GB2027601A - Disposable dental capsule - Google Patents

Abstract

The reactive precursors of a dental amalgam are stored in separate chambers of a disposable dental capsule which allows the precursors, mercury and silver powder, to be mixed when desired with no special manipulation of the capsule by the user. The capsule comprises a closed cylindrical container divided into two noncommunicating, internal chambers by a movable, flexible disk. The main, mixing chamber includes a mixing pestle. When placed in a dental amalgamator, the mixing pestle drives the flexible disk to the end of the vessel of the container forcing the mercury to flow around the edges of the disk and to mix with the silver powder, thereby forming the dental amalgam. <IMAGE>

Description

SPECIFICATION Disposable dental capsule BACKGROUND OF THE INVENTION The present invention relates to disposable capsules for prepackaging, storing and eventually mixing mercury and silver powder to form a dental amalgam.

Disposable capsules useful to maintain coreactive components such as dental amalgam precursors of mercury and silver or siver alloy are well-known. In all of the prior art disposable capsules, however, some manipulation of the capsule is required to effect mixing the coreactive components.

It would be very desirable to eliminate any such manipulation of the capsule and especially in the dental art it would be desirable to have a dental capsule containing the dental amalgam precursors from which a dental amalgam could be prepared merely by placing such capsule into an amalgamator.

Examples of prior art of disposable capsules include capsules having rupturable membranes and means for rupturing said membranes prior to mixing of coreactive components. For example, U.S. Patent No. 3,451,540 teaches a disposable capsule comprising a telescoping cylinder which is activated by sliding the separate section together to rupture the membrane which divides the capsule into two chambers and thereby allows the coreactants maintained separate in such chambers to mix.

Similar capsules are disclosed in U.S. Patent Nos. 3,625,349 and 3,595,439 wherein the membrane is in the form of a pouch, containing a coreactant and such pouch is ruptured by either squeezing through a rotating mechanism or a sliding mechanism until it bursts. See also U.S.

Patents Nos. 3,907,106; 3,860,114; 3,841,467; 3,831,742,3,655,035; 3,638, 918; 3,7 56, 57 1 ; and 1,774, 258 for similar capsules.

Disposable capsules which utilize a removable plug to isolate the coreactive components and which plug is removed to allow such components to mix are also known in the art. See for example, U.S. Patent No. 3,275,302, wherein a ball or a disk is positioned to divide the capsule into two chambers each containing a coreactive component. This capsule is activated by turning the capsule upside down to dislodge the ball or disk. See also U.S. Patents Nos. 3,796,303; 3,809,225; 2,527,992; 2,527,991; and 3,785,481 for other capsules utilizing removable plugs.

Other disposable capsules employ a passageway between the two chambers which can be closed and opened by either twisting, sliding or unscrewing one or more sections of the capsule. For example, in U.S. Patent No.

3,357,545 the top of the capsule is unscrewed to remove a stem on the upper section of said capsule from a conduit in the lower section.

Removal of such stem allows the coreactive component maintained in the upper section to fall into the lower section. Also see U.S. Patents Nos.

3,139,180; 3,139,181; 3,917,062; 3,963,120; and 3,924,741 for similar capsules.

It is accordingly an object of the present invention to provide a capsule for prepackaging and storing the precursors of dental amalgam, particularly mercury and silver or silver alloy. It is a further object of this invention to provide a dental capsule which allows the precursors to be mixed and the amalgam formed with no special manipulation of the dental capsule on the part of the user. It is a yet further object of this invention to provide a dental capsule which minimizes the possibility of mercury escaping into the environment either before or during the formation of the dental amalgam. These and other objects of the present invention will be apparent from the ensuing description and claims.

