CA1222424A - Syringe for extrusion of semi-plastic material - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The invention comprises a syringe for extrusion of a semi-plastic mass, or a mass having a paste-like consistency.
In a preferred embodiment, the syringe is so designed to permit mixing of two components of a plasticizable mixture within the syringe barrel. The bore of the syringe barrel is flared to facilitate extrusion of the plastic mass therefrom. The parts of the syringe ready for use are packaged in a one-piece tray which serves not only for shipping and storing of the syringe, which may be pre-loaded with one of the components of the plasticizable mixture, together with the associated syringe parts, but which also serves, when opened for use, as a convenient tray for handling the syringe while mixing the two components of the plasticizable mixture prior to extrusion.
The syringe is particularly applicable in dental restorative processes for mixing and extruding hydroxylapatite and other ceramic materials.

Description

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This invention relates to syrinCJes useful in extrud-inc3 a semi-plastic mass, or a mass havincJ paste-like consistency, therefrom.
The use of two component mi.YincJ syrincJes for dissolvinc~ a solid medicament in a liquid diluent prior to injec-tion of the solution is well known in medical praetice.
An example of such syrincJes is illustrated by LindbercJ et al, United States Patent ~,060,082, which describes a syrincJe combina-tion comprisincJ a mixer-dispenser syrincJe, usually containing a solid medicament, which is connected via a collapsible COnneCtirlCJ sleeve to a carrier syrincJe, usually containincJ a licluid di:Luent used to dissolve the medicament in the mixer/clispenser section. ~hen it is desired to use the syrincJe, the two syrinc~e sections are telescoped to~ether thus foreiny a fill needle positioned between the two syrinc~e seetions to ma]ce a con~municatincJ connec-tion between the mixer/
dispenser and t.he carrier syrincJe sections. The liquid contents of the carrier seetion can then be ejeeted throucJh the fill needle into the mixer/dispenser seetion. After the solid medieaMent has dissolved, a hypodermie needle is attaehed to the exit end of -the mixer/dispenser seetion, a plunger is attaehed -to a rubber pis-ton closincJ -the othe~ encl, and the liquid eontents can then be ejeeted.
There are various means for makinc3 eonneetion between two seetions of a two eomponent mixincJ syrincJe, the eollapsible sleeve and fillincJ needle deseribed in the above-noted Lindber~
et al patent beincJ one sueh means. Another means of aehievincJ
sueh intereonneetion is illus-trated in Choksi et al, United States Patent 4,046,145, which describes a Luer lock/Luer .:
joint two-part unit.

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However, syringes for dispensing liquids are diEfi-cult to use in the extrusion of semi-plastic masses, and may in some cases be inoperative for such purposes. While the prior art is thus instructive on the problem of mixing two components and dispensing a resultlng solution in liquid form, so far as is known, the art is silent on the problem of mixiny two or more components within a syringe barrel, so as to form a semi-plastic mass, or extrusion of a semi-plastic mass from a syringe system.
The present invention is directed to a mixing/
dispensing syringe ~or use in the extrusion of a wetted, semi-plastic mass, which comprises in combination: (A) a barrel o~
generally uniform wall thic~ness which is closed at its upper end by (B) a flexible piston slidable within the bore of said barrel and (C) a plunger rod removably attached to the piston, wherein the bore of said barrel is slightly flared from its upper to its lower end to provide relief of frictional resis-tance to extrusion.
The barrel may be pre-loaded with a wetted semi-plas-~0 tic mass or with one component oE a multi-component plasticiz-able mixture to be wetted with a liquid component, and may be fitted at its lower or exit end with removable means for making interconnection with a filling syringe used to add to the dis--pensing syringe a second component of the plasticizable mix ture. The barrel is provided at its upper end with a flexible slidable piston which is provided with means for making posi-tive engagement with a plunqer rod. The syringe is optionally provided with means to permit escape of air from the barrel thereof when the syringe is being filled with a second compo-nent from a filling syringe. The bore of the barrel of thedispensing syringe is flared from its upper end to its lower , end in order to facilitate extrusion of the semi-plastic mass from the barrel.
Another aspect of the invention is directed to a dispensing syringe for use in the extrusion of a wetted semi-plastic mass, which comprises in combination: (A) a barrel of generally uniform wall thickness which is closecl at its upper end by (B) a flexible piston slidable within the bore of said barrel, and (C) a plunger rod for removable attachment to the piston, wherein the bore of said barrel is slightly flared from its upper to its lower end to provide relief of frictional resistance to extrusion and the barrel is pre-loaded with one component of a plasticizable mixture.
A further aspect of the invention is directed to a package for shipping and storing a mixing/dispensing syringe for use in the extrusion of a wetted, semi-plastic mass, composed of a plasticizable mixture of two or more components, which comprises: (I) a thermoformed plastic tray which is sealed over its open upper face by (II) a cover sheet, wherein said tray contains (III) a mixing/dispensing syringe which comprises in combination: (A) a barrel of generally uniform wall thickness which is closed at its upper end by (B) a flex-ible piston slidable within the bore of said barrel, and (C) a plunger rod for removable attachment to said piston, wherein the bore of said barrel is slightly flared from its upper to its lower end to provide relief of frictional resistance to extrusion. The barrel of the dispensing syringe in said package may be pre-loaded with a wetted semi-plastic mass or with one component of a multi-component plasticizable mixture, particularly with a solid, powdered ceramic material, and may be fitted at its lower end with removable means for making interconnection with a filling syringe.

