Dental article with application device, lubricant composition and dental material

Abstract

The invention relates to a dental article comprising an application device (20) with a compartment (30) having an inner surface (31), a piston assembly (40) moveably located in the compartment (30), the piston assembly comprising a piston body (41), a seal A (42) at the front end of the piston body, seal A having one or more gaps (43), a seal B (44) spaced apart from seal A, a collection reservoir (45) suitable for collecting a lubricant composition during the dispensing of a dental material, a dispensing section (50) located at the distal end of the compartment, a lubricant composition (60) located on the inner surface of the compartment, and a dental material (70) being located in the compartment in contact with the lubricant composition.

Description

[0001] DENTAL ARTICLE WITH APPLICATION DEVICE, LUBRICANT COMPOSITION AND

[0002] DENTAL MATERIAL

[0003] Field of the Invention

[0004] The invention relates to a dental article comprising an application device, a lubricant composition and a dental material.

[0005] The application device comprises a tube-shaped compartment, a dispensing section and a piston assembly with a collection reservoir for collecting the lubricant composition during the dispensing of a dental material.

[0006] Background

[0007] Dental materials, in particular dental composite material, are widely used for restoring defect dental tooth structure in the mouth of a patient.

[0008] Dental materials often contain polymerizable (meth)acrylate components, filler and an initiator system suitable for hardening the dental material by applying radiation.

[0009] In particular, dental composite materials typically have a high filler load which is needed for achieving adequate mechanical properties after hardening of the material.

[0010] The high filler load usually results in a high viscous material which needs to be adequately stored before use to avoid an undesired polymerization.

[0011] As suitable packaging devices screw syringes and so-called composite capsules are often proposed. Both packaging devices allow the extrusion of the stored dental composite material through a nozzle to a dental surface to be treated.

[0012] However, due to the high viscosity of the dental composite material high extrusion forces are typically required.

[0013] The high extrusion forces can either be achieved by using a screw thread with an adequate piston or by using a suitable applier.

[0014] Packaging devices for storing dental material are described in various patent documents.

[0015] US 5,603,701 (Fischer) describes a syringe apparatus for delivering solid, yet pliable materials, such as dental composites. The syringe apparatus comprises an unthreaded barrel means for containing the material. The unthreaded barrel means has an inlet end, an outlet end, and an enlarged finger grip at the inlet end. The syringe apparatus also comprises means for slidably engaging the finger grip of the barrel means, the engaging means having a threaded throughbore. The syringe apparatus further comprises a plunger means for movement through the barrel means.

[0016] US 4,863, 072 (Perler) describes an apparatus for the delivery of light-curable composite dental filling material comprises a tubular composite reservoir, plunger and slider. The slider is free to move longitudinally along the reservoir but is matingly mounted to facets on the outside surface of the reservoir to prevent angular movement of the slider relative to the reservoir. The plunger consists of a shaft threaded to mate with the threaded inside diameter of the composite reservoir.

[0017] US 11,351,009 B2 (Clark et al.) describes a capsule for use in a dental composite dispenser, comprising a hollow body with a wall defining an interior space of the body, the body including a proximal end and a distal end having a dispensing orifice; a first composite resin positioned in the interior space of the body; and a second composite resin positioned in the interior space of the body, wherein the first composite resin has a first viscosity, the second composite resin has a second viscosity less than the first viscosity, wherein no barrier is positioned between the first composite resin and the second composite resin, wherein the second composite resin is configured to be extruded through the dispensing orifice prior to the first composite resin, and wherein the first composite resin and the second composite resin are in contact before use of the capsule in the dental composite dispenser.

[0018] US 2022 / 023538 Al (Boehm et al.) describes a syringe for storing and dispensing a first and a second component of a material. The syringe has a first chamber containing the first component and a second chamber containing the second component. The syringe further has an empty blank chamber that spaces the first and second chamber from each other.

[0019] US 2016 / 296962 Al (Maxa) describes devices for dispensing compositions, the device having a tip (72) including an inner tapered funnel portion (74); a hollow barrel (84) including an outer tapered surface portion (86), an inner surface, an open front end, and an open back end opposite the front end; and a piston (16), where the outer tapered surface portion of the barrel aligns and releasably engages with the inner tapered funnel portion of the tip, and where the piston is in sliding engagement with the barrel.

[0020] Similarly, appliers for dispensing dental composite materials from packaging devices are also described in the patent literature.

[0021] US 6,790,037 Bl (Orecchia) describes a viscous material dispenser for applying a viscous dental material from a capule, cartridge or capsule. The dispenser includes a locking mechanism mounted on the syringe type dispenser to securely retain the capule, cartridge or capsule within the syringe type dispenser while the viscous material is being applied from the syringe type dispenser.

