Patent Application
20240139076
The present invention relates to the field of dentistry. Especially, the invention relates to the provision of a calcium silicate-based dental composition useful to prepare a hardened dental material with improved properties, especially an improved compressive strength and a better resistance to solubilization in aqueous environment.
Dental restoration aims at restoring of the integrity and morphology of teeth, including restoring the loss of mineralized substance due to carries or resulting from an external trauma. Direct restoration is performed by placing a malleable filling material into a prepared tooth, followed by the in situ setting of the material.
Ideally, the dental material should possess several properties, including adequate adhesive ability, insolubility, dimensional stability, biocompatibility, bioactivity and suitable mechanical properties. Various types of filling material are available, among which calcium silicate-based cements.
The implementation of the dental material often requires a first phase of preparation by the practitioner of the filling material, followed by a period of in situ hardening. This is especially the case when using a hydraulic dental cement, such as a calcium silicate-based cement, which has to be exposed to water, usually by mixing an anhydrous powder cement phase with a liquid aqueous phase, in order to initiate hardening.
The main parameters to be controlled when providing a dental calcium silicate-based cement comprise the handling properties, the setting time and the mechanical properties of the hardened material as well as its solubility overtime.
Regarding the handling properties, the texture of the filling material has to be creamy for a good handling by the practitioner. Further, the working time should be just sufficient to enable the preparation of the filling material and its placement where restoration is needed.
The setting time should ideally be relatively short. Indeed, a too long setting time would be uncomfortable for the patient, may lead to the washout of the restorative material by saliva and to the irritation of oral tissues.
The hardened restoration material should have a limited, if any, solubility in aqueous environment overtime, so as to avoid its degradation and to ensure its durability.
The hardened restoration material should also have mechanical properties similar to those of the teeth. Especially, the compressive strength has to be sufficient to avoid breakage of the restorative material and ensure its longevity.
European patents EP 2 555 740 and EP 1 531 779 disclose compositions suitable for restoring mineralized substance, especially in the dental field. Said compositions are obtained from the mixing of an aqueous liquid solution with a powder comprising calcium silicate, calcium carbonate, calcium oxide, and optionally zirconium oxide and/or at least one pigment. Selection of suitable ranges for each component and of suitable weight ratios between the aqueous liquid solution and the powder affords a hardened dental material presenting suitable mechanical properties. For instance, the compressive strength of the obtained hardened dental material is of around 100 to 200 MPa.
However, there still exists a demand of patients and practitioners for dental materials having higher mechanical properties and a limited solubility, in order to improve their resistance to breakage and their longevity.
The inventors surprisingly evidenced that including at least one pozzolanic material in a known composition suitable as dental composition afforded a consequent increase, of the order of 14 to 30%, of the compressive strength of the obtained hardened dental material. Other tested compositions even leaded to 3 fold increase of compressive strength, as evidenced in the examples hereafter. Moreover, the presence of a pozzolanic material enables to limit the solubility in aqueous environment of the obtained hardened dental material.
The use of pozzolanic materials is known with Portland cements in order to improve the properties thereof.
Nevertheless, to the inventors' knowledge, the use of pozzolanic materials for improving the mechanical properties, especially the compressive strength, and the insolubility of a hardened dental material based on calcium silicate was never disclosed.
The present invention relates to a dental composition comprising:
In one embodiment, the at least one pozzolanic material comprises, preferably consists of, silica fume.
In one embodiment, the particles of the at least one pozzolanic material have a d90 granulometry from 5 μm to 100 μm, from 8 μm to 60 μm, from 15 μm to 35 μm or from 15 μm to 25 μm, preferably from 8 μm to 35 μm.
In one embodiment, the calcium silicate is pure tricalcium silicate. In another embodiment, the calcium silicate is a mixture of tricalcium silicate and dicalcium silicate, said mixture being such that it contains no more than 10% by weight of dicalcium silicate with respect to the total weight of the calcium silicates present in the composition. In one embodiment, the calcium silicate is the calcium silicate of a Portland cement or of a mineral trioxide aggregate (MTA).
In one embodiment, the dental composition according to the invention further comprises a setting accelerator, preferably calcium oxide or calcium chloride. In one embodiment, the dental composition according to the invention further comprises a radiopacifier, preferably zirconium oxide or bismuth oxide. In one embodiment, the dental composition according to the invention further comprises at least one pigment, preferably at least one iron oxide. In one embodiment, the dental composition according to the invention further comprises at least one texturing agent.
The invention also provides a kit for producing a hardened dental material, said kit comprising:
The invention further provides a medical device comprising the kit according to the invention.
