JP2007521228A - Polyorganosiloxane dental impression material - Google Patents

Abstract

A dental impression material comprising polyvinyl siloxane and a surfactant such that the surfactant has a surface contact angle with the composition such that the impression material has a surface contact angle with water that is less than about 50 degrees after about 3 minutes. Dental impression material that imparts wettability to the skin.

Description

  The present invention is generally directed to polyorganosiloxane dental impression materials. More particularly, the present invention is directed to the above materials having improved physical properties including improved wetting and tear strength. Specifically, the present invention uses a silicone glycol surfactant.

  The present invention is directed to improvements in room temperature polymerizable polyorganosiloxanes that have excellent dimensional stability when cured or solidified. More particularly, the present invention is generally directed to improvements in two-component compositions, where one component contains a vinyl group that can participate in an addition reaction with an organopolysiloxane having a silicon-bonded hydrogen atom. Having an organopolysiloxane. The second component includes a catalyst that can promote the addition of a hydrogen atom bonded to a silicon atom via a vinyl group.

  A major area in which some of these room temperature curable polyorganosiloxane compositions are used is dentistry. Such materials are commonly used as impression materials to ensure an approximate form of hard and soft tissue in the oral cavity that supports the subsequent fine finish of crowns, bridges, dentures and other oral restorations. For dental applications, extraordinary fidelity of structure reproducibility is required to ensure excellent fidelity, such as the fit of an oral prosthesis. In this connection, dimensional changes during the curing of the impression material must be avoided. In addition, there should be no significant irregularities, scratches, holes, or other defects on the surface of the replica or oral prosthesis. This means that the moldings and prostheses derived from the above impressions have good surface quality in order to fit properly, achieve good adhesion and avoid irritation of delicate oral structures Because there should be no holes or irregularities. These polyorganosiloxanes are also useful in other areas where precise reproducibility is important, such as metrology science, SEM laboratory processing, and even jewelry processing.

  Many difficulties arise when using polyorganosiloxanes as dental impression materials. First of all, the tear strength tends to be low. When trying to take an impression effectively, it is necessary to be able to easily remove the impression without tearing while maintaining details from the dentition, especially in the thin border region. Conventionally, various types of fillers have been added to improve tear strength. This addition can result in an improvement of about 10%, but such an improvement has proved insufficient.

Paradiso, in WO 93/17654, incorporates a polyfunctional polysiloxane component containing tetrafunctionality into an impression material, and in accordance with the length of the main component of the polysiloxane that is end-capped with linear vinyl, particularly in the resulting cured impression material substrate. And improving the tear strength by adding additional crosslinks. This Paradiso composition contains SiOH groups capped with Me ₃ Si units forming pendants from the molecule. These pendants merely provide mechanical or physical linkages between the linear polysiloxane chains. This solution is non-chemical and has a poor crosslink density.

Voigt et al., In EP0522341A1, describe the use of “QM” resin as a means to promote and increase cross-linking and to form an occlusal acquisition device in a very short processing time of 35 to 45 seconds. . These resins have a tetrafunctional SiO _4/2 as Q and a monofunctional unit R ₃ SiO _1/2 as M (R is vinyl, methyl, ethyl or phenyl) or similar trifunctional or bifunctional Includes building blocks such as units. Voigt mentions that low elastic deformation elastomers with high toughness and hardness result. However, the above materials lack flexibility, have a low elongation rate, and are not suitable for obtaining an impression. The increased cross-linking rate of the QM resin also makes the processing time very limited and unsatisfactory.

  Another major well-known problem with polyorganosiloxane impression materials is caused by their inherent hydrophobicity. This characteristic makes it difficult to produce a replica of the oral tissue that is hard and soft, because the cavity of the oral cavity is wet and often contaminated by saliva or blood. To. Due to the hydrophobic nature of the impression material, it is often possible to lose surface details at the critical surface of the dentition.

