Mantovani E, et al. - Researchers assessed the fitting of 2 aligner systems, Invisalign and CA-Clear Aligner, using scanning electron microscopy (SEM). They analyzed the upper and lower central incisors, upper and lower first premolars, and upper and lower first molars. Comparable fit was exhibited by Invisalign and CA-Clear Aligner on anchorage teeth. At the gingival edges of aligners, better fit was provided by the Invisalign, whereas on the complex occlusal surfaces the CA-Clear Aligner provided better fit.