RU2390317C1 - Method for thixotropy testing of dental materials and device for implementation thereof - Google Patents

Abstract

FIELD: medicine. ^ SUBSTANCE: group of inventions refers to medical equipment and can be used in orthopaedic dentistry for thixotropy testing of cast dental materials. A device for thixotropy testing of the cast dental materials comprises a transparent cylinder wherein in its top, there is a piston with a rod, and thereunder there is a limiter with a capillary directed to a cylinder bottom to form a chamber for the cast dental material between the piston and limiter; a load tank with a cover mounted on the opposite side of the rod. The transparent cylinder is fixed in an opening of the frame fixed on a base. On the piston rod, there is a stopper for the piston stroke limitation. The transparent cylinder, stopper and capillary are calibrated in mm. The method implies that with using a device under cl.1, triple pressure of one weight load is exerted on equal volume of each analysed cast material. ^ EFFECT: ensured adequate comparative thixotropy testing of cast dental materials. ^ 2 cl, 1 dwg

Description

The invention relates to the field of medical equipment and can be used in orthopedic dentistry to determine the thixotropy of impression dental materials.

Thixotropy - the ability of a material to become fluid under pressure, and practically non-fluid without pressure. The instructions for the use of impression dental materials indicate the presence of this property, but an abstract terminology is used as an estimate of the degree of thixotropy - “a high degree of thixotropy”.

Known capillary viscometer containing a working cylinder with a plunger inside, a floating capillary, a transition head and a device for measuring axial force, and the end of the cylindrical protrusion in the transition head is made in the form of an inverse cone, and the working cylinder is mounted horizontally [1].

The device allows to increase the accuracy of measuring viscosity.

A device for measuring viscosity is known, comprising a cylindrical container, a piston with an integrated capillary connected to the base with a bell, a loading system, the outer surface of the piston being made in the form of a truncated cone, the diameter of the larger base of which is equal to the diameter of the larger base of the bell, and the height is greater than the height of the bell on the length of the capillary [2].

The device improves the accuracy and reliability of viscosity measurements.

A constant flow capillary viscometer is known, comprising a dispenser, a capillary and a differential pressure measuring unit, the dispenser being made in the form of a cylinder with a piston, and the differential pressure measuring unit consists of two sections separated by a membrane, one of which serves a measured medium, and the other is filled buffer fluid [3].

The device increases the sensitivity of measurements of volatile liquids.

Known capillary viscometer containing a housing with a chamber fixed to it with a piston and a capillary located in its lower end part, a spring loading device that provides a pair of the flat surface of the springs with the profiled surface of the housing, a measurement system, while the profiled surface is made staggered with placed on its horizontal sections of the supports [4].

The device improves the accuracy of viscosity measurements.

The technical result of the invention is a reliable comparative assessment of the thixotropy of impression dental materials.

For an objective assessment of this parameter, a method and device are proposed.

The technical result is achieved due to the fact that the device for determining the thixotropy of dental impression materials contains a transparent cylinder, inside of which there is a piston with a rod in the upper part and a stopper with a capillary directed to the bottom of the cylinder with the possibility of forming a chamber between the piston and the stopper for placement impression material, a cargo tank with a lid mounted on the opposite side of the rod, while the transparent cylinder is fixed in the hole of the frame, fixed based on the piston rod is mounted a stopper for limiting the stroke movement of the piston, a transparent cylinder, corkscrew and capillaries made with calibration in mm.

The technical result is also achieved due to the fact that the method of determining the thixotropy of various dental bonding materials consists in the fact that the same volume of each investigated bonding material is exerted three times by a load of the same weight, using the device according to claim 1, and the piston and rod are removed with a cargo tank of a transparent cylinder and fill the chamber with impression material to a height of 20 mm from the stopper with a capillary, install a piston with a cargo tank, fix the required pore stroke They use a stopper on the rod to place the cargo in a cargo tank, after the impression material has entered the capillary and the piston stops, the movement of the impression material inside the capillary is measured, then the stopper is shifted twice more by a predetermined amount and the movement of the impression material inside the capillary is measured, and then, according to comparative data, it is determined thixotropy of the studied materials.

The invention is illustrated in the drawing.

A device for determining the thixotropy of dental impression materials contains a transparent cylinder 1, inside of which a piston 2 with a rod 3 and a stop 4 with a capillary 5 directed to the bottom of the cylinder are located in the upper part of it. A chamber is formed between the piston and the limiter to accommodate the impression material. A cargo tank 6 with a cover 7 is installed on the opposite side of the rod 3. A transparent cylinder 1 is fixed in the hole of the frame 8, mounted on the base 9. A stopper 10, for example a lock ring, is installed on the piston rod 3, to limit the travel of the piston 2. Transparent cylinder 1 , rod 3 and capillary 5 are calibrated in mm.

