United States Patent 3816921

A multi-purpose instrument with accessory or servicing tools having the capabilities of irrigating, evacuating, and sealing the root canal of a tooth. The instrument is designed to be operated by one hand and includes a handle and a finger grip portion, as well as a body portion integral with the handle. Internally the body has a series of three decreasing diameter coaxial bores, with the largest of the bores being designed to receive a disposable medicator dental ampule, carpule or syringe. The second bore is designed to receive a spring-loaded valve, while the third bore opens from the opposed end of the instrument and is designed to receive a conventional needle. Disposed on the body is an access port which can be connected to a suitable vacuum source, with the valving arrangment being such that the valve is normally held in a first position in which a through passageway from the vacuum source to the needle is left open for suctioning and evacuation purposes. Upon depression of the plunger on the carpule or syringe, the hydraulic forces, set in motion by the fluid from the carpule, will overcome the force of the valve springs and move the valve to a second position closing off the access port to the vacuum source and permitting the fluid from the carpule to flow through the series of bores and out through the needle and thus into the root canal of the tooth. When the plunger is released, the springs will overcome the decreasing hydraulic pressure and return the valve to the first position.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
International Classes:
A61C5/02; A61C9/00; A61C17/02; A61C17/06; A61C17/08; (IPC1-7): A61C3/00
Field of Search:
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US Patent References:
3727310FOUR-WAY DENTAL SYRINGE1973-04-17Baker
2102591Dental syringe1937-12-21Hagemeier

Primary Examiner:
Peshock, Robert
Attorney, Agent or Firm:
Freeman, And Taylor
What is claimed is

1. A dual purpose instrument for use in root canal therapy for intermittently irrigating and aspirating the canal and carrying a disposable syringe for irrigating and being attachable to a vacuum source for aspirating, comprising; an elongate body having a first bore opening in one end thereof, a second intermediate substantially coaxial reduced diameter bore connected to and communicating with said first bore, and a third further reduced diameter substantially coaxial bore opening in the opposed end of said body and connected to and communicating with said second bore; access means for said vacuum source interconnecting said second bore with the peripheral surface of said body adjacent the point of connection between said second and third bores and adapted to be connected to said vacuum source; a spring-loaded valve releasably seated in one end of said second bore adjacent its point of connection with said third bore; said valve including an elongate slotted end portion; a sealing portion telescoped over one end of said slotted end portion; and a seal body portion spaced from and encircling said sealing portion and being movable axially relatively of said sealing portion and said slotted end portion; and spring means normally spacing said valve means from the end of said second bore and thereby normally closing off communication with said first bore while leaving a passage open between said second and third bores and said access means and vacuum source; said disposable syringe being releasably received within said first bore and being capable of exerting hydraulic pressure within said second bore upon activation thereof; said valve being movable under the force of said hydraulic pressure toward the end of said second bore to a position where said access means are closed off by said seal body portion and a passage is opened from said disposable syringe through said second and third bores; and a disposable needle received on said opposed end of said body with one end thereof disposed within said third bore.

2. The instrument of claim 1 further characterized by the presence of a first spring seated in the end of said second bore and normally separating said seal body portion from the end of said second bore; and a second spring normally urging said sealing portion and said seal body into sealing contact with each other and spacing said slotted end portion from the end of said second bore.

3. The instrument of claim 1 further characterized by the fact that said seal body portion has a reduced diameter area intermediate its ends whereby said hydraulic pressure will move said seal body portion to a position closing off said access means while separating said seal body portion and said sealing portion.


This application relates to an improvement on and an amplification of the principles disclosed in applicant's co-pending application, Ser. No. 147,769, filed May 28, 1971, and now U.S. Pat. No. 3,745,655 and entitled "Endodontic Irrigating Instrument" and applicant's co-pending application, Ser. No. 214,602, filed Oct. 3, 1972, and entitled "Combined Irrigator and Evacuator."


This invention, in general, relates to the field of endodontics or root canal therapy. In particular, the invention relates to a multi-purpose instrument which is capable of establishing an irrigating exchange system through one orifice or needle within the apical areas of the root canal without removing the needle and thus permits the canal to be evacuated of debris, and then by a simple thumb pressure on a conventional, disposable carpule, the irrigating fluid can be injected into the canal without removal of the needle from the canal itself.


The following patent prior art is known to Applicant: Brass et al. U.S. Patent No. 3,624,907, and Lieb et al. U.S. Patent No. 3,488,849.