Many improvements in polyorganosiloxane impression materials have focused on adding surfactant components to the dental impression material to reduce the hydrophobicity of the polysiloxane and make the composition more hydrophilic. For example, Bryan et al. Described in US Pat. No. 4,657,959 that an ethoxylated nonionic surfactant containing a siloxane or perfluoroalkyl solubilizing group was added to obtain a water contact angle of less than about 65 degrees after 3 minutes. is doing. Although surfactants containing hydrocarbyl groups have been mentioned, including ethyleneoxy groups, to dissolve or disperse the surfactant in the silicone prepolymer, the results obtained appear to be less than optimal.
WO93 / 17654 EP0522341A1 U.S. Pat. No. 4,657,959 Gower, "Handbook of Industrial Surfactants", 1993 ADA Standard 19: Non-aqueous elastomer impression material (1976; amended in 19a of 1982)

  In short, polyorganosiloxane impression materials provide improved usage of the composition for taking impressions of hard and soft tissues in the oral cavity by providing adequate working time, tear strength and wettability. Therefore, there is still a need for improved tear strength and wettability.

The novel polyvinylsiloxane impression material is useful in low and high viscosity impression materials that record hard and soft tissues in the mouth. This novel impression material has two components, a platinum catalyst and a vinyl polysiloxane material. This two-component polymerizable organosiloxane composition for the production of dental impressions, in which one component contains a polymerization catalyst,
(A) a QM resin containing a vinyl group;
(B) a linear vinyl-terminated polydimethylsiloxane solution that forms a dispersion having a vinyl content of about 0.16-0.24 mmol / g with the QM resin;
(C) an organohydrogenpolysiloxane for crosslinking the vinyl group;
(D) an organoplatinum complex catalyst for accelerating the polymerization of each component;
(E) an emulsifying plasticizer for the complex catalyst;
(F) an amount of retarder component sufficient to temporarily delay the initiation of the polymerization;
(G) a filler (filler); and (h) the composition includes a surfactant that imparts wettability such that the surface contact angle of the composition with water becomes less than 50 degrees after 3 minutes. .

  The present invention also provides a polyorganosiloxane impression material using a silicone glycol surfactant that achieves a water contact angle of less than about 10 degrees in 30 seconds. A preferred surfactant is PEG-8 methicone such as, for example, Masil SF 19, commercially available from BASF. According to one embodiment of the present invention, a contact angle of 2 degrees was achieved in 30 seconds, as will become apparent below.

  Preferably, the dispersion of (a) and (b) has a viscosity of about 5,000-60,000 cps. The dispersion of (a) and (b) can include a plurality of dispersion components having a desired viscosity and QM resin content. Preferably, the QM resin-containing dispersion comprises a first dispersion component having a viscosity of about 5,000 to 7,000 cps; and a second dispersion component having a viscosity of about 45,000 to 60,000 cps; The QM resin constitutes about 20-25% by weight of each dispersion.

Preferred QM resins are SiO _4/2 units and R ¹ R ² ₂ SiO _1/2 units, wherein R ¹ is unsaturated, preferably vinyl, R ² is alkyl such as methyl, ethyl, phenyl, Polyorganosiloxanes, such as aryl). More preferably, the QM resin has the formula: ## STR1 ##.

  The retarder component of the composition is a low molecular weight vinyl functional fluid that is a linear or cyclic polysiloxane occupying an amount of at least about 0.030% by weight of the composition. Preferably, the retarder component comprises fluid 1,3-divinyl, dimethyldisiloxane in an amount of about 0.030 to 0.10% by weight of the composition.

  The composition emulsifies the desired handling and flow characteristics to the complex catalyst to match the characteristics of the second component so that it can advantageously form a composition suitable for taking a dental impression. Contains a plasticizer. Preferably, the plasticizer comprises about 0.5 to 2.0% by weight of the catalyst component alkyl phthalate, most preferably octyl benzyl phthalate.

  The filler component of the present invention comprises from about 15 to about 45% by weight of the composition, preferably from about 20 to about 40% by weight of the filler mixture.

