JP5449640B2 - Polyorganosiloxane dental impression material - Google Patents

Description

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

  The present invention is directed to the improvement of room temperature crosslinkable polyorganosiloxanes that have good dimensional stability when cured or hardened. More particularly, the present invention is directed to improving two-component type compositions. The first component includes an organopolysiloxane having a vinyl group capable of addition reaction with an organopolysiloxane having a hydrogen atom bonded to the silicone. The second component includes a catalyst that can promote the addition of hydrogen atoms bonded to silicone atoms to vinyl groups.

  One major field of use for these room temperature curable polyorganosiloxane compositions is dentistry. Such materials are typically used as impression materials to ensure similar models of oral hard and soft tissues to support subsequent work pieces such as crowns, bridges, dentures and other oral prostheses. The For dental applications, the fidelity of structure reproduction needs to be extraordinarily high in order to ensure good precision, such as conformity of the oral prosthesis. In this regard, dimensional changes of the impression material during curing should be avoided. Furthermore, there should be absolutely no irregularities, scratches, pits and other defects on the surface, such as replicas or oral prostheses. This is because good castings and prostheses from such impressions have good surface quality in order to have a proper fit, achieve good adhesion and avoid irritation to sensitive oral structures It is necessary to have pits and irregularities. Such polyorganosiloxanes are also useful in other fields where precision manufacturing is important, such as metrology, experimental processing for SEM, and even jewelry production.

  Several difficulties have arisen when using polyorganosiloxane as a dental impression material. First of all, the tear strength tends to be low. When actually taking an impression, it is necessary to be able to easily remove the impression from the teeth without tearing it in a particularly thin peripheral region in order to preserve fine details. Traditionally, various fillers have been added to improve tear strength. Such additions may result in some improvement of about 10%, but such improvements have been found to be insufficient.

Paradiso, in WO 93/17654, incorporates a polyfunctional polysiloxane component, including tetrafunctionality, into an impression material, and in the resulting cured impression material matrix, in particular linear with vinyl groups terminated. It describes improving the tear strength by increasing cross-linking along the length of the polysiloxane major component. The Paradiso composition comprises SiOH groups that are capped off with Me ₃ Si units that form groups depending from the molecule. These pendant groups only provide mechanical or physical linkage between the linear polysiloxane chains. This solution is insufficient because it has no chemical action and low crosslink density.

Voigt et al. In European Patent Application No. 0522341, using “QM” resin as a means of accelerating and increasing cross-linking results in a very short processing time of 35-45 seconds to form a dental occlusal stamp. It is described. These resins contain, as Q, tetrafunctional SiO _4/2 and M as monofunctional unit R ₃ SiO _1/2 (where R is vinyl, methyl, ethyl or phenyl), or similar trifunctionality Or a structural unit such as a bifunctional unit. Voigt describes the production of elastomers with less elastic deformation and higher toughness and hardness. However, such a material lacks flexibility, has a low strain value, and is not suitable for taking an impression. The processing time is very limited due to the increase in the crosslinking rate of the QM resin, which is not satisfactory.

  Another major known difficulty of polyorganosiloxane impression materials is caused by its inherent hydrophobicity. Because the oral environment is wet and often contaminated with saliva or blood, such characteristics make it difficult to replicate oral hard and soft tissues. The hydrophobic nature of the impression material can often result in a loss of surface detail on the critical surface of the teeth.

  Some of the improvements in polyorganosiloxane impression materials have focused on adding surfactant components to dental impression materials to weaken the hydrophobic nature of the polysiloxane and make the composition more hydrophilic. Yes. For example, Bryan et al., US Pat. No. 4,657,959, added a nonionic ethoxylated surfactant containing a group that solubilizes siloxane or perfluoroalkyl to give a water contact angle of about 3 minutes later. It describes that less than 65 ° was realized. Listed are surfactants containing hydrocarbyl groups to make the surfactants soluble or dispersible in the silicone prepolymer, including ethyleneoxy groups, but the results achieved are not optimal. Seem.

