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Kaur H, Khurelbaatar T, Mah J, Heo G, Major PW, Romanyk DL. In vitro biomechanics of divot use, and their placement, in orthodontic aligner therapy. Orthod Craniofac Res 2024; 27:527-534. [PMID: 38299945 DOI: 10.1111/ocr.12760] [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] [Accepted: 01/16/2024] [Indexed: 02/02/2024]
Abstract
INTRODUCTION To evaluate biomechanics of an aligner utilizing divots and the effect of their vertical placement on the right maxillary central incisor. METHODS An in vitro Orthodontic SIMulator (OSIM) was used to test forces and moments generated by aligners incorporating divots. The OSIM arch was scanned to generate a. STL version that was modified to create four models by placing divots on different positions of the right central maxillary incisor: GI - divots on gingival-third of lingual surface and incisal-third of labial surface; GM - divots on gingival-third of lingual surface and middle-third of labial surface; MI - divots on middle-third of lingual surface and incisal-third of labial surface; MM - divots on middle-third of lingual surface and middle-third of labial surface. Aligners (n = 30/model) were fabricated using a 0.75 mm thick polyethylene terephthalate material and Biostar® machine following the manufacturer's recommendations. A one-way MANOVA followed by one-way ANOVA (α = 0.05) was utilized to test effect of models on buccolingual force (Fy) and mesiodistal moment (Mx) at 0.20 mm of lingual displacement of the right maxillary central incisor. RESULTS Mean Mx for GI (-5.68 ± 7.38 Nmm), GM (3.75 ± 5.54 Nmm), MI (-4.27 ± 1.48 Nmm) and MM (1.96 ± 0.99 Nmm) models showed statistical differences between GI and GM, GI and MM, GM and MI and MI and MM. GI exerted the largest Fy (1.87 ± 0.75 N) followed by GM (1.10 ± 0.47 N), MI (0.70 ± 0.23 N) and MM (0.28 ± 0.08 N) with significant differences between GI and GM, GI and MI, GI and MM and GM and MM models. CONCLUSIONS Vertical divot placement on a right central incisor had a significant effect on aligner biomechanics. Buccolingual forces exerted by models GI, GM and MI were within the range suggested by literature for bodily tooth movement without major root tipping for GM and MI models.
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Affiliation(s)
- Harsimrat Kaur
- Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Tsolmonbaatar Khurelbaatar
- Faculty of Engineering - Mechanical Engineering Department, University of Alberta, Edmonton, Alberta, Canada
| | - James Mah
- School of Dental Medicine, University of Nevada, Las Vegas, Nevada, USA
| | - Giseon Heo
- Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Paul W Major
- Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Dan L Romanyk
- Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
- Faculty of Engineering - Mechanical Engineering Department, University of Alberta, Edmonton, Alberta, Canada
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Nagib R, Farkas AZ, Szuhanek C. Finite element analysis of the mechanical behavior of 3D printed orthodontic attachments used in aligner treatment. Sci Rep 2024; 14:14877. [PMID: 38937650 PMCID: PMC11211347 DOI: 10.1038/s41598-024-65864-x] [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: 04/24/2024] [Accepted: 06/25/2024] [Indexed: 06/29/2024] Open
Abstract
The composite attachment loss during orthodontic clear aligner therapy is an adverse event that commonly happens in clinical practice and can affect the overall outcome and length of treatment. The aim of our research is to provide a basis for the further study of an innovative digital protocol and application method for orthodontic aligner attachments. Two 3D models were designed, one based on the proposed protocol and the other on the conventional method for aligner attachment application. Four attachment shapes were used to identify the maximum values for the von Mises equivalent stresses, the maximum displacements values and the areas in which these values were recorded through FEM analysis. The results of the mechanical simulation show lower values of von Mises stress recorded in the 3D printed attachments assemblies, independent of their shape, when simulated under the same boundary and load conditions. The trapezoidal prism shaped 3D printed model has a 3.7 times smaller displacement value (0.088 [mm]) compared to the adhesive resin model (0.326 [mm]). In conclusion, the proposed protocol for aligner attachments and the introduction of innovative materials is a promising method of solving conventional attachment problems in current orthodontic treatments.
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Affiliation(s)
- Riham Nagib
- Department of Orthodontics, Orthodontics Research Center 'ORTHO CENTER', "Victor Babeş" University of Medicine and Pharmacy Timişoara, Eftimie Murgu Sq. 2, 300041, Timişoara, Romania
| | - Andrei Zoltan Farkas
- Department of Mechatronics, University Politehnica Timişoara, 1 Mihai Viteazu Ave, 300222, Timişoara, Romania.
| | - Camelia Szuhanek
- Department of Orthodontics, Orthodontics Research Center 'ORTHO CENTER', "Victor Babeş" University of Medicine and Pharmacy Timişoara, Eftimie Murgu Sq. 2, 300041, Timişoara, Romania
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Castilhos JS, Gasparello GG, Mota-Júnior SL, Hartmann GC, Miyagusuku LFI, Pithon MM, Tanaka OM. Accessories in clear aligner therapy: Laypeople's expectations for comfort and satisfaction. J Dent Res Dent Clin Dent Prospects 2024; 18:102-109. [PMID: 39071215 PMCID: PMC11282201 DOI: 10.34172/joddd.40793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/20/2024] [Indexed: 07/30/2024] Open
Abstract
Background This study explored the layperson's perception of comfort, satisfaction, and willingness to use various accessories in clear aligner therapy. Methods A total of 267 people analyzed standardized intraoral photographs of a female model in orthodontic treatment using: 1) only clear aligner (CA), the control group; 2) clear aligner+attachments (AT); 3) clear aligners+Cl II elastics (EL); 4) clear aligner+hybrid treatment with esthetic braces (HEB); 5) Clear aligner+hybrid treatment with metallic braces (HMB); 6) clear aligner+mini-implants (MI); 7) clear aligner+mini-implants and elastics for intrusion (MIE). In addition, a social media questionnaire was distributed to assess the willingness to undergo orthodontic treatment with various accessories. Results There was a significant difference between CA and all the other groups (P<0.001), with CA being considered more comfortable and providing greater satisfaction compared to other accessories. Moreover, AT showed a significant difference in reducing treatment time compared to other groups. Conclusion The CA was the most comfortable, exhibiting a higher satisfaction rate and a greater willingness to use it. The AT therapy was perceived as more comfortable and was associated with higher satisfaction and a greater likelihood of use, especially if it resulted in reduced treatment time. On the other hand, the participants reported that the HMB, MI, and MIE accessories were less comfortable.
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Affiliation(s)
- Jussimar Scheffer Castilhos
- Department of Orthodontics, Medicine and Life Sciences School, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | - Gil Guilherme Gasparello
- Department of Orthodontics, Medicine and Life Sciences School, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | - Sergio Luiz Mota-Júnior
- Orthodontist, Private Practice, Juiz de Fora Federal University, Juiz de Fora, Minas Gerais, Brazil
| | - Giovani Ceron Hartmann
- Department of Orthodontics, Medicine and Life Sciences School, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | - Luiz Fernando Iyda Miyagusuku
- Undergraduate Student in Dentistry, Medicine and Life Sciences School, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | - Matheus Melo Pithon
- Department of Orthodontics, Southwest Bahia State University – UESB, Jequié, Bahia, Brazil
| | - Orlando Motohiro Tanaka
- Department of Orthodontics, Medicine and Life Sciences School, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
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Chen J, Zhu D, Zhao M, Cheng Z, Pan Y, Liu X. Three-dimensional finite element analysis of the optimal mechanical design for maximum inward movement of the anterior teeth with clear aligners. Sci Rep 2024; 14:13203. [PMID: 38851833 PMCID: PMC11162411 DOI: 10.1038/s41598-024-63907-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 06/03/2024] [Indexed: 06/10/2024] Open
Abstract
This study aims to refine clinical designs within clear aligner therapy, exploring the appropriate ratio of anterior tooth retraction to intrusion under maximum anchorage. Using a three-dimensional finite element model and evaluating 19 load scenarios with first premolar extraction, the research identifies the optimal force angle for anterior tooth retraction as 45 to 55°. For clinical planning, it is recommended to design a retraction of 0.19 mm combined with an intrusion of 0.16 mm to achieve anterior tooth retraction. This investigation is crucial for enhancing understanding of biomechanical principles in clear aligner orthodontics, offering significant insights for effective treatments.
