• CRT (color reaction time) – color reaction time (Walter, 1958; Mayvold, Jager, 1978)
• TER (enamel resistance test) (Okushko V.R., 1984)
• Laser reflexometry (Grisimov V.P., 1991)
• Electrometry (Ivanov G.G., 1984; Zhorova I.A., 1989)
• Determination of the amount of calcium and phosphorus in enamel ash
• Enamel biopsy (determination of intravital enamel solubility); (Leontyev V.K., Distel V.A., 1974)
• Spectrometry
CRT (color reaction time)
• Purpose: to study the rate of dissolution of enamel in acid
• Method: study the time required to neutralize a standard amount of acid with ions more or less actively emerging from enamel apatites dissolved by this acid. The transition from an acidic to a neutral environment is determined using an acid-base indicator
• Materials and equipment: 1N hydrochloric acid solution, micropipette, filter paper disk with a diameter of 3 mm, soaked for 30 seconds in a 0.02% aqueous solution of crystal violette, which is yellow in acidic pH and violet in neutral pH, stopwatch.
• Methodology: tooth 12 is isolated from saliva, cleaned of plaque with a brush and dried. A paper disk is placed on the vestibular surface, and 1.5 μl of 1N HCl is applied to it using a micropipette (after the test, remineralizing agents must be applied)
• Interpretation of results: CRT˃60 s – solubility is low, caries resistance is high; CRT˂60 s – high solubility, low caries resistance
TER (enamel resistance test)
• Purpose: determining the degree of destruction of the surface layers of enamel under the influence of acid
• Method: visual assessment of an enamel defect resulting from the use of a standard acid solution under standard conditions, using a dye that is fixed in larger or smaller quantities in the irregularities of the damaged enamel and therefore gives a more or less intense color.
• Material and equipment: 1N hydrochloric acid solution, micropipette or glass rod, 1% methylene blue solution, 10-point blue scale (standard or prepared using serial dilution of the original solution 1:2 - from 100 to 0.18%)
• Methodology: tooth 12 is isolated from saliva, cleaned of plaque with a brush and dried. A drop of acid with a diameter of 1.5-2 mm is applied to the vestibular surface. After 5 seconds, remove the drop with a dry cotton swab in one movement. A drop of dye is applied to the damaged and adjacent intact enamel for 5 s, after which the dye is wiped off with a dry swab until the intact enamel returns to its original color (the pellicle acquires a barely noticeable blue tint)
• Interpretation of results: pale color 1-3 points – high caries resistance; 4-5 points – moderate caries resistance; 6-7 points – low resistance; 8 points or more – very low caries resistance
Enamel biopsy (determination of intravital solubility)
• Purpose: quantitative analysis of the mineral composition (Ca, P) of enamel, or rather that part of its apatites that react with acid.
• The method is based on the theory that calcium-saturated enamel can, in relatively larger quantities than caries-weakening enamel, release ions of this element to neutralize acid, while maintaining the apatite structure. Enamel is studied in vivo.
• Material and equipment: hydrochloric acid buffer solution (97 ml of 1N HCl and 50 ml of KCl) is mixed and added to 200 ml with distilled water; For viscosity, add glycerin 1:1. Microsyringe for application of buffer solution and aspiration of acid enamel biopsy.
• Methodology: The tooth is isolated from saliva, cleaned, and dried. A drop of demineralizing buffer solution with a volume of 3 μl is applied to the enamel surface. After 1 minute, the drop volume (biopsy) is taken with a microsyringe, the biopsy is transferred into a test tube with 1 ml of distilled water and used for quantitative chemical analysis.
• Interpretation of results: The technique allows you to assess the condition of the enamel in a comparative aspect, therefore it is actively used to study the degree of risk of developing caries in some people compared to others, to study changes in enamel that occur under the influence of mineralizing prophylaxis, etc. (it is important to remember that with an increase in enamel caries resistance due to the formation of fluorapatites in it, the solubility of the enamel decreases, and the amount of calcium in the biopsy drops).
