DEVITAL METHODS OF TREATMENT
Essence of method - removal of coronar or coronar and root pulp with its preliminary devitalization. Devitalization - is the destruction of practically all structures of the tissue of pulp with the complete disturbance of its function, including of its painful sensitivity.
Devitalization is used in such cases if we impossible use the vital method of treatment. This:
• the sensitization of organism to the anesthetics,
• the fear of the patient of different injections,
• the ineffectiveness of the uninjection methods of anesthetization,
• the failures of vital method (insufficient anesthetization on the stages of the carrying out of vital method);
• with the expressed forms of the diseases of oral cavity - inflammatory diseases of oral mucosa;
• in the persons, compromised by general severe diseases.
Most frequently for devitalization of pulp use the preparations of arsenous acid and paraformaldehyde. The mechanism of the action of arsenous acid on the pulp is many-sided. Being protoplasmic poison, arsenous acid anhydride, first of all, acts on the oxidizing enzymes of pulp, it leads to the local disturbance of tissue respiration and the phenomena of hypoxia.
Oxidase loses its specific functions as the enzyme of oxidation under the action of the smallest quantity of arsenic. Furthermore, arsenic blocks the thymol compounds, which fulfill the functions of the coenzymes of respiration. The dilatation of blood vessels is noted in response to the primary irritation, especially capillaries, thrombosis is developed, the hemorrhages appear, which depend on a change in the walls of vessels. Edema leads to the compression of the tissue of pulp. The nerve fibers of pulp undergo the grainy disintegration of myelinic shells, knotty swelling and the disintegration of axial cylinder. Varicosity of nerve fiber is replaced by its death. Changes in all groups of the cellular elements of pulp is reduced to the phenomena of karyorehexis and loss of cells, the first of all odontoblasts.
The depth of the defeat of pulp is located in the direct coupling with the period of action and the dosage of arsenous acid. In the place of the application of arsenous acid the picture of the death of all elements of coronar pulp is observed.
The prolonged effect of arsenous acid can cause toxic changes in the periodontium and necrosis of the surrounding tissues.
Arsenous acid (anhydride) for devitalization of pulp is used as paste. For the composition of paste to the acid the medicinal substances are added, which possess the anesthetizing, antiseptic properties, and also the drugs, which retard the diffusion of arsenic in the tissue of pulp and which thus weaken its toxic action. For this purpose novocaine, carbolic acid, tannin, iodoform, clove, camphor oil, glycerin are used. Taking into account that the fact that arsenous acid is strong protoplasmic poison, it is necessary to adhere dosing paste depending on the size of tooth, state of pulp, age of patient and selection of the method of treatment of pulpitis.
For devitalization of pulp it is sufficient 0,0002-0,0004 g of arsenous acid, the recommended duration of action in the single-rooted teeth - 24 h, in the multirooted - 48 h.
At present arsenious paste is produced dosed, in the form the granules of different color depending on the necessary periods of the imposition of paste (green, dark-blue and other). Into the composition of arsenious paste vehicle is sometimes loaded in the form of the small filaments of different color (or cotton) for facilitating of dosage (Pulparsen, Causticin and others).
Paraformaldehyde paste possesses less toxic properties. Into its composition as the basic acting agent the paraformaldehyde is entered - product of the polymerization of formaldehyde, whose fumes have the strong bactericidal, dehydrating and mummifying action, but in the high concentrations it is caused the necrosis of tissues. At a temperature of body it occurs slow depolymerization with the gradual elimination of the monomer (formaldehyde), which draws slow nekrotizition of pulp.
The high concentrations of paraformaldehyde under its prolonged effect cause the necrosis of tissues. The mechanism of the action of formaldehyde consists of its influence on the endothelium of capillaries, expansion of blood vessels, stasis of the blood in them and gradual mummification of the tissue of pulp, which is converted into the dry grey tension bar.
Preparation renders less toxic action on the tissue of periodontium.
