Braces are prepared from metal or porcelain which are affixed to your teeth. They make use metal wires and rubber bands to help teeth move in right direction. Aligners are prepared from plastic and are customised to suit your teeth. The tooth-coloured filling material are attached to certain teeth so as to enable the aligner, grip the tooth, to move correctly. Aligners can be administered for most of the dental problems but not all orthodontic problems. Therefore, it is better to consult your orthodontist to get clarity on which option serves you best.