# US 4,400,160 A · Atraumatic endodontic reconstruction system and process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,400,160 A - Document ID: US4400160A - Status: Granted - Kind: A - Application number: 06/318,935 - Filed: 1981-11-06 - Granted: 1983-08-23 - Earliest claimed: 1981-11-06 - Assignees: Leopold Paul Lustig - Inventors: Leopold P. Lustig; Alfred H. Rosen - Web page: https://patentgrep.com/patent/US4400160A ## CPC - A61C 13/30: Fastening of peg-teeth in the mouth - A61C 5/40: Implements for surgical treatment of the roots or nerves of the teeth; Nerve needles; Methods or instruments for medication of the roots - A61C: DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE (non-driven toothbrushes A46B; {tongue scrapers A61B17/24;} preparations for dentistry A61K6/00; preparations for cleaning the teeth or mouth A61K8/00, A61Q11/00) ## Abstract The invention achieves its purposes with a grommet thimble incorporating a bore sleeve which may be fitted with retainer means for a sanitary dam. When this thimble is fitted into the specially-prepared entrance portion of a root canal, the retainer means extends from the tooth for holding a dam of rubber or the like without injury to surrounding gingiva during placement of a clamp for the rubber dam. The root canal can be prepared with the sleeve and dam in place, the sleeve and dam serving to facilitate the establishment and maintenance of a sterile field of operation without creation of unnecessary lacerations on the surrounding gingiva. After completion of the desired preparation procedure, or of partial completion, a temporary plug can be removably fitted into the sleeve protection of the work done or in process. For completion of a restoration several options are available. The retainer means can be left in place and used to anchor a core with or without a post. Alternatively a post can be fastened (e.g. screwed) into the sleeve, with or without keeping the retainer means. ## Claims ### Claim 1 A grommet thimble for use in preparing a root canal of a tooth for endodontic reconstruction of said tooth comprising a tubular body of solid material having an outer diameter greater than the diameter of said root canal and an axial length which is a small fraction of the depth of said root canal for fitting into and lining an entrance hole of larger bore than the root canal in the entrance portion of the canal, said tubular body having an inner bore the diameter of which is substantially the same as the inner diameter of said canal giving access to said canal for purposes including preparation and reconstruction, including flanged-collar means at the periphery of the end which remains outside said entrance hole when said thimble is installed therein, said flanged collar means overlying an annular recess which is open for receiving and for retaining in said recess a sanitary dam having a perforation in register with said inner bore, so as to cover said tooth and the surrounding gingiva with said dam while giving access to said root canal through said perforation and said bore, and, clamp means engageable under said collar for holding said sanitary dam in a desired location. ### Claim 2 (depends on 1) A grommet thimble according to claim 1 having screw-threads on its outer tubular surface, for threadedly fixing said thimble in said entrance hole. ### Claim 3 (depends on 2) A grommet thimble according to claim 2 having a substantially smooth inner bore. ### Claim 4 (depends on 2) A grommet thimble according to claim 2 having a screw-threaded inner bore. ### Claim 5 (depends on 2) A grommet thimble according to claim 2 having a roughened surface on its inner bore. ### Claim 6 (depends on 1) A grommet thimble according to claim 1 including a separable collar threadedly engageable inside said inner bore at said end, for fitting through said perforation of said dam and, when threaded into said bore, retaining said dam with said perforation in register with said bore. ### Claim 7 (depends on 1) For use in the combination according to claims 1 a clamp in the form of a wire loop, and means to alter the size of said loop from a size capable of fitting over said collar to a fixable size tightly embracing said retaining means under said collar. ### Claim 8 In combination, a grommet thimble for use in preparing a root canal of a tooth for endodontic reconstruction of said tooth, and a reconstruction pin adapted to be installed in said root canal, said grommet thimble comprising a tubular body of solid material having an outer diameter greater than the diameter of said root canal and an axial length which is a minor fraction of the depth of said root canal for fitting into and lining an entrance hole of larger bore than the root canal in the entrance portion of the canal and giving support to the dentinal material surrounding said entrance hole, said tubular body having an inner bore the diameter of which is substantially the same as the inner diameter of said canal giving access to said canal through said inner bore, said reconstruction pin having a support portion adapted to fit mating-wise into said inner bore for supporting said reconstruction pin in said grommet thimble, means to support an extra-coronal reconstruction, and a canal portion extending from said support portion for penetrating a prepared root canal to a prescribed depth measured from said grommet thimble. ### Claim 9 (depends on 8) A combination according to claim 8 in which said grommet thimble has a screw-threaded inner bore, and said reconstruction pin has corresponding screw threads on the outer periphery of its support portion, for engaging said reconstruction pin in said grommet thimble with capability to adjust the penetration into said canal of said canal portion of said reconstruction pin. ### Claim 10 (depends on 8) A combination according to claim 8 in which said canal portion of said reconstruction pin has means at its apical end for engaging in the bottom of said prepared root canal. ### Claim 11 (depends on 10) A combination according to claim 10 in which said apical end is threaded. ### Claim 12 (depends on 11) A combination according to claim 11 in which said support portion is free of engagement means and fits slidingly within said inner bore of said tubular body. ### Claim 13 (depends on 8) A combination according to claim 8 in which at least said canal portions of said reconstruction pin is axially hollow. ### Claim 14 (depends on 8) A combination according to claim 8 in which said pin is adapted to conduct light in the range including at least the visible and ultra-violet frequency bands. ### Claim 15 Method of preparing a root canal of a tooth for endodontic reconstruction of said tooth comprising the steps of opening a hole of larger bore than the root canal in an entrance portion of the canal, lining said hole with a grommet thimble, fitting said grommet thimble with a sanitary dam covering said tooth and the surrounding gingiva, providing an opening into said grommet thimble through said flexible dam, and preparing said canal through said opening and said grommet thimble.