Patent attributes
Methods of forming dental tooth positioning appliances. Methods may include identifying a portion of a first digital model corresponding to a portion of the dentition for chemical treatment. Methods may also include forming a second digital model with a scaled up cavity by scaling up a size of a tooth of the first digital model. Methods may further include forming a polymeric shell including a scaled up cavity having dimensions that are proportional to a corresponding surface of the second digital model. The polymeric shell may further include one or more spacers that protrude from an inner surface of the scaled up cavity. The spacer(s) may be arranged to maintain a uniform space between the polymeric shell and the portion of the dentition identified for chemical treatment, and for holding a chemical for treating the identified portion of the dentition.