JP2872485B2 - Dental wax composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dental wax composition used for making a wax mold for precision dental casting. In particular, the dental wax composition of the present invention is for producing a wax mold that reproduces as accurately as possible for casting tooth-deficient inlays or crowns.

[0002]

2. Description of the Related Art Conventionally, various waxes, natural resins and petroleum resins of animal and plant type, mineral type, petroleum type and synthetic type have been used as wax type materials in dental precision casting. That is, paraffin wax is used as a main component, and beeswax and microcrystalline wax are used to impart flexibility and tackiness. Dummar, rosin and petroleum resin are added to improve hardness and strength, to give toughness, and to provide a high melting point carnauba wax. In addition, dental waxes, especially dental casting waxes, have been produced by imparting gloss to the surface of the wax. No matter how the wax mold is made, it must accurately reproduce the tooth defect. Since the wax mold is the contour of the mold from which the metal is cast, no matter how carefully the other operations are performed, the casting can never be more accurate than the wax mold. Therefore, it is necessary that the wax mold be well fitted to the cavity, properly sculpted and deformed as little as possible.

[0003] After the wax mold is removed from the cavity, it is immersed in an investment material containing gypsum. After the investment material has hardened, it is heated to about 700 ° C. to completely incinerate the wax. Since such a wax composition uses a natural resin such as a dammer and rosin, it has no durability and a decrease in compatibility with the wax, which is disadvantageous as a wax for dental casting. Furthermore, beeswax and microcrystalline wax are added to give flexibility and ease of use, but wax formation, engraving during engraving,
It becomes easy to adhere and becomes difficult to use. Also, animal and plant waxes such as beeswax and carnauba wax are expensive. Further, at present, the shrinkage of the wax is large.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to remedy the above-mentioned disadvantages of the conventional dental casting wax. The present invention is a synthetic resin having excellent compatibility with wax instead of a natural resin.By using a hydrocarbon resin in combination with an ethylene-vinyl acetate copolymer resin, it is easy to prepare a wax mold, and extremely. A stable dental casting wax was obtained. Conventionally, the use of rosin-based resin, beeswax or microcrystalline wax has caused stickiness during wax engraving, but in the present invention, these rosin-based resins, beeswax and microcrystalline wax are removed. By blending the ethylene / vinyl acetate copolymer resin preferably in an amount of 1 to 5% by weight, the wax was given appropriate flexibility and could be modified.

Further, a paraffin wax and a synthetic wax are combined to form an effective blending amount of a hydrocarbon resin of 10 to 4 times.
By blending 0% by weight and 1 to 5% by weight of an ethylene / vinyl acetate copolymer resin, a wax for dental casting having relatively small shrinkage was obtained. That is, the present invention provides a softening point of a hydrocarbon resin having a softening point of 80 to 140 ° C. by 10 to 40% by weight, an ethylene / vinyl acetate copolymer resin by 1 to 5% by weight,
40-80% by weight of paraffin wax, synthetic wax 1
Thus, a preferred dental wax composition characterized by containing 含有 15% by weight was able to be produced.
As described above, the characteristic of the dental wax composition according to the present invention is that a hydrocarbon resin as a synthetic resin is combined with an ethylene / vinyl acetate copolymer resin, and a paraffin wax and a synthetic wax having a high melting point are blended in a specific ratio. The point is that the used wax is used.

In the present invention, natural resins and animal and plant waxes conventionally used for dental waxes are not used. Here, when the components of the dental wax are more specifically exemplified,
The hydrocarbon resin is composed of an alicyclic saturated hydrocarbon resin having a softening point (ring and ball method) of 80 to 140 ° C., an aliphatic hydrocarbon resin, and an aliphatic / aromatic copolymer resin.
It is preferable to combine with an ethylene / vinyl acetate copolymer resin having a temperature of 0 ° C. or lower in view of the flexibility, strength, and ease of dissolution of the dental wax. Paraffin wax has a melting point of 120
A wax having a temperature of ~ 150 ° F is suitable for use, and Fischer-Tropsch wax, hydrogenated castor oil, hydroxystearic acid and low molecular weight polyethylene are used instead of carnauba wax as synthetic waxes.