SUMMARY The disposable dental capsules in one embodiment of the present invention comprise a closed cylindrical container divided into two, noncommunicating, internal chambers by a movable, flexible disk. A premeasured quantity of mercury is contained in one chamber, and a corresponding reactive amount of silver powder and a mixing pestle are contained in the other chamber. One face of the flexible disk is convex and contoured to conform to the shape of the opposing end of the chamber containing the mercury which is preferably cone shaped. When the capsule is placed in an amalgamator, the pestle drives the flexible disk to nest with the end of the container, forcing the mercury to flow around the edges of the disk and mix with the silver powder.

The capsule is conveniently composed of two, interlocking cylindrical members, each having one closed end and one open end and including means for joining the open ends to form a closed container.

The capsule also preferably includes internal means for locating and securing the flexible disk against inadvertent movement prior to use of the capsule to prevent premature mixing of the amalgam precursors. The capsule may also contain vanes or grooves in the wall of the mercury chamber to promote the flow of mercury around the disk when the capsule is placed in the amalgamator and the disk is driven to the end of the capsule.

The advantage of the dental capsule of the present invention resides in the fact that no manipulation of the capsule by the dentist or technician is required to effect mixing of the components. Since the capsule forms a closed container and there are no external moving parts, the possibility of mercury escaping into the environment is substantially eliminated.

After the amalgam has been formed inside the capsule, the cylindrical members are separated to remove the amalgamated composition. The two cylindrical members, one of which contains the flexible disk, and the pestle are then discarded.

In another embodiment of the present invention, the capsule comprises a hollow cylindrical section having an axially located shoulder spaced from the ends of the cylinder such that the internal diameter of the cylinder is constructed at the shoulder; a detachable cap closing one end of the hollow cylindrical section; and a flexible plug having a stem inserted through and flexibly engaged by the constriction in the cylindrical section. A flange extending outwardly from the end of the stem is spaced from the shoulder of the cylinder and frictionally engages the inner wall of the cylindrical section along the entire periphery thereof whereby the cylindrical section is divided into two noncommunicating chambers.

The mercury is placed in the chamber enclosing the stem of the plug, while the silver powder is contained in the other chamber of the cylinder. A pestle in the chamber with the silver powder is of sufficient weight and dimension so that when the capsule is placed in an amalgamator, the pestle impacts upon the flexible plug to drive the plug toward the shoulder of the cylindrical section.

Upon such movement, the stem of the plug is forced further through the constriction in the cylinder until the flange of the plug nests with the shoulder, thereby forcing the mercury past the edge of the flange and into the chamber containing the silver powder to form the dental amalgam.

DESCRIPTION OF DRAWINGS FIGURE 1 shows an external view of a capsule of the present invention.

FIGURE 2 shows an exploded, partial, crosssectional view of the capsule of FIGURE 1.

FIGURE 3 shows a cross-sectional view of the capsule of FIGURE 1 prior to activation.

FIGURE 4 shows in greater detail the relationship of the flexible disk and the assembly of the cylindrical sections of the capsule of FIGURE 3.

FIGURE 5 shows the capsule of FIGURE 1 after activation and mixing of the coreactive components.

FIGURE 6 shows a partial sectional view of the flexible disk and cylindrical sections in a second embodiment of the capsule.

FIGURE 7 shows a partial sectional view of the flexible disk and cylindrical sections in a third -embodiment of the capsule.

FIGURE 8 shows a partial sectional view of the flexible disk and cylindrical sections in a fourth embodiment of the capsule.

FIGURE 9 shows an exterior view of another embodiment of the capsule of the present invention.

FIGURE 10 shows a cross-sectional view of the capsule of FIGURE 9 prior to activation.

FIGURE 11 shows an exploded view of the capsule of FIGURE 10.

FIGURE 12 shows a cross-sectional view of the capsule of FIGURE 10 after activation and mixing.

FIGURE 13 shows the periphery of the flange of the movable plug in cross section.

FIGURE 14 shows the relationship of the periphery of the flange of FIGURE 12 and the internal walls of the capsule.

