Abstract: A reshapable retention device for insertion at a dental site and contact with adjacent dental surfaces, for the controlled delivery to the dental site of at least one material having a predetermined intraoral activity. The retention device comprises at least one matrix containing the material. The retention device is adapted for physically affixing at the dental site for at least a predetermined time period correlated to the delivery of a predetermined portion of the at least one matrix to the dental site in a controlled single, bi or multiphase pattern. The retention device comprises a first configuration in which the overall dimensions of the retention device are larger than at least one dimension of the dental site. The first configuration is reshapable to a second configuration in which at least one dimension of the retention device is reduced to enable physically affixing the retention device at the dental site.