  In summary, polyorganosiloxane impression materials are torn to improve the use of these compositions for taking oral hard and soft tissue impressions so that proper operating time, tear strength and wettability are obtained. There is still a need for improved strength and wettability.

The novel polyvinylsiloxane impression material is useful as a high-viscosity and low-viscosity impression material for recording hard and soft tissues in the oral cavity. This novel impression material is a two-component vinyl polysiloxane material using platinum as a catalyst. This two-component polymerizable organosiloxane composition, wherein one component includes a polymerization catalyst for making a dental impression,
(A) a QM resin containing a vinyl group,
(B) a vinyl-terminated linear polydimethylsiloxane fluid to form a dispersion with a vinyl content of about 0.16-0.24 mmol / g with the QM resin;
(C) an organic hydrogen polysiloxane for crosslinking the vinyl group,
(D) an organoplatinum catalyst complex for accelerating the polymerization of the components,
(E) an emulsifying plasticizer for the catalyst complex,
(F) an amount of a retarder component sufficient to temporarily delay the initiation of the polymerization,
It consists of (g) a filler, and (h) a surfactant that imparts wettability to the composition, and the water contact angle of the composition after 3 minutes is less than 50 °.

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

  The viscosity of the dispersions (a) and (b) is preferably about 5,000-60,000 cps. The dispersions of (a) and (b) can include a plurality of dispersion components having a desired viscosity and QM resin content. The QM resin-containing dispersion includes 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. It preferably accounts for about 20-25% by weight.

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, aryl, etc.]. More preferably, the QM resin has structure 1.

  The retarder component of the composition is a low molecular weight fluid containing vinyl groups and is a linear or cyclic polysiloxane in an amount of at least about 0.030% by weight of the composition. The retarder component preferably comprises fluid 1,3-divinyldimethyldisiloxane in an amount of about 0.030 to 0.10% by weight of the composition.

  The composition includes an emulsifying plasticizer that imparts the desired operational and flow characteristics to the catalyst complex that are compatible with the characteristics of the second component, and conveniently forms a composition suitable for taking a dental impression. be able to. The plasticizer preferably contains about 0.5-2.0% by weight of the catalyst component alkyl phthalate, most preferably octylbenzyl 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 of the present invention is a surfactant, preferably having an HLB of about 8-11 and a pH of about 6-8, to impart wettability. The most preferred surfactant is the nonionic surfactant nonylphenoxy poly (ethyleneoxy) ethanol with an HLB of about 10.8.

  After polymerization, the composition of the present invention has a tear strength of 270 to 300 PSI (1.86 to 2.06 MPa) and a water contact angle of less than 50 ° after 3 minutes.

  According to another embodiment of the present invention, a base paste and a catalyst paste are prepared. The silicone glycol surfactant is then present in both pastes or only one paste. According to the present invention, a contact angle of less than 10 ° was realized in less than 15 seconds.

  Exemplary polymerizable polysiloxane compositions of the present invention generally comprise a tetrafunctional vinyl polysiloxane resin comprising an organopolysiloxane having at least about 2 vinyl groups per molecule and further dispersed therein; Organohydrogenpolysiloxanes having at least about 2 hydrogen atoms bonded to at least 2 silicone atoms per atom; including the emulsifying plasticizer, accelerates the addition of silicone atoms bonded to hydrogen atoms to the polysiloxane vinyl group 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 is referred to for convenience as a “base paste” and includes a vinylorganopolysiloxane dispersion, an organohydrogenpolysiloxane, a portion of a filler, and a surfactant. The second component of this two-component composition is called “catalyst paste”, which is a catalyst for promoting the addition reaction of the second part of vinyl polysiloxane, an emulsifying plasticizer, and hydrogen released during polymerization. And usually with additional amounts of fillers and pigments.

