RU2808378C1 - Dental diamond separating disc with wear-resistant nano-coating - Google Patents

Abstract

FIELD: medical equipment.

SUBSTANCE: invention can be used in orthopaedic dentistry for separating the prepared tooth from neighbouring teeth during prosthetics under an artificial crown, making one smooth movement from the chewing surface to the interdental papilla. A dental separation disc for preparing teeth contains a working part on which a multilayer coating is applied. The working part of the instrument, made of a nickel base, the surface of which is coated with diamond powder, is coated using atomic layer deposition technology with a three-layer nanocoating, the total thickness of which is 100 nanometres. The first coating layer, which is the substrate, is made of aluminium oxide, the second layer is made of titanium oxide, doped with vanadium oxide as the third layer.

EFFECT: use of the invention ensures safe preparation of a tooth for a crown, minimizing overheating of hard tissues and dental pulp during treatment procedures.

1 cl, 9 dwg

Description

The invention relates to medicine and can be used in orthopedic dentistry for separating the prepared tooth from neighboring teeth during prosthetics under an artificial crown, making one smooth movement from the chewing surface to the interdental papilla.

Analogues

Dental diamond discs are known for processing hard dental tissues for artificial crowns, for teeth separation, and also for grinding fillings (http://library.bashgmu.ru/elibdoc/elib440.pdf).

Their working surfaces are coated with nickel-based diamond powder. Conical discs have a diamond coating on the inner surface and are used for preparing the mesial surfaces of converging teeth. The center holes of the disks serve to secure the disk holder to the screw (https://studfile.net/preview/9765397/page:35/).

Currently, single-sided and double-sided discs with diameters of 16, 20 and 22 mm and conical discs (disc-shaped) with a diameter of 18 mm are produced (https://studfile.net/preview/9765397/page:35/).

The abrasiveness of diamond separation discs traditionally used in dentistry is determined by particles of high-grade diamond chips sprayed onto metal discs in one or several layers.

Criticism of analogues

Working with diamond blades leads to a loss of their cutting properties due to the filling of the spaces between the cutting edges with detritus. In addition, when overheated, the bonding layer is destroyed and diamond particles are lost, forming wear on the multi-layer diamond coating of the tool, which contributes to a sharp decrease in tool life. Further use of such a worn-out disc can also lead to overheating of the hard tissues and pulp of the tooth being prepared for the crown, and as a result, the development of its inflammation or even necrosis.

Another significant disadvantage of the above cutting instruments is the low efficiency associated with the impossibility of reusing them after sterilization by the most widely used in clinical practice, air and glasperlene methods, in which sterilization occurs at a temperature not exceeding 160°C. If sterilization is carried out at temperatures above this value, this can lead to disruption of the structure of the abrasive layer of rotating products (https://dezr.ru/rubriki-izdaniya/latest-articles/86-dezinfektsiya-v-lpu/106-obrabotka-rotatsionnykh -stomatologicheskikh-instramentov).

Thus, the issues of improving the structural and technological properties of a traditional dental diamond separation disc, associated with increasing wear resistance and prolonging its abrasive and cutting properties, as well as reducing their negative impact on tooth tissue (safety) during treatment procedures, remain relevant to this day.

Prototype

The closest in terms of technical solution and achieved result, taken as a prototype, is a cutting tool with a multi-layer coating on the working part, containing a tool base made of hard alloy and a five-layer wear-resistant coating.

RU (11) 2 599 313 (13) S2 (51) MPK S23S 14/06 (2006.01) V23V 27/14 (2006.01) 10.10.2016 Korobeinikov N.V. (RU), Koshkin K.A. (RU) Cutting tool with multi-layer wear-resistant coating - prototype

Criticism of the prototype

The disadvantages of the prototype instrument are the absence of an abrasive diamond layer on the tool base made of hard alloy, which gives the instrument high cutting ability, as well as the impossibility of its use in clinical dental practice. The prototype tool is used in all areas of mechanical engineering related to metal machining.

Purpose of the invention

The purpose of the proposed invention is to increase the wear resistance of a dental diamond separation disc when preparing teeth for artificial crowns.

The problem that the device is aimed at solving is to reduce the wear rate of the multilayer diamond coating of the instrument that occurs during the process of preparing a tooth for a crown, reducing friction forces in the tooth preparation area and minimizing the risk of overheating of hard tissues and tooth pulp.

This task is achieved due to the fact that in the proposed dental diamond separation disc with a wear-resistant nanocoating, which gives it increased wear resistance, a three-layer nanocoating of aluminum oxide and titanium oxide doped with vanadium oxide is applied to the working part of the tool using atomic layer deposition technology.