FIGURE 15 shows the end view of the capsule of FIGURE 9 as taken from line 1 5-1 5.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIGURES 1-5, there is illustrated as a preferred embodiment of the present invention a disposable capsule comprising a first cylindrical section 10 having an open end 9 and conically-shaped closed end 12, a second cylindrical section 1 8 having an open end 1 9 and closed hemispherical end 20, and a flexible disk 14 which divides the assembled capsule into two noncommunicating, internal chambers 23 and 24 as best seen in FIGURE 3.

Flexible disk 14 is positioned in cylindrical section 10 with the edges of the disk engaging the walls of the section to form a continuous seal around the periphery thereof. Surface 13 of flexible disk 14 has a positive conical shape conforming to the negative conical shape of end 12 of cylindrical section 10 so that the disk nests with the cylinder end when forced against that end of the capsule.

The cylindrical section 10 also has an axiallyextending groove 11 about its open end which allows cylindrical section 10 to telescopically engage open end 1 9 of cylindrical section 18, whereby a sealed capsule is formed when the first and second cylindrical sections are so engaged.

The wall thickness of cylindrical section 1 7 about the circumference of open end 1 9 is slightly greater than the depth of axially-extending groove 11 in cylindrical section 10 whereby when the cylindrical sections are telescopically engaged an axially-extending step 22 is provided in the interior of the capsule at the point where the two sections are joined.

Cylindrical section 10 includes a plurality of vanes 1 5 which extend along the wall thereof from the closed end toward the open end of the cylinder. In the illustrated embodiment, eight vanes are provided which are equidistantiy oriented about the inner wall of the cylindrical section. It is desirable to have at least three vanes to keep the disk from cocking either during loading of the capsule or during activation as described below.

The dimensions of the vanes are selected to hold the flexible disk in a proper spaced relationship from the closed end of the cylindrical section without preventing the disk from nesting against such end when the capsule is activated. In a typical dental capsule having overall dimensions of from about 1 or 1-1/4 inches by approximately 1/2 inch diameter, vanes 1 5 may protrude from the inner wall of the cylindrical section about 3 to 1 5 mils and be of 7 to 15 mils wide. The vanes may be tapered toward the open end of the cylinder to assist the disk in riding up on the vanes during mixing, provided, however, the angle must be sufficient to prevent dislocation of the disk during storage and shipping of the loaded dental capsules.It has been found that as the size and number of vanes are increased, more of the reactive component is retained in the capsule after mixing, and the skilled artisan will therefore choose dimensions for such vanes with a view toward securing the position of the disk during storage and shipping while minimizing the retention of residules in the capsule.

As best illustrated in FIGURE 4, the flexible disk 14 engages the inner wall of the capsule completely around the inner periphery of cylindrical section 10 and is held in place between vanes 1 5 and step 22 thus dividing the capsule into a first internal chamber 23 and a second internal chamber 24. The edge of the disk is preferably of a slightly greater thickness than the space between the step and the vanes to place the disk under light compression in the assembled capsule. In a typical dental capsule, such space may vary from about 5 to 60 mils and is typically about 30 mils.

In the illustrated embodiment, disk 14 has a conical surface extending into chamber 23 conforming to the conical shape of the opposing end of that chamber. The end of the chamber and the corresponding face of the disk may also be eliptical or hemispherical, but are preferably not flat since there would be a greater tendency to trap mercury between such flat surfaces during activation of the capsule.

Also as illustrated, chamber 23 contains mercury 25 and is appreciably smaller than chamber 24 which contains silver powder 27 and pestle 26. The precharged capsule may be activated by shaking in a dental amalgamator whereby the capsule is reciprocated in a direction along the major axis of the capsule. The pestle rebounds between the capsule end 20 and the opposing surface of the disk driving the disk quickly toward the closed end 1 2 of cylindrical section 10. As the disk moves into the nesting position against the surface of end 12, the mercury is hydrostatically forced to flow around the edges of the disk and into chamber 24. This flow of mercury is promoted by vanes 1 5 on the wall of section 10 which force openings in the seal around the edge of the disk.After a short time in the amalgamator the capsule has, in effect, only a single large internal chamber of a volume substantially equal to the combined volumes of original chambers 23 and 24 and containing both the mercury and the silver.