Into the composition of paste, besides paraformaldehyde, it is entered the anesthetic (anesthesine, Trimecaine), clove oil (eugenol).
The paste is superimposed in a quantity, which according to the size answers the head of spherical bur of № 9 (this into twice more than arsenious). Most frequently devitalization of pulp begins in 6-7 days in the single-root teeth and in 10-14 days - in the multirooted. The period of the imposition of paste depends also on the nature of the inflammation of the pulp of tooth and selection of the method of treatment, i.e., the partial or total exclusion of inflammatory pulp.
The risk of overdose and toxic influence to paraform on the surrounding tissues is minimum, therefore it uses even in the temporary teeth.
Paraformaldehyde paste acts 7-14 days, but it does not appear complications even in 4 weeks.
Different pastes are presently produced on the basis of paraformaldehyde: “Parapasta” (Chema, Polfa), “Depulpin” (VOCO), “Devipulp”, “Toxovit”, “Necronerv” and other.
The periods of the imposition of paste depend also on the nature of the inflammation of the pulp of tooth and selection of the method of treatment, i.e., the partial or complete removal of the inflamed pulp. The methods of devitalization of pulp are in the literature described as classical:
two-session method - amputation,
three-session method - extirpation.
Devital amputation
Displays:
root canals are not passed from their obliteration;
root canals are hard-patulous from curvature of roots.
Consciously this method uses only in cases when:
the patient has grave general condition of organism (after the myocardial infarction, heavy operations);
in mentally sick people;
with the impossibility of access to the junctions of root canals because of the difficult opening of mouth;
in the third molar, when carious cavities are placed distally;
in the patients with thromboembolic disease;
during the treatment of pulpitis of temporary teeth.
In all other cases it is necessary to accomplish extirpation of pulp.
Contra-indications: pulpitis in permanent single-root teeth with a good general state of organism.
Method of devital amputation
This method is counted on 2 visits.
First visit.
First stage. Toilet of the oral cavity. Premedication (using the tranquilizer and analgesic properties (in the absence contra-indications).
Second stage. Preparation of carious cavity. As a result of the acute painfullness all manipulations through the preparation of carious cavity, using application anesthetization, are conducted maximally carefully, without causing suffering to patient.
After the opening of carious cavity the softened dentine is removaled step by step, at first from the walls of cavity by sharp excavator or by spherical bur, and then from the bottom of carious cavity, periodically using application anesthetic. In the cases of acute diffuse pulpitis it is necessary to compulsorily open the cavity of tooth at least at one point. This connection of the cavity of tooth with the carious removes or decreases the intrapulpal pressure, create conditions for the output of exudate from the pulp. This also ensures the penetration of the devital agent into the pulp. The best of all it is made in the projection of the horn of pulp by spherical bur of large size in order it is not fallen through into the cavity of tooth and it is not traumatized pulp. Then carious cavity carefully washes in the warm solution of antiseptic, and it is dried with cotton ball.
Third stage. Imposition of the devital paste. The devital paste is collected the necessary quantity: arsenious, usually - the volume of pin head (approximately 0,0006-0,0008 g. of arsenous acid anhydride); paraformaldegid - it is twice more. After placing the selected quantity of paste to the tip of the probe or excavator, it is entered in a carious cavity and place near the perforating opening and carefully it is moved to the opened horn of pulp with cotton ball.
Acting on the pulp, the devital paste irritates it, strengthens exudation, increasing a feeling of pain. For its decrease paste is covered with the dry cotton ball, which absorbs the surplus of exudate from the pulp, and thus it is decreased intra-pulpal pressure. For this purpose cotton ball can be additionally slightly moistened with the solution of anesthetic.
