MXPA00003323A - Dental product, shading kit and method - Google Patents

Abstract

The invention provides a kit and method for the preparation of dental products. First, second and third materials are provided in labeled containers. Preferably the first, second and third materials are pastes or powders. The first material has a lightness value (L1) when formed into a least opaque layer. The second material has a lightness value (L2) when formed into a less opaque layer. The third material has a lightness value (L3) when formed into a most opaque layer. The third lightness value is greater than the second lightness value, which is greater than the first lightness value. The lightness value differences between the third lightness value (L3) and the first lightness value (L1) are less than 10 CIE L*a*b units.

Description

DENTAL PRODUCT. STAMPING CASE AND METHOD The present is a continuation in part of US Serial No. 08 / 456,151 filed May 31, 1995, (Case 1724-DIV) incorporated herein by reference in its entirety, which is a division of the patent of the United States of America No. 08 / 257,411 filed June 9, 1994, now United States Patent No. 5,482,732 incorporated herein by reference in its entirety. The invention relates to a color correlation kit and a method for shading dental products. The color correlation method of the dental product of the invention provides dental restorations which match a shading or shading guide. Using a dental color correlation kit the method of the invention provides dental products such as restorations having a substantially constant clarity value, hue and / or color intensity, from opaque to translucent composites. The kits and methods of the invention are useful for making improved dental fill materials, artificial teeth, crowns and bridges, such as temporary and permanent crowns and bridges. The preparation of the prior art of temporary and permanent crowns and bridges is discussed in the dentist's desk reference: materials, instruments and equipment; first edition, American Dental Association, copyright 1981, pages 131-133, incorporated herein by reference in its entirety. Dental restorations of metal-based composite material such as crowns and bridges comprise a metal frame called "pontic", which is covered by several layers of composite material to simulate the appearance of the natural tooth. The composite material is applied in a plurality of layers, the first layer applied on the pontic is called the "opaque composite layer", the purpose of which is to cal the metal framework. The second layer applied on the first layer is called the "composite layer of the body". The composite body layer exhibits translucency to a degree similar to that of the dentin layer of the natural dentition. In addition, a second layer of "opacity or dentin body" composite material is used in combination with the body material. The opacity body material is more opaque than the layer of the body composite and is preferably used below the body composite or at the location of the body material where the restoration is very thin. Preferably, a layer of dentifrice material is placed on the layer of body material. The layer of denticular material has a translucency approximately equal to the translucency of the enamel layer of the natural dentition. The outer surface is either covered with a very thin transparent layer or polished to a high gloss. The color is imparted to the dental restoration of metal-based composite material by coloring the opaque and body composite layers. It is an object in the production of dental restorations to elaborate restoration that resembles as closely as possible to the patient's natural teeth. Recently, all dental restorations of all ceramic or fiber reinforced composite material have been commercially introduced. These restorations replace the metallic pontic with a ceramic or composite base, and because the metal base is removed, they can be made to more closely resemble the normal denture. However, even with a metal-free restoration, there is obviously still a need to match the color of the patient's natural teeth. One way is to color a restoration all ceramic or all composite material is to color the base by any of several techniques (for example, the color can be incorporated into the same base material, or the base can be dyed with a ceramic dye or organic) It can cure the body composite, a denticular layer and a varnish on the ceramic or composite base, as is the case with metal-based restorations. Whether or not the composite restoration has a metallic base, its apparent color is influenced by the color of the body composite layer and by the color of the layer just below the body composite material. The layers of dentifrice composite and varnish contribute little, if any, to the perceived color of the restoration because they are a little translucent or transparent, and are, mostly, only slightly colored. Since the natural tooth has translucent layers, ie enamel and dentin, the restoration must have translucent layers on its surface to match as much as possible the appearance of the natural tooth. However, the translucence of the composite body layer complicates the task of matching the color of natural teeth. The thickness of the body composite varies from a thick layer in the middle to a thin layer at the gingival or incisal ends of the restoration. In this way, it is normal for the thickness of the composite layer of the body to vary from about% to 1 A millimeters. Because of this thickness variation, light penetrates the composite layer of the body at different depths before it is reflected back to the observer, and unless the layer just below is exactly the same color as the composite material of the body. body, the apparent color of the restoration will vary on its surface with the thickness of the composite material of the body. In this way, the visually discerned color of an opaque object is determined by the amount of visible illumination light reflected (from the surface of the object) towards the observer. The perceived color of a composite dental restoration is mainly the result of diffuse reflection from the translucent body composite layer that covers a more underlying opaque layer. The perceived color is in this way a combination of the scattered and reflected color of a translucent layer plus the reflected color from the underlying layer. When the translucent layer varies in thickness, the amount of color contribution from the underlying layer will vary inversely with the thickness of the translucent layer. Therefore, unless the translucent layer and the underlying layer are closely related to the color, the perceived color of the restoration will be depending on the thickness of the body material layer. Accordingly, it is clear that it is desirable to provide dental restorations of composite material in which the composite material of the body makes the color of the layer underneath. So far, however, there have been no commercial dental composite restorative cases in which the body composite, when cured, exactly matches the hue, color intensity and clarity of the composite layer just below. . The resulting prior art restorations do not match the hue, color intensity or value of the corresponding tone guide component. In order to compensate for this, the dental technician often has to modify the color of the opaque and body material or apply dyeing to the composite material to different portions of the restoration to prevent the perceived color from varying to an undesirable degree from a preselected color. of a tone guide. This was not only a time-consuming task, but also the results were very dependent on the expertise of the expert. According to the invention, composite material having a predetermined hue, color intensity and clarity is produced to match the hue, color intensity and clarity of an underlying, more opaque layer. Preferably, an observer can not visually discern any of the differences in hue, intensity of color and clarity in a composite material that includes a layer of translucent composite material that is located over the underlying layer, even when the layer of translucent composite material varies in thickness.