[0022] US 10,016,257 B2 (Pauser) describes a pen-like dispenser for dispensing a dental material has a handle and a cover which are attached for rotation relative to each other about a longitudinal axis of the dispenser, and a cartridge for holding the dental material and a screw plunger for extruding the dental material from the cartridge by screwing action

[0023] For reducing the application force, it has also been suggested to warm the dental composite materials and thus reduce the viscosity.

[0024] Devices and processes for warming dental composite materials are e.g., described in WO 2021 / 053408 Al (3M), WO 2020 / 025485 Al (Voco). Further, it was observed that the application of high forces to high viscous dental composite materials may cause a so-called “run-on” of the dental composite material even after the dispensing is completed, because during the extrusion process the high viscous dental composite material often expands the cartridge in length and diameter and needs an appropriate time to relax after the extrusion force has been applied by the screw / thread.

[0025] Common to all devices is that the dispensing of the dental material from those devices is often cumbersome as the dental material is typically sticky and high viscous.

[0026] For reducing the friction during the dispensing process it has also been proposed to apply a lubricant on the inner surface of the device.

[0027] However, none of the solutions known to the practitioner so far is fully satisfying. of Invention

[0028] There is still a need for an improved dental article or application device suitable for storing and dispensing dental materials.

[0029] In particular there is a need for an application device for storing and dispensing dental materials having a high viscosity.

[0030] Thus, one object of the invention is to provide an article or device which allows the dispensing of in particular high viscous dental materials more easily, preferably with less exertion.

[0031] Ideally, it should be possible to dispense the dental material from the article or the device without the need for supplemental gadgets.

[0032] It was found that during the dispensing of dental material from a device containing a lubrication material on its inner surface, the lubrication material often starts accumulating at the distal end of the device.

[0033] The accumulated lubrication material is then dispensed from the device together with the dental material. This may have an undesired impact on the overall performance and physical properties of the dental material after hardening.

[0034] Thus, it would also be desirable that the dispensing of the dental material from the application device does not negatively affect the overall performance of the dental material during use.

[0035] One or more of these objects are addressed by the present invention.

[0036] In one aspect the invention features a dental article as described in the present text and claims. This dental article (10) comprise an application device (20) with a compartment (30) having an inner surface (31), a piston assembly (40) moveably located in the compartment (30), the piston assembly comprising a piston body (41), a seal A (42) at the front end of the piston body, seal A having one or more gaps (43), a seal B (44) spaced apart from seal A, a collection reservoir (45) suitable for collecting a lubricant composition during the dispensing of a dental material, a dispensing section (50) located at the distal end of the compartment, a lubricant composition (60) located on the inner surface of the compartment, and a dental material (70) being located in the compartment in contact with the lubricant composition.

[0037] In another aspect, the invention relates to a process for producing a dental article as described in the present text and claims.

[0038] A further aspect of the invention is directed to a process for dispensing the dental material from the dental article as described in the present text and claims.

[0039] The invention also relates to a kit of parts comprising the dental article and the following items alone or in combination: dental curing light, dental etchant, dental primer, dental adhesive, dental cement as described in the present text and claims.

[0040] Unless defined differently, for this description the following terms shall have the given meaning:

[0041] A “dental article” means an article which is to be used in the dental or orthodontic field, especially a dental article being suitable for supporting the restoration of a dental tooth.

[0042] A “dental material” means a material intended to be used in dental practice. More particularly, dental materials include dental composite materials, dental cements, dental adhesives, dental crown and bridge materials. Those materials are typically used for restoring a dental tooth.

[0043] Dental materials are typically hardenable compositions, which can be hardened at ambient conditions, including a temperature range of 15 to 50°C or 20 to 40°C within a time frame of 30 min or 20 min or 10 min. Higher temperatures are not recommended as they might cause pain to the patient and may be detrimental to the patient's health.

[0044] Dental materials are typically provided to the practitioner in comparable small volumes, that is volumes in the range of 0.1 to 100 ml or 0.5 to 50 ml or 1 to 30 ml.

[0045] A “dental restorative material” means a material which is to be used for restoring a dental tooth. Examples of dental restorations include crowns, bridges, inlays, onlays, veneers, facings, copings, crown and bridged framework, and parts thereof.

[0046] A “hardenable or curable or polymerizable component” is a component which can be cured or solidified in the presence of a photo-initiator by radiation-induced polymerization or by using a redox-initiator system. A hardenable component may contain one, two, three or more polymerizable groups. Typical examples of polymerizable groups include unsaturated carbon groups, such as a vinyl group. An example is a (methyl)acrylate group.

