The concept of permeability of mineralization of enamel demineralization. Lecture: Permeability of tooth enamel and the process of its maturation

Teeth are living organs with constant processes occurring in them. metabolic processes. Many people have probably heard more than once about such a phenomenon as the acid-base balance, which must be restored every time after eating. This is explained by the fact that in oral cavity After eating, the pH becomes acidic. To neutralize this condition, the process of “washing out” microelements from tooth enamel into the oral cavity begins to become more active. This process is called demineralization; if it becomes dominant over the processes of remineralization, then defects appear in the enamel, which subsequently open the way for the development of caries.

This is a pathological process in which the hard tissues teeth with accompanying demineralization. A cavity gradually forms in the tooth. The development of caries can be influenced by external and internal reasons. It is characterized by the following stages:

• Stains.
• Surface.
• Average.
• Deep.

When a violation of the enamel is in the staining stage, this can be easily noticed by its lost color - it becomes dull with the loss of its characteristic shine. In this case, there is no roughness on the surface - it is absolutely smooth. At this stage, caries is practically invisible, so in order to identify its early form, the methylene blue staining method is used. First you need to remove plaque from the enamel, for which you use a thick swab treated with hydrogen peroxide. If there is an initial manifestation, then this area of ​​enamel treated with dye, due to increased permeability, will turn blue. And accordingly, the white spot, which is not of carious origin, will remain unchanged.

When caries is detected, the white spot stage must be treated. This therapy consists of the following:

• A diet is prescribed that is rich in vitamins, proteins, mineral salts and other useful and necessary substances.
• Remineralizing therapy is carried out, which is based on the use of products containing sufficient amounts of calcium and fluoride.

Currently in dentistry great attention takes an integrated approach to the treatment of dental caries. If earlier the emphasis was mainly placed only on filling and improving methods for eliminating carious cavities, now it is no less important to influence the factors and other circumstances of its formation. Research has found that main reason The formation of caries is caused by the presence of a specific “streptococcus mutans”. This microorganism is capable of releasing acids during its life processes, which provoke the process of tooth enamel losing mineral substances. As a result, demineralization leads to the formation of caries. To prevent such complications, teeth are remineralized.

This treatment method consists of filling tooth enamel with essential minerals. Since the main elements of the structure of teeth include phosphorus and calcium, they form the basis of remineralizing compounds. In this case, fluorine influences the formation of acid-resistant forms of the main substance of tooth enamel - apatite.

To increase the effectiveness of the procedure, it is combined with the use of fluoride-containing products. In most cases, fluorides are recommended after completing a remineralization course to reduce the release of calcium from tooth enamel. Drugs intended for therapy are produced in different forms, these can be varnishes, gels, special pastes. Solutions of mineral substances are also used in the form of applications to the points of problem teeth and calcium preparations for internal use.

Based on the above, we can come to the conclusion that remineralization therapy is the process of professional treatment of enamel with special preparations that aim to normalize its mineral composition. It helps get rid of small defects that were caused by demineralization, in addition, it serves as a strong prophylactic agent that prevents damage to the enamel as a result of leaching of calcium and phosphorus from hard dental tissues.

Why is remineralization needed?

In the oral cavity, the process of formation of certain chemical reactions, the pH level changes; the presence of various microorganisms that lead their lives in dental plaque also contribute to the overall picture. The appearance of dental plaque, a lack of minerals that enter the patient’s body with food, and disturbances in the acid-base balance often provoke the process of the enamel releasing the components it needs, in particular minerals. All this ultimately leads to the beginning of demineralization, as a result of which the enamel gradually becomes thinner and thinner, forming a carious cavity.

At the same time, this process is quite lengthy, and the tooth is destroyed due to the process not starting immediately. First, demineralized lesions form - the color and structure of the enamel changes, making it much more vulnerable to activating caries. And it should be noted that this stage of the so-called white spot of the carious process may well be reversible.

But for this it is necessary to timely saturate the enamel with important elements such as calcium, phosphorus and fluorine. For this purpose, there is a procedure called remineralization. Using this method, you can not only completely restore the enamel, but also reduce the susceptibility of teeth to caries. The benefits of remineralization therapy are outlined in the list below:

• Provides protection of teeth from caries as an excellent preventive procedure.
• It is highly effective at the onset of caries development, contributing to the preservation of teeth; cures caries without the use of mechanical interventions.
• Excellent in eliminating hypersensitivity, as it is a consequence of dental demineralization.
• Helps replenish the loss of minerals in tooth enamel as a result of the whitening procedure. It also increases the content of minerals lost during the treatment of orthodontic diseases, in adolescence, when they are intensively consumed during the active growth of the patient, pregnancy due to the high need of the fetus for minerals.

Indications for the procedure

Remotherapy is a kind of urgent help in dental practice, which returns wasted minerals to the teeth and preserves the normal condition of the teeth, making them more resistant to negative impacts and other undesirable factors. Currently, there are certain indications for this therapy:

• With increased sensitivity of tooth enamel.
• Initial caries, the so-called “white spot” stage.
• For minor multiple carious formations.
• Lesions of tooth enamel of a non-carious nature, expressed by fluorosis, enamel hypoplasia, wedge-shaped defect and some others.
• The patient suffers from pathological tooth wear.
• As a consolidating procedure after sessions to remove plaque and tartar.
• After whitening, during the treatment of orthodontic diseases and upon its completion, during breastfeeding and some other procedures and conditions in order to replenish the mineral composition of the enamel.

Enamel permeability: what is it?

Research in this area shows that the level of permeability of tooth enamel can be influenced by a number of factors, for example, the following:

• Age. It should be noted that this indicator does not increase with age, but rather decreases.
• Application of electrophoresis.
• Ultrasonic waves help increase the permeability of tooth enamel.
• A significant factor for permeability is low pH.
• Hyaluronidase enzyme. The permeability of the enamel increases under its influence, the amount of which, in turn, becomes greater in the oral cavity in the presence of dental plaque and microorganisms developing in it.
• Sucrose. Permeability becomes more pronounced if sucrose is added to the microorganisms in dental plaque.

A few words need to be said about some elements that play an important role in the processes of remineralization. Thus, the flow of ions into tooth enamel is highly influenced by the characteristics of the ions. For example, divalent ions have less penetrating power than monovalent ions. Of great importance in this is also the charge of the ion, pH of the environment and enzyme activity. At the same time, special attention is required to study how fluoride ions distribute in tooth enamel. When applied, a solution of sodium fluoride allows fluoride ions to quickly reach a small depth and, according to some researchers, be incorporated into the crystal lattice. It is necessary to note that the surface of tooth enamel treated with such a solution becomes low permeable.

Technology

This procedure is considered completely painless and does not require any special effort or time. And the effect of its use is always very high. And you can be sure that the teeth of both adults and children will be kept healthy and beautiful. There are several methods of remineralization; each method may have its own procedure. At the same time, there are also moments that are characteristic of all. Below is only general methodology, but it gives a clear idea of ​​how this should all happen:

• The procedure is performed only on absolutely clean tooth enamel.
• If there are indications, it is carried out with mandatory professional sanitation of the oral cavity.
• Remineralizing therapy sessions are individually selected for each patient.
• Selecting a suitable gel
• A soft tray special for this procedure is selected and the gel is introduced into it.
• A mouthguard with gel is installed in the oral cavity on prepared (air-dried) teeth.
• Apply the gel for four minutes. After completing the procedure, it is not recommended to eat, rinse, or drink for an hour. It is advisable to carry out these procedures at least once a year, and preferably twice.

Remineralization in children

Initial caries includes two forms: in the spot stage and superficial. In the first case, the child develops white, chalky-colored spots on his teeth (in most cases, the upper incisors). different shapes and magnitude. There is usually no pain in this case. Spots that do not initially have any defined boundaries begin to grow steadily over time and ultimately lead to the formation of carious cavities. This will already be the stage of superficial caries.

In some cases, its occurrence and the appearance of a carious cavity can be determined by the formation of spots of roughness on the surface, while tooth enamel becomes softer and can be removed using a tool. For the most part, the little patient does not experience pain, however, in some cases this phenomenon may be characterized by increased sensitivity to cold and hot food, as well as to other irritants.

Using remineralization, introducing the missing mineral components, as a rule, a combination of the main three minerals, it is possible to achieve (although, admittedly, this does not happen often) the disappearance of the stain, or to stop the demineralization process that has begun.