  A wide range of organopolysiloxanes having at least about 2 vinyl groups per molecule that can be included in the dental polysiloxane compositions of the present invention to form dispersions containing tetrafunctional vinyl polysiloxanes It has been known. Each of these materials is included to a greater or lesser extent in accordance with the practice of the present invention. Preferred for use in the present invention are linear polydivinylsiloxanes terminated with vinyl groups, preferably divinylpolydimethylsiloxane. Such polymers are commercially available with various average molecular weights and viscosities that vary accordingly. These materials are preferably selected to have a viscosity suitable for the conditions experienced by the resulting silicone material.

  Interesting dispersions have a viscosity range of 5,000-60,000 cps. In practice, it is advantageous to use a blend of dispersible polymers having different viscosities and physical properties to provide a composition having the desired thixotropy and viscosity.

  Interesting dispersions are preferably formed in two viscosity ranges. That is, (1) the first dispersion has a viscosity of about 5000 to 7000 cps, and (2) the second dispersion has a viscosity of about 45,000 to 65,000 cps. For this purpose, it is advantageous to provide polysiloxane oligomers having methyl substituents, but other substituents can also be included in the composition according to the invention. Thus, alkyl, aryl, halogen, and other substituents can be included to a greater or lesser extent as useful vinyl polysiloxane moieties. Those skilled in the art will be able to determine which polysiloxane material is preferred among the above considerations for a particular application.

Tetrafunctional polysiloxanes, known and known in the art as QM resins, improve the tear strength of the post-polymerization impression composition by increasing the post-polymerization crosslink density. As is known, QM resins are tetrafunctional SiO _4/2 units and M units such as R ¹ R ² ₂ SiO _1/2 [wherein R ¹ is unsaturated, preferably vinyl, R ² is alkyl such as methyl, ethyl and phenyl, aryl and the like]. In a preferred composition, R ¹ is vinyl and both R ² are methyl. The most preferred composition is that represented by Structure 2.

  The QM resin has a vinyl concentration in the dispersion containing the vinyl group-terminated polydivinylsiloxane of at least about 0.16 mmol / g. The vinyl concentration is preferably 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, USA. Commercially available. Other QM resin formulations can be used, including those “neat” or dispersed in a carrier other than the preferred fluid polydivinylsiloxane.

  The most important element of the present invention is a retarder component that delays the onset of polymerization of the QM resin / dispersion so as to provide sufficient operating time to use the composition. This serves to counteract what would otherwise be a premature polymerization when consumed. A preferred retarder fluid in interesting and preferred impression materials is 1,3 divinyldimethyldisiloxane in a concentration sufficient to perform a retarding function, which is at least about 0.03% by weight of the composition, preferably about 0. It is in the range of 03 to 0.10% by weight. This preferred amount is in contrast to the lesser amounts of 0.0015 to 0.020% by weight normally used in PVS systems to stabilize the composition. Other suitable retarders are any low molecular weight vinyl-based materials, including linear and cyclic polysiloxanes, which should be consumed first in the polymerization to retard hardening as appropriate and desired. It is.

  Organohydrogenpolysiloxanes useful in the practice of the present invention are well known to those skilled in the art. It is only necessary to use polysiloxanes in which hydrogen atoms are bonded directly to silicone atoms and that they have the appropriate viscosity and other physical properties. Substituents in the molecule such as alkyl (particularly methyl), aryl, and halogen can be used in the same manner. It is only necessary that such substituents do not interfere with the platinum-catalyzed addition reaction. It is preferred to use molecules having at least two hydrogen atoms bonded to the silicone per molecule. Polymethylhydrogensiloxane having a viscosity range of about 35 to 45 cps is preferred.

  Catalysts useful for catalyzing the reaction of silicone atoms (bonded to hydrogen atoms) with vinyl groups of vinyl polysiloxane molecules are preferably platinum-based. In this regard, it is preferred to use a platinum compound such as hexachloroplatinic acid, preferably an admixture or complex with one or more vinyl materials, in particular vinyl polysiloxanes. While such materials have been found to be preferred, other catalysts are also useful. Therefore, the combined use of platinum metal with other noble metals including palladium, rhodium, etc., and their respective complexes and salts are also useful. However, platinum is highly preferred for dental applications in view of its toxicological acceptability.