Laser reflectometry. (Grisimov V.P., 1991)
• Purpose: to determine the density of the crystal lattice of the enamel surface. The method is based on the differences in the optical properties of resistant and labile enamel: well-mineralized, dense enamel reflects light more and absorbs it less (i.e. diffusely scatters) than loose caries-labile enamel.
• Material and equipment: helium-neon laser LGN-105 with a wavelength of 0.63 microns. A device for photographing laser light reflected by enamel. Meter of reflected light characteristics.
• Method: the tooth is cleaned, dried, and a beam of laser light is directed at it. The beam of light reflected by the enamel is photographed.
• Interpretation of the results: the diffuse component is less than 0.24 – the enamel is caries-resistant; more than 0.30 – caries-weakening.
According to the degree of resistance of teeth to caries, P. A. Leus identifies 5 groups, which, in descending terms of resistance, are distributed as follows:
1. First and second molars of the lower jaw.
2. First and second molars of the upper jaw.
3. The second premolar of the lower jaw and the first, second premolars of the upper jaw.
4. Maxillary central and lateral incisors, maxillary canine and mandibular first premolar.
5. Central and lateral incisors of the lower jaw, canines of the lower jaw.
If all teeth are healthy, then they should be considered a highly resistant type.
When molars and premolars are affected (the first three groups of tooth resistance according to the classification of P. A. Leus), the average level of tooth resistance in the examined individual is determined.
Involvement of central and lateral incisors in the carious process in addition to molars and premolars (the fourth group of teeth resistance to caries according to the classification of P. A. Leus) indicates a low level of resistance.
Caries damage to all functionally oriented groups of teeth should be considered as a consequence of a very low level of tooth resistance.
Date added: 2015-02-22; | Copyright infringement
Caries is the most common lesion. This disease appears in almost everyone, and is accompanied by unpleasant sensations and sometimes serious complications. However, in dentistry there is such a thing as caries resistance. In everyday life, few people have heard this word and therefore it is unlikely that anyone will be able to give an exact definition of this concept.
What is caries resistance?
In dentistry, a condition called caries resistance is often encountered, but what does this mean? How is this condition characterized?
Caries is a disease of our time; it occurs in almost every person in one form or another. But there are those who have innate immunity, this phenomenon is called caries resistance.
Caries
Classification of caries Dental caries is the most common human disease. Anatomical and physiological characteristics, reactive properties and general resistance of the body in childhood leave their mark on the course of caries. Caries of primary teeth under the age of 2 years is localized mainly on those tooth surfaces that formed in the antenatal period (smooth surfaces of the incisors of the upper and lower jaw), especially if it was unfavorable for the development of the fetus (hypoxia of various etiologies, malnutrition, chronic extragenital diseases of the mother, anemia, toxicosis of pregnancy, etc.). After 3 years, caries affects the chewing surfaces of molars, and after 4 years, the contact surfaces of temporary molars. It should be noted the high incidence of caries on the chewing surface (80.8%) of the first permanent molars. A feature of the carious process is its occurrence during the period of teething (6-7 years - first permanent molars, 11-13 - second permanent molars) and rapid progression due to incomplete mineralization. The largest percentage of the occurrence of initial forms of caries occurs precisely during the period of tooth eruption. An increase in intensity is observed at a later age and is due to the progression of existing foci of initial caries. In accordance with the International Classification of Diseases (ICD-10), the following are distinguished: - By 02.0. Enamel caries. — By 02.1. Dentin caries. — By 02.2. Cement caries. — By 02.3. Suspended dental caries. — By 02.4. Odontoclasia. — By 02.8. Other dental caries. — By 02.9. Dental caries, unspecified. Stain stage (macula cariosa) Focal demineralization of enamel, depending on the nature of the course, is divided into slow and fast-flowing. A differential diagnosis between these forms can be made on the basis of anamnesis, clinical picture (color, size, shape of the lesion), and data from staining of teeth with a methylene blue solution. The clinical picture indicates that demineralization of tooth enamel goes through at least three stages. The early stage is a white spot measuring 1-3 mm. In the 2nd, developed stage, distinctive signs of slow and rapid demineralization of the enamel appear. Slow-flowing demineralization is characterized by uniform changes in the enamel surface: on several teeth one of the stages of development of focal demineralization