Amalgam Carrier And Dispenser With Preload Capsule

Abstract

An amalgam carrier and ejector with preload capsule comprises two parallel, elongated tubular members. The tubular members each have a plunger and a common nozzle. One member is adapted to receive an amalgam capsule from which amalgam is extruded into the nozzle by the plunger of one tubular member and is ejected by the plunger of the other tubular member. The capsule has a tubular body, the interior of which is of increasing area toward the nozzle end thereby eliminating any tendency to clog during the extrusion of the amalgam.

Description

This invention relates generally to a dental tool and more particularly to a combination amalgam carrier and ejector as well as to a preload capsule which holds the separate constituents of the amalgam in separate portions prior to use and then permits the constituents to be mixed.

In filling dental caries, it is general practice to use two tools; an amalgam carrier to pick up the amalgam, carry it to the tooth and deposit it in the cavity, and an amalgam condenser which condenses or compacts the amalgam alloy in the cavity. Thus after eliminating the decayed material from the carie and forming a cavity in the tooth, the dentist or his assistant mixes a quantity of amalgam consisting of a combination of mercury and silver sufficient to fill the cavity. The dentist then picks up a small quantity of the amalgam in a carrier and deposits it in the cavity. A separate tool is then used to compact the silver portion and remove any excess mercury. The above procedure is repeated until the entire cavity is filled. It is obvious that this procedure is extremely time consuming in that after the amalgam is prepared, several complete cycles are necessary to fill a single cavity. Since amalgam sets rather quickly, the filling operation must be completed in a short period and, therefore, the dentist is often rushed which leads to improperly filled cavities. Additionally, it is often necessary for the dentist to use both hands to manipulate the various tools.

We have conceived a new and useful amalgam carrier that overcomes the foregoing difficulties and which can be operated with one hand for the ejection of a full charge of amalgam while leaving the other hand free for other tasks. Our invention further contemplates an amalgam carrying capsule which is capable of being carried by an amalgam carrier and ejector and which can be stored with the amalgam constituents separated and then be used to mix same prior to use. An important feature of the invention resides in the provision of a dental tool having first and second tubular members mounted adjacent and parallel to one another with one such member preferably overlying the other and with the lower, or first, member including means for accepting amalgam. A nozzle extends from the upper or second member at an angle thereto and traverses the end of the first member and is in open communication therewith.

Each of the tubular members has a plunger slidably mounted therein and extending from the end opposite the nozzle. The plunger in the upper tubular member includes a flexible part which permits the plunger to deflect while moving between its tubular member and the nozzle. The various parts are so arranged that depression of the plunger in the lower tubular member causes the introduction of amalgam into the nozzle; and depression of the upper plunger causes the amalgam to be ejected from the nozzle into the cavity.

There has thus been outlined rather broadly the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of the invention. It is important, therefore, that the claims be regarded as including such equivalent construction as do not depart from the spirit and scope of the invention.

A specific embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification wherein:

FIG. 1 is a perspective view of the tool of this invention as it is intended to be used;

FIG. 2 is a perspective view of the amalgam capsule and tool showing the relative positions of the two prior to insertion of the capsule into the tool;

FIG. 3 is a transverse sectional view of the amalgam carrier of this invention;

FIG. 4 is a partial cutaway perspective view of the amalgam capsule shown in FIG. 2;

FIG. 5 is a cross-sectional view taken along line 4--4 of FIG. 4 and showing the relationship of the capsule and cap prior to mixing the amalgam constituents;

FIG. 6 is a view similar to FIG. 5 and showing the relationship of capsule and cap for mixing the amalgam;

FIG. 7 is a partial sectional view of the end of the capsule and the cap;

FIG. 8 is a partial transverse sectional view similar to FIG. 7 and showing the relation of the capsule cap and capsule end region for mixing the amalgam constituents;

FIG. 9 is an enlarged view of the amalgam capsule and cap;

FIG. 10 is a transverse sectional view of the amalgam carrier showing extrusion of the amalgam into the carrier nozzle;

FIG. 11 is a transverse sectional view of the amalgam carrier showing ejection of the amalgam;

FIG. 12 is a cross-sectional view of the amalgam carrier taken along line 3--3 of FIG. 3.