The composition according to the invention also comprises a mixture of fillers, preferably hydrophobic fillers. A wide range of hydrophobic inorganic fillers such as silica, alumina, magnesia, titania, inorganic salts, metal oxides and glass can be used. However, it is preferred to use various forms of silicone. According to the invention, derivatives thereof, ie crystalline silicone dioxide such as finely divided quartz (4-6μ); amorphous silicone dioxide such as diatomaceous earth (4-7μ); and Cab-o-Sil manufactured by Cabot Corporation. It has been found preferable to use a mixture of silicones, including silanated fumed silica such as TS-530 (160-240 m < ² > / g). Control the size and surface area of the above materials to control the viscosity and thixotropy of the resulting composition. As is known to those skilled in the art, some or all of the above hydrophobic fillers can be surface treated with one or more silanizing agents or “coupling” agents. Such silanization can be achieved by the use of known halogenated silanes or silazides. It is preferred that the filler be present in an amount of about 15 to about 45% by weight of the composition to form a polymer rich impression composition and thereby improve flow characteristics. More preferably, the filler is about 35-40% by weight of the composition. A preferred filler mixture comprises 14-24% by weight crystalline silicone dioxide, 3-6% by weight amorphous silicone dioxide, and 4-8% by weight silanized fumed silicone dioxide. The most preferred fillers are about 19% cristobalite with a particle size of about 4-6μ, about 4% diatomaceous earth with a particle size of about 4-7μ, and about 6% silanized fumed silica with about 160-240 m ² / g.

Chemical systems can be used to reduce the frequency or extent of hydrogen gas emissions that can normally occur as a result of vinyl polymerization. Thus, the composition can include finely divided platinum metal that captures and absorbs such hydrogen. A Pt metal having a surface area of about 0.1 to 40 m ² / g can be deposited on the substantially insoluble salt. Suitable salts are barium sulfate, barium carbonate and calcium carbonate of appropriate particle size. Other substrates include diatomaceous earth, activated alumina, activated carbon and the like. Inorganic salts are particularly preferred for imparting improved stability to materials obtained by incorporating them. About 0.2-2 ppm of platinum metal is dispersed on the surface of the salt, 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 the curing of dental silicone.

  An important improvement of the present invention is that PEG-8 imparts wettability to the composition as indicated by a surface contact angle with water of less than 50 ° after 3 minutes, more preferably less than about 10 ° after 30 seconds. The inclusion of a methicone surfactant in the composition. As an unexpected consequence of this choice of surfactant, a wet contact angle of less than 10 ° is about 30 in contrast to prior art polyvinyl siloxane and surfactant formulations that require longer times to wet. Realized in less than a second and reduced and maintained below 10 ° over the operation time of the composition provides clinically significant advantages. This higher wetting rate of the composition of the present invention is particularly advantageous during the impression taking process, which is shown in several figures.

  Referring to FIG. 1, for the polyvinylsiloxane composition of the present invention, the contact angle (in degrees) is shown as a function of time (in minutes) compared to prior art compositions. Curve A is the composition of the present invention and shows a wetting contact angle of about 50 ° 2 minutes after mixing the base component and the catalyst component. FIG. 1 demonstrates that good wettability is achieved early and increases at a fast rate over about 3.5 minutes, which is a useful pot life of the impression-taking material. Curves B and C are the polyether and the conventional polyvinylsiloxane impression material, respectively, of the prior art. FIG. 2 shows the impression material viscosity as a function of time for the composition of the present invention (curve A) and the two prior art compositions B and C described above. This shows the progress of the polymerization process after mixing and, in conjunction with FIG. 1, demonstrates that the improved wettability of the composition of the present invention occurs within the critical operating time of the impression material. This is an important advantage over other known systems.