For remineralization, the following drugs and solutions are used:

• calcium gluconate (10 percent);
• Remodenta (3 percent), which does not contain fluorine;
• acidified calcium phosphate (2 and 10 percent solutions);
• sodium fluoride (2 percent);
• gel (one percent) containing fluoride;
• gel (with pH 6.5-7.5 and 5.5) containing calcium and phosphate.

It also includes:

• Diplene F – dental adhesive film. It must be glued to the baby’s tooth before bedtime, after brushing the teeth. Overnight, the film will completely dissolve, and fluoride ions will take their place in the crystal lattice of tooth enamel.
• Fluoride varnish. When applying it, you must adhere to food intake restrictions for at least three hours.

It is very important that during remineralization therapy the child follows daily hygiene oral cavity, brushed teeth at least twice a day and ate as little sweets as possible. Quite often, especially when in young patients the tooth enamel is not yet sufficiently mineralized, the remineralizing procedure turns out to be timely and effective. It makes it possible to slow down the onset of caries development. Six months later, you can already notice how the tissues have thickened.

Application methods

Due to the weak genesis of hard dental tissues, which usually occurs during intrauterine development Due to the influence of negative factors on the mother’s body and child, erupting teeth no longer have the optimal mineral composition in the enamel. Therefore, there is a need to carry out active remineralization in order to prevent caries.

When treating temporary teeth, a fairly popular method of silvering with 30% AqNO3 can be used. The procedure gives very good results in most cases. It is recommended to carry out treatment in three sessions with day breaks, then repeat the procedure after three months and after six.

Remineralizing therapy uses the Borovsky-Leus method. It includes five-minute applications (two or three times) of 10 percent calcium gluconate, then three minutes of two percent sodium fluoride. The procedures are performed until the focal spots disappear. The course of treatment continues, taking into account the activity of dental caries, usually for ten days. It is recommended that children with initial stages of caries undergo this therapy at least twice a year, but if stage 3 is observed, every three months.

Studies conducted over a number of years have shown that the use of this method gives good results and significantly reduces the percentage of caries.

Method of T. Vinogradova:

• Apply a solution of calcium gluconate (10 percent) for three minutes.
• Rinse or bathe the mouth with a sodium fluoride solution for one or two minutes, or coat the tooth enamel with fluoride varnish as an alternative.

P. Leus method:

• Using electrophoresis with calcium gluconate (10 percent) for three to five minutes.
• Application of an application with a 2 percent sodium fluoride solution for two minutes. The course of treatment is three times with weekly breaks.

The drug includes the following composition (percentages in brackets):

• calcium (4.4), phosphorus (1.4);
• magnesium (0.15), potassium (0.20);
• sodium (6.0), chlorine (30.0);
• organic matter (44,0);
• microelements (up to 100).

Remodent is usually used for rinsing procedures, applications (3 percentage solution), for cleaning with toothpaste, which contains three percent of the drug by weight.

Before using the application, you need to brush your teeth well with an oral hygiene paste, after which tampons treated with remodent are applied for a quarter of an hour. During the year, experts advise carrying out three to five procedures. After each session, you should not eat or brush your teeth for two hours. Use 10 ml of solution as a rinse (lasting up to five minutes).

The effectiveness of the drug as a prophylactic agent can reach 50 percent. The effectiveness is most pronounced on chewing surfaces.

Gel for teeth

Remineralization therapy is an effective and physiological way to treat and prevent caries. There is an excellent gel R.O.C.S. Medicals Minerals, which will strengthen teeth with minerals using a mouth guard. It will also improve the shine and color of teeth without the help of aggressive whitening agents, this is especially important for those patients who are contraindicated for teeth whitening. Features of the composition:

• is a source of highly digestible compounds of magnesium, calcium and phosphorus;
• special additives give it adhesive properties;
• forms an invisible film on the enamel;
• promotes active gradual penetration into dental tissues;
• the presence of xylitol increases its remineralizing effect

Finally

Summarizing the above, we can come to the conclusion that remineralizing therapy is really effective method to prevent caries in the initial stages. It is able to compensate for the loss of minerals from tooth enamel and bring their saturation to an optimal level. This will significantly increase the resistance of tooth enamel to various acids. In addition, this method is completely painless, which is aimed at ensuring that teeth are always beautiful and healthy.

Remineralizing therapy is usually carried out in courses of treatment. Depending on the condition of the teeth, the specialist will prescribe the required annual number of procedures. It can be performed on both adult patients and children. The technique of application is that the patient applies special pastes and varnishes to the entire dentition.

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Size and charge of ions (single-charged ones penetrate better than doubly-charged ones)

Ion concentration gradient (only those ions penetrate, the concentration of which in the oral fluid is greater than in the enamel fluid)

Enamel permeability

Enamel permeability- this is the ability of enamel to pass water and mineral and organic substances dissolved in it in two directions: from the surface of the enamel to the dentin and vice versa.

The mechanisms of enamel permeability to inorganic ions and organic substances contained in oral fluid are different.

Permeability to inorganic ions. The enamel has microspaces between the prisms and inside the prisms, filled with enamel liquid. The mechanism of entry of ions from the oral fluid into the enamel fluid along a concentration gradient by simple diffusion. The speed and depth of penetration of ions into the enamel fluid depends on:

3) the ability of ions to bind to the components of the enamel and enter the crystal lattice of HA (well-adsorbed ones - slowly diffuse into the deep layers of the enamel, and those that interact poorly with HA - quickly diffuse to the pulp and from it into the blood).

Permeability to organic substances. Low molecular weight organic substances, such as amino acids and glucose, pass through the enamel in transit into dentin through lamellae - formations of an organic nature. Such substances do not participate in the exchange of enamel.

1. Degree of enamel mineralization - calcium and phosphorus content in enamel. The more mineralized the enamel, the less permeable it is. This is due to the fact that as HA crystals grow and the packing density of the crystals increases, the layer of enamel liquid surrounding the crystals decreases. This creates a mechanical barrier to the penetration of water-soluble substances.

Demineralization of enamel during pathological processes, for example, at a certain stage of caries development, increases the permeability of enamel.

2. Pellicle- an organic film on the teeth prevents the entry of substances into the enamel.

3 .Availability defects in enamels, for example, microcracks increase the permeability of enamel.

4.Physical factors (ultrasound, electrophoresis) increase permeability.

Events after the passage of ions into the enamel fluid

1 .Accumulation on the surface of HA crystals. Some of the penetrating ions accumulate in the hydration shell surrounding the HA crystal. Accumulation occurs within a few minutes after the ions enter the enamel. The accumulation is due to the surface charge of HA crystals. The charge arises due to the presence of “defects” in the crystal lattice. Theoretically, the composition of HA is expressed by the formula Ca 10 (PO 4) 6 (OH) 2; it corresponds to a Ca/P ratio of 1.67. In reality, this ratio is in the range of 1.33 -2.0, that is, in reality the composition of HA differs from the theoretical one. For example, there may be octalcium apatite. In the place of the crystal lattice where such apatite is present there is a negative charge. 16+ [(PO 4) 6 (OH) 2 ] 20-

2. Penetration of ions into the crystal. Some of the accumulated ions can enter the hydration shell and leave it. However, other ions are able to penetrate the surface of the crystal. Penetration depends on the nature, size, and charge of the ion. For example, ions such as Ca 2+, Sg 2+, Mg 2+, Ba 2+, HPO 4 2-, F -, H + penetrate. Penetration occurs within a few hours.

3.Introduction of ions into the HA crystal lattice (intracrystalline exchange). It goes on for many months. The introduction of HA into the crystal lattice occurs according to the principle of charge compensation two ways.

1). Occupation of vacant sites in the lattice by an ion. For example, calcium, magnesium and other cations can be incorporated into octalcium HA to compensate for the excess negative charge.

Biochemistry of hard dental tissues

Such fabrics include enamel, dentin, dental cement. These tissues differ from each other by their different origins in ontogenesis. Therefore, they differ in chemical structure and composition. And also by the nature of metabolism. In them, the enamel is of eptodermal origin, and the bone, cement, and dentin are of mesentimal origin, but despite this, all these tissues have much in common and consist of intercellular substance or a matrix of carbohydrate-protein nature and a large amount of minerals, mainly represented by apatite crystals.

Degree of mineralization:

Enamel -> dentin -> cement -> bone.

These tissues contain the following percentages:

Minerals: Enamel-95%; Dentin-70%; Cement-50%; Bone-45%

Organic substances: Enamel-1 – 1.5%; Dentin-20%; Cement-27%; Bone-30%

Water: Enamel-30%; Dentin-4%; Cement-13%; Bone-25%.

