Storing and dosing syringe

Abstract

The invention relates to a storing and dosing syringe (1) for storing and dispensing material, in particular for dental purposes, comprising an opaque syringe body (3) having an inner cavity (2) with a dispensing opening (5) and a plunger (4), provided in the cavity (2), for dispensing from the dispensing opening (5) material located in the cavity (2) between the plunger (4) and the dispensing opening (5), wherein a fastening region (6), surrounding the dispensing opening (5), is provided on the outside of the syringe body (3) for fastening a protective cap (10) for covering the dispensing opening (5) completely so that it is impermeable to light and there are no light gaps, characterized in that a two-part protective cap (10) made of opaque material is fastened to the fastening region (6) so that there are no light gaps, wherein - the one part (11) of the protective cap (10) is fastened to the fastening region (6) and the other part (12) of the protective cap (10) can be swivelled with respect to the one part (11) of the protective cap (10) between a closed position and an open position by means of a hinge (13), and - the parts (11, 12) of the protective cap (10) are designed in such a way that, in the closed position, they cover the dispensing opening (5) completely so that it is impermeable to light and there are no light gaps.

Description

Storage and dosing syringe

[0001] The invention relates to a storage and dosing syringe for storing and dispensing material, in particular for dental purposes.

[0002] Storage and dosing syringes, particularly for dental purposes, are known in the art. They are used, among other things, for the dispensing of dental restorative materials in portions during dental treatment.

[0003] Corresponding storage and dosing syringes have a storage volume for the restorative material. Using a dispenser or an actuating element integrated directly into the storage and dosing syringe, such as a threaded spindle, a piston is moved within the storage volume to dispense the contained restorative material through an opening. Depending on the restorative material, it can be introduced directly into the area of a tooth to be restored using a storage and dosing syringe and shaped there; alternatively, the restorative material is dispensed from the opening of the storage and dosing syringe and remains there largely stable in shape. It can then be picked up using a spatula and subsequently introduced into the area of a tooth to be restored using the spatula.

[0004] Regardless of the type of application, polymer-based restorative materials in accordance with EN ISO 4049:2019 ("Polymer-based restorative materials") are regularly used for the restoration of teeth. These restorative materials, which are plastically deformable in their initial state, can usually be cured or polymerized by irradiation with UV light in the wavelength range from 360 nm to 530 nm. Since the penetration depth of the UV radiation and thus the so-called Since the "polymerization depth" is limited to a few millimeters, the restoration material must be applied and cured in layers for extensive restoration of a tooth.

[0005] Since these restorative materials are cured by UV light, there is a risk that such a material may inadvertently begin to polymerize or harden during dental treatment due to exposure to daylight or artificial light, such as from treatment lamps. Restorative materials that are mixed together prior to the actual dental treatment—for example, to replicate the shade of the tooth being treated as closely as possible—are therefore temporarily stored in light-protected mixing containers.

[0006] For restoration materials where mixing is not required, as they essentially adopt the shade of the surrounding tooth material, e.g. by utilizing light interference (cf. e.g. document EP 3 613 402 A1), intermediate storage in a light-protected mixing container would constitute an unnecessary intermediate step. At the same time, corresponding restorative materials are often more sensitive to ambient light and thus pose an increased risk of unintentional polymerization and curing, which can complicate their use.

[0007] The object of the present invention is to create a storage and dosing syringe which is particularly advantageous for light-sensitive restoration materials.

[0008] This object is achieved by a storage and dosing syringe according to claim 1. Advantageous further developments are the subject of the dependent claims.

[0009] Accordingly, the invention relates to a storage and dosing syringe for storing and dispensing material, in particular for dental purposes, with an opaque syringe body comprising an internal cavity and a dispensing opening and a piston arranged in the cavity for dispensing material located between the piston and the dispensing opening in the cavity from the dispensing opening, wherein the dispensing opening is surrounded by a fastening area on the outside of the syringe body for fastening a protective cap for completely opaque and light-gap-free covering of the dispensing opening, wherein a two-part protective cap made of opaque material is fastened to the fastening area without a light gap, wherein - one part of the protective cap is attached to the fastening area and the other part of the protective cap can be pivoted between a closed and an open position relative to the first part of the protective cap via a hinge, and - the parts of the protective cap are designed in such a way that in the closed position they cover the discharge opening completely opaquely and without a light gap.