of the enamel predominates, which suggests the possibility of the simultaneous occurrence of foci of demineralization. The rapid demineralization of enamel in the 2nd stage is characterized by the activity of the process. Foci of demineralization lose clear boundaries, their edges become blurred. The enamel surface is rough, matte. The probe easily gets stuck in the demineralization area. The enamel loses its density and is easily scraped off with an excavator. The intensity of staining is on average 60 points. Increased staining is associated with an increase in enamel porosity. Rapid demineralization moves into the 3rd stage - the defect stage. At this stage, characteristic signs for both forms of damage are also noted. Summarizing the above, G. N. Pakhomov et al. propose the following classification of dental lesions with focal demineralization. Focal demineralization of tooth enamel: 1. Slow: - initial stage; - developed stage; — stage of the defect. 2. Fast-flowing: - initial stage; - developed stage; — stage of the defect. In children who frequently consumed sweets, the slow-moving form of enamel demineralization was 1.7 times more common and the fast-moving form was 3.5 times more common than in children who consumed sweets in moderation. After removing plaque from the entire surface of the tooth, an area of dull white or pigmented (from gray to black) enamel is discovered; the surface is smooth, sometimes rough, but painless and dense. Lesion in the stain stage on the vestibular and cervical surfaces of the tooth most often appears in children with the third degree of caries activity on a large group of teeth, up to the defeat of all teeth. It can occur in children of any age. The slow-onset form of enamel demineralization most often affected the incisors of the upper jaw (54.9%). In 2nd place in terms of the frequency of detection of a cervical slow process was the group of lower incisors (17.9%), followed by the group of small molars of the lower (8.7%) and upper (6.7%) jaws. Foci of rapid demineralization of enamel were more common on the upper incisors (45.8%) than on the lower jaw (21.5%). The canines of the upper (7.2%) and lower (7.4%) jaws, as well as the small molars of the upper (9.1%) and lower (9%) jaws were affected equally. Superficial caries (caries superficialis) . It is characterized by softening of the affected enamel, which is removed with a little effort by an excavator. Most children at this stage do not complain. Some of them indicate pain from sweets and sours, and children 1-3 years old refuse sour fruits. Upon examination, an enamel defect is detected, usually round in shape. When the process is chronic, its edges are flat, and when it is acute, they are steep. Exposure to cold and chemical irritants is often painful. Average caries (caries media) . Depending on the activity of the process and age, average caries has some clinical differences. In children 1-3 years old: in most cases it is very active, but they still cannot localize their sensations and express them, so average caries is detected during preventive examinations of children by a dentist, less often by parents. A feature of the clinical course of caries in children is the so-called planar form of caries, when the process of tissue demineralization spreads faster over the surface of the tooth than in depth. Occasionally, planar, slow-moving caries does not progress without treatment, but “stabilizes.” The affected enamel is erased when chewing, the exposed dentin has a color from light yellow to dark brown, dense, shiny, painless when probing. This form is called arrested caries. It is most often found on the chewing surfaces of the first temporary molars in children 4-7 years old. The slow progression of caries in children is observed relatively rarely: carious dentin is brown, dry, and difficult to remove with an excavator in the form of scales; at the bottom of the cavity the dentin is dense and often pigmented. In preschoolers and schoolchildren, there is an intermediate course, when both decalcification and pigmentation of carious tissues are moderately expressed. Deep caries (caries profunda) In temporary and permanent teeth with incomplete root formation, this form of pathology practically does not occur. Due to the morphofunctional characteristics of dentin and pulp, deep destruction of dentin is always accompanied by pronounced reactive and dystrophic changes in the pulp. These changes, under the influence of irritations caused by the treatment of the carious cavity with a drill and medications, easily turn into inflammation and necrosis. Each case of deep destruction of tooth dentin should be thoroughly examined using clinical (response to temperature stimuli, probing, percussion, etc.), electrodiagnostic and radiological research methods. During the active course of caries in children aged 1.5-3 years, replacement dentin is practically not formed, the dentin of the bottom of the carious cavity is deeply infected, there are changes in the pulp characteristic of developing forms of chronic pulpitis or pulp necrosis, even in the