These crystals have a hexogenal shape.

Mineral components of enamel

They are presented in the form of compounds having a crystal lattice

A(BO)K

A = Ca, Ba, cadmium, strontium

B = PO, Si, As, CO.

K = OH, Br, J, Cl.

1) hydroxyapatite - Ca (PO) (OH) in tooth enamel 75% HAP - the most common in mineralized tissues

2) carbonate apatite - CAP - 19% Ca (PO) CO - soft, easily soluble in weak acids, whole, easily destroyed

3) chlorapatite Ca (PO) Cl 4.4% soft

4) strontium apatite (SAP) Ca Sr (PO) - 0.9% is not common in mineral tissues and is common in inanimate nature.

Min. ingredients 1 – 2% in non-apatite form, in the form of calcium phosphate, dicalciferate, orthocalciphosphate. The Ca/P ratio – 1.67 corresponds to the ideal ratio, but Ca ions can be replaced with similar properties chemical elements Ba, Cr, Mg. At the same time, the ratio of Ca to P decreases, it decreases to 1.33%, the properties of this apatite change, and the resistance of the enamel to adverse conditions decreases. As a result of the replacement of hydroxyl groups with fluorine, fluorapatite is formed, which is superior in both strength and acid resistance to HAP.

Ca (PO) (OH) + F = Ca (PO) FOH hydroxyfluorapatite

Ca (PO) (OH) + 2F = Ca (PO) F fluorapatite

Ca (PO) (OH) + 20F = 10CaF + 6PO + 2OH Ca fluoride.

CaF - it is durable, hard, and easily leached. If the pH shifts to the alkaline side, tooth enamel destruction, enamel mottling, and fluorosis occurs.

Strontium apatite - in the bones and teeth of animals and people living in regions with a high content of radioactive strontium, they have increased fragility. Bones and teeth become brittle, strontium rickets develops, causeless, multiple bone fractures. Unlike ordinary rickets, strontium rickets is not treated with vitamin D.

Features of the crystal structure

The most typical is the hexogenal form of HAp, but there may be rod-shaped, acicular, or diamond-shaped crystals. All of them are ordered, of a certain shape, have ordered enamel prisms - this is the structural unit of enamel.

4 structures:

a crystal consists of elementary units or cells; there can be up to 2 thousand such cells. Mol.mass = 1000. A cell is a 1st order structure, the crystal itself has Mr = 2,000,000, it has 2,000 cells. Crystal is a 2nd order structure.

Enamel prisms are a 3rd order structure. In turn, enamel prisms are collected in bundles, this is a 4th order structure, around each crystal there is a hydration shell, any penetration of substances onto the surface or inside the crystal is bound in this hydration shell.

It is a layer of water associated with a crystal in which ion exchange occurs, it ensures the constancy of the enamel composition, called enamel lymph.

Water is intracrystalline; the physiological properties of enamel and some Chemical properties, solubility, permeability.

Type: water bound to enamel proteins. In the structure of HAP, the Ca/P ratio is 1.67. But there are HAPs in which this ratio ranges from 1.33 to 2.

Ca ions in HAP can be replaced by other chemical elements similar in properties to Ca. These are Ba, Mg, Sr, less often Na, K, Mg, Zn, HO ion. Such substitutions are called isomorphic, as a result the Ca / P ratio decreases. Thus, it is formed from HAP - HFA.

Phosphates can be replaced by the PO ion HPO citrate.

Hydroxites are replaced by Cl, Br, F, J.

Such isomorphic substitutions lead to changes in the properties of apatites - the resistance of enamel to acids and to caries decreases.

There are other reasons changes in the composition of HAP, the presence of vacant places in the crystal lattice, which must be replaced with one of the ions, vacant places arise most often under the action of acids, already in the formed HAP crystal, the formation of vacant places leads to a change in the properties of the enamel, permeability, solubility, adsorb.st.va.

The balance between the process of de- and remineralization is disrupted. Optimal conditions for chemicals arise. reactions on the enamel surface.

Physicochemical properties of apatite crystal

One of the most important properties of a crystal is charge. If there are 10 remaining Ca in a HAP crystal, then consider 2 x 10 = 3 x 6 + 1 x 2 = 20 + 20 = 0.

HAP is electrically neutral; if the HAP structure contains 8 Ca – Ca (PO) ions, then 2 x 8 20 = 16< 20, кристалл приобретает отриц.заряд. Он может и положительно заряжаться. Такие кристаллы становятся неустойчивыми. Они обладают реакционной способностью, возникает поверхностная электрохимическая неуравновешенность. ионы находятся в гидратной оболочке. Могут нейтрализовать заряд на поверхности апатита и такой кристалл снова приобретает устойчивость.

Stages of penetration of substances into a HAP crystal

3 stages

1) ion exchange between the solution that washes the crystal - this is saliva and dental fluid with its hydration shell. It receives ions that neutralize the charge of the crystal: Ca, Sr, Co, PO, and citrate. Some ions can accumulate and also easily leave without penetrating into the crystal - these are K and Cl ions, other ions penetrate into the surface layer of the crystal - these are Na and F ions. The stage occurs quickly within a few minutes.

2) this is an ion exchange between the hydration shell and the surface of the crystal; an ion is separated from the crystal surface and replaced with other ions from the hydration shell. As a result, the surface charge of the crystal is reduced or neutralized and it becomes stable. Longer than stage 1. During few hours. Ca, F, Co, Sr, Na, P penetrate.

3) Penetration of ions from the surface into the crystal - called intracrystalline exchange, occurs very slowly and as the ion penetrates, the speed of this stage slows down. The ions Pa, F, Ca, Sr have this ability.

Availability of vacancies in the crystal lattice is an important factor in the activation of isomorphic substitutions within the crystal. The penetration of ions into the crystal depends on the R ion and the level of E it possesses; therefore, H ions and those close in structure to the H ion penetrate more easily. The stage lasts for days, weeks, months. The composition of the HAp crystal and their properties are constantly changing and depend on the ionic composition of the liquid that washes the crystal and the composition of the hydration shell. These holy crystals make it possible to purposefully change the composition of hard tooth tissues under the influence of remineralizing solutions for the purpose of preventing or treating caries.

Organic substances of enamel

The share of organic matter 1 is 1.5%. In immature enamel up to 20%. Organic elements of enamel affect biochemical and physical processes, occurring in the tooth enamel. Org.v-va nah-xia between apatite crystals in the form of bundles, plates or spirals. The main representatives are proteins, carbohydrates, lipids, nitrogen-containing substances (urea, peptides, cyclic AMP, cyclic amino acids).

Proteins and carbohydrates are part of the organic matrix. All remineralization processes occur on the basis of a protein matrix. Most of it is represented by collagen proteins. They have the ability to initiate remineralization.

1. a) enamel proteins – insoluble in acids, 0.9% EDTA. They belong to collagen- and ceramide-like proteins with a large amount of sulfur, hydroxyproline, gly, and lys. These proteins play a protective role in the process of demineralization. It is no coincidence that in the focus of demineralization at the stage of a white or pigmented spot, the number of these proteins is > 4 times. Therefore, a carious spot does not turn into a carious cavity for several years, and sometimes caries does not develop at all. In older people, caries > resistance. b) calcium-binding proteins of enamel. KSBE. They contain Ca ions in a neutral and slightly alkaline environment and promote the penetration of Ca from saliva into the tooth and back. Proteins A and B account for 0.9% of the total mass of enamel.

2. B. soluble in water, not associated with mineral substances. They do not have an affinity for the mineral components of enamel and cannot form complexes. There are 0.3% of such proteins.

3. Free peptides and individual amino acids, such as promine, gly, val, hydroxyproline, ser. Up to 0.1%

1) protective function. Proteins surround the crystal. Prevents the process of demineralization

2) proteins initiate mineralization. Actively participate in this process

3) provide mineral exchange in enamel and other hard tissues of the tooth.

Carbohydrates are presented polysaccharides: glucose, galactose, fructose, glycogen. Disaccharides are in free form, and protein complexes are formed - phospho-glycoproteins.

There are very few lipids. Presented in the form of glycophospholipids. During the formation of the matrix, they act as connecting bridges between proteins and minerals.

Dentin is inferior in hardness. The most important elements of dentin are the ions Ca, PO, Co, Mg, F. Mg is 3 times more than in enamel. The concentration of Na and Cl increases in the inner layers of dentin.