The dental tool 10 of our invention is shown in FIG. 1 in the manner in which it is intended to be used. The tool comprises an upper tubular member 12 and a lower tubular member 14. At one end of the tool, the two tubular members converge into a nozzle 15 which is angularly disposed thereto. Plungers 16 and 18 are slidably positioned in each of the tubular members 12 and 14, and each plunger is equipped with a button 19 and 21, respectively, at the ends thereof. Additionally, the tool has a finger grip 20 which is adapted to be grasped by the fingers so that the plungers of the tool may be operated in syringe fashion. It will be noted that the tool is constructed of such size and configuration so that it is easily inserted into the mouth of a patient in such manner that the nozzle 15 can be placed in close proximity to the cavity to be filled with amalgam. The tool may be constructed of any nontoxic material, and for this purpose we prefer to use a combination of molded plastic and metal.

One side of the lower tubular member 14 is cut away as at 22 so as to receive an amalgam capsule 24 is generally shown in FIG. 2. In the figure, the capsule is shown in its preloaded state and comprises a body 25 having one end of reduced diameter 26 forming a shoulder 27. The area of reduced diameter 26, is adapted to accept a cap 28 which is shown in the "ready" position, i.e., in the condition prior to mixing the amalgam constituents.

In FIG. 3, there is shown the arrangement of plungers in the respective tubular members. The lower tubular member 14 has a chamber 35 wherein the amalgam capsule may be placed. The chamber 35 terminates in a rectangular-shaped aperture 42 which is in open communication with the nozzle 15 (FIG. 12). The chamber 35 terminates at its opposite end at a washer 41 which is fixedly secured and provides a guide 44 for the plunger 18. The plunger head 38 is disposed on the chamber side of this washer 41. Between the washer 41 and the end of the tubular member 14 we provide a helical spring 36 which engages a movable washer 40 which, in turn, abuts the end plate 43 of the tubular member. Washer 40 and end plate 43 additionally guide the plunger shaft 39. The guide-in end plate 43 is formed to also allow a projection 37 on the shaft 39 of plunger 18 to pass therethrough. When the plunger advances, the projection 37 engages the movable washer 40 and compresses the spring 36 to bias the plunger 18 toward its extended position. However, the biasing action does not come into play immediately upon depression of the plunger 18, but only after the plunger has been depressed a predetermined distance. This is accomplished by positioning the projection 37 along the plunger shaft 39 in relative close proximity to the button 21. Thus, the plunger 18 is freely movable for a predetermined distance and will only be biased toward its extended position when the plunger head 38 is near or in the nozzle 15.

With respect to the plunger head 38, we provide a forwardly extending edge 49 thereon which is adapted to puncture or pierce. Thus, the plunger head 38 may penetrate the end of capsule 24 as will be more fully described hereinafter.

A plunger 16 is slidably mounted in the upper tubular member 12 and this plunger is partially formed as at 30 of coiled wire so as to be flexible adjacent its head 31. The plunger 16 is used to eject the amalgam material from the nozzle 15 into a dental cavity. The flexible portion 30 allows the head 31 and part of the plunger to enter the nozzle 15 to eject the amalgam located therein. Additionally, the upper tubular member 12 has an enlarged area 32 which houses a helical spring 33 adapted to bear against a stop 34 which enters the housing 32 when the plunger 16 is advanced. Thus, the plunger 16 is always urged toward the projected position. In order to accommodate the plunger head 31, the nozzle 15 extends from the tubular member 12 and is of the same diameter.