A method for determining the thixotropy of various dental binders is that they apply three times the load of the same weight to the same volume of each of the investigated binders using the device described above. To implement the method, remove the piston 2 and the rod 3 with a cargo capacity of 6 from the transparent cylinder 1 and fill the chamber with the test cast material to a height of 20 mm from the stop 4 with a capillary 5, install the piston 2 and the rod 3 with a cargo capacity of 6, fix the required piston stroke 2 the stopper 10 on the rod 3, place the load 11 in the cargo tank 6. After the impression material enters the capillary 5 and the piston 2 stops, the movement of the impression material inside the capillary 5 is measured. To increase the accuracy of the measurements, the stopper 10 is moved twice this value and measure the movement of the impression material inside the capillary 5. In this way, the thixotropy of all the studied impression materials is measured and their suitability for a particular type of dental work is determined by comparative data.

Example.

We study the thixotropy of impression materials: Imregum Duo Soft (3m-Espe) and S-4 (Bisico).

The study is carried out on a device consisting of a transparent cylinder, inside of which a stop with a capillary is installed in the upper third for uniform accumulation of the test mass. In the upper part of the cylinder there is a piston with a stopper on its rod and a cargo container with a cover. The whole structure is mounted on a frame fixed to the base. Using this device, Imregum Duo Soft (3m-Espe) and S-4 (Bisico) impression materials were alternately loaded into the camera. A piston with a cargo capacity is removed from the transparent cylinder and filled with the investigated cast mass to a height of 20 mm flush with the edge of the cylinder. In this way, the same amount of all the materials under study is ensured. Set the piston with the container for the load back, lay the load with the same weight for all the materials studied, for example 400 g. When the piston is moved under the pressure of the load, the impression mass enters the capillary. After the termination of the pressure (stopping the piston), the distance of the mass displacement inside the capillary is measured in mm. The best result is the smallest mass movement in mm inside the capillary after the piston pressure ceases.

Then the stopper is displaced, and the piston moves 5 mm more under the load. After similar measurements, the piston is again moved 5 mm to the lower organizer, which is also 5 mm. Thus, triple pressure was exerted on a single studied cast mass. The following results were obtained:

Imregum Duo Soft (3m-Espe)

The piston is offset by 10 mm — the mass displacement distance inside the capillary is 21.3 mm.

The piston is offset by 5 mm - the distance of the mass movement inside the capillary is 8.2 mm.

The piston is offset by 5 mm - the distance of the mass movement inside the capillary is 8.2 mm.

The total distance of the movement of mass inside the capillary is 37.7 mm

S-4 (Bisico)

The piston is offset by 10 mm - the distance of the mass movement inside the capillary is 38.1 mm.

The piston is offset by 5 mm - the distance of the mass movement inside the capillary is 15.3 mm.

The piston is offset by 5 mm - the distance of the mass movement inside the capillary is 15.2 mm.

The total distance of movement of the mass inside the capillary is 68.6 mm. Thus, on the example of the two studied materials, a significant difference in the degree of thixotropy was revealed, which is important for indications for their practical use. So materials with high thixotropy should be used when working with toothless jaws and the manufacture of complete removable dentures. When using them, the material does not flow down the back wall of the pharynx and does not create guy lines displaying the transition folds when forming the borders of removable prostheses. In turn, materials with low thixotropy should be used when there is a need to display such hard-to-reach areas as, for example, tooth roots in the manufacture of intra-channel pin tabs, etc.

Information sources

1. Auth. testimonial. SU 667866, publ. 06/26/1979.

2. Auth. testimonial. SU 688867, publ. 10/01/1979.

3. Auth. testimonial. SU 120470, publ. 04/15/1968.

4. Auth. testimonial. SU 594433, publ. 06/26/1079.

Claims (2)

1. A device for determining the thixotropy of dental impression materials, containing a transparent cylinder, inside of which there is a piston with a rod in the upper part and under it a stopper with a capillary directed to the bottom of the cylinder, with the possibility of the formation of a cargo box between the piston and the stopper for placing dental impression material a container with a lid mounted on the opposite side of the rod, while a transparent cylinder is fixed in the hole of the frame, mounted on the base, on the pore rod a stopper is installed for the piston to limit the stroke of the piston, and the transparent cylinder, corkscrew and capillary are calibrated in millimeters. 2. The method of determining the thixotropy of various dental impression materials, which consists in the fact that the same volume of each studied impression material is applied three times with a load of the same weight using the device according to claim 1, while the piston with the rod and cargo capacity is removed from the transparent cylinder and filled chamber with impression material to a height of 20 mm from the stopper with a capillary, a piston with a cargo capacity is installed, the required piston stroke is fixed with a stopper on the rod, the cargo is placed in the cargo tank st, after hitting impression material to the capillary stop and the piston displacement of the impression material is measured inside the capillary, then twice again displace the stopper by a predetermined amount and measuring the movement of the impression material within the capillary and then the data is determined thixotropy comparative test materials.

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