Carious cavity is hermetically filled with paste from the artificial aqueous dentine. It is mixed to the like as sour-cream consistency and carefully, without pressure, it is put into the cavity. Dentine-paste is not used, as in the case of its introduction it presses to the pulp, creates compression, thus causing pain attack. In certain cases, for example, with the presence of large carious cavity of the IV, V classes, which deeply penetrates under the gingival edge, bandage from the artificial dentine does not ensure a sufficient hermetic sealing of cavity. There is a danger of the leaking out of arsenous acid anhydride from cavity and appearance of the necrosis of those being located near soft tissues (gums, cheek, tongue). In that case it should be filled carious cavity with the arsenious paste with that liquidly mixed phosphate-cement or it is led out it on the oclussional surface, and precervical cavity is filled with dentine.
It is necessary to warn patient that after the imposition of the devital paste it can be arisen the pain in the tooth, which continues several hours. For decreasing the painful sensitivity patient is prescribed the anaesthetizing medicines. Arsenious paste as the devital agent lay on into the single-rooted teeth on 24 h, into the multirooted - to 48 h, paraformaldegid pastes - on 7-10 days. Patient is compulsorily warned about the necessity for further treatment of tooth for the appointed time, since the neglect of diagram and of the time of treatment from the side of patient it can be caused different complications and lead to the loss of tooth.
Second visit.
If deviations are not revealed from anamnesis, clinical examination of tooth and surrounding tissues, the following stages of treatment are carried out.
1. Removal of bandage.
2. Complete preparation of carious cavity.
3. Opening of the cavity of tooth.
4. Amputation of coronar pulp by sharp excavator or by spherical bur.
5. Opening junctions of root canals and the resection of pulp from junctions of root canals with spear-shaped burs or with bur of Gates-Glidden.
6. Antiseptic processing of the stump of pulp and cavity of tooth - irrigation with the solution of nitrofurazone 1:1000, with 1% solution of chlorhexidine and others.
7. Drying of cavity of tooth and coverage of the stump of pulp with the therapeutic paste, character of which depends on the form of pulpitis, age and state of patient.
8. Fill tooth with temporary, then permanent filling.
During the amputation of pulp with the devital method of treatment for coverage of its stump different pastes are used.
Sufficiently conditionally it is possible to divide them into three groups: mummifying, metaplasing and odontotropning.
Mummifying pastes. They cause the mummification of the stump of pulp, and thus they prevent further spread of inflammatory process in the pulp. As a rule, they rapidly penetrate the pulp, causing the turning of the proteins of its tissue, they appear to a sufficient degree of depot of antiseptics and they do not irritate periodontium. This group includes the resorcin-formalin paste, prepared ex tempore, “Kreodent” (Russia), “Foredent” (Czech Republic) and other.
Metaplasing pastes. The transformation of the inflamed tissue of root pulp into the osteoid tissue is the basic mechanism of their action. The most common representatives of the metaplasing pastes are thymol, iodoformthymolovaya, trioksimetilenovaya pastes.
Odontotropning pastes. Fairly often dentists use pastes of odontotropning action. They are most widely known of them zinc -eugenolovaya, eugenol-thymolovaya, paste with sulfanilamides.
The effectiveness of the treatment of pulpitis with the amputation method to a considerable degree depends on the correct selection of indications to this method, the correctness of conducting the procedure of treatment and selection of coverage pastes of the stump of pulp. For example, gross mistake with the devital amputation is application for coverage of the pulp of the pastes of the so-called biological action (with the antibiotics, enzymes and others). They are counted on the keeping of the vital activity of pulp, while with the devital method pulp is considerably affected by the devital medicines and it is not capable of restoring its vital activity. At present the devital amputation method of treatment does not find wide application in the practice both in connection with the narrow indications and in connection with the frequent and serious complications.
DEVITAL EXTIRPATION OF PULP
Devital extirpation - this is the method of the complete removal of pulp after its preliminary devitalization.
Indications:
•with the intolerance of the anesthetics as a result of the sensitization of organism to them;
• in the persons, it is older than 50 years;
• with the heavy somatical pathology;
• with the expressed forms of the diseases of the oral cavity - inflammatory diseases of the oral mucosa;
• when a patient is afraid of various injections;
• with the ineffectiveness of the injection methods of anesthetization;
• with the failures of vital method.