The essence of the invention

A three-layer nanocoating (total thickness 100 nanometers) consists of: 1 layer - aluminum oxide, which is the substrate and exhibits better adhesion with titanium oxide, 2 layer - titanium oxide doped with vanadium oxide (3 layer) (Fig. 1). The result is a stable multilayer compound with better physical, chemical and mechanical properties.

The essence of the invention is illustrated in Fig. 1, where pos. 1 - layer of aluminum oxide, pos. 2 - layer of titanium oxide, pos. 3 - layer of vanadium oxide.

The appearance of a dental diamond separation disc with a wear-resistant nanocoating is illustrated in Fig. 2.

Examples of use of the proposed invention

Example 1. Experimental protocol

The experimental study was carried out on 78 teeth of 39 outbred male rats aged from 6 months to 1 year and weighing from 180 to 200 grams, kept under the same conditions in the vivarium of the Federal State Budgetary Educational Institution of Higher Education DG'MU of the Ministry of Health of Russia.

When performing all experimental studies, the authors adhered to the “Rules for carrying out work using experimental animals”, reflected in Order No. 755 of the USSR Ministry of Health dated 08/12/1977 “On measures to further improve organizational forms of work using experimental animals”, as well as recommendations for the use of laboratory animals in experiments (I.P. Zapadnyuk, V.I. Zapadnyuk, E.A. Zakaria et al., 1983)).

A comparative histomorphological and electron microscopic study was carried out on the dynamics of the state of the pulp of rat teeth after their standard preparation for artificial crowns using a dental diamond separation disc with a wear-resistant nanocoating and a traditional dental diamond separation disc

In the main group of studies, in the teeth of rats after their standard preparation for artificial crowns using a dental diamond separation disc with a wear-resistant nanocoating, after 1 day a zone of unchanged dentin remained between the pulp and the prepared tooth surface. In the pulp, in the layer of odontoblasts, an increase in their rows was noted, and in the subodontoblastic zone, an increase in “cellularity”. Moderate plethora was observed in the MCR vessels of both coronal and root pulp (Fig. 3). No reactions were detected in periodontal tissues.

Fig. 3. A rat tooth after its standard preparation for an artificial crown using a dental diamond separation disc with a wear-resistant nanocoating 1 day after the experiment.

The pulp is intact. The MCR vessels of both coronal and root pulp are moderately congested. Hematoxylin and eosin staining. X 25.

In the main group, during electron microscopic examination of the dental pulp at this time, the odontoblasts of the coronal pulp were in a functionally active state. Their cytoplasm contained a developed lamellar complex, many mitochondria, lysosomes, and a well-developed cytoplasmic reticulum (Fig. 4).

Fig. 4. A rat tooth after its standard preparation for an artificial crown using a dental diamond separation disc with a wear-resistant nanocoating 1 day after the experiment.

In the cytoplasm of cells in the layer of odontoblasts of the coronal pulp there is hyperplasia of ultrastructures. In the figure: L - lysosome, CPS - cytoplasmic reticulum. Electronogram. X 3300.

On the 180th day from the start of the experiment in the main group of studies in the dental pulp, the rate of cell proliferation in the odontoblast layer and the formation of replacement dentin remained at a high level. There were no signs of inflammation in the coronal pulp; a barely noticeable congestion of the MCR vessels was determined in it (Fig. 5). The root canal pulp and non-riodont were unchanged.

Fig. 5. A rat tooth after its standard preparation for an artificial crown using a dental achmaz separation disc with a wear-resistant nanocoating 180 days after the experiment.

The pulp is intact, without signs of damage. Formation of replacement dentin. Hematoxylin and eosin staining. X 50

In the comparison group, in the teeth of rats after their standard preparation for artificial crowns using a traditional dental diamond separation disc, after 1 day signs of diffuse inflammation with the formation of an infiltrate of lymphocytes, plasma cells and histiocytes were observed in the coronal pulp. Sclerosis of the pulp crown was observed in places. The odontoblast layer was preserved (Fig. 6). The root canal pulp and periodontium were intact.

Fig. 6. A rat tooth after its standard preparation for an artificial crown using a traditional dental diamond separation disc 1 day after the experiment.

Diffuse chronic inflammation with the formation of an infiltrate of lymphocytes, plasma cells and histiocytes. In places there is sclerosis of the pulp crown. The odontoblast layer is preserved. Hematoxylin and eosin staining. X 50.

In an electron microscopic examination of the dental pulp of the comparison group, after 1 day, in the cytoplasm of intact odontoblasts of the coronal pulp, expansion of the cytoplasmic reticulum cisterns, swelling of mitochondria, vacuolization at one of the poles, destruction of cristae and an increase in the number of lysosomes were noted. The boundaries of some cells were unclear (Fig. 7).

Fig. 7. A rat tooth after its standard preparation for an artificial crown using a traditional dental diamond separation disc 1 day after the experiment.