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Affiliation(s)
- Jingcheng Chen
- Hefei Stomatological Hospital, Hefei, 230000, Anhui, People's Republic of China
- Wanan Medical College, Wuhu, 241000, Anhui, People's Republic of China
| | - Daoyu Zhu
- Hefei Stomatological Hospital, Hefei, 230000, Anhui, People's Republic of China
- Wanan Medical College, Wuhu, 241000, Anhui, People's Republic of China
| | - Mengli Zhao
- Hefei Stomatological Hospital, Hefei, 230000, Anhui, People's Republic of China
- Bengbu Medical College, Wuhu, 241000, Anhui, People's Republic of China
| | - Zhiheng Cheng
- Hefei Stomatological Hospital, Hefei, 230000, Anhui, People's Republic of China
- Wanan Medical College, Wuhu, 241000, Anhui, People's Republic of China
| | - Yan Pan
- Hefei Stomatological Hospital, Hefei, 230000, Anhui, People's Republic of China
- Hefei Dental Clinical College of Anhui Medical University, Hefei, 230000, Anhui, People's Republic of China
| | - Xin Liu
- Hefei Stomatological Hospital, Hefei, 230000, Anhui, People's Republic of China.
- Hefei Dental Clinical College of Anhui Medical University, Hefei, 230000, Anhui, People's Republic of China.
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Antonarakis GS, Zekeridou A, Kiliaridis S, Giannopoulou C. Periodontal considerations during orthodontic intrusion and extrusion in healthy and reduced periodontium. Periodontol 2000 2024. [PMID: 38831560 DOI: 10.1111/prd.12578] [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: 10/17/2023] [Revised: 04/30/2024] [Accepted: 05/13/2024] [Indexed: 06/05/2024]
Abstract
In patients with advanced periodontal disease, pathological tooth migration may occur, which may require subsequent orthodontic treatment for both aesthetic and functional purposes. When planning orthodontic treatment mechanics, intrusive or extrusive forces are frequently indicated. Understanding tissue reactions during these movements is essential for clinicians when devising a comprehensive orthodontic-periodontal treatment plan. This knowledge enables clinicians to be fully aware of and account for the potential effects on the surrounding tissues. The majority of our understanding regarding the behavior of periodontal tissues in both healthy and compromised periodontal conditions is derived from animal studies. These studies offer the advantage of conducting histological and other assessments that would not be feasible in human research. Human studies are nevertheless invaluable in being able to understand the clinically relevant response elicited by the periodontal tissues following orthodontic tooth movement. Animal and human data show that in dentitions with reduced periodontal support, orthodontic intrusion of the teeth does not induce periodontal damage, provided the periodontal tissues do not have inflammation and plaque control with excellent oral hygiene is maintained. On the contrary, when inflammation is not fully controlled, orthodontic intrusion may accelerate the progression of periodontal destruction, with bacterial plaque remnants being displaced subgingivally, leading to further loss of attachment. Orthodontic extrusion, on the other hand, does not seem to cause further periodontal breakdown in dentitions with reduced periodontal support, even in cases with deficient plaque control. This is attributed to the nature of the tooth movement, which directs any plaque remnants coronally (supragingivally), reducing the risk of adverse effects on the periodontal tissues. This specific type of tooth movement can be leveraged to benefit periodontal conditions by facilitating the regeneration of lost hard and soft periodontal tissues in a coronal direction. As a result, orthodontic extrusion can be employed in implant site development, offering an advantageous alternative to more invasive surgical procedures like bone grafting. Regardless of the tooth movement prescribed, when periodontal involvement is present, it is essential to prioritize periodontal therapy before commencing orthodontic treatment. Adequate plaque control is also imperative for successful outcomes. Additionally, utilizing light orthodontic forces is advisable to achieve efficient tooth movement while minimizing the risk of adverse effects, notably root resorption. By adhering to these principles, a more favorable and effective combined orthodontic-periodontal approach can be ensured. The present article describes indications, mechanisms, side effects, and histological and clinical evidence supporting orthodontic extrusion and intrusion in intact and reduced periodontal conditions.
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Affiliation(s)
- Gregory S Antonarakis
- Division of Orthodontics, University Clinics of Dental Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Alkisti Zekeridou
- Division of Regenerative Dental Medicine and Periodontology, University Clinics of Dental Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Stavros Kiliaridis
- Division of Orthodontics, University Clinics of Dental Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Department of Orthodontics and Dentofacial Orthopaedics, University of Bern, Bern, Switzerland
| | - Catherine Giannopoulou
- Division of Regenerative Dental Medicine and Periodontology, University Clinics of Dental Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Fausto da Veiga Jardim A, Curado de Freitas J, Estrela C. Surface wear and adhesive failure of resin attachments used in clear aligner orthodontic treatment. J Orofac Orthop 2024; 85:52-62. [PMID: 37314488 DOI: 10.1007/s00056-023-00471-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 04/02/2023] [Indexed: 06/15/2023]
Abstract
PURPOSE This study evaluated adhesive and cohesive failures and the surface wear of attachments employed in clear aligner treatment (CAT) using three-dimensional (3D) superimposition. METHODS In all, 3D models of 150 teeth were obtained from intraoral scans from patients undergoing CAT with at least 4 months between each scan. Of the initial sample, 25 teeth were discarded, and 125 teeth were included in the study. Superimpositions of each individual tooth at the first and second time points were made using computer-aided design (CAD) software (Meshmixer; Autodesk, Mill Valley, CA, USA). Analyses were performed to compare surface wear and failures related to type of attachment (optimized/conventional), dental group (molars/premolars/anterior teeth), and arch (mandibular/maxillary). Mann-Whitney and Kruskal-Wallis statistical tests were applied with significance set at 5%. RESULTS More surface wear was observed in conventional attachments, mandibular and anterior teeth with statistical significance for surface wear on the distal surface of conventional attachments (p < 0.05). Cohesive failure was observed in 10% of attachments, occurring most frequently on optimized attachments and molar teeth. Adhesive failure was observed in 10% of the samples, more frequently on conventional attachments and posterior teeth. CONCLUSION Attachment type (conventional vs. optimized) was significantly correlated with surface wear on the distal surface of the attachment. Arch (mandibular or maxillary) and group of teeth (anterior or posterior) showed no correlation with surface wear. Failure, both adhesive and cohesive, correlated with attachment type and group of teeth, but not with the arch in which they were located.
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Affiliation(s)
- Alexandre Fausto da Veiga Jardim
- Department of Stomatologic Sciences, Federal University of Goiás, Av. Universitária, s/n-Setor Leste Universitário, 74605-020, Goiânia, Brazil.
| | - Jairo Curado de Freitas
- Department of Stomatologic Sciences, Federal University of Goiás, Av. Universitária, s/n-Setor Leste Universitário, 74605-020, Goiânia, Brazil
| | - Carlos Estrela
- Department of Stomatologic Sciences, Federal University of Goiás, Av. Universitária, s/n-Setor Leste Universitário, 74605-020, Goiânia, Brazil
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Song JH, Lee JH, Joo BH, Choi YJ, Chung CJ, Kim KH. Treatment outcome comparison of Invisalign vs fixed appliance treatment in first premolar extraction patients. Am J Orthod Dentofacial Orthop 2024; 165:399-413. [PMID: 38142394 DOI: 10.1016/j.ajodo.2023.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 10/01/2023] [Accepted: 10/01/2023] [Indexed: 12/25/2023]
Abstract
INTRODUCTION In this study, we compared the dentitional changes after Invisalign and conventional orthodontic treatment with 4 first premolar extractions. METHODS This retrospective study included 57 patients whose orthodontic treatment involved the extraction of 4 first premolars because of bialveolar protrusion. A total of 27 patients were treated with Invisalign (mean age, 25.5 ± 5.2 years) and 30 patients with the fixed appliance (mean age, 24.4 ± 5.8 years). The angular and linear changes of the maxillary and mandibular central incisors, second premolars, first molars, and second molars were measured from the recordings on the basis of the lateral cephalograms taken before and after treatment. The angular changes of the canines and second premolars were measured using panoramic radiographs. RESULTS The overbite and interincisal angle increased significantly in the Invisalign group compared with in the conventional fixed appliance group (P <0.05). The maxillary central incisors showed increased lingual tipping in the Invisalign group (P <0.05), whereas there was no statistically significant difference in the angular change of the mandibular incisors between groups (P >0.05). The maxillary first and second molars showed mesial tipping in the Invisalign group (P <0.05). The maxillary second premolars, first and second molars, and the mandibular second molars showed mesial movement in the Invisalign group (P <0.05). CONCLUSIONS The Invisalign group showed more statistically significant lingual tipping of the maxillary central incisors, distal tipping of the maxillary canines, and mesial tipping of the maxillary first and second molars after maximum retraction of the anterior teeth compared with the fixed appliance group.
