction simulated with a 7-day protocol in artificial saliva. The study was performed on orthodontic clear aligners from different manufacturers: Alleo (AL); FlexiLigner (FL); F22 Aligner (F22); Invisalign® (INV); Lineo (LIN); Arc Angel (ARC), and Ortobel Aligner (OR). For each group, two aligners were immersed in artificial saliva for 7 days and stirred for 5 h/day, simulating the physiological teeth mechanical friction. After 7 days, the artificial saliva was filtered; then, filters were analyzed by Raman Microspectroscopy (RMS) and Scanning Electron Microscopy (SEM), respectively to chemically identify the polymeric matrix and to measure the number and size of the detected MPs. RMS spectra revealed that AL, FL, LIN, ARC, and OR aligners were composed by polyethylene terephthalate, while F22 and INV ones by polyurethane. SEM analysis showed that the highest number of MPs was found in ARC and the lowest in INV (p < 0.05). As regards MPs' size, no statistically significant difference was found among groups, with most MPs ranging from 5 to 20 μm. Noteworthy, a highly significant correlation (p < 0.0001) was highlighted between the distribution of MPs size and the different typologies of aligners. This in vitro study highlighted for the first time the detachment of MPs from clear aligners due to mechanical friction. This evidence may represent a great concern in the clinical practice since it could impact human general health.
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Affiliation(s)
- Vincenzo Quinzi
- Università degli Studi dell'Aquila, Dipartimento di Medicina Clinica, Sanità Pubblica, Scienze della Vita e dell'Ambiente, Piazza Salvatore Tommasi, 67100 L'Aquila, Italy
| | - Giulia Orilisi
- Università Politecnica delle Marche, Dipartimento di Scienze Cliniche Specialistiche ed Odontostomatologiche, Via Tronto 10, 60126 Ancona, Italy
| | - Flavia Vitiello
- Università Politecnica delle Marche, Dipartimento di Scienze Cliniche Specialistiche ed Odontostomatologiche, Via Tronto 10, 60126 Ancona, Italy
| | - Valentina Notarstefano
- Università Politecnica delle Marche, Dipartimento di Scienze della Vita e dell'Ambiente, Via Brecce Bianche, 60131 Ancona, Italy
| | - Giuseppe Marzo
- Università degli Studi dell'Aquila, Dipartimento di Medicina Clinica, Sanità Pubblica, Scienze della Vita e dell'Ambiente, Piazza Salvatore Tommasi, 67100 L'Aquila, Italy
| | - Giovanna Orsini
- Università Politecnica delle Marche, Dipartimento di Scienze Cliniche Specialistiche ed Odontostomatologiche, Via Tronto 10, 60126 Ancona, Italy.
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13
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Iosif C, Cuc S, Prodan D, Moldovan M, Petean I, Labunet A, Barbu Tudoran L, Badea IC, Man SC, Badea ME, Chifor R. Mechanical Properties of Orthodontic Cements and Their Behavior in Acidic Environments. MATERIALS (BASEL, SWITZERLAND) 2022; 15:7904. [PMID: 36431389 PMCID: PMC9697370 DOI: 10.3390/ma15227904] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/03/2022] [Accepted: 11/06/2022] [Indexed: 06/16/2023]
Abstract
The present research is focused on three different classes of orthodontic cements: resin composites (e.g., BracePaste); resin-modified glass ionomer RMGIC (e.g., Fuji Ortho) and resin cement (e.g., Transbond). Their mechanical properties such as compressive strength, diametral tensile strength and flexural strength were correlated with the samples' microstructures, liquid absorption, and solubility in liquid. The results show that the best compressive (100 MPa) and flexural strength (75 Mpa) was obtained by BracePaste and the best diametral tensile strength was obtained by Transbond (230 MPa). The lowestvalues were obtained by Fuji Ortho RMGIC. The elastic modulus is relatively high around 14 GPa for BracePaste, and Fuji Ortho and Transbond have only 7 GPa. The samples were also subjected to artificial saliva and tested in different acidic environments such as Coca-Cola and Red Bull. Their absorption and solubility were investigated at different times ranging from 1 day to 21 days. Fuji Ortho presents the highest liquid absorption followed by Transbond, the artificial saliva has the best absorption and Red Bull has the lowest absorption. The best resistance to the liquids was obtained by BracePaste in all environments. Coca-Cola presents values four times greater than the ones observed for artificial saliva. Solubility tests show that BracePaste is more soluble in artificial saliva, and Fuji Ortho and Transbond are more soluble in Red Bull and Coca-Cola. Scanning electron microscopy (SEM) images evidenced a compact structure for BracePaste in all environments sustaining the lower liquid absorption values. Fuji Ortho and Transbond present a fissure network allowing the liquid to carry out in-depth penetration of materials. SEM observations are in good agreement with the atomic force microscopy (AFM) results. The surface roughness decreases with the acidity increasing for BracePaste meanwhile it increases with the acidity for Fuji Ortho and Transbond. In conclusion: BracePaste is recommended for long-term orthodontic treatment for patients who regularly consume acidic beverages, Fuji Ortho is recommended for short-term orthodontic treatment for patients who regularly consume acidic beverages and Transbond is recommended for orthodontic treatment over an average time period for patients who do not regularly consume acidic beverages.