[0047] As used herein, “hardening” or “curing” a composition are used interchangeably and refer to polymerization and / or crosslinking reactions including, for example, photo -polymerization reactions and chemical-polymerization techniques (e. g., ionic reactions or chemical reactions forming radicals effective to polymerize ethylenically unsaturated compounds) involving one or more materials included in the composition.

[0048] An “initiator or initiator system” is a component or a combination of components being able to start the curing process of a hardenable component. “Proximal” means a part of a body or article that is closer to the practitioner during use. For a syringe assembly, the rear end receiving the plunger is the proximal end of the syringe assembly. “Distal” means the opposite of proximal. For a syringe assembly, the front or dispensing end is the distal end of the syringe assembly.

[0049] As used herein, “a”, “an”, “the”, “at least one” and “one or more” are used interchangeably. Also herein, the recitations of numerical ranges by endpoints include all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0050] Adding an “(s)” to a term means that the term should include the singular and plural form. E.g. the term “additive(s)” means one additive and more additives (e.g. 2, 3, 4, etc.).

[0051] Unless otherwise indicated, all numbers expressing quantities of ingredients, measurement of physical properties such as described below and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about”.

[0052] The terms “comprise” or “contain” and variations thereof do not have a limiting meaning where these terms appear in the description and claims. “Consisting essentially of’ means that specific further components can be present, namely those which do not materially affect the essential characteristic of the article or composition. “Consisting of’ means that no further components should be present. The term “comprise” shall include also the terms “consist essentially of’ and “consists of’.

[0053] Fig. 1 is a perspective view of the dental article described in the present text.

[0054] Fig. 2 is a schematic enlarged cross-section of a portion of the dental article described in the present text.

[0055] Figs. 3 A-D show different embodiments of piston assemblies.

[0056] Figs. 4A-D schematically shows the working principle of the dental article of the present text. It is shown how the lubricant composition flows from the inner surface of the compartment to the collection reservoir of the piston assembly during the dispensing of the dental material.

[0057] The dental article described in the text has a couple of advantageous properties.

[0058] The dental article is not only suitable for storing dental materials but also facilitates the dispensing of the dental material stored in the dental article during use.

[0059] The lubricant composition on the inner surface of the compartment is suitable for reducing the friction of the dental material on the inner surface of the compartment.

[0060] This enables the dispensing of the dental material from the article without the need of supplemental equipment such as caulk-gun like application devices. The collection reservoir helps to reduce or avoid the contamination of the dental material with the lubricant composition during the dispensing process in that the lubricant composition is collected during the dispensing process in the collection reservoir.

[0061] Since the lubricant composition has a much lower viscosity than the dental material, it can flow more easily through gaps in the piston assembly.

[0062] The first seal (seal A) of the piston assembly is typically a gap seal that has a low resistance for the lubricant composition to pass it but has a high resistance for the dental material. This contributes to the lubricant composition flowing into the collection reservoir during the dispensing of the dental material.

[0063] The dental article described in the present text typically works as follows:

[0064] The pressure needed for the dental material to pass the gap seal (seal A) at the distal end of the piston assembly is much higher than the pressure needed for passing the dispensing section at the distal end of the dental article.

[0065] Hence the dental material can easily be dispensed from the dental article in the distal direction without running the risk that a part of the dental material is flowing backward through the gap seal in proximal direction.

[0066] It has been found that at the outlet restriction of the dental article (that is at the dispensing section) the dental material is often forming a kind of plug during the dispensing process of the dental material that reduces the amount of lubricant composition exiting the tube-shaped compartment together with the dental material in the distal direction of the dental article.

[0067] This may lead to an accumulation of the lubricant composition in the area of the dispensing section before the outlet restriction of the dental article.

[0068] However, once seal A of the piston assembly is reaching the area of the dispensing section during the dispensing of the dental material, the lubricant composition starts flowing backwards across the one or more gaps in seal A into the collection reservoir of the piston assembly.

[0069] Due to the design of the piston assembly, the pressure which would be needed to extrude the lubricant composition through the restriction of the dental article in distal direction is higher than the pressure needed for forcing the lubricant composition to flow backwards into the collection reservoir of the piston assembly.

[0070] The collection reservoir behind the gap seal allows the lubricant composition to be pressed inside the collection reservoir of the piston assembly. The volume of the collection reservoir of the piston assembly is typically capable to take on the complete volume of the lubricant composition.

[0071] The collection reservoir may also have a connection to a hollow area in the inside of the piston body.