Devital extirpation is carried out in two visits: at the first -- pulp is devitalization, at the second – pulp is removaled complete - extirpation.
First visit.
Toilet of the oral cavity, anesthetization (application, the prescribing of analgesics, sedative medicines, audioanaesthesia, etc).
Partial preparation of carious cavity, the opening of the cavity of tooth, the imposition of the devital paste and air-tight bandage. Because of acute painfulness of pulp the removal of the softened dentine can be carried out by sharp excavator. The preparation of carious cavity conduct partial for the purpose of providing of a good access to the pulp and creation of conditions for the fixation of air-tight bandage.
Pulp cavity is perforated.
Signs of the discovery the arch of pulp cavity:
pinhole;
the point of bloody fluid.
carious cavity carefully washes in the warm solution of antiseptic, if it is necessary, for the stopping of pain the anesthetic is introduced on the cotton ball. The draining of the exudate through the perforating opening also decreases the pain;
After the stopping of pain in the section of the revealed cavity of tooth with probe the devital paste is brought, then to it the cotton tampon is put in, slightly moistened by anesthetic, and oral cavity is filled with the air-tight bandage (artificial dentine on the water), which it is put in carefully without the pressure. During the imposition of arsenious paste special attention should be focused on hermetic filling of carious cavity, so that the arsenous acid would not leak out between bandage and wall of carious cavity. With the nonhermetically superimposed bandage the arsenous acid can cause toxic papillitis or localized parodontitis. Paste is superimposed on 24 h in the single-root teeth and 48 h -- in the multirooted teeth.
Second visit.
After interview and objective examination of patient air-tight bandage is removaled and the final preparation of carious cavity is conducted.
Opening of the cavity of tooth. The arch of the cavity of tooth is cut off by fissural bur, the walls of carious cavity must pass into the walls of the cavity of tooth.
Amputation of the pulp of tooth. The amputation of pulp is carried out with sharp excavator or spherical bur in the premolars and the molars. The correctly carried out amputation provides a good survey of the operating field: the junctions of root canals with the red pulp located in them must be visible.
Opening junctions of root canals and the resection of pulp from junctions of root canals with spear-shaped burs or with bur of Gates-Glidden.
with pulp extractor it is extirpation of pulp. Before this it is brought 1 -2 drops of antiseptic to junctions of root canal (or it is moistened pulp extractor with it), it is selected pulp extractor of the proper size. It is slowly brought pulp extractor and is moved it along the wall of root canal to the apex (until it is feld the sensation of light resistance), by corkscrew-shaped motion, returning to 1 -2 turns around the axis, and it is taken out pulp extractor together with the coiled on it the pulp. If pulp was not taken out immediately, procedure is repeated several times.
In the narrow root canals the pulp can be destroyed by the K - Reamer. This method of the extirpation of pulp creates the incised wound, but pulp extractor leaves avulsed (lacerated) wound with the large area of damage;
narrow canals it is enlarged on width of 2-3 sizes of Reamers;
walls of root canals are smoothed out, canals is made cone-like form, using sequentially endodontic instruments;
in parallel canals are processed by the preparations, which contain EDTA, which help to enlarge them and to degrease them;
canals are washed with antisepsis, in particular, with 3-5% solution of hypochloride of sodium, which can be connected with 3% solution of hydrogen peroxide;
canals are dried with dry wadded turundae, by paper pins;
canals are filled to the physiological apex, which corresponds to the level of cement-dentine-canal connection, which is placed at a distance of 1-1,5 mm from the opening of the apex of root. In this case in the zone between the anatomical and physiological openings of the apex of root it is formed the osteoid tissue, which will reliably divide the root cavity of tooth and periodontium;
after filling of canals it is necessary to make control X-ray examination in order to be convinced as the filling;
further it is made isolated liner (in order to isolate root filling material from a permanent filling) and a constant filling. If root sealing material gives solidification shrinkage, then in the first visit it is better to put temporary filling, and the secondly (after the shrinkage of root sealing) - to replace it by the permanent.