JPH01268613A - Dental impression material - Google Patents

Abstract

PURPOSE:To obtain a dental impression material, consisting of ethylene-vinyl acetate copolymer and an oil and having characteristics of being readily flowable at a temperature for collecting an impression, sufficiently retaining the shape below about the bodily temperature and fixing as an elastomer. CONSTITUTION:A dental impression material consisting of 20-80wt.% ethylene- vinyl acetate copolymer (EVA resin) and 80-20wt.% oil (e.g., cotton seed oil, coconut oil, whale oil, beef tallow oil, mineral oil or synthetic oil), and, as necessary, an additive (e.g., waxes or inorganic and organic filler). The vinyl acetate content of the EVA resin is preferably 20-50wt.%. The above-mentioned impression material is inexpensive with affinity for mucosal surfaces of the oral cavity and gypsum and can be readily used simply by, e.g., extrusion from a tube, without requiring skilled techniques. The accuracy in the reproducibility of tissue details in the oral cavity is high and sharp without any influence of exudates in the oral cavity. Furthermore, a change with time is not caused, since water is not contained.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to impression materials used in dentistry.

[Prior art] Conventionally, dental impression materials include gypsum impression material, which is a non-elastic impression material, zinc oxide Nishinol impression material, modeling compound, and agar impression material, which is an elastic impression material, alginate impression material, polysulfide rubber impression material, and silicone rubber. Impression materials and polyether rubber impression materials are known. Among these, hydrophilic agar impression materials and sodium alginate, and hydrophobic silicone rubber impression materials are mainly used. The agar impression material and the silicone rubber impression material are suitable for taking impressions with undercuts, and the agar impression material has the advantage of being inexpensive and having an affinity for the oral mucosal surface. Silicone rubber impression materials have the advantage of high precision and sharpness in the reproducibility of delicate parts of the oral cavity, as well as being unaffected by intraoral exudates.

[Problems to be Solved by the Invention] Although the above-mentioned hydrophilic impression materials have the above-mentioned advantages, they suffer from the problems of causing syneresis, low precision, lack of sharpness, and causing errors in impression dimensions due to intraoral exudates. Furthermore, silicone rubber impression materials have the problems of being expensive and lacking in affinity for the oral mucosal surface.

Therefore, it is an object of the present invention to provide an impression material that is suitable for taking impressions with undercuts, has good affinity for oral mucosal surfaces, and has the advantages of silicone rubber impression materials.

[Means for Solving the Problems] The present invention is based on an ethylene-1 vinyl acetate copolymer (hereinafter referred to as E
This was developed by focusing on the properties of VA resin.

E V A fθ1 fat alone still has a high softening temperature, and even at a slightly high temperature it remains sticky and sticky.

9 As a result of intensive research, the present inventor found that by uniformly mixing an appropriate amount of oil with EVA resin, it flows easily at about 60°C at the time of impression taking, and is stable at body temperature. We have discovered and completed a composition that is effective as an impression material and has the property of sufficiently retaining its shape and solidifying as an elastic body.

The composition obtained according to the present invention is an impression material that does not adhere to oral tissues, has excellent reproducibility, can form impressions including undercuts, and does not change in size over time at room temperature.

That is, the present invention provides ethylene-vinyl acetate copolymer 20
It is an impression material consisting of ~80% by weight and 80-20% by weight of oil.

If necessary, additives may be added to these.

The EVAvA fat has the following repeating structural formulas [A] and [B]
A copolymer having a specific vinyl acetate content may be used, or a combination of EVA resins having different vinyl acetate contents may be used.

The vinyl acetate content is preferably 20 to 50 wt.

1+CI, -CH,-+-(A) →C1l, -C1l→-(t3) IL The oil is vegetable oil such as cottonseed oil, peanut oil, olive oil, orange oil, corn liver oil, castor oil, sesame oil, coconut oil, etc. Oils and fats of animal origin, such as whale oil, beef tallow, pork fat, and more.

