Abstract
An application tip for dispensing a dental material has a tubular dispensing end made of a plastic material. The dispensing end being formed of a circumferential wall having a thickness T.sub.1 and which forms a dispensing opening of a diameter D.sub.i1 and having a diameter-to-thickness-ratio D.sub.i1:T.sub.1 at the opening which is 13 or greater. The wall thickness increases in a direction away from the opening. The application tip preferably facilitates appropriately depositing the dental material.
Claims
1. A system for dispensing a dental material, comprising: a cartridge with a chamber for holding the dental material; and an application tip adapted for removably coupling with a dispensing nozzle of the cartridge and dispensing the dental material in the chamber, wherein the application tip comprises a tubular dispensing end having an outer conical surface with a first diameter D.sub.o1 and a second diameter D.sub.o2, with D.sub.o2 greater than D.sub.o1, and an inner conical surface with a first diameter D.sub.i1 and a second diameter D.sub.i2, with D.sub.i2 greater than D.sub.i1, wherein the inner conical surface forms a conduit through the application tip to form a dispensing opening, the dispensing end being formed of a circumferential wall having a thickness T.sub.1 and which forms the dispensing opening of a diameter D.sub.i1, the dispensing end having a diameter-to-thickness-ratio D.sub.i1:T.sub.1 at the dispensing opening which is at least 13 or greater, wherein the wall thickness of the application tip increases in a direction away from the opening and wherein the wall and comprises: a first wall portion of a first plastic material selected among polyethylene (PE), polypropylene (PP), polyoxymethylene (POM), polybutadiene terephthalate (PBT), acrylonitrile-butadiene-styrene terpolymer (ABS), and polyamide (PA), and a second wall portion formed of a second plastic material selected from among a thermoplastic elastomer, silicone or rubber, wherein the first plastic material is less resilient than the second plastic material, and wherein the second wall portion is arranged adjacent the dispensing opening and the first wall portion is arranged further away from the dispensing opening.
2. The system of claim 1, wherein the application tip and the cartridge are formed in one piece.
3. The system of claim 1, wherein the application tip and the cartridge are formed in at least two separate pieces and being adapted for connecting with each other.
4. The system of claim 1, comprising a dental restorative material selected from among a composite, a bis-acrylic composite, and a glass ionomer.
5. The system of claim 1, wherein the inner conical surface forms a conduit through the application tip to form a first dispensing opening with a circular cross section and a first open area, and wherein the second plastic material is sufficiently resilient such that the dispensing end, when laterally deformed, forms a second dispensing opening with oval cross section and a second open area less than the first open area.
6. The system of claim 1, wherein the diameter D.sub.i1 is within a range of 1 mm to 2.5 mm and the thickness T.sub.1 is within a range of 0.05 mm and 0.19 mm.
7. The system of claim 1, having a predetermined breaking linkage in the transition between the first and second wall portions.
8. The system of claim 1, wherein the first and second wall portion are linked by a positive fit or friction fit.
9. The system of claim 1, wherein the wall has at least one slit extending from the opening in a direction away from the opening.
10. The system of claim 1, further comprising a piston which is movably arranged within the chamber for extruding the dental material.
11. The system of claim 10, further comprising a dispensing gun for removably receiving the cartridge and comprising a plunger for urging the piston forward for dispensing the dental material.
12. A system for dispensing a dental material, comprising: a cartridge with a chamber for holding the dental material; and an application tip adapted for removably coupling with a dispensing nozzle of the cartridge and dispensing the dental material in the chamber, wherein the application tip comprises a tubular dispensing end having an outer conical surface with a first diameter D.sub.o1 and a second diameter D.sub.o2, with D.sub.o2 greater than D.sub.o1, and an inner conical surface with a first diameter D.sub.i1 and a second diameter D.sub.i2, with D.sub.i2 greater than D.sub.i1, wherein the inner conical surface forms a conduit through the application tip to form a dispensing opening, the dispensing end being formed of a circumferential wall having a thickness T.sub.1 and which forms the dispensing opening of a diameter D.sub.i1, the dispensing end having a diameter-to-thickness-ratio D.sub.i1:T.sub.1 at the dispensing opening which is at least 13 or greater, wherein the wall thickness of the application tip increases in a direction away from the opening, and wherein the wall comprises: a first wall portion of a first plastic material chosen from polyethylene (PE), polypropylene (PP), polyoxymethylene (POM), polybutadiene terephthalate (PBT), acrylonitrile-butadiene-styrene terpolymer (ABS), and polyamide (PA), and a second wall portion formed of a second plastic material chosen from a thermoplastic elastomer, silicone or rubber, wherein the first plastic material is less resilient than the second plastic material, and wherein the first wall portion and the second wall portion are arranged in a circumferentially alternating manner.