It is an object of the invention to provide a case for the preparation of dental restorations of composite material having a layer of at least one translucent composite material that is on a more opaque composite layer. The case includes at least one labeled container of colored translucent paste and at least one labeled container of composite material for the most opaque layer, and when the translucent paste and the composite material for the most opaque layer are cured, the colors of the material The translucent composite and the more opaque composite layer match in a photometric spectrum manner such that the two colors have less than 5 degrees of difference in the CIÉ hue angle. It is an object of the invention to provide a method for making crowns and bridges having a translucent layer on an opaque layer, using a composite equipment having a translucent paste having a translucent hue when formed in the translucent layer, and an opaque paste that has an opaque hue when formed in the opaque layer, where the translucent hue is within 5 degrees of the psychometric hue angle of CIÉ of the opaque hue. In the dental restoration of the invention, the layers matched in color are both uniform and equal to each other. "The units L * a * b" are used here to refer to the units of CIÉ according to the 1976 standard. "Composite material", as used here and in dental restoration techniques, refers to the materials of resin containing an organic or inorganic filler. The composite material is used to cover the base or pontic in a restoration such as a crown or bridge. An important function of the composite material in the dental restoration is to provide the aesthetic appearance of the natural dentition. "Composite material", as used herein, includes the composite materials used in a dental restoration, as defined above, and also includes the basis of a fiber reinforced dental restoration.

"Uniform color layers" as used herein, means that the layer has a hue, intensity of color and substantially equal clarity throughout and is free of stains or dyeing of the composite material or the like applied to only a part of the surface of the layer to compensate for the failure of the color matching of the two layers. "Color matching", as used herein, means that when making a composite material having the layers of translucent composite material covering the most opaque layer, an observer can not visually discern any non-uniformity in hue, color intensity and substantially equal clarity of the composite material even when the translucent composite layer thickness can vary over the normal thickness scale for the composite layer of the body in a composite dental restoration (eg, from about half a millimeter to about 1 A millimeters) ). When the color is matched, the color, measured in the infinite optical thickness of the translucent composite material, is the same as the opaque composite material.

