RU2234283C1 - Method for reinforcing composite materials in anchoring network mode in performing lacking frontal dental group crown part repair - Google Patents

Abstract

FIELD: medical engineering.

SUBSTANCE: method involves fixing anchor pin in root canal and in cavity formed in advance on root base, fixing metal network in pin head