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In order to fully describe the invention herein and the manner of using it, it will be necessary to use certain portions of a syringe unit as points of reference to illustrate relative movements of the parts of the syringe. ~herefore, thro-lcJhout this specification and in the appended claims, the terms "lower" and "downwards" are intended to refer to the exit end of the syringe and its various associated parts as assembled or orientecl in the syringe for extruding use, and the terms "upper" and "upward"
are intended to refer to the opposite or heacl end of the same.
The invention is described hereinbelow wi-th reference to the accompanyincJ drawinys wherein:
FicJure 1 is a longitudinal sec-tion view oE a mixing/dispensincJ syrlnye unit of the invention in a pre-use configuration when pre-loaded with one component of a plasticizable mixture.
Fic3ure 2 is a plan view of a plunger rod used in combination with a dispensing syringe of the invention.
Figure 3 is a fragmentary longitudinal section view depictincJ a mixing/dispensing syringe oE the invention in D.N. 7314A
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combination with a filling syringe as the two would be con-figured in a loading or mixing combination.
Figure 4 is a fragmentary longitudinal view in partial section of a dispensing syringe of the invention as con figured during use to extrude a sem;-plastic mass from the barrel thereof.
Figure S is an enlarged view in transverse section of a slidable piston used within the barrel of the mixing/dis-pensing syringes of the invention.
Figure 6 is a perspective view of a package tray used to transport and store the syringe units of the invention.
Figure 7 is a top plan view of the package tray of Fig-ure 6 shown with the top cover of the tray removed and the mixing/dispensing syringe parts in position within the tray.
Figure 7A is a section view on line A-A of Figure 7.

The invention will now be described in detail with ref-erence to the foregoing figures where like numerals are used to designate like parts.
Figure 1 illustrates, in pre-use configuration, a mixing/dispensing syringe, generally indicated by refer-ence numeral 10, for use in extruding a semi-plastic mass, or a mass of paste-like consistency, whih comprises a bar-rel 11 having at the upper end ~hereof a finger grip 12 andclosed at the same end by a slidable piston 13. The barrel is filled with a solid~ or particulate, component 14 of a D.N. 7314A