The main substance of dentin consists of HAP. But unlike enamel, dentin is penetrated by a large number of dentinal tubules. Pain sensations are transmitted through nerve receptors. The dentinal tubules contain processes of odontoblast cells, pulp and dentinal fluid. Dentin makes up the bulk of the tooth, but is less mineralized than enamel; its structure resembles coarse-fibered bone, but is harder.

Organic matter

Proteins, lipids, carbohydrates, ...

Protein matrix of dentin - 20% of the total mass of dentin. Consists of collagen, it accounts for 35% of all organic dentin. This property is characteristic of lysine tissues of normal origin; it contains glucosaminoglycogens, galactose, hexasamites and heliuronic acids. Dentin is rich in active regulatory proteins that regulate the remineralization process. Such special proteins include amelogenins, enamelins, and phosphoproteins. Dentin, like enamel, is characterized by a slow exchange of minimal components, which is of great importance for maintaining tissue stability under conditions of increased risk of demineralization and stress.

Tooth cement

Covers the entire tooth with a thin layer. Primary cement is formed by a mineral substance in which collagen fibers and cellular elements - cementoblasts - pass in different directions. The cement of a mature tooth is little renewed. Composition: mineral components are mainly represented by Ca carbonates and phosphates. Cementum does not have, like enamel and dentin, its own blood vessels. In the apex of the tooth there is cellular cement, the main part is acellular cement. Cellular resembles bone, and acellular consists of collated fibers and an amorphous substance that glues these fibers together.

Dental pulp

This is loose connective tissue of the tooth, filling the coronal cavity and root canal of the tooth with a large number of nerves and blood vessels; the pulp contains collagen, but no elastic fibers; there are cellular elements represented by odontoblasts, macrophages and fibroblasts. The pulp is a biological barrier that protects the dental cavity and periodontium from infection, and performs a plastic and trophic function. It is characterized by increased activity of redox processes, and therefore high oxygen consumption. Regulation of the energy balance of the pulp is carried out by coupling oxidation with phosphorylation. A high level of biological processes in the pulp is indicated by the presence of processes such as PPP, synthesis of RNA, proteins, therefore the pulp is rich in enzymes that carry out these processes, but carbohydrate metabolism is especially characteristic of the pulp. There are enzymes of glycolysis, TCA cycle, water-mineral metabolism (alkaline and acid phosphotose), transaminases, aminopeptidases.

As a result of these metabolic processes, many intermediate products are produced that come from the pulp into the hard tissues of the tooth. All this ensures a high level of ...., reactivity and protective mechanisms.

With pathology, the activity of these enzymes increases. With caries, destructive changes occur in odontoblasts, destruction of collagen fibers, hemorrhages appear, enzyme activity changes, and exchange of substances in the pulp changes.

Routes of entry of substances into hard tooth tissues and enamel permeability

The tooth has contact with mixed saliva, on the other hand - .... blood, the composition of the hard tissues of the tooth depends on their composition. The main part of the organic and mineral substances that enter the tooth enamel is contained in saliva. Saliva acts on tooth enamel and causes swelling or shrinkage of collagen barriers. As a result, a change in the permeability of the enamel occurs. Substances of saliva exchange with substances of enamel and the processes of de- and remineralization are based on this. Enamel is a semi-permeable membrane. It is easily permeable to H O, ions (phosphates, bicarbonates, chlorides, fluorides, cations Ca, Mg, K, Na, F, Ag, etc.). They determine the normal composition of tooth enamel. Permeability also depends on other factors: on the chemical structure of the substance and the strength of the ion. The sizes of apatites are from 0.13 - 0.20 nm, the distance between them is 0.25 nm. Any ions must penetrate the enamel, but determine the permeability with t.zr. Mr or ion sizes are not possible; there are other properties of the ion’s affinity for enamel hydroxyapatite.

The main route of entry of substances into the enamel is simple and facilitated diffusion.

The permeability of enamel depends on:

1) sizes of microspaces, filled. H O in the enamel structure

2) the size of the ion or the size of the molecule of the substance

3) the ability of these ions or molecules to bind to enamel components.

For example, the F ion (0.13 nm) easily penetrates the enamel and binds to the enamel elements in the damaged enamel layer, therefore it does not penetrate into the deeper layers. Ca (0.18 nm) – is adsorbed on the surface of enamel crystals, and also easily enters the crystal lattice, so Ca is deposited both in the surface layer and diffuses inside. J easily penetrate into the microspace of the enamel, but are not able to bind to HAP crystals, enter dentin, pulp, then into the blood and are deposited in thyroid gland and adrenal glands.

Enamel permeability decreases under the influence of chemical Factors: KCl, KNO, fluoride compounds. F interacts with HAp crystals, creating a barrier to the deep penetration of many ions and substances. The properties of the pron depend on the composition of the mixed saliva. Thus, secret saliva has different effects on the permeability of enamel. This is associated with the action of enzymes found in saliva. For example, hyaluronidosis > permeability of Ca and glycine, especially in the area of ​​the carious spot. Chemotrypsin and whole phosphatosis< проницаемость для CaF и лизина. Кислая фосфатоза >permeability for all ions and substances.

It has been proven that amino acids (lysine, glycine), glucose, fructose, galactose, urea, nicotinamide, vit, and hormones penetrate into tooth enamel.

Permeability depends on the age of the person: the greatest - after tooth eruption, it decreases by the time the tooth tissues mature and continues to decrease with age. From 25 to 28 years > resistance to caries, a complex exchange occurs while maintaining a constant composition of the enamel.

Saliva pH, as well as a decrease in pH under dental plaque, where organic acids are formed, permeability increases due to the activation of enamel demineralization by acids.

Caries > permeability. At the stage of white and pigmented spots > permeability, > the possibility of penetration of various ions and substances, as well as Ca and phosphates - these are compensatory reactions in response to active demineralization. Not every carious spot turns into a carious cavity; caries develops over a very long time.

Hyposalivation leads to the destruction of enamel. Caries that occurs at night is a nocturnal disease.

Surface formations on teeth

These are mucin, cuticle, pelicula, plaque, stone.

Mucin is a complex protein, related to salivary glycoproteins, which covers the surface of the tooth and performs a protective function, protects against mechanical and chemical influences, its protective role is explained by the characteristics, specificity of the amino acid composition and the characteristics of the content of sulfur, trianine, which contain up to 200 amino acids, pro... It is attached to sulfur and trianine residues through an O-glycosidic bond. N-acetylneuramine residues. to-you, N-acetylglucosamine, galactose and f..zy. The structure of the protein resembles a comb, which has ... proteins, residues consisting of amino acids, and carbohydrate components are arranged in protein chains, they are connected to each other by disulfide bridges and form large molecules capable of holding H O. They form a gel.

Pellicle

This is a thin, transparent film of carbohydrate-protein nature. Includes glycine, glycoproteins, some amino acids (ala, glu), Jg, A, G, M, amino sugars, which are formed as a result of the vital activity of bacteria. The structure contains 3 layers: 2 on the surface of the enamel, and the third in the surface layer of the enamel. The pellicle covers the dental plaque.

Plaque

White soft film located in the cervical area and on the entire surface. Removed during cleaning and hard food. This is a cariogenic factor. Represents a destructive organ with a large number of substances found in the oral cavity, as well as their waste products. 1 g of dental plaque contains 500 x 10 microbial cells (streptococci). There are early plaque (during the first day) and mature plaque (from 3 to 7 days).

3 hypotheses for plaque formation

1) …

2) precipitation of salivary glycoproteins that react in bacteria

3) pricipitation of intracellular polysaccharides. They are formed by streptococci, called dextran and levan. If you centrifuge dental plaque and pass it through a filter, two fractions are separated, cellular and acellular. Cellular – epithelial cells, streptococci, (15%). ....you, diphtheroids, staphylococci, yeast-like fungi - 75%.

In dental plaque, 20% is dry matter, 80% is H O. Dry matter contains minerals, proteins, carbohydrates, and lipids. From mineral ingredients: Ca – 5 mcg/per 1 g of dry plaque. P – 8.3, Na – 1.3, K – 4.2. There are microelements Ca, Str, Fe, Mg, F, Se. F soda in dental plaque in three forms:

1) CaF - Ca fluoride

1) CF protein complex

2) F in M/O structure

Some microelements reduce the susceptibility of teeth to caries F, Mg, others reduce resistance to caries - Se, Si. Proteins from dry plaque – 80%. The protein and amino acid composition is not identical to that of mixed saliva. As amino acids mature, they change. Gly, arg, lys, >glutomate disappears. Carbohydrates 14% - fructose, glucose, hexosamines, salic acids and acids, and glucosamines.