The invention also relates to a dental composition according to the invention, or a kit according to the invention, for use in the treatment of the crown of a tooth and/or the root of a tooth.
In the present invention, the following terms have the following meanings:
Further, in the present invention, when referring to a range, the following is meant: “ranging from X to Y” means that X and Y are included in the range; “ranging from more than X, up to Y” means that X is not included in the range while Y is included in the range; and “less than X” means that the range includes X or lower values.
In the present invention, the term “comprise” and any variation thereof should be understood as open terms and as not excluding the presence of any further components (when it relates to a product) or of any further step (when it relates to a process). In specific embodiments, the term “comprise” and its variation may be understood as “consist essentially of”, or even “consist of”.
The invention relates to the provision of a calcium silicate-based dental composition useful to prepare a hardened dental material with improved properties. The dental composition or the hardened dental material of the invention is intended to be in prolonged contact (more than 30 days) with dental tissues. The dental composition or the hardened dental material of the invention is particularly suitable for restoring decay lesions in dental crowns.
The invention thus relates to a dental composition comprising calcium silicate, calcium carbonate and at least one pozzolanic material.
Preferably, the dental composition of the invention comprises a mixture of powders of:
In an embodiment, the dental composition according to the invention comprises:
In an embodiment, the dental composition according to the invention comprises:
In a first embodiment, the dental composition according to the invention comprises:
In a second embodiment, the dental composition according to the invention comprises:— from 15% to 50%, or from 15% to 25% in weight of the total weight of the composition, of calcium silicate;
In a preferred embodiment, the dental composition is in powder form. In a preferred embodiment, the dental composition is anhydrous or water-free. Indeed, in presence of water, calcium silicate begins hardening.
The dental composition according to the invention is suitable for preparing a hardened dental material. Preferably, in order to prepare a hardened dental material, the dental composition according to the invention is mixed with an aqueous phase, preferably a liquid aqueous phase.
According to one embodiment, the calcium silicate is selected from tricalcium silicate, dicalcium silicate or any mixtures thereof; preferably is tricalcium silicate.
According to one embodiment, tricalcium silicate is selected from compounds of formula Ca3SiO5 (also noted as “C3S”) and of formula Ca3Si3O9 (also called “calcium oxosilanediolate”), preferably C3S.
According to one embodiment, dicalcium silicate is the compound of formula Ca2SiO4 (also noted as “C2S”).
According to one embodiment, the calcium silicate is pure tricalcium silicate.
According to one embodiment, the calcium silicate is a mixture comprising or consisting essentially of tricalcium silicate and dicalcium silicate. Advantageously, this mixture is such that it comprises no more than 10% by weight of dicalcium silicate with respect to the total weight of the calcium silicates present in the composition, typically dicalcium silicate and tricalcium silicate. According to a preferred embodiment, the mixture comprises or consists of 0% to 10% dicalcium silicate and 90% to 100% tricalcium silicate, by weight with respect to the total weight of the calcium silicates. The term “consists of” means in particular that the mixture does not contain any calcium silicate other than dicalcium silicate and tricalcium silicate.
In an embodiment, the calcium silicate is in the form of calcium silicate particles.
In an embodiment, at least part of the calcium silicate, preferably all calcium silicate, is in the form of ultrafine calcium silicate particles. In said embodiment, the ultrafine particles of calcium silicate preferably have:
In an embodiment, at least part of the calcium silicate, preferably all calcium silicate, is in the form of crushed calcium silicate particles. In said embodiment, the crushed calcium silicate particles preferably have:
In an embodiment, at least part of the calcium silicate, preferably all calcium silicate, is in the form of coarsely grinded calcium silicate particles. In said embodiment, the coarsely grinded calcium silicate particles preferably have:
In an embodiment, at least part of the calcium silicate, preferably all calcium silicate, is in the form of micronized calcium silicate particles. In said embodiment, the micronized particles of calcium silicate preferably have:
In one embodiment, the calcium silicate may be the calcium silicate present in a Portland cement. In another embodiment, the calcium silicate may be the calcium silicate present in mineral trioxide aggregate (MTA).
The dental composition comprises calcium carbonate CaCO3, which is in the form of a white or roughly white powder practically insoluble in water.
According to one embodiment, the amount of calcium carbonate, preferably of calcium carbonate particles, in the dental composition of the invention ranges from more than 0% wt. to 80% wt., preferably from 0.5% wt. to 20% wt., preferably from 1% wt. to 15% wt., more preferably from 1% wt. to 7% wt. by the total weight of said composition. According to one embodiment, the amount of the calcium carbonate is of 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20% wt., by the total weight of said composition.