The edge of the flexible disk, as previously noted, must seal against mercury leakage from chamber 23 during storage and shipping. In one embodiment illustrated in FIGURE 4, the edge of the disk is grooved to provide a double seal line at the upper end lower surfaces of the disk to enhance its sealing capacity. Disk 14 is further provided with a concave face on the side facing the pestle which is believed to direct the force of the moving pestle uniformly across the disk thereby minimizing cocking as the disk rides up on the vanes and moves toward the closed end of cylindrical section 10.

The two cylindrical sections comprising the capsule of the present invention are provided with means to interlock the assembled capsule to insure the sections will not prematurely separate during shipping and handling. Referring now to FIGURE 1, cylindrical section 1 8 is provided with axially-extending retainer flange 40 about the outer surface over which one or more lugs 41 integral with and axially-extending flange 42 on the outer surface of cylindrical section 10 snap fit.

Flanges 40 and 42 are also useful in separating the hollow cylindrical sections. As shown in FIGURE 5, the lugs 41 may be provided with extensions 43 beyond retainer flange 42 to provide a means for unsnapping said lugs by squeezing said extensions toward the body of the capsule.

In the illustrated embodiment of FIGURES 1-5, cylindrical section 10 had external ribs 16 radiating from the center of the closed end to conform the shape of the capsule to the shape of conventional amalgamator clips. The form shown in FIGURE 1 is preferred because it maintains uniform wall thickness, and, hence, uniform cooling during molding of the capsule. Cylindrical section 1 8 is also provided with suitable frictionproducing, gripping means about its external circumference such as the knurling 21 illustrated in FIGURE 1 to assist in holding and opening the capsule after activation.

Referring now to FIGURES 6-8, there are illustrated additional embodiments of the present invention wherein alternate means are utilized for locating and securing disk 14 within the capsule. In FIGURE 6, disk 14 is provided with an annular flange 31 which extends into a space and is compressed between the base of groove 11 in cylindrical section 10 and end 1 9 of cylindrical section 18. During activation of the capsule flange 31 is sheared or pulled free by the action of the pestle on disk 14, and the disk is released and driven to the end of cylindrical section 10.The side wall vanes illustrated in the previous figures are not required in the embodiment of FIGURE 6 since the construction of the disk does not offer significant resistance to the flow of mercury around the edge of the disk once it has been freed from the annular flange.

Referring now to FIGURE 7, there is illustrated another embodiment wherein disk 1 4 is located and secured in circumferential groove 32 formed in the wall of the capsule at the juncture of the two cylindrical sections. In a further embodiment illustrated in FIGURE 8, disk 1 4 is located and secured between annular ridge 33 in cylindrical section 10 and lip 22 formed by end 19 of cylindrical section 1 8.

Those skilled in the art will appreciate that many other arrangements may be employed to locate and secure disk 14 within the capsule prior to activation. For example, the disk may be cemented to the wall of the capsule, or fused in place by induction bonding, or held in place by other mechanical means. The present application is accordingly not limited to any structural variation described herein.

The cylindrical sections of the capsule may be formed from any material which is inert to the coreactive components contained therein. In general, the cylindrical sections should be made of rigid material, such as metal, plastic, or the like, and in a preferred embodiment they are made of rigid, thermoplastic material such as polycarbonate, polyacrylic, polyvinyl chloride, or the like. The material of choice for ease of fabrication is a polycarbonate such as LEXAN from General Electric Company or MERLON from Mobay Chemical Corporation; or an ABS polymer such as CYCOLAC ABS from Borg-Warner Corporation.

Disk 14 is preferably made of a resilient, flexible material such as, for example, acetal or polyester (e.g., DELRIN and HYTREL respectively, both being available from E. I. du Pont de Nemours 8 Co.), or the like thermoplastic materials. However, the material of choice is HYTREL.

