RU2158564C1 - Method for treating artificial denture - Google Patents

Abstract

FIELD: medicine. SUBSTANCE: method involves applying coating containing gold as the base with hard zirconium oxide inclusion to the surface of a corrosion- proof alloy as follows. First, the prosthesis is plunged into gilding electrolytes, hold therein under known current density, temperature, during some time and under continuous mixing followed by washing and drying. EFFECT: high wear resistance properties and biocompatibility with organism tissues. 2 tbl

Description

 The invention relates to medicine, namely to dentistry.

 A known method of processing dentures by electrochemical coating based on a gold alloy on a corrosion-resistant alloy, which includes a number of sequential operations: degreasing, etching in 25% hydrochloric acid, rinsing in water, electrolytic treatment of the prosthesis in a solution of composition No. 1 according to mode No. 1, then in a solution of N 2 according to the regime of N 2, washing and drying.

Composition N 1 (wt.%)
Trivalent gold salt (for example, K {Au (CN) ₄ } ^-
Potassium tetracyanoaurate - 0.25
Cobalt Chloride - 0.03
Citric Acid - 8.0
Amines (e.g. aminoalkanes) - 0.2
Hydrochloric acid - The rest, up to pH <1
Composition N 2 (wt.%)
Potassium Dicyanoaurate - 0.5
Nickel sulfamic acid - 0.4
Nitrilotriacetic acid - 1.7
Potassium Citrate - 6.0
Formic acid - 1.2
Boric acid - 2.0
Brightening agent, for example Limeda - 0.1
Water - Else
while the exposure time in an electrolyte of composition No. 1 (mode No. 1) is 3-6 minutes at a voltage of 4-5 V, and in an electrolyte of composition No. 2 (mode N2) is 30-50 minutes at a voltage of 2-4 V. The method is carried out at room temperature. At the end of the process, the prosthesis is washed in water and dried. This method is taken as a prototype.

(Pat. N 2036622 RF IPC ⁶ A 61 C 31/02. Method of processing dentures. Kopeikin V.N., Safarova N.I., Safarova K.Yu., Lebedenko I.Yu., Lebedenko A.I. / Safarova N.I. Bull. 1995, N 16, p. 86).

 The disadvantage of this method of processing dentures is the lack of wear resistance of the coating, its potential carcinogenicity and allergy due to the presence of nickel in it, as well as the complexity of execution due to the complex composition of electrolyte N 1.

 The objective of the invention is to increase the wear resistance of the gold coating, ensuring its biocompatibility with the human body, simplifying the processing method by changing the chemical composition of electrolytes.

 An increase in the wear resistance of the denture coating is achieved by including zirconium oxide in the composition of N 2 electrolyte, the elimination of nickel from the N 2 electrolyte ensures its biocompatibility with the human body, the method is simplified by changing the composition of the N1 electrolyte, including potassium dicyanoaurate, citric acid and water.

 The method is as follows.

The metal surface of a denture made of a corrosion-resistant alloy is degreased and etched in a 25% hydrochloric acid solution. After a short wash in water, the prosthesis is placed in an electrolyte of composition N 1, including potassium dicyanoaurate, citric acid, water, wt.%:
Potassium Dicyanoaurate - 0.15
Citric Acid - 8.0
Water - the rest
pH 1-1.5
The exposure time in an electrolyte of composition N 1 is 8 - 10 min at a current density of 0.3-0.5 A / dm ² , then the prosthesis is washed in water and immersed in an electrolyte of composition N 2, including potassium dicyanoaurate, cobalt sulfate, trilon A, citric acid, potassium tri-substituted citric acid, zirconium oxide, brightening additive, surfactant, water, wt. %:
Potassium Dicyanoaurate - 1.0
Cobalt Sulphate - 0.1
Trilon A - 0.25
Citric Acid - 3.0
Three-substituted potassium citrate - 6.0
Zirconium oxide - 0.5
Brightening Additive - 0.008
Surfactant - 0.008
Water - Else
set the current value corresponding to a current density of 0.8 - 1 A / DM ² and incubated for 2 to 2.5 hours to build up the main layer of the gold alloy.