With the participation of enzymes from plaque bacteria, polymers are synthesized from glucose - dextran, and from fructose - levan. They form the basis of the organic matrix of dental plaque. The microorganisms involved in the pre...tion are split, respectively, by dext...heat and levanous cariogenic bacteria streptococci. Available in limited quantities: maktak, pyruvate, acetic acid, propionic acid, citric acid. This leads to a decrease in pH under dental plaque on the surface of the enamel to 4.0. These are cariogenic conditions. Therefore, dental plaque is one of the important etiological and pathogenic links in the development of caries and periodontal diseases.

Lipids

Early dental plaque contains triglycerides, glycerol, and glycerophospholipids. In mature quantity< , образуются комплексы с углеводами – глицерофосфолипиды.

Many hydrolytic and proteolytic enzymes. They act on the organic enamel matrix, destroying it. Relative glycosidoses. their activity is 10 times higher than in saliva. Acidic, alkaline phosphatases, pH, DN-noses. Peroxidases.

The metabolism of dental plaque depends on the nature of the microflora. If streptococci predominate in it, then pH<, но рн зубного налета может и повышаться за счет преобладания акти….тов и стафиллококков, которые обладают уреалитической активностью, расщепляют мочевину, NН, дезаминируют аминокислоты. Образовавшийся NH соединяется с фосф-и и карбонатами Са и Мg и образуется сначала аморфный карбонат и фосфат Са и Мg, некристаллический ГАП - - ->crystal.

Dental plaque mineralizes and turns into tartar. Especially with age, with certain types of pathology in children - tartar deposits are associated with congenital heart lesions, S.D.

Tartar (ZK)

This is a pathological discalcified formation on the surface of the teeth. There are supragingival, subgingival z.k. They differ in location, chemical composition and chemistry of formation.

Chemical composition of g.c.

Min. content 70 – 90% dry content.

Amount of mineral substances in s.c. various. Dark z.k. contains more minerals than light. What > ​​zk is mineralized, mem > Mg, Si, Str, Al, Pb. First, the low-mineralized substances of ZK are collected, which are 50% composed of bruslit substances Ca NPO x 2H O.

Octocalcium phosphate Ca H (PO) x 5H O

Carbonate apatites Ca (PO CO)

Ca (PO) CO (OH).

Hydroxyapatite Ca (PO) (OH

Viktolit – (Ca Mg) (PO)

Is in zk –F is contained in the same 3 forms, as in dental plaque.

Proteins, depending on the maturity of the cell, range from 0.1 to 2.5%. Number of proteins< по мере минерализации зк. В наддесневом зк сод-ся 2,5%. В темн.наддесневом зк – 0,5%, в поддесневом – 0,1%

Knowledge B. VZK are calcium-precipitating glyco- and phosphoproteins. The carbohydrate part of which is represented by galactose, fructose, ointment. In a ratio of 6:3:1.

Feature of the amino acid composition - no cyclic amino acids

GPL lipids are synthesized by dental plaque microorganisms. Capable of binding Ca to proteins and initiating the formation of HAP. There is ATP in the cell, it is both a source of energy and also a donor of organophosphorus. during the mineralization of brulite and its transformation into TAP. Brulite turns into octocalcium phosphate ---> HAP (at pH>8). Brulite - ATP -> octocalcium phosphate -> HAP.

Biochemical changes in hard dental tissues during caries, prevention of caries by remineralization method

Initial biochemical changes occur at the boundary between the surface of the enamel and the base of the tartar. The primary clinical manifestation is the appearance of a carious spot (white or pigmented). In this area of ​​enamel, demineralization processes first occur, especially pronounced in the subsurface layer of enamel, and then changes occur in the organic matrix, which leads to enamel permeability. Demineralization occurs only in the area of ​​the carious spot and it is associated with an increase in the microspace between the HAP crystals, > the solubility of enamel in an acidic environment, 2 types of reactions are possible depending on the acidity:

Ca(PO)(OH) + 8H = 10Ca + 6 HPO + 2 HO

Ca(PO)(OH) + 2H = Ca(HO)(PO)(OH) + CA

Reaction No. 2 leads to the formation of apatite in the structure of which there are instead of 10.9 Ca atoms, i.e.< отношение Са/Р, что приводит к разрушению кристаллов ГАП, т.е. к деминерализации. Можно стимулировать реакцию по первому типу и тормозить деминерализацию. 2 эт.развития кариеса – появление кар.бляшки. Это гелеподобное в-во углеводно-белковой природы, в нем скапливаются микроорганизмы, углеводы, ферменты и токсины. Бляшка пористая, через нее легко проникают углеводы. 3 эт. – образование органических кислот из углеводов за счет действия ферментов кариесогенных бактерий. Сдвиг рн в кисл.сторону., происходит разрушение эмали, дентина, образование кариозной полости.

Prevention and treatment of caries with remineralizing agents

Remineralization is a partial change or complete restoration of the mineral components of tooth enamel due to components of saliva or remineralizing solutions. Remineralization is based on the adsorption of minerals into carious areas. The criterion for the effectiveness of remineralizing solutions is such properties of enamel as permeability and solubility, disappearance or reduction of carious spots,< прироста кариеса. Эти функции выполняет слюна. Используются реминерализующие растворы, содержащие Са, Р, в тех же соотношениях и количествах, что и в слюне, все необходимые микроэлементы.

Remineralizing solutions have a greater effect than mixed saliva.

In saliva, Ca and P combine with organic complexes of saliva and the content of these complexes decreases in saliva. These solutions must contain F in the required amount, since it affects the rejuvenation of Ca and P in the hard tissues of the tooth and bone. At< концентрации происходит преципитация ГАП из слюны, в отсутствии F преципитация ГАП не происходит, и вместо ГАП образуется октокальцийфосфат. Когда F очень много обр-ся вместо ГАП несвойственные этим тканям минеральные в-ва и чаще CaF .

Hypothesis of caries pathogenesis

There are several hypotheses:

1) neurotrophic caries is considered as a result of human conditions and the influence of factors on him external environment. The authors attached great importance to the central nervous system

2) trophic. The mechanism of caries development is a violation of the trophic role of odontoblasts

3) appeal theory. Caries is the result of pelation of enamel by complexes of mixed saliva. Caries is the result of simultaneous organ proteolysis and pelation miner in-in enamels

4) acidogenic or chemical-karyositotic. It is based on the effect of acid-reacting substances on tooth enamel and the participation of microorganisms in the carious process. It was proposed 80 years ago and forms the basis of the modern hypothesis of the pathogenesis of caries. Caries of decalcified tissues caused by acids, image. as a result of the action of microorganisms on carbohydrates.

Cariogenic factors are divided into factors of a general and local nature.

General:

include poor nutrition: excess carbohydrates, lack of Ca and P, deficiency of microelements, vitamins, proteins, etc.

Diseases and changes in the functional state of organs and tissues. Adverse effects during teething and maturation and in the first year after teething.

Electrical air (ionizing radiation, stress), which affects the salivary glands, the secreted saliva does not correspond to the normal composition, and it affects the teeth.

Local factors:

1) plaque and bacteria

2) changes in the composition and pH of mixed saliva (pH shift to the acidic side, lack of F, decrease in the amount and ratio of Ca and P, etc.)

3) carbohydrate diet, carbohydrate food residues.

Anti-cariogenic factors and dental caries resistance

1) susceptibility to caries depends on the type of mineralization of hard dental tissues. Yellow enamel is more caries-resistant. With age, the crystal lattice becomes denser and the caries resistance of teeth increases.

2) Caries resistance is promoted by the replacement of HAP with fluorapatites - stronger, more acid-resistant and poorly soluble. F is an anti-cariogenic factor

3) Caries resistance of the surface layer of enamel is explained by the increased content of microelements in it: stanium, Zn, Fe, Va, tungsten, etc., and Se, Si, Cd, Mg are cariogenic

4) Dental caries resistance is promoted by vit. D, C, A, B, etc.

5) Mixed saliva has anti-cariesogenic properties, i.e. its composition and properties.

6) Particular importance is attached citric acid, citrate.

F and strontium

F is found in all tissues of the body. Available in several forms:

1) crystal. form of fluorapatite: teeth, bones

2) in combination with organic. in-you glycoproteins. Image of an organic matrix of enamel, dentin, bones

3) 2/3 total number F found in the ionic state in biol.

liquids: blood, saliva. A decrease in F in enamel and dentin is associated with a change in pit.H O.