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Affiliation(s)
- Ji-Hye Song
- Department of Orthodontics, The Institute of Craniofacial Deformity, Yonsei University College of Dentistry, Seoul, South Korea
| | - Ji-Hyun Lee
- Department of Orthodontics, Gangnam Severance Dental Hospital, The Institute of Craniofacial Deformity, Yonsei University College of Dentistry, Seoul, South Korea
| | - Bo-Hoon Joo
- The Institute of Clear Aligner Center of The STAR 28 Dental Group, Seoul, South Korea
| | - Yoon Jeong Choi
- Department of Orthodontics, The Institute of Craniofacial Deformity, Yonsei University College of Dentistry, Seoul, South Korea
| | - Chooryung J Chung
- Department of Orthodontics, Gangnam Severance Dental Hospital, The Institute of Craniofacial Deformity, Yonsei University College of Dentistry, Seoul, South Korea
| | - Kyung-Ho Kim
- Department of Orthodontics, Gangnam Severance Dental Hospital, The Institute of Craniofacial Deformity, Yonsei University College of Dentistry, Seoul, South Korea.
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Mendes Ribeiro SM, Aragón MLSDC, Espinosa DDSG, Shibasaki WMM, Normando D. Orthodontic aligners: between passion and science. Dental Press J Orthod 2024; 28:e23spe6. [PMID: 38198351 PMCID: PMC10768648 DOI: 10.1590/2177-6709.28.6.e23spe6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 11/10/2023] [Indexed: 01/12/2024] Open
Abstract
INTRODUCTION The benefits and safety of using orthodontic aligners have been reported more by clinical experience and expert opinion than by scientific evidence. Another important aspect is that aligners are constantly evolving. It is important to obtain evidence that allows for new updates in manufacturing technology, in the development of new movement planning protocols, in the incorporation and design of attachments, and in the aid of skeletal anchorage. METHODS Evidence retrieved from six electronic databases (CINAHL, MEDLINE, EMBASE, Psych Info, the Cochrane Library and the Joanna Briggs Library) is presented by means of questions and answers. CONCLUSIONS There is evidence that the aligners presented different levels of difficulty in performing each type of movement, with rotational and vertical movements being the most difficult to perform. Regarding perception of pain due to tooth movement, it seems to have less impact at the beginning of treatment; but dealing with more phonoarticulatory changes seems to require more treatment time in more complex cases. Aligners do not prevent the occurrence of root resorption, although the incidence and severity of resorption may be reduced, making oral hygiene easier and accepting the risk of white spots, caries and periodontal disease. Given the conflicting evidence, the release of bisphenol-A from the aligner cannot be denied. Solutions must be found to reduce the environmental impact of aligners disposal. There is an urgent need for well-designed randomized controlled trials.
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Affiliation(s)
| | | | | | | | - David Normando
- Universidade Federal do Pará (UFPA), Departamento de Ortodontia (Belém/PA, Brazil)
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Lin G, Chen M, Guo N, Shi X. Three-dimensional measurement and analysis of Mandibular Molar Distalization assisted by micro-implant anchorage combined with clear aligner. Pak J Med Sci 2024; 40:455-460. [PMID: 38356811 PMCID: PMC10862430 DOI: 10.12669/pjms.40.3.7759] [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: 02/25/2023] [Revised: 05/15/2023] [Accepted: 11/16/2023] [Indexed: 02/16/2024] Open
Abstract
Objective To investigate the effect of micro-implant anchorage combined with a clear aligner on the efficiency of mandibular molar distalization and the protection of anterior teeth anchorage, provide reference for clinical scheme design. Methods This is a prospective study. Seventeen patients who were treated in the Orthodontics Department of the Hospital of Stomatology affiliated to Fujian Medical University from 2019 to 2021 and used Invisalign clear aligners to move mandibular molars distally were included and divided into two groups according to anchorage types: Group-A and Group-B. Group-A (ten cases) were treated without micro-implant anchorage, while Group-B (seven cases) were treated with micro-implant anchorage nails for enhanced anchorage. The effect of micro-implant anchorage on crown and root distal movement of mandibular molars and the difference in three-dimensional movement between mandibular molars and mandibular central incisors were analyzed. Results The crown distalization efficiency of mandibular first and second molars in Group-B was 68.66% and 71.02%, respectively, which were higher than those in Group-A(p<0.05). The mandibular central incisors in Group-A showed labial displacement and a small amount of elongation, while those in Group-B showed less anchorage loss(p<0.05). In Group-A, the crown was tilted in the distal direction and moved in the buccal direction during mandibular molar distalization(p<0.05). While in Group-B, the crown was tilted in the distal directio (p<0.05) and the mandibular second molar was depressed(p<0.05). Conclusion In the process of mandibular molar distalization assisted by micro-implant anchorage combined with a clear aligner, better protects the anchorage of the mandibular central incisor and improves the efficiency of the molar crown distalization.
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Affiliation(s)
- Gengbing Lin
- Gengbing Lin, Department of Stomatology, Fujian Provincial People’s Hospital, Affiliated People’s Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou 350004, Fujian, China
| | - Mengwei Chen
- Mengwei Chen, Department of Orthodontics, Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University & Institute of Stomatology, Fujian Medical University, Fuzhou 350004, Fujian, China
| | - Nan Guo
- Nan Guo, Department of Stomatology, Fujian Provincial People’s Hospital, Affiliated People’s Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou 350004, Fujian, China
| | - Xie Shi
- Xie Shi, Department of Orthodontics, Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University & Institute of Stomatology, Fujian Medical University, Fuzhou 350004, Fujian, China
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10
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Jaber ST, Hajeer MY, Burhan AS, Alam MK, Al-Ibrahim HM. Treatment effectiveness of young adults using clear aligners versus buccal fixed appliances in class I malocclusion with first premolar extraction using the ABO-Objective Grading System: A randomized controlled clinical trial. Int Orthod 2023; 21:100817. [PMID: 37837842 DOI: 10.1016/j.ortho.2023.100817] [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: 07/30/2023] [Revised: 09/18/2023] [Accepted: 09/25/2023] [Indexed: 10/16/2023]
Abstract
OBJECTIVE To compare the effectiveness of the clear aligners with the traditional fixed appliances in the treatment of premolars extraction complex cases using the American Board of Orthodontics Objective Grading System (ABO-OGS). MATERIAL AND METHODS A single-centre, 2-parallel groups RCT with two arms. Forty severe crowding patients (14 males, 26 females; mean age: 21.40±2.42) who required four first premolars extraction were included and randomly allocated into two treatment groups: clear aligners therapy group (CAT), and fixed appliances therapy group (FAT). Cases complexities were measured on pre-treatment records using the Discrepancy index (DI). Post-treatment records were evaluated using the American Board of Orthodontics Objective Grading System (ABO-OGS). Two sample t-tests and Fisher's Exact tests were used to test for significant differences between the two groups. The statistical significance was set at P < 0.006 using Bonferroni's correction. RESULTS For the DI, the mean scores were 32.25 (± 4.33) in the CAT group and 33 (± 7.92) in the FAT group. In the CAT group, the total OGS score ranged between 6-33 points with an average of 17.50(± 7.41), whereas the total score in the FAT group went between 4-30 points with an average of 12.89 (± 6.31) with no significant differences between the two groups (P=0.05). When comparison of the successful cases between the two groups was made, 11 cases received passing scores, and 9 cases received failing scores in the CAT group. Whereas in the FAT group, 17 cases received passing scores, and 3 received a failing score. No statistically significant differences were found in the passing rates between of the CAT and FAT groups (P = 0.421). CONCLUSIONS According to the ABO-OGS total scores, there was no significant difference between the clear aligners and fixed appliances in the treatment of class I severe crowding cases with first premolars extraction in young adults. There were no differences between the two techniques in the OGS components scores except for the occlusal contacts, which were significantly better with the fixed appliances. When comparing the number of successful and failed cases between the two groups, no significant differences were noted, with the fixed appliances having a 30% higher success rate than the clear aligners, which must be considered clinically when choosing between these two techniques in the complex orthodontic cases treatment.