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plasticizable mixture, which on admixture with a liquid component forms a semi-plastic mass. In its pre-use con-figuration, the lower end of the barrel is fitted with an adapter 15 which is frictionally engaged with the end of the syringe barrel and which has a Luer taper joint 16 for receiving an optional mating closure plug 17. The slidable piston 13 has a threaded opening 18 for positive inter-engagement with the threaded end 18' of a plunger rod lg, shown in Figure 2, having a thumb plate 20 at the upper end thereof. The slidable piston optionally has a vent hole 21, which is best seen in Figure 5, and which serves a purpose which will now be described with reference to Figure 3.
As shown in Figure 3, wherl it is desired to add a liquid component of the plasticizable mixture to the mixing syringe barrel 11, the closure plug 17 (if present) is re-moved, and a filling syringe 10' containing the liquid com-ponent 14' within the barrel thereof is attached to the mixing syringe 10 via Luer joint 16 in adapter 15. With the syrin~es thus joined, the contents of the filling syringe 10' are ejected into the barrel of the mixing syringe 10 where the li~uid component 14' from syringe 10' surrounds and fills the interstices within the particulate material 14, the air within barrel 11 being expelled through v~nt hole 21 as barrel 11 is filled. When the two components 14/14' have been thus admixed, the filling syringe 10' is detached from the adapter 15, and the D.N. 7314A

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closure plug 17 ~if used~ is reinserted into the Luer joint 16, thus restoring the syringe to the conflguration shown in Figure 1. The assembly is then maintained in this con-figuration until the plasticizable mixture sets up to the proper semi-plastic consistency and is thus ready for ex-trusion.
In an alternative means of filling the mixing syringe with a liquid component, the syringe barrel 10 would be only partially filled with the solid or particulate ~: 10 material 1~, and the piston ~ would be positioned approx-imately midway in the syringe barrelO The plunger 19 would be connected to the piston via the screw-threaded attachment 1~/18', the optional closure plug 17 would be removed from adapter 15, the end of the dispensing syringe with the attached adapter would be immersed in a container holding the desired liquid component, and the plunger/
piston would be withdrawn so as to draw the liquid into the syringe barrel ~or admixture with the solid co~lponent 1~.
The closure plug 17 can then, if desired, be reinserted in adapter 15 until the unit is ready for use. When the syringe is filled in this manner with the liquid comp~nent, it is clear that the vent hol.e 21 in the piston is not essential.

D.N. 7314A

After filling the syringe with the liquid component as described above, use of the assembly thereafter is seen with reference to Figure 4. Thus when it is desired to ex-trude the semi-plastic mass from the dispensing syringe barrel, the plunger rod 19 is engaged with the piston 13 via threaded connection 18/18', thus sealing vent hole 21 if present, the adapter/closure plug section 15~17 is removed from the end of the barrel, and the semi-plastic mass is forced from the barrel by downward pressure on thumb plate 20 of plunger 19.

Extrusion of the mass from the barrel is facilitated by providlng the bore of the barrel with a slight flare from the upper end to the lower, or exit, end thereof. The amount of Elare necessary to achieve this purpose would not be discernible in the drawings illustrating the invention, but desirably such flare, that is the difference in the in-side diameters between the upper and lower ends of the bar-rel, should be around 0.015 inches to 0.050 inches over a typical barrel length of around 3 to 4 inches. A parti-cularly preferred amount of flare is 0.025 inches over alength of about 3.5 inches.
Extrusion of the semi-plastic mass is further facil-itated by use of a piston of appropriate design and dimen-sions. A suitable piston is depicted in Figure 5. In or-der to insure a proper seal between the piston and the in-side wall of the barrel along its entire length, while not creating so much frictional drag as to render the piston D.N. 731~A

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inoperative, the piston is preferably ~olded with one or more annular shoulders, or sections of enlarged diameter, for example one shoulder 22 at the upper end of the piston and a second shoulder 22l at the lower end thereof. Both of these shoulders make sealing engagement with the inside barrel wall, while a section of diminished diameter 23 makes no frictional contact therewith.