[0010] The storage and dosing syringe according to the invention is characterized in that, starting from a basic structure which is essentially known from the prior art, it comprises a protective cap which is fastened via a fastening area arranged on the syringe itself and which is designed in two parts in such a way that the other part of the protective cap which does not interact with the fastening area can be pivoted between an open and a closed position. In the closed position, the dispensing opening is covered completely opaquely and without a light gap, i.e. when the protective cap is in the closed position, light (particularly in the wavelength range relevant for the polymerization of the material in the storage and dosing syringe) does not penetrate the material or openings in the protective cap itself, nor is there a gap between the two parts of the protective cap and the protective cap and the fastening area through which light could penetrate. As a result, material in the area of the dispensing opening is also protected from unwanted polymerization by light when the protective cap is closed. Because the two parts of the protective cap can be pivoted, the storage and dosing syringe can be opened easily, even for short periods of time. During this time, the dispensing opening is accessible so that material can be dispensed there and, for example,to be picked up using a spatula or other dental tool. Since the protective cap can then be closed quickly and easily, the period during which material in the area of the dispensing opening is exposed to ambient light and therefore potentially polymerizes can be effectively limited.

[0011] It is preferred if the two-part protective cap is designed in such a way that, in the closed position and when moving between the open and closed positions, a predetermined minimum distance is maintained between the other part of the protective cap and the discharge opening in a direction perpendicular to the discharge opening. This ensures that, if there is material at the discharge opening and something protrudes from it, contact between the other part of the protective cap and the material at the discharge opening is avoided. As a result, the risk of contamination of the protective cap, which may prevent a light-gap-free closed position, is reduced. This minimum distance may depend, in particular, on the distance between the wall of the pivoting part of the protective cap opposite the hinge and the discharge opening.

[0012] It is particularly preferred if the stated minimum distance is at least 1 mm, preferably at least 2 mm, more preferably 3 mm, more preferably 4 mm. In this case, the minimum distance for most applications does not need to be more than 7 mm or 8 mm. With an appropriate minimum distance, it is possible, at least in the case of a fundamentally dimensionally stable material, to dispense material from the dispensing opening while the protective cap is still closed and to open the protective cap at a later time, with the material already dispensed then protruding from the dispensing opening so that it can be picked up, for example, with a spatula.In particular, a volume of material between 0.02 ml and 0.2 ml, preferably between 0.03 ml and 0.2 ml, and more preferably between 0.03 ml and 0.15 ml should be able to protrude from the dispensing opening without contact between the protruding material and the protective cap when the protective cap is opened. In this case, the protective cap only needs to be opened for the moment of collecting the already dispensed material. The effect of ambient light on the material can thus be further minimized.

[0013] The part of the protective cap attached to the fastening area can preferably be designed such that the dispensing opening protrudes beyond this part in the open position of the protective cap in such a way that a minimum distance between the spatula and the part of the protective cap is maintained when a spatula is properly wiped off the dispensing opening. This can reduce the risk of contamination of the protective cap, which can prevent a light-gap-free closed position. Alternatively, however, it is still possible for the part of the protective cap attached to the fastening area to be designed in such a way that the discharge opening does not protrude beyond this part when the protective cap is in the open position.

[0014] The hinge, by means of which the two parts of the protective cap are connected to one another, is preferably designed such that it is pretensioned in a first pivoting range, preferably extending to the closed position, such that it urges towards the closed position. In other words, the protective cap should close automatically as soon as the other part of the protective cap is moved far enough from the open position into the closed position that the hinge is in the first pivoting range in question. This effectively prevents the protective cap from being accidentally only partially closed.