  According to another embodiment of the present invention, the surfactant is only included in either the base paste or the catalyst paste. Preferably, it is put in the base paste. It is preferable to control the homogeneity of the mixture, such as by using several preselected stators in the mixer. Unexpectedly, it has been found that the stability and wettability of this formulation is improved. The problem of the presence of surfactant moisture and the problem of the catalyst causing decomposition of the platinum catalyst are avoided. Even more unexpectedly, as demonstrated below, the wettability of this material was greatly improved and a contact angle of 10 ° or better in 15 seconds or better was achieved.

  One of the surfactants of the present invention may be cationic, anionic, amphoteric or nonionic. An important criterion for selection is that the hydrophobic lipophilic balance (HLB) value (described in “Handbook of Industrial Surfactants” published by Gower, 1993) must be in the range of 8-11. . As is well known, the higher the HLB, the more hydrophobic the material. Further, the pH of the surfactant should be in the range of 6-8 to avoid side reactions that can adversely affect the polymerization of the impression. A preferred surfactant is a nonionic surfactant with a HLB value of 10.8, including nonylphenoxypoly (ethyleneoxy) ethanol, commercially available as Igepal CO-530 from Rhone-Poulenc, Cranbury, NJ, USA. For comparison, in connection with Bryan et al., U.S. Pat. No. 4,657,959, HLB13.0 Igepal CO-630, which has a different structure from CO-530, is ineffective and the limitation by HLB is critical. It has been pointed out above that it proves that there is. The number of repeating units is 9 for CO-630 and 6 for CO-530.

A preferred surfactant is PEG-8 methicone commercially available from BASF.
The compositions of the present invention can also include plasticizers that advantageously alter the operational and flow characteristics of the impression material, particularly the catalyst components. A preferred emulsifying plasticizer is octylbenzyl phthalate. Other phthalate esters are also useful.

  The compositions of the present invention can include various pigments to achieve a favorable coloration. Such pigments are well known and include titanium dioxide and many others.

  The two-component composition prepared according to the invention is used in the same way as a normal impression material. Accordingly, an appropriately equal amount of base paste and catalyst paste are thoroughly mixed together and applied to the oral teeth or other areas for a time sufficient to polymerize or harden the composition. When the composition is substantially hardened, it is removed from the oral cavity or other surface and used for crafting such as a casting, followed by preparation of a cast surface model.

  As will be appreciated by those skilled in the art, it is important that the dental silicone material can be stored for a fairly long period of time at a suitable storage temperature in order to maximize commercial utility. Accordingly, such materials are required to be free of degradation of physical properties or significant changes in operating time or hardening time during such storage. In this regard, the storability of such materials can now be determined by accelerated storage tests using high ambient temperatures.

  Several embodiments of the invention are described below. Numerous other compositions and formulations can be prepared within the spirit of the invention. The following examples should not be construed as limiting, but are provided as examples.

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 in a double planetary mixer in which a mixing pot is heated with circulating water at 45 ° C. to 50 ° C. under a vacuum of 65 mmHg.
Base paste component

  When preparing the base paste, first add all of the organohydrogenpolysiloxane to the mixing pot, then add the QM dispersion and filler components in small portions and mix until a uniform mixture is achieved. to continue. The completed substrate paste is delivered to a storage container.

Catalyst paste component The catalyst paste component is blended and mixed using the conditions and equipment described above. To the mixing pot, platinum catalyst, 1,3 divinyldimethyldisiloxane, QM resin dispersion, filler and pigment are added in portions and mixed until a uniformly mixed mass is achieved. Next, the mixed catalyst paste is delivered to a storage container.
The composition of each component is shown in the table below. In the table, the amounts are weight percent of the ingredients.

  As described in Example 1, a two-component composition of the present invention is prepared by first preparing a substrate paste having the composition shown in the following table, and then a catalyst paste.

  As described in Example 1, a two-component composition of the present invention is prepared by first preparing a substrate paste having the composition shown in the following table, and then a catalyst paste.