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Affiliation(s)
- Cristina Iosif
- Department of Prosthetic Dentistry and Dental Materials, “Iuliu Hatieganu” University of Medicine and Pharmacy, 32 Clinicilor Street, 400006 Cluj-Napoca, Romania
| | - Stanca Cuc
- Department of Polymer Composites, Institute of Chemistry “Raluca Ripan”, University Babes-Bolyai, 30 Fantanele Street, 400294 Cluj-Napoca, Romania
| | - Doina Prodan
- Department of Polymer Composites, Institute of Chemistry “Raluca Ripan”, University Babes-Bolyai, 30 Fantanele Street, 400294 Cluj-Napoca, Romania
| | - Marioara Moldovan
- Department of Polymer Composites, Institute of Chemistry “Raluca Ripan”, University Babes-Bolyai, 30 Fantanele Street, 400294 Cluj-Napoca, Romania
| | - Ioan Petean
- Faculty of Chemistry and Chemical Engineering, University Babes-Bolyai, 11 Arany János Street, 400028 Cluj-Napoca, Romania
| | - Anca Labunet
- Department of Prosthetic Dentistry and Dental Materials, “Iuliu Hatieganu” University of Medicine and Pharmacy, 32 Clinicilor Street, 400006 Cluj-Napoca, Romania
| | - Lucian Barbu Tudoran
- Department of Molecular Biology and Biotechnology, Electron Microscopy Laboratory, Biology and Geology Faculty, Babes-Bolyai University, 5–7 Clinicilor Str., 400006 Cluj-Napoca, Romania
- Electron Microscopy Integrated Laboratory, National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, 400293 Cluj-Napoca, Romania
| | - Iulia Clara Badea
- Dental Prevention Department, Faculty of Dental Medicine, “Iuliu Hatieganu” University of Medicine and Pharmacy, Avram Iancu 31, 400083 Cluj-Napoca, Romania
| | - Sorin Claudiu Man
- Mother and Child Department, 3Rd Department of Paediatrics, “Iuliu Hatieganu” University of Medicine and Pharmacy, 2-4 Campeni Street, 400217 Cluj-Napoca, Romania
| | - Mîndra Eugenia Badea
- Dental Prevention Department, Faculty of Dental Medicine, “Iuliu Hatieganu” University of Medicine and Pharmacy, Avram Iancu 31, 400083 Cluj-Napoca, Romania
| | - Radu Chifor
- Dental Prevention Department, Faculty of Dental Medicine, “Iuliu Hatieganu” University of Medicine and Pharmacy, Avram Iancu 31, 400083 Cluj-Napoca, Romania
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14
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Warnecki M, Sarul M, Kozakiewicz M, Zięty A, Babiarczuk B, Kawala B, Jurczyszyn K. Surface Evaluation of Aligners after Immersion in Coca-Cola and Orange Juice. MATERIALS (BASEL, SWITZERLAND) 2022; 15:ma15186341. [PMID: 36143665 PMCID: PMC9504463 DOI: 10.3390/ma15186341] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/09/2022] [Accepted: 09/12/2022] [Indexed: 05/31/2023]
Abstract
Orthodontic removable appliances made of transparent thermoplastic materials-aligners-are becoming increasingly popular in contemporary orthodontic practice. It is important for the clinician to fully understand the mechanical properties and behavior of the appliance used. Because of that, the aim of our study was to investigate the changes in aligner surface after immersion in Coca-Cola and orange juice. For surface evaluation, fractal analysis, texture analysis, and wetting angle measurement were performed. Statistically significant changes were found between some of the groups in the fractal dimension analysis. In texture analysis, all but one intergroup comparison showed statistically significant differences. For wetting angle assessment, statistically significant differences were found. These were, however, more numerous when assessing glycol droplets, rather than water droplets. Fractal dimension analysis confirmed a correlation between the intensity of changes in the aligner surface with immersion time in the liquids assessed. Texture analysis showed a high sensitivity to the changes in aligner surface. It failed, however, to reveal changes relative to immersion time. Wetting angle analysis revealed aligner surface degradation for Coca-Cola. It did not, however, prove the dependence of the intensity of this degradation as a function of time. Both Coca-Cola and orange juice can cause aligner surface degradation.
