RU199739U1 - LOADING DEVICE FOR PRODUCING SAMPLES OF DENTAL FIXING MATERIAL - Google Patents

Abstract

The loading device for making samples of dental luting material belongs to dentistry and can be used to determine the film thickness and adhesive strength. The device contains a body, base, clamping part, lever and weight. In this case, the base and the clamping part are located on the body in the upper part of the device. The load is located under the base with the ability to move when changing the position of the lever by means of a cable. The clamping part is made movable in the form of a truncated cylinder with the possibility of balancing on a shaft connected to the load. The proposed device provides a uniform distribution of dental material between the plates and the formation of a film of the same thickness over the entire area due to the compensation of distortions due to the non-parallelism of the plates through the use of a movable clamping part. The technical result is to expand the possibility of using a loading device for determining, along with the film thickness, also the adhesive strength of the dental material under study to materials used, for example, for the manufacture of fixed dentures, such as stainless steel, cobalt-chromium alloy, zirconium dioxide, etc. ., by providing the possibility of making standardized samples of dental material and obtaining test results with a low value of the coefficient of variation, even when using non-flat-parallel plates.

Description

The utility model relates to measuring technology, namely to devices for measuring linear dimensions, and can be mainly used for making samples of dental fixing material in the form of a film between plates for measuring the film thickness of dental fixing material.

A loading device according to GOST 31578-2012 for determining the thickness of a dental cement film is known from the state of the art. This device is taken as a prototype. The loading device contains a body, a base, a clamping part, a lever and a weight, which, under the action of the lever, is lowered onto the clamping part.

When making a sample (Fig. 1a), according to GOST 31578-2012, measure the total thickness of two optically flat glass plates 3 and 5 folded together. The upper plate 3 is removed, 0.5 cm ^{3 of} mixed dental material 4 is placed in the center of the lower plate 5 and the plate is placed with cement on the base 1 of the loading device so that the cement sample is located in the center of the load application. From above, the cement is covered with an upper glass plate 3 so that the position of the plates corresponds to the position of the initial measurement of their thickness. 10 s before the end of the working time specified in the manufacturer's instructions, apply a load (150 ± 2) N by the clamping part 2 perpendicular to the center of the upper plate 3. Make sure that the dental material 4 completely fills the space between the plates 3 and 5. At least than 10 minutes after the start of the application of the load, the sample is removed from the loading device and the total thickness of the plates with the dental material film is measured. The difference between the thickness of the plates with the film and the plates without the film is considered the film thickness of the dental material.

The disadvantage of this technical solution is the need to use only glass plates with strictly plane-parallel sides, which limits the possibility of using the device solely by measuring the thickness of the dental material film. In this case, if at least one of the sides of the glass plate is not strictly plane-parallel, the skew compensation occurs due to the uneven distribution of the material between the plates, therefore it is not possible to obtain a film of dental material of the same thickness over the entire area and, accordingly, to obtain correct measurement results is not possible. ...

The task of the utility model is to expand the possibility of using a loading device for determining, along with the film thickness, the adhesive strength of the dental material under study to materials used, for example, for the manufacture of fixed dentures, such as stainless steel, cobalt-chromium alloy, zirconium dioxide, etc. etc.

The technical result is an increase in the measurement accuracy due to the possibility of making standardized samples of dental material in the form of a film of the same thickness over the entire area, both when using non-flat glass plates and plates made of materials used for the manufacture of fixed dentures, for example, stainless steel, cobalt chrome alloy, zirconium dioxide, etc. Plates made from materials intended for the manufacture of fixed dentures, such as stainless steel, cobalt-chromium alloy, zirconium dioxide, etc., are difficult to make plane-parallel. As a result, the compensation of skews due to the non-parallelism of the plates occurs due to the uneven distribution of material between them, therefore, it is not possible to obtain a film of the same thickness over the entire area and, accordingly, correct measurement results are not possible (Fig. 1b). Therefore, the possibility of using plates with non-parallel sides in the preparation of samples of dental materials will allow obtaining research results with a low value of the coefficient of variation, as well as expanding the range of use of the device and, in the case of using plates made of materials intended for the manufacture of fixed dentures, to determine not only the film thickness, but and the amount of adhesion of the dental material under study to the material from which the plates are made.

The task is solved by introducing the following new features into the loading device for determining the film thickness of dental cement, which contains the body, base, clamping part, lever and weight:

- the base and the clamping part are located on the body in the upper part of the device;

- the load is located under the base with the ability to move when changing the position of the lever by means of a cable, which allows the load from the load to be applied through the clamping part to the upper plate of the sample smoothly and provides compensation for the skew when using plates with non-flat sides;

- the clamping part is made movable in the form of a truncated cylinder with the possibility of balancing on a shaft connected to a weight, which ensures uniform distribution of dental material between the plates, i.e. formation of a film of the same thickness over the entire area, due to the compensation of distortions due to the non-parallelism of the plates.