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Affiliation(s)
- Samer T Jaber
- Department of Orthodontics, Faculty of Dentistry, Al-Wataniya Private University, Hama, Syria
| | - Mohammad Y Hajeer
- Department of Orthodontics, Faculty of Dentistry, University of Damascus, Damascus, Syria.
| | - Ahmad S Burhan
- Department of Orthodontics, Faculty of Dentistry, University of Damascus, Damascus, Syria
| | - Mohammad Khursheed Alam
- Orthodontic Division, Department of Preventive Dentistry, College of Dentistry, Jouf University, Sakaka 72345, Saudi Arabia
| | - Heba M Al-Ibrahim
- Department of Orthodontics, Faculty of Dentistry, University of Damascus, Damascus, Syria
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Groody JT, Lindauer SJ, Kravitz ND, Carrico CK, Madurantakam P, Shroff B, Darkazanli M, Gardner WG. Effect of clear aligner attachment design on extrusion of maxillary lateral incisors: A multicenter, single-blind randomized clinical trial. Am J Orthod Dentofacial Orthop 2023; 164:618-627. [PMID: 37610383 DOI: 10.1016/j.ajodo.2023.07.011] [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: 01/01/2023] [Revised: 07/01/2023] [Accepted: 07/01/2023] [Indexed: 08/24/2023]
Abstract
INTRODUCTION Extrusion of maxillary lateral incisors during aligner treatment is a difficult movement to achieve accurately. Despite recommendations regarding attachment design, few studies and no prospective trials compare predictability among attachments. This study aimed to compare the efficacy between optimized and horizontal attachment designs for achieving maxillary lateral incisor extrusion during clear aligner treatment. METHODS The study included maxillary lateral incisors in 3 orthodontic practices requiring at least 0.3 mm of extrusion during the first series of 20-25 aligners in patients aged ≥16 years who were scheduled to begin clear aligner treatment (Invisalign; Align Technology, San Jose, Calif). Teeth were randomly assigned to receive optimized (O), rectangular horizontal nonbeveled (H), rectangular horizontal incisally-beveled (HIB), or rectangular horizontal gingivally-beveled (HGB) attachments. After the first series, a blinded evaluator measured extrusion using superimpositions with initial and predicted models. Linear models determined the difference in the predicted extrusion percentage achieved on the basis of attachment design. Other covariates were patient age, sex, number of trays, and self-reported compliance. RESULTS Forty patients (74 teeth) were enrolled, and 38 patients (71 teeth) completed the study. Intraexaminer and interexaminer reliability for extrusion measurements was high (intraclass correlation coefficient, 0.985 and 0.991, respectively). The achieved extrusion was significantly less than predicted (mean, 73%; P <0.0001). The average achieved extrusion was 62%, 79%, 78%, and 78% for O, H, HIB, and HGB attachments, respectively, with H significantly more effective than O (P = 0.0403). Horizontal attachments (H, HIB, and HGB combined) were significantly more effective than O attachments (P = 0.0060), with an average difference in achieved extrusion of 14% of the predicted amount (95% confidence interval, 4-23; estimated 76% vs 62%). Horizontal attachments were an estimated 22% more effective than O attachments for extruding maxillary lateral incisors. CONCLUSIONS Horizontal attachments are more effective than O attachments for predicted maxillary lateral incisor extrusion between 0.3 and 2.5 mm. The 3 horizontal attachment designs evaluated performed similarly for achieving predicted extrusion. TRIAL REGISTRATION This randomized clinical trial was registered and reported at clinicaltrials.gov (NCT04968353). PROTOCOL The protocol was not published before trial commencement. FUNDING This study was funded in part by the Alexander Fellowship of the Virginia Commonwealth University School of Dentistry, the Southern Association of Orthodontists, and the Virginia Orthodontic Education and Research Foundation. No funding source influenced the study design, the collection, analysis or interpretation of data, writing of the report, or the decision to submit the article for publication.
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Affiliation(s)
- Justin T Groody
- Formerly, Department of Orthodontics, School of Dentistry, Virginia Commonwealth University, Richmond, Va; currently, Private practice, Charlotte, NC
| | - Steven J Lindauer
- Department of Orthodontics, School of Dentistry, Virginia Commonwealth University, Richmond, Va.
| | | | - Caroline K Carrico
- Department of Public Health and Policy, School of Dentistry, Virginia Commonwealth University, Richmond, Va
| | | | - Bhavna Shroff
- Department of Orthodontics, School of Dentistry, Virginia Commonwealth University, Richmond, Va
| | - Manar Darkazanli
- School of Dentistry, Virginia Commonwealth University, Richmond, Va
| | - William Graham Gardner
- Formerly, Department of Orthodontics, School of Dentistry, Virginia Commonwealth University, Richmond, Va; currently, Private practice, Charlotte, NC; Private practice, Richmond, Va
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Bellocchio AM, Portelli M, Ciraolo L, Ciancio E, Militi A, Peditto M, Barbera S, Nucera R. Evaluation of the Clinical Variables Affecting Attachment Reproduction Accuracy during Clear Aligner Therapy. MATERIALS (BASEL, SWITZERLAND) 2023; 16:6811. [PMID: 37895792 PMCID: PMC10607942 DOI: 10.3390/ma16206811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/09/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023]
Abstract
BACKGROUND The purpose of this study was to evaluate some of the clinical variables that influence the accuracy of reproducing the planned attachment shape. The following clinical variables were considered: the template material, type of composite, and pressure application on the template during attachment curing. METHODS In this study, the evaluated materials for the thermoplastic transfer template construction are Erkolen 0.8 (polyethylene: PE) and Erkodur 0.8 (polyethylene terephthalate glycol-PET-G), and two types of composite resins: Enaflow (light-curing low-viscosity composite resin) and Enamel plus dentina HRI (light-curing high-viscosity composite resin). Two different light-curing lamps were used: Valo cordless color with no pressure and push light pressure (SCS). The 26 models included in the study were imported into the 3 Shape Ortho System 2022 (ver. 85.0.20 3 Shape, Denmark), and attachments were virtually placed on the dental elements of the first premolar and on both sides of the first upper molars. The accuracy of the attachment reproduction was evaluated through linear and angular evaluations against the reference model (MCAD). Three physical models were obtained: model A (MA), which was printed with attachments; model B (MB) with attachments made with a PE template; and model C (MC) with attachments made with a PET-G template. RESULTS The results showed statistically significant differences (p < 0.05) between the PE and PET-G templates with greater precision using the PET-G template. Statistically significant differences (p < 0.05) were found among the high-viscosity composite and low-viscosity composite with pressure curing. CONCLUSIONS In light of the obtained data, using a PET-G template is recommended. The pressure application during composite curing reduces the reproduction accuracy with a low-viscosity composite.
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Affiliation(s)
- Angela Mirea Bellocchio
- Department of Biomedical Sciences, Dentistry and Morphological and Functional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (M.P.); (L.C.); (E.C.); (A.M.); (M.P.); (S.B.); (R.N.)
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13
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Özsoy S, Pamukçu H, Polat-Özsoy Ö, Ateş EM. Color changes of nanocomposites used for clear aligner attachments: an in vitro study. J Orofac Orthop 2023; 84:266-275. [PMID: 36912962 DOI: 10.1007/s00056-023-00461-7] [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: 06/26/2022] [Accepted: 01/25/2023] [Indexed: 03/14/2023]
Abstract
PURPOSE The purpose of this study was to compare the color changes of two different nanocomposites used for two different designs of clear aligner attachments. METHODS In all, 120 human premolars were embedded in 12 upper dental models with 10 premolars in each model. Models were scanned and attachments were digitally designed. Conventional attachments (CA) were prepared for the first six models and optimized multiplane attachments (OA) were prepared for the other six models with packable composite (PC) on the right quadrant and flowable composite (FC) on the left quadrant of each model. The models were subjected to 2000 thermal cycles at 5 °C/55 °C and then consecutively immersed in the five different staining solutions each for 48 h to simulate external discoloration. Color measurements were taken with a spectrophotometer. Color changes (∆E*ab) of the attachments before and after immersion were compared with the Commission Internationale de l'Éclairage L*a*b* (CIELAB) color space approach. RESULTS When ∆E*ab values were examined, no significant difference was observed between the groups according to the attachment type (P > 0.05). After the coloration process, the flowable composite group showed less coloration than the packable composite group for both attachment designs (P < 0.05). Color difference values after the staining procedure were significantly higher in the CA-PC and OA-PC groups compared to the CA-FC and OA-FC groups (P < 0.05). CONCLUSION Color change of the packable nanocomposite was more pronounced than that of the flowable nanocomposite for both attachment designs. Therefore, clear aligner attachments created using flowable nanocomposite can be recommended, especially in the anterior region where esthetics are important for the patient.