In addition to the aforementioned prior art, Applicant is aware of numerous injectors and irrigators which in the past have been used for irrigating and chemically cleansing a root canal after it has been mechanically opened. Applicant is also aware of means for vacuuming the chemical substance from the canal. Applicant, however, is unaware of any prior art, other than his own above-mentioned applications, which permits both operations to be quickly and efficiently accomplished through one needle or orifice using only one instrument and a minimum of difficulty on the part of the operator and inconvenience to the patient.

The present invention thus relates primarily to an instrument having improved valving means which permit both the injection of fluid and the vacuuming of the fluid through the same needle or orifice without removing the needle.


It has been discovered that an improved irrigating exchange action can be accomplished by providing a multipurpose instrument.

Thus it has been discovered that by providing an instrument which has a body and an integral handle, the body can be provided with a series of coaxial bores stretching from one end of the body to the other having progressively reduced diameters. It has also been discovered that a suction port can be provided on the body which will intercommunicate between the intermediate of the three bores and a vacuum source. It has thus been discovered that if a spring-loaded valve is implaced in the intermediate bore, with the spring loading being such that the valve is normally open to permit a through and open passageway between the needle end of the body and the suction source, debris can be removed from the interior of the root canal upon manual, fluidic, or electrical actuation of the vacuum source. At this time the spring loading of the valve will close off the largest chamber.

It has also been found that a conventional, disposable syringe can be inserted in the largest chamber, and upon depression of the plunger of the carpule, the hydraulic forces set in motion by the fluid emitting therefrom will overcome the springs in the valve and move the valve to a position in which the suction port is closed off and the valve is opened to permit the fluid from the carpule to pass through the third bore and the needle thus into the root canal.

In this fashion it has been discovered that a complete and adequately cleaned and prepared root canal can be provided, with both the irrigating and vacuuming functions being accomplished with the same needle using one instrument and without the necessity of removing either the needle or the instrument from the tooth.

In this fashion a precision, drop-by-drop metering control of the irrigating fluid is provided, while the positive valve action assures a controlled low pressure irrigation which is unlike the present high pressure, uncontrolled "flushing" methods used in the irrigation of root canals.

Furthermore, it has been found that all of the accessories, such as the valve, the carpule, the tubing, the disposable syringe, and the needle, can be made disposable, thereby improving the sterilization properties.

It has further been found that specially designed servicing tools make assembly and disassembly reliable, simple, and easy.

Further, by using a clear plastic cylindrical tool with a small diameter through bore possessing a millimeter indicia on its external surface, the needle may be bent thereby avoiding insertion to any depth other than desired.

It has also been found that utilization of an instrument of the type generally described above is much more practical in that it is much easier to operate and can be used with any gauge needle or common suction source and will additionally result in an aid to pain relief on the part of the patient since purulent material can be vacuumed away and the root canal irrigated to assure proper drainage quickly since the needle need not be removed and operating time is reduced.

Accordingly, production of an improved, multi-purpose instrument of the character above described becomes the principal object of this invention, with other objects thereof becoming more apparent upon a reading of the following brief specification and claims considered and interpreted in view of the accompanying drawings.


FIG. 1 is a perspective view of the improved instrument showing the needle thereof inserted into a root canal.

FIG. 2 is a partial sectional view of a typical root canal showing how the needle is inserted to the apical end thereof.

FIG. 3 is a vertical sectional view showing the assembled instrument.

FIG. 4 is a partial sectional view showing the instrument during assembly and also illustrating the tools for assembling and disassembling the same.

FIG. 5 is a sectional view showing the valve in its normal position.

FIG. 6 is a sectional view similar to FIG. 5 but showing the valve in the position it would assume upon actuation of the plunger of the carpule.

FIG. 7 is a perspective view showing the length setting tool used in bending the needle to act as a stop.

FIG. 7A is a perspective view of the measuring device of FIG. 7.

FIG. 7B is a perspective view showing the needle inserted in the tooth following bending.


Considering first FIG. 1, it will be noted that the instrument, generally indicated by the numeral 10, includes a body portion 11 and a hand grip portion 12. The hand grip portion 12 is illustrated as being integral with the body, but the instrument could, of course, be made of two pieces if desired. Hand grip portion 12 also includes a finger grip 12a, and with reference again being had to FIG. 1, it will be noted that a tube 14 leads from the body 11 and is threaded through the handle and, by means of a universal connector 15, leads to a vacuum source (not shown), with it being understood that any conventional vacuum source or vacuum actuation means could be employed.