absence of complaints from the child on the day of the visit doctor In the differential diagnosis of deep caries and complicated caries, it is necessary to take into account the anatomical features of the teeth. The process is most active in children aged 1-3 years, when the activity of the pulp is reduced, there is little functional ability to produce replacement dentin, and the protective properties of the pulp are minimal. The process progresses rapidly, causing in most cases complicated forms of caries. In relation to permanent teeth, the diagnosis of deep caries is justified for any activity of the process. With regard to primary teeth, this diagnosis is made with great caution, mainly in older preschool children and in cases of compensated caries. Temporary teeth are smaller than permanent teeth and their enamel layer is thinner. When determining a carious cavity, i.e. proximity of the pulp, it is necessary to take into account the group affiliation of the teeth, their size, the age of the child, and the location of the cavity. For example, on the contact surface of the lower incisors in children 2-3 years old, a cavity with a depth of 1 mm is considered deep, and in schoolchildren 12-15 years old on the chewing surface of the molars, a cavity with a depth of 3-3.5 mm can be considered medium. With active caries, not only is there no or almost no replacement dentin, but also the protective sclerosis in the dentin of the cavity bottom is weakly expressed. Dentinal tubules remain wide, the cytoplasmic processes of odontoblasts are destroyed, the tubules are filled with mixed bacterial flora, therefore, irreversible changes in the pulp of temporary teeth often occur in shallow carious cavities. Despite the fact that caries in temporary teeth develops in accordance with the same patterns as in permanent teeth, the clinic identifies a number of features in the manifestation of the main symptoms of the pathology. These features, in turn, are determined by the degree of maturity of the tooth in which caries develops, as well as risk factors predisposing to a certain localization of the carious cavity, the intensity of destruction of tooth tissue, pulp reaction, etc. As already noted, the main feature of the carious process in children is the rapid course of the pathological process. Children more often than adults experience acute, or “blooming” caries (CC), which in a short time (from several weeks to 3 months) can completely destroy the tooth crown. “Blooming” caries is an acute carious process that affects many or all erupted teeth, quickly destroys coronal tissues, often localized on surfaces that are usually not susceptible to caries, with early involvement of the dental pulp in the process. In one recent study, individuals with active CD were defined as having 5 or more new carious lesions per year. "Blooming" caries usually affects primary teeth in the order of their eruption, with the exception of temporary incisors on the lower jaw. These teeth are likely to be resistant to caries because they are in close proximity to the submandibular salivary glands, which secrete secretions, and because of the cleansing action of the tongue during pacifier sucking. The first carious lesions are usually found on the labial surface of the maxillary incisors near the gingival margin as an area of whitish decalcification or softening on the enamel surface shortly after their eruption. These lesions quickly become pigmented and acquire a light yellow color; within a short time they reach the proximal surfaces and the cutting edge of the incisors. Less commonly, areas of decalcification may initially be localized on the palatal surfaces, and in some extreme cases even near the incisal edges of the incisors. As the process progresses, it often spreads around the circumference of the tooth, leading to pathological fracture of the crown with minimal trauma. Gradually, other teeth are involved, namely the first and second primary molars and, ultimately, the canines. Blooming caries can also affect permanent teeth due to children's tendency to frequently consume cariogenic breakfasts and sugary drinks between meals. Typical “blooming” caries in adolescents is characterized by carious lesions of the buccal and lingual surfaces of molars (buccal and lingual caries), the proximal and labial surfaces of the mandibular incisors (proximal and labial caries). A specific form of “blooming” caries can develop in children and adolescents whose saliva production has significantly decreased under the influence of radiotherapy undertaken to treat cancer in the head and neck area, or due to surgical excision of tumors in the oral cavity. In such patients, fillings fall out soon after treatment, teeth are often covered with plaque, saliva is viscous and scant. Children suffering from acute dental caries have a history of acute infectious diseases, chronic concomitant diseases - rheumatism, chronic tonsillitis, etc., and a tendency to colds. A dental examination reveals caries damage to a large number of teeth, often exceeding 12-14. All groups of teeth are affected, including