The piston is made of a Elexible, or easily com-pressible, material such as a natural or synthetic elasto-mer or rubber, for example vinyl rubbers or butyl rubbers,including brominated or chlorinated butyl rubbers, or neo-prene. The diameter of the shoulders 22/22' is slightly larger than the greatest inside diameter of the barrel 11, but the sho~llders are compressible to the smaller diameter of the barrel while the piston is at the upper end of the barrel before use. Owing to the resiliency of the piston, the shoulders thus expand as the piston slides along the barrel towards the lower or exit end.
Although a piston with two shoulders 22/22' has been depicted in the accompanying drawings, it is to be under-stood that such double shouldered piston has been chosen solely for the purpose of illustration, and pistons having a single shoulder, or any multiple number of shoulders, are contemplated as being within the purview of the invention.
For example, a piston configured as shown in Figure 5, but D.N. 7314A
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lacking shoulder 22, would be fully operative in the prac-tice of the invention and is considered to be within the ambit of the inventive concept.
The syringes of the invention, when pre-loaded with a solid component of a plasticizable mixture, can be pre-packaged for shipment and storage in a package such as il-lustrated in Figures 6, 7 and 7A. The packages may consist of a thermoformed plastic tray 24 having two interior walls 25. The walls are formed with notches 26 which support the syringe body 10, together with its associated finger grip 12, adapter 15 and optional closure plug 17, and plunger rod 19. The tray can also be provided with a well 27 which can be used to temporarily store the closure plug 17 when the latter is removed either for direct filling of the lS syringe with the liquid component or for attachment of filling syringe 10' during the filling/admixing part of the use sequence all as described above. The tray is provided with a peripheral flange 28 to which a cover sheet 29, for ~ ` example of ~ylar~ or aluminum foil backed paper, can be affixed, for example, by heat sealing. A corner of the flange can be provided with a score line 30 to permit the corner of the tray to be broken off so as to provide a pull tab for peeling the cover sheet from the tray.
The syringes provided by the present invention find particular use in dispensing any multi-component semi-plastic mass including those prepared by addition of a li-quid component to another component with which it can be D.N. 7314A

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admixed in the barrel, i.e. either another liquid component or a solid or particulate component. Such uses would in-clude, for example, the extrusion of mixtures o fiber glass or powdered filler material with polyester resins, or two component glues such as resorcinol/formaldehyde qlues.
The syringes of the invention are particularly use~ul in the field of dental surgery and especially in alveolar ridge augmentation procedures in edentulous patients. In such patients, over a period of time the alveolar ridge un-dergoes gradual bone resorption with consequent diminutionin height of the alveolar ridge. This process in turn produces a condition whereby dentures must be remolded and fitted to a continuously changing gum shape~ The problem can be alleviated by restructuring the alveolar ridye with lS a material that is capable of bonding to osseus tissue, is non-resorbable and provides a matrix for new bone growth~
~Saterials which have been found useful for this purpose are certain ceramic materials, including especially hydroxyl-apatite and a mixture of hydroxylapatite and whitlockite.
The process for preparing hydroxylapatite and whitlockite and the use of these materials as dental restoratives, as described above, are disclosed in U.S. Patents 4,097,935 and 4,195t366, respectively.
In using syringes of the present invention in dental restorative procedures as described above, the barrel ll of the syringe would be filled with the powdered ceramic ma-terial, i.e. hydroxylapatite, a mixture of hydroxylapatite D.N. 731~A

and whitlockite or whitlockite alone. In one method of preparing the syringe for use, the dental surgeon would then use a separate blood samplin~ syringe 10' equipped with a detachable Luer needle/needle hub unit and withdraw a sample of the patient's blood from a vein. ~he needle/
needle hub would then be removed from the blood sampling syringe, the closure plug 17 would be removed from the mixing/dispensing syringe unit 10, and the blood sampling syringe would then be attached via the adapter 15 to the mixing/dispensing syringe 10. The blood would then be ejected from one syringe into the other. The emptied blood sampling syringe would then be removed, the closure plug replaced, the plunger rod connected to the piston, the syringe containing the ceramic/blood mixture set aside, and the blood allowed to coagulate.
In a second method of preparing the syringe for use in dental restorative procedures, the plunger rod would be attached to the piston, the closure plug 17 (if present) would be removed from the adapter, and the end of the syringe with the attached adapter would be immersed in a container holding the desired liquid component, for example any physiologically inert liquid such as saline or glucose, and the liquid drawn up into the syringe barrel by drawing backwards on the plunger rod. The closure plug would then be reattached to the adapter and the whole assembly set aside until ready for use.

