USRE23700E - Dental impression composition - Google Patents

Description

Reissues! Aug. 18, 1953 sum pmsr. mrrmssr'on ooMrosrrroN Edwin II. Lochridge, Glendale, alif., assignor to Dental Perfection Company, a

California company of No Drawing. Original No. 2,568,752, dated September 25, 1951, SeriaLNo. 764,247, July 28, 1947. Application for reissue January 21, 1953,

Serial No. 332,581

zs Claims. (oi. 1 7) Matter enclosed in heavy brackets I: appears in the original patent but forms no part of this relaauo specification; matter printed in italics indicates the additions made by reissue.

1 This invention relates to a new dental impression compound and the method of producing the same.

For many dental purposes such as making of full dentures, partial dentures, bridges, etc., it is necessary for the dentist to be able to accurately reproduce portions of the mouth of the subject. Such reproductions often involve the duplication of undercuts of more or less severity, as for instance in the case where a tooth or teeth have been extracted and the adjacent teeth have crowded together.

l'br many years dental impressions have been taken with materials such as plaster of Paris, or various shellac or wax compositions. These materials have little or no elasticity and while it is not difficult .to take some impressions with them, such as for most full dentures, it is not possible to reproduce accurately undercuts without either breaking the impression and re-assembling it, as is done with plaster, or taking the impression in sections, as is the practice in the use of shellac and wax compounds. The foregoing methods obviously involve time and there is the danger-of inaccuracy, as well as discomfort to the patient.

My dental impression material is composed of a suitable gel forming agent, such as sodium, potassium or ammonium alginate, sodium methylcarboxycellulose or sodium, potassium or amnionium pectate. Mixtures of the foregoing gel forming agents may be used in my new composition.

To the above gel forming agent there is added lead monosilicate. I have found that lead monosilicate is especially desirable in my composition since it eliminates the necessity of a setting agent, such as calcium sulphate. All forms of lead silicate do not give satisfactory results in my composition. For example, I have found that lead bisilicate will not produce a satisfactory impression material when used in my composition. The difference in behavior of lead monosillcate and lead bisilicate will be apparent by reference to the examples in the specification.

. To the above composition I also add a fluosilicate. Most fluosilicates appear to give satisfactory results, however, I prefer to use sodium fluosilicate, aluminum iluos'ilicate and ammonium fluosilicate.

To the foregoing compounds I also add a filler, such as diatomaceous earth in a finely ground form. Other fillers, such as fullers earth or talc may also be used.

I also add an alkali metal carbonate, such as sodium or potassium carbonate. Or in place of the carbonate I may add a water soluble phosphate.- Many phosphates work satisfactorily, for example, I may use trisodium phosphate, sodium metaphosphate, potassium diphosphate, primary sodium phosphateor sodium acid pyrophosphate, however, I find that tetrasodium pyrophos'phate works especially well. In using any of the foregoing phosphates or carbonates in my composition caution must be exercised in the amount employed since the final composition is very sensitive to a change in the amount of these ingredients employed. The use of either too much phosphate or carbonate tends to retard or inhibit the set in the final composition.

To the foregoing I add sumcient water to form a stiff paste when spatulated (mixed) and then place this paste into the dental tray for taking the impression.

It is, therefore, an object of the present invention to produce a composition of matter suitable methyl carboxycellulose, an alkali metal carbonate or a phosphate and water.

The following compositions are modifications ofthe impression material made according to my invention. These composition were blended by rollingin a small :Iar mill:

Example I Grams Material Diatomaoeous earth. Exfoliated Peal-lite (210 mesh). Lead monosllicate.

Potauium alginate. Tetrasodium pyrophosphate. Sodium fluosiiicate.

sta es Sixteen grams of the foregoing blended com- .position were thoroughly mixed with 25 cubic centimeters of water (70 F.) in a rubber mixing vessel with a spatula, after which the contents of the mixing vessel were transferred to the sur- Sixteen grams of the foregoing composition were mixed, as in Example I, with 25 cubic centimeters of water (at 70 F.) and placed on a glazed tile. After 3 minutes the mixturegplaced on the tile had become firmly set.

Example In eassjs Thirty-two grams of the above blend were mixed with 50 cubic centimeters of water (at 70 F.) and the mixture was transferred to a glazed tile. After 2% minutes this mixture placed on the tile had become firmly set.