the canines and lower incisors, which are usually resistant to caries. As with acute caries, symmetrical teeth are often affected. Acute (“blooming”) caries is characterized by a multiplicity of carious defects (up to 3-4 defects on the crown of each affected tooth). So-called “bottle” caries develops quickly in a group of children when they are bottle-fed at night. Usually occurs in 2.5-15% of children. It is characterized by rapid damage to the anterior teeth of the upper jaw, which later spreads to the chewing teeth of both jaws. Due to late eruption, canines are less affected than first molars. “Bottle” dental caries is typical for all socio-economic groups of the population and is often an indicator of the social level of the family. The same system for the occurrence of caries with indiscriminate and prolonged breastfeeding. The cause of this pathology is prolonged exposure to a cariogenic substrate, which comes into contact with the vestibular surface of the upper anterior teeth for 8 hours. In addition, at night there is a low level of salivation and a reduced buffer capacity of saliva. The peculiarity of the course of acute caries manifests itself at different depths of the defect. Thus, initial caries in its most acute form is characterized by the formation of a dirty gray spot (spots) or area(s) of enamel clouding with unclear contours. Such lesions are usually detected by a painful reaction when exposed to mechanical, temperature or chemical stimuli. In case of superficial caries, when the defect is localized in the enamel or reaches the enamel-dentin junction, the enamel appears heterogeneous, fragile, brittle; such defects are usually extensive, with uneven edges, as the process quickly spreads in breadth, along the plane. This picture is especially often observed in temporary teeth, with a characteristic cervical localization, encircling the neck of the tooth. In such cases they talk about “circular” caries . In the most acute cases of superficial caries, there may be complaints of pain associated with eating sweet, sour, and salty foods. When such a defect is localized on the approximal surface, as with other forms of caries, complaints about food getting stuck come to the fore. In the most acute course of moderate caries, a cavity (cavities) with uneven contours, undermined edges, formed by brittle whitish enamel is discovered. Usually there are complaints of pain from chemical, temperature irritants, and when localized on the proximal surface - of food getting stuck. In the most acute cases of moderate caries, there may be complaints not only about the effects of cold. Sometimes pain occurs from hot foods, which may be due to the involvement of the pulp in the chronic inflammatory process. Deep damage to primary teeth in the most acute course of caries has to be diagnosed extremely rarely, since the progression of the process is complicated relatively early by inflammation of the pulp. A detailed diagnosis, reflecting both the depth of the lesion and the nature of the course of caries, is the basis for complex treatment and is of great importance for the practical use of preventive means. Complications of caries Without timely and proper treatment, caries can develop into more severe forms of tooth disease (pulpitis, periodontitis) and lead to tooth loss.
Features of caries resistance
Caries resistance includes several main properties of enamel:
- Degree of acid resistance;
- Microhardness;
- Permeability.
The development of caries depends on the following factors:
- On the degree of aggressiveness of various factors;
- From the condition of the enamel.
It follows from this that during the pathogenesis of the development of dental caries, the main role is played by the decalcifying effect of organic acids of microbial origin. It is believed that the degree of resistance of the enamel structure to acid demineralization directly reflects all the properties of resistance to carious lesions.
Caries resistance – resistance of dental tissues to carious effects. Caries resistance includes not only the condition of the tooth tissues, but also the condition of the oral cavity, oral fluid, and the condition of the body as a whole.
Therefore, resistance to dissolution is considered the most important quality of enamel, which allows maintaining the integrity of the structural and functional appearance in the presence of acid-forming bacteria inside the oral cavity and plaque. As a result of numerous studies, it was revealed that the degree of solubility of enamel tissue on different surfaces differs. The gingival areas of all teeth have the highest degree of solubility. This is due to the fact that it is in these places that there is a reduced level of mineralization. According to V.K. Leontiev, which was put forward in 1977, various factors may underlie the heterogeneous structure of enamel:
- Differences in mineralization of different parts of the tooth;
- The presence of various defects in the structure of the crystalline lattice;
- Individual qualities of interactions between the protein matrix and the mineral phase and other reasons.