The dental composition comprises at least one pozzolanic material.
In an embodiment, the at least one pozzolanic material is selected from the group consisting of fly ash, silica fume, metakaolin, slag and rice husk ash. Preferably, the at least one pozzolanic material is silica fume.
According to an embodiment, the at least one pozzolanic material comprises, preferably consists of, silica fume.
In one embodiment, silica fume is white silica fume, black silica fume or a mixture thereof. In one embodiment, silica fume is white silica fume. In one embodiment, silica fume is black silica fume.
According to one embodiment, the amount of pozzolanic material in the dental composition of the invention ranges from more than 0% wt. to 20% wt., preferably from 0.5% wt. to 20% wt., preferably from 1% wt. to 15% wt., more preferably from 5% wt. to 15% wt. by the total weight of said composition. In one specific embodiment, the amount of pozzolanic material in the dental composition of the invention ranges from 10% wt. to 15% wt. by the total weight of said composition. According to one embodiment, the amount of the pozzolanic material in the composite material of the invention is 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20% wt., by the total weight of said composition. According to one embodiment, the amount of the pozzolanic material in the composite material of the invention is 10, 11, 12, 13, 14, or 15% wt., by the total weight of said composition. According to one embodiment, the amount of the pozzolanic material in the composite material of the invention is 10% or 15% wt., by the total weight of said composition.
In an embodiment, the pozzolanic material and the calcium carbonate are present as a mixture of pozzolanic material and calcium carbonate. In a preferred embodiment, the mixture of pozzolanic material and calcium carbonate represents from more than 0% wt. to 30% wt., preferably from 1% wt to 20% wt, more preferably from 1% wt. to 15% wt. by the total weight of said composition.
According to one embodiment, the pozzolanic material particles are subjected to sieving prior to their mixing with the other ingredients of the dental composition. According to one embodiment, the pozzolanic material particles are subjected to sieving with at least one sieve. In one specific embodiment, the pozzolanic material particles are subjected to sieving with two sieves presenting two different sieve openings. In one embodiment, the pozzolanic material particles are sieved with at least one sieve presenting sieve openings of less than 105 μm, preferably less than 90 μm, even more preferably less than 75 μm. In one embodiment, the pozzolanic material particles are sieved with at least one sieve presenting a sieve opening of 53 μm, and/or at least one sieve presenting a sieve opening of 11 μm. In one embodiment, the pozzolanic material particles are sieved with at one sieve presenting a sieve opening of 53 μm.
According to one embodiment, the pozzolanic material particles have a d10 granulometry ranging from 0.1 μm to 8.5 μm, from 0.3 μm to 8 μm, from 0.3 μm to 5 μm, or from 0.45 μm to 8 μm. According to one embodiment, the pozzolanic material particles have a d10 granulometry ranging from 5 μm to 8.5 μm. According to one embodiment, the pozzolanic material particles have a d10 granulometry ranging from 3 μm to 5 μm. According to one embodiment, the pozzolanic material particles have a d10 granulometry ranging from 2 μm to 3 μm. According to one embodiment, the pozzolanic material particles have a d10 granulometry ranging from 0.1 μm to 1 μm. According to one embodiment, the pozzolanic material particles have a d10 granulometry ranging from 0.3 μm to 2.5 μm.
According to one embodiment, the pozzolanic material particles have a d50 granulometry ranging from 1 μm to 30 μm, from 1.5 μm to 30 μm, from 1.5 μm to 16 μm, or from 1.5 inn to 8 μm.
According to one embodiment, the pozzolanic material particles have a d90 granulometry ranging from 5 μm to 100 μm, from 8 μm to 60 μm, from 15 μm to 35 μm or from 15 μm to 25 μm, preferably from 8 μm to 35 μm.
According to one embodiment, the pozzolanic material particles of the dental composition, typically selected from white and/or black fume silica, as defined above present:
In one embodiment, the at least one pozzolanic material comprises silica fume, preferably white silica fume, and colloidal silicon dioxide (preferably Aerosil 200). In one embodiment, the dental composition comprises from 0.05 to 1.5% wt. of colloidal silicon dioxide by the total weight of the dental composition. Advantageously, the presence of colloidal silicon dioxide enables to break aggregates that may be present in silica fume, in particular in white silica fume.
According to one embodiment, the dental composition according to the invention further comprises at least one additive, preferably selected from the group consisting of radiopacifiers, setting accelerators, pigments, water reducing agents, texturing agents, pH stabilizing agents, surfactants, fillers, and any mixtures thereof.
According to one embodiment, the at least one additive is comprised in the dental composition in an amount ranging from 0% to 60% in weight to the total weight of the composition; preferably from 2% to 50%; more preferably from 2% to 35%.