The disk and the cylindrical sections am preferably formed by injection molding, but any suitable technique for forming the materials may be employed.

The use of rigid material for the hollow cylindrical sections minimizes retention of mercury in the capsule. Further, the combination of a rigid capsule and a flexible disk requires less strict manufacturing tolerances because the flexible material of the disk will adjust to minor deviations in the structure of the hollow cylindrical sections leading to more economic and efficient manufacture of the capsule of the invention.

To fill the dental capsule of the instant invention, a measured amount of silver alloy powder 27 or tablet of such powder is placed in cylindrical section 1 8 along with a mixing pestle 26 of sufficient weight to drive disk 14 back into cylindrical section 10 upon mixing. The proper amount of mercury to form dental amalgam with the silver powder is placed in cylindrical section 10, conveniently when it is positioned with the closed end downward. The flexible disk 14 is then placed in cylindrical section 10 and maintained in proper position by frictional engagement with the inner wall of the cylinder section or other suitable means. Cylindrical section 10 containing the mercury and the flexible disk 14 are then inverted and secured to cylindrical section 18 by means of lugs 41.

Referring now to FIGURES 9-15, the capsule of the illustrated embodiment comprises a hollow cylindrical section 110 having an axially located shoulder 111 spaced from the upper end 112 and the lower end 113 of section 110 such that the internal diameter of section 110 at a point spaced from ends 111 and 11 2 is provided with a constriction.

In the embodiment shown in FIGURE 9, it is noted that the upper portion of section 110 is provided with ribs 114 which aid in gripping the capsule in the amalgamator and allow ease of molding the capsule. The ribs are oriented radially about the upper portion of section 110 and in an equidistant manner. In the embodiment shown, 1 6 ribs are provided; however, greater and fewer numbers are suitable depending on esthetics, design considerations and amount of distortion and shrinkage which can be tolerated during fabrication of the capsule.

The ribs are curved at the upper end 112 of section 110 and extend toward said lower end 113 and merge into the walls of section 110 at a point proximate shoulder 111. Shoulder 111 divides the internal volume of section 110 into a stem receiving chamber 11 5 toward the upper end of section 110 and chamber 11 6 for retaining the coreactive components toward to lower end of section 11 0.

A flexible plug 117 having a stem 118 and a flange 11 9 is positioned in chamber 116 to divide the chamber into two chambers for separately containing coreactive components. The periphery of flange 119 conforms in shape to the internal diameter of chamber 116 although of somewhat greater dimension and is generally circular and disclike. As shown, the flange 119 is located about the lower end of stem 118 and engages the internal wall of chamber 116 in a sealing manner The stem 118 frictionally engages shoulder 111 toward its upper end in a sliding fit. The material of the plug is resiliently flexible whereby the flange provides an adequate seal between said coreactive component containing chambers 120 and 121 while allowing the plug to move back toward the upper end of section 110.Preferably, plug 11 7 is an integrally molded thermoplastic such as low density polyethylene, polyester e.g., HYTRELTH, and polyacetral, e.g., DELRINTH.

Shoulder 111 1 1 may be of any shape whereby it axially engages stem 118 in a sealing manner yet will not prohibit the sliding of the stem as the plug is forced toward upper end 112. In the embodiment shown, the shoulder is frustoconical in cross section with the plane engageing the stem. Of course, the shoulder may be rounded or pointed in cross section, however, it has been found that the frustoconical cross section provides the best balance of sealing with sliding functions.

It should be pointed out that the sealing function of shoulder 111 is not as critical as the sealing function of flange 11 9 since leakage at the shoulder would only allow the reactive component to pass into the environment while leakage at the flange might result in the premature reaction of the coreactive components. However, when mercury is contained in chamber 120 it is critical for safety reasons that the shoulder provide at least as effective a seal as the flange.

