6
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Changes in Roughness and Mechanical Properties of Invisalign ® Appliances after One- and Two-Weeks Use

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          The aim of this study was to estimate the possible changes of surface roughness and the mechanical properties of Invisalign ® appliances over one- and two-week of service. Forty appliances with attachments were retrieved after the end of orthodontic treatment from different patients. Half of them had been used for one week (1W), and the rest for two weeks (2W). Ten unused Invisalign ® appliances were used as the control (CON). An equal number of teeth possessing attachments were cut of aligners deriving from all groups (1W, 2W, and CON), and the Sa, Sq, Sz, Sc, and Sv roughness parameters of the internal surface of the aligner attachment area and the opposite lingual side (which was in contact to enamel) were determined by optical profilometry. Then, ten first molars originating from all groups were embedded in acrylic resin, and were ground and polished. Instrumented indentation testing (IIT) was performed in order to determine the Martens hardness (HM), indentation modulus (E IT), and relaxation index (R IT), according to ISO 14577-2002. The produced data were statistically processed by one- or two-way analysis of variance (ANOVA) and multiple comparison post-hoc tests (a = 0.05). Both the surface roughness and mechanical properties of the retrieved groups (1W and 2W) showed statistically significant differences compared with CON, but without statistically significant differences between each other. The roughness variables of the as-received material were shown to be reduced after intraoral service demonstrating a wear effect. Ageing has a detrimental effect on the surface roughness and mechanical properties of Invisalign ® appliances, although this effect is restricted to the first week of clinical usage.

          Related collections

          Most cited references25

          • Record: found
          • Abstract: found
          • Article: not found

          Efficacy of clear aligners in controlling orthodontic tooth movement: a systematic review.

          To assess the scientific evidence related to the efficacy of clear aligner treatment (CAT) in controlling orthodontic tooth movement.
            Bookmark
            • Record: found
            • Abstract: not found
            • Article: not found

            Stress–strain behavior of thermoplastic polyurethanes

              Bookmark
              • Record: found
              • Abstract: found
              • Article: found
              Is Open Access

              Clinical effectiveness of Invisalign® orthodontic treatment: a systematic review

              Background Aim was to systematically search the literature and assess the available evidence regarding the clinical effectiveness of the Invisalign® system. Methods Electronic database searches of published and unpublished literature were performed. The reference lists of all eligible articles were examined for additional studies. Reporting of this review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results Three RCTs, 8 prospective, and 11 retrospective studies were included. In general, the level of evidence was moderate and the risk of bias ranged from low to high, given the low risk of bias in included RCTs and the moderate (n = 13) or high (n = 6) risk of the other studies. The lack of standardized protocols and the high amount of clinical and methodological heterogeneity across the studies precluded a valid interpretation of the actual results through pooled estimates. However, there was substantial consistency among studies that the Invisalign® system is a viable alternative to conventional orthodontic therapy in the correction of mild to moderate malocclusions in non-growing patients that do not require extraction. Moreover, Invisalign® aligners can predictably level, tip, and derotate teeth (except for cuspids and premolars). On the other hand, limited efficacy was identified in arch expansion through bodily tooth movement, extraction space closure, corrections of occlusal contacts, and larger antero-posterior and vertical discrepancies. Conclusions Although this review included a considerable number of studies, no clear clinical recommendations can be made, based on solid scientific evidence, apart from non-extraction treatment of mild to moderate malocclusions in non-growing patients. Results should be interpreted with caution due to the high heterogeneity. Electronic supplementary material The online version of this article (10.1186/s40510-018-0235-z) contains supplementary material, which is available to authorized users.
                Bookmark

                Author and article information

                Journal
                Materials (Basel)
                Materials (Basel)
                materials
                Materials
                MDPI
                1996-1944
                28 July 2019
                August 2019
                : 12
                : 15
                : 2406
                Affiliations
                [1 ]Department of Orthodontics, University of Sydney Dental School, Sydney, NSW 2010, Australia
                [2 ]Clinic of Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, 8032 Zurich, Switzerland
                [3 ]Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, 11527 Athens, Greece
                Author notes
                Author information
                https://orcid.org/0000-0001-9188-7839
                Article
                materials-12-02406
                10.3390/ma12152406
                6696190
                31357697
                a7a0b2d9-c401-4c83-902a-e7cb0de0745c
                © 2019 by the authors.

                Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( http://creativecommons.org/licenses/by/4.0/).

                History
                : 16 July 2019
                : 26 July 2019
                Categories
                Article

                invisalign®,orthodontic appliances,mechanical properties,relaxation,instrumented indentation testing

                Comments

                Comment on this article