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Affiliation(s)
- Maciej Warnecki
- Independent Researcher, Niemodlińska 63, 45-864 Opole, Poland
| | - Michał Sarul
- Department of Integrated Dentistry, Wrocław Medical University, 50-425 Wrocław, Poland
| | - Marcin Kozakiewicz
- Department of Maxillofacial Surgery, Medical University of Lodz, 113 Żeromskiego Str., 90-549 Lodz, Poland
| | - Anna Zięty
- Department of Mechanics, Materials and Biomedical Engineering, Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Smoluchowskiego 25, 50-372 Wrocław, Poland
| | - Bartosz Babiarczuk
- Department of Mechanics, Materials and Biomedical Engineering, Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Smoluchowskiego 25, 50-372 Wrocław, Poland
| | - Beata Kawala
- Department of Dentofacial Orthopedics and Orthodontics, Wrocław Medical University, Krakowska 26, 50-425 Wrocław, Poland
| | - Kamil Jurczyszyn
- Department of Oral Surgery, Wrocław Medical University, Krakowska 26, 50-425 Wrocław, Poland
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Performance of Rigid and Soft Transfer Templates Using Viscous and Fluid Resin-Based Composites in the Attachment Bonding Process of Clear Aligners. Int J Dent 2022; 2022:1637594. [PMID: 35190741 PMCID: PMC8858075 DOI: 10.1155/2022/1637594] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 01/09/2022] [Accepted: 01/17/2022] [Indexed: 12/17/2022] Open
Abstract
Objectives The study aims at assessing the accuracy of the process of attachment bonding in aligner treatments. The analysis leads to the error estimation in the faithful reproduction of master model attachments using two types of transfer templates and two light-curing resin-based composites usually used in orthodontics. Methods The authors have used two transfer templates made of two different materials. The first, named Leone-biocompatible thermoforming material hard/soft, has a lower Young's modulus and is labelled as soft, while the other, named Leone-biocompatible thermoforming material, is marked as rigid. The resin-based composites possess different mechanical and rheological properties. Specifically, Transbond™ XT Light Cure Paste Adhesive, 3M has a higher viscosity than the TetricEvoflow, Ivoclar Vivadent, a flowable nanohybrid composite. The authors attempt to estimate the performance ranking between the four possible couples obtained by combining the two light-curing resin-based composites and transfer templates. Each combination was repeated in six models and compared with twelve master models, resulting in 36 total samples. A 3-D laser scanner is used to generate a digital model of each model. The comparison between digital models is the base for a comparative assessment in terms of relative and absolute error. The relative error is estimated using scalar performance indicators ranging from 0 to 1, where 1 indicates the optimum matching. The absolute error estimated from the mean square error between the coordinates of each digital model yields the reproduction accuracy in micrometer. Furthermore, the authors attempted to assess the error distribution by evaluating the point-by-point difference between the digital models. Results This analysis aims at localizing the sources of error in the considered models. The use of Transbond™ XT Light Cure Paste Adhesive, 3M with a rigid transfer template is always associated with significant accuracy and minor dispersion. However, in a few instances, using the soft template or the flowable resin-based composite can lead to bad performances. Significance. The data processing bestowed the following performance ranking from the first with lower reproduction error to the last characterized by the worst performance: (1) attachments bonding with rigid template and Transbond™ XT Light Cure Paste Adhesive, 3M, (2) attachments bonding with soft template and Transbond™ XT Light Cure Paste Adhesive, 3M, (3) attachments bonding with rigid template and TetricEvoflow, Ivoclar Vivadent, and (4) attachments bonding with soft template and TetricEvoflow, Ivoclar Vivadent.