  An important component of the composition according to the present invention is a surfactant that imparts wettability, preferably having an HLB of about 8-11 and a pH of about 6-8. The most preferred surfactant is nonyl phenoxy poly (ethyleneoxy) ethanol having an HLB of about 10.8, which is a nonionic surfactant.

  After polymerization, the composition according to the invention has a tear strength of 270 to 300 PSI (1.86 to 2.06 MPa), and its contact angle with water is less than about 50 degrees in 3 minutes.

  Exemplary polymerizable polysiloxane compositions of the present invention generally comprise an organopolysiloxane further comprising a tetrafunctional vinyl polysiloxane resin having at least about 2 vinyl groups per molecule dispersed therein. An organohydrogenpolysiloxane having at least about 2 hydrogen atoms bonded to at least 2 silicon atoms per molecule; to promote the addition of the silicon atoms bonded to the hydrogen atoms to the polysiloxane vinyl group; A catalyst containing an emulsifying plasticizer; a filler; a low molecular weight retarder composition for delaying the onset of polymerization; and an emulsifying surfactant that imparts wettability to the impression material.

  The composition of the present invention is divided into two components. The first component (for convenience, referred to as “base paste”) includes the vinyl organopolysiloxane dispersion, the organohydrogenpolysiloxane, the filler, and a portion of the surfactant. The second component of this two-component composition is called “catalyst paste”, and the second part of the vinyl polysiloxane is replaced with a catalyst for promoting the addition reaction, the emulsifying plasticizer, and during the polymerization. Contains scavengers for hydrogen released, and usually with additional amounts of fillers and pigments.

  Various organopolysiloxanes having at least about 2 vinyl groups per molecule to be included in the dental polysiloxane composition of the present invention for forming a dispersion containing the tetrafunctional vinyl polysiloxane are as follows. Are known. Each of these materials can have a higher or lower concentration depending on the practice of the invention. Preferred for use in the present invention is a chain vinyl terminated polydivinylsiloxane, preferably divinylpolydimethylsiloxane. As such polymers, those having various viscosities and various average molecular weights corresponding thereto are sold. These materials are preferably selected to have a viscosity suitable for the conditions encountered by the resulting silicone material.

  Important dispersions have viscosities in the range of 5,000-60,000 cps. In practice, it is preferred to provide a composition having the desired thixotropy and viscosity using a blend of dispersed polymers having different viscosities and physical properties.

  The important dispersions are in two viscosity ranges: (1) a first dispersion having a viscosity of about 5,000 to 7,000 cps; and (2) a second having a viscosity of about 45,000 to 65,000 cps. Preferably, it is formed of a dispersion of It is convenient to provide a polysiloxane oligomer having a methyl substituent for this purpose, but other substituents can also be included in the composition according to the invention. Thus, alkyl, aryl, halogen and other substituents can be included at higher or lower concentrations as part of the vinyl polysiloxane that is useful. Those skilled in the art will be able to determine which polysiloxane materials are suitable for a particular application from the considerations discussed above.

Tetrafunctional polysiloxanes, known and known in the art as QM resins, provide improved tear strength to the polymerized impression composition due to the resulting increased polymerized crosslink density. As is known, the QM resin comprises tetrafunctional SiO _4/2 units; and R ¹ R ² ₂ SiO _1/2 , where R ¹ is unsaturated, preferably vinyl, R ² is an alkyl unit such as methyl, ethyl or phenyl, aryl, etc.). In a preferred composition, R ¹ is vinyl and both R ² are methyl. The most preferred composition is represented by the formula: ## STR2 ##.

  The QM resin provides a vinyl concentration in the dispersion containing the vinyl terminated polydivinylsiloxane of at least about 0.16 mmol / g. Preferably, the vinyl concentration is 0.16-0.24 mmol / g. The amount of QM resin is preferably about 20-25% by weight of the dispersion. Such dispersions are available from Miles, Inc. of Pittsburgh, Pennsylvania. Sold by. Other QM resin formulations may be used including those that are "undiluted" or dispersed in a carrier other than the suitable fluid polydivinylsiloxane.