Professor Okushko V.R. in 1984 determined that the acid resistance of enamel is associated with the properties of centrifugal permeability, due to which cerebrospinal fluid is released on the surface of the enamel. As a result of a series of experiments, it was found that by regulating the speed of movement of the cerebrospinal fluid, it is possible to change the acid resistance, and therefore the resistance of teeth to caries. In general, acid resistance and caries resistance depend on the properties of dental tissue and enamel. These factors are provided by the functional and structural features of the tooth structure.
Material and methods
To achieve the stated goal of the study at the Department of Pediatric Dentistry with Orthodontics at VSMU named after. N.N. Burdenko, as well as on the basis of the state educational institution of the Voronezh region “Boarding School No. 1 for orphans and children left without parental care,” a prospective cohort examination of the oral cavity of 138 children was conducted, of which 27 (19.6%) were aged 7-10 years old, 39 (28.3%) children aged 10 to 14 years and 72 (52.2%) adolescents aged 14-16 years old, living in the same type of environmental conditions of Voronezh, receiving the same nutrition, having intact dental row, foci of initial demineralization of enamel, as well as carious cavities of teeth.
In accordance with the purpose of assessing the effect of a fluoride-containing coating with tricalcium phosphate, a study was carried out on 45 patients with high caries resistance, without carious cavities and foci of initial demineralization of teeth, covered with a small amount of soft plaque, who made up the 1st group, 62 patients with sufficient average caries resistance, having foci of initial demineralization and primary foci of destruction of enamel and cement, as well as carious lesions of only chewing teeth, the absence of pulpless teeth, the presence of a small amount of soft plaque, according to the surveyed - new carious cavities did not appear every year - group 2 and 31 patients with reduced average caries resistance, having carious cavities in the chewing frontal teeth, the presence of several cavities in one tooth, the presence of pulpless teeth, a significant amount of plaque on the teeth, according to the surveyed, the annual appearance of new carious cavities, the rapid “loss out” of fillings within 1-2 years — 3rd group [4].
All groups were divided into 2 subgroups to evaluate the effectiveness of treatment with the use of therapeutic and prophylactic fluoride-containing coating with tricalcium phosphate and without the use of this product, but using individual oral hygiene products.
In laboratory conditions, 10 extracted teeth of patients aged 7 to 16 years were examined for orthodontic indications. Intact teeth were subjected to special research methods: scanning electron microscopy, X-ray spectral microchemical and energy dispersive analysis.
The objectification of clinical data was facilitated by the use of laboratory research methods, the results of which were recorded at certain time points - a clinical examination after 6 months. When carrying out the study, ethical principles were observed, written consent was obtained from the administration of boarding school No. 1, as well as the Department of Education, Science and Youth Policy of the Voronezh Region for the examination and implementation of preventive measures.
Dental fluoride material Clinpro White Vamish is a complex remineralizing fluoride coating with tricalcium phosphate, containing fluoride in the form of 5% sodium fluoride and the innovative ingredient tricalcium phosphate with fumaric acid, which does not allow it to react with the fluoride inside the package until the product is applied on the teeth. The coating is an alcohol solution of a modified resin. Clinpro White Vamish is sweetened with xylitol and has a pleasant minty flavor. The product is supplied in packs containing a single dose of 0.5 ml. Each 0.5 ml dose contains 25 mg of sodium fluoride, which is equivalent to 11.3 mg of fluoride ion (22,600 ppm fluoride).
Visible and accessible tooth surfaces were assessed by visual inspection in good light using a dental mirror and probe, and vital staining of the teeth with a 2% aqueous solution of methylene blue. To assess the hygienic state of the oral cavity, the expanded hygienic index according to Fedorov-Volodkina was determined; the plaque index was assessed using a probe from four surfaces without staining with preliminary drying with an air jet.
To assess the rate of reduction in caries growth, we proposed an index of clinical and laboratory assessment of the resistance of hard tissues of teeth (ICLORZ) as a more sensitive assessment result to initial changes in enamel, determined in combination with X-ray diagnostics, electrometric diagnostics and light-induced fluorescence, in contrast to the CPZ index (Table 14].
