1. Orthodontic material applications over the past century: Evolution of research methods to address clinical queries 
Theodore Eliades 
American Journal of Orthodontics and Dentofacial Orthopedics 
Volume 147, Issue 5, Pages S224-S231 (May 2015)
DOI: /j.ajodo
Copyright © 2015 American Association of Orthodontists Terms and Conditions

2. Fig 1
Various methodologies are used to assess roughness. This is a graph of the profilometry with a stylus method demonstrating the problems in assessing the actual variations of peaks and valleys on a surface, establishing the limiting factor of stylus size.
American Journal of Orthodontics and Dentofacial Orthopedics  , S224-S231DOI: ( /j.ajodo )
Copyright © 2015 American Association of Orthodontists Terms and Conditions

3. Fig 2
Representative 3-dimensional optical profilometric images of tested groups. IE, Intact enamel; AE, acid etched enamel
(adapted from Patcas et al5).
American Journal of Orthodontics and Dentofacial Orthopedics  , S224-S231DOI: ( /j.ajodo )
Copyright © 2015 American Association of Orthodontists Terms and Conditions

4. Fig 3
Atomic force microscopic image depicting the high resolution (nanoscale range) of the method.
American Journal of Orthodontics and Dentofacial Orthopedics  , S224-S231DOI: ( /j.ajodo )
Copyright © 2015 American Association of Orthodontists Terms and Conditions

5. American Journal of Orthodontics and Dentofacial Orthopedics  , S224-S231DOI: ( /j.ajodo )
Copyright © 2015 American Association of Orthodontists Terms and Conditions