BRIEF DESCRIPTION OF THE INVENTION The invention provides a kit and method for the preparation of dental composite materials. First, second and third materials are provided in labeled containers. Preferably, the first, second and third materials are liquids, pastes or powders. The first material has a clarity value (L ^ when it is formed in at least the opaque layer.) The second material has a clarity value (L2) when it is formed in a less opaque layer.The third material has a clarity value (L3) when formed in a very opaque layer The third clarity value is greater than the second clarity value, which is greater than the first clarity value The difference in clarity value between the third clarity value ( L3) and the first value of clarity (L,) are less than 10 units of CIÉ L * a * b. Preferably, the first material has a first hue (Hi) when formed in the less opaque layer, the second material has a second hue (H2) when formed in the less opaque layer, and the third material has a third hue (H3) ) when it forms in the most opaque layer. Preferably the first hue (H-Í) and the second hue (H2) are within 5 degrees of the psychometric hue angle of CIÉ of the third hue (H3).

DETAILED DESCRIPTION OF THE INVENTION The invention provides a case for the preparation of composite dental restorations. According to a preferred embodiment of the invention, a case is provided for the dental composite material for making crowns and bridges having a translucent layer on an intermediate layer on an opaque layer. The case includes a first set of pasta having a first, a second and a third pasta. Preferably, the first dough is formed from a first powder, the second dough is formed from a second powder and the third dough is formed from a third powder, for example, by mixing each powder with a polymerizable liquid. Preferably, the case includes a second set of pastes having a first, a second and a third pastes. The pastes can be formed, for example, by mixing. The first paste has a first opacity (d), a first shade (H), a first color intensity (d) and a first clarity value (L |) when they are formed in the translucent layer.The second paste has a second opacity (02), a second shade (H2), a second intensity of * color (C2), and a second clarity value (L2) when they are formed in the middle layer.The third paste has third opacity (O3), a third hue (H3), a third color intensity (C3) and a third lightness value (L3) when they are formed in the opaque layer.The third opacity (O3) is greater than the second opacity (02), which is greater that the first opacity (O ^.) The layers are hardened, for example, by curing.Preferably for each set of pastes, the third clarity value (L3) is greater than the second clarity value (L2) and the second value of clarity (L2) is greater than the first clarity value (L ^.) The differences of the clarity value between the third clarity value (L3) and the prime r value of clarity (L ^ is preferably less than 10 units of CIÉ L * a * b * and more preferably less than 5 units of CIÉ L * a * b *. Each of the first nuance (^) and the second nuance (H2) are less than 2 degrees of the psychometric nuance angle of CIÉ of the third hue (H3). According to a preferred embodiment of the invention, a color equalization system of the dental composite material is provided by measuring the reflection of visible light from the external surface of a comparative dental composite article in a plurality of wavelengths. A translucent paste is formed into a dental composite layer having an outer surface having a percent reflection for each of a plurality of visible light wavelengths. At each wavelength the reflection percent of the translucent layer is different from the reflection percent of the article by a substantially constant percentage. The invention provides a shading method with a color correlation scheme for making coordinated shades of composite materials of varying translucency. These composite materials are combined to make a dental restoration that corresponds to a reference article of tooth tone. According to the invention, greater color fidelity is provided between the materials that will be sequentially applied to form the dental composite products. According to a preferred embodiment of the invention, dental experts use at least two, and often three, composite pastes to create a crown or bridge. An opaque composite paste is useful to hide the metallic substructure. Dentine and opaque dentine composites are cured on top of opaque composites to create the client's anatomy. These last composite materials are translucent. After polymerization, the tooth should visually match the projection of the designated tone guide on a prescription from the dentist. The color coordination of the prior art has been limited to equal the color intensity and clarity of the porcelain. The color coordination of the translucent materials is dependent on the thickness of the sample unless the samples are thicker than the "infinite optical thickness". In the method and kit of the present invention all three color coordinates are used and the colors are matched with samples based on the intrinsic color or on the color in the infinite optical thickness. According to the invention to correlate the shades of the translucent composite materialscomposite materials are made nuanced with three transparencies. The infinite optical thickness of the highly transparent composite material is determined separately by making cured samples. The color coordinates and the reflectivity of the sample for the visible light transmitted to the sample at each of several individual wavelengths (preferably 10 or more wavelengths between 400 and 700 millimeters) is measured with the Datacolor photometer spectrum. Preferably these wavelengths are evenly distributed over the scale of visible wavelengths. Measurements are made on black and white backgrounds. For these measurements, the intrinsic color coordinates are determined. These coordinates approach the color in the infinite optical thickness. That is to say, at this thickness and thicker, the color coordinates and the reflectivity of the samples change very little, without interest if the background is white or black.