Mineral oils, synthetic oils, etc. are preferred.

The additives include waxes such as paraffin, inorganic fillers such as calcium carbonate, talc, lylastonite, silicon dioxide, titanium oxide, diatoms, calcium silicate, crow, glass peas, and crow balloons, and Preferred are plastic snack powders, such as polyethylene powder, styrene beads, acrylic beads, organic fillers such as vinyl octate resin, and the like.

Of course, in addition to these, coloring with pigment dyes and the like, addition of flavoring and sweetening, etc. can be carried out as appropriate.

[Examples] Examples are shown below to more specifically explain the present invention, but the present invention is not limited to these examples as long as the gist of the present invention is not exceeded.

Examples 1 to 6 are shown in Table 1. In Table 1, E V
A resin (A> has a vinyl acid content of 28 wt%, a melt flow rate of 2 Of/10 nin, and an EVA resin <8
> has a vinyl acetate content of 28wt%, a melt flow rate of 7g/10n+in, and an EVAI! A fat (C)
EVA resin (D) has a vinyl acetate content of 25 wt% and a melt flow rate of 3.
g/10Ilin, EVA resin ('E) has a vinyl acetate content of 41 wt%, and a melt flow rate of 1.60+
r/10m1n.

The components of Examples 1 to 5 are each mixed uniformly at 150°C to form an impression material, which is then filled into, for example, a tube-shaped container and stored at 60°C.

When used, it is squeezed out of the tube, placed on a tray, and placed in the oral cavity, where it solidifies in 2 to 3 minutes. Gypsum is injected into this and a mold is formed.

Example 1 is an ultra-high viscosity impression material, Example 2 is a high viscosity impression material, Example 3 is a medium viscosity impression material, Example 4 is a low viscosity impression material, and Example 5 is an inorganic filler. This is an example of the formulation of an added low-viscosity impression material.

The impressions obtained in these Examples were thermoplastic, reversible, elastic, and hydrophobic, and had good dimensional accuracy and excellent reproducibility of oral mucosa.

Example 6 is a silk composition for multiple impressions, and as in Examples 1 to 5, it is mixed uniformly at 150'C and used as an impression material when molding a multiple model.

For example, heat this in a container to 60-80°C and set it in a link. Pour it on top, let it cool and solidify, and then inject plaster into it to create a duplicate model. Example 1~
・In addition to having 5 advantages, it also had the feature of being able to be used repeatedly.

Table 1 [Effects of the Invention] The present invention has the following effects. In other words, conventional impression materials that require heating of two liquids or mixing of powder and liquid during use can cause variations in curing time and dimensional accuracy if the mixing ratio is inaccurate or kneading is insufficient. Although it was difficult to handle,
The impression material of the present invention can be easily used by simply extruding it from a tube, for example, and does not require skilled techniques. It is also relatively inexpensive and has an affinity for oral mucosal surfaces and plaster. In addition, the intraoral set 1N has high accuracy and sharpness in reproducing details, is not affected by intraoral exudate, does not contain water, does not change over time, and is reusable. Furthermore, the odor, heat, etc. do not cause pain to the patient, and by using orange oil, pepper oil, and perfume, it is possible to give good or bad effects to the patient. Furthermore, since it is possible to bond the impression material to the impression material, even if the first impression fails, it is possible to add an impression material thereon and make another impression.

In addition, in the case of an impression such as the edges, it is possible to add more, and only the edges can be heated with warm water to obtain an R-type impression. It can also be used as a tissue conditioner and elastic lining agent.

The present invention is made by adding oil to an ethylene-vinyl acetate copolymer, and can provide an impression material that has both the advantages of an agar impression material and a silicone rubber impression material.

Patent applicant: Shinsei, Dental, Laboratory, Ltd.

Claims (1)

[Claims] 20-80% by weight of ethylene-vinyl acetate copolymer and 8% oil
A dental impression material comprising 0 to 20% by weight.