  As described in Example 1, a two-component composition of the present invention is prepared by first preparing a substrate paste having the composition shown in the following table, and then a catalyst paste.

  As described in Example 1, a two-component composition of the present invention is prepared by first preparing a substrate paste having the composition shown in the following table, and then a catalyst paste.

  As described in Example 1, a two-component composition of the present invention is prepared by first preparing a substrate paste having the composition shown in the following table, and then a catalyst paste.

  As described in Example 1, a two-component composition of the present invention is prepared by first preparing a substrate paste having the composition shown in the following table, and then a catalyst paste.

  As described in Example 1, a two-component composition of the present invention is prepared by first preparing a substrate paste having the composition shown in the following table, and then a catalyst paste.

  As described in Example 1, a two-component composition of the present invention is prepared by first preparing a substrate paste having the composition shown in the following table, and then a catalyst paste.

  As described in Example 1, a two-component composition of the present invention is prepared by first preparing a substrate paste having the composition shown in the following table, and then a catalyst paste.

  Equal amounts of 10 grams of the representative sample of each example described above are mixed and the properties of the mixture and the resulting composition after polymerization are tested. The measurement results are reported in the table below. The first five properties reported are tested according to ADA standard 19: non-water elastomeric impression material (1976, amended at 19a in 1982).

The following procedure was used to obtain the tensile tear strength, elongation, and modulus of the examples.
An equal amount of the base material component and the catalyst component are mixed, and a 1.5 mm thick, 20 mm × ll mm covered product having an I-shaped hole with a horizontal bar portion depth of 8 mm and a middle vertical bar portion width of 5 mm. This sample, that is, the specimen is placed in the specimen mold. The filled mold is fixed between two stainless steel plates and the assembly is placed in a 32 ° C. water bath. Six minutes after the start of mixing, the assembly is removed from the bath. Remove the mold from fixation, remove the specimen from the mold, and remove any burrs from the specimen. Ten minutes after the start of mixing, the subject is fixed in the subject test grip of an Instron Model 1123 in the extension mode. The Instron is attached to a Micron II micropressor programmed to calculate tear strength [psi], elongation and modulus. After 11 minutes, stress is applied to the subject through this Instron at a speed of 10 mm / min until the subject reaches peak failure (the maximum load is set to 5 kg). This is repeated for 5 subjects, and then the results of statistical evaluation are reported in the table.

  For each example, the wetting contact angle is measured as follows. 1 gram (1 g) of substrate and 1 gram (1 g) of catalyst paste are mixed together until uniform (about 30 seconds). 0.5 grams (0.5 g) of the mixed paste is placed between two pieces of polyethylene (Dentsilk) and pressed using a glass plate having a thickness of about 2 to 3 mm. The specimen is allowed to stand until it cures (about 15 minutes). The polyethylene sheet is removed with care so as not to touch the surface of the subject, and the subject is placed on a table of a ginometer well known as a contact angle measuring device. The eyepiece reticle is adjusted to the horizontal and vertical surfaces of the subject surface, and a stopwatch is started when a water droplet drops on the subject surface. After 1.5-3.5 minutes, using a dynamometer scale, measure the contact angle inside the water / analyte interface in degrees and record the analyte and report it below To do.

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

The composition of Example 4 has a higher hydride concentration, does not contain degassing components and is highly viscous, but outgassing is severe. Example 5 had low viscosity and good syringe consistency, but had high deformation rate (%) and strain rate (%) and lower tear strength. The hydride concentration of this composition was high, and the surfactant concentration, retarder concentration and catalyst concentration were low. The compositions of Examples 6, 8, and 9 did not polymerize properly. The composition of Example 6 was too low in retarder and catalyst. Further, the surfactant was too high in HLB and too acidic. The composition of Example 7 lacked the wetting ability and the surface contact angle exceeded the desirable limit. In both Examples 8 and 9, the concentrations of retarder and catalyst were too low. The composition of Example 10 exceeded the desired deformation rate (%).