Next, pigments are added to one of the translucent composite pastes. The concentrations of the pigments in the samples of the composite pastes are visually adjusted (or photometrically) to match a tone guide projection. These samples are made of approximately the same thickness as the tone guide projection. After the visual equalization (or equalization of the percent reflective photometric spectrum at a plurality of wavelengths) of a translucent composite material is obtained, the more opaque or less opaque composite materials are pigmented until their intrinsic color coordinates equalize to those of the original composite material. From the color coordinates, and the calibration data for the pigments, the formulas that have the desired color coordinates are elaborated. This system predicts a color intensity of the composite material of opaque and dark dentine. The principles underlying the use of the CIÉ color coordinates and their calculation from the spectral response of a given color are known to those skilled in the art of color analysis. For example, see Billmeyer and Saitzman, PRINCIPLES OF COLOR TECHNOLOGY, second edition, John Wiley & Sons, 1981, especially pages 44-46, 80-83, and 174, and Judd and Wyszecki, COLOR IN BUSINESS, SCIENCE AND INDUSTRY, third edition, John Wiley & Sons, 1975, especially pages 139-169, for discussions of the methods used to calculate CIÉ color coordinates. The tables that give the products the functions of the standard CIÉ observer and the spectral potential for several CIÉ illuminants (for example, daylight, incandescent, and fluorescent) are available for each wavelength. These tables are used to calculate the tristimulus values for the standard sources of daylight, incandescent light and fluorescent light for the sample under evaluation.

These sets of composite materials are prepared as described above and compared with the prior art sold as Artglass Belleglass pastes. The values of clarity (L *), shade (h *) and color intensity (C *) and the differences thereof for dentin, opaque dentine and dark composite layers are for the composite formed from of a composite toothpaste system of the present invention. The hue is the angle measured from the horizontal that each point creates, graining the color coordinates a * and b * and connecting these points to the origin of the graph of b * (yellowness) against a * (redness), and it is mathematically found from equation 1. The intensity of color is the distance of each point from the origin, and is found mathematically from equation 2. Mathematically the hue and intensity of color are expressed as follows: Hue = tan "1 ( b * / a *) (1) Color intensity = (a * 2 + b * 2) (2) Consistency for hue value, color intensity and clarity is provided in composite materials made in accordance with the In this way, the invention provides previously matched shades for use in making composite products having consistent hue, color intensity and clarity The invention provides sets of color equalizing composite pastes, with a paste being the material for and The translucent composite material and the other paste being material for a composite material having a lower degree of translucency than the first paste, such that, when the composite materials are cured, the composite materials equalize in color. The products provided by the invention can be in the form of pastes.

The clarity values of the composite material layers formed from the paste according to the invention decrease from a layer formed from a very opaque paste to a layer formed from a less opaque paste for a layer formed from a less opaque pasta. The change in the value of clarity is substantially monotonic. The materials for the kits and the methods according to the invention preferably include a polymerization initiator. The polymerization of a polymerizable material, such as the monomer, for the kits, systems and methods of the invention is preferably initiated by light, heat or mixture of the components. The materials to be used according to the invention preferably include a polymerizable monomer. The polymerization initiators in the polymerizable monomers useful in the materials for the kits and methods according to the invention are disclosed in the United States Patents of DENTSPLY Nos. 4,698,373; 4,711,913; 4,814,423; and 4,863,977 each incorporated herein by reference in its entirety, and particularly for the disclosure of the same polymerization initiators and polymerizable materials including monomers. The exemplary polymerizable material for use in accordance with the invention includes polymerizable acrylates such as alkyl substituted acrylates. Preferred pastes and powders for use in accordance with the invention include pigment or pigments and / or fillers, for example, 10, 20, 40, 50 or more percent by weight of organic and / or inorganic filler particles. The exemplary polymerizable material for use in accordance with the invention includes one or more polymerization initiators, such as self-curing two-component initiators, heat-cured initiators and / or initiator photo or photo initiators for example, camforquinone.