  An important element of the present invention is a retarder component that delays the onset of polymerization of the QM resin / dispersion to provide sufficient working time to use the composition. This retarder, as it is consumed, retards polymerization that proceeds otherwise too fast. A preferred retarder solution in a preferred important impression material is 1,3 divinyldimethyldisiloxane at a sufficient concentration level to act as a retarding function, which is at least about 0.03% by weight of the composition, preferably about 0%. Within the range of 0.03 to 0.10% by weight. This preferred amount is in contrast to small amounts such as 0.0015 to 0.020% by weight which are typical amounts used in PVS systems for composition stabilization. Other suitable retarders are any low molecular weight vinyl functional materials such as chain and cyclic polysiloxanes that are first consumed during polymerization to retard cure as appropriate and desired.

  Organohydrogenpolysiloxanes useful in the practice of the present invention are well known to those skilled in the art. What is required is the use of polysiloxanes in which hydrogen atoms are bonded directly to silicon atoms and that they have suitable viscosity and other physical properties. Substituents in the molecule such as alkyl (especially methyl), aryl and halogen can be used as well. However, it is necessary that such substituents do not inhibit the platinum catalyst addition reaction. In addition, the molecule used preferably has at least two silicon-bonded hydrogen atoms per molecule. Polymethylhydrogensiloxane having a viscosity in the range of about 35-45 cps is preferred.

  Platinum catalysts are preferred as useful catalysts for catalyzing the reaction of silicon atoms (bonded to hydrogen atoms) with vinyl groups of vinylpolysiloxane molecules. In this respect, it is preferred to use a platinum compound such as chloroplatinic acid, preferably as a mixture or complex with one or more vinyl compounds, in particular vinyl polysiloxanes. While such compounds have been found to be preferred, other catalysts are also useful. Accordingly, platinum metal is similarly useful along with other noble metals such as palladium and rhodium and their complexes and salts. However, platinum is highly preferred for dental use from the standpoint of toxicological acceptability.

The composition according to the invention also comprises a mixture of fillers, preferably hydrophobic fillers. A variety of inorganic hydrophobic fillers such as silica, alumina, magnesia, titania, inorganic salts, metal oxides, and glass can be used. However, it is preferred to use the silicone form. According to the invention, it has been found preferable to use a mixture of silicones, for example, crystalline silicon dioxide such as powdered quartz (4-6 mu); amorphous such as diatomaceous earth (4-7 mu). And those derived from silylated fumed silica such as Cab-o-Sil TS-530 (160-240 m ² / g) manufactured by Cabot Corporation. The size and surface area of each of the above materials are adjusted to control the viscosity and thixotropic properties of the resulting composition. Some or all of each of the above hydrophobic fillers are surface treated with one or more silanizing agents or “roughening” agents, as is well known to those skilled in the art. Such silanization can be accomplished using known halogenated silanes or silazides. The filler is preferably present in an amount of from about 15 to about 45% by weight of the composition to form an impression composition that is polymer rich and thus has improved flowability. More preferably, the filler is about 35-40% by weight of the composition. A preferred filler mixture comprises 14-24% by weight crystalline silicon dioxide, 3-6% by weight amorphous silicon dioxide and 4-8% by weight silanated fumed silicon dioxide. The most preferred filler is about 19% cristobalite with a particle size of about 4-6 mu, about 4% diatomaceous earth with a particle size of about 4-7 mu and about 6% of silanized fumed silica with about 160-240 m ² / g. .