Table 1. A set of methods for clinical assessment of the condition of hard dental tissues Note. * — R0 — no signs of destruction; R1 - demineralization of the outer half of the enamel in the affected area; R2 - demineralization of the entire enamel layer in the affected area; R3 - demineralization of enamel and the outer half of dentin in the affected area; R4 - demineralization of enamel and deep layers of dentin in the affected area.
If you have filled teeth, the score is given depending on the electrometric resistance at the border of the filling and the hard tissues of the tooth.
The index was calculated as the ratio of the sum of points obtained to the total number of examined teeth in the oral cavity.
Intraoral X-ray diagnostics were carried out using a dental apparatus de Götzen srl (Italy) sistema radiografico per diagnosi intraorale - x-ray system, electrometric diagnostics of hard dental tissues were carried out using a DentEst apparatus, Russia. The measurements were carried out at a constant voltage of 4.26 V, and the results obtained in microamperes were recalculated to the resistance value of the hard dental tissues under study, taking into account the factor of the full maturation of the enamel. The assessment of light-induced fluorescence of hard dental tissues was carried out using an LED activator LED active 05, Russia, at a wavelength of 530 nm, illumination of 100,000 lux, and also a wavelength of 625 nm at a radiation power density of 140 mW/cm².
To determine the microcrystallization index of oral fluid on a drop of this liquid, the ratio of the number of ocular grid points projected on the crystals to the total number of ocular grid points projected throughout the entire drop of oral fluid was calculated.
The buffer capacity of saliva was determined using the CRT buffer kit, and the acidity of the oral fluid was determined using the I-500 basic ion meter.
Scanning electron microscopy and X-ray spectral microchemical analysis (XMA) of 10 extracted teeth were assessed using a low-vacuum scanning electron microscope model JEOL JSM-6380LV (Japan). The distribution of chemical elements in the area of the interface of the fluorine-containing coating and tricalcium phosphate with tooth tissues was studied by micro-X-ray spectral mapping of transverse chips of teeth using an INCA-250 energy dispersive analysis (EDA) system. The planar distribution of chemical elements was assessed by coloring the X-ray image with different colors specified by the operator.
Statistical analysis of the materials obtained as a result of the study was carried out using the mathematical software package Statistica 6. X, Biostat, which is an integrated environment for statistical analysis and data processing.
Insufficient mineralization of enamel as a factor predisposing to the development of dental caries
Tooth enamel
- highly mineralized tissue of a living organism: the content of mineral salts in it is 95%, organic substances - only 1.2%, water - 3.8%.
The morphological structure and mineral composition of enamel are not constant and can change under the influence of various factors: age, characteristics of mineral metabolism in the body, composition and properties of saliva, diet, etc.
There are two phases in enamel mineralization: primary mineralization, which occurs during the intramaxillary period of tooth development, and secondary mineralization, or “maturation” of the enamel, which continues for 3-5 years after teeth eruption.
By “maturation” we mean an increase in the content of calcium, fluorine, phosphorus and other mineral components and an improvement in the structure of the enamel. The processes of “maturation” of enamel occur especially intensively in the first 12 months after the eruption of a tooth in the oral cavity.
Before tooth eruption, the developing enamel is in close contact with blood serum and tissue fluid and is mineralized by the substances contained in them. The enamel matrix of an unerupted tooth is similar in structure to a mature one. However, it differs from mature ones in its higher content of organic substances and water and a smaller amount of mineral components - about 25 - 30%.
The combination of these formations forms the microporosity of the enamel.
The total volume of pores in newly erupted enamel ranges from 3 to 6%. Features of the chemical composition and structure of immature enamel, combined with microporosity, determine its low caries resistance, high solubility and permeability.
Numerous clinical observations indicate that caries develops most intensively in the first years after tooth eruption.
, which coincides with the period of immature enamel.
Complete mineralization of enamel
after tooth eruption occurs due to the supply of minerals from saliva.
Mineral components can be introduced into the enamel purposefully
in the form of remineralizing solutions, fluoride-containing gels, varnishes and other means of local prevention. Mineralization is ensured by a high degree of permeability of the enamel of immature teeth, which has important physiological significance during this period.
As the enamel matures, the homogeneity of its structure increases, the surface relief smoothes, and the volume of microspaces decreases to 0.1-0.2%, which leads to an increase in the density of the enamel. The amount of water in the enamel decreases. Due to the entry of fluoride ions into the enamel, its resistance to caries increases.