[0007] Hydrocarbon resins have good compatibility with wax, are light and heat resistant, and are stable substances. If the softening point is less than 80 ° C., there is a risk of deformation as a dental wax, and if it is more than 140 ° C., the softening / dissolving operation becomes difficult, which is not appropriate. If the content of this resin is less than 10% by weight, the hardness and strength are not sufficiently exhibited, and if it exceeds 40% by weight, the properties as a wax are lost, the engraving property is lost, and it becomes difficult to prepare a wax mold. Not so. Therefore, the hydrocarbon resin having a softening point of 80 to 140 ° C. used in the dental wax composition of the present invention is 10 to 40% by weight.
Is preferred.

Ethylene-vinyl acetate copolymer resins having a softening point (ring and ball method) in the range of 80 ° C. to 120 ° C. are suitable because they have good solubility in wax and do not have a large risk of deformation. Content of vinyl copolymer resin is 1
If it is less than 5% by weight, the toughness is not exhibited, and if it exceeds 5% by weight, the tendency of deformation is large, which is not preferable. Therefore, the softening point (ring and ball method) used for the dental wax composition of the present invention is 80 to 80.
The amount of the ethylene / vinyl acetate copolymer resin at 120 ° C. is preferably 1 to 5% by weight. Paraffin wax has a melting point of 120
~ 150 ° F is used. If the paraffin wax is less than 40% by weight, the softening and dissolving is not smooth,
The feeling of the wax is lost, the sculpability deteriorates, and it becomes difficult to prepare a wax mold. On the other hand, if it exceeds 80% by weight, the brittle nature of paraffin wax becomes strong, and the engraving property is extremely lowered, which is not suitable. Therefore, the content of paraffin wax is preferably 40 to 80% by weight.

The synthetic wax has a softening point (ring and ball method) of 90 to 90.
Those at 120 ° C. impart hardness to the wax, and the melting operation is moderate. If the synthetic wax is less than 1% by weight, the effect of hardness is not recognized. On the other hand, if it exceeds 15% by weight, the wax is hardened rapidly and the operation allowance time becomes extremely short, so that it is not appropriate. Therefore, the synthetic wax used in the present invention is 1 to 15
% By weight is preferred. The composition of the present invention has been described in detail above. The effects will be described with reference to examples, but the present invention is not limited to these examples.

[0010]

EXAMPLES Example 1 (% by weight) Alicyclic hydrocarbon resin (softening point 135 ° C) 20 Aliphatic / aromatic hydrocarbon resin (softening point 95 ° C) 10 Ethylene / vinyl acetate copolymer resin (softening point 100 ° C) 4 130 ° F paraffin wax 64 Low molecular weight polyethylene (trade name: Sunwax 131-P, manufactured by Arakawa Chemical Co., Ltd.) 1 Fischer Tropsch wax (coagulation point 95 ° C) 1

The above-mentioned six components were weighed and put into an electric melting pot, heated and stirred at a temperature set at 130 ° C. for 20 minutes, and completely dissolved. Immediately after filtration, the sample was stored in a rod shape, a plate shape, or a can to obtain a sample. The test results are as shown in Table 1. In particular, the penetration was smaller than that of the comparative example, indicating a hard property, and the coefficient of thermal expansion was reduced by about 20%. The abrasion feeling of the wax was good without stickiness.