The stable polymerization resistant to separation compositions on the shelf to make dental polymeric products is also provided. Preferably, the separation-resistant polymerizable composition includes inorganic and / or organic particulate material such as polymer, polymerizable material and a polymerization initiator system adapted to initiate the polymerization of the polymerizable material. The polymerizable composition preferably has a viscosity of about 5,000 to about 1,000,000 cps at 25 ° C. The preferably polymerizable compositions, according to the invention, are photo-polymerizable, heat-curable and / or self-curing compositions which are resistant to separation. The invention provides photo polymerizable compositions adapted for use as polymeric compositions in the manufacture of crowns and bridges. Preferably a polymerizable viscosity resistant to separation has a viscosity of about 5,000 to about 1,000,000 cps (at 25 ° C). More preferably a composition resistant to VLC separation has a viscosity of about 60,000 to about 900,000 cps (at 25 ° C). According to a preferred embodiment of the invention, the photo-polymerizable composition includes polymer particles, a polymerizable resin composition of methacrylate or acrylate with a Brookfield viscosity of about 1, 500 to 400,000 cps (at 25 ° C) and a system initiator photo: The polymerizable photo compositions have a viscosity from about 5,000 to about 1,000,000 cps (at 25 ° C). Preferably, a particulate polymer filler and / or an inorganic filler is added to a liquid or semi-solid polymerizable material to form a separation resistant composition having a viscosity of about 5,000 to about 1,000,000 cps. The particulate polymer preferably includes thermoplastic and / or thermal hardening polymer particles, such as polyolefins (eg, polyethylene, polypropylene, etc.), polyacrylates, polymethacrylates (or poly (meth) acrylate copolymers), or nylon. Preferably, the polymer used in this composition is crosslinked and particulate, such as the copolymers of the methacrylate or particulate acrylate compounds. Preferably the particulate polymer is a mixture of a crosslinked polymer of methyl methacrylate and a dimethacrylate, such as ethylene glycol dimethacrylate, and a methyl methacrylate homo polymer. The crosslinked, particulate copolymer used in a preferred separation resistant composition is poly (methyl methacrylate-co-ethylene glycol dimethacrylate) formed from 90 to 99.95% by weight of methyl methacrylate and from about 0.05 to 10% by weight of ethylene glycol dimethacrylate. More preferably the crosslinked, particulate copolymer is formed from 99 to 99.9% by weight of methyl methacrylate and from about 0.1 to 1% by weight of ethylene glycol dimethacrylate. The particulate polymer can be included in the polymerizable composition of the invention. In a preferred embodiment of the invention, the particulate polymer is from about 2 to about 60% by weight of the total composition, more preferably it is from 10 to 50% by weight, most preferably it is from 20 to 40% by weight. Preferably the particle size scale of the particulate polymer used in the present invention is from about 2 to about 200 microns. More preferably, the scale of the particle size of the polymer is about 10 to 150 microns and most preferably the scale of the particle size of the polymer is about 20 to 100 microns. As the average particle size of the polymer shifts towards the upper end of this scale (from about 150 to 200 microns), the polymer content of the polymerizable composition is increased (approaching 50 to 60% by weight) to produce a polymerizable composition with a viscosity of 5, 000 to 1, 000,000 cps at 25 ° C. Preferably, the polymerizable material of the composition of the invention comprises a polymerizable, ethylenically unsaturated material, such as methacrylate or acrylates. Murphy and others in the United States patent NO. 4,844,144 discloses a suitable polymerizable material. Preferably the polymerizable material is composed of methacrylate and polymerizable urethane acrylates and esters of acrylic and methacrylic acids. Preferably, the polymerizable material comprises a mixture of urethane (meth) acrylates and has a density of about 1.10 to about 1.35 grams per milliliter (g / ml) at 25 ° C for use with particulate polymers preferably of polymethacrylate and / or copolymers thereof. Preferably, the polymerizable mixture has a density of at least 1.12 g / ml at 25 ° C, and more preferably the polymerizable material has a density of at least 1.15 g / ml (at 25 ° C). The viscosity of the polymerizable material is preferably from about 4,000 to about 300,000 cps (at 25 ° C), and more preferably the viscosity of the polymerizable material is from about 10,000 to about 200,000 cps (at 25 ° C). Preferably, the content of the polymerization initiating system of the polymerizable composition is from 0.2 to 7.5% by weight, or more preferably it is from 0.5 to 5% by weight, or even more preferably it is from 0.7 to 2.0% by weight, and is most preferably about 1.0% by weight. Preferably, the difference in hue between a very opaque layer and a very opaque layer and a less opaque layer is less than 2, and most preferably less than 1 degree. The invention is now described with reference to the specific examples: EXAMPLE 1 A paste material is made to be used according to the invention as set forth in the following examples: 33.3 grams of the monomeric reaction product of 2 moles of hydroxyethyl (meth) acrylate and 1 mole of 2,4-trimethylethylethylene diisocyanate are mixed. , 9.18 grams of glass particles with silane, 19.16 grams of pyrogenic silica, 0.41 grams of tert-butyl-perisononanoate, 0.4 grams of benzopinacol, 0.15 grams of 2,4-dihydroxybenzophenone and 37.4 grams of acrylate polymer particles to form a paste . Three parts of the paste are mixed separately with pigments and placed between three labeled containers. The first portion of the material in the first labeled container is mixed with pigments to provide a material having a first opacity (O ^ and a first clarity value (L ^ when they are formed in a less opaque layer. the second labeled container is mixed with pigments to provide a material having a second opacity (02) and a second clarity value (L2) when formed in a less opaque layer.The third part of the material within the third labeled container is mixed with pigments to provide a material having a third opacity (O3) and a third clarity value (L3) when they are formed in the most opaque layer.A part of the first material, the second material and the third material are formed by brushing and paving The opacity (O3) is greater than the second opacity (O2), the second is opaque and opaque, each layer having a thickness of less than 1.5 millimeters. pacity (02) is greater than the first opacity (O ^. The third brightness value (L3) is greater than the second brightness value (L2). The second brightness value (L2) is greater than the first brightness value (Li). The third material is formed in the very opaque layer on the ceramic substrate (alternatively a metallic or fiber reinforced substrate that can be used) and heat cured. The second material is formed in the less opaque layer on the very opaque and heat cured layer. The first material formed in the less opaque layer on the less opaque layer and cured with heat to form a crown and a bridge.