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16
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Yu X, Li G, Zheng Y, Gao J, Fu Y, Wang Q, Huang L, Pan X, Ding J. “Invisible” orthodontics by polymeric “clear” aligners molded on 3D-printed personalized dental models. Regen Biomater 2022; 9:rbac007. [PMID: 35414958 PMCID: PMC8992363 DOI: 10.1093/rb/rbac007] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/17/2022] [Accepted: 01/21/2022] [Indexed: 12/03/2022] Open
Abstract
The malalignment of teeth is treated classically by metal braces with alloy wires, which has an unfavorable influence on the patients appearance during the treatment. With the development of digitization, computer simulation and three-dimensional (3D) printing technology, herein, a modern treatment was tried using clear polymeric aligners, which were fabricated by molding polyurethane films via thermoforming on the 3D-printed personalized dental models. The key parameters of photocurable 3D printing of dental models and the mechanical properties of the clear aligner film material were examined. The precision of a 3D-printed dental model mainly relied on characteristics of photocurable resin, the resolution of light source and the exposure condition, which determined the eventual shape of the molded clear aligner and thus the orthodontic treatment efficacy. The biocompatibility of the polyurethane film material was confirmed through cytotoxicity and hemolysis tests in vitro. Following a series of 3D-printed personalized dental models and finite element analysis to predict and plan the fabrication and orthodontic processes, corresponding clear aligners were fabricated and applied in animal experiments, which proved the efficacy and biocompatibility in vivo. Clinical treatments of 120 orthodontic cases were finally carried out with success, which highlights the advantage of the clear aligners as an esthetic, compatible and efficient appliance. ![]()
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Affiliation(s)
- Xiaoye Yu
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Guanghui Li
- Department of Orthodontics, Shanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, 200011, China
| | - Yikan Zheng
- Angelalign Research Institute, Shanghai, 200438, China
| | - Jingming Gao
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Ye Fu
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Qunsong Wang
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Lei Huang
- Angelalign Research Institute, Shanghai, 200438, China
| | - Xiaogang Pan
- Department of Orthodontics, Shanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, 200011, China
| | - Jiandong Ding
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
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17
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Color Stability, Chemico-Physical and Optical Features of the Most Common PETG and PU Based Orthodontic Aligners for Clear Aligner Therapy. Polymers (Basel) 2021; 14:polym14010014. [PMID: 35012036 PMCID: PMC8747426 DOI: 10.3390/polym14010014] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 02/03/2023] Open
Abstract
It is difficult to find research papers collecting comparative results about characterization studies of clear aligners. Therefore, the aim of this paper is to provide the first comparative analysis of most commercial clear aligners, in terms of their stability towards intra-oral staining agents, their physicochemical and optical properties, as well as their water absorption behavior. Five types of aligners, characterized by different techniques, are considered: Erkodur, Essix Plastic, Ghost Aligner, Zendura, and Invisalign. The obtained results show that clear aligners are made up of PETG, semi rigid PU, and a mixture of PU and PETG, with different degrees of crystallinity which affect the transparency of each aligner. In particular, the PETG-based materials reveal the highest value of short-range order and the highest properties in terms of transparency in the visible range. After 14 days of immersion into red wine and coffee, PETG and PU-based aligners reveal a perceivable change in color (NBS values from 1.5 to 3), corresponding to a loss of transparency due to the deposition of impurities on the surface. These results are particularly marked for Invisalign, showing changes towards other colors (NBS up to 35), probably due to the thermoforming process which led to the formation of a wrinkled surface entrapping the impurities.
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18
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Pratto I, Busato MCA, Bittencourt PRS. Thermal and mechanical characterization of thermoplastic orthodontic aligners discs after molding process. J Mech Behav Biomed Mater 2021; 126:104991. [PMID: 34864573 DOI: 10.1016/j.jmbbm.2021.104991] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 10/19/2022]
Abstract
Polymeric aesthetic aligners were introduced in orthodontics as an innovative alternative to fixed appliances, however, their compositions and the thermal molding process may influence the biomechanical characteristics of these aligners. In this study four different clear aligner brands were used, ACE 035 Essix, C + Essix, Crystal 0.75 and Crystal 1.0, whose aim was to identify the thermal-processing influence on the mechanical and physicochemical properties of these materials, and to suggest a orthodontic sequence of wear for these appliances to achieve more effective treatment results. For the tensile tests the sample size calculation was based on probability distributions from the F test. The effect size used was 0.3, type 1 error of 0.05. Statistical Yield strength and Young's Modulus results were evaluated using the Shapiro-Wilk test. The groups were compared using the parametric test of analysis of variance, with Tukey post-test. Differences were statistically considered at the p < 0.05. The Infrared spectroscopy analysis showed no changes in the samples' chemical structure after thermal-processing. However, in the polypropylene aligner, differences were verified in the region attributed to the crystalline phase. Differential Scanning Calorimetry analysis for the same sample showed a crystallinity fraction decrease due to relaxation between polymer chains after molding. In the tensile tests evaluated, the tensile strength and 'Young's modulus presented higher values for aligners containing 100% polyethylene terephthalate glycol. Performing an analogy exercise of the properties of orthodontic wires used in conventional fixed appliances and, relating them to orthodontic plastics, aligners composed of different materials and/or thicknesses could be used in increasing sequence in terms of the modulus of elasticity, starting with C+, which has a lower elastic modulus value, using the ACE 035 as an intermediate and finishing with the Crystal 0.75 and 1.0, providing the desired stiffness to the aligners for the final phase.
