Patent ID: 8808002

Claim:
A method for filling and sealing at least the apical end of a prepared root canal, the method comprising: (a) receiving a signal from an apex locating circuit; the apex locating circuit comprising a thermoplastic filler material delivery device removably received in a holder and having a bed portion; the apex locating circuit generating the signal when a distal end of the bed portion is within a predetermined distance of the apical end of a root canal; the delivery device comprising: (i) a shaft having the bed portion at a distal end thereof; said bed portion having an inner surface and an outer surface opposite said inner surface; an electrically conductive portion extending along at least the outer surface of said delivery device bed portion which will contact a surface of the root canal when the device is inserted in the root canal; said inner surface of said bed portion defining a filler material receiving surface; said bed portion being generally arcuate in shape and wherein said inner surface is concave and said outer surface is convex; (ii) a plug of a biocompatible thermoplastic filler material mounted to the inner surface of said bed portion such that the outer surface of said bed portion is substantially free of filler material such that said outer surface of said bed portion can contact a surface of the root canal at least at a distal end of the bed portion; said plug of filler material comprising an upper surface, a side surface, and a distal end; the bed portion of the shaft wrapping at least partially around the side surface of the plug of filler material and contacting the plug of filler material substantially along the length of the side surface of the plug of filler material from the upper end of the plug of filler material to at or proximate the distal end of the plug of filler material whereby said shaft extends up from an edge of said upper surface of said plug of filler material; the delivery device bed portion having a greater thermal conductivity than the filler material; and (b) automatically activating a heating device of the holder in response to the signal from the apex locating circuit electronically confirming that the filler material is within a predetermined distance of the apical end of the root canal; the heating device being in thermal communication with said bed portion of said delivery device; said heating device heating the plug of filler material from the side surface of the plug of filler material and along substantially the full length of the plug of filler material to a moldable temperature.