Example 2 (% by weight) Alicyclic hydrocarbon resin (softening point 90 ° C.) 8 Aliphatic hydrocarbon resin (softening point 100 ° C.) 7 Ethylene / vinyl acetate copolymer resin (softening point 85 ° C.) 2 140 ° F paraffin wax 52 125 ° F paraffin wax 26 Fischer-Tropsch wax (freezing point 95 ° C) 5

The above-mentioned six components were weighed and put into an electric melting vessel, heated and stirred at a temperature set at 110 ° C. for 20 minutes, and completely dissolved. The sample was immediately filtered, stored in a rod shape, a plate shape, or a can to obtain a sample. The results of the test are as shown in Table 1. The penetration was smaller than that of the comparative example, indicating a hard property, and the coefficient of thermal expansion was reduced by about 25%. The abrasion feeling of the wax was good without stickiness.

Example 3 (wt%) Alicyclic hydrocarbon resin (softening point 115 ° C) 38 Ethylene / vinyl acetate copolymer resin (softening point 120 ° C) 3 145 ° F paraffin wax 15 130 ° F paraffin wax 30 Curing Castor oil 8 Hydroxystearic acid 6

The above-mentioned six components were weighed and put into an electric melting pot, heated and stirred at a temperature set at 120 ° C. for 20 minutes, and completely dissolved. The sample was immediately filtered, stored in a rod shape, a plate shape, or a can to obtain a sample. The results of the test are as shown in Table 1, showing that the penetration was small and hard compared to the comparative example, and the coefficient of thermal expansion was reduced by about 40%. The abrasion feeling of the wax was good without stickiness.

Comparative Example 1 (% by weight) Dammer 13 130 ° F. paraffin wax 45 140 ° F. paraffin wax 30 carnauba wax 10 beeswax 2

The above five components were weighed and put into an electric melting vessel, and heated and stirred at a temperature set at 110 ° C. for 20 minutes to completely dissolve. The sample was immediately filtered, stored in a rod shape, a plate shape, or a can to obtain a sample. The test results are as shown in Table 1. The freezing point is 57.4 ° C. and the penetration is 0.8.
It was 0 (mm), which was within the range of ordinary dental wax, and the coefficient of thermal expansion was 0.45%. This wax had a sticky feeling during engraving, but could form a wax pattern. When left at room temperature for 6 months and then heated and melted to form a swell, it was not completely dissolved and some residues were observed.

[0018]

[Table 1]

Thermal expansion coefficient: According to the method of JIS T-6503. Penetration: A sample molded to a diameter of 10 mm and a height of 6 mm was subjected to a load of 3 under constant temperature and humidity (23 ± 1 ° C., 50 ± 1%).
00g was added for 5 seconds using a 1.0 mm diameter Vickers needle, and the depth was measured. The smaller the value, the greater the hardness. Engravability: The degree of shaving of the wax was examined using a wax instrument. Heat solubility: 1 g of the sample was left at 110 ° C. for 5 minutes, and the presence or absence of a dissolved residue was examined.

[0020]

As is clear from the test results in Table 1, the dental wax composition of the present invention is particularly stable as an inlay wax for casting without any residue when melted by heating, and has a stickiness. Because of this, the engravability was smooth, the expansion and shrinkage were small, the penetration was small, and the hardness was large. Therefore, the dental wax composition with little deformation was successfully produced for the first time.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) A61K 6/00 A61C 13/20

Claims (4)

(57) [Claims] 1. A hydrocarbon resin containing 40 to 80% by weight of paraffin wax and 1 to 15% by weight of synthetic wax.
% By weight and 1 to 5% by weight of ethylene / vinyl acetate copolymer resin
A dental wax composition comprising a combination of: 2. The dental product according to claim 1, wherein the synthetic wax is at least one selected from the group consisting of Fischer-Tropschwax, hydrogenated castor oil, hydroxystearic acid and low molecular weight polyethylene. Wax composition. 3. The dental wax composition according to claim 1, wherein the hydrocarbon resin has a softening point of 80 to 140 ° C. 4. The dental wax composition according to claim 1, wherein the ethylene / vinyl acetate copolymer resin has a softening point of 80 to 120 ° C.