13. The system of claim 12, further comprising a piston which is movably arranged within the chamber for extruding the dental material.
14. The system of claim 13, further comprising a dispensing gun for removably receiving the cartridge and comprising a plunger for urging the piston forward for dispensing the dental material.
Description
BRIEF DESCRIPTION OF THE FIGURES
(1) FIG. 1 is a cross-sectional view of an application tip according to an embodiment of the invention;
(2) FIG. 2 is a side view of the application tip shown in FIG. 1;
(3) FIG. 3 is a front view of the application tip shown in FIG. 1;
(4) FIG. 4 are cross-sectional views of an application tip according to a further embodiment of the invention;
(5) FIG. 5 are side views of a system for dispensing a dental material according to an embodiment of the invention;
(6) FIG. 6 is a cross-sectional view of a system for dispensing a dental material according to another embodiment of the invention; and
(7) FIG. 7 is a cross-sectional view of an application tip according to a still a further embodiment of the invention including
(8) FIGS. 7a,7b illustrating details of the application tip shown.
DETAILED DESCRIPTION OF THE INVENTION
(9) FIG. 1 shows a portion of an application tip 10 for dispensing a dental material. In particular the Figure shows a dispensing end 11 that extends along a longitudinal axis A. Although the longitudinal axis A in the example shown is straight, the skilled person will recognize that in another example the longitudinal axis may be curved without departing from the invention. The dispensing end 11 is formed of a circumferential wall 12 and forms a dispensing opening 13. The dispensing end 11 has a generally circular ring shaped cross-section. In the example the dispensing end has an outer conical surface and an inner conical surface. The inner conical surface forms at least part of a conduit through the application tip 10 and forms the opening 13 at one end. At the dispensing opening 13 the wall 12 tapers off to form a resilient front most end. In particular at the dispensing opening 13 the wall 12 has a thickness T.sub.1 and the opening has a diameter D.sub.i1. The diameter D.sub.i1 of the opening 13 and the wall thickness T.sub.1 form a predetermined diameter-to-thickness-ratio D.sub.i1:T.sub.1 at the opening 13. The diameter-to-thickness-ratio is determined to permit a deformation of the dispensing end in response of a one-dimensional force in a dimension lateral to the longitudinal axis as illustrated in FIG. 2. In the example the dispensing end 11 has a diameter-to-thickness-ratio (D.sub.i1:T.sub.1) within a range of 13 to 25. Further the wall thickness increases in a direction away from the opening 13. For example at a distance L from the opening 13 the wall thickness T.sub.2 is greater that the wall thickness T.sub.1 at the opening. This preferably provides the dispensing end 11 with a sufficient buckling resistance upon exposing the dispensing end 11 with a pushing force in a direction of the longitudinal axis A.
(10) FIG. 2 illustrates for the purpose of explaining the function and properties of the application tip the dispensing end 11 in a situation urged into an corner formed by two perpendicularly arranged surfaces 101, 102. A force U represents the force at which the dispensing end 11 is pushed toward the corner. Due to the resilient properties the dispensing end 11 generally conforms to the corner. In particular the dispensing end 11 flattens laterally to the longitudinal axis A in one dimension in response of the lateral forces F. Lateral forces F originate from the pushing force U in interaction with the surfaces 101, 102. Because of the flattening the dispensing end 11 is enabled to enter deeper into the corner than it would be enabled to without the flattening.