It is easier for F to be included in the enamel structure in a slightly acidic environment, the amount of F in bones increases with age, and in the teeth of children it is found in increased quantities during the maturation of hard tooth tissues and immediately after eruption.

With very large amounts of F in the body, poisoning with fluorine compounds occurs. It is expressed in increased fragility of bones and their deformation due to disruption of R-Ca metabolism. As with rickets, but the use of vitamin D and A does not cause a significant effect on the disturbance of P-Ca metabolism.

A large amount of F has a toxic effect on the entire body, due to a pronounced inhibitory effect on the metabolic processes of carbohydrates, fats, and tissue respiration.

Role F

They take part in the process of mineralization of teeth and bones. The strength of fluorapatites is explained by:

1) amplification bonds between Ca ions in the crystal lattice

2) F binds to organic matrix proteins

3) F contributes to the formation of more durable crystals of HAP and F-apatites

4) F helps to activate the process of precipitation of apatites of mixed saliva and thereby increase. its remineralizing function

5) F affects the bacteria of the oral cavity, acid-forming properties are burned and thereby prevents the pH from shifting to the acidic side, because F inhibits ecolase and suppresses cliquelysis. The anti-caries effect of F. is based on this mechanism.

6) F takes part in regulating the entry of Ca into the hard tissues of the tooth, reducing the permeability of enamel to other substrates and increasing caries resistance.

7) F stimulates reparative processes in case of bone fractures.

8) F reduces the content of radioactive strontium in the bones and teeth and reduces the severity of rickets. Sr competes with Ca for inclusion in the HAP crystal lattice, and F suppresses this competition.

Ascorbic acid. Function. Role in the metabolism of tissues and organs of the oral cavity

1) the effect of the vitamin is associated with its participation in OM reactions. It accelerates the dehydrogenation of reduction. coenzymes NADH, etc., activates the oxidation of glucose by PFP, which is so characteristic of dental pulp.

2) Vitamin C affects the synthesis of glycogen, which is used in teeth as the main source of energy during the mineralization process.

3) Vit.C active. many enzymes carbohydrate metabolism: in glycolysis – hexose, phosphofructokinosis. In CGC...hydrogenosis. In tissue respiration - cytochrome oxidosis, as well as mineralization enzymes - alkaline phosphatosis

4) Vit.C is directly involved in the biosynthesis of protein, compound, procollagen in its transformation into collagen. This process is based on 2 reactions

proline - -axiproline

Ph-t: proline hydroxylase, cof-t: vit C.

Lysine – oxylysine f-t: lysine hydroxylase, cof-t: vit.C

Vitamin C performs another function: activation of enzymes by reducing disulfide bridges in enzyme proteins to sulhydryl groups. As a result of activation of alkaline phosphatosis, ... dehydrogenase, cytochromexidosis.

Vitamin C deficiency affects the condition of the periodontium, the formation of intercellular substance in the connective tissue decreases

5) vitamin deficiency changes the reactivity of tooth tissue. May cause scurvy.

Section 2. Dental caries

001. Ca 10 (PO 4)6(OH) 2 is

1) carbonapatite

2) chlorapatite

4) whitlockite

5) hydroxyapatite
002. Hard tissues of the tooth are characterized by a calcium-phosphorus ratio

3) 2,1
003. Solubility of dental enamel hydroxyapatite

when the pH of the oral fluid decreases

1) increases

2) decreases

3) does not change
004. Enamel microhardness in caries at the spot stage

1) decreases

2) increases

3) does not change
005. Enamel permeability increased

1) in the white spot stage

2) with fluorosis

3) with hypoplasia

4) upon abrasion
006. Ion exchange processes, mineralization and demineralization

provides

1) microhardness

2) permeability

3) solubility
007. For dental caries in the white spot stage, protein content

in the lesion body

1) increases

2) decreases

3) does not change
008. For dental caries in the white spot stage, calcium content

in the lesion body

1) increases

2) decreases

3) does not change

009. For dental caries in the white spot stage, phosphorus content

in the lesion body

1) increases

2) decreases

3) does not change
010. For dental caries in the white spot stage, fluoride content

in the lesion body

1) increases

2) decreases

3) does not change
011. Enamel hydroxyapatite formula

1) SaNRON 4

2) Ca 10 (PO 4) 6 (OH) 2

3) Ca 10 (PO 4) 8 (OH) 2

012. With average caries, probing the cavity is painful

1) along the edge of the enamel

2) along the enamel-dentin junction

3) along the bottom of the carious cavity

013. Phosphoric acid permeability of enamel

1) increases

2) lowers

3) does not change

014. Sodium fluoride enamel permeability

1) increases

2) lowers

3) does not change

015. Saline solution permeability of enamel

1) increases

2) lowers

3) does not change

016. Lactic acid permeability of enamel

1) increases

2) lowers

3) does not change

017. Calcium gluconate solution enamel permeability

1) increases

2) lowers

3) does not change

018. Remodent solution, enamel permeability

1) increases

2) lowers

3) does not change

019. Remineralization of tooth enamel is determined by its

1) microhardness

2) permeability

3) solubility
020. The most characteristic clinical symptom

for caries different stages- pain

1) spontaneous

2) persisting after removal of the stimulus

3) only in the presence of a stimulus
021. Cavity with superficial caries localized within

2) enamel and dentin

022. The cavity with average caries is localized within

2) enamel and dentin

3) enamel, dentin and predentin
023. The cavity with deep caries is localized within

2) enamel and dentin

3) enamel, dentin and predentin
024. Methods for diagnosing caries at the spot stage

1) staining and EDI

2) radiography and EDI

3) radiography and thermal diagnostics

4) thermal diagnostics and fluorescent stomatoscopy

5) fluorescent stomatoscopy and staining
025. Vital staining method reveals lesions

demineralization of enamel

1) with enamel erosion

2) for caries in the white spot stage

3) with a wedge-shaped defect

4) with hypoplasia

5) for caries in the pigmented spot stage
026. For vital staining of tooth enamel when diagnosing caries

use

1) erythrosine

3) methylene blue

4) potassium iodide

5) Schiller–Pisarev solution

027. Remineralizing therapy involves

entry of substances into the site of demineralization

1) mineral

2) organic

028. Deep caries is differentiated

1) with average caries

2) with chronic pulpitis

3) with chronic periodontitis

4) with fluorosis

029. Etching the enamel ensures contact with the tooth enamel

with composite material according to the principle

1) micro clutches

2) chemical interaction

3) adhesion

030. Sealants are used for prevention

1) caries

2) fluorosis

3) hypoplasia

031. For better retention of the composite material

the enamel is prepared by

1) fluoridation

2) creating a fold

3) acid pickling

032. Restorative filling materials include

1) zinc-eugenol paste

2) glass ionomer cement

3) potassium hydroxide

4) composite materials

5) compomers

033. List the methods of filling cavities

1) sandwich technique

2) step-back

3) tunnel method

034. The composition of the composite material includes

1) phosphoric acid

2) filler

035. For etching enamel before filling

the composite material uses acid

1) salt

2) fluorescent

3) orthophosphoric

036. Glass ionomer cement is used

1) for aesthetic filling

2) for filling temporary teeth

3) for fixing pin structures

4) to create a tooth stump for a crown
037. Groups of composite materials include

1) microphylls

2) macrophylls

3) hybrid

4) neutrophils
038. Bonding systems include

1) primer

2) acid

3) adhesive

4) polishing paste
039. Color of filling material for aesthetic restoration

should be selected under the following conditions

1) in the dark on a dried tooth surface

2) under artificial light

after etching the tooth surface with acid

3) in natural light on a damp tooth surface
040. For the restoration of the frontal group of teeth it is used

1) amalgam

2) microfilled composites

3) cement phosphate

4) dentin paste
041. Used for sandwich filling technique

combination of materials

1) phosphate cement + amalgam

2) glass ionomer cement + composite

3) apexit + dentin paste
042. For polishing the surface of a filling made of composite material

use

1) finely dispersed diamond turbine burs

2) Gates burs

3) silicone polishers

4) SoftLex wheels

5) carbide finishes
043. For filling cavities of class 1 and 2 according to Black, use

1) microfilled composites

2) hybrid composites

3) packable composites

044. Composite materials by type of polymerization

are divided into

1) light-hardening

2) chemical curing

3) double curing

4) infrared curing
045. In the chewing group of teeth when filling according to class 2 according to Black

contact point is created

1) planar

2) point

3) stepped
046. When applying a one-component bonding system

the dentin surface should be

1) overdried

2) slightly damp

3) abundantly moisturized
047. Causes of post-filling pain after use

light-curing composites can be

1) applying bonding to overdried dentin

2) violation of polymerization technique

3) use of abrasive paste when polishing the filling
Match
048. Type of filling material Black class

1) flowable composite a) 1 (large cavity)

2) packable composite b) 2

3) microfilled composite c) 3, 4

d) 5
Please indicate the correct sequence
049. Stages of filling a cavity with composite materials

1) applying bonding

2) applying cushioning material

3) etching of enamel

4) polishing the filling

5) adding filling material
050. Distribute filling materials

as their aesthetic properties increase

1) composites

2) compomers

3) glass ionomers

Subject: Clinical signs healthy and changed enamel. The structure of enamel. Goal: To develop and teach students criteria for assessing healthy and pathologically altered tooth enamel. During classes with students, I analyze the endogenous and exogenous factors that influence the color change of the integrity of the enamel.