As will be apparent, plug 11 7 is positioned in section 110 in a manner to provide chambers 120 and 121 with adequate volumes for holding the required amounts of coreactive components. The relative volumes of chambers 120 and 121 can be adjusted by positioning plug 117. Chamber 120 is especially suitable for holding liquid coreactive components such as mercury. Chamber 121 will generally contain either a liquid or a powder coreactive component such as silver or silver alloy.

As noted above, the illustrated capsule functions by moving the plug back toward the upper end of the section 110 to diminish the volume of chamber 120 with a corresponding increase in the volume of chamber 121, thereby forcing the coreactive liquid component into chamber 121. In order to provide adequate force to move the plug in the aforesaid manner, as well as to assist in mixing the coreactive components, a pestle is provided in chamber 121. The dimensions of chamber 121 along the long axis is substantially greater than chamber 120 so as to allow the pestle to generate greater force during the shaking in the amalgamator.

Chamber 121 is sealed with an end cap 122 which is detachably secured to the lower end of section 110.

Cap 122 as shown has a hemispherically shaped lower end 123 integral with a hollow cylindrical upper end 124 which telescopically engages an axially extending groove 125 located about the lower end of section 110. In the illustrated embodiment, cap 122 is joined to section 110 in a flush manner to provide a smooth internal surface for chamber 121. It has been found that increasing internal surface irregularity results in higher residuals of both the coreactive components and the reaction products remaining in the capsule after use.Besides the obvious economic disadvantage in having increased residuals, the environment contamination problems of disposing of used capsules containing mercury or other noxious substances will be apparent Other means for detachably securing cap 122 to section 110 will be obvious to one skilled in the art, e.g., screwing means, snapfit, pushfit, etc., however, for the purpose of providing a regular internal surface for chamber 121 the aforedescribed method is preferred.

As shown, the cap may be provided with an external axially extending ridge 126 to facilitate detachment from section 110. Note also that in the illustrated embodiment the hollow cylindrical upper end 124 of the cap is dimensioned to be greater in height than the length of axially extending groove 125. This structural relationship provides an external, axially extending groove 1 27 adjacent ridge 126 for additional ease of detaching the cap with a thin instrument or a fingernail.

To return to the relationship of plug 11 7 to section 110, it will be apparent from the figures that the length of the stem is preferably less than the distance between shoulder 111 and upper end 112, i.e., the length of the stem receiving chamber 115.

To ensure the maximum passage of the reactive component contained in chamber 120 into chamber 121, it is desirable that the flange be forced toward the upper end of section 110 until the upper surface 11 9a of the flange engages the shoulder 111. The stem must, therefore, not be of such length as to be blocked from lateral movement by the grips of an amalgamator thereby preventing the flange from engaging the shoulder.

The easiest way to ensure that the lateral movement of the plug will not be restricted by any of the amalgamator grips available to the dentist or other dental practitioner is to maintain the length of the stem less than the length of the stem receiving chamber.

In the typical dental capsule, i.e., of dimensions of 1 to 1-1/4 inches by approximately 1/2 inch, the stem receiving chamber 11 5 may have a length of 0.1 6", chamber 120 may have a length of 0.133", and chamber 121 may have a length of 0.81" (prior to activation).

Also as a further safeguard against mercury passing the seal provided by shoulder 111 into the environment, a removable tape or end cap (not shown) can be used to seal the upper end of said section 110. If such a removable tape or cap is utilized, an air vent may be provided to prevent the formation of an airlock during movement of the stem into chamber 115. An air vent might also be provided in the walls of chamber 120 proximate shoulder 111 to prevent an airlock from restricting the movement of flange 119 toward said shoulder.

An additional structural feature of instant capsule is provided by shaping the upper surface of the flange to conform to the lower surface 111 a of shoulder 111. This feature ensures mating of these surfaces and more complete transfer of the reactive component from chamber 120 to 121 since at the conclusion of the activation, chamber 1 20 will be essentially nonexistent. This is illustrated most clearly in FIGURE 12.