A chemical system can be employed to suppress or reduce the release of hydrogen gas commonly generated as a result of vinyl polymerization. Thus, the composition may include finely divided platinum metal that looks for and incorporates such hydrogen. Such Pt metal can also be deposited on any salt that is substantially insoluble and has a surface area between about 0.1 and 40 m ² / g. Suitable salts include barium sulfate, barium carbonate and calcium carbonate of appropriate particle size. Other base materials include diatomaceous earth, activated alumina, activated carbon and the like. Inorganic salts are particularly preferred in that they provide stability to the material obtained by incorporating them. On such a salt, platinum metal is dispersed in an amount of about 0.2-2 ppm based on the weight of the catalyst component. It has been found that the use of platinum metal dispersed on inorganic salt particles substantially eliminates or reduces hydrogen gas evolution during curing of dental silicone.

  An important improvement of the present invention is a PEG-8 methicone surfactant that imparts wettability as indicated by a surface contact angle with water of less than 50 degrees in 3 minutes, more preferably less than about 10 degrees in 30 seconds. In the composition. The unpredictable results from the choice of surfactant provide great clinical benefits, a wetting contact angle of less than 10 degrees is achieved in less than about 30 seconds and is reduced during use of the composition, In contrast to prior art polyvinyl siloxane, surfactant formulations which remain below 10 degrees and require more time to fully wet. This high wetting rate of the composition according to the invention is particularly advantageous during the impression taking process and is illustrated using the figures.

  In FIG. 1, the wet contact angle expressed in degrees as a function of time (minutes) is compared between the polyvinylsiloxane composition of the present invention and the prior art composition. Curve A is the composition of the present invention and shows that the wetting contact angle is about 50 degrees after 2 minutes of mixing the substrate component and the catalyst component. FIG. 1 shows that good wettability is achieved quickly and increases further at a fast rate during the effective use time of the impression-taking material of about 3.5 minutes. Curves B and C are impression materials of polyethers according to the prior art and conventional polyvinylsiloxanes, respectively. FIG. 2 shows the change in the viscosity of the impression material as a function of time for the composition of the present invention (curve A) and the above prior art compositions (curves B and C). This shows the progress of the polymerization process after mixing, and together with FIG. 1, shows that the increase in wettability of the composition of the present invention occurs during the critical working time of the impression material. This is an important advantage over the system.

  The surfactants in the present invention can be cationic, anionic, amphoteric, or nonionic. A key criterion for selection is that the Hydrophobic Lipophilic Balance (HLB) value (see Gower, “Handbook of Industrial Surfactants” 1993) must be in the range of 8-11. As is well known, the higher the HLB value, the more hydrophobic the material. Further, the pH of the surfactant should be in the range of 6-8 to prevent side reactions that may be detrimental to the polymerization of the impression material. A preferred surfactant is non-ionic and contains nonylphenoxypoly (ethyleneoxy) ethanol with an HLB value of 10.8 and is sold by Rhone-Poulenc of Cranbury (NJ) as Igepal CO-530. In comparison, with respect to the above-mentioned U.S. Pat. No. 4,657,959 to Bryan et al., Igepal CO-630 has an HLB value of 13.0 and is different in structure from CO-530 (the number of CO-630 repeat units is 9 and that of CO-530 is 6) has been found to be ineffective, indicating the criticality of the above HLB range.

  A preferred surfactant is PEG-8 methicone, commercially available from BASF.

  The composition according to the invention can comprise plasticizers which advantageously modify the handling and flow properties of the impression material, in particular the catalyst component. A preferred emulsifying plasticizer is octylbenzyl phthalate. Other phthalate esters are also useful.

  With respect to the composition of the present invention, preferred colors can be obtained by adding various pigments. Such pigments are well known and include various pigments such as titanium dioxide.

  The two-component composition prepared according to the present invention is used in the same way as conventional impression materials. Thus, approximately the same amount of base paste and catalyst paste are mixed well and pressed against the dentition and other locations in the oral cavity for a time sufficient to polymerize or cure. Once the composition is substantially cured, it can be removed from the mouth and other surfaces and used to make casts, etc., from which subsequent cast surface reproductions are prepared.