According to one embodiment, the dental composition comprises at least one radiopacifier. The radiopacifier is preferably selected from the group consisting of zirconium oxide, bismuth oxide, cerium oxide, barium sulphate, calcium tungstate, titanate dioxide, ytterbium oxide and mixtures thereof. In a specific embodiment, the radiopacifier is zirconium oxide or bismuth oxide, in particular zirconium oxide.
According to one embodiment, the dental composition comprises from 0% to 40% of radiopacifier in weight to the total weight of said composition; preferably from 2% to 35%, from 5% to 35%, preferably 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34 or 35%.
According to one embodiment, the dental composition comprises at least one setting accelerator. The setting accelerator is preferably selected from the group consisting of calcium carbonate, calcium oxide, calcium phosphate, sodium bicarbonate, calcium lactate, calcium chloride and any mixtures thereof, preferably calcium carbonate, calcium oxide or mixtures thereof. According to one embodiment, the setting accelerator is calcium oxide or calcium chloride.
According to one embodiment, the dental composition comprises from 0% to 25% of setting accelerator in weight to the total weight of said composition; preferably from 4% to 20%, preferably from 4 to 15%, preferably 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20%.
According to one embodiment, the dental composition comprises at least one pigment. The pigment is preferably selected from iron oxides. One skilled in the art is able to select suitable mixtures of pigments so that the composition has the expected color. For instance, the iron oxide may be selected from the group consisting of yellow, red and brown iron oxides.
According to one embodiment, the dental composition comprises from 0% to 1.5% of pigment in weight to the total weight of said composition; preferably from 0.5% to 1%.
According to one embodiment, the dental composition comprises at least one water-reducing agent. The water-reducing agent is preferably selected from the group consisting of glenium, polynaphthalene sulfonate and modified polycarboxylate.
According to one embodiment, the dental composition comprises at least one texturing agent. The texturing agent is preferably selected from the group consisting of silica, povidone (also named polyvinylpyrrolidone), cellulose or derivatives thereof such as methylcellulose, hydroxypropylcellulose and hydroxyethylcellulose, polymers such as acrylamide/sodium acryloyldimethyltaurate copolymer isohexadecane and hydroxyethyl acrylate/sodium acryloyl dimethyl taurate copolymer, fumed silica (hydrophilic and/or hydrophobic), xanthan gum, and any mixtures thereof.
According to one embodiment, the dental composition comprises at least one pH stabilizing agent. According to one embodiment, the pH stabilizing agent is a mineral acid or an organic acid.
According to one embodiment, the dental composition comprises at least one surfactant. According to one embodiment, the surfactant is a polysorbate.
According to one embodiment, the dental composition comprises at least one filler. According to one embodiment, the filler is a mineral filler.
The dental composition may further comprise any other component or additive known in the art and suitable for improving any of its properties, such as its mechanical properties, its setting time, its texture and/or its appearance. The nature and amount of the additives to be added to the dental composition may be easily determined by one of ordinary skill in the art on the basis of the desired properties of the dental composition and/or of the hardened dental material to be obtained.
According to one embodiment, the dental composition according to the invention does not comprise any aluminate, such as calcium aluminate. According to one embodiment, the dental composition according to the invention does not comprise any halogen or halogenated compounds, such as for example fluoride. According to one embodiment, the dental composition according to the invention does not comprise any phosphates such as for example calcium phosphate. According to one embodiment, the dental composition according to the invention does not comprise any porous compounds. According to one embodiment, the dental composition according to the invention does not comprise any porous fillers and/or porous fibers.
The invention also relates to a hardened dental material comprising calcium silicate, at least one pozzolanic material, and a compound of general formula mCaO·nSiO2·pH2O in which m and n each independently vary from 1 to 3 and p varies from 3 to 6.
The hardened dental material of the invention preferably results from the hydration of a hydraulic cement comprising calcium silicate; preferably selected from tricalcium silicate, dicalcium silicate, Portland cement, mineral trioxide aggregate (MTA) and any combinations thereof; more preferably the composite material of the invention results from the hydration a hydraulic cement comprising tricalcium silicate. According to one embodiment, the hardened dental material of the invention results from the hydration of a hydraulic cement comprising calcium silicate particles.
According to an embodiment, the hardened dental material according to the invention comprises:
According to an embodiment, the hardened dental material further comprises calcium carbonate.
According to an embodiment, the hardened dental material comprises:
According to an embodiment, the hardened dental material according to the invention comprises:
According to one embodiment, the hardened dental material of the invention results from the hydration of dental composition according to the present invention.
