Abstract: Method and apparatus for use in endodontic treatment include providing a one-way valve in the root canal system of a tooth undergoing endodontic therapy by which pressure which may build-up in the root canal system due to the production of purulence or gases from necrosing and/or infected tissue is vented from the root canal system and by which unobstructed drainage of the tooth is permitted, while at the same time food debris and foreign matter are prevented from entering and/or becoming packed within the root canal system thereby eliminating the possibility of the canal system becoming plugged and/or reducing introduction of bacteria into the root canal system. A method is disclosed for fitting a tooth with a one-way valve in a simple yet stable manner.

Abstract: An aseptic sheath for dental handpieces by the use of which the handpieces are eliminated as a possible source of transmission of microbial diseases. The sheath is formed of suitable resilient thermoplastic sheet material, preferably by vacuum forming, in a shape which corresponds to that of the particular handpiece with which it is to be used, e.g., to provide communicating spaces for substantially completely enclosing the head, neck and handle of a contra-angle handpiece. In use, the handpiece is inserted into the sheath by spreading normally overlapping edges of the sheath which extend longitudinally over at least the length of the handle-receiving portion to provide access for the handpiece to the sheath interior. After insertion is completed,the edges are released to snap back over the handpiece due to the resiliency of the sheath-forming material to substantially completely enclose the handpiece therewithin.