D.N. 7314A

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When used in the manner described above for dental restorati~e procedures, it will be apparent that re-insertion of the closure plug and attachment of the plunger rod, 50 as to close off the vent hole 21 if present, after s the blood or other liquid component has been mixed with the ceramic material, effects a complete sealing of the syringe barrel thus protecting the contents from con-tamination.
Prior to preparation of the ceramic/blood coagulum or a ceramic/saline mixture as described above, the surgeon would intraorally prepare a mucoperiosteal tunnel through a vertical incision on the lateral aspect of the patient's jaw. The adapter/closure plug 15/17 would then be removed from the dispensing syringe, and the barrel of the syringe inserted through the incision and into the tunnel formed adjacent the alveolar ridge. By slowly withdrawing the syringe barrel while extruding the syringe contents by downward pressure on the plunger, the ceramic/blood mass would be deposited into the prepared mucoperiosteal tunnel adjacent the alveolar ridge. Ultimately the ceramic/blood mass will bond to the cortical bone thereby augmenting the alveolar ridge.
When used in alveolar ridge augmentation procedures as described above, the syringe barrel 11 can advantageously be supplied with appropriate indicia as an aid in deter-mining the amount and the rate of extrusion of the plastici~ed material from the barrel.

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~ l4 -Moreover, in the use of the syringes of the invention in alveolar ridge augmentation procedures, or in other u~es in which the mixing~dispensing syringe barrel contains a particulate material, it is advantageous to employ an adapter unit 15 having a constricted opening into the barrel so as to miminize the possibility that the parti-c~late material 14 would fall out of the barrel when the closure plug 17 is removed for attachment of the filling syringe 10' or for filling with a liquid component. Such constriction can be provided by means of a web 31, shown in Figures 1 and 3, having a narrow hole therethrough, across the throat o~ the Luer joint. The web can elther be formed as a unitary section of adapter 15, or it can be provided as a separate part to the adapter.
Moreover, it is also contemplated that the dispensing syringes of the invention can be used in combination with attachments to effect a measured and predetermined extru-sion rate of the contents. In one such means so contem-plated, the syringe, containing a plasticized solid/liquid mixture and fitted with the plunger, would be detachably secured to a syringe holder having a trigger-operated ratchetting interconnection means with the plunger rod, much the same as well known household caulking guns. Thus with each squeeze on the trigger, the plunger rod/pistGn would be advanced at a known and predetermined rate which could be indexed to indicia on the syrinye barrel as des-cribed above.

D.N. 7314A

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The syringes of the invention are suitably made of an appropriate plastic material which, when used in dental restorative processes, can be sterilized by autoclaving, gas or radiation. Thus the barrel, finger grip and clo-sure plug can be made of polyethylene or polypropylene,while the plunger rod is suitably made of styrene or nylon.
The adapter should preferably be made of a flexible ma-terial such as natural or synthetic elastomers or rubbers, for example vinyl or butyl rubbers, including brominated or chlorinated butyl rubbers. The tray package is preferably made of any thermoplastic material such as polystyrene.
It will be understood that, although preferred embod-iments have been described above in order to better il-lustrate the invention, alternative materials, forms and the like can be substituted for such aspects specifically described herein without either departing from the spirit of the invention or in any way adversely affecting the operability of the same.
For example, in the foregoing description, the means for venting air from the mixing/dispensing syringe barrel when used in combination with a filling syringe is illus-trated as a hole 21 in piston 13. An alternative means of achieving the same result is the use of a ramp or wedge shaped section axially aligned with the syringe barrel and extending laterally along only a part of the inside periphery of the barrel at the upper end thereof. During the filling sequence, the piston would lie at the top of D.N. 731~A