Fragment of odontoblast of the coronal pulp. Expansion of the cisterns of the cytoplasmic reticulum, swelling of mitochondria with destruction of cristae and an increase in the number of lysosomes. Cell boundaries are unclear. In the figure: M - mitochondria, CPS - cytoplasmic reticulum, I - nucleus. Electronogram. X 5950.

On the 180th day from the start of the experiment, pronounced diffuse chronic inflammation with microabscesses and the formation of free and parietal dense formations represented by oeteodentin was found in the coronal pulp of the teeth of the comparison group. As for odontoblastic cells, they were not detected in the coronal pulp at this time of the study. From the side of the arch of the tooth cavity, replacement dentin of moderate thickness was determined in the pulp (Fig. 8). There was no inflammation in the root canal pulp. Moderate vascular congestion and perivascular edema were observed in periodontal tissues.

Fig. 8. A rat tooth after its standard preparation for an artificial crown using a traditional dental diamond separation disc 180 days after the experiment.

In the coronal pulp there is chronic inflammation with microabscesses and the formation of free and parietal formations of osteodentine. Hematoxylin and eosin staining. X 50.

Electron microscopic examination of the dental pulp of the comparison group on the 180th day of observation revealed dystrophic changes in the myelin sheaths of nerve fibers in the central zone of the coronal pulp in the coronal pulp in the form of the formation of myelin figures. In the axoplasm, swelling of mitochondria and destruction of their cristae were observed (Fig. 9).

Fig. 9. A rat tooth after its standard preparation for an artificial crown using a traditional dental diamond separation disc 180 days after the experiment.

Swelling of axoplasmic mitochondria and the appearance of myelin figures in the myelin sheath of the pulpy nerve fiber of the coronal pulp. In the figure: M - mitochondria, MF - myelin figures. Electronogram. X 4800.

Features of the invention that are different from the prototype

1. Difference in purpose: the proposed instrument is a specialized dental instrument for preparing teeth for artificial crowns, in contrast to the prototype instrument, which is used in all areas of mechanical engineering related to the mechanical processing of metals, including light alloys, in particular aluminum.

2. The working part of the proposed tool is made of a nickel base;

3. The surface of the working part of the proposed tool is coated with diamond powder;

4. A three-layer nanocoating with a total thickness of 100 nanometers is applied to the surface of the working part of the proposed tool, coated with diamond powder, using atomic layer deposition technology. It consists of: 1st layer - aluminum oxide, which is the substrate, 2nd layer - titanium oxide, 3rd layer - vanadium oxide, which alloys the 2nd layer;

Technical effect of using the invention

The proposed coating contributes to the long-term preservation of diamond particles and prevents the rapid destruction of the binder layer on the surface of the cutting part of the tools, prolonging their abrasive and cutting properties. The three-layer nanocoating makes it possible for these instruments to be reused many times after sterilization. It also allows for safe tooth preparation for a crown, minimizing overheating of hard tissues and tooth pulp during treatment procedures.

The used wear-resistant nano-coating allows the diamond separation disc to operate for a greater number of cycles in comparison with analogues, ensures its wear resistance and durability due to the stable physical and chemical connection of the constituent components of the working part of the metal nickel-plated blank of the diamond separation disc, and is safe for hard tissues and dental pulp during operation.

Sources of information taken into account:

RU (11) 2 599 313 (13) S2 (51) MPK S23S 14/06 (2006.01) V23V 27/14 (2006.01) 10.10.2016 Korobeinikov N.V. (RU), Koshkin K.A. (RU) Cutting tool with multi-layer wear-resistant coating - prototype

(19) RU (11) 2 725 467 (13) C1 07/02/2020 Oganyan M.G (RU), Vereshchaka A.A. (RU), Sotova E.S. (RU), Bublikov Yu.I. (RU), Lytkin D.N. (RU) (54) Multilayer composite coating for cutting tools for machining titanium alloys under interrupted cutting conditions

(19) RU (11) 2 450 081 (13) C2 05/10/2012 Lechthaler Markus (AT), Reiter Andreas (AT) Wear-resistant hard coating for workpieces and a method for its preparation

(19) RU (11) 2 454 311 (13) C2 06.27.2012 Kim Vladimir Alekseevich (RU), Bashkov Oleg Viktorovich (RU), Khvostikov Alexander Stanislavovich (RU), Sablin Pavel Alekseevich (RU) Method for producing titanium disk with coating titanium carbide

Claims (1)

A dental separation disk for preparing teeth containing a working part on which a multilayer coating is applied, characterized in that a three-layer nanocoating is applied to the working part of the instrument, made of a nickel base, the surface of which is coated with diamond powder, using atomic layer deposition technology, the total thickness of which is is 100 nanometers, while the first coating layer, which is the substrate, is made of aluminum oxide, the second layer is made of titanium oxide doped with vanadium oxide - the third layer.