RU2503067C1 - Method for simulating enamel demineralisation centre - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: dental bracket is fixed onto an extracted tooth. A centre surrounding the dental bracket on a vestibular surface is limited by a wax layer. The tooth is immersed into a separated container with a demineralising gel consisting of (wt %): calcium dihydrophosphate - 0.04-0.08, lactic acid - 0.8-1.0, praestol 2510 - 3.0-4.5, sodium hydroxide - 0.4, distilled water - the rest. Then, the container with the teeth is placed in a thermostat at pH=4.5 for 96 hours.

EFFECT: more sharp demineralisation centre.

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Description

The invention relates to medicine, namely to experimental dentistry, can be used to simulate the focus of demineralization of tooth enamel in order to develop methods for treating initial caries.

A known method of obtaining a focus of demineralization by immersing teeth in a demineralizing gel (Peter Gangler, Thomas Kreminczky. In vitro effect of fluoride oral hygiene tablets on artificial caries lesion formation and remineralization in human enamel, BMC Oral Health, 2009).

In this method, the crown and root, removed according to the testimony of third human molars, are covered with red wax, and enamel windows 3-4 mm in size are left on the buccal and lingual (palatal) surfaces, then the teeth are immersed in a demineralizing gel for 72 hours at a constant temperature 37 ° C. The gel contains: 1.5 mM calcium chloride, 0.9 mM potassium dihydrogen phosphate, 150 mM potassium chloride, 0.1 M sodium acetate buffer, 30 mM acetate in hydroxyethyl cellulose, pH = 4.7.

The disadvantage of this method is the lack of clarity of the results due to the visual determination of the size of the enamel windows, the interaction of color dyes of wax with components of the demineralizing gel.

Effect: increasing the clarity of the focus of demineralization. The specified technical result is achieved by the fact that in the method of modeling the demineralization site, a tooth is used, a bracket is fixed on the surface, the tooth root, palatine, aproximal and part of the vestibular surface are waxed (for example, Stoma, Ukraine), a lesion of at least 2 mm , which is located around the bracket and repeats its shape. After that, each tooth is immersed in an individual container with 10.0 ml of demineralizing gel, weight in%: 0.04-0.08 calcium dihydrogen phosphate, 0.8-1.0 lactic acid, 3.0-4.5 praestol 2510 (polyacrylamide with a molecular weight of about 14 million units), hydroxide solution sodium 0.4, the rest is distilled water. Next, a container with a tooth is placed in a thermostat for 96 hours, at a temperature of 37 ° C, at pH = 4.5.

The method is illustrated by drawings, in which Fig. 1 shows a longitudinal section of a tooth when examined in an electron scanning microscope (Evex Mini-SEM HR-3000, accelerating voltage of 30 kV, magnification 100, example 1); figure 2 shows a longitudinal section of the same tooth when examined in an electronic scanning microscope (Evex Mini-SEM HR-3000, accelerating voltage of 30 kV, magnification 500, example 1); figure 3 shows a longitudinal section of another tooth when examined in an electronic scanning microscope (Evex Mini-SEM HR-3000, accelerating voltage of 30 kW, magnification 100, example 2); figure 4 shows a longitudinal section of the same tooth when examined in an electronic scanning microscope (Evex Mini-SEM HR-3000, accelerating voltage of 30 kV, magnification 150, example 2).

The method is as follows.

In order to preserve the tooth as an object of study, sparing removal is carried out, trying to prevent violation of the integrity of the surface layer of enamel. After removal, the tooth is washed with running water, freed from soft tissues and immersed in a 0.9% isotonic sodium chloride solution at room temperature. Further, the entire tooth is covered with light yellow orthopedic wax (for example, Stoma, Ukraine) with the exception of a square on the vestibular surface, at least 2 mm wide, located on the periphery of the bracket. In the root of the tooth with a diamond bur in a dental unit (Chirana-Dental, Slovakia), under water cooling, a hole is prepared through which a polyethylene line is threaded and the tooth is suspended in an individual container to create a focus of demineralization. The capacity is a vessel made of refractory clear glass. The amount of demineralizing gel in the container is 10.0 ml. It consists of, weight in%: 0.04-0.08 calcium dihydrogen phosphate, 0.8-1.0 lactic acid, 3.0-4.5 praestol 2510 (polyacrylamide with a molecular weight of about 14 million units), sodium hydroxide solution 0.4, the rest is distilled water. After that, the container with the tooth is placed in a thermostat at a temperature of 37 ° C for 96 hours, pH = 4.5. After 96 hours, the tooth is removed from the demineralizing gel, washed in distilled water, freed from wax and prepared for microscopic examination methods.