The capsule may be activated by shaking in a dental amalgamator wherein the capsule is agitated along the direction perpendicular to the plane of said flange. The pestle will strike the lower surface of the flange and force the flange back toward the shoulder of the hollow cylindrical section. As can be seen in FIGURE 12, the mercury is squeezed past the periphery of the flange. To facilitate passage of mercury, the periphery of the flange is preferably of reduced thickness as compared to the general thickness of the flange, i.e., the periphery is tapered (see FIGURE 13).

After mixing, the capsule may be pulled apart to obtain the amalgam.

To fill the dental capsule of the instant invention, plug 11 7 is positioned in the hollow cylindrical section 110 towards the lower end of section 110 whereby stem 11 8 is not engaged by said shoulder 111 yet the flange 119 is in sealing engagement with the internal walls of section 110. Mercury is passed into said section 110 through the valve receiving chamber 11 5 and plug 11 7 is moved towards the upper end of section 110 until stem 1 engages shoulder 111 ion a sealing manner. End cap 1 22 may be filled with silver or silver alloy, in either powder or tablet form, a pestle placed therein, and secured to the lower section of section 110. Alternatively, the silver or silver alloy and/or the pestle may be placed in chamber 116 after the mercury has been sealed into chamber 120 and the end cap secured to section 110.

According to the invention, the premeasured components can be mixed without being touched or measured by the user in a more accurate and simple fashion than previously known. It should be understood that while the container of the invention has been exemplified in the mixing of dental amalgam, other dental compositions such as acrylate polymer dental filling materials may be packaged and mixed therein. Further, the container may be used in fields other than dentistry where a liquid component must be kept separate until just prior to use, as for example, in the prepackaging of epoxy resins and accelerators for the formation of cements.

Claims (32)

1. A disposable dental capsule comprising a first hollow cylindrical section having an open end and a closed end; a second hollow cylindrical section having an open end and a closed end; means for joining and securing said open ends of said first and second cylindrical sections to form a closed cylindrical container; a displaceable, flexible disk having an edge in sealing engagement with the inner wall of said cylindrical container whereby said container is divided into two, noncommunicating inner chambers, and having one face conforming to the shape of the inside surface of the opposing end of said container, whereby when said disk is displaced to said end of said container, the face of said disk nests therewith and one of said inner chambers is substantially eliminated.

2. A capsule of Claim 1 wherein the inside surface of one end of said container is concave and the opposing face of said disk is convex.

3. A capsule of Claim 2 wherein said face of said disk has a positive conical shape and said end of said container has a corresponding negative conical shape.

4. A capsule of Claim 1 wherein said first hollow cylindrical section has an axially-extending internal groove about its open end telescopically engaging the open end of said second cylindrical section.

5. A capsule of Claim 4 wherein said first and second cylindrical sections are secured in said telescopic engagement by means of lugs on said first section engaging a circumferential flange extending from said second section.

6. A capsule of Claim 1 wherein said innerwall of said container includes means for positioning and securing the edge of said flexible disk.

7. A capsule of Claim 6 wherein said disk positioning and securing means comprises a circumferential groove in said wall receiving said edge of said disk.

8. A capsule of Claim 6 wherein said disk positioning and securing means comprises circumferential ridges on said wall on either side of said edge of said disk.

9. A capsule of Claim 6 wherein said disk positioning and securing means comprises a circumferential ridge on said one side of said edge of said disk, and a plurality of vanes circumferentially spaced around said wall and extending to the other side of said edge of said disk.

1 0. A capsule of Claim 6 wherein said disk positioning and securing means comprises a circumferential groove in said wall between the juncture of said first and second cylindrical sections receiving an annular flange extending from the edge of said disk.

11. A capsule of Claim 1 including a predetermined amount of mercury in the inner chamber defined by the face of the disk shaped to conform to the end of the container, a coreactive amount of silver in the other inner chamber, and a mixing pestle in the chamber containing the silver.