Example IV The following basic blend was mixed inasmall Jar mill:

Grams Material 4. 5 Diatomaoeous earth. 0. 9 Potassium alginate. 3.; 8122mm slglnate. b In. rasodium pyro osp l. 25 Aluminum fluosili c ats.

(A) 5 grams of lead monosilicate were added to 7.35 grams of the above basic blend and the resultant mixture was spatulated with 25 cubic centimeters of water (at'70 F.) This spatulated mixture when placed upon a glazed tile produced a good set at the end of six minutes.

(B) 4 grams of lead monosilicate were added to 7.35 grams of the above basic blend and the resultant mixture was spatulated with 25 cubic centimeters of water (at 70 F). This-spatulated mixture when placed upon a glazedtile produced a good set after six minutes.

(C) 3 grams of lead monosilicate were added to 7.35 grams of theabove basic blend and the resultant mixture was spatulated with 25 cubic centimeters of water (at 70 F.) This spatulated mixture was placed upon a glazed tile and a fair set was obtained in six minutes.

.(D) 2 grams of lead monosilicate were added to 7.35 grams of the above basic blend and the resultant mixture was spatulated with 25 cubic centimeters of water (at 70 F.). The spatulated mixture was placed upon a glazed'tile andafter minutes this composition was only slightly set and had a very poor texture.

(E) 5, 10 and 20 grams, respectively, of lead bisilicate were added to three 7.35 gram portions of the above basic mixture. 25 cubic centimeters of water were added to each mixture and after spatulation each resulting composition was placed on a separate glazed tile. After remaining minutes on the tile none of these spatulated compositions had set. Each composition was still in the form of a mush or paste.

Example V The following basic blend was mixed in a small jar mill:

Grams Material 4.50 Diatomsceous earth. 011 Potmum algina g :3 new h h u um p a 0.75 Sodium fiuoslfia s. mp

(A) 5 grams of lead monosilicate were added to 6.85 grams of the above basic blend and the resultant mixture was spatulated with 25' cubic centimeters of water (at 70 F.) The spatulated mixture was placed upon a glazed tile and 2% minutes after spatulation had produced a good set.

(B) 4 grams of lead monosilicate were added to 6.85 grams of the above basic blend and the resultant mixture was spatulated with 25 cubic centimeters of water (at 70 F.-). The spatulated mixture when placed upon a glazed tile produced a good set in six minutes.

with 6.85 grams of the above basic blend and 25 cubic centimeters of water (at 70 F.) were a the constituents in a small jar then added. After spatulation this mixture was placed upon a glazed tile and produced a fair set after six minutes.

(D) 2 grams of lead monosilicate were mixed with 6.85 grams or the above basic blend, 25 cubic centimeters of water (at 70 F.) were added and after spatulation (mixing) this mixture was placed upon a glazed tile. After a period of 20 minutes this composition was very fragile.

(E) 20 grams of lead bisilicate were added to 6.85 grams of the foregoing basic blend, 25 cubic centimeters of water (at 70 F.) were added and the mixture thoroughly spatulated. After twenty minutes from the time of spatulation the composition was still mushy.

Example VI The following basic blend was made by rolling mill.

Grams Material Diatomaoeous earth. fiw i 'h 1..

e um yro as to. Sodium fluosificat p (A) 5 grams of lead monosilicate were mixed with 7.5 grams of the above basic blend, 25 cubic centimeters of water (at 70 F.) were added and the mixture thoroughly spatulated. The spatu- (C) 3 grams of lead monosilicate were mixed I latedmixtureproducedagoodsetinthreeand one-half minutes. I

(B) The foregoing experiment (Example VI (A)) wasrepeatedusin'g4,3and2grams.respectively, in three separate 7.5 gram portions of the basic blend with cubic centimeters of water hadaverymushyconsistencyaftertenminutes.

(C) The foregoing experiment (Example VI (A)) was substituting 20 grams of lead .bisilicate in place of the 5 grams of lead monosillcate. The final composition was still mushy and unsatisfactory minutes after spatulation.

Example VII The following blend was made by mixing the constituentsinasmailjarmill:

mural Dlatomaceous earth.

Aluminum fiifo i l ate.

Lead monosilicnte.