  As will be appreciated by those skilled in the art, for dental silicone materials, it is important that they can be stored for a fairly long period of time at an appropriate storage temperature in order to maximize their market utility. Therefore, it is necessary that the material does not cause deterioration in physical properties or substantial change in working time or curing time during the storage period. In this regard, it is now possible to measure the storability of materials by accelerated storage tests employing high ambient temperatures.

  Some of the embodiments of the present invention will be described below. Many other compositions and formulations besides those described below could be made within the spirit of the invention. The following examples are not intended to limit the invention, but are provided for illustration.

The two-component composition of the present invention is blended as a base paste component and a catalyst paste component. The ingredients of each component are mixed under a 65 mm Hg vacuum with a double planetary mixer having a mixing vessel heated using 45 ° C. to 50 ° C. circulating water.
Base paste component

When preparing the base paste, first add all of the organohydrogenpolysiloxane to the mixing pot, then add the additional QM dispersion and filler components, and continue mixing until the whole is uniform To do. Remove the finished base paste into the storage container.
Catalyst paste component

The catalyst paste components are blended and mixed under the conditions described above and in the apparatus. Platinum catalyst, 1,3-divinyldimethyldisiloxane, QM resin dispersion, filler and pigment are additionally added to the mixing pot and mixed until a uniform material is obtained. Next, the catalyst paste thus formulated is taken out into a storage container.
The composition of each component is shown in the table below. In the table, the amounts are weight percent of each component.

  As described in Example 1, a two-component composition of the invention having the composition shown in the table below is made by first making a base paste and then a catalyst paste.

  As described in Example 1, a two-component composition of the invention having the composition shown in the table below is made by first making a base paste and then a catalyst paste.

  As described in Example 1, a two-component composition of the invention having the composition shown in the table below is made by first making a base paste and then a catalyst paste.

  As described in Example 1, a two-component composition of the invention having the composition shown in the table below is made by first making a base paste and then a catalyst paste.

  As described in Example 1, a two-component composition of the invention having the composition shown in the table below is made by first making a base paste and then a catalyst paste.

  As described in Example 1, a two-component composition of the invention having the composition shown in the table below is made by first making a base paste and then a catalyst paste.

  As described in Example 1, a two-component composition of the invention having the composition shown in the table below is made by first making a base paste and then a catalyst paste.

  As described in Example 1, a two-component composition of the present invention having the composition shown in the table below is made by first making a base paste and then a catalyst paste.

  As described in Example 1, a two-component composition of the invention having the composition shown in the table below is made by first making a base paste and then a catalyst paste.

  10 g of each representative sample of the above examples were mixed in equal parts and the properties of the mixture and the resulting polymer composition were tested. The table below shows the measurement results. The first five properties shown are tested according to ADA standard 19: non-aqueous elastomeric impression material (1976; amended in 19a of 1982).

The following procedure was used to obtain the tensile tear strength, percent elongation and elastic modulus for each example.
Equal parts of the base component and catalyst component are mixed and the sample or test specimen is a 1.5 mm thick, 20 mm × 11 mm I-shaped cavity with a top arm 8 mm deep and a central I portion 5 mm wide Place in the sample mold you have. The filled mold is clamped between two stainless steel plates and the assembly is placed in a 32 ° C. water bath. At 6 minutes from the start of mixing, the assembly is removed from the bath. Remove the mold, remove the specimen from the mold and remove all flash from the specimen. Ten minutes after the start of mixing, the specimen is clamped in the Instron Model 1123 specimen specimen grip in stretch mode. The Instron is attached to a Microcon II microprocessor programmed to calculate tear strength [psi], percent elongation, and modulus. At 11 minutes, the specimen is stressed by Instron at a rate of 10 mm / min until the specimen reaches peak failure (the maximum load is set at 5 kg). This was repeated for five test pieces, and the obtained statistical evaluation results are shown in Table 1.