Above embodiments, and especially those relative to calcium silicate, calcium carbonate and pozzolanic material, apply mutatis mutandis to the hardened dental material of the invention.
According to one embodiment, the amount of calcium carbonate, preferably of calcium carbonate particles, in the hardened dental material of the invention ranges from more than 0% wt. to 20% wt., preferably from 1% wt. to 15% wt., more preferably from 1% wt. to 7% wt. by the total weight of said hardened dental material. According to one embodiment, the amount of the calcium carbonate is of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20% wt., by the total weight of said hardened dental material.
In an embodiment, at least part of the calcium carbonate of the hardened dental material is in the form of calcium carbonate particles. According to one embodiment, the calcium carbonate particles have a d10 granulometry ranging from 1 nm to 500 nm, preferably a d10 granulometry of 440 nm. According to one embodiment, the calcium carbonate particles have a d50 granulometry ranging from 1 nm to 1500 nm, preferably a d50 granulometry of 1100 nm. According to one embodiment, the calcium carbonate particles have a d90 granulometry ranging from 1 nm to 5 000 nm, preferably a d90 granulometry of 3550 nm. According to the invention, the granulometry may be measured by a Beckman-Coulter LS230 granulometer appliance with SVM module.
According to one embodiment, the amount of pozzolanic material in the hardened dental material of the invention ranges from more than 0% wt. to 20% wt., preferably from 1% wt. to 15% wt., more preferably from 1% wt. to 7% wt. by the total weight of said hardened dental material. According to one embodiment, the amount of the pozzolanic material in the composite material of the invention is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20% wt., by the total weight of said hardened dental material.
In an embodiment, the pozzolanic material and the calcium carbonate are present as a mixture of pozzolanic material and calcium carbonate. In a preferred embodiment, the mixture of pozzolanic material and calcium carbonate represents from more than 0% wt. to 30% wt., preferably from 1% wt to 20% wt, more preferably from 1% wt. to 15% wt. by the total weight of said hardened dental material.
In an embodiment, the mixture of pozzolanic material and calcium carbonate comprises from 0.5% to 20% of pozzolanic material and from 0.5% to 20% of calcium carbonate, in weight with respect to the total weight of the hardened dental material.
According to an embodiment, the hardened dental material further comprises a setting accelerator, preferably calcium oxide or calcium chloride.
According to an embodiment, the hardened dental material further comprises a radiopacifier, preferably zirconium oxide or bismuth oxide.
According to an embodiment, the hardened dental material further comprises at least one pigment, preferably at least one iron oxide.
According to an embodiment, the hardened dental material further comprises at least one texturing agent.
Compound of General Formula mCaO·nSiO2·pH2O
The hardened dental material comprises a compound of general formula mCaO·nSiO2·pH2O. The compound of general formula mCaO·nSiO2·pH2O, is generally referred to as CSH for Calcium Silicate Hydrates. CSH may be obtained by reacting calcium silicate with water.
n, m and p are integers. n and m, each independently, vary from 1 to 3, and p varies from 3 to 6. In an embodiment, n is 1, 2 or 3. In an embodiment, m is 1, 2 or 3. In an embodiment, p is 3, 4, 5 or 6. In an embodiment, m is 3, n is 2 and p is 3.
In the case of tricalcium silicate, CSH is a hydrate that forms by heterogeneous germination on the surface of the tricalcium silicate crystals and develops by aggregation of nanocrystals in order to cover the entire surface of the calcium silicate crystals.
The hardened dental material according to the invention unexpectedly presents interesting mechanical properties. Actually, replacing at least part of the calcium carbonate of a known hardened dental material with at least one pozzolanic material unexpectedly afforded a 14 to 30% increase of the compressive strength of said material. Other tested compositions even leaded to 3 folds increase of compressive strength, as evidenced in the examples hereafter.
The compressive strength is advantageously measured 24 h or 72 h after mixing a powder phase (or a hydraulic cement) and an aqueous phase to form the hardened dental material.
Typically, the compressive strength of this hardened dental material 24 h after mixing the powder phase and the liquid aqueous phase has been determined to range from 250 MPa to 330 MPa. Typically, the compressive strength of this hardened dental material 72 h after mixing the powder phase and the liquid aqueous phase has been determined to range from 270 MPa to 370 MPa.