Example using PEG-8 methicone surfactant As usual, except that PEG-8 methicone surfactant is used, the impression material according to the present invention can be formulated so as to have some properties such as viscosity. it can. In the dental industry, it is common to formulate impression materials such as single phase, heavy, hard, low viscosity, ultra low viscosity. The preferred impression material is actually a two-component addition-type curable polyvinylsiloxane as described above. The material can also include amorphous and / or crystalline silanized fumed silica, pigments, fragrances, plasticizers and / or other surfactants. This material can be used as usual for dental impression materials, taking advantage of its unexpectedly improved properties described herein.

Examples of useful impression materials that can be used with the present invention include the addition of PEG-8 methicone surfactants such as BASF's MASIL SF 19 surfactant to the commercially available impression materials AQUASIL series from Dentsply International, York, PA, USA. There is something.
The following are examples of compositions prepared in accordance with the present invention.

下記の表は、ＭＡＳＩＬ ＳＦ １９を使用した超低粘度、低粘度、単一相および硬質の形の本発明の物理的特性を示している。表および図３からわかるように、ぬれ性および引裂き強度が、当技術分野でこれまでに成し遂げられてきた以上に大幅に改善されている。表において、ＸＬＶは超低粘度であり、ＬＶは低粘度であり、ＲＳは通常硬化である。かかる用語は当技術分野で通常使用されているとおりである。

The table below shows the physical properties of the present invention in ultra low viscosity, low viscosity, single phase and rigid form using MASIL SF 19. As can be seen from the table and FIG. 3, the wettability and tear strength are greatly improved over that previously achieved in the art. In the table, XLV is very low viscosity, LV is low viscosity, and RS is normally cured. Such terms are as commonly used in the art.

界面活性剤全部を触媒ペーストと混ぜ合わせる前に基材ペーストに組み込む本発明の実施形態も下記に示されている。予想外なことに、本発明による界面活性剤を基材ペーストに組み込む場合のみ、接触角が改善されることがわかった。これらの接触角は、界面活性剤を基材ペーストと触媒ペーストの両方に組み込んだ本発明のものも、それ自体が従来技術に比べて改善が見られるが、それよりもかなり優れている。これは、界面活性剤を基材ペーストにしか含まない印象材料を示している従来技術からは予想できないことであった。このような材料がたとえ存在していても、どれもこの（本発明の）界面活性剤の改善を示しておらず、界面活性剤を両方のペーストに組み込む場合に比べて接触角データの一層の改善を開示していない。

An embodiment of the present invention that incorporates all of the surfactant into the substrate paste prior to combining with the catalyst paste is also shown below. Unexpectedly, it has been found that the contact angle is improved only when the surfactant according to the invention is incorporated into the base paste. These contact angles are considerably better than those of the present invention in which the surfactant is incorporated in both the base paste and the catalyst paste, although the improvements themselves are seen as compared with the prior art. This was unpredictable from the prior art showing impression materials that contain only surfactant in the base paste. Even if such a material is present, none show this (inventive) surfactant improvement, and more contact angle data compared to incorporating the surfactant into both pastes. Does not disclose improvements.

  For illustrative purposes, several materials according to this embodiment of the invention were prepared. These include examples of ultra low viscosity (XLV), low viscosity (LV), single phase, heavy viscosity and hard. Such terms are as commonly used in the dental art. RS is “normally cured”. Such terms are as commonly used in the dental art.

  The contact angle data is collected every other second from 15 seconds after mixing the base paste and the catalyst paste. For comparison, the same contact angle data was determined for several commercially available impression materials. This includes AQUASIL XLV, LV, rigid and single phase impression materials, commercially available from LD Cowk Division of Dentsply International. For the present invention and commercial products, contact angle data is shown in graphical form in FIG.