  The wet contact angle was measured for each example as follows. 1 g of base paste and 1 g of catalyst paste were mixed until uniform (about 30 seconds). 0.5 g of the mixed paste is placed between two polyethylene sheets (Dentsilk) and pressed flat to a thickness of about 2-3 mm using a glass plate. The specimen was allowed to stand until it cured (about 15 minutes). The polyethylene sheet is carefully removed so as not to touch the surface of the specimen, and the specimen is placed on a table of a dinometer, a well-known device for contact angle measurement. The eyepiece reticle is adjusted to the horizontal and vertical planes of the test piece surface, and a water drop is dropped on the test piece surface and the stopwatch is operated at the same time. The internal contact angle at the water / test piece interface from 1.5 minutes to 3.5 minutes was measured in degrees using a dimeter scale and recorded for each test piece is shown in Table 1 below. In the table below, NA means impossible to measure.

  Examples 1-3 are preferred compositions. Example 1 is suitable for dispensing from a tube and kneading. Example 2 is most preferred for cartridge dispensing and static mixing. Example 3 describes a composition of the present invention suitable for forming a low viscosity composition suitable for either tube dispensing or cartridge dispensing.

  The composition of Example 4 had a high viscosity, showed vigorous gas evolution, had a high hydride concentration, and no degassed components. Example 5 had a low viscosity and good syringe consistency, but had a low tear strength and a high percent deformation and strain. This composition had a high hydride concentration, a low surfactant concentration, a low retarder concentration and a low catalyst concentration. The compositions of Examples 6, 8, and 9 did not polymerize properly. The composition of Example 6 had too low a retarder and catalyst concentration. The surfactant was too high in HLB and too acidic. The composition of Example 7 lacked the ability to wet and exhibited a surface contact angle exceeding the desired limit. In Examples 8 and 9, both the retarder and catalyst concentrations were too low. The composition of Example 10 exceeded the desired percent deformation.

Examples Using PEG-8 Methicone Surfactant In other respects, the impression material according to the present invention can be blended into various types of viscosities, etc., as usual. It is common in the dental industry to blend impression materials having a single phase, heavy, hard, low viscosity, very low viscosity and the like. A preferred impression material is effectively a two-component addition curable polyvinyl siloxane as described above. The material can also contain silanized, fumed, amorphous and / or crystalline silica, pigments, flavors, plasticizers and / or other surfactants. The material is used in a conventional manner as a dental impression material, taking advantage of the unexpected and improved properties described herein.

  Examples of useful impression materials to which the present invention can be applied include AQUASIL series impression materials to which a PEG-8 methicone surfactant such as BASF MASIL SF 19 surfactant is added (DENTSPLY International Inc., York, PA, USA). Is commercially available).

  The following are examples of compositions prepared according to the present invention.

  The following table shows the physical property values of the very low viscosity, low viscosity, single phase and hard forms of the present invention using MASIL SF-19. As can be seen from the table and FIG. 3, the wettability and tear strength are greatly improved over those obtained with the prior art. In the table, XLV is extremely low viscosity, LV is low viscosity, RS is usually cured, and the above terms are commonly used in the art.

6 is a graph showing wet contact angle (degrees) as a function of time (minutes). It is a graph which shows the viscosity of an impression material as a function of time (minute). 2 is a graph showing percent elongation and tear strength (psi).

Claims (4)

  A dental impression material comprising polyvinyl siloxane and a surfactant, wherein the surfactant has a surface contact angle with water of the impression material of less than about 50 degrees after about 3 minutes with respect to the composition. Dental impression material that imparts wettability.   The dental impression material according to claim 1, wherein the surfactant imparts wettability to the composition so that the surface contact angle of the impression material with water after about 30 seconds is less than about 10 degrees. .   The dental impression material according to claim 1, wherein the surfactant imparts wettability to the composition so that the surface contact angle of the impression material with water in about 30 seconds is about 2 degrees. The dental impression material according to claim 1, wherein the surfactant is PEG-8 methicone.

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