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Affiliation(s)
- Isabella Pratto
- Universidade Estadual do Oeste do Paraná (UNIOESTE), Departamento de Odontologia, ZIP 85819-110, Cascavel, Paraná, Brazil
| | - Mauro Carlos Agner Busato
- Universidade Estadual do Oeste do Paraná (UNIOESTE), Departamento de Odontologia, ZIP 85819-110, Cascavel, Paraná, Brazil
| | - Paulo Rodrigo Stival Bittencourt
- Universidade Tecnológica Federal do Paraná (UTFPR), Departamento Acadêmico de Química, Bloco I4, ZIP 85884-000, Medianeira, Paraná, Brazil.
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Hotta M, Murase Y, Shimizu S, Kusakabe S, Takagaki T, Nikaido T. Color changes in bulk-fill resin composites as a result of visible light-curing. Dent Mater J 2021; 41:11-16. [PMID: 34334507 DOI: 10.4012/dmj.2021-032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We evaluated twelve commercially available bulk-fill resin composites to determine the colorimetric changes that occurred as a result of the photo-polymerization reaction. Samples of the resin composites were prepared as disks 8 mm in diameter and 3 mm in thickness. A colorimeter was used to measure the color of samples on a black background before and after the polymerization processed had been initiated. As results, each of the photo-initiated bulk-fill resin composites tested except for Beautifil Bulk A showed a significant color difference more than that of conventional resin composites. Bulk Base Flow became darker, whereas Beautifil Bulk Flow became clearly lighter. All resin composites except for Bulk Base Flow became less yellow. Thus, Beautifil Bulk A exhibited the least color change among all the bulk-fill resin composites. However, this color change showed a marked change (NBS units) as observed by the human naked eye.
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Affiliation(s)
| | - Yuki Murase
- Division of Oral Functional Science and Rehabilitation, Department of Operative Dentistry, Asahi University School of Dentistry
| | - Shojiro Shimizu
- Division of Oral Functional Science and Rehabilitation, Department of Operative Dentistry, Asahi University School of Dentistry
| | - Shusuke Kusakabe
- Division of Oral Functional Science and Rehabilitation, Department of Operative Dentistry, Asahi University School of Dentistry
| | - Tomohiro Takagaki
- Division of Oral Functional Science and Rehabilitation, Department of Operative Dentistry, Asahi University School of Dentistry
| | - Toru Nikaido
- Division of Oral Functional Science and Rehabilitation, Department of Operative Dentistry, Asahi University School of Dentistry
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Dalaie K, Fatemi SM, Ghaffari S. Dynamic mechanical and thermal properties of clear aligners after thermoforming and aging. Prog Orthod 2021; 22:15. [PMID: 34180030 PMCID: PMC8236420 DOI: 10.1186/s40510-021-00362-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/12/2021] [Indexed: 11/10/2022] Open
Abstract
Background Based on the role of properties of aligner materials on their efficiency, we aimed to assess their thermomechanical properties after thermoforming and simulated aging. Methods In this experimental study, 96 samples of polyethylene terephthalate glycol (PETG) aligners (Duran and Erkodur) were prepared and divided to three groups: control (C), after thermoforming (T), after thermoforming and aging (TA). Thermoforming was done through 3D-printed molds, and aging was exerted by 200 thermal cycles after immersion in 37°C distilled water for 24h. Flexural modulus, hardness, glass transition temperature (Tg), elastic and viscous modulus, and loss factor were evaluated. Two-way ANOVA, T-independent, and Tukey HSD tests were done for statistical analysis and significance level was set to 0.05. Results In both materials, flexural modulus decreased significantly after thermoforming, 88% in Duran and 70% in Erkodur, but did not change significantly after aging. After thermoforming, hardness decreased significantly in both materials (22% in Duran and 7.6% in Erkodur). Dynamic Tg was significantly lower in T and TA in both materials. At all temperatures (25, 37, 55°C) in Duran, the elastic modulus difference was only significant between C and TA, but in Erkodur, it decreased significantly in T, and there was no significant change after aging. Viscous modulus and loss factor showed the same change patterns at all temperatures. In both materials, they increased after thermoforming, but did not change significantly after aging. Conclusion Thermoforming had more prominent role than aging in diminishing of thermomechanical properties. In general, Duran had greater thermomechanical stability than Erkodur.