. The above mixture was spatulated with 25 cubic centimeters of water (at '10 F.) and after three minutes produced a very satisfactory set.

Example VIII The following basic formula was made by mixing the ingredients in a small jar mill:

Grams Material Diatomaoeous earth.

Sodium alginate glow viscosity). Sodium alginate medicinal purity). Tetrasodiom pyrophosphate. Aluminum fluosilicate.

(A) 5.0 grams of lead monosilicate were mixed with 7.1 grams of the above basic blend together 25 cubic centimeters of water (at 70 F).

Six minutes after mixing this composition produced a good set.

(B) The foregoing experiment (Example VIII (A)) .was repeated using 4, 3 and 2 gram por-.

tions of lead monosiiicate, respectively with three separate 7.1 gram portions of the basic blend and with 25 cubic centimeters of water (at cubic centimeters of water (at 'm". a). After nrteen minutes this composition had produced a weak set and was unsatisfactory.

Example IX The following basic blend was made by mixing the constituents in a small Jar mill:

'Ietrasodium hos hate Sodium flnosl m p (A) 5 grams of lead monoulicate were mixed with 6.85 grams of the above basic blend and with 25 cubic centimeters of water (at 70" E). After six minutes'this composition produced a good set.

(B) The above experiment (Example IX (A)) was repeated using 4 grams of lead monosilicate.

minutes.

(C) The above experiment (Example IX (Al) was repeated using 3 grams of lead monosilicate. This composition produced a fair set in six minutes.

(D) The above experiment (Example IX (A)) was repeated using 2 grams of lead monosilicate. An unsatisfactory set was obtained at the end of twenty minutes.

(E) The above experiment (Example IX (Al) was repeated using 10 grams oflead monosilicate. A very good set was obtained in three minutes.

(F) The above experiment (Example IX (A)) was repeated using 20 grams of lead monosilicate.

A good set was obtained in about three to four minutes.

(G) The above experiment (Example IX(A)) was repeated using 20 grams of lead bisilicate in place of the lead monosilicate. After thirty minutes this composition was still mushy and had not set.

Example X The following basic blend was mixed in a small jar mill:

Grams Material :3 Ammoni alginate um 65 0.21 Tetrasodi v o. 1. m'sssa (A) 5 grams of lead monosilicate were mixed with 7.25 grams of the above basic blend together with 25 cubic centimeters of water (at 70 F.). This composition produced a good set in one and one-half minutes after mixing.

(B) The above experiment (Example X (A)) was repeated using 4 grams of lead monosilicate. This composition produced a good set in two and one-half minutes after mixing.

' (C) The above experiment (Example X (A)) 70 was repeated using 3 grams of lead monosilicate.

This composition was very fragile after six minutes from time of mixing the final composition.

(D) The above experiment (Example X (A)) was repeated using 2 grams of lead monosilicate.

7 After standing for twenty minutes from the time This composition produced a good set in six The following basic blend was made in a small jar mill:

Grams Material 4. 50 Diatomaeeous 1% T tree s di l iospliata e um yrop 1. 25 Aluminum m oaillcate.

(A) '5 grams of lead monosiiicate were mixed with 7.75 grams of the above basic blend and with 25 cubic centimeters of water (at 70 FL). This composition produced a good set in two minutes.

(B) The above experiment (XI (A)) was repeated using 4 grams of lead monosilicate. This composition produced a good set in two and onehalf minutes.

(C) The above experiment (In (A)) was repeated'using 3 grams of lead monosilicate. This composition was mushy and fragile after ten minutes from the time of mixing.

(D) The above experiment (Xi (A)) was repeated using 2 grams of lead monosilicate. After standing twenty minutes this composition was very mushy and unsatisfactory.

(E) Th above experiment (XI (A)) was repeated using 20 grams of lead bisilicate in place of the lead monosilicate. This composition was mushy after standing twenty minutes.

(A) 0.2 gram sodium carbonate (anhydrous) was mixed with 11.5 grams of the foregoing basic blend and with 25 cubic centimeters of water (at 70 F.). This composition produced a good set in three minutes.

(B) The above experiment (Example HI (A)) was repeated in which the sodium carbonate was replaced with 0.2 gram trisodium phosphate. This composition produced a good set in three minutes.