[0015] Alternatively or additionally, it is possible to design the hinge in such a way that it is pre-tensioned in a second pivoting range, preferably extending to the open position, such that it urges towards the open position. By means of an appropriate design, it can be ensured that the other part of the hinge, when sufficiently opened, urges into the open position and is generally held there until it is closed again using sufficient force. By means of an appropriate design, the protective cap can be easily operated with the same hand that holds the storage and dosing syringe. In other words, one-handed operation of the protective cap is possible, so that the other hand can be used, for example, to guide a Spatula, with which material can be removed from the discharge opening of the storage and dosing syringe, is free.

[0016] If both the first and the second pivoting range are provided, it is preferred if they are essentially directly adjacent to one another.

[0017] It is preferred if the two-part protective cap comprises a closure for securing the two parts of the protective cap in the closed position. Accidental opening of the protective cap can be prevented by means of a corresponding closure. The closure can preferably be self-snapping in the closed position, i.e. the closure engages as soon as the protective cap is in the closed position. The closure should preferably be designed so that it can be opened with one hand, in particular by the hand holding the storage and dosing syringe. The closure can, for example, be designed as a snap-in closure in which a projection on one part of the protective cap in the closed position interacts in a form-fitting manner with an opening in the region of the other part of the protective cap, wherein the form-fitting engagement can be released by elastic deformation of at least one of the parts of the protective cap.

[0018] If a lock is provided to secure the protective cap in the closed position, a second pivoting range, as described above, can extend to the closed position. In this case, the protective cap pivots automatically into the open position as soon as the lock is released.

[0019] It is preferred if one part of the protective cap is fastened to the fastening area by force fit. This can be achieved, for example, by a cylindrical, conical or Cone-like design of the fastening area, onto which a correspondingly designed first part of the protective cap is placed. The protective cap can thus be attached to the syringe body quickly and easily in order to achieve a completely opaque and light-gap-free cover. This is particularly helpful if the syringe body or its dispensing opening is initially sealed, possibly hermetically, and the protective cap can only be put on after the seal has been removed. The protective cap can also be reused on another storage and dosing syringe after all of the material in the storage and dosing syringe has been dispensed. To ensure the desired frictional connection, the dimensions of the first part of the protective cap can be matched to the size of the fastening area according to the principle of a press fit.For example, a dimension characteristic of the frictional connection surfaces, such as a diameter, can be approximately 0.025 mm smaller in the protective cap than in the fastening area.

[0020] It is preferred if the hinge between the two parts of the protective cap is a film hinge. Such a hinge is light and small, so it does not interfere with the use of the storage and dosing syringe.

[0021] A further advantage of the force-fitting fastening of the protective cap to the fastening area and the design of the hinge as a film hinge is the resulting potential simplification of the production of the syringe body and / or protective cap. Overall, it is preferred if the syringe body and / or the two-part protective cap are each constructed in one piece, thus eliminating the need for joining. The syringe body and protective cap can preferably be manufactured using an injection molding process.

[0022] It is preferred if the piston can be moved in the direction of the dispensing opening by a manually operated spindle. The spindle can be permanently connected to the syringe body, for which the latter can have a suitable internal thread. The internal thread can be formed integrally in the syringe body or in a separate component fastened to the syringe body. The piston can be connected to the threaded spindle; however, this is not necessary. A handle (e.g. in the form of wings projecting laterally beyond the spindle) can be provided on the end of the spindle protruding from the storage and dosing syringe to enable easy operation of the spindle. The spindle can have markings by means of which the volume dispensed when the protective cap is closed can be read.Alternatively or additionally, the thread pitch of the spindle can be adapted to the material to be dispensed and the dimensions of the cavity in such a way that a predetermined volume is dispensed with one complete revolution of the spindle.

[0023] The cavity in the syringe body can have a volume of 0.1 ml to 0.3 ml for dispensing material, making it a storage and dosing syringe for a single treatment. However, the storage and dosing syringe according to the invention is particularly suitable for multiple treatments, which is why the cavity in the syringe body preferably has a volume of at least 1.5 ml to 4 ml.

