Invisalign® vs. Spark™ template: Which is the most effective in the attachment bonding procedure? a randomized controlled trial

Aim: The primary aim of this randomized clinical trial was to evaluate the percentage of attachments’ debonding at the template’s removal both in Invisalign® and Spark™ systems. The secondary aim was to define the percentage of patients who did not show attachments’ debonding at the template’s removal. Materials and methods: Eighty patients who needed an orthodontic treatment were included in the study and randomly assigned to a treatment to be performed with Spark™ or Invisalign® clear aligners system. The patients were equally divided into two groups: Spark group (n = 40) and Invisalign group (n = 40). At the template removal by the teeth surface after the attachment bonding procedure, in each patient of both groups, it was assessed if some attachment debonding occurred and the number of attachments detached. Results: The Spark group showed, in general, a lower frequency in debonding in comparison with the Invisalign group, as 87.5% of patients in the Spark group did not show any bonding failure versus 27.5% in those of the Invisalign group. Conclusions: At template removal, the Spark™ template showed less attachment debonding compared to the Invisalign® template. The Spark™ template can be considered more effective in attachments’ transferring to the tooth surface than the Invisalign® one.