Abstract: An improved elastic orthodontic member and treatment method for preventing and treating certain dental diseases often associated with or increased by normal orthodontic treatment. The orthodontic member is an orally-acceptable elastic polymeric material having a dentally-active pharmacological agent uniform throughout the polymeric material as an in situ constituent of polymeric-member formation from a homogeneous mixture of polymeric material and pharmacological agent. Without compromising orthodontic force-applying elasticity, the orthodontic member provides release of pharmacological agent in an intraoral environment in therapeutically-acceptable concentrations over an extended period which is substantially commensurate with the useful life of force-applying elasticity of said orthodontic member.