We also provide an amalgam capsule for use with the aforementioned tool which permits the storage of amalgam in the capsule with the constituents thereof separated. Prior to use, the amalgam ingredients are mixed in one operation and then the capsule is inserted into the tool for extrusion of the amalgam into the dental cavity. Specifically referring to FIGS. 4 through 9, the amalgam capsule is generally designated by the numeral 24 and comprises a substantially cylindrical body 45 formed with flats 46 and 47. These flats 46 and 47 are designed to coincide with flattened areas in the receiving area 22 of the tool 10 whereby the capsule may be easily and correctly positioned in the tool.

In the manner in which it is intended to be used, the end of the capsule most proximate to the nozzle 15 of the tool is grooved as at 26 to form a shoulder 27 for receiving a cap 28. The interior of the capsule comprises a compartment 48 which is of generally rectangular or round proportions and which progressively increases in area towards the nozzle end of the capsule. The compartment extends completely through the capsule beginning at the plunger end thereof as an opening 50 which is dimensioned to cooperate with the head 38 of the plunger 18. The compartment then gradually increases in size to open towards the nozzle at 52 which is of the same general dimensions as the nozzle aperture 42 (FIG. 13). Thus, when the capsule is positioned in the tubular member 14, the capsule aperture 52 and nozzle aperture 42 coincide so as to provide a continuous opening into the nozzle 15.

We have found that by progressively increasing the area of the compartment 48, amalgam has less tendency to clog and to compact within the capsule during the extrusion thereof by the plunger. Additionally, during extrusion, excess mercury in the amalgam flows past the plunger head 38 into the empty area of the compartment 48.

Initially, the opening 50 in capsule 24 is closed by means of a flangible diaphragm (not shown(adapted to be pierced by the plunger head 38. In cases wherein the capsule is made of plastic, the diaphragm may be an area of reduced thickness which defines the opening 50. Thus, the forwardly extending edge 49 of the plunger head 38 may easily puncture the diaphragm thereby permitting the plunger 18 to enter the capsule compartment 48. As an alternative method, a cap (not shown) may be placed over the end of the capsule during storage thereof and removed prior to placing the capsule into the tool.

The capsule cap 28 is generally cylindrical and has a closed end 29 with a movable diaphragm 54 therein preferably made of hard rubber or plastic and having a small aperture 56 positioned offcenter. The diaphragm 54 defines an enclosure 58 within the cap, the purpose of which will now be described.

In storing the capsule, the amalgam constituents must be kept separate in order to insure that the amalgam does not set. Thus, with the above-described device, the constituents may be kept separate during storage. Specifically, within the enclosure 58, we place one constituent of the amalgam, i.e., mercury, and in the chamber 48 of the capsule, the silver alloy is kept. These materials are kept separate by maintaining the aperture 56 and nozzle aperture 52 out of registry as shown in FIG. 5. During storage, the cap 28 is partially received onto the end 26 of the capsule so that the capsule end abuts the diaphragm 54. To insure that the respective apertures of the diaphragm and capsule are kept out of registry, we provide arrows 60 which indicate to the operator the position of the cap.

After the dental carie has been prepared for filling, the dentist takes the capsule and rotates the cap 28 so that the arrows 60 are in alignment, thereby bringing the apertures 56 and 52 into registry. The capsule cap is then pushed entirely onto the end 26 of the capsule to abut against the capsule shoulder 27 thereby extruding all the mercury into the capsule compartment 48. The entire capsule is then placed in an amalgamator for the mixing procedure, and thereafter, the cap 28 is removed and the capsule 24 is inserted into the injector tool 10. When the plunger 18 is depressed the head 38 enters into the capsule compartment 48 and extrudes the amalgam 62 out of the end thereof into the nozzle 15 (FIGS. 10 and 11). The plunger 16 is then depressed to eject the amalgam into the dental cavity. This operation may be repeated numerous times in order to fill the cavity and until the capsule is emptied of all amalgam. It will be noted that the stop 37 on the plunger 18 does not engage the movable washer 40 and helical spring 36 until the plunger has substantially entered the capsule compartment 48. The biasing nature of the helical spring 36 is intended to insure that the head 38 of the plunger 18 does not interfere with the action of the plunger 16. Similarly, plunger 16 is continually biased to its extended position so that its head 31 will not interfere with the extrusion of amalgam 62 into the nozzle 15.