  As shown in FIG. 4, the contact angle after 1 second of this XLV, LV, hard, single phase and heavy blend is less than 80 °, whereas the contact angle of the AQUASIL material is over 100 °. Or even less than 20 °. After 15 seconds, the contact angles of the materials of the present invention were all less than 10 °, whereas the contact angles of the commercial products exceeded 60 °.

For the material of the present invention, a similar set of data was determined and graphed with the data for the impre gum impression material commercially available from ESPE. All of the contact angles after 2 seconds of the impreg gum material exceeded 50 ° and there was no or little improvement when extended to 15 seconds. The material of the present invention had a contact angle of 10 or nearly 10 after 2 seconds and exceeded 10 ° after 15 seconds. This data is reported in FIG.
Test data was obtained as follows.

Tear strength According to the manufacturing instructions, the materials are mixed and placed in a mold to prepare a specimen (see attached figure) for measuring tear strength in tensile mode. Ten specimens are prepared for each material.
2. When prepared for testing, cure all specimens for 15 minutes in an oven at 37 degrees before removing them from the mold.
3. With an Instron general purpose testing machine, pull all specimens in tensile mode within 1 hour. The subject is pulled at a speed of 100 mm / min until the subject having a right angle inside the subject is torn.
4). The force required to tear the subject is calculated using Instron's IX series software. Report the average of each trial.

Contact angle Mix materials according to manufacturing instructions.
2. The material is subdivided and placed in a 5 × 10 mm specimen ring between two Mylar sheets and pressed using a glass plate.
3. The specimen is allowed to stand for 15 minutes to cure.
4). Remove the Mylar sheet and remove the specimen from the ring, being careful not to touch the test surface of the specimen.
5. This subject is transferred to the test platform of the VCA 2500xe video contact angle instrument.
6). The instrument is set up so that the contact angle of the drop is measured in static mode for 35 seconds at 1 second intervals after first contact with water.
7.1 Obtain and record the contact angle after 1 to 30 seconds and graph.

Increase in viscosity Viscosity increase data was collected using a TA Instruments AR-1000 rheometer equipped with a temperature-controlled Peltier plate and a 4 cm, 2 ° conical structure.
2. The instrument was set up to collect viscosity data in shear mode using software and navigator scripts. A shear stress of 1000 Pa was used. The temperature was increased from 28 to 35 ° C. to simulate mixing and insertion into the oral environment.
3. The test material was mixed and immediately placed on the surface of the test bench directly under the 4 cm, 2 ° conical structure. The test script was started, the gap with the conical structure was 54 microns, a 1500 Pa pre-shear was performed for 5 seconds, and then viscosity data was collected at 1000 Pa for 5 minutes while the temperature was increased from 28 to 35 ° C.
4). Viscosity change over time was analyzed and transferred to Excel for graphical display.

  Other properties were tested according to standardized procedures such as ISO 4823 for elastomeric impression materials. It has also been observed that the tear strength data for the material of the present invention is as good as or improved compared to prior art materials. Further, in the case of the embodiment of the present invention in which the surfactant is incorporated only in the base paste, the improvement of the product stability was remarkable. All such improvements were obtained with a greatly improved contact angle.

  From these results, the material of the present invention has excellent characteristics, and is superior to commercially available impression material products particularly in terms of hydrophilicity and tear strength.

It is a graph which shows a wetting contact angle (degree) as a function of time (minute). Fig. 6 is a graph showing impression material viscosity as a function of time (minutes). It is a graph which shows elongation rate (%) and tear strength (psi). It is a graph which shows the wet contact angle (degree) as a function of time (second). It is a graph which shows the wet contact angle (degree) as a function of time (second).

Claims (1)

A dental impression material containing polyvinylsiloxane and PEG-8 methicone ,
2 the PEG-8 methicone is imparted wettability such as the surface contact angle is less than 10 ° with water after 15 seconds the dental impression material, and the PEG-8 methicone is the dental impression material A dental impression material which imparts wettability such that the surface contact angle with water after 10 seconds is 10 ° or less than 10 °.

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