In this regard the body 11 has elongate fins 50,50, one of which has an opening 14a therein for reception of the tubing 14. The projecting angle of projection 34 insures that the tubing will lie along the body between adjacent fins 50,50 and thus be kept out of the operator's way.

FIG. 1 also illustrates a needle 13 inserted on one end of the instrument and projecting into the root canal R of the tooth T. A conventional disposable plunger-operated syringe 20 is illustrated also in FIG. 1, with the plunger 21 being movable in the direction of the arrow 24 within syringe body or barrel 22 in conventional fashion and for purposes which will be described more fully below. Barrel 22 has a tip 25 and also has a retainer tip 26 and cap 27 received thereon in conventional fashion.

FIG. 2 also shows a sectional view of the tooth T, with the root canal R and the lateral canals R1 and R2 being illustrated, with needle 13 being shown inserted into the canal to illustrate how the instrument is capable of operating all the way to the apical end of the tooth.

Turning next to FIGS. 3 and 4 for a more detailed description of the instrument itself, it will be noted that body 11 has an enlarged portion 30 with a bore 31 therein which opens to the end 30a of the instrument itself. Coaxial with and communicating with this bore 31 is a reduced diameter bore 32, and finally a still smaller third bore 33 communicates with bore 32 and opens to the opposed end 30b of the body 11.

Furthermore, an extension or suction port 34 is provided on the periphery of the body 11 adjacent the bore 32. This projection has a bore 35 which normally would communicate with the bore 32, and as shown in FIG. 3, a plastic hose or tube 14 is simply slipped over the end of the projection 34 and connected to the vacuum source after being threaded through opening 14a in fin 50 and openings 60a and 61a in webs 60 and 61 and grooves 62 and 63 of the handle as shown in FIG. 1, for example. In this way the tubing or hose is neatly stored and kept out of the operator's way during the operation.

FIG. 4 illustrates the method of assembling the device, and it will be noted that the valve 40 is first placed in the valve injector 40a, which is a cylindrical device having a first bore 40b in one end of sufficient diameter to hold the valve and a second smaller bore 40c in the opposed end, the purpose of which will be explained below. Once the valve 40 has been implaced in the bore 40b, the valve injector 40a is inserted into the first and largest bore 31 as shown in FIG. 4. Following this, a plunger 91 is inserted into bore 40c, and by depressing the plunger in the direction of the arrow 92, the valve will be forced into bore 32 and become seated in the end thereof as shown in FIG. 3.

Following this, the valve injector 40a and the plunger 91 are both removed, and the device is ready to receive the syringe 20 which is simply telescoped into the bore 31 and seated as shown in FIG. 3.

It might be noted at this point that when the operation has been completed, the carpule, of course, can be simply slipped back out of bore 31, and the valve can be removed by inserting the removal rod 93 in bore 33 and pushing in the direction of the arrow 94 to unseat the valve 40.

Assembly is completed by securing the tubing 14 to the projection or suction port 34 and threading it through the handle and connecting it with a vacuum source as described above, following which the needle 13 can be slipped into bore 33 and the device is then ready for operation.

Referring next then to FIGS. 5 and 6, which are enlarged for purposes of illustration for a detailed consideration of the valve itself, it will be noted that the valve 40 includes a slotted end portion 41 which has a slot 42 therein, with the slot serving as a common passageway for both fluid and vacuum. Telescoped over the projecting end 43 of the end portion 41 is a sealing member 44 which has an enlarged head 46 so as to be T-shaped in cross-section. Encircling both the sealing member 44 and the end portion 41 is a cylindrical body portion 47 which has an internal shoulder 48 for engagement with the enlarged head 46 of the sealing member as shown in FIG. 5. The body 47 is of reduced diameter intermediate its ends. This permits the ends to serve as seals and minimizes leakage problems in the bore or seal is slightly out of round. This also reduces friction problems as the body moves relatively of the bore as will be described below.

A pair of springs 50 and 60 are also provided, with the body spring 50 encircling end portion 41 and having one end seated in the annular depression 47a of body 47 to assure steady, even circumferential pressure, and with its other end resting on the shoulder 32a formed at the juncture of bores 32 and 33.

The second or sealing spring 60 is interposed between the seal body 47 and the end portion 41 encircling seal 44, with one end abutting shoulder 41a of end portion 41 and the other end abutting shoulder 48a of the seal body.

