Effect of different attachment geometries on the mechanical load exerted by PET‑G aligners during derotation of mandibular canines

Elkholy, Fayez; Mikhaiel, Bishoy; Repky, Stefan; Schmidt, Falko; Lapatki, Bernd G.

doi:10.1007/s00056-019-00193-7

Cited by 22 publications

(15 citation statements)

References 11 publications

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“…The preservation and geometries influence tooth movement, especially with rotations and root control. 3,4 Because attachments are crucial mechanical components, attachment damage may sometimes cause the tooth to not track properly, which may affect treatment results.…”

Section: Introductionmentioning

confidence: 99%

Assessment of preparation time and 1-year Invisalign aligner attachment survival using flowable and packable composites:

Lin¹,

Li-min²,

Li³

et al. 2021

The Angle Orthodontist

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Objectives To compare preparation time and 1-year Invisalign aligner attachment survival between a flowable composite (FC) and a packable composite (PC). Materials and Methods Fifty-five participants (13 men and 42 women, mean age ± SD: 24.2 ± 5.9 years) were included in the study. Ipsilateral quadrants (ie, maxillary and mandibular right, or vice versa) of attachments were randomly assigned to the FC group (Filtek Z350XT Flowable Restorative) and the PC group (Filtek Z350XT Universal Restorative) by tossing a coin. The primary outcome was preparation time. The secondary outcome was time to the first damage of an attachment. Preparation times were compared using the paired t-test, and the survival data were analyzed by the Cox proportional hazards model with a shared frailty term, with α = .05. Results The preparation times were significantly shorter with the FC (6.22 ± 0.22 seconds per attachment) than with the PC (32.83 ± 2.16 seconds per attachment; P < .001). The attachment damage rates were 14.79% for the FC and 9.70% for the PC. According to the Cox models, attachment damage was not significantly affected by the attachment material, sex, arch, tooth location, attachment type, presence of overbite, or occurrence of tooth extraction. Conclusions The use of a FC may save time as compared with the use of a PC. With regard to attachment survival, there was no significant difference between the two composites. None of the covariates of attachment materials (sex, arch, tooth location, attachment type, presence of overbite, oir occurrence of tooth extraction) affected attachment damage.

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Section: Introductionmentioning

confidence: 99%

Assessment of preparation time and 1-year Invisalign aligner attachment survival using flowable and packable composites:

Lin¹,

Li-min²,

Li³

et al. 2021

The Angle Orthodontist

View full text Add to dashboard Cite

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“…Research in the field of prognosis and accuracy of prediction of the desired tooth movement has resulted in a small but not insignificant group of primary studies, with the majority being conducted in the last 3-4 years (Charalampakis et al, 2018;Haouili et al, 2020;Lombardo et al, 2017). In-house simulation software has been developed and utilised by companies in an attempt to provide visualisation of treatment outcome, following a range of individually planned tooth movement increments (Elkholy et al, 2019;Krieger et al, 2012;Simon et al, 2014). In this respect, prediction of anticipated tooth movements is constantly used by the companies of aligner providers in order to estimate the sequential change of aligners during treatment.…”

Section: Prior Research and Implications For Practicementioning

confidence: 99%

Predictability of rotational tooth movement with orthodontic aligners comparing software-based and achieved data: A systematic review and meta-analysis of observational studies

2021

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Objective: To evaluate all available evidence on the prediction of rotational tooth movements with aligners. Data sources: Seven databases of published and unpublished literature were searched up to 4 August 2020 for eligible studies. Data selection: Studies were deemed eligible if they included evaluation of rotational tooth movement with any type of aligner, through the comparison of software-based and actually achieved data after patient treatment. Data extraction and data synthesis: Data extraction was done independently and in duplicate and risk of bias assessment was performed with the use of the QUADAS-2 tool. Random effects meta-analyses with effect sizes and their 95% confidence intervals (CIs) were performed and the quality of the evidence was assessed through GRADE. Results: Seven articles were included in the qualitative synthesis, of which three contributed to meta-analyses. Overall results revealed a non-accurate prediction of the outcome for the software-based data, irrespective of the use of attachments or interproximal enamel reduction (IPR). Maxillary canines demonstrated the lowest percentage accuracy for rotational tooth movement (three studies: effect size = 47.9%; 95% CI = 27.2–69.5; P < 0.001), although high levels of heterogeneity were identified (I2: 86.9%; P < 0.001). Contrary, mandibular incisors presented the highest percentage accuracy for predicted rotational movement (two studies: effect size = 70.7%; 95% CI = 58.9–82.5; P < 0.001; I2: 0.0%; P = 0.48). Risk of bias was unclear to low overall, while quality of the evidence ranged from low to moderate. Conclusion: Allowing for all identified caveats, prediction of rotational tooth movements with aligner treatment does not appear accurate, especially for canines. Careful selection of patients and malocclusions for aligner treatment decisions remain challenging.

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“…Clear aligners are not only appliances but also a technique. Therefore, knowledge of biomechanics is required to measure force-to-moment components that the aligner exerts on a single tooth [ 23 ]. There is a slight mismatch between tooth and aligner capable of generating a system of forces that starts the biological process of orthodontic movement [ 5 , 10 , 15 , 16 , 24 ].…”

Section: Introductionmentioning

confidence: 99%

“…There is a slight mismatch between tooth and aligner capable of generating a system of forces that starts the biological process of orthodontic movement [ 5 , 10 , 15 , 16 , 24 ]. The technique success depends on the contact areas between tooth and material, determined by tooth size and morphology [ 23 ], type and amount of movement desired, the internal surface of the aligner [ 24 ], the material properties (thickness, stiffness, and elastic modulus), and its fitting with the tooth [ 5 – 7 , 10 , 11 , 13 , 16 ]. In the scientific literature, there is a consensus on the dental movements that an aligner generates with predictability, like alignment and levelling of arches in mild and moderate crowding [ 6 , 9 , 15 , 18 , 25 , 26 ], and endoinclination of teeth, especially of lower incisors [ 7 , 9 , 27 ].…”

Section: Introductionmentioning

confidence: 99%

Performance of Rigid and Soft Transfer Templates Using Viscous and Fluid Resin-Based Composites in the Attachment Bonding Process of Clear Aligners

Valeri

Aloisio

Mummolo

et al. 2022

International Journal of Dentistry

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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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Effect of different attachment geometries on the mechanical load exerted by PET‑G aligners during derotation of mandibular canines

Cited by 22 publications

References 11 publications

Assessment of preparation time and 1-year Invisalign aligner attachment survival using flowable and packable composites:

Assessment of preparation time and 1-year Invisalign aligner attachment survival using flowable and packable composites:

Predictability of rotational tooth movement with orthodontic aligners comparing software-based and achieved data: A systematic review and meta-analysis of observational studies

Performance of Rigid and Soft Transfer Templates Using Viscous and Fluid Resin-Based Composites in the Attachment Bonding Process of Clear Aligners

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