Objective: To use digital photographs to evaluate the attractiveness of Invisalign aligners (Align Technology, San Jose, CA, USA) with attachments that varied in number and shape compared with Sapphire brackets (Morelli, São Paulo, Brazil) and an aesthetic wire.
Materials and methods: Seven digital photographs of the same smile were obtained: six with Invisalign aligners with different numbers and shapes of attachments, and one with Sapphire brackets and an aesthetic wire. The images were shown at random to 180 evaluators divided into three groups composed of laypeople, clinical dental practitioners and orthodontists, respectively, who were asked to rate the attractiveness of each image on a visual analogue scale.
Results: The aligners with the fewest attachments were awarded the highest scores. Aligners with conventional attachments obtained higher scores than those with optimised attachments from all groups of evaluators; however, the difference between the shapes was statistically significant only for the aligner with six attachments in the group composed of laypeople.
Conclusions: The greater the number of attachments was, the lower the attractiveness score the aligners received. Conventional attachments were shown to be more attractive than optimised attachments. All three groups of evaluators considered the Sapphire brackets with aesthetic wire to be more attractive than the aligner with eight conventional attachments; thus, this number of attachments appears to be the aesthetic limit for Invisalign aligners.