[0072] Behind the collection reservoir there is a tight seal (seal B) preventing the lubricant composition from flowing into the gap between an optional piston rod and the inner wall of the compartment; thus, preventing or reducing the risk that the lubricant composition exits the dental article at the proximal end.

[0073] The inside of the piston assembly typically has a ventilation opening at the proximal site allowing air, which might be present, to exit the piston assembly. The ventilation opening can have different shapes, e.g., circular or rectangular, wherein a circular opening is often preferred.

[0074] The presence of a ventilation opening prevents or reduces the risk of a build-up of air pressure in the piston assembly or compartment of the application device that could otherwise lead to a run on of the dental material or a “spongy -like” feeling when exerting pressure on the piston assembly through an optional piston rod or even would prevent the lubricant composition from flowing into the collection reservoir of the piston assembly.

[0075] If present, the ventilation opening provides a sufficiently high resistance to the lubricant composition to prevent the lubricant composition from exiting the piston assembly through the ventilation opening in proximal direction.

[0076] The invention is directed to a dental article comprising an application device, a dental material and a lubricant composition.

[0077] The application device typically comprises a compartment, a piston assembly, and a dispensing section.

[0078] The compartment comprises an inner surface.

[0079] The compartment can be further characterized by having a proximal end, a distal end, an inner diameter and an axial length.

[0080] The length of the compartment essentially defines the volume of packaging device which is available for receiving the dental material to be stored in the packaging device.

[0081] The volume of the compartment is typically in a range of 0.1 ml to 100 ml or 0.5 to 50 ml or 1 to 30 ml.

[0082] The inner diameter of the compartment is typically in the range of 2 to 25 mm.

[0083] The outer diameter of the compartment is typically in the range of 4 to 30 mm.

[0084] Thus, the wall-thickness of the compartment is typically in the range of 0.5 to 2 mm.

[0085] The ratio of length to inner diameter of the compartment is typically in the range of 25 / 1 to 3 / 1.

[0086] Such a ratio was found to be useful as it provides a good balance between the diameter available for transferring force to the dental material during the extrusion process and handling of the dental product by the practitioner.

[0087] The compartment is typically tube-shaped.

[0088] Overall, the application device may have the shape of a syringe with a tubular hollow barrel with a front end and a rear end opposite the front end. Within the compartment, in particular at the rear or proximal end of the compartment, a piston assembly can be inserted, which is in sliding engagement with the inner surface of the compartment. That is, the piston assembly is movable within the compartment.

[0089] The piston assembly is also for sealing the rear end of the compartment and for transferring pressure to the dental material during the extrusion or dispensing process.

[0090] The piston assembly comprises a cylindrical piston body.

[0091] The piston body comprises two seals, seal A and seal B.

[0092] Seal A is located at the front or distal end of the piston body.

[0093] Seal B is spaced apart from seal A in proximal direction of the dental article.

[0094] Seal A comprise one or more gaps.

[0095] The one or more gaps have a width WSA in the direction of the inner surface of the tube-shaped compartment.

[0096] Width WSA may be in a range of 0.05 to 0.50 mm or 0.08 to 0.30 mm.

[0097] The gaps are typically circumferentially arranged.

[0098] The one or more gaps may have the shape of a circumferential slit, a gear rim or an intermitted gap seal.

[0099] The piston assembly and / or seal B typically comprise in addition a ventilation opening.

[0100] The ventilation opening is for enabling air to escape from the tube-shaped compartment during the dispensing of the dental material.

[0101] As the ventilation opening is for air only, the diameter of the ventilation opening DVo is small, e.g., in a range of 0.05 to 0.3 mm.

[0102] The ventilation opening is typically in connection with the collection reservoir.

[0103] The ventilation opening is typically arranged in seal B. However, the ventilation opening may also be arranged in another section of the piston assembly.

[0104] The piston assembly may further comprise a pin at the distal end.

[0105] The pin may help the practitioner to visually determine the dispensing status of the dental material in the compartment. When the pin is appearing in the area of the dispensing section essentially all of the dental material has been dispensed.

[0106] The presence of a pin may also help to reduce waste volume remaining in the dispensing section.

[0107] The pin may have the shape of a conus or cylinder. The axial length of the conus or cylinder may correspond to or essentially correspond to the axial length of the dispensing section.

[0108] Typically, the axial length of the pin is in a range of 2 to 20 mm or 5 to 15 mm.

[0109] The piston assembly further comprises a collection reservoir.