(C) The above experiment (Example XII (A)) 25 cubic centimeters of water (at 70 F.).

8 Example XIII The following composition was blended:

Grams Material Diatomaoeous earth.

Lead monosilicate. 4

Sodium alginate (low viscosity). Sodium alglnate (medicinal purity).

Sodium iluosillcate.

To the above mixture there was added .05 gram primary sodium phosphate and 25 cubic centimeters of water and this composition was then thoroughly mixed. This composition produced a good set in two minutes.

0 Example XIV I The following basic blend was obtained b mixing in a small jar mill:

Grams Material 00 Diatomaeeous earth 200 Lead monosilicate 40 Pectin methoxyl.

4 Tetrasodium pyrophosphate.

(A) 19.5 of the above basic blend was mixed with .350 gram of aluminum fiuosilicate and 25 cubic centimeters of water (at 70 F.) This composition produced a good set in six minutes.

(B) 21 grams of the above basic blend was mixed with 0.250 gram of sodium fiuosilicate and This composition produced a good set in five minutes.

Example XV The following ingredients were mixed together:

was repeated in which the sodium carbonate was replaced by 0.2 gram of sodium meta phosphate. This composition produced a good set in two minuta.

(D) The above experiment (Example XII (A)) was repeated using 0.1 gram potassium diphosphate in place of the sodium carbonate. This composition produced a fair set in twenty minutes.

Material Diatomaceous earth.

Lead monosilicate. Potassium alginate. Sodium alginate (medicinal purity). Tetrasodium pyrophosphate. Sodium carboxymethyl cellulose. Aluminum iluo silicate.

The above basic blend was mixed with 25 cubic centimeters of water (at 70 F.) This composition produced a good set in seven minutes.

Example XVI The following basic blend was mixed in a small jar mill:

Grams Material 40.0 Diatomaceous earth. 150. 0 Lead monosilicate.

l0. 0 Sodium carhoxymethyl cellulose.

. 9' ExamplexVII The 'iollowing basic blend was made in a small jar mill: 4

Grams Material 90. Diatomaceous earth. 200 Lead monosilicate.

18 Potassium alginate; Sodium alginatc (medicinal purity).

4 Tetrasodium s1gyrophosphate. 10 Sodium fluo 'cate.

34 grams of the above composition were mixed with 50 cubic centimeters of water (at 10 F.). This composition produced a very satisfacto y set in two and one-half minutes when placed upon a glazed tile.

To clarify what is meant by the term setting time in Examples I to XVII, inclusive, all of the compositions with the added water were mixed or spatulated in a flexible rubber cup with an ordinary steel spatula, after which the contents of the cup were placed upon a glazed tile. The times shown in the foregoing examples are taken from the time the water is added to the composition and start of spatulation.

In addition to using lead monosilicate I may also use lead disilicate. Both of these compounds are orthosilicates. Lead bisilicate is the metasilicate and, as stated above, is unsatisfactory in my composition.

I claim:

1. [A] An impression composition [of matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali metal alginate, [salt of a weak organic acid selected from the group consisting of pectic, alginic, and methylcarboxycellulose acids,] sodium fluosilicate and lead orthosilicate.

2. [A] An impression composition [of matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali metal alginate, sodium fiuosilicate, lead orthosilicate and an alkali metal phosphate.

3. [A] An impression composition [of matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali metal alginate, sodium fluosilicate, lead orthosilicate and an alkali metal carbonate.

4. [A] An impression composition [of matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali metal alginate, [salt of a weak organic acid selected from the group consisting of pectic, alginic and methylcarboxycellulose acids,] a fluosillcate, lead monosilicate and an alkali metal phosphate.

5. [A] An impression composition [of matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali metal alginate, sodium fluosilicate,- lead monosilicate, an alkali metal pyrophosphate and a filler.

6. [A] An impression composition [of matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali metal alginate, [salt 0! a weak organic acid selected from the group consisting of pectic, alginic and methylcarboxycellulose acids,] a fluosilicate, lead disilicate, an alkali metal carbonate and a filler.

'l. [A] An impression composition [of matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali l0 ,1 metal alginate, sodium fluosilicate. lead disilicate, an alkali metal phosphate and a filler.

