# US 4,394,172 A · Non-dusting and fast-wetting impression material and method of preparing same

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- Number: US 4,394,172 A
- Document ID: US4394172A
- Status: Granted
- Kind: A
- Application number: 06/293,143
- Filed: 1981-08-17
- Granted: 1983-07-19
- Earliest claimed: 1980-08-26
- Assignees: Dentsply Research & Development Corp.
- Inventors: Max Scheuble; Paul Munsch
- Web page: https://patentgrep.com/patent/US4394172A

## CPC

- A61K 6/90: Compositions for taking dental impressions
- C08L 5/04: Alginic acid; Derivatives thereof
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

A non-dusting and fast-wetting powdered impression material is prepared by coating at least a portion of the powder components of an otherwise conventional impression material with a surface coating agent prior to mixing with water.

## Claims

### Claim 1

In a dry powdered impression material comprising an alginic acid salt component and a filler component, wherein said material exhibits a tendancy toward dusting in its dry powdered state, wherein said material is mixable with water to form an impression paste capable of setting to a solid, and wherein said material exhibits a further tendancy toward dusting upon admixture with water, the improvement comprising a coating on at least a portion of the powdered components rendering said material substantially non-dusting in its dry powdered form and during admixture with water, said coating being readily and rapidly wet, dispersed or dissolved by water and present in an amount of from about 1-10% by weight based on the total weight of the dry powdered components.

### Claim 2 (depends on 1)

The impression material of claim 1, wherein said coating agent is selected from the group consisting of natural polymer dispersing agents, cellulose ester and ethers having ester or ether groups containing free hydroxyl or carboxyl groups and synthetic nonionic polymeric surfactants.

### Claim 3 (depends on 1)

The impression material of claim 1, wherein said coating agent is selected from the group consisting of xanthan gum, hydroxyethyl or hydroxymethyl cellulose, carboxy methyl cellulose, sodium polyalginate or potassium polyalginate, polyethylene glycol or polypropylene glycol or polybutylene glycol or copolymers thereof, ethylene glycol, propylene glycol, triethanolamine lauryl sulfate, sucrose butyrate, glycerol esters and mixtures thereof.

### Claim 4 (depends on 1)

The impression material of claim 1 consisting essentially of the following components in admixture:
______________________________________ Component Parts by Weight ______________________________________ sodium alginate or potassium alginate 14.0 calcium sulfate 17.4 tetrasodium pyrophosphate 2.5 potassium titanium fluoride 1.0 magnesium oxide 2.6 diatomaceous earth 57.8 polypropylene glycol 4.7, ______________________________________
wherein said diatomaceous earth had been coated with said polypropylene glycol prior to having been mixed with the remaining components.

### Claim 5 (depends on 1)

The impression material of claim 1 consisting essentially of the following components in admixture:
______________________________________ Component Parts by Weight ______________________________________ sodium alginate 8.5 potassium alginate 8.5 magnesium oxide 3.0 magnesium carbonate 4.0 potassium fluorotitanate 4.1 calcium sulfate 17.0 sodium fluoride 0.5 sodium tripolyphosphate 1.5 potassium diphosphate 1.3 polypropylene glycol 3.5 diatomaceous earth 48.0 ______________________________________
wherein said diatomaceous earth had been coated with said polypropylene glycol prior to having been mixed with the remaining components.

### Claim 6

A method for controlling the dusting of a powdered impression material comprising coating at least a portion of the powder with from about 1-10% by weight, based on the total weight of the powdered components, of an agent which when dry renders the powder, in its dry powder form, relatively non-dusting.