Precision in attachments
Soon after the mass adoption of clear aligners, it became apparent that a plastic shell did not provide sufficient purchase on the teeth for all movements. Attachments, or polymerised bumps of composite directly bonded to the teeth, were developed to provide a grip for these movements. Presumably, attachments provide better engagement between the teeth and aligner. A technique for producing these attachments was developed in which a mould of the dental arch, or template, is used to form attachments directly on the teeth (Fig. 1). It is typically accomplished by injecting a small amount of composite into each of the attachment pockets in the template. This method enabled a great deal of customisation because many sizes and shapes of attachment may be produced, and there is wide choice regarding their position and orientation.