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Affiliation(s)
| | - Hande Pamukçu
- Department of Orthodontics, Faculty of Dentistry, Başkent University, Yukarıbahçelievler Mah. 82. Sokak No:26, 06490, Bahçelievler Ankara, Turkey.
| | - Ömür Polat-Özsoy
- Private practice, Ankara, Turkey
- Department of Orthodontics, Faculty of Dentistry, İzmir Tınaztepe University, Aydoğdu Mah. 1267/1 Sokak No:4, Buca, İzmir, Turkey
| | - Ece Mersan Ateş
- Department of Orthodontics, Faculty of Dentistry, Başkent University, Yukarıbahçelievler Mah. 82. Sokak No:26, 06490, Bahçelievler Ankara, Turkey
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Wang S, Huang Y, Fan D, Liu H, Yuan C, Yang L, Wang P. Effects of overtreatment with different attachment positions on maxillary anchorage enhancement with clear aligners: a finite element analysis study. BMC Oral Health 2023; 23:693. [PMID: 37749548 PMCID: PMC10521390 DOI: 10.1186/s12903-023-03340-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 08/22/2023] [Indexed: 09/27/2023] Open
Abstract
BACKGROUND The effect of attachment positions on anchorage has not been fully explored. The aim of the present study is to analyze the effect of overtreatment with different anchorage positions on maxillary anchorage enhancement with clear aligners in extraction cases. METHODS Models of the maxilla and maxillary dentition were constructed and imported into SOLIDWORKS software to create periodontal ligament (PDL), clear aligners, and attachments. Attachment positions on second premolars included: without attachment (WOA), buccal attachment (BA), and bucco-palatal attachment (BPA). Overtreatment degrees were divided into five groups (0°, 1°, 2°, 3°, 4°) and added on the second premolars. The calculation and analysis of the displacement trends and stress were performed using ANSYS software. RESULTS Distal tipping and extrusion of the canines, and mesial tipping and intrusion of the posterior teeth occurred during retraction. A strong anchorage was achieved in cases of overtreatment of 2.8° with BA and 2.4° with BPA. Moreover, the BPA showed the best in achieving bodily control of the second premolars. When the overtreatment was performed, the canines and first molars also showed reduced tipping trends with second premolars attachments. And the stress on the PDL and the alveolar bone was significantly relieved and more evenly distributed in the BPA group. CONCLUSIONS Overtreatment is an effective means for anchorage enhancement. However, the biomechanical effect of overtreatment differs across attachment positions. The BPA design performs at its best for stronger overtreatment effects with fewer adverse effects.
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Affiliation(s)
- Shiyu Wang
- School of stomatology, Xuzhou Medical University, 221000, Xuzhou, China
| | - Yangyang Huang
- School of stomatology, Xuzhou Medical University, 221000, Xuzhou, China
| | - Dian Fan
- School of stomatology, Xuzhou Medical University, 221000, Xuzhou, China
| | - Hao Liu
- Department of Orthodontics, Affiliated Stomatological Hospital of Xuzhou Medical University, 221000, Xuzhou, China
| | - Changyong Yuan
- School of stomatology, Xuzhou Medical University, 221000, Xuzhou, China
- Department of Implantology, Affiliated Stomatological Hospital of Xuzhou Medical University, 221000, Xuzhou, China
| | - Li Yang
- Department of Orthodontics, Affiliated Stomatological Hospital of Xuzhou Medical University, 221000, Xuzhou, China
| | - Penglai Wang
- School of stomatology, Xuzhou Medical University, 221000, Xuzhou, China.
- Department of Implantology, Affiliated Stomatological Hospital of Xuzhou Medical University, 221000, Xuzhou, China.
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AlMogbel A. Clear Aligner Therapy: Up to date review article. J Orthod Sci 2023; 12:37. [PMID: 37881665 PMCID: PMC10597356 DOI: 10.4103/jos.jos_30_23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 04/11/2023] [Accepted: 05/02/2023] [Indexed: 10/27/2023] Open
Abstract
The advantages of Clear Aligners Therapy (CAT) include the braces being virtually invisible, comfortable to wear, and removable for eating and brushing; that way, CAT can be used to treat a wide range of orthodontic issues. In 1999, the company Align Technology introduced the frst commercial clear aligner system called Invisalign. The Invisalign system was initially only available to orthodontists, but later became available to general dentists as well. The system quickly gained popularity among patients who were looking for a more discreet and comfortable alternative to traditional braces. In 2000, Align Technology received FDA clearance for the Invisalign system, which further increased its popularity. The biomechanics of clear aligners involve the use of custom-made tooth aligners that are specifcally shaped to guide teeth into desired positions. These aligners are typically made from flexible materials such as polyurethane or ethylene vinyl acetate and are adjusted to apply the necessary forces for tooth movement. Attachment devices, such as power ridges or buttons, are often used to enhance or assist in specifc tooth movements and for retention of the aligner. The use of attachments allows for the exertion of desired force on the teeth, which is crucial for the success of Clear Aligner Therapy. CAT should be used if patients are concerned about the esthetic appearances of their teeth-for example, actors and other individuals that rely on their appearances in public in a professional context-and if the misalignment is not severe, so that clear aligners can still work. One should not use CAT in cases of severe crowding or spacing issues that require extractions. If the patient has complex jaw discrepancies or skeletal issues or if teeth need to be moved extensively in multiple directions, CAT is likely not going to be strong enough. In conclusion, Clear Aligner Therapy is a safe, effective, and convenient orthodontic treatment option that offers patients a virtually invisible way to achieve a straighter, more beautiful smile. With continued advancements in technology and a growing body of research supporting its effectiveness, the future of Clear Aligner Therapy looks bright.
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Affiliation(s)
- AbdulMajeed AlMogbel
- Department of Orthodontics and Pediatric Dentistry, College of Dentistry, Qassim University, Buraydah 52571, Saudi Arabia
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16
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Ma S, Wang Y. Clinical outcomes of arch expansion with Invisalign: a systematic review. BMC Oral Health 2023; 23:587. [PMID: 37620781 PMCID: PMC10464440 DOI: 10.1186/s12903-023-03302-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 08/10/2023] [Indexed: 08/26/2023] Open
Abstract
OBJECTIVE This study aims to assess the scientific evidence regarding the clinical outcomes of Invisalign therapy in controlling orthodontic tooth movement. MATERIALS AND METHODS An electronic search was conducted on PubMed, Cochrane Library, Web of Science, Embase, and Scopus from November 2015 to November 2022 to identify relevant articles. Methodological shortcomings were highlighted, and an evaluation of the quality of the included studies was completed using the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool. RESULTS Fifteen non-randomized controlled trials were included in the analysis. Most non-randomized controlled trials (n=11; 73%) were rated with a moderate risk of bias according to the ROBINS-I tool. There were statistically significant differences between the pretreatment and posttreatment arches. The average expansion was significantly different from that predicted for each type of tooth in both the maxilla and mandible. Furthermore, the efficiency decreased from the anterior area to the posterior area in the upper arch. CONCLUSION Despite the fact that arch expansion with Invisalign® is not entirely predictable, clear aligner treatment is a viable option for addressing dentition crowding. The efficacy of expansion is greatest in the premolar area. More research focusing on treatment outcomes with different materials of aligners should be conducted in the future. Overcorrection should be considered when planning arch expansion with Invisalign. In the maxilla, the expansion rate decreases from the anterior to the posterior, and presetting sufficient buccal root torque of posterior teeth may result in improved efficiency of expansion.
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Affiliation(s)
- Songyang Ma
- Department of Orthodontics, Stomatological Hospital of Chongqing Medical University, Chongqing, People's Republic of China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, People's Republic of China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, People's Republic of China
| | - Yunji Wang
- Department of Orthodontics, Stomatological Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, People's Republic of China.
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, People's Republic of China.
