Micro computed tomography evaluation of Invisalign aligner thickness homogeneity

Edoardo Mantovani; Simone Parrini; Emanuele Coda; Giovanni Cugliari; Nicola Scotti; Damiano Pasqualini; Andrea Deregibus; Tommaso Castroflorio

doi:10.2319/040820-265.1

journal article Jan 21, 2021

Micro computed tomography evaluation of Invisalign aligner thickness homogeneity

Edoardo Mantovani Simone Parrini Emanuele Coda Giovanni Cugliari Nicola Scotti

Damiano Pasqualini

Andrea Deregibus Tommaso Castroflorio

The Angle Orthodontist Vol. 91 No. 3 pp. 343-348 · The Angle Orthodontist (EH Angle Education & Research Foundation)

View at Publisher Save 10.2319/040820-265.1

Abstract

ABSTRACT

Objectives
To measure the thickness homogeneity of Invisalign (Align Technology Inc, San José, Calif) aligners with micro-computed tomography (micro-CT) scans.

Materials and Methods
Starting from micro-CT scanning of 20 different aligners, multiplanar reconstructions were obtained. An orthodontist blinded about the study measured aligner thickness in different regions (molar, canine, incisor) and in different sites (gingival–buccal, buccal, occlusal, lingual, and gingival–lingual). To assess various thicknesses in different aligner sites and regions, the sample was stratified into subgroups and linear regression analysis was performed.

Results
Descriptive analysis showed that mean thickness of aligners in the incisor region ranged from 0.582 mm to 0.639 mm, in the canine region from 0.569 mm to 0.644 mm, and in the molar region from 0.566 mm to 0.634 mm. Student's t-tests showed no significant differences in the aligner thickness of different regions when data were stratified by different sites. Student's t-tests showed significant differences in thickness homogeneity for the molar region when the data were stratified by tooth (mean difference = 0.068 mm; 95% confidence interval, 0.009–0.126 mm; P = .024).

Conclusions
Invisalign aligner thickness is characterized by small differences. The only significant difference was revealed in the molar region where thickness of the gingival–lingual edge is significantly thinner than that measured at the occlusal aspect. From a clinical perspective, the results of the present study could be considered to explain the reduced predictability of several orthodontic tooth movements in the molar region.

Topics

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Metrics

32

Citations

36

References

Details

Published: Jan 21, 2021
Vol/Issue: 91(3)
Pages: 343-348

Authors

E

Edoardo Mantovani

Resident, Department of Orthodontics, Dental School, University of Turin, Turin, Italy

Research Fellow, Department of Medical Sciences, University of Turin, Turin, Italy

Endodontics and Restorative Dentistry, CIR Dental School, Department of Surgical Sciences, University of Turin, 10126 Turin, Italy

A

Andrea Deregibus

Professor and Department Chairman, Department of Orthodontics, Dental School, University of Turin, Turin, Italy

T

Tommaso Castroflorio

Cite This Article

Edoardo Mantovani, Simone Parrini, Emanuele Coda, et al. (2021). Micro computed tomography evaluation of Invisalign aligner thickness homogeneity. The Angle Orthodontist, 91(3), 343-348. https://doi.org/10.2319/040820-265.1

Micro computed tomography evaluation of Invisalign aligner thickness homogeneity

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