[0110] The collection reservoir is suitable for collecting the lubricant composition which is located on the inner surface of the compartment, during the dispensing of the dental material. The collection reservoir is accessible through the one or more gaps in seal A and thus in connection with the compartment of the application device.

[0111] The collection reservoir has a volume VCR, which is typically larger than the volume VLC of the lubrication composition.

[0112] Volume VCR is typically in a range of 0.001 to 20 ml, or 0.005 to 5 ml.

[0113] The collection reservoir may comprise one or more portions which are in connection with each other, wherein “connection with each other” means that the lubricant composition is able to flow during the dispensing process from one portion to the next portion of the collection reservoir.

[0114] A portion of the collection reservoir can be located in a hollow area of the piston body.

[0115] Alternatively or in addition, a portion of the collection reservoir can be located in an area between seal A and seal B.

[0116] Alternatively or in addition, a portion of the collection reservoir can be located in a piston rod (or plunger) having a hollow area which is in connection with the collection reservoir a hollow area of the piston body.

[0117] If present, the piston rod is connected to or is attachable to the proximal end of the piston body. Once attached to the piston assembly, the piston rod should remain in its attached position during use of the dental article.

[0118] If desired, the piston assembly and the piston rod, if present, are made of one part.

[0119] The dental article typically also comprises a dispensing section through which the dental material can be dispensed.

[0120] The dispensing section is located at the distal end of the compartment.

[0121] The dispensing section may be tapered and / or comprises a dispensing nozzle.

[0122] The dispensing nozzle may be releasably engaged or attached to the compartment.

[0123] The dispensing section may comprise a tapered funnel section at the front end. The tapered funnel section may comprise a conical inner surface.

[0124] The dental article further comprises a lubricant composition.

[0125] During storage the lubricant composition is located on the inner surface of the tube-shaped compartment.

[0126] Typically, the thickness of the layer of the lubricant composition is in a range of 1 to 500 pm.

[0127] If desired, the thickness of the layer can be determined with a microscope by cutting the packaging device and inspecting the interface of the dental material and the inner wall of the compartment.

[0128] The viscosity of the lubricant composition is typically in the range of 1 to 10,000 Pa*s or 10 to 1,000 Pa*s or 20 to 800 Pa*s at a temperature of 25°C and a shear rate of 10 s’1, wherein a range of 10 to 1,000 Pa*s or 20 to 800 Pa*s is sometimes preferred. Such a viscosity was found to be useful as it facilitates the coating of the inner surface of the compartment of the packaging device during production.

[0129] The viscosity is sufficiently low for enabling a homogenous coating and sufficiently high for reducing the risk that the lubricant composition drops or flows down from the inner surface of the compartment of the packaging device.

[0130] Regarding its chemical properties and / or composition, the lubricant composition is compatible with the dental material.

[0131] The lubricant composition may comprise a monomer with an ethylenically unsaturated group and optionally a filler.

[0132] The monomer typically has a molecular weight in the range of 130 to 1,200 g / mol or 130 to 1,000 g / mol or 130 to 800 g / mol or 130 to 600 g / mol.

[0133] The lubricant composition may comprise (meth)acrylate monomers, that is, components which can be copolymerized with other polymerizable components which are typically present in a dental material.

[0134] The lubricant composition may further comprise fdler. One or more fillers can be present. Adding a filler can be beneficial e.g., for adjusting the rheological properties like viscosity.

[0135] The lubricant composition may further comprise an initiator. One or more initiators may be present. Suitable initiators which can be present include photo-initiator systems and redox-initiator systems.

[0136] The dental article further comprises a dental material.

[0137] The dental material is located in the compartment of the dental article.

[0138] The dental material is in contact with the lubricant composition. That is, the lubricant compositions functions as an interface between the inner surface of the compartment and the dental materials stored therein.

[0139] The lubricant layer is surrounding the dental material in the area where the dental material would otherwise be in direct contact with the inner surface of the compartment of the dental article.

[0140] The dental material is different with respect to its chemical composition from the lubricant composition.

[0141] The dental material stored in the dental article of the present text is a material comprising polymerizable components, in particular ethylenically unsaturated groups.

[0142] The dental material may further comprise filler. The filler of the dental material can be same as or different from the filler which may be present in the lubricant composition.

[0143] The dental material may further comprise an initiator. The initiator can be same as or different from the initiator which may be present in the lubricant composition.

[0144] The dental article can be further characterized by the following features alone or in combination: (a) The inner diameter of the tube-shaped compartment is larger than the diameter of piston body.

[0145] (b) The inner diameter of the tube-shaped compartment is equal to or lower than the diameter of seal B of the piston assembly. (c) The viscosity of the dental material is larger than the viscosity of the lubricant composition.