Accordingly, FIG. 5 illustrates the valving arrangement in what might be called the suction phase. Thus when the valve has been inserted as described above, it is in the position of FIG. 5 which is its normal position. Due to the force of the body spring 50, that spring will urge body 47 away from the shoulder 32a, as clearly shown in FIG. 5. In this condition when suction is applied from the vacuum source creating a suction through the needle 13, anything pulled out of the root canal will pass in the direction of the arrows 70, 70, through the slot, out through bore 35 and projection 34, and through the tubing 14. In this way any debris within the canal, including fluids, can be effectively removed by simply inserting the needle 13 into the root canal R and activating the vacuum source.

When it is desired to inject the fluid from the disposable syringe 20 into the canal, it is simply necessary to depress the plunger 21 of the syringe in the direction of arrow 24. Plunger 21 has the usual tip 26 and rubber cap 27 with it being noted that in FIG. 3 the plunger is in its fully depressed condition. Depressing the plunger will force fluid through the end of the carpule and set up hydraulic forces in the direction of arrow 80 within the bore 32. These forces will move the valve 40 to the left of FIGS. 5 and 6 until such time as the valve end portion 41 seats on the shoulder 32a of the body. At that point it will be noted from FIG. 6 that body 47 will have sealed off the passageway 35 in projection 34, thereby closing off the suctioning. Furthermore, at this time the seal spring 60 is compressed by movement of seal body 47, thereby separating the body 47 and the seal 44 as clearly shown in FIG. 6. At that point fluids coming from the disposable syringe will pass through the valve in the direction of the arrow 80, through the slot 81, and out through the needle 13, thereby injecting the irrigating fluid into the root canal.

Upon releasing thumb pressure on the plunger 21 of the disposable syringe 20, the body spring 50 will gradually overcome the decreasing hydraulic pressure, moving the body toward the right and toward the end 30a of the instrument and gradually opening the passageway 35 so that suction can again be achieved.

Simultaneously the seal spring 60 also overcomes the decreasing hydraulic pressure, and as it expands, it will move the body 47 to the right to the position shown in FIG. 5 and effectively seal off the chamber 31, thereby sealing off the fluid reservoir and preventing any accidental drainage of that reservoir by the suction.

It should be noted that while the device has been primarily illustrated and described with relation to an application for an irrigating exchange operation in root canal therapy, it is also usable for other purposes.

Accordingly, by omitting the valve assembly, it can be used for hypodermic injections. Thus if the valve 40 is eliminated and the carpule is placed in the chamber 31, a positive aspirating hypodermic syringe is provided. Accordingly, when the needle 13 has been inserted with the suction or vacuuming on, if the needle is in a blood vessel, for example, the tubing and barrel will be coated with blood and the operator will immediately notice this. If no blood is drawn, the operator then simply depresses the plunger 21 on the carpule 20 which permits the fluid to flow from the carpule directly into the needle and thus into the patient's body. In the event of this usage, it is anticipated that the device may perform this function by designing the device without the handle and in the form of conventional hypodermic syringes.

Furthermore, while the device has been explained with regard to irrigating a root canal, it is believed apparent that sealing of such a canal can also be accomplished. Thus if the carpule 20 is filled with appropriate sealing material, it can be used without the valve 40 for sealing the root canal after it has been thoroughly prepared as described above. In this operation the suction will effectively suction all debris and fluid from the root canal, following which depression of the plunger 21 on the carpule 20 will permit the sealing material to be injected into the canal, and as shown in FIG. 2, the critical apical area will be sealed first, thus permiting complete sealing of the root canal system from the apical end outward to the coronal portion of the tooth.

In addition, a servicing tool has been shown that will simply and effectively permit bending of the needle 13 to any desired working length so that when the needle 13 is inserted into the root canal R, the bend in the needle will ground on the crown of the tooth, thereby assuring that the needle does not penetrate into the root canal any further than the depth desired.

This tool, shown in FIGS. 7, 7A, and 7B, consists of a clear plastic cylinder 90 with a small through bore 91 and with the external surfaces of the cylinder possessing millimeter indicia 92.

The needle 13 is inserted into the bore and advanced until the tip of the needle reaches the proper length marking at which time the tool 90 is moved so as to bend the needle 13.

Thus when needle 13 is inserted into the root canal R (see FIG. 7B), a working length will have been established, and the upper portion of needle 13 will ground on the crown of the tooth and the extent of penetration of the outboard end of the needle will be controlled.

While a full and complete description of the invention has been set forth in accordance with the dictates of the Patent Statutes, it should be understood that modifications can be resorted to without departing from the spirit hereof or the scope of the appended claims.