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McKay A, McCray J, Bankhead B, Lee MM, Miranda G, Adel SM, Kim KB. Forces and moments generated during extrusion of a maxillary central incisor with clear aligners: an in vitro study. BMC Oral Health 2023; 23:495. [PMID: 37461004 DOI: 10.1186/s12903-023-03136-2] [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: 04/14/2023] [Accepted: 06/14/2023] [Indexed: 07/20/2023] Open
Abstract
OBJECTIVE To assess the possibility of extrusion of a maxillary central incisor with the use of buccal and lingual pressure columns in the absence of attachments, and to evaluate the forces and moments experienced by the teeth using both thermoformed and 3D-printed clear aligners. MATERIALS AND METHODS A three-axis force and moment sensor (Aidin Robotics, Anyang, South Korea) was used to measure the forces and moments during extrusion of an upper left central incisor (UL1) and any forces experienced by the upper right central incisor (UR1) using thermoformed aligners and 3D-printed aligners. For the thermoformed aligners, the materials used were ATMOS® (American Orthodontics, Sheboygan, WI) and Zendura FLX® (Bay Materials LLC, Fremont, CA). 3D-printed aligners were fabricated using TC-85 clear photocurable resin (Graphy Inc., Seoul, South Korea). For each material type, three conditions were tested: Group 1: No attachment or pressure columns (control); Group 2: Attachment only; and Group 3: Pressure columns only. Each group was planned for 0.5 mm of extrusion on the UL1. RESULTS All force readings collected demonstrated statistically significant differences when compared by materials and when compared by groups, with a P value of < 0.001. In the absence of attachment or pressure columns (Group 1), ATMOS® and TC-85 groups exerted extrusive force on the UL1. However, significantly lower forces and moments were exerted by the TC-85 group in comparison to the ATMOS® and Zendura FLX® groups. In the presence of attachment (Group 2), all three ATMOS®, Zendura FLX® and TC-85 groups exerted extrusive force on the UL1, with the TA group showing different directions of faciolingual force, mesiodistal force and faciolingual inclination on the UR1 when compared to the other two thermoformed groups. Whereas in the presence of pressure columns (Group 3), only the TC-85 3D-printed aligner group exerted extrusive force. Thermoformed aligners generated significantly higher mean forces and moments than 3D-printed aligners. Significant levels of unintended forces and moments were present in all groups. CONCLUSIONS Force levels generated during extrusion with clear aligners are significantly lower with those 3D-printed using TC-85 than with those thermoformed using ATMOS® or Zendura FLX®. Attachments consistently generated extrusive forces, and may be an effective adjunct in achieving extrusion of incisors. Extrusion may be achieved without the use of attachments by utilizing pressure columns in 3D-printed aligners using TC-85. While different strategies can generate extrusive forces, there are significant unintended forces and moments.
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Affiliation(s)
- Abraham McKay
- Department of Orthodontics, Saint Louis University, Saint Louis, MO, USA
| | - Julie McCray
- Department of Orthodontics, Saint Louis University, Saint Louis, MO, USA
| | - Brent Bankhead
- Department of Orthodontics, Saint Louis University, Saint Louis, MO, USA
| | - Michael M Lee
- Department of Orthodontics, Saint Louis University, Saint Louis, MO, USA
| | - Gabriel Miranda
- Department of Orthodontics, Saint Louis University, Saint Louis, MO, USA
| | - Samar M Adel
- Department of Orthodontics, Saint Louis University, Saint Louis, MO, USA.
- Department of Orthodontics, Faculty of Dentistry, Alexandria University, Alexandria, Egypt.
| | - Ki Beom Kim
- Department of Orthodontics, Saint Louis University, Saint Louis, MO, USA
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Jedliński M, Mazur M, Greco M, Belfus J, Grocholewicz K, Janiszewska-Olszowska J. Attachments for the Orthodontic Aligner Treatment-State of the Art-A Comprehensive Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:4481. [PMID: 36901488 PMCID: PMC10001497 DOI: 10.3390/ijerph20054481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/25/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND In recent years the burden of aligner treatment has been growing. However, the sole use of aligners is characterized by limitations; thus attachments are bonded to the teeth to improve aligner retention and tooth movement. Nevertheless, it is often still a challenge to clinically achieve the planned movement. Thus, the aim of this study is to discuss the evidence of the shape, placement and bonding of composite attachments. METHODS A query was carried out in six databases on 10 December 2022 using the search string ("orthodontics" OR "malocclusion" OR "Tooth movement techniques AND ("aligner*" OR "thermoformed splints" OR "invisible splint*" AND ("attachment*" OR "accessor*" OR "auxill*" AND "position*"). RESULTS There were 209 potential articles identified. Finally, twenty-six articles were included. Four referred to attachment bonding, and twenty-two comprised the influence of composite attachment on movement efficacy. Quality assessment tools were used according to the study type. CONCLUSIONS The use of attachments significantly improves the expression of orthodontic movement and aligner retention. It is possible to indicate sites on the teeth where attachments have a better effect on tooth movement and to assess which attachments facilitate movement. The research received no external funding. The PROSPERO database number is CRD42022383276.
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Affiliation(s)
- Maciej Jedliński
- Department of Interdisciplinary Dentistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
- Department of Dental and Maxillofacial Sciences, Sapienza University of Rome, 00161 Rome, Italy
| | - Marta Mazur
- Department of Interdisciplinary Dentistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
- Department of Dental and Maxillofacial Sciences, Sapienza University of Rome, 00161 Rome, Italy
| | - Mario Greco
- Department of Paediatric Dentistry, University of L’Aquila, 67100 L’Aquila, Italy
| | - Joyce Belfus
- Faculty of Dentistry, Universidad de los Andes, Santiago 7620001, Chile
| | - Katarzyna Grocholewicz
- Department of Interdisciplinary Dentistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
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D’Antò V, Valletta R, Ferretti R, Bucci R, Kirlis R, Rongo R. Predictability of Maxillary Molar Distalization and Derotation with Clear Aligners: A Prospective Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:2941. [PMID: 36833638 PMCID: PMC9957205 DOI: 10.3390/ijerph20042941] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/05/2023] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
Clear aligners are employed daily for the treatment of Class II malocclusions, when a valid option involves distalization and derotation of the upper first and second molars. Evidence regarding the predictability of these movements is slight, and the treatment outcome that clinicians plan may not be achieved. Therefore, the purpose of this study is to assess the accuracy of distalization and derotation with clear aligners. Geomagic Control X, a 3D quality control software, was used to superimpose digital models of the pre-treatment, post-treatment, and virtual plan (ideal post-treatment) measurements of 16 patients (4 M, 12 F; mean age 25.7 ± 8.8 years). Linear and angular measurement tools were used to calculate the amount of tooth movement prescribed and achieved. Distal displacement of the buccal cusps had an overall accuracy of 69% for the first molar and 75% for the second molar. The accuracy of molar derotation was higher for the first molar (77.5%) than for the second molar (62.7%). The aligners were not able to achieve 100% of the ideal post-treatment result; thus, planning of refinements is often needed. However, clear aligners can be regarded as a valuable option for the distalization of first and second molars.
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Affiliation(s)
- Vincenzo D’Antò
- School of Orthodontics, Department of Neurosciences, Reproductive Sciences and Oral Sciences, University of Naples Federico II, Via Pansini, 5, 80131 Naples, Italy
| | - Rosa Valletta
- School of Orthodontics, Department of Neurosciences, Reproductive Sciences and Oral Sciences, University of Naples Federico II, Via Pansini, 5, 80131 Naples, Italy
| | - Roberto Ferretti
- School of Orthodontics, Department of Neurosciences, Reproductive Sciences and Oral Sciences, University of Naples Federico II, Via Pansini, 5, 80131 Naples, Italy
| | - Rosaria Bucci
- School of Orthodontics, Department of Neurosciences, Reproductive Sciences and Oral Sciences, University of Naples Federico II, Via Pansini, 5, 80131 Naples, Italy
| | | | - Roberto Rongo
- School of Orthodontics, Department of Neurosciences, Reproductive Sciences and Oral Sciences, University of Naples Federico II, Via Pansini, 5, 80131 Naples, Italy
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Clear Aligners and Smart Eye Tracking Technology as a New Communication Strategy between Ethical and Legal Issues. Life (Basel) 2023; 13:life13020297. [PMID: 36836654 PMCID: PMC9967915 DOI: 10.3390/life13020297] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/26/2023] Open
Abstract
Smart eye-tracking technology (SEET) that determines visual attention using smartphones can be used to determine the aesthetic perception of different types of clear aligners. Its value as a communication and comprehension tool, in addition to the ethical and legal concerns which it entails, can be assessed. One hundred subjects (50 F, 50 M; age range 15-70) were equally distributed in non-orthodontic (A) and orthodontic (B) groups. A smartphone-based SEET app assessed their knowledge of and opinions on aligners. Subjects evaluated images of smiles not wearing aligners, with/without attachments and with straight/scalloped gingival margins, as a guided calibration step which formed the image control group. Subsequently, the subjects rated the same smiles, this time wearing aligners (experimental images group). Questionnaire data and average values for each group of patients, and images relating to fixation times and overall star scores, were analyzed using these tests: chi-square, t-test, Mann-Whitney U, Spearman's rho, and Wilcoxon (p < 0.05). One-way ANOVA and related post-hoc tests were also applied. Orthodontic patients were found to be better informed than non-orthodontic patients. Aesthetic perception could be swayed by several factors. Attachments scored lower in aesthetic evaluation. Lips distracted attention from attachments and improved evaluations. Attachment-free aligners were better rated overall. A more thorough understanding as to the opinions, expectations and aesthetic perception of aligners can improve communication with patients. Mobile SEET is remarkably promising, although it does require a careful medicolegal risk-benefit assessments for responsible and professional use.