[0146] (d) The volume of the collection reservoir is at least as large as the volume of the lubricant composition applied to the inner surface of the tube-shaped compartment.

[0147] (e) The axial length of the tube-shaped compartment is larger than the inner diameter of the tube-shaped compartment at least by a factor of 5. (f) The inner diameter of the compartment is larger than the width of the gaps of seal A at least by a factor of 50.

[0148] In certain aspects, the dental article described in the present text can be characterized by the following dimensions:

[0149] Embodiment 1 A dental article as described in the present text characterized by the following dimensions:

[0150] Embodiment 2

[0151] A dental article as described in the present text characterized by the following dimensions:

[0152] The dental article described in the present text is not for applying materials intramuscular or intravenous of a human being.

[0153] Similarly, the dental article is not for sampling body fluids (e.g., blood) from a human being.

[0154] The invention is also directed to a process of producing the dental article described in the present text.

[0155] Such a process typically comprises the following steps: providing the application device as described in the present text, applying a layer of lubricant composition as described in the present text to the inner surface of the application device, placing the dental material as described in the present text into the tube-shaped compartment in contact with the lubricant composition, inserting the piston assembly as described in the present text into the proximal end of the tube-shaped compartment.

[0156] The application device itself is typically produced by injection-moulding.

[0157] Alternatively, the application device can also be produced by 3d-printing.

[0158] The lubricant composition can be applied by spraying or coating with an appropriate coating device, e.g., a sponge impregnated with the lubricant composition.

[0159] The application device and its individual parts are typically made out of plastic, preferably materials which can be injection molded.

[0160] The material of the application device is typically selected from PP (polypropylene), PE (polyethylene), PA (polyamide), PBT (polybutadiene terephthalate), PET (polyethylene terephthalate), COC (cycloolefin-copolymer).

[0161] To prevent an undesired curing of the dental material during storage, the material of the application device, and in particular the material of the compartment is typically non-transparent to visible light (380 to 750 nm).

[0162] If desired and for further protecting the dental material from light during storage, the dental article can comprise a removable cap at the dispensing section.

[0163] The invention is also directed to a process of dispensing the dental material from the dental article described in the present text.

[0164] The process for dispensing comprises the steps of optionally removing a cap from the dispensing section, applying an extrusion force to the dental material located at the proximal end of the compartment of the dental article, the extrusion force being in a range of 5 to 150 N, or in a range of 5 to 60N.

[0165] The force to be applied is in a range which can be provided by a practitioner without big efforts and without the need for using additional gadgets or specific packaging devices such as screw syringes. By moving the piston assembly in distal direction, the dental material stored in the tube-shaped compartment is dispensed.

[0166] The invention is also directed to a kit of parts comprising the dental article described in the present text and the following items in addition alone or in combination:

[0167] Dental adhesives are typically acidic dental composition with a rather low viscosity (e.g., 0.01 to 3 Pa*s at 25°C). Dental adhesives directly interact with the enamel or dentin surface of a tooth. Dental adhesives are typically one-part compositions, are radiation-curable and comprise ethylenically unsaturated component! s) with acidic moiety, ethylenically unsaturated component! s) without acidic moiety, water, sensitizing agent(s), reducing agent(s) and additive(s).

[0168] Examples of dental adhesives are described in US 2020 / 0069532 Al (Thalacker et al.) and US 2017 / 0065495 Al (Eckert et al.). Dental adhesives are also commercially available, e.g., 3M™ Scotchbond™ Universal (3M Oral Care).

[0169] Suitable dental primers are described in US 6,126,922 (Rozzi et al.) and WO 00 / 69393 Al (3M). Dental primers are also commercially available, e.g. 3M™ Transbond™ XT Primer (3M Oral Care).

[0170] Dental cements which can be added to the kit include in particular self-adhesive resin cements, which contain an acidic polymerizable component (e.g. a (meth)acrylate component bearing a phosphoric or carboxylic acid moiety), polymerizable components without an acidic moiety, an initiator system and filler.

[0171] Suitable dental cements are also commercially available, such as RelyX™ Unicem 2, RelyX™ Universal or RelyX™ Luting Plus (3M Oral Care).

[0172] Suitable dental curing lights are described in US 10,758,126 B2 (Geldmacher et al.) or US 10,231,810 B2 (Gramann et al). Dental curing lights are also commercially available, e.g. 3M™ Elipar™ S10 or 3M™ Elipar™ DeepCure S LED curing light (3M Oral Care).

[0173] The instruction for use describes how the dental product should be used in daily practice, e.g. outlining the application steps and optional curing conditions.