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the ramp, and an air passage between the piston and the sy-ringe barrel would be provided along either side of the ramp walls which would then be sealed off when the piston is moved downwards slightly thus displacing the piston from the ramp.
Furthermore, the means for making positive inter-con-nection between the plunger rod and the piston has been described herein, for purposes of illustration, in terms of a threaded connection 18/18'. However, any of various means well known in the art for making such inter-connec-tion that would be operative for the stated purpose, are considered to be within the ambit of the invention. Such alternative means of effecting inter-connection include, for example, a bayonet, or push-and-turn, connection, or a ball and socket connection in which a spheroid or elongate spheroid shape is used on the end of the plunger rod with a cavity of corresponding shape molded into the piston.
These, and other similarly effective inter-connecting means, are thus the full equivalents of the threaded inter-connection specifically exemplified herein.
Moreover, the means for connecting filling syringe 10'to mixing~dispensing syringe 10 i5 illustrated in the fore-going description as a Luer joint 16. The Luer joint is a particularly preferred means for effecting connection bet-ween the two syringes when used in dental restorativeprocesses, because blood sampling syringes are convention-ally equipped with a needle/needle hub unit which is de-.. . .

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tachable via a Luer joint. Thus blood sampling syringesso-equipped are readily adapted to the mixing/dispensing syringes of the invention for dental restorative use. F~ow-ever, other means of effecting inter-connec~ion, for ex-ample by use o a non-tapered joint, are also contemplated.
Also the invention has been described with particular emphasis on the mixing of a two-component solid/liquid plasticizable snixture. However, it will be apparent that the features oF the syringe provided by the invention will lend themselves to use with a preformed semi-plastic mass or to the mixing of any kind and number of components which, on admixture, form a semi-plastic mass, such as one solid with two or more liquids, or two or more liquids, one with the others.
It wilL also be appreciated that the mixing/dispensing syringe can also function solely as a dispensing syringe, 50 that the syringe can be marketed when pre-loaded with a semi-plastic mass. When used for such latter purpose, it will be obvious that the need for venting the barrel would be obviated.
Having thus described the invention and the advantages thereof, it is considered that the invention is to be broadly construed and limited only by the character of the following claims.

Claims (38)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A mixing/dispensing syringe for use in the extrusion of a wetted, semi-plastic mass, which comprises in combina-tion:
(A) a barrel of generally uniform wall thickness which is closed at its upper end by (B) a flexible piston slidable within the bore of said barrel and (C) a plunger rod removably attached to the piston, wherein the bore of said barrel is slightly flared from its upper to its lower end to provide relief of frictional resis-tance to extrusion.

2. A syringe according to claim 1 which includes a finger grip affixed to the upper end of said syringe barrel.

3. A syringe according to claim 2 which includes means for sealing the lower end of the syringe barrel.

4. A syringe according to claim 3 wherein said sealing means comprises a removable adapter and plug.

5. A syringe according to claim 4 wherein said plunger rod is attachable to the upper end of said piston by a screw-threaded connection.

6. A syringe according to claim 4 wherein said plunger rod is attachable to the upper end of said piston by a ball and socket connection.

7. A syringe according to claim 4 wherein said plunger rod is attachable to the upper end of said piston by a bayonet connection.

8. A syringe according to claim 5, 6 or 7 wherein said piston is provided with two shoulders for frictional engagement with the inside wall of said barrel.

9. A syringe according to claim 5, 6 or 7 wherein said piston is provided with one shoulder for frictional engagement with the inside wall of said barrel.

10. A syringe according to claim 4 wherein the syringe is provided with means for venting air from the syringe barrel.

11. A syringe according to claim 10 wherein said vent means comprises a hole through said piston.

12. A syringe according to claim 11 wherein said sealing means includes means for interconnecting a second syringe to said mixing/dispensing syringe.

13. A syringe according to claim 12 wherein said inter-connecting means comprises a Luer* joint.

14. A syringe according to claim 1, 3 or 8 wherein the flare of the bore of said barrel is from 0.015 to 0.05 inch over a barrel length of from 3 to 4 inches.

15. A syringe according to claim 1, 3 or 8 wherein the flare of the bore of said barrel is 0.025 inch over a barrel length of about 3.5 inches.

16. A dispensing syringe for use in the extrusion of a wetted semi-plastic mass, which comprises in combination:
(A) a barrel of generally uniform wall thickness which is closed at its upper end by (B) a flexible piston slidable within the bore of said barrel, and (C) a plunger rod for removable attachment to the piston, wherein the bore of said barrel is slightly flared from its upper to its lower end to provide relief of frictional resis-tance to extrusion and the barrel is pre-loaded with one compo-nent of a plasticizable mixture.

