RU2282417C1 - Method for restoring central mandibular incisors with completely failing crown part by applying reinforcing reticularly composite pin - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: method involves preliminarily applying endodontic root treatment, widening root canal with its conicity and direction being taken into consideration. Internal root canal and crown part surface of the incisor is reinforced with pin. The pin has lingual and vestibular reinforcement members fixable in turn in the root canal. The reinforcement members are manufactured from gold-plated metal gauze corresponding to shape and sizes of the surfaces under reinforcement. Root portion length is selected to be equal to 1/3 of root canal length in lingual member and to 1/2 of root canal length in the case of vestibular member. Height of the lingual member above the root is selected to be equal to the lingual surface height of the crown part at tubercle level. The lingual and vestibular members are fixed in root canal allowing their partial overlap with longitudinal rigidity ribs being formed on the same side with approximal surfaces of the crown part. After being reinforced, the crown part is restored to its anatomical shape by applying composite materials.

EFFECT: sparing root canal treatment; high strength and uniform load distribution in chewing.

Description

The invention relates to the field of dentistry and can be used to restore the completely destroyed crown part of the central lower incisor, including in the event of its destruction below the level of the gums.

The central lower incisor is the smallest in size from the entire group of anterior teeth. The incisor has a chisel shape with a tooth tubercle and a slightly concave relief on the lingual surface, a narrow root canal and thin walls of the crown part.

As you know, the teeth of the lower jaw are tilted by crowns inward, and roots outward. The approximate surfaces of the teeth of the lower jaw are converging (converging) towards the tongue. In this case, the pressure falling on a tooth extends not only along its roots to the alveolar part, but also redistributes through interdental contacts to adjacent teeth.

Thus, the teeth of the lower jaw receive additional stability due to the features of the slope and shape of the crowns.

The prior art method of restoration of the front groups of teeth, including the central lower incisor, according to the patent of the Russian Federation No. 2238698 of 02/13/2003.

The durability of the restoration during the implementation of the known method is achieved by reinforcing the root and crown parts of the restored cutter by means of a mesh-adhesive pin. The crown part of the known pin is a grid, the width of which corresponds to the width of the defect of the crown part of the tooth, and the root part of the pin is twisted wires from the same mesh. The root part of the pin is fixed in the root canal, and the transition from the root to the crown part of the pin in the form of a neck is fixed in the cavity of the groove made on the base of the root. The holding force arising at the same time ensures the stability and strength of the fixation of the pin, and therefore, the strength and durability of the restoration as a whole.

However, in the case of natural separation of the anterior teeth of the lower jaw or in the case of loss of a number of anterior teeth of the lower jaw, restoration of the crown part of the incisor in a known manner may not be effective. A deviation of the restored incisor inward is likely, since in the absence of natural support from the adjacent teeth, the indicated holding force may not be enough to counteract the horizontal component of the functional load. There is a risk of fracture of the incisor in the horizontal direction.

In case of destruction of the incisor below the level of the gum or in the case of repeated restoration of its crown part, the use of the known method is also contraindicated due to a significant loss of the dentinal mass of the root.

The inventive method of restoration aims to restore the function of the central lower incisor, including in these clinical situations.

The problem is solved by simultaneously reinforcing the most vulnerable surfaces of the incisor in terms of the functional load: the root canal, cervical region, vestibular and lingual surfaces and the cutting edge of the crown part.

Reinforcement is carried out using a mesh-composite pin. The inventive pin consists of sequentially fixed in the root canal of the lingual and vestibular elements, pre-formed from a gilded metal mesh in accordance with the size and shape of the reinforced surfaces of the cutter.

A mesh-composite pin fixed in the root channel has a conical surface with a taper corresponding to the taper of the root channel. In the crown part, the surface of the pin is elongated in the media-distal direction and acquire a shape corresponding to the shape of the reinforced surfaces of the crown part. In the root canal, the pin is set to a depth equal to 1/2 the length of the root canal. Moreover, in the crown part, the lingual element of the pin is fixed at the level of the tubercle, and the vestibular element is located 1 mm below the level of the cutting edge. The surfaces of the lingual and vestibular elements during fixation partially overlap each other with the formation of longitudinal stiffeners along each of the approximate surfaces of the incisor.