EXAMPLE 2 An opaque paste is made by stirring 7.1 grams of silanated titanium dioxide, 5.8 grams of silanated zirconium dioxide, 42.9 grams of urethane dimethacrylate, 16 grams of triethylene dimethacrylate, 3.2 grams of dipentaerythritol pentacrylate phosphoric acid ester (PENTA) , 4.8 grams of terbutyl peroxybenzoate (t-BPD) (Lucirin LR 8893 X) sold by Bayer, 1.9 grams of 1, 1, 7-trimethyl- (IS) bicyclo (2.2.1) eptane-2,3-dione ( camforquinone), 6.7 grams of smoked silica, 3.14 grams of methacrylic acid, 6.74 grams of dimethylamino-neopentilacrylate and 1.6 grams of pigments.

EXAMPLE 3 The less opaque paste (dentin) is made by stirring 11.1 grams of a mixture of 32 parts of triethylene glycol dimethacrylate also known as 2-propenoic acid, 2-methylene-1,2-ethanediyl-bis (oxy-2) ester. , 1-ethanediyl) (TEGDMA), 32 parts of cyclodi-2,2'-bis ((4- [3-methacryloxy-2 (1, 12-dioxa-2,11-dioxo-3, 10-diazadodecane) propoxyphenyl]) propane and 4 parts of 2-propenoic acid, 2-methyl- (1-methylethylidene) bis (4,1-fanalyenoxy-2,1-ethanediyl) ester (bis GMA), 11.1 grams of a 55-part mixture of cyclodi-2,2'-bis ((4- [3-methacryloxy-2 (1, 12-dioxa-2,11-dioxo-3,10-diazadodecane) propoxyl] phenyl]) propane and 45 parts of 2 -propenoic ester, 2-methyl-1,2-ethanediyl-bis (oxy-2, 1-ethanediyl) ester (TEGDMA), 0.0058 GRAMS OF 2,6-Bis (1,1-dimethylethyl) -4-methylphenol ( BHT), 0.046 grams of 1,4-diethyl-2,5-dihydroxy-dibenzoate, 0.23 grams of methanone, (2-hydroxy methoxyphenyl) phenyl, 0.023 grams of bicyclo (2-2-1) heptane-2,3- dione 1, 1, 7-trimethyl-. (IS) (CQ), 0.009 grams of ethyl-4-N, N-dimethylaminobenzoate (EDAB), 75.2 grams of aluminum borosilicate barium fluoride (7726), and 2.32 grams of smoked silica. Table 1 compares the clarity value, and the differences in color intensity and hue between the dentine and opaque composites for ArtGlass, Beleglass, Lucipast with Example 2 (opaque) and Example 3 (dentin). Each opaque paste is coated on a metallic button, polymerized and then measured for the clarity value (L *), the color intensity (C *) and the hue (less opaque dentin: CIÉ color coordinates). Each less opaque paste (dentin) is formed into a 3 mm thick button, polymerized and then measured for the value of clarity, color intensity and hue. Table 1 Variation in the intrinsic colors between the opaque and dentine composite materials Material? L *? C * amatiz (°) ArtGlass 13.5 0.3 -4.1 BelleGlass 21.6 12.9 -3.0 Licupast 16.4 -0.7 -4.0 Examples 2 and 3 minor minor minor (materials compounds that what opaque and dentine) 2.5 5 1 It should be understood that although the present invention has been described in considerable detail with respect to certain specific embodiments thereof, it should not be considered limited to these modalities but may be used in other ways without departing from the spirit of the invention and of the invention. reach the appended claims.

Claims (10)

1. A method for making a polymeric dental product, which has a substantially monotonic decrease in the value of clarity between the layers from a very opaque layer underlying a less opaque layer placed below a less opaque layer, comprising: providing a first material enclosed by a first container labeled and having a first opacity (OI), and a first value of clarity (L ^ when a lesser opaque layer is formed, a second material enclosed by a second labeled container having a second opacity (O2) and a second clarity value (L2) when formed in said less opaque layer, and a third material enclosed by a third labeled container having a third opacity (03) and a third clarity value (L3) when they form in said very opaque layer, each of said layers less opaque, more opaque, more opaque and very opaque not being thicker than 1.5 mm, the third opacity (O3) being greater than said second opacide d (O2), said second opacity (O2) being greater than said first opacity (O ^, said third clarity value (L3) being greater than said second clarity value (L2) and said second clarity value (L2) being greater than said first clarity value (L ^, forming said third material in said very opaque layer on a substrate, forming said second material in said less opaque layer on said very opaque layer, forming said first material in said less opaque layer on said less opaque layer.