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PAGE 5

METHODOLOGICAL DEVELOPMENT

practical lesson No. 4

by section

IV semester).

Subject: Clinical signs of healthy and altered enamel. The structure of enamel. Determination of permeability, test with methylene blue, its implementation.

Target: Develop and teach students criteria for assessing healthy and pathologically altered tooth enamel.

Class location: Hygiene and prevention room of State Clinical Hospital No. 1.

Material support:Typical equipment of a hygiene room, dentist's workplace - prevention, tables, stands, dyes (2% methylene blue solution), ten-field halftone scale, laptop.

Lesson duration: 3 hours (117 min).

Lesson plan

Lesson stages	Equipment	Training aids and controls	Place	Time per minute
1. Checking the initial data.	Lesson content plan. Laptop.	Test questions and tasks, tables, presentation.	Hygiene room (clinic).
2. Solving clinical problems.	Laptop, tables.	Forms with control situational tasks.	— || —	74,3%
3. Summing up the lesson. Assignment for the next lesson.		Lectures, textbooks, additional literature, methodological developments.	— || —

The lesson begins with the teacher briefing on the content and goals of the lesson. During the survey, find out the students' initial level of knowledge. During classes with students, I analyze endogenous and exogenous factors that influence changes in color and integrity of enamel. Next, the risk zones of enamel, the structure and signs of healthy and altered enamel, as well as the permeability of healthy and altered enamel for various substances (Ca, P, F , amino acids, dyes). The teacher and students discuss the method of vital enamel staining. The lesson ends with solving situational problems and test tasks.

When determining the color and integrity of the enamel, such types of pathology as caries, hypoplasia, fluorosis, wedge-shaped defect are analyzed when determining the shape of teeth sharp and chronic injuries teeth, hereditary diseases when determining the shine and morbidity of teeth, diabetes mellitus, xerostomia. Particular attention is paid to acquired structures of the oral cavity and their effect on changes in tooth color.

For more precise definition There are a number of indices for health status: KPU, KP, KPU+KP. They are needed to determine the epidemiological status in the region or throughout the country, they can be used to plan dental care, it is necessary for the formation of separate groups during prevention, and serves as a criterion for sanitation and preventive measures. If KPU = 6 this indicates high caries damage, with KPU = 2-3 moderate and less than 2 low caries damage.

In the city of Omsk, KP = 5.3, and in different age groups it fluctuates, for example, at 7 years old, KP + kp = 8.3. It is necessary to draw students’ attention to identifying the activity of the carious process (according to T.F. Vinogradova), compensated, sub- and decompensated forms.

Of great importance for identifying the degree of caries activity is the detection and quantitative assessment of focal demineralization (white carious spots) according to L.A. Aksamit (1979).

Violations of the structure of enamel and dentin can occur under the influence of a wide variety of causes and have numerous clinical manifestations. The most common cause of disruption of the structural integrity of hard tissues is dental caries. At the same time, starting with the loss of natural shine and a change in color in a certain area, the enamel acquires a rough consistency, and due to active demineralization, a defect of varying depth appears. In case of non-carious lesions of teeth (hypoplasia and hyperplasia, fluorosis, hereditary disorders of the development of dental tissues, non-carious pathology that arose after their eruption; traumatic injuries, abrasion, acid necrosis, wedge-shaped defect, necrosis, erosion), specific changes in the structure of enamel and dentin occur, often combined with irregularities in shape and size. Thus, with hypoplasia, along with a change in the color of the enamel, signs of its underdevelopment appear in the form of fibrous, dotted, grooved defects up to complete absence enamel (aplasia). In case of fluorosis specific hypoplasia caused by excess fluoride in drinking water violations of the enamel structure of 5 forms are detected: streaked, spotted, chalky-speckled, erosive and destructive. Hyperplasia (enamel drops) occurs in approximately 1.5% of the population (Borovsky E.V., 1989). Hereditary disorders development of dental tissues manifests itself in a variety of clinical forms: color changes, partial or complete loss of tissue.

The method for determining enamel permeability, developed by E.V., has acquired particular importance for diagnosing the clinical condition and changes in the process of treating the initial manifestations of dental caries. Borovsky, P.A. Leusom, L.A. Aksamit (1979). It is based on intravital staining of foci of demineralization in initial caries 2% aqueous solution methylene blue. The dye easily penetrates into carious spots as a result of a significant increase in the permeability of the enamel in this area.

The teeth to be examined are isolated from saliva with cotton swabs. Their surface is thoroughly cleaned of plaque and tartar. Then a cotton swab moistened with a solution of methylene blue is applied to the area of ​​enamel to be examined for 3 minutes. After the specified time, the tampon is removed and the excess is washed off with water. If there is focal demineralization of the enamel, the spot becomes blue in color. Dark spots, spots with hypoplasia and fluorosis are not stained.

Using this method, it is possible to determine the exact size and shape of the area of ​​focal demineralization, as well as hidden lesions invisible to the eye. Since the amount of dye penetrating deep into the enamel depends on the degree of violation of the permeability of the enamel, the more blue penetrates into the enamel, the stronger violation this process and its deeper structural disturbances. The degree of these violations is semi-quantitatively determined by comparison with a ten-field gradation scale of various shades of blue, produced for printing needs. The staining of the spots disappears spontaneously within 1 hour.

The application of this method in the dynamics of clinical observation and treatment of caries is of great practical interest. Changing the parameters of the stain in terms of size, uniformity of color, and degree of permeability allows you to monitor the progress of the carious process and regulate it. The method is simple, accessible and applicable at the doctor’s workplace.

Test questions to identify background knowledge students:

1. What endogenous and exogenous factors influence tooth color change?
2. Talk about the structure of enamel.
3. List the signs of healthy enamel.
4. What types of pathology affect the integrity of the enamel?
5. What diseases lead to tooth discoloration?
6. The concept of enamel permeability. When was it accepted?
7. To what substances is enamel permeable?
8. What is the significance of enamel permeability for the clinician?
9. By what signs is the activity of the carious process assessed?

Scheme of the indicative basis of action

determining the clinical condition of teeth

1. Determine the level of damage
Enamel: color shine moisture integrity	Compare with healthy teeth	The color of all teeth is the same and ranges from bluish to light brown. By the appearance of chalky spots lacking shine, one can judge about focal demineralization. Dry enamel occurs with diseases of the salivary glands and diabetes. By the presence of an enamel defect, complicated or uncomplicated caries is judged.
2. Swipe differential diagnosis
Diseases with a similar clinical picture: Hypoplasia Fluorosis	Compare with signs of focal demineralization	Signs uncharacteristic of caries: Teeth of the same period of formation are affected; Symmetrical lesions with identical defects; Aniline dyes do not cover stains. A. Teeth of the same period of formation or a large group of teeth are affected; b. There may be identical or different elements (spots, erosions, mottling) in different areas of the crowns; V. Aniline dyes do not cover stains.
3. Determine the location of the lesion (risk zone)
Cervical region Contact surface Chewing surface Vestibular surface Lingual surface		For circular caries of temporary and permanent teeth. Favorite localization for caries. More typical for permanent teeth. It is rarely affected except in the blind fossae. It is extremely rarely affected.
4. Determine enamel permeability
Coloring enamel stains Before staining, soft plaque is removed using a cotton swab soaked in 3% H2O2 solution, the tooth is isolated from saliva and paint is applied for 3 minutes.	2% methylene blue solution	The degree of permeability is determined on a ten-field halftone scale (L.A. Aksamit, 1978) and is expressed in %.
5. Determine the degree of dental caries damage
With the help of inspection and probing we identify: a) in temporary dentition kp b) in mixed dentition KP + KPU c) in permanent dentition CPU	Mirror, probe	To - carious temporary teeth To - carious temporary teeth P - filled temporary teeth U - extracted permanent teeth due to complicated caries TO - carious permanent teeth P - filled permanent teeth U - extracted permanent teeth regarding complicated caries.