The compressive strength may be measured with reference to ISO 9917-1: 2007. The test tubes are prepared after mixing, using cylindrical Teflon moulds 4 mm in diameter and 6 mm high. In filling the moulds care is taken to eliminate the air bubbles from the paste, stored in an incubator for 15 minutes at 37° C. and 100% relative humidity for the required setting time. The test tubes are then removed from the mould and stored under distilled water at 37° C. for the wanted setting time. The samples are thus preserved under conditions close to their future conditions of clinical use. The compressive strength of the test tubes is measured on five occasions, i.e. 1 hour, 24 hours, 72 hours, 7 days and 28 days, by means of a Universal press (model 2/M, MTS Systems, 1400 Eden Prairie, Minneapolis, USA) with a speed of movement of 0.5 mm per minute.
The hardened dental material according to the invention also presents improved resistance to solubilization in aqueous environment, which reflects an improved durability of the material.
Further, the dental composition according to the invention presents a lesser washout during hardening, compared to a corresponding composition free of pozzolanic material, which is advantageous in particular during endodontic procedures wherein dental cement under hardening should be able to stay into the hole after placement despite the blood flow or the saliva.
The invention further relates to a method of manufacturing the hardened dental material according to the invention. Said method is characterized in that it comprises a mixing step of a liquid aqueous phase and a solid phase consisting of a mixture of powders, preferably the solid phase comprises or consists of a dental composition according to the invention.
The solid phase preferably comprises a mixture of powders of:
In an embodiment, the solid phase is a dental composition according to the invention.
According to one embodiment, the liquid aqueous phase comprises water, preferably purified water.
According to one embodiment, the liquid aqueous phase consists in water. In another embodiment, the liquid aqueous phase is an aqueous solution.
According to one embodiment, the liquid aqueous phase comprises from 10% to 100% of water, in weight to the total weight of said liquid aqueous phase, preferably from 20% to 90%, preferably from 30% to 90%, preferably from 35% to 85%. According to one embodiment, the liquid phase comprises from 50% to 90% of water in weight to the total weight of said liquid phase, preferably from 60% to 90%, more preferably from 60% to 85%, more preferably from 65% to 85%.
According to one embodiment, the liquid aqueous phase comprises at least one additive, wherein the additive is preferably selected from setting accelerators and water reducing agents. According to one embodiment, the liquid aqueous phase comprises one or more additives selected from setting accelerators (such as calcium chloride), water reducing agents (such as modified polycarboxylate, glenium, polynaphthalene sulfonate or mixtures thereof) and mixtures thereof. The liquid aqueous phase preferably comprises calcium chloride, a polycarboxylate and water.
According to one embodiment, the liquid aqueous phase comprises at least one additive in an amount ranging from 0% to 40% in weight to the total weight of the liquid aqueous phase; preferably from 10% to 35%; more preferably from 15% to 35%.
The weight ratio of the solid phase to the liquid aqueous phase to be mixed advantageously ranges from 2 to 5, preferably from 2.0 to 4.5 or from 2.5 to 4.0.
According to one embodiment, the weight ratio of the powder phase to the liquid aqueous phase is 2,0; 2,1; 2,2; 2,3; 2,4; 2,5; 2,6; 2,7; 2,8; 2,9; 3.0; 3.1; 3.2; 3,3; 3,4; 3,5; 3,6; 3,7; 3,8; 3,9; 4.0; 4,1; 4,2; 4,3; 4,4 or 4,5.
Incorporating a pozzolanic material, in particular silica fume, in the dental composition of the invention allows using less aqueous phase for manufacturing the hardened material according to the invention. Without wishing to be bound by any theory, the Inventors believe that this advantage may be due to a fluidifying effect of the pozzolanic material after the mixing step is performed.
The mixing step may be performed by any suitable method known in the art. According to one embodiment, the mixing step is implemented by a vibration mixer.
According to one embodiment, the method for manufacturing the hardened dental material comprises at least one mixing step by vibration of the powder phase with the liquid aqueous phase.
According to one embodiment, the mixing step is implemented with a vibration frequency ranging from 1 rpm to 15 000 rpm; preferably ranging from 1 rpm to 10 000 rpm, preferably ranging from 1000 rpm to 6 000 rpm; more preferably ranging from 3 000 rpm to 5 000 rpm. According to one embodiment, the mixing step is implemented with a vibration frequency of about 1, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1 000, 2 000, 3 000, 4 000, 5 000, 6 000, 7 000, 8 000, 9 000 or 10 000 rpm. According to another preferred embodiment, the mixing step is implemented with a vibration frequency ranging from 1 rpm to 15 000 rpm, preferably from 5 000 rpm to 15 000 rpm, more preferably from 10 000 rpm to 15 000 rpm. According to one embodiment, the mixing step is implemented with a vibration frequency of about 10 000 rpm, 11 000 rpm, 12 000 rpm, 13 000 rpm, 14 000 rpm or 15 000 rpm.