The advantages of using the claimed mesh-composite pin are manifested:

- in the uniform distribution of the load on the walls of the root canal;

- in reducing the wedging effect on the root;

- in ensuring a tight fit of the root part of the elements of the mesh-composite pin to the surface of the root channel due to the elastic properties of the mesh and the ability to remove excess glass-ionomer cement through its cells;

- to simplify the formation and fixation of the grid-composite pin, consisting of two separate elements - vestibular and lingual; to increase the strength of restoration due to hardening of the vestibular and lingual (up to the tubercle level) surfaces of the restored crown part of the incisor;

- to increase the strength of the restoration due to the additional reinforcement of the approximate surfaces of the cutter with the formation of stiffeners.

The technical result achieved by the implementation of the proposed method is to sparingly develop the root canal, due to the design features of the mesh-composite pin, as well as to ensure strong and durable restoration of the central lower incisor, including in these clinical situations.

SUMMARY OF THE INVENTION

When preparing a tooth for restoration, the color of the future restoration is determined on the VITA scale. The root canal should be sealed to the apex and should not have periapical changes.

In case of destruction of the crown part of the lower incisor below the gum level, the walls of the root base are previously restored with composite materials 1 mm above the gum level with a thickness of 1 mm.

The sealed channel is expanded, forming a cavity to a depth of 1/2 of its length, taking into account the taper and direction of the channel. During the development process, the channel walls must retain a thickness of at least 0.5 mm.

To reinforce the root and crown parts of the lower incisor in the complete absence of its crown part, a reinforcing mesh-composite pin is used, which consists of:

reinforcing vestibular mesh element;

reinforcing lingual mesh element.

The manufacture of reinforcing mesh-composite pin

For the manufacture of a reinforcing mesh-composite pin, a gold-plated metal mesh used in dentistry is used, from which two rectangular blanks are cut out to form the constituent pin of the vestibular and lingual elements. The length of the grid rectangle for the vestibular element is chosen equal to the sum 1/2 of the length of the root canal and the height of the crown part of the incisor, and the width of this rectangle is equal to the sum of the maximum width of the vestibular and the width of the approximate surfaces.

The length of the grid rectangle for the lingual element is chosen equal to 1/3 of the length of the root canal and the height of the crown part of the incisor at the level of the tubercle, and the width of this rectangle is equal to the sum of the maximum width of the lingual surface of the lower incisor at the level of the tubercle and the width of its approximate surface. At each of the grid rectangles, the corners are cut symmetrically from the side placed in the root canal. The length of the cut is 1/2 or 1/3 of the length of the root canal, respectively, for the vestibular and lingual elements of the pin. As a result, the width of the grid rectangle from the side of the cut is not more than half of the channel perimeter. On the cut side, the mesh is conical in shape taking into account the taper of the developed root canal, thus forming the root part of each of the component elements of the pin. And the rest of the grid of each of the elements is shaped in accordance with the shape of the reinforced surfaces of the coronal part: vestibular with the transition to the approximate and lingual (at the level of the tubercle) also with the transition to the approximate.

Perform the fitting and adjustment of the formed vestibular and lingual elements of the mesh-composite pin.

After fitting and correction, the elements are removed. Next, acid and adhesive treatment of the root canal is carried out for subsequent fixation of the reinforcing mesh-composite pin and restoration of the missing crown part of the lower incisor using composite material.