2. The method according to claim 1, wherein said third opacity (O3) is 100 percent opaque.

3. The method according to claim 2, wherein said second opacity (O2) is from 94 percent to 99 percent opaque.

4. The method according to claim 1, wherein said third clarity value (L3) and said first clarity value (Li) have a difference in clarity value of less than 10 units from Commission International de l'E'Clairage (CIÉ) L * a * b. The method according to claim 1, further comprising hardening said first material, hardening said second material, and hardening said third material. The method according to claim 1, wherein said first material comprises polymerizable material, said second material comprises polymerizable material, and said third material comprises polymerizable material. The method according to claim 1, wherein said first material comprises an initiating photo, said second material comprises an initiating photo, and said third material comprises an initiating photo. The method according to claim 1, wherein said first material comprises an initiator photo and a polymerizable material, said second material comprises an initiator photo and a polymerizable material, said third material comprises an initiator photo and a polymerizable material. The method according to claim 1, wherein said first material is a liquid, paste or powder, said second material is a liquid, paste or powder, and said third material is a liquid, paste or powder. The method according to claim 1, wherein said first material further comprises a polymerizable material and further comprising polymerizing said polymerizable material into said first material to form the first polymeric material. The method according to claim 1, wherein said second material further comprises a polymerizable material and further comprises polymerizing said polymerizable material in said second material to form the second polymeric material. The method according to claim 1, wherein said third material further comprises a polymerizable material and further comprises polymerizing said polymerizable material in said third material to form the third polymeric material. 13. A case for making a dental compositeH. , which has a substantially monotonic change in the value of clarity between the layers for a very opaque layer underlying a less opaque layer placed under a less opaque layer, comprising: a first material enclosed by a first labeled container and having a first opacity (O ^, and a first clarity value (Li) when a second material enclosed by a second labeled container having a second opacity (02) and a second clarity value (L2) is formed in said less opaque layer; ) when formed in said less opaque layer, and a third enclosed by a third labeled container having a third opacity (O3) and a third clarity value L3) when formed in said very opaque layer, each of the layers less opaque, more opaque and very opaque not being thicker than 1.5 mm, said third opacity (O3) being greater than said second opacity, said second opacity (O2) being greater than said first opacity (Oi), said third value of clarity (L3) being greater than said second clarity value (L2) and said second clarity value (L2) being greater than said first clarity value (L |). The kit according to claim 13, wherein said first material is a polymerizable material having at least one polymerizable compound, said second material in a polymerizable material having at least one polymerizable compound and said third material is a polymerizable material having at least one polymerizable compound. 1

5. The kit according to claim 13, wherein said first material is a polymerizable paste having at least one polymerizable compound, said second material is a polymerizable paste having at least one polymerizable compound and said third material is a polymerizable paste having at least one polymerizable compound. The kit according to claim 13, wherein said first material is a polymerizable powder having at least one polymerizable compound, said second material is a polymerizable powder having at least one polymerizable compound and said third material is a powder polymerizable having at least one polymerizable compound. 17. A method of making a product that has substantially no change in the hue of a very opaque layer to the less opaque layer and a monotonic decrease in clarity value between the layers from a very opaque layer to a less opaque layer placed below of a less opaque layer, the very opaque layer underlying the less opaque layer comprising: providing a first material enclosed by a first labeled container and having a first opacity (O ^, and a first hue (H ^, when formed in said less opaque layer, a second material enclosed by a second labeled container having a second opacity (O2) and a second hue (H2) when formed in said less opaque layer, and a third material enclosed by a third labeled container having a third opacity (03) and a third shade (H3) when formed in said very opaque layer, each of the layers less opaque, more opaque and very opaque not being thicker than 1.5 mm, said third opacity (03) being may or that said second opacity (O2), said second opacity (O2) being greater than said first opacity (O ^, said third hue (H3) being greater than said second hue (H2) and said second hue (H2) being greater than said first hue (Hi), forming said third material in said very opaque layer on a substrate, forming said second material in said less opaque layer on said very opaque layer, forming said first material in said less opaque layer on said less opaque layer. 18. The method according to claim 17, wherein said third opacity (O3) is 100 percent opaque. The method according to claim 18, wherein said second opacity (02) is opaque from 94 percent to 99 percent. 20. The method according to claim 17, wherein said third clarity value (L3) and said first clarity value (Li) have a difference in clarity value of less than 10 units from International Commission of 1'E'clairage (CIÉ) L * a * b . The method according to claim 17, further comprising hardening the first material, said second material, and said third material. 22. The method according to claim 17, wherein said first material comprises polymerizable material, said second material comprises polymerizable material, and said third material comprises polymerizable material. The method according to claim 17, wherein said first material comprises an initiating photo, said second material comprises an initiating photo, and said third material comprises an initiating photo. The method according to claim 17, wherein said first material comprises an initiator photo and a polymerizable material, said second material comprises a photo initiator and a polymerizable material, said third material comprises an initiator photo and a polymerizable material. 25. The method according to claim 17, wherein said first material is liquid, paste or powder, said second material is a liquid, paste or powder, and said third material is a liquid, paste or powder. 2

6. The method according to claim 17, wherein said first material further comprises a first polymerizable material and polymerizing said first polymerizable material in said first material to form the first polymeric material, said second material further comprising a second polymerizable material and polymerizing said second polymerizable material in said second material for forming the second polymeric material, and said third material further comprises a third polymerizable material and polymerizing said third polymerizable material in said third material to form the third polymeric material.