In a study by Miller et al, with adults measuring pain in the first week of treatment.  Kevin Miller et al.  “A comparison of treatment impacts between Invisalign aligner and fixed appliance therapy during the first week of treatment.”  American Journal of Orthodontics and Dentofacial Orthopedics.  Volume 131, Issue 3, pp. 302. e1-302.e9, March 2007.

Gu, J et al. Evaluation  of Invisalign treatment effectiveness and efficiency compared with conventional fixed appliances using the Peer Assessment Rating index.   Am J Orthod Dentofacial Orthop February 2017;151:259-66 Buschang, P et al. Comparative time efficiency of aligner therapy and conventional edgewise braces. Angle Orthodontist, Vol 84, No 3, 2014

Compared to Invisalign aligners previously made from single-layer (EX30) material

Based on 2 week wear

* *Gu, J et al. Evaluation  of Invisalign treatment effectiveness and efficiency compared with conventional fixed appliances using the Peer Assessment Rating index.   Am J Orthod Dentofacial Orthop February 2017;151:259-66*Buschang, P et al. Comparative time efficiency of aligner therapy and conventional edgewise braces. Angle Orthodontist, Vol 84, No 3, 201