Fluoride plays an important role in the maturation of enamel.
the amount of which gradually increases after tooth eruption. Its inclusion from saliva into enamel has been proven. Fluoride regulates the absorption of calcium by the hard tissues of the tooth. The rate of mineralization increases significantly in the presence of fluoride. Even with such a low fluorine concentration as 1:1000, the rate of mineralization increases by 3-5 times.
Fluoride has the most pronounced anti-caries effect when it is supplied during the period of mineralization and maturation of enamel. Additional introduction of fluoride reduces the solubility of enamel and increases its microhardness. Thus, information about the structure and physiological properties of the enamel of immature teeth allows us to formulate the task of local prevention of dental caries - this is to ensure the physiological process of maturation of hard tooth tissues and stimulate it, if necessary, in order to form caries-resistant enamel.
Relevance
. Currently known methods of preventing dental caries can effectively combat this disease. However, in order to select the most effective means of caries prevention, it is necessary first of all to clarify the schemes and indications for their use. This is closely related to the possibility of dynamically determining the individual resistance of dental hard tissues to caries, depending on the state of the body and treatment and preventive measures.
Purpose of the study
— to compare the effectiveness of existing methods for assessing caries resistance to improve control of enamel condition and the possibility of early diagnosis of caries and determining the effectiveness of prevention methods.
Material and methods.
The study included 40 patients aged 32 to 45 years, with an average age of 35 years. Patients were divided into 2 groups, randomized by gender, age and level of caries resistance. All patients underwent a clinical examination of the mouth with determination of the OHI-S index. To assess the condition of the enamel, the level of caries resistance was determined using the V.B. method. Nedoseko (V.B. Nedoseko, 1988) and performed an acid biopsy (V.K. Leontyev, V.A. Distel, 1975 modified by M.Yu. Zhitkova, 2000) with the calculation of the calcium-phosphorus ratio (Ca/P coefficient) , as well as the KOSRE test (V.K. Leontyev, T.L. Redinova, G.D. Ovrutsky, 1988), reflecting the rate of enamel mineralization. Patients in both groups received instruction in oral hygiene, dental treatment according to indications, and professional hygiene. Those observed in the main group were additionally prescribed the remineralizing gel Tus Mousse, which they rubbed into the enamel of their teeth 2 times a day, morning and evening, for 30 days. After 1 month, an acid biopsy was repeated in both groups to assess the condition of the enamel. To determine the correspondence between the two methods, assessing caries resistance (V.B. Nedoseko method, acid biopsy method), a correlation analysis of the obtained indicators was carried out.
Results.
The level of resistance in each group was not higher than moderate, the level of intensity of caries KPU was 15, the initial value of the Ca/P coefficient was 0.29.
The correlation coefficient between the level of caries resistance and the Ca/P ratio was quite high and amounted to 0.72. Recovery of the focus of demineralization after acid biopsy in the control group occurred after 25±5 days, in the main group - after 10±2 days ( p
<0.01), indicating a higher rate of remineralization with the drug used.
By the end of the month of observation, the Ca/P coefficient increased in the control group to 0.32, and in the main group against the background of the use of Tus Mouss gel - to 0.39 ( p
= 0.19 and
p
= 0.03 relative to the initial level, respectively). The Ca/P coefficient in the main group after remineralizing therapy was less correlated with the level of caries resistance. In the control group, the correlation coefficient was 0.63, in the main group - 0.32. This is explained by the fact that in the control group after a month the level of mineralization (according to V.B. Nedoseko) differed little from the initial one. In the main one, enamel resistance increased by 22% compared to the primary data.
Conclusion.
The acid biopsy method allows you to record changes in the condition of the enamel in a shorter time. Determination of the level of caries resistance using the V.B. method. Insufficient and indicators of acid biopsy of enamel are comparable, however, enamel biopsy allows not only to predict the development of caries, but also to quickly monitor the dynamics of caries resistance, which is necessary for studying different schemes and methods of prevention, choosing the most effective and economical, depending on the individual characteristics of patients.