[0174] The following description of the figures is given to illustrate the invention.

[0175] Reference signs and possible and preferred ranges or dimensions of the dental article are described in the table below.

[0176] Fig. 1 shows a perspective view of an embodiment of the dental article (10). At the distal end of the application device (20) there is a dispensing section (50). Shown is also a piston rod (80) for transferring pressure on the piston assembly located within the compartment of the application device (not shown).

[0177] Fig. 2 shows a cross-section of a portion of the dental article (10) with the compartment (30), the inner surface of the compartment (31), the inner diameter of the compartment Dc(34), the outer diameter of the compartment (35), the wall thickness of the compartment (36).

[0178] Within the compartment (30) the piston assembly (40) is arranged. The piston assembly comprises a piston body (41) with a diameter DPB(46). At the front end of the piston body there is located seal A (42). Seal A (42) is a so-called gap seal having gaps (43) with a width WSA (48). The piston assembly further comprises a collection reservoir (45). In this embodiment, the collection reservoir (45) comprises two areas. One area is located within a hollow portion of the piston body (41). The other area is formed by the volume between seal A (42) and seal B (44). Both areas are in connection with each other through openings (47).

[0179] In Fig. 3 A to 3D different embodiments of the piston assembly (40) are shown.

[0180] The piston assembly (40) of Fig. 3A has a plate-shaped seal A (42) at the distal end. The gap is a circumferential slit surrounding seal A (42). Shown is also seal B (44) which is a tight seal. Shown are also two openings (47) to a hollow portion of the piston body which is a part of the collection reservoir.

[0181] Gap (43) of seal A (42) of the piston assembly shown in Fig. 3B is an intermitted gap seal.

[0182] The piston assembly (40) shown in Fig. 3C is similar to the piston assembly (40) of Fig. 3B. However, the piston assembly (40) comprises in addition a pin (49) at the distal. Further, seal A (42) has fewer, but broader gaps (43) which are also circumferentially arranged.

[0183] In Fig. 3D a further embodiment of a piston assembly is shown. At the distal end there is seal A (42) with circumferential arranged gaps (43). At the proximal end there is seal B (44) being a tight seal. Shown is also a small ventilation opening (48) at the proximal end of the piston assembly. Between seal A (42) and seal B (44) there is located collection reservoir (45) which in this embodiment comprises 4 sections, two of which are shown.

[0184] In Fig 4A to Fig. 4B the working principle of the dental article is illustrated.

[0185] The dental article in its initial state is shown in Fig. 4A. On the inner surface of the compartment there is located a lubrication composition (60) with a certain layer thickness TLC (61). The lubrication composition (60) is in contact with dental material (70). The compartment has a proximal end (32) and a distal end (33). An area of the collection reservoir (45) is located in a hollow portion of the piston assembly (40) which is accessible through two openings (47).

[0186] In Fig. 4B the piston assembly has been slightly moved in distal direction so that the dental material (70) is starting to be dispensed from the dispensing section (50) of the application device. A small portion of the lubrication composition (60) has already passed gap (43) in seal A and has entered collection reservoir (45).

[0187] In Fig. 4C the piston assembly has been further moved in distal direction and most of the dental material (70) has been dispensed from the dispensing section (50). Due to tight seal B (44) of the piston assembly, the lubrication composition (60) cannot flow into the space between the proximal portion of the piston body and the inner surface (31) of the compartment but is forced to flow into the collection reservoir (45) through the two openings (47). The lubrication composition (60) is now mainly located in the collection reservoir (45).

[0188] In Fig. 4D seal A (42) of the piston assembly has reached the distal end of the compartment and essentially the entire dental material (70) has been dispensed from the dental article. Further, essentially the entire lubrication composition (60) is now located in the collection reservoir (45).

[0189] If desired, the viscosity of the lubricant composition and / or dental material can be measured with a Physica MCR 301 (Anton Paar Germany GmbH, Ostfildem-Schamhausen). Flowable composites and monomers can be measured at 25.0°C with a shear rate of 10 / s with a 15 mm plate / plate system and a gap of 0.2 mm.

[0190] If desired, extrusion force can be measured with a universal testing machine from ZwickRoell: Zwick 010, Load cell Xforce K, Nominal Force lOkN, testing speed 0.25 mm / s.

[0191] The sample to be tested (packaging device with lubricant composition and dental material) is placed vertically in a sample holder in a universal testing machine, the front outlet is pointing downwards. On top of the syringe’s plunger, the bolt with its attached load cell of the testing machine is applied to press out the dental material from the application device at ambient conditions (23°C). During this process the applied force is recorded.