(11) FIG. 3 schematically illustrates the front most end of the dispensing tip 11 in the situation shown in FIG. 2, but from a perspective in a direction of the longitudinal axis A (see FIG. 2). The dispensing end 11 in the situation shown has a non-circular, in particular generally oval, ring shaped cross-section. This is indicated by the measures d1 and d2. The measures d1 and d2 are defined in the plane of the opening and in two perpendicularly arranged dimensions. The measure d2 is smaller than the measure d1. Further the measure d2 is smaller than the original diameter of the opening, and the measure d1 is greater than the original diameter of the opening. Accordingly relative to the circular cross-section illustrated in FIG. 1 the non-circular cross-section further results in an opening 13′ which is reduced in its open area. Therefore the dispensing end 11 further causes the flow resistance for the dental material to increase with increasing deformation (flattening) of the tip 11. It has been found that thus the control of the flow rate of the dental material into an corner, as it may for example be present at a tooth to be restored, can be facilitated. Further due to the flattening and conforming properties of the dispensing end 11 the dental material may be precisely placeable in the corner.
(12) In one example the diameter of the opening is about 1 mm and the wall thickness at the opening is about 0.05 mm, whereas in another example the opening is about 2.5 mm and the wall thickness at the opening is in a range of about 0.1 mm to 0.19 mm. It has been found that a dispensing end having diameter-to-thickness-ratio within the range of 13 to 25 at the opening provides a resilience of the dispensing end which permits it to conform into an corner in which it is manually pushed.
(13) FIG. 4 shows an application tip 20 having dispensing end 21 which comprises a first wall portion 21a and a second wall portion 21b. The first wall portion 21a is made of a first plastic material and the second wall portion 21b is made of a different second plastic material. The first plastic material is preferably less resilient than the second plastic material. Further the first plastic material may be selected from among polyethylene (PE), polypropylene (PP), polyoxymethylene (POM), polybutadiene terephthalate (PBT), acrylonitrile-butadiene-styrene terpolymer (ABS), and polyamide (PA). The second plastic plastic material may be selected from among a thermoplastic elastomer, silicone or rubber material. As shown the second wall portion 21b forms an opening 23 and is preferably formed of the second plastic material, whereas the first wall portion 21a further away from the opening 23 is formed from the first plastic material.
(14) In the example the application tip 20 has a predetermined breaking linkage 24 in the transition between the first and second wall portions 21a, 21b. In particular the first wall portion and the second wall portion are linked by a positive fit or friction fit. Thus the second wall portion 21b may be removable from the first wall portion. Thus the opening of the application tip may be increased, for example manually by a user.
(15) FIG. 5 shows a system 39 for dispensing a dental material. The system 39 has an application tip 30 which is adapted for removably coupling with a dispensing nozzle of a cartridge 35. The application tip 30 may be generally configured as described in the examples shown in FIGS. 1 to 4. Further the application tip 30 in the example has a retention mechanism 36 for retaining with the cartridge 35. The skilled person will recognize further retention mechanisms, like for example a thread or Luer-Lock™ connection.
(16) FIG. 6 shows a system 49 for dispensing a dental material. The system 49 has a cartridge 45 and an application tip 40. In the example the cartridge 45 and the application tip 40 are made in one piece. The cartridge 45 and the tip 40 may for example be monolithically formed of the same material, or formed by two-shot injection molding from two different materials. The cartridge 45 forms a chamber 45a for holding dental material. Further a piston 48 for extruding the dental material is movably and sealingly arranged within the chamber 45a. The cartridge 45 in the example has a coupling 47 which can be retained in a dispensing gun (not shown) for dispensing the dental material.
(17) FIG. 7 shows an application tip 50 having a dispensing end 51. The dispensing end 51 comprises first wall portions 51a and second wall portions 51b. The first wall portions 51a and the second wall portions 51b are arranged in a circumferentially alternating manner. The first wall portions 51a are made of a first plastic material and the second wall portions 51b are made of a different second plastic material. The first plastic material is preferably less resilient than the second plastic material. Further the first plastic material may be selected from among polyethylene (PE), polypropylene (PP), polyoxymethylene (POM), polybutadiene terephthalate (PBT), acrylonitrile-butadiene-styrene terpolymer (ABS), and polyamide (PA). The second plastic plastic material may be selected from among a thermoplastic elastomer, silicone or rubber material.
(18) FIG. 7a is a front view on the dispensing end 51 at an initial stage. At the stage shown in FIG. 7b the second wall portions 51b are compressed, for example in response of radial forces on the outside of the dispensing end 51. Thus the dispensing end may be adapted to penetrate in narrow cavities, for example a cavity in a tooth.