A study was conducted of 12 teeth (7 canines of the upper jaw, 5 incisors of the upper and lower jaw), removed according to indications.

Example 1

The object of the study was the central incisor of the upper jaw, removed according to indications. A bracket is fixed to the tooth, all surfaces are isolated with wax, with the exception of the rectangular area around the bracket, the width of which is at least 2 mm. A hole for acid-resistant fishing line is formed in the root of the tooth. 10.0 ml of demineralizing gel is prepared: 0.02 g of calcium dihydrogen phosphate, 0.40 g of lactic acid, 1.50 g of praestol 2510, 0.4% sodium hydroxide solution. Immerse the tooth in an individual container with gel, put in a thermostat at 37 ° C, pH = 4.5. After 96 hours, the tooth is extracted, washed in distilled water, cleaned of wax, the bracket is removed, a longitudinal section of the preparation is prepared for examination in an electronic scanning microscope (ESM, Evex Mini-SEM HR-3000, accelerating voltage of 30 kV). When studying in the ESM, images of hard tissues of the tooth and the focus of demineralization were obtained. With a 100-fold increase, the area of the demineralization focus has the shape of a triangle, the base of which is facing the tooth enamel, and the tip is towards the enamel-dentin border (Fig. 1). At a maximum increase (500 times) in the area of the focus of demineralization, a violation of the clear structural arrangement of enamel prisms and interprismatic substance is determined, pores and loosening areas appear (Fig. 2).

Example 2

The object of the study was the canine of the upper jaw, removed according to indications. A bracket is fixed to the tooth, all surfaces are isolated with wax, with the exception of the rectangular area around the bracket, the width of which is at least 2 mm. A hole for acid-resistant fishing line is formed in the root of the tooth. 10.0 ml of demineralizing gel is prepared: 0.04 g of calcium dihydrogen phosphate, 0.50 g of lactic acid, 2.25 g of praestol 2510, 0.4% sodium hydroxide solution. Immerse the tooth in an individual container with gel, put in a thermostat at 37 ° C, pH = 4.5. After 96 hours, the tooth is extracted, washed in distilled water, cleaned of wax, the bracket is removed, a longitudinal section of the tooth is prepared for examination in an electronic scanning microscope (ESM, Evex Mini-SEM HR-3000, accelerating voltage of 30 kV). When studying in the ESM, images of hard tissues of the tooth and the focus of demineralization were obtained. When you increase 100 times the area of the focus of demineralization has the shape of a triangle, the base of which is facing the tooth enamel, and the top is towards the enamel-dentin border (Fig. 3). At a maximum increase (150 times) in the area of the focus of demineralization, there are areas with a significant number of pores and a disordered structure, deep pits appear, the ultrastructure of enamel prisms and interprismatic substance changes (Fig. 4).

Claims (1)

The method of modeling the focus of demineralization of tooth enamel by immersing a tooth in a container with demineralizing gel, where the focus of demineralization, located on the vestibular surface of the tooth, is limited by a wax coating, followed by placing the container with the tooth in a thermostat at t = 37 ° C, characterized in that it is remote the tooth is fixed with a bracket, immersed in an individual container with a demineralizing gel, consisting of, wt.%:
calcium dihydrogen phosphate 0.04-0.08 lactic acid 0.8-1.0 praestol 2510 3.0-4.5 sodium hydroxide solution 0.4 distilled water rest
then the tooth container is placed in a thermostat at pH 4.5 for 96 hours.

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