The essence of the utility model is illustrated by drawings, which show:

Figure 1 - Manufacturing on a loading device prototype of a sample of a film of dental material a) between plane-parallel plates b) between non-plane-parallel plates, where 1 is the base; 2 - clamping part; 3 - upper plate; 4 - dental fixing material; 5 - bottom plate.

Figure 2 - Diagram of the movable clamping part, made in the form of a truncated cylinder 12 with the possibility of balancing on the shaft 11, connected to the weight 7.

Figure 3 - Diagram of the loading device, where 1 - base; 2 - movable clamping part; 3 - upper plate; 4 - dental fixing material; 5 - bottom plate; 6 - lever, 7 - weight, 8 - fixed block, 9 - cable, 10 - body.

Figure 4 - Manufacturing a sample of a film of dental material on the proposed loading device a) between plane-parallel plates b) between non-plane-parallel plates, where 1 is the base; 2 - clamping part, 3 - upper plate, 4 - dental fixing material, 5 - lower plate.

The proposed loading device for the manufacture of dental fixing material samples in the form of a film between the plates (Fig. 3) can be used in the manufacture of dental material samples between plane-parallel (Fig. 4a) and non-parallel (Fig. 4b) glass plates to determine the film thickness, as well using non-flat-parallel plates made of any material suitable for the manufacture of a fixed denture and hard tooth tissues to determine the adhesive strength.

The device works as follows. A sample is prepared by placing the dental material 4 between the flat surfaces of the lower plate 3 and the upper plate 5. The lever 6 is lowered down and, using the cable 9 through the fixed block 8, the weight 7 is brought to the upper position together with the clamping part 2, which is mounted on the shaft 11 truncated cylinder 12 with the possibility of balancing on the specified shaft. The obtained sample is placed on the base 1 of the loading device so that the sample is located in the center of the load application and, lifting the lever 6 upwards, the load is applied by the clamping part 2 perpendicular to the center of the upper plate 3. In this case, the compensation of the skew due to the non-parallelism of the plates is carried out due to the possibility of changing the position of the truncated cylinder 12 (figure 4b). After the expiration of the period of application of the load, the lever 6 is lowered down and the plates 3 and 5, fastened with a film of dental fixing material 4, are removed from under the clamping part. The film thickness is then measured, and in the case of using non-glass plates, the adhesion strength of the sample is measured.

Specific examples of using the proposed device.

Example 1.

A sample of polycarboxylate dental cement in an amount of 0.5 cm ³ is positioned between non-parallel zirconia plates. A load is applied to the loading device according to the prototype. Measurements of the thickness of the resulting cement film are carried out at three points on a given sample.

Example 2.

A sample of polycarboxylate dental cement in an amount of 0.5 cm ³ is positioned between non-parallel zirconia plates. A load is applied using the proposed loading device. Measurements of the thickness of the resulting cement film are carried out at three points on a given sample.

The results are presented in the table.

The table shows that when using the proposed device, a cement film is formed, the thickness of which at three points differs by no more than 6%. When using the prototype, the minimum and maximum obtained values of the film thickness differ by 28%. Thus, the use of the proposed loading device makes it possible to obtain more reliable test results for determining the thickness of the film, regardless of the material from which the plates are made and without observing the condition of plane-parallelism of the sides of these plates, including with only one flat side. In this case, after determining the thickness of the film, it is possible to determine the value of adhesion of the studied dental material to the material from which the plates are made.

Example 3.

To test the adhesive strength in shear, 5 samples of polycarboxylate dental cement were made between non-planar plates of zirconium dioxide using the proposed loading device according to example 2. The prepared samples were immersed in a vessel with distilled water and left for 24 hours in a thermostat at a temperature of (37 ± 1) ° C. Before testing, the samples were removed from the water and moisture was removed from their surface. The samples were mounted in an Instron shear test fixture. The test was carried out until the glued sample was completely destroyed at a crosshead speed of 5 mm / min. According to the test results, the adhesion of polycarboxylate cement to zirconium dioxide averaged 7.050 ± 0.681 MPa.

Consequently, the task has been achieved. In this case, the proposed base of the loading device can be used not only for the study of dental materials.

Claims (1)

A loading device for making samples of dental fixing material in the form of a film between plates, comprising a body, a base, a pressing part, a lever and a weight, characterized in that the base and the pressing part are located on the body in the upper part of the device; the load is located under the base with the ability to move when changing the position of the lever by means of a cable; the clamping part is made movable in the form of a truncated cylinder with the possibility of balancing on a shaft connected to the load.

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