[0192] The complete disclosures of the patents, patent documents, and publications cited herein are incorporated by reference in their entirety as if each were individually incorporated. Various modifications and alterations to this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention. The above specification, examples and data provide a description of the manufacture and use of the compositions and methods of the invention. The invention is not limited to the embodiments disclosed herein. One skilled in the art will appreciate that many alternative embodiments of the invention can be made without departing from the spirit and scope of thereof.

Claims

Claims1. A dental article (10) comprising an application device (20) with a compartment (30) having an inner surface (31), a piston assembly (40) moveably located in the compartment (30), the piston assembly comprising a piston body (41), a seal A (42) at the front end of the piston body, seal A having one or more gaps (43), a seal B (44) spaced apart from seal A, a collection reservoir (45) suitable for collecting a lubricant composition during the dispensing of a dental material, a dispensing section (50) located at the distal end of the compartment, a lubricant composition (60) located on the inner surface of the compartment, and a dental material (70) being located in the compartment in contact with the lubricant composition.

2. The dental article (10), in particular according to claim 1, the dental article comprising an application device (20) with a tube-shaped compartment (30), the compartment having an inner surface (31), a proximal end (32), a distal end (33), an inner diameter Dc(34), and an axial length Lc(37), a piston assembly (40) moveably located in the tube-shaped compartment, the piston assembly comprising a cylindrical piston body (41) with a diameter DPB (46), optionally a piston rod (80) connected to or attachable to the piston body, a seal A (42) at the front end of the piston body (41), seal A (42) having one or more gaps (43) with a width WSA (43a) in the direction of the inner surface (31) of the compartment, the gaps (43) being preferably circularly arranged, a seal B (44) spaced apart from seal A (42), seal B being a tight seal in contact with the inner surface (31) of the compartment, and a ventilation opening, located preferably in the direction of the distal end (33) of the compartment, the ventilation opening having a diameter DVo, a collection reservoir (45) suitable for collecting a lubricant composition during the dispensing of a dental material, the collection reservoir being accessible through the one or more gaps (43) in seal A (42), and having a volume VCR,a dispensing section (80) located at the distal end (33) of the tube-shaped compartment (30), a lubricant composition (60) with a volume VLC, the lubricant composition being located on the inner surface (31) of the tube-shaped compartment (30), and a dental material (70) comprising polymerizable components, the dental material being located in the compartment (30) in contact with lubricant composition (60), the dental article meeting the equation De > DPB3. The dental article according to any of the preceding claims, at least one portion of the collection reservoir (45) being located in a hollow area of the piston body (41).

4. The dental article according to any of the preceding claims comprising a piston rod (80) connected to the piston body (41), the piston rod (80) having a hollow area which is in communication with the collection reservoir (45).

5. The dental article according to any of the preceding claims, at least one portion of the collection reservoir (45) being located in the area between seal A (42) and seal B (44).

6. The dental article according to any of the preceding claims, the one or more gaps (43) having a shape selected from a circumferential slit, a gear rim, or an intermitted gap seal.

7. The dental article according to any of claims 2 to 7, the dispensing section (50) being tapered and / or comprising a dispensing nozzle.

8. The dental article according to any of the preceding claims, the piston assembly (40) comprising a pin (49) at the distal end.

9. The dental article according to any of the preceding claims, the lubricating composition (60) comprising polymerizable components.

10. The dental article according to any of the preceding claims, the dental material (70) comprising an initiator system for curing polymerizable components.

11. The dental article according to any of the preceding claims, the dental material (70) being a dental restorative material.

12. The dental article according to any of claims 2 to 11 characterized by the following equations alone or in combination: a) Lc / Dc> 5, b) DC / WSA> 50.

13. A process of producing the dental article described in any of the preceding claims, the process comprising the steps of providing the application device (20) described in any of the proceeding claims, applying a layer of lubricant composition (60) described in any of the proceeding claims to the inner surface (31) of the application device (20), placing the dental material (70) described in any of the proceeding claims into the compartment (30) in contact with the lubricant composition (60), inserting the piston assembly (40) described in any of the proceeding claims into the compartment (30).

14. A process of dispensing the dental material (70) from the dental article (10) described in any of the preceding claims, the process comprising the steps of applying an extrusion force to the dental material (70) located at the proximal end of the compartment (30) of the dental article, the extrusion force being in a range of 5 to 150 N.

15. A kit of parts comprising the dental article (10) described in any of the preceding claims comprising the following items in addition alone or in combination:_dental curing light, dental etchant, dental primer, dental adhesive, dental cement.

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