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Happe A, Blender S, Luthardt RG. Orthodontic pretreatment with aligners for optimizing the result prior to fixed restorations in the esthetic zone. J ESTHET RESTOR DENT 2023; 35:279-290. [PMID: 36591901 DOI: 10.1111/jerd.12997] [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: 10/15/2022] [Revised: 11/26/2022] [Accepted: 11/28/2022] [Indexed: 01/03/2023]
Abstract
OBJECTIVE To show the benefit of a minor orthodontic pretreatment prior to fixed restorations in the esthetic zone in challenging situations. OVERVIEW Esthetic rehabilitations in complex situations need careful treatment planning and comprehensive interdisciplinary approach. Minor orthodontic pretreatments may transfer complex situations into straight forward situations. Typical indications are space opening in order to provide space for a restoration with anatomic proportion or corrections of the tooth axis. CONCLUSION This article presents three clinical cases that show how decision making can be facilitated by a functional and esthetic wax-up/mock-up workflow and how orthodontic pretreatment can contribute to a more functional, less invasive, and more esthetic outcome of restorative treatments in the esthetic zone. CLINICAL SIGNIFICANCE Some complex cases in restorative dentistry can be transformed to straight forward cases with the help of minor orthodontic tooth movements.
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Affiliation(s)
- Arndt Happe
- Dentist/Oral Surgeon, Dr. Happe & Kollegen, Münster, Germany.,Department of Prosthetic Dentistry, Center of Dentistry, University of Ulm, Ulm, Germany
| | - Sarah Blender
- Department of Prosthetic Dentistry, Center of Dentistry, University of Ulm, Ulm, Germany
| | - Ralph G Luthardt
- Department of Prosthetic Dentistry, Center of Dentistry, University of Ulm, Ulm, Germany
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22
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Omran R, Dowie A. Increased demand for orthodontic treatments during the COVID-19 pandemic: a commentary. Br Dent J 2023; 234:84-87. [PMID: 36707571 PMCID: PMC9880911 DOI: 10.1038/s41415-023-5451-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 12/07/2022] [Indexed: 01/28/2023]
Abstract
Despite the impact of the COVID-19 pandemic upon healthcare sectors generally, and what this continues to mean in particular for the practice of dentistry, there is evidence of an unanticipated upsurge in the demand for orthodontic treatment. This was observed in the UK and internationally as a manifestation of the so-called 'Zoom boom', in which video conferencing from home on various platforms suddenly exponentiated. As a result, it seems people became more self-conscious when viewing their appearance on-screen. Among the precipitating factors for individuals taking the consequent step of seeking orthodontic treatment are: the unavailability of more invasive smile enhancement treatments due to the pandemic restrictions; a more favourable infection control probability in orthodontic therapy; and the extra disposable funds that would otherwise be spent on holidays and leisure activities. This article explores different possible social and commercial drivers behind this phenomenon and suggests that the circumstances of the pandemic have shifted the pursuit of the desirable smile somewhat towards orthodontics, and as a consequence, is beneficial both to the public and the profession of dentistry as a whole.
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Affiliation(s)
- Rahaf Omran
- University of Glasgow Dental School, Glasgow Dental Hospital and School, 378 Sauchiehall Street, Glasgow, G2 3JZ, UK.
| | - Al Dowie
- Professor of Medical Ethics and Law, School of Medicine, Dentistry and Nursing, University of Glasgow, G12 8QQ, UK
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23
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Hertan E, McCray J, Bankhead B, Kim KB. Force profile assessment of direct-printed aligners versus thermoformed aligners and the effects of non-engaged surface patterns. Prog Orthod 2022; 23:49. [DOI: 10.1186/s40510-022-00443-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 10/24/2022] [Indexed: 11/30/2022] Open
Abstract
Abstract
Background
The purpose of the study was to measure the forces delivered by direct-printed aligners (DPA) in the vertical dimension and compare the force profile with traditional thermoformed aligners (TFA) and to investigate the impact of non-engaged surface patterns to the properties of DPA and TFA.
Methods
A force-measuring appliance was fabricated capable of displacing the aligner in 0.10 mm increments and measuring the resultant force. Polyethylene terephthalate glycol (ATMOS 0.030″ American Orthodontics) and TC-85DAC resin (Graphy Inc) were used to create TFA and DPA, respectively. Aligners were temperature-controlled prior to and during testing to simulate the oral environment. The resultant forces from displacements ranging from 0.10 to 0.30 mm were measured.
Results
At intraoral temperatures, DPA demonstrated significantly less force than TFA. TFA demonstrated a substantial statistically significant increase in force with each 0.10 mm increase in vertical displacement. DPA demonstrated a much more consistent force profile across the range of displacements. The effects of surface patterns in both DPA and TFA were generally a decrease in force. Statistical significance of surface patterns was detected for TFA at displacements of 0.30 mm and greater and significant for DPA only at a displacement of 0.10 mm. Surface patterns in both DPA and the TFA did not show any statistical difference when assessing force proprieties.
Conclusions
Forces delivered by aligners in the vertical dimension by DPA are more consistent and of lower magnitude than those of TFA aligners. Surface patterns were not capable of altering the force properties of both DPA and TFA.
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Liu JQ, Zhu GY, Wang YG, Zhang B, Wang SC, Yao K, Zhao ZH. Different biomechanical effects of clear aligners in bimaxillary space closure under two strong anchorages: finite element analysis. Prog Orthod 2022; 23:41. [DOI: 10.1186/s40510-022-00435-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 08/18/2022] [Indexed: 11/15/2022] Open
Abstract
Abstract
Background
Clear aligner (CA) treatment has been gaining popularity, but the biomechanical effects of CAs in bimaxillary dentition have not been thoroughly investigated. Direct and indirect strong anchorages are two common anchorage control methods, but the underlying biomechanical mechanism has not yet been elucidated. This study aimed to investigate the different biomechanical effects of CAs in closing the bimaxillary space under different anchorage controls, further instructing the compensation strategies design and strong anchorage choice in clinical practice.
Methods
Three-dimensional (3D) bimaxillary models of different anchorage controls were created based on cone-beam computed tomography and intraoral scan data. Four first premolars were extracted using 3D modeling software. Finite element analysis was conducted to simulate the space closure process of the CAs.
Results
In the two strong anchorage groups, the bimaxillary dentition presented different movement patterns during the space closure process, and the lower dentition was more vulnerable to elastic force. From the vertical view, direct strong anchorage with elastic force had the advantage of flattening the longitudinal occlusal curve and resisting the roller-coaster effects, whereas indirect strong anchorage could lead to a deep longitudinal occlusal curve. From the sagittal view, indirect strong anchorage with metallic ligaments had a greater instantaneous anchorage protection effect, particularly in the lower dentition, which reduced the mesial movement of the posterior teeth by nearly four times that of the direct anchorage group. In addition, indirect strong anchorage presented better anterior teeth torque/tipping control, while direct strong anchorage could aggravate lingual tipping of the upper central incisors. Due to the differences in anterior–posterior anchorage and arch shape, compared with the upper dentition, anchorage preservation and vertical control effects were amplified in the lower dentition.
Conclusions
The biomechanical effects of CAs differed between the two strong anchorage groups. Due to the differences in dentition morphology, anterior–posterior anchorage, and dental arch shape, CAs present different biomechanical effects in bimaxillary space closure. Orthodontists should consider the corresponding mechanical compensation according to specific anchorage control methods and dentitions.