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Affiliation(s)
- Kazem Dalaie
- Department of Orthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Daneshju Boulevard, Velenjak District, Tehran, Iran
| | - Seyyed Mostafa Fatemi
- Department of Dental Biomaterials, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Samin Ghaffari
- Department of Orthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Daneshju Boulevard, Velenjak District, Tehran, Iran. .,Dentofacial Deformities Research Center, Research Institute of Dental Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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ATR-FTIR Analysis of Orthodontic Invisalign ® Aligners Subjected to Various In Vitro Aging Treatments. MATERIALS 2021; 14:ma14040818. [PMID: 33572096 PMCID: PMC7914755 DOI: 10.3390/ma14040818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/03/2021] [Accepted: 02/04/2021] [Indexed: 11/16/2022]
Abstract
Clear and removable tooth aligners for orthodontics treatments have become an increasingly popular alternative to fixed appliances. Even if protocols suggest removing aligners before eating or drinking, most patients retain them when they drink beverages. Alterations in the material during the daily use could determine a reduction in the application forces, affecting the desired orthodontic movement; the knowledge of how this material reacts when subjected to different aging processes is mandatory to establish the predictability of the orthodontic treatment. According to this, the aim of the present study was to assess a new objective approach, coupling spectroscopic and chemometric tools, to evaluate the changes occurring in Invisalign® aligners, the most widely used brand, exposed in vitro to coffee, tea, Coca Cola® and UV radiation for 24 and 48 h. In particular, ATR-FTIR spectroscopy was utilized to characterize, at the molecular level, the chemical and color modifications in the surfaces of the appliances; the obtained data were submitted to PCA and one-way ANOVA and Tukey's multiple comparison test. Moreover, a colorimetry analysis was carried out to evaluate any changes in color and transparency. Coffee and tea samples displayed the major color changes between the tested groups. The differences highlighted in the spectral features of coffee, tea and UV-treated samples were mainly ascribable to color and transparency changes, because the chemical properties remained unaltered.
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Isola G. The Impact of Diet, Nutrition and Nutraceuticals on Oral and Periodontal Health. Nutrients 2020; 12:nu12092724. [PMID: 32899964 PMCID: PMC7551041 DOI: 10.3390/nu12092724] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 08/28/2020] [Indexed: 02/07/2023] Open
Abstract
Oral and periodontal diseases can determine severe functional, phonatory and aesthetic impairments and are the main cause of adult tooth loss. They are caused by some specific bacteria that provoke an intense local inflammatory response and affect-with particular gravity-susceptible subjects, because of reasons related to genetics and lifestyles (e.g., smoking and home oral hygiene habits). They are more frequent in the disadvantaged segments of society and, in particular, in subjects who have difficulty accessing preventive services and dental care. Some systemic diseases, such as uncontrolled diabetes, can increase their risk of development and progression. Recently, in addition to the obvious considerations of severe alterations and impairments for oral health and well-being, it has been noted that periodontitis can cause changes in the whole organism. Numerous clinical and experimental studies have highlighted the presence of a strong association between periodontitis and some systemic diseases, in particular, cardiovascular diseases, diabetes, lung diseases and complications of pregnancy. The purpose of this editorial is to provide a current and thoughtful perspective on the relationship of diet and natural agents on oral, periodontal diseases, and chewing disorder preventions which may reflect good systemic conditions and related quality of life or to analyze indirect effects through the contribution of diet and nutrition to systemic health in order to obtain a modern diagnostic-therapeutic approach.
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Affiliation(s)
- Gaetano Isola
- Department of General Surgery and Surgical-Medical Specialties, School of Dentistry, University of Catania, Via S. Sofia 78, 95124 Catania, Italy
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