According to one embodiment, the mixing step by vibration is implemented during a vibration time ranging from 1 s to 3600 s; preferably from 1 s to 60 s; more preferably during 30 s. According to one embodiment, the mixing step by vibration is implemented during a vibration time of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 s.
In one embodiment, the method of manufacturing the hardened dental material according to the invention is characterized in that it comprises a mixing step of a solid phase consisting of a mixture of powders and of a liquid aqueous phase,
The invention further relates to the use of a hardened dental material according to the invention in the dental field, as a restorative and/or filling material, preferably for treating the crown of a tooth and/or the root of a tooth.
The use of the hardened dental material of the invention may be for treating the crown of a tooth, for example temporary enamel restoration, permanent dentin restoration, deep or large carious lesions restoration, deep cervical or radicular lesions restoration, pulp capping or pulpotomy; and/or the root of a tooth, such as for example root and furcation perforations, internal/external resorptions, apexification or retrograde surgical filling.
The invention thus further relates to a hardened dental material of the invention for use for treating the crown of a tooth, for example enamel restoration, permanent dentin restoration, deep or large carious lesions restoration, deep cervical or radicular lesions restoration, pulp capping or pulpotomy; and/or the root of a tooth, such as for example root and furcation perforations, internal/external resorptions, apexification or retrograde surgical filling.
The invention also relates to a method for treating the crown of a tooth, for example temporary enamel restoration, permanent dentin restoration, deep or large carious lesions restoration, deep cervical or radicular lesions restoration, pulp capping or pulpotomy; and/or the root of a tooth, such as for example root and furcation perforations, internal/external resorptions, apexification or retrograde surgical filling; in a subject in need thereof, comprising the use of a hardened dental material according to the invention.
Another object of the present invention relates to a method for treating the crown of a tooth, for example temporary enamel restoration, permanent dentin restoration, deep or large carious lesions restoration, deep cervical or radicular lesions restoration, pulp capping or pulpotomy; and/or the root of a tooth, such as for example root and furcation perforations, internal/external resorptions, apexification or retrograde surgical filling; in a subject in need thereof, comprising the use of a composite material of the invention as defined above.
According to one embodiment, the composite materials of the invention may be used in treating a bone and/or dental disorder or disease in a subject in need thereof. According to one embodiment, the present invention refers to the use of the composite materials of the invention for treating a bone and/or dental disorder or disease in a subject in need thereof. According to one embodiment, the present invention refers to a method for treating a bone and/or dental disorder or disease in a subject in need thereof by using the composite materials of the invention.
The invention further relates to a kit for producing a hardened dental material, said kit comprising:
In one embodiment, the kit comprises:
The powder phase is a dental composition according to the invention.
The liquid aqueous phase is as detailed above.
The kit of the invention is particularly suitable for manufacturing a hardened dental material according to the invention.
In a preferred embodiment the powder phase is anhydrous or water-free. Indeed, in presence of water, calcium silicate begins hardening. Therefore, it is important that the powder phase remains free of water during storage to avoid its undesirable setting at this stage.
The invention finally relates to a medical device comprising the kit according to the invention.
In one embodiment, the medical device is an injection system, preferably a syringe, comprising a composition obtained by the mixing of the powder phase and the liquid aqueous phase described above. In one embodiment, the medical device is an injection system, preferably a syringe, comprising the kit powder-liquid described above.
In another embodiment, the medical device is an injection system, preferably a syringe, comprising the dental composition of the invention. In a specific embodiment, the syringe is a dual syringe, one compartment comprising the dental composition of the invention and the second compartment comprising a liquid aqueous phase.
The present invention is further illustrated by the following examples, which are provided as illustrative, and not limitative, of the present invention.
The compressive strength of a hardened dental material comprising calcium silicate and a mixture of calcium carbonate and silica fume according to the invention was measured at 24 h and compared to that of the reference material comprising calcium silicate and calcium carbonate, in absence of silica fume.
The tested hardened material is obtained by mixing 162 μL of water with 700 mg of a powder mixture comprising calcium silicate, fume silica and calcium carbonate.
The reference hardened material is obtained by mixing 173 μL of water with 700 mg of a powder mixture comprising calcium silicate and calcium carbonate.
Silica fume was 53 micrometers sieved.
The powder mixtures for both tested and reference hardened materials are detailed in table 1.
The compressive strength was measured for 7 samples of tested hardened material and for 8 samples of reference hardened material. The test consists of the compression by two metal plates of a test piece approximately 5 mm in height and 4 mm in diameter. The maximum stress (N/S) before rupture of the sample is measured. A compression speed of 0.5 mm/s is used.
