Cannula and process

• US 4,276,880 A
• Filed: 12/14/1979
• Issued: 07/07/1981
• Est. Priority Date: 09/14/1978
• Status: Expired due to Term

• Current Assignee: Hills Family Preservation Trust
• Original Assignee: Oscar Malmin
• Inventors: Malmin, Oscar
• Primary Examiner(s): YASKO JR, JOHN D
• Application Number:
  US06/103,935
• Time in Patent Office: 571 Days
• Field of Search: 128/221, 128/218 N, 128/240, 128/272, 128/276, 128/347, 32/40 R, 32/57
• US Class Current: 604/28
• CPC Class Codes: A61C 17/0202 Hand-pieces
• CPC Class Codes: A61C 17/0208 combined with means providing suction A61C17/0211 takes precedence
• CPC Class Codes: 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

Abstract

An improved cannula for utilization with and attachment to a dental instrument capable of selectively and alternatively injecting liquid under pressure and providing a vacuum for aspirating purposes and a process for utilizing the cannula. The improved cannula has a through central bore opening into the first end of the cannula body and has a second end that is either open to said bore or closed. Opposed slots or openings are provided in the cannula body adjacent the second end of the cannula and provide communication between the exterior of the cannula and the central bore, and also means for attaching the cannula to an instrument such as described above are provided on the body thereof. A modified form of the invention has a fully closed second end and a single elongate radiused "window" opening closely adjacent the closed end.

Claims

1. A cannula for attachment to and use with an instrument capable of selectively supplying fluid under pressure and a suction force, comprising:

(A) an elongate, cylindrical, rigid body having a central, longitudinally extending bore and having first and second ends;

(B) said central bore opening into said first end of said body;

(C) said second end of said body being closed smooth, and rounded;

(D) said body being imperforate throughout substantially its entire length;

(E) said body having only one elongate opening in its wall with one end thereof being disposed in close adjacency with said closed end; and

(F) attachment means carried by said first end for releasable engagement with said instrument.

2. The cannula of claim 1 wherein said elongate opening has a depth substantially equal to one-half the diameter of said body.

3. The cannula of claim 2 wherein said elongate opening has

(A) opposed end walls;

and

(B) opposed bottom walls;

(C) said end walls merging into said bottom walls with the area of such merger being radiused.

4. The cannula of claim 3, where said bottom walls taper inwardly and downwardly from the peripheral wall of said body toward the interior thereof.

5. The cannula of claim 1 wherein said closed second end of said body tapers from the outer diameter of said body to a lesser diameter at its ultimate end.

6. The cannula of claim 5 wherein the lesser diameter portion of said second end is symmetrical with the center line of said body.

7. The cannula of claim 1 wherein said one end of said elongate opening is disposed approximately one millimeter (1 mm) from said second closed end of said body.

8. The cannula of claim 3, wherein said opening has a length of from approximately one millimeter (1 mm) to approximately one and one-quarter millimeter (1.25 mm) at its point of opening into the periphery of said body to from approximately three-quarter millimeter (0.75 mm) to one millimeter (1 mm) at its bottom.

9. The cannula of claim 1, wherein said closed second end is conical.

13. The cannula of claim 1 wherein a press fit plug is received within said central bore in said second end of said body.

14. The cannula of claim 1 wherein said second end of said cannula is swedged closed to seal off said central bore.

10. An endodontic treatment process using an irrigating-aspirating syringe to which is attached a rigid, elongate, cylindrical cannula having a longitudinal bore opening into the first end thereof, a smooth, rounded centrically-aligned fully closed second end and a substantially imperforate length dimension possessing, near its second end, at least one longitudinally extending opening radius cut to a depth of one-half the diameter of said member with said opening having proximal and distal radiused cut ends with said distal end of said window-like opening being located approximately one millimeter (1 mm) from the tip of said closed second end of said cannula, said process comprising the steps of:

(A) making a root canal preparation by enlarging the root canal through reaming, filing or milling thereby removing portions of pulpal tissue and dentin;

(B) inserting the second end of the cannula to the full depth of said preparation of channel thereby sealing off the apical foramen;

(C) irrigating the fullest apical depths of said preparation with liquids and chemical solutions under pressure which exit said opening in a turbulent, churning, action the thereby mechanically scrubbing said fullest apical depths while simultaneously exerting a chemical cleansing action while said second end seals said apical foramen preventing said liquids, solutions, or debris exiting freely from the depths of said preparation;

(D) aspirating said fullest apical depths of said preparation by supplying suction to said opening with said negative pressure drawing said liquids, solutions or debris directly or indirectly over the surfaces of said second end into said opening for removal from said deepest apical areas of said preparation while said second end seals said apical foramen to prevent aspirating of said periapical tissues through said apical foramen;

(E) alternating said irrigation step and said aspirating step while keeping said second end fully seated over said apical foramen; and

(F) finishing said cleansing actions by drying said fullest apical depths of said preparation using the aspirating step as the final step while said second end of said cannula is fully seated over said apical foramen.

11. The process of claim 10 further characterized by the steps of injecting root canal filling materials through said opening in said cannula and withdrawing the cannula from the root canal as the canal fills from the apical end outward.

12. A periodontic treatment process using an irrigating-aspirating syringe to which is attached a rigid, elongate, cylindrical cannula having a longitudinal bore opening into the first end thereof, a smooth, rounded centrically-aligned fully closed second end and a substantially imperforate length dimension possessing near its second end at least one longitudinally extending opening radius cut to a depth of one-half the diameter of said member with said opening having proximal and distal radiused cut ends with said distal end of said window-like opening being located approximately one millimeter (1 mm) from the tip of said closed second end of said cannula, said process comprising the steps of:

(A) inserting said second end of said cannula into the sulcus to the fullest depth thereof;

(B) irrigating the sulcus by injecting liquids and chemical solutions under pressure through said opening;

(C) aspirating the sulcus by supplying suction to remove the liquids and chemical solutions and debris through said opening;

(D) repeating steps B and C until the sulcus is cleansed and debrided.