For ease of use and patient comfort, we have found that an angle 64 of approximately 120.degree. between the nozzle and the tubular members 12 and 14 insures that the tool may be easily inserted into the patient's mouth and that all areas thereof are easily accessible to the nozzle orifice 65. Additionally, our preferred embodiment includes a nozzle orifice diameter of approximately 2.5 mm. This diameter permits easy extrusion of the amalgam material 62 into the average dental cavity.

Claims

We claim:

1. A tool of the class described comprising:

first and second tubular members arranged in parallel, adjacent relationship with said second tubular member overlying said first member, said first tubular member including means for accepting amalgam;

a nozzle extending from said second tubular member and positioned at an angle thereto, said nozzle traversing an end of said first tubular member and being in open communication therewith; and

first and second plungers, said first plunger being slidably mounted within said first tubular member and extending outwardly from the end thereof opposite said nozzle, said second plunger being slidably mounted within said second tubular member and extending outwardly from the end thereof opposite said nozzle, said second plunger including a flexible part to permit deflection thereof into said nozzle, whereby movement of said first plunger in the direction of said nozzle causes the introduction of amalgam into said nozzle and movement of said second plunger in the direction of said nozzle causes the introduction of amalgam into said nozzle and movement of said second plunger in the direction of said nozzle causes said amalgam to be ejected from said nozzle.

2. A tool according to claim 1, wherein said amalgam accepting means comprises an opening in said first tubular member adapted to receive an amalgam capsule.

3. A tool according to claim 1, wherein said first and second tubular members include biasing means adapted to urge said first and second plungers away from said nozzle.

4. A tool of the class described comprising:

first and second tubular members with said second tubular member being mounted parallel to and overlying said first tubular member; said first tubular member having an amalgam cartridge receiving area along one side thereof;

means on said first and second tubular members adapted for finger grasping;

a nozzle extending from said second tubular member and positioned at an angle thereto, said nozzle traversing an end of said first tubular member and being in open communication therewith;

a plunger slidably mounted in said first tubular member and extending outwardly from the end thereof opposite said nozzle, said plunger including a stop mounted a predetermined distance along the length thereof and adapted to engage a washer slidably mounted in said tubular member, said washer abutting a helical spring maintained in said tubular member between a fixedly mounted washer and said first washer, whereby said plunger is freely movable for a predetermined distance and is than biased to a plunger extending position;

a second plunger slidably mounted in said second tubular member and extending outwardly from the end thereof opposite said nozzle, said plunger including a stop which engages a helical spring mounted within said tubular member thereby normally urging said plunger to an extended position.

5. An amalgam capsule for use in an amalgam dispenser having a tubular member adapted to receive said capsule, a nozzle at one end of said member and plunger at the other end of said member said capsule comprising: an elongate tubular body having an interior rectangular chamber of progressively increasing size toward said nozzle; and aperture at one end of said body dimensioned to closely accept said plunger; and an extrusion orifice at the other end of said body, the end of said body having said extension orifice being of reduced diameter so as to receive a cap, said cap having a movable diaphragm including an orifice positioned offcenter in such manner as to permit the extrusion orifice in said body and said diaphragm orifice to be out of registry in one position and upon rotation of said cap to be in registry, whereby the constituents of said amalgam may be stored prior to mixing with one constituent in an enclosure defined by said diaphragm in said cap and another constituent in said capsule and upon rotation of said cap to bring said orifices into registry and movement of said cap toward said body, said ingredients may be mixed.