The measured compressive strengths for the different samples are presented in table 2.
After 24 h, the compressive strength of the hardened material according to the invention is increased of 14%.
The obtained results were further analyzed with a 2-sample Student t test, which confirmed that the compressive strength mean value obtained for the hardened material according to the invention is significantly higher than compressive strength mean value obtained for the reference material.
The compressive strength of a hardened dental material comprising calcium silicate and a mixture of calcium carbonate and silica fume according to the invention was measured at 72 h and compared to that of the reference material comprising calcium silicate and calcium carbonate, in absence of silica fume.
The tested hardened material and reference hardened material are obtained as detailed in example 1 above.
Silica fume was 53 micrometers sieved.
The compressive strength was measured for 6 samples of tested hardened material and for 7 samples of reference hardened material.
The measured compressive strengths for the different samples are presented in table 3 and in
After 72 h, the compressive strength of the hardened material according to the invention is increased of more than 25%.
The obtained results were further analyzed with a 2-sample Student t test, which confirmed that the compressive strength mean value obtained for the hardened material according to the invention is significantly higher than compressive strength mean value obtained for the reference material.
The mechanical properties, in particular the compressive strength, of the hardened material according to the invention are significantly higher that the mechanical properties, in particular the compressive strength, of the reference hardened material not comprising silica fume. Consequently, the addition of a pozzolanic material such as silica fume confers increased mechanical properties to the hardened dental material.
The increase of compressive strength is higher at 72 h than at 24 h, suggesting that the long-term mechanical properties of the hardened material comprising the pozzolanic material will be at least as good as, if not higher, the mechanical properties at 72 h.
Thus, the hardened material according to the invention presents improved mechanical properties when compared to the reference material, and said properties even improve over time.
Based on the results of Example 1, the following further compositions according to the invention were prepared according to table 4.
The tested compositions C06 and C012 were hardened as defined above using a volume of aqueous phase as indicated in table 5. The mechanical properties of the hardened material were measured as per in example 2.
The results are presented in table 5.
Despite the reductions of C3S inclusion, the addition of a pozzolanic material such as silica fume confers increased mechanical properties to the hardened dental material. Adding colloidal silicon dioxide may further facilitate the rheological properties of the fume silica composition, break any possible fume silica aggregations and contribute to the mechanical properties of the hardened dental composition.
In an alternative approach, the effect of the pozzolanic material selected from white and black fume silica was assessed by removing 10% by weight of the reference composition of example 3 and replacing the removed portion of the powder by the pozzolanic material.
More in detail, the following steps were carried out:
Two compositions where prepared in this manner:
Then, a volume of aqueous liquid phase is added into the Ccaps10W/B compositions and mixed for 30 seconds.
Paste specimens were prepared in compression Teflon molds and placed in a tube containing water, in a water bath at 37 degrees until compression assay as defined above.
The hardened compositions obtained from the Ccaps10W/B compositions were assessed at 24 h, 48 h; 1 week and 28 days and the results are presented in table 6.
The results of Example 4 show that the nature of pozzolanic material does not impact the positive effect of the pozzolanic material inclusion on the mechanical properties of the hardened composition. Example 4 further shows that the pozzolanic material inclusion positively evolves throughout the timeframe of the dental composition's hardening.
The compressive strength of another hardened dental material according to the invention was measured at 7 days and compared to that of the reference material comprising calcium silicate and calcium carbonate, in absence of silica fume.
The tested materials were obtained by mixing the solid phases listed in table 7 below, with an aqueous phase comprising water, calcium chloride and a modified polycarboxylate, in the indicated proportions:
Silica fume was 11 micrometers sieved.
The compressive strength was measured for 8 samples of each material.
The measured compressive strengths at 7 days for the different samples are presented in table 8.
After 7 days, the compressive strength of the hardened material according to the invention is increased by more than 3 folds compared with the corresponding material without pozzolanic material.
The objective of the solubility test is to see the impact of the presence of a pozzolanic material on the solubility of a hardened dental material placed in an aqueous environment. Solubility is an important parameter for dental cement because the more soluble a cement is, the more it will degrade and the less durable it will be.
The solubilization in water of the hardened dental material according to the invention of example 5 was measured overtime (24 h and 7 days) and compared to that of the reference material of example 5.
The procedure of the solubility test is as follows:
The measured solubilities for the different samples are presented in table 9.
After 24 h, the solubilization of the hardened material according to the invention was already reduced compared with the corresponding material without pozzolanic material. The effect of silica fume on the limitation of the solubilization was even more significant after 7 days.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21305262.4 | Mar 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/055648 | 3/4/2022 | WO |
