Plastic Orthodontic Appliance Having Mechanical Bonding Base And Method Of Making Same

Patent Publication Number: US 6190165 B1

Title: Plastic orthodontic appliance having mechanical bonding base and method of making same

Filing Date: March 23, 1999

Priority Date: March 23, 1999

Inventor(s): Craig A. Andreiko, Thomas V. Selkee

Original Assignee / Applicant(s): Ormco Corporation

Link to Patent: US6190165B1

Summary:

This invention discloses a method of forming an orthodontic appliance having projecting structure extending from an appliance base which is adapted to mechanically bond to a tooth surface with an adhesive. It is disclosed that undercuts are formed on the projecting structure of the orthodontic appliance this invention by directing beads of glass in an air stream perpendicularly toward the base of the appliance, against the end surfaces of the outer extremities or tips of the projecting structure. It is acknowledged that the beads needed to impinge upon the surfaces with a momentum or velocity such as to produce a pressure that provides the optimal deformation. The pressure applied by the beads on the said surfaces was ascertained with the help of Fujifilm Prescale® by affixing the Fujifilm Prescale® film on one or more of the said surfaces. When the beads impinge upon the Fujifilm Prescale® film, a color is formed on the film. Through color charts matching the color intensity to the corresponding pressure values, the pressure applied on the surface is ascertained.