Situational tasks

1. A 12 year old girl has rheumatism, chronic tonsillitis. In the neck area there are 11, 12, 21, 22 chalky stripes. Which additional methods examinations will help clarify the diagnosis and conduct differential diagnostics. What diagnosis can be assumed?
2. A 12-year-old boy complains of a cosmetic defect. According to the mother, the child had been suffering from pneumonia for a year. On the vestibular surface 11, 16, 21, 26, 36, 46 there are cup-shaped depressions, dark brown in color, dense on probing, painless. Probable diagnosis?
3. A 3-year-old child's tooth enamel is gray-yellow. In the second half of pregnancy, the mother took tetracycline antibiotics. Probable diagnosis and your tactics?
4. A 10-year-old child has light brown enamel pigmentation foci on the vestibular surface of his incisors. The enamel has a matte tint; from birth until the age of 7, the child lived in a center of endemic fluorosis. Diagnosis. Tactics.
5. A 4-year-old child has caries on the lower fourth teeth and the upper fifth teeth (74, 84 and 65). Write down the formula, calculate the kp index. Which activity group should the child be assigned to?
6. A 13-year-old child had 36 removed, 11, 21, 46 caries, and 26 had chronic pulpitis. Calculate the CPU index.
7. In a 10-year-old child, 36, 46 were removed due to complicated caries. Calculate the caries susceptibility index.

List of literature for preparation for classes in the section

"Prevention and epidemiology of dental diseases"

Department of Dentistry childhood Omsk State Medical Academy ( IV semester).

Educational and methodological literature (basic and additional with the stamp of educational qualifications), including those prepared at the department, electronic textbooks, network resources:

Prevention section.

A. BASIC.

1. Pediatric therapeutic dentistry. National leadership: [with adj. on CD] / ed.: V.K. Leontiev, L.P. Kiselnikova. M.: GEOTAR-Media, 2010. 890 p. : ill.- (National Project “Health”).
2. Kankanyan A.P. Periodontal diseases (new approaches in etiology, pathogenesis, diagnosis, prevention and treatment) / A.P. Kankanyan, V.K. Leontiev. - Yerevan, 1998. 360s.
3. Kuryakina N.V. Preventive dentistry (guidelines for primary prevention of dental diseases) / N.V. Kuryakina, N.A. Savelyeva. M.: Medical book, N. Novgorod: NGMA Publishing House, 2003. - 288 p.
4. Kuryakina N.V. Therapeutic dentistry of children / ed. N.V. Kuryakina. M.: N. Novgorod, NGMA, 2001. 744 p.
5. Lukinykh L.M. Treatment and prevention of dental caries / L.M. Lukinykh. - N. Novgorod, NGMA, 1998. - 168 p.
6. Primary dental prevention in children. / V.G. Suntsov, V.K. Leontiev, V.A. Distel, V.D. Wagner. Omsk, 1997. - 315 p.
7. Prevention of dental diseases. Textbook Manual / E.M. Kuzmina, S.A. Vasina, E.S. Petrina et al. M., 1997. 136 p.
8. Persin L.S. Pediatric dentistry / L.S. Persin, V.M. Emarova, S.V. Dyakova. Ed. 5th revised and expanded. M.: Medicine, 2003. - 640 p.
9. Handbook of pediatric dentistry: trans. from English / ed. A. Cameron, R. Widmer. 2nd ed., rev. And additional M.: MEDpress-inform, 2010. 391 p.: ill.
10. Dentistry of children and adolescents: Per. from English / ed. Ralph E. MacDonald, David R. Avery. - M.: Medical information Agency, 2003. 766 pp.: ill.
11. Suntsov V.G. Basic scientific works Department of Pediatric Dentistry / V.G. Suntsov, V.A. Distel and others - Omsk, 2000. - 341 p.
12. Suntsov V.G. The use of therapeutic and prophylactic gels in dental practice / ed. V.G. Suntsova. - Omsk, 2004. 164 p.
13. Suntsov V.G. Dental prevention in children (a guide for students and doctors) / V.G. Suntsov, V.K. Leontyev, V.A. Distel. M.: N. Novgorod, NGMA, 2001. 344 p.
14. Khamadeeva A.M., Arkhipov V.D. Prevention of major dental diseases / A.M. Khamdeeva, V.D. Arkhipov. - Samara, SamSMU 2001. 230 p.

B. ADDITIONAL.

1. Vasiliev V.G. Prevention of dental diseases (Part 1). Educational and methodological manual / V.G. Vasiliev, L.R. Kolesnikova. Irkutsk, 2001. 70 p.
2. Vasiliev V.G. Prevention of dental diseases (Part 2). Educational and methodological manual / V.G. Vasiliev, L.R. Kolesnikova. Irkutsk, 2001. 87 p.
3. Comprehensive program dental health of the population. Sonodent, M., 2001. 35 p.
4. Methodological materials for doctors, preschool teachers, school accountants, students, parents / ed. V.G. Vasilyeva, T.P. Pinelis. Irkutsk, 1998. 52 p.
5. Ulitovsky S.B. Oral hygiene - primary prevention dental diseases. // New in dentistry. Specialist. release. 1999. - No. 7 (77). 144 p.
6. Ulitovsky S.B. Individual hygienic program for the prevention of dental diseases / S.B. Ulitovsky. M.: Medical book, N. Novgorod: NGMA Publishing House, 2003. 292 p.
7. Fedorov Yu.A. Oral hygiene for everyone / Yu.A. Fedorov. St. Petersburg, 2003. - 112 p.

The staff of the Department of Pediatric Dentistry published educational and methodological literature with the stamp of UMO

Since 2005

1. Suntsov V.G. Guide to practical classes in pediatric dentistry for students of the pediatric faculty / V.G. Suntsov, V.A. Distel, V.D. Landinova, A.V. Karnitsky, A.I. Mateshuk, Yu.G. Khudoroshkov. Omsk, 2005. -211 p.
2. Suntsov V.G. Guide to pediatric dentistry for students of the pediatric faculty / V.G. Suntsov, V.A. Distel, V.D. Landinova, A.V. Karnitsky, A.I. Mateshuk, Yu.G. Khudoroshkov. - Rostov-on-Don, Phoenix, 2007. - 301 p.
3. The use of therapeutic and prophylactic gels in dental practice. Guide for students and doctors / Edited by Professor V.G. Suntsov. - Omsk, 2007. - 164 p.
4. Dental prophylaxis in children. Guide for students and doctors / V.G. Suntsov, V.K. Leontyev, V.A. Distel, V.D. Wagner, T.V. Suntsova. - Omsk, 2007. - 343 p.
5. Distel V.A. Main directions and methods of prevention of dental anomalies and deformations. A manual for doctors and students / V.A. Distel, V.G. Suntsov, A.V. Karnitsky. Omsk, 2007. - 68 p.

Electronic tutorials

Program for ongoing monitoring of students' knowledge (preventive section).

Methodological developments for practical classes of 2nd year students.

“On increasing the efficiency of delivery dental care children (draft order dated February 11, 2005).”

Requirements for sanitary and hygienic, anti-epidemic regimes and working conditions for workers in non-state health care facilities and the offices of private dental practitioners.

Structure of the Dental Association of the Federal District.

Educational standard for postgraduate professional training of specialists.

Illustrated material for state interdisciplinary exams (04.04.00 “Dentistry”).

Since 2005, employees of the department have published electronic teaching aids:

Tutorial Department of Pediatric Dentistry Omsk State Medical Academyunder the section “Prevention and Epidemiology of Dental Diseases”(IV semester) for students of the Faculty of Dentistry /V.G.Suntsov, A.Zh.Garifullina, I.M.Voloshina, E.V.Ekimov. Omsk, 2011. 300 Mb.

Videos

1. Educational cartoon on teeth cleaning from Colgate (pediatric dentistry, prevention section).
2. “Tell Doctor”, 4th scientific and practical conference:

G.G. Ivanova. Oral hygiene, hygiene products.

V.G. Suntsov, V.D. Wagner, V.G. Bokaya. Problems of dental prevention and treatment.

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