8. [A] An impressioncomposition [of matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali metal alginate, sodium fluosilicate, lead disilicate, an alkali metal pyrophosphate and a filler.

9. [A] An impression composition [of matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali metal alginate, sodium fluosilicate, at least 34.1% oi lead monosilicate, an alkali metal pyrophosphate, and a filler.

10. [A] An impression composition [of matter comprising] convertible by mixing withwater to an elastic'gel consisting essentially of an alkali metal alginate, sodium fluosilicate, at least 34.1% of lead monosilicate, an alkali metal carbonate and a filler.

11. [A] An. impression composition [0! matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali metal alginate, [salt of a weak organic acid selected from the group consisting of pectic, al-

ginlc and methylcarboxycellulose acids,] as fluosilicate, lead monosilicate, .a filler, and an ala kali metal carbonate.

12. [A] An impression composition [of matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali metal alginate, [salt of a weak organic acid selected from the group consisting of pectic, alginic and methylcarboxycellulose acids,] a-fluosilicate, lead disilicate, a filler and an alkali metal phosphate.

13. [A] An impression composition [0! matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali metal alginate, sodium fluosilicate, lead monosilicate, an alkali metal phosphate and a filler in which composition the ratio of sodium fluosilicate to lead monosilicate is between 1 to 3 and 1 to 20.

14. [A] An impression composition [of matter comprising] convertible by mixing with water to an elastic gel consisting essentially of an alkali metal alginate, sodium fluosilicate, lead monosilicate, an alkali metal carbonate and a filler in which the ratio 01 sodium fluosilicate to lead monosilicate is between 1 to 3 and 1 to 20.

15. [A] An impression composition [oi matter] as claimed in claim 4 in which the fluosilicate is aluminum fluosilicate.

16. [A] An impression composition [of matter] as claimed in claim 6 in which the fluosilicate is aluminum fluosilicate.

17. [A] An impression composition [of.mat-

ter] as claimed in claim 11 in which the fluo silicate is aluminum fluosilicate.

18. [A] An impression composition [oi matter] as claimed in claim 12 in which the fluosilicate is aluminum fluosilicate.

19. An impression composition convertible by mixing with water ,to an elastic gel comprising an alkali metal salt of pectic acid, sodium fluosilicate and lead orthosilicate.

20. An impression composition convertible by mixing with water to an elastic gel comprising an alkali metal salt of pectic acid, a fluosilicate, lead monosilicate and an alkali metal phosphate.

21. An impression composition convertible by mixing with water to an elastic gel comprising an alkali metal salt of pectic acid, a fiuosilicate, Leg: disilicate, an alkali metal carbonate and a 22. An impression composition convertible by mixing with water to an elastic gel comprising an alkali metal salt of pectic acid, a fluosilicate, lead monosilic'ate, a filler and an alkali metal carbonate.

.23. An impression composition convertible by mixing with water to an elastic gel comprising an alkali metal salt of pectic acid, a fiuosilicate, lead disilicate, .a filler and an-alkali metal phosphate 24. An impression composition convertible by mixing with water to an elastic gel comprising an alkali metal salt of methplcarboavcellulose,

' sodium flaosilicate and lead orthosilicate.

25. An impression composition convertible by mixing with water to an elastic gel comprising an alkali metal salt of methglcarbortgeellulose, a fluos'ilicate, lead monosilicate and an alkali metal phosphate.

.26. An impression composition convertible by mixing with water to an elastic gel comprising an alkali metal salt of methplcarboxgcellulose, a fluosilicate, lead disilicate, an alkali metal carbonate and a filler.

27. An impression composition convert ble by mixing with water to an elastic gel comprising an alkali metal salt of me'thvlcarborgcellulose, a fluosilicate, lead monosilicate, a filler and an alkali metal carbonate,

28. An impression composition convertible by mixing with water to an elastic gel comprising i an alkali metal salt of methglcarboxgcellulose, a flnosilicate, lead disilicate, a filler and an alkali metal phosphate.

EDWIN H.

References emu m the file of this patent or the original patent UNITED STATES PA-TENTS Number Name Date 2,422,497 Noyes June 17, 1947 2,424,895 Noyes July 2a, 1947 2,425,118 Noyes Aug. 5, 1947 Noyes Jan. 8, 1948