Effect of oral exposure on chemical, physical, mechanical, and morphologic properties of clear orthodontic aligners
Am. j. orthod. dentofacial orthop
; 164(2): 51-63, Aug. 2023. ilus
Article
in English
| BBO - Dentistry
| ID: biblio-1532238
Responsible library:
BR926.1
ABSTRACT
The dental industry is heavily committed to developing more esthetic solutions for orthodontic treatments. Invisalign is a system of transparent orthodontic aligners introduced as an alternative to conventional orthodontic fittings with brackets and metal wires. This study aimed to assess the chemical, physical, mechanical and morphologic changes in these polymeric aligners after exposure to the oral environment. Twenty-four Invisalign orthodontic aligners were equally divided into 2 groups an in vivo aged group in which patients used aligners for 14 days and the reference group, unexposed to the oral environment. Different experimental techniques were used to study the chemical structure, the color changes and translucency, the density and subsequent volume of the aligners, mechanical properties, surface roughness, morphology and elemental composition. The data were subjected to several statistical analyses. Clear orthodontic aligners exhibit chemical stability but undergo a statistically significant optical change in color and translucency. There was a gradual increase in the water absorption rate and the dimensional variation of the polymer, indicating a strong correlation among these factors. The mechanical properties of the polymer showed a statistically significant decrease in its elastic modulus and hardness. There was a slight tendency toward increased surface roughness of the material, but no statistical differences were found between reference and aged groups. The surface morphology of the used aligners demonstrates microcracks, distortions and biofilm formation. Intraoral aging adversely affected the physical, mechanical, and morphologic properties of the Invisalign appliance.
Subject(s)
Full text:
Available
Collection:
National databases
Database:
BBO - Dentistry
Main subject:
Orthodontic Appliances, Removable
/
Polyurethanes
/
Dental Research
/
Morphological and Microscopic Findings
/
Mouth Mucosa
Limits:
Humans
Language:
English
Journal:
Am. j. orthod. dentofacial orthop
Year:
2023
Document type:
Article
Institution/Affiliation country:
Federal Fluminense University/BR
/
Federal University of Rio de Janeiro/BR
/
Federal University of Rio de Janeiro,/BR