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Fan D, Liu H, Yuan CY, Wang SY, Wang PL. Effectiveness of the attachment position in molar intrusion with clear aligners: a finite element study. BMC Oral Health 2022; 22:474. [PMID: 36348394 PMCID: PMC9644447 DOI: 10.1186/s12903-022-02472-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 09/22/2022] [Indexed: 11/09/2022] Open
Abstract
Objective To evaluate the biomechanical effects of different attachments’ position for maxillary molar intrusion with clear aligner treatment by finite element analysis. Methods Cone-beam computed tomography images of a patient with supra-eruption of the maxillary second molars were selected to construct three-dimensional models of the maxilla, periodontal ligaments, dentition, and clear aligner. The models were divided into four groups depending on the attachment location on the first molar: (1) no attachment (NA), (2) buccal attachment (BA), (3) palatal attachment (PA), and (4) bucco-palatal attachment (BPA). After applying an intrusion of 0.2 mm on the second molar, displacements and stress distributions of the teeth, aligner, and periodontal ligament were analyzed with the finite element software. Results All groups displayed equivalent movement patterns of aligners. The NA and BA groups showed buccal tipping of the second molar, while the PA group showed palatal tipping. The BPA group had the highest intruding value and the lowest buccal/palatal tipping value. All groups showed mesial tipping of the second molar. Stress distribution in the periodontal ligament strongly correlated with the attachment position. The BPA group showed the best stress distribution. Conclusion Combined BA and PA could effectively prevent buccal and palatal tipping and showed the best efficiency in intruding the second molar. The second molar showed an unavoidable tendency to tip mesially, regardless of the attachment position.
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Roberts WE, Chang CH, Chen J, Brezniak N, Yadav S. Integrating skeletal anchorage into fixed and aligner biomechanics. J World Fed Orthod 2022; 11:95-106. [DOI: 10.1016/j.ejwf.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 04/08/2022] [Indexed: 11/30/2022]
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Menéndez López-Mateos C, Menéndez López-Mateos ML, Aguilar-Salvatierra A, Gómez-Moreno G, Carreño JC, Khaldy H, Menéndez-Núñez M. Salivary Markers of Oxidative Stress in Patients Undergoing Orthodontic Treatment with Clear Aligners versus Self-Ligating Brackets: A Non-Randomized Clinical Trial. J Clin Med 2022; 11:jcm11123531. [PMID: 35743601 PMCID: PMC9225360 DOI: 10.3390/jcm11123531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/09/2022] [Accepted: 06/15/2022] [Indexed: 01/04/2023] Open
Abstract
The aim of this work was to determine advanced the oxidative protein products (AOPPs), total antioxidant capacity (TAC), and myeloperoxidase activity (MPO) in the saliva of patients undergoing orthodontic treatment with clear removable aligners in comparison with another group in treatment with fixed passive self-ligating brackets applying light forces, before treatment, after 30 days, and after 90 days of treatment. This non-randomized clinical trial recruited patients consecutively, all of which were over 18 years of age and due to undergo orthodontic treatment. They were divided into two groups according to treatment type: Group A, 48 patients treated with clear aligners (Invisalign®); and Group B, 19 patients treated with Damon System® 0.22″ self-ligating brackets applying light forces. Saliva samples were collected by a single clinician following the same protocol and underwent three analyses—AOPPs, TAC, and MPO levels–at baseline before placing the apparatus, after 30 days, and after 90 days treatment. Orthodontic treatment, whether with clear aligners or fixed self-ligating brackets and light forces, increased AOPPs after the first 30 days of treatment. During the initial phases of orthodontic treatment, neither clear aligners nor fixed self-ligating brackets applying light forces showed changes in TAC and MPO. Orthodontic treatment with both clear aligners and fixed apparatus self-ligating brackets applying light forces increases oxidative stress (AOPPs) after the first 30 days of treatment. There are no differences in AOPP levels between treatment with clear aligners and self-ligating brackets during the first 90 days of treatment. The antioxidative capacity of saliva during the initial phases of orthodontic treatment, whether with self-ligating brackets or clear aligners, does not undergo significant changes. With either orthodontic technique, the patients’ salivary antioxidant capacity is similar.
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Affiliation(s)
- Cristina Menéndez López-Mateos
- Department of Stomatology IV, Faculty of Odontology, Complutense University, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain;
| | - María Luisa Menéndez López-Mateos
- Faculty of Dentistry, University of Granada, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain; (M.L.M.L.-M.); (A.A.-S.); (G.G.-M.)
| | - Antonio Aguilar-Salvatierra
- Faculty of Dentistry, University of Granada, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain; (M.L.M.L.-M.); (A.A.-S.); (G.G.-M.)
| | - Gerardo Gómez-Moreno
- Faculty of Dentistry, University of Granada, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain; (M.L.M.L.-M.); (A.A.-S.); (G.G.-M.)
| | | | - Hoda Khaldy
- Scientific Instrumentation Center, University of Granada, Paseo Professor Juan Osorio s/n, 18071 Granada, Spain;
| | - Mario Menéndez-Núñez
- Faculty of Dentistry, University of Granada, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain; (M.L.M.L.-M.); (A.A.-S.); (G.G.-M.)
- Correspondence:
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Alhendi A, Khounganian R, Ali R, Syed SA, Almudhi A. Structural Conformation Comparison of Different Clear Aligner Systems: An In Vitro Study. Dent J (Basel) 2022; 10:dj10050073. [PMID: 35621526 PMCID: PMC9139589 DOI: 10.3390/dj10050073] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/25/2022] [Accepted: 04/27/2022] [Indexed: 12/10/2022] Open
Abstract
The aim of this study was to evaluate the structural conformations of three clear aligner systems, Eon®, SureSmile®, and Clarity®, and compare them with the most commonly used system, Invisalign®. Clear aligner samples from Invisalign®, Eon®, SureSmile®, and Clarity® were cut into 5 × 5 mm squares and exposed to artificial saliva for 2 weeks. The specimens were then subjected to a Vickers hardness test by applying three separate indentations with a 25 gf load for 15 s. Hardness was calculated using the following formula: Vickers hardness number = 1.854 (F/D2). Fourier transform infrared spectroscopy (FTIR) analysis was performed, with a diamond hemisphere and infrared beam being allowed to pass through each specimen. A mid-infrared range from 4000 to 375 cm−1 was recorded. The samples were also evaluated using scanning electron microscopy (SEM) combined with energy-dispersive X-ray microanalysis spectroscopy at different magnifications. No statistically significant differences were observed between the included systems with regard to hardness. All systems showed a polyurethane-based material, as illustrated by the FTIR analysis. Some structural variations were noted in the Invisalign® system, which had a more homogeneous architecture. Statistically significant differences in the carbon weights were found among the systems. The four systems presented comparable hardness levels. Mild molecular composition differences were found, but all systems had the similarity of being composed of a polyurethane-based material. Carbon and oxygen were the main elements, as they were located in all studied clear aligners. The SEM analysis revealed that Invisalign® had a smoother surface than the other three systems. All included clear aligners had similar characteristics with minimal differences, providing a wide variety of options for clinical orthodontic treatment according to patients’ demands.
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Affiliation(s)
- Aseel Alhendi
- Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia;
- Correspondence: ; Tel.: +966-541-419-097
| | - Rita Khounganian
- Department of Oral Medicine and Diagnostic Sciences, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia;
| | - Raisuddin Ali
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia;
| | - Saeed Ali Syed
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia;
| | - Abdullazez Almudhi
- Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia;
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Force delivery modification of removable thermoplastic appliances using Hilliard precision thermopliers for tipping an upper central incisor. Clin Oral Investig 2022; 26:6105-6118. [PMID: 35641836 PMCID: PMC9525432 DOI: 10.1007/s00784-022-04560-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 05/20/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVES To evaluate the force delivered by removable thermoplastic appliances (RTAs, aligners), altered with Hilliard precision thermopliers, on an upper central incisor to tip it in the palatal and vestibular directions. MATERIALS AND METHODS A total of 10 aligners made from Ideal Clear® (polyethylene terephthalate glycol copolyester, PET-G) with a thickness of 1 mm were used in force analysis. Different-sized spot-thermoformed protuberances (bumps) were generated by activating the thermoplier (thin and thick) up to 30°, 60° and 90° in the centre of the palatal and vestibular surfaces of the aligner in 15° steps. The tipping (Fx) and intrusive (Fz) force components were measured on the isolated upper central incisor as part of a standardized resin model, with or without vertical loading by a weight equivalent. RESULTS Thermoplier activation at 30°, 60° and 90° resulted in different bump heights. The analysis revealed significantly higher Fx and Fz values with increasing bump heights for every activation step in all cases (p < 0.0001, respectively). Overall, the values of the Fx force component were higher than those observed for Fz. Significant differences between the palatal and vestibular tipping procedures were found depending on the resulting force components when the thin thermoplier was used; in contrast, the thick thermoplier resulted in a larger dispersion of the force magnitudes. CONCLUSIONS Aligners modified with Hilliard precision thermopliers showed altered biomechanical parameters. This approach could be an option for treatment modification. CLINICAL RELEVANCE The instrumental examination provided informative results for daily practice, as activation, force dosage and different force values under chewing pressure can be estimated more precisely based on the determined force levels.
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