12. A disposable capsule comprising: a first hollow cylindrical section having an open end and a closed end, said first section having an axially-extending intemal groove about its open end and a plurality of vanes spaced from said groove and extending perpendicularly toward said closed end; a second hollow cylindrical section having a closed end and an open end, said open end telescopically engaging said internal groove of said first section and being of sufficient thickness to provide an axially-extending step within said first section; and a flexible disk having one face engaging said axially-extending step and an edge engaging the walls of said first section at the space between said perpendicularly-extending vanes and said step, said disk thereby dividing said capsule into two noncommunicating chambers.

13. The capsule of Claim 12 wherein the other face of said flexible disk is shaped to nest with the internal face of the closed end of said first cylindrical section.

14. The capsule of Claim 13 wherein said face of said flexible disk has a positive conical shape, and the internal face of the closed end of said first cylindrical section has a corresponding negative conical shape.

1 5. The capsule of Claim 12 wherein the edge of said flexible disk has a thickness of from 5 to 60 mils.

1 6. The capsule of Claim 12 wherein said edge of said flexible disc is of a thickness greater than the space between said axially-extending step and said perpendicularly-extending vanes.

17. The capsule of Claim 12 wherein said first and second cylindrical sections are each provided with interlocking means.

18. The capsule of Claim 12 including a predetermined amount of mercury in the chamber of the second cylindrical section, a coreactive amount of silver in the chamber of the first cylindrical section, and a mixing pestle in the chamber containing the silver.

19. A capsule divided into two chambers by slidable barrier means, said slidable barrier means movable from a first position to a second position by a force from within said capsule directed against such slidable barrier when said capsule is shaken, said chambers being capable of holding coreactive components separate while said slidable barrier is in said first position and said chambers being in communication when said slidable barrier means is in said second position.

20. A disposable capsule comprising (1) a hollow cylindrical section, said hollow cylindrical section having an axially located shoulder spaced from the ends of the cylinder such that the internal diameter of such cylinder at a point spaced from its ends is thereby provided with a constriction; (2) an end cap detachably secured to the lower end of said hollow cylindrical section; and (3) a flexible plug comprising a stem having an upper portion which is inserted through and frictionally engages said constriction and a flange extending outwardly about the lower end of said stem, said flange being spaced from said shoulder and said end cap and being frictionally engaged with the inner wall of said hollow cylindrical section along the entire periphery thereof, whereby said flange divides said cylindrical section into two non-communicating chambers.

21. The capsule of Claim 20 wherein the edge of said flange is tapered around the entire periphery thereof.

22. The capsule of Claim 20 including radially oriented equidistantly spaced ribs about upper portion of the hollow cylindrical section.

23. The capsule of Claim 22 wherein said ribs are curved toward the upper end of said hollow cylindrical section, extend toward the lower end of hollow cylindrical section and merge with the walls thereof at a point proximate said shoulder.

24. The capsule of Claim 20 wherein said shoulder divides the internal volume of said hollow cylindrical section into an upper stem receiving chamber and a lower chamber for retaining a coreactive component.

25. The capsule of Claim 20 wherein the periphery of said flange is disclike and of greater dimension than the internal diameter of said hollow cylindrical section.

26. The capsule of Claim 20 wherein said plug is made of a resiliently flexible material.

27. The capsule of Claim 20 wherein said shoulder is frustoconical in cross section.

28. The capsule of Claim 20 wherein said hollow cylindrical section includes an axially extending groove about its lower end.

29. The capsule of Claim 28 wherein said end cap includes a hemispherically shaped lower end and a hollow cylindrical upper end which is dimensioned to telescopically engage the axially extending groove of said hollow cylindrical section.

30. The capsule of Claim 20 wherein said end cap includes an external axially extending ridge.

31. The capsule of Claim 24 wherein said stem is lesser in length than the length of said stem receiving chamber.

32. The capsule of Claim 20 wherein the upper surface of said flange conforms in shape of the lower surface of said shoulder.