 The whole method is carried out at room temperature and constantly stirring the electrolytes by reciprocating the cathode rod, on which the prosthesis is fixed, after which the prosthesis is removed from the electrolyte, washed in water and dried.

 Example: Patient N., 55 years old, suffering from a generalized form of periodontitis complicated by secondary partial adentia of the lower jaw, shows the manufacture of a cast cast splint arch prosthesis from a high-strength cobalt-chromium alloy (KHS).

 An indication for the treatment of the clasp prosthesis by applying a gold coating to the cobalt-chromium alloy prosthesis frame was the patient's sensation of a taste of metal and burning in the oral cavity.

The gold coating was carried out in electrolytic baths. The prosthesis was thoroughly degreased, etched in a 25% hydrochloric acid solution for 1 - 1.5 minutes, washed in water and hung on a copper contact fixture in an electrolyte of composition 1, wt.%:
Potassium Dicyanoaurate - 0.15
Citric Acid - 8.0
Water - Else
pH 1-1.5
The process was carried out at room temperature. The current value was set corresponding to the current density of 0.3-0.5 A / dm ² , the exposure time was 8 - 10 minutes.

At the end of the process, the prosthesis was removed from the electrolyte of composition N 1, washed with water and placed in an electrolytic bath with composition N 2, wt.%:
Potassium Dicyanoaurate - 1.0
Cobalt Sulphate - 0.1
Trilon A - 0.25
Citric Acid - 3.0
Potassium citric acid 3 substituted - 6.0
Zirconium oxide - 0.5
Brightening Additive - 0.008
Surfactant - 0.008
Water - Else
The process was carried out at room temperature. Set the current value corresponding to a current density of 0.8-1 A / dm ² . The exposure time was 2-2.5 hours with constant stirring of the electrolyte due to the reciprocating motion of the cathode rod.

 After washing in water and drying, the prosthesis was placed in the patient's oral cavity. Changes in the plastic parts of the prosthesis during visual inspection were not detected.

 The subjective sensation of the patient is good. The patient is pleased with the absence of a taste of metal, the high cosmetic effect of the prosthesis, and the shiny surface of the gold coating. During follow-up examinations after 6 months, 1 year and 1.5 years, there were no complaints of the patient about a burning sensation and a taste of metal. Spot abrasion of the coating was revealed after a control inspection 2.5 years after the manufacture of the prosthesis. The gold plating was restored according to the described method. The introduction of zirconium oxide in the composition of the gold coating allowed to increase the wear resistance, and therefore, the service life of the gold coating by 30% (due to an increase in microhardness), compared with the prototype method (see table. 1).

Claims (1)

A method of processing dentures by applying a gold alloy to a corrosion-resistant alloy, comprising sequentially immersing the prosthesis in electrolytes of two compositions, keeping them at a given current value and temperature and constant stirring, washing and drying, characterized in that they use N1 as an electrolyte a solution containing a salt of monovalent gold, citric acid, water, taken in the following proportions, wt.%:
Potassium Dicyanoaurate - 0.15
Citric Acid - 8.0
Water - Else
pH - 1 - 1.5
the exposure time in an electrolyte of composition N1 is 8-10 minutes at a current density of 0.3 - 0.5 A / dm ² and room temperature, and as an electrolyte of composition N2, a solution containing a monovalent gold salt, cobalt sulfate, Trilon A is used , citric acid, potassium citric acid trisubstituted, zirconium oxide, brightening additive, surfactant, water, taken in the following proportions, wt.%:
Potassium Dicyanoaurate - 1.0
Cobalt Sulphate - 0.1
Trilon A - 0.25
Citric Acid - 3.0
Three-substituted potassium citrate - 6.0
Zirconium oxide - 0.5
Brightening Additive - 0.008
Surfactant - 0.008
Water - Else
while the exposure time in an electrolyte of composition N2 is 2 - 2.5 hours at a current density of 0.8 - 1 A / dm ² and room temperature, with constant stirring due to the reciprocating motion of the cathode rod.

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