[0024] The cavity of the syringe body can be cylindrical, so that the cavity has a constant cross-sectional area from the piston to the outlet opening. However, it is also possible for this cross-sectional area to increase, preferably continuously, towards the outlet opening. Suitable cross-sectional areas are between 15 mm 2 and 60 mm 2 , preferably between 20 mm 2 and 50 mm 2 , particularly preferably between 30 mm 2 and 40 mm 2 A suitable cross-sectional area increase is between 0 percent and 10 percent, preferably between 3 percent and 7 percent. The cross-sectional area preferably has a simple cross-section, which can be polygonal, but is preferably circular. The length of the cavity results from its preferred cross-sections and the preferred volume of material to be accommodated. The piston can be advanced at least to the extrusion opening, preferably a few tenths of a millimeter beyond.

[0025] To ensure the desired opacity of the protective cap, as well as the syringe body itself, in addition to selecting a suitable material, the wall thickness must be matched to the material. Furthermore, the syringe body must withstand the forces that occur when the material is extruded from the cavity. For a variety of plastic materials, it has been shown that a wall thickness in the area of the syringe body is between 0.5 mm and 6.0 mm, preferably between 0.5 mm and 5.5 mm. The wall thicknesses of the protective cap are at least 0.5 mm, preferably between 1.0 mm and 5.5 mm.

[0026] The surfaces on the inside when the protective cap is in the closed position are preferably brush-polished, similar to Ref. 18 according to VDI 3400. The surfaces on the outside when the protective cap is in the closed position preferably correspond to Ref. 27-30 according to VDI 3400. Of the external surfaces of the syringe body, the area of the discharge opening is preferably brush-polished.

[0027] The material for the syringe body and / or the protective cap, usually a plastic, e.g. a polyacetal or a polyamide, can be colored using black pigments. They can also be colored brightly and / or tooth-colored. Preferably, all parts of the syringe are made of a reusable plastic, in particular the same plastic, or a compostable or rapidly decomposing plastic, e.g., a polyester such as polylactide (PLA).

[0028] The material of at least the syringe body is preferably laser-markable. The syringe body can have one or more flat surfaces for marking. The syringe body can also have a polygonal cross-section, which prevents the syringe body from rolling away when placed on a flat surface.

[0029] A material for dental purposes is preferably arranged in the cavity of the syringe body. This is particularly preferably a polymer-based restorative material selected from dental composites.

[0030] A dental composite consists of at least one liquid organic component (often referred to as resin matrix), organic and / or inorganic particles, in particular selected from reinforcing and non-reinforcing filler particles and pigments, preferably inorganic filler particles which have at least one further organic component, and additives.

[0031] The at least one liquid organic constituent comprises at least monomers and preferably oligomers, prepolymers and / or polymers. Preferred monomers, oligomers and / or prepolymers are radically polymerizable. Preferred monomers, oligomers or prepolymers are di-, tri- or polyfunctional acrylic acid esters and / or methacrylic acid esters, more preferably comprising two or more urethane groups. Preferred additional organic components are silanols or Siloxanes .

[0032] A particularly preferred restoration material according to the invention contains 5 to 30 weight percent of liquid organic components and 70 to 95 weight percent of particles, as well as 0.001 to 5 weight percent of additives distributed between the liquid organic components and particles, based on 100 weight percent of the total composition. The additives comprise at least one photoinitiator.

[0033] A particularly preferred restoration material according to the invention has a solid consistency such that a vertical circular cylinder approximately 6 mm high and approximately 6.6 mm in diameter retains this shape with a tolerance of 0.1 mm at 23±2 °C for a period of at least 1 minute without processing, i.e., without the influence of any mechanical force (apart from the weight of the air column acting on it). This can be determined, for example, using a 3D scanner and image analysis.

[0034] The restorative material preferably comprises a single-shading composite in which the desired optical impression, i.e., the tooth color, is created primarily by utilizing light interference. Such a material is described, for example, in EP3613402A1.

[0035] The invention will now be described by way of example using a preferred embodiment with reference to the accompanying drawings. In the drawings: Figures 1a, b: various schematic representations of a first embodiment of a storage and dosing syringe according to the invention with different positions of the protective cap; and Figure 2a, b: schematic representations of a second embodiment of a storage and dosing syringe according to the invention.