17. A syringe according to claim 16 wherein said pre-loaded component is a solid.

18. A syringe according to claim 17 wherein said solid component is a powdered ceramic material.

19. A syringe according to claim 18 wherein said powdered ceramic material is hydroxylapatite.

20. A syringe according to claim 18 wherein said powdered ceramic material is a mixture of hydroxylapatite and whitlock-ite.

21. A syringe according to claim 19 wherein the barrel thereof has indicia for determining the amount and the rate of extrusion of material therefrom.

22. A syringe according to claim 18 adapted for use in combination with an attachment to effect a measured and prede-termined extrusion rate, said attachment comprising a ratchet interconnection with the syringe plunger.

23. A package for shipping and storing a mixing/dispens-ing syringe for use in the extrusion of a wetted, semi-plastic mass, composed of a plasticizable mixture of two or more compo-nents, which comprises:
(I) a thermoformed plastic tray which is sealed over the open upper face by (II) a cover sheet, wherein said tray contains (III) a mixing/dispensing syringe which comprises in combin-ation:
(A) a barrel of generally uniform wall thickness which is closed at its upper end by (B) a flexible piston slidable within the bore of said barrel, and (C) a plunger rod for removable attachment to said pis-ton, wherein the bore of said barrel is slightly flared from its upper to its lower end to provide relief of frictional resis-tance to extrusion.

24. A package according to claim 23 wherein said barrel is pre-loaded with one component of a plasticizable mixture.

25. A package according to claim 24 wherein said preload-ed component is a solid.

26. A package according to claim 25 wherein said solid component is a powdered ceramic material.

27. A package according to claim 26 wherein said powdered ceramic material is hydroxylapatite.

28. A package according to claim 26 wherein said powdered ceramic material is a mixture of hydroxylapatite and whitlock-ite.

29. A package according to claim 26 wherein the barrel of said syringe has indicia for determining the amount and the rate of extrusion of material therefrom.

30. A package according to claim 29 wherein said syringe is adapted for use in combination with an attachment to effect a measured and predetermined extrusion rate, said attachment comprising a ratchet interconnection with the syringe plunger.

31. A method of extrusion of a wetted, semi-plastic mass, which method comprising:
mixing components to prepare the wetted semi-plastic mass in a barrel of a mixing/dispensing syringe, said syringe comprising a barrel of generally uniform wall thickness which is closed at its upper end by a flexible piston slidable within the bore of said barrel, and a plunger rod removably attached to the piston, wherein the bore of said barrel is slightly flared from its upper to its lower end to provide relief of frictional resistance to extrusion; and extruding the semi-plastic mass by way of a pressure exerted on the plunger rod from a lower end of the barrel.

32. A method of claim 31 wherein said barrel is preloaded with a solid component and a liquid component is introduced into the barrel so as to prepare the wetted semi-plastic mater-ial.

33. A method of claim 32 wherein the solid component is a powdered ceramic material selected from the group consisting of hydroxylapatite, whitlockite and a mixture thereof, and the liquid component is a physiologically acceptable liquid.

34. A mixing/dispensing syringe in combination with a wetted, semi-plastic mass, comprising:
(A) a barrel of generally uniform wall thickness which is closed at its upper end by (B) a flexible piston slidable within the bore of said barrel and providing a seal therebetween and the inside wall of the barrel along its entire length and (C) a plunger rod removably attached to said piston, wherein the bore of said barrel is slightly flared from its upper end to its lower end to provide relief of frictional resistance to extrusion.

35. A syringe according to claim 34, wherein said semi-plastic mass comprises a particulate ceramic material and a physiologically compatible liquid.

36. A syringe according to claim 35, wherein the particu-late ceramic material comprises hydroxylapatite.

37. A syringe according to claim 35 or 36, wherein the physiologically compatible liquid comprises blood.

38. A syringe according to claim 35 or 36, wherein the physiologically compatible liquid comprises saline.