Fixing the reinforcing mesh-composite pin

First, a reinforcing lingual mesh element is fixed in the prepared root canal. To do this, glass ionomer cement is applied in a thin layer to the inner lingual surface of the root canal. A reinforcing lingual mesh element is placed in the root canal to a depth of 1/3 of the length of the root canal, press it against the inner lingual surface of the root canal and polymerization is carried out. Using a reinforcing lingual mesh element, the lingual surface of the root canal is reinforced. The rest - the root part of the fixed lingual mesh element - is located in the crown of the tooth and, after complete restoration of the crown, provides reinforcement of its lingual surface, including the tubercle, with a transition to the approximate surface. Next, they begin to fix the reinforcing vestibular mesh element. To do this, the root canal is filled with stelionomer cement and a reinforcing vestibular mesh element is installed in the root canal to a depth of 1/2 the length of the root canal, polymerization is carried out. The part of the fixed vestibular element located in the coronal part is the root-root part of the vestibular element 1-2 mm below the level of the incisal edge of the incisor.

When installing the vestibular element, its surface and the surface of the previously fixed lingual element partially overlap each other from the side of the approximate surfaces with the formation of longitudinal stiffeners.

Thus, the reinforcing mesh-composite pin formed during the restoration of the completely absent crown part of the lower incisor consists of pre-formed in accordance with the shape of the reinforced surfaces of the lingual and vestibular elements made of dental gilded metal mesh, sequentially fixed in the root canal with the formation of longitudinal stiffeners from the side of the approximate surfaces of the crown. After fixing the reinforcing mesh-composite pin, the final restoration of the reinforced crown part of the lower incisor is carried out using composite material. Before polishing and control polymerization, occlusal editing is carried out.

The central lower incisor restored by the claimed method is a monolithic structure formed by the root canal reinforced by 1/2 length and surface-reinforced by the crown part, additionally reinforced with stiffeners from the proximal surfaces. Due to the reinforcing of the root canal and the coronal part of the incisor, structural strength is achieved, and the load distribution is uniform during chewing.

Reinforcing the surface of the crown of the tooth provides a uniform fit of the boundary layers of the composite material, eliminating the formation of chips and chips on the side and cutting surfaces of the crown of the tooth.

The reinforcing vestibular mesh element provides reinforcement 1/2 of the length of the vestibular wall of the root canal and the vestibular and approximate surfaces of the crown of the tooth.

The reinforcing lingual mesh element provides reinforcing 1/3 of the lingual surface of the root canal, and in the coronal part - the tubercle. The reinforcing mesh-composite pin provides double reinforcement of the proximal surface.

Given the fact that the lower incisors during bending work on bending, additional reinforcement of the lingual surface of the root canal and tubercle ensures the reliability of the structure and prevents fracture of the crown of the tooth in the cervical part of the lower incisor.

Reinforcing vestibular mesh element, reinforcing lingual mesh element with composite material substitute a single monoblock, ensuring the duration of the structure.

The aesthetic effect is achieved after preliminary processing and grinding with standard polishing discs of various thicknesses and grit sizes, diamond burs, and processing of approximate surfaces with strips. Occlusive editing is carried out under the control of occlusal paper with finishing burs, discs.

Thus, the implementation of the claimed method allows for restoration in the complete absence of the crown part of the central lower incisor, restoring its anatomical shape and function.

Claims (1)

The method of restoration of the central incisors of the lower jaw in the complete absence of the crown part using a reinforcing mesh-composite pin, including preliminary endodontic treatment of the root, expansion of the root canal taking into account its direction and taper, and subsequent reinforcement of the inner surface of the root canal and the crown part of the incisor by means of a pin consisting from sequentially fixed in the root canal of the lingual and vestibular reinforcing elements previously formed from gilded metallic mesh in accordance with the shape and size of the reinforced surfaces, the length of the root of which is chosen equal to 1/3 of the root canal of the lingual element and 1/2 of the root canal of the vestibular element, and the height of the root part of the lingual element is equal to the height of the lingual surface of the coronal parts at the level of the tubercle, and the lingual and vestibular elements are fixed in the root canal with the possibility of their partial overlap with the formation of longitudinal stiffeners from the side of the approximate coronal surfaces parts, after reinforcing, the crown part of the incisor is restored with composite materials in accordance with its anatomical shape.