[0036] Figure 1 shows a first exemplary embodiment of a storage and dosing syringe 1 according to the invention with the protective cap 10. Figure 1a shows a schematic external view of the storage and dosing syringe 1, with the protective cap 10 being shown in the closed position in the left-hand illustration and in the open position in the right-hand illustration. Similarly, the schematic sectional illustrations of the storage and dosing syringe 1 in Figure 1b show the closed position on the left and the open position on the right. In the detailed enlargement of the sectional view of the open position, the closed position is indicated by dashed lines.

[0037] The storage and dosing syringe 1 is used to store and dispense material (not shown) for dental purposes. The material is stored in a cavity 2 inside an opaque syringe body 3. The cylindrical cavity 2 is delimited on one side by a piston 4 and opens into a dispensing opening 5 on the opposite side. By moving the piston 4 in the direction of the dispensing opening 5, e.g. with the aid of a dispenser (not shown), the material can be dispensed from the dispensing opening 5. The syringe body 3 has a fastening area 6 surrounding the dispensing opening 5 in the region of the dispensing opening 5.The fastening area 6 is cylindrically shaped, while the syringe body 3 otherwise has a rectangular basic shape, resulting in flat surface sections 7 which prevent the storage and dosing syringe 1 from accidentally rolling away on a flat storage surface and are suitable for labeling, in particular by laser labeling.

[0038] A protective cap 10 is arranged on the fastening area 6.

[0039] The protective cap 10 is constructed in two parts, with one part 11 of the protective cap 10 being fastened to the fastening area 6 by a press fit and thus with a force fit. The connection between the one part 11 of the protective cap 10 and the fastening area is free of any light gap.

[0040] The other part 12 of the protective cap 10 is connected to the part 11 of the protective cap 10 fastened to the fastening area 6 via a hinge 13 designed as a film hinge. Via this hinge 13, the protective cap 10 can be pivoted between the closed position shown on the left in Figures 1a and 1b and the open position shown on the right.

[0041] The two parts 11, 12 of the protective cap 10 are designed and connected to each other via the hinge 13 in such a way that they cover the discharge opening 5 on the syringe body 3 completely opaquely and without a light gap.

[0042] The connection via the hinge 13 is further designed in such a way that in the closed position and when moving between the open and closed positions, a minimum distance of at least 2 mm is maintained between the pivotable part 12 of the protective cap 13 and the discharge opening 5 in the direction perpendicular to the discharge opening 5. This minimum distance, which results from the position of an edge of the pivotable part 12 of the protective cap relative to the discharge opening 5 during pivoting, which is indicated in the detailed illustration in Figure 1b by the dash-dot line 90, results in the volume 91 indicated by dotted lines in the detailed illustration of Figure 1b, which already when the Protective cap 10 can be moved by suitable movement of the piston 4 material from the cavity 2 of the syringe body 3, in order to then be picked up immediately from there by a spatula or the like after the protective cap 10 has been opened. As can be seen from the detailed illustration in Figure 1b, the dispensing opening 5 protrudes beyond the part 11 of the protective cap 10 which bears against the fastening area 6. As a result, the risk is reduced that material will reach this part 11 of the protective cap 10 when the spatula is wiped off the dispensing opening 5 when picking up material from the volume 91, where it could prevent the light-impermeable and light-gap-free closed state.

[0043] The protective cap 10 comprises a closure 14, with which the pivoting part 12 of the protective cap 10 can be secured to the other part 11 in the closed position. For this purpose, the fixed part 11 comprises a projection 15, which a tab 16 arranged on the pivoting part 12 of the protective cap 10 encompasses in the closed position. The projection 15 and tab 16 are coordinated with one another such that the closure 14 snaps shut automatically when the pivoting part 12 of the protective cap 10 is moved into the closed position. The closure 14 can be opened by lifting the tab 16.

[0044] The hinge 13 is also designed such that it essentially pushes toward the open position across its entire pivoting range, from the closed position to the open position. In other words, the protective cap 10 swings open on its own unless the two parts 11, 12 of the protective cap 10 are held in the closed position by the closure 14.

[0045] The syringe body 2 and protective cap 10 are each manufactured as a single piece using an injection-molded process. To achieve the desired opacity, the plastic used is mixed with suitable pigments.

[0046] Figure 2a, b shows a second embodiment of a storage and dosing syringe 1 according to the invention, which is similar in basic construction to that of Figure 1a, b, for which reason reference is made to the above explanations in this regard.

[0047] The storage and dosing syringe 1 comprises, in addition to the syringe body 2 and the protective cap 10, also a spindle 20 which is guided in an internal thread 8 on the syringe body 2 and rests against the piston 4 with the end inserted into the syringe body 2. By turning the spindle 20 using the handle 21 provided for this purpose at the free end of the spindle 20, the piston 4 can be moved in the direction of the dispensing opening 5. With each complete revolution of the spindle 20, a predetermined volume of material is pushed out of the dispensing opening 5, so that a desired volume can be dispensed by selecting the appropriate number of revolutions of the spindle 20.

Claims

Patent claims 1. Storage and dosing syringe (1) for storing and dispensing material, in particular for dental purposes, with an opaque syringe body (3) comprising an internal cavity (2) with a dispensing opening (5) and a piston (4) arranged in the cavity (2) for dispensing material located between the piston (4) and the dispensing opening (5) in the cavity (2) from the dispensing opening (5), wherein the dispensing opening (5) is surrounded by a fastening area (6) on the outside of the syringe body (3) for fastening a protective cap (10) for completely covering the dispensing opening (5) in a light-impermeable and light-gap-free manner, characterized in that a two-part protective cap (10) made of opaque material is fastened to the fastening area (6) in a light-gap-free manner, wherein - one part (11) of the protective cap (10) is fastened to the fastening area (6) and the other part (12) of the protective cap (10) can be pivoted between a closed and an open position relative to the one part (11) of the protective cap (10) via a hinge (13), and - the parts (11, 12) of the protective cap (10) are designed such that in the closed position they cover the dispensing opening (5) completely opaquely and without a light gap.

2. Storage and dosing syringe according to claim 1, characterized in that the two-part protective cap (10) is designed in such a way, that in the closed position and when moving between the open and closed positions, a predetermined minimum distance is maintained between the other part (12) of the protective cap (10) and the discharge opening (5) in the direction perpendicular to the discharge opening (5).

3. Storage and dosing syringe according to claim 1, characterized in that the at least one minimum distance is at least 1 mm, more preferably 2 mm, more preferably 3 mm.

4. Storage and dosing syringe according to one of the preceding claims, characterized in that the part attached to the fastening area (6) (11) of the protective cap (12) is designed such that the dispensing opening (5) protrudes beyond this part (11) in the open position of the protective cap (10) in such a way that when a spatula is properly wiped off the dispensing opening (5), a minimum distance between the spatula and one part (11) of the protective cap (10) is maintained.

5. Storage and dosing syringe according to one of the preceding claims, characterized in that the hinge (13) is designed such that it is pretensioned in a first pivoting range, preferably extending to the closed position, such that it urges in the direction of the closed position.

6. Storage and dosing syringe according to one of the preceding claims, characterized in that the hinge (13) is designed such that it can be second pivoting range, which preferably extends to the open position, is pretensioned in such a way that it pushes towards the open position.

7. Storage and dosing syringe according to one of the preceding claims, characterized in that the two-part protective cap (10) comprises a closure (14) for securing the two parts (11, 12) of the protective cap (10) in the closed position, wherein the closure (14) is preferably self-snap-together in the closed position.

8. Storage and dosing syringe according to one of the preceding claims, characterized in that one part (11) of the protective cap (10) is force-fittingly fastened to the fastening area (6).

9. Storage and dosing syringe according to one of the preceding claims, characterized in that the hinge (13) is a film hinge.

10. Storage and dosing syringe according to one of the preceding claims, characterized in that the syringe body (3) and / or the two-part protective cap (10) are each manufactured in one piece by injection molding.

11. Storage and dosing syringe according to one of the preceding claims, characterized in that the piston (4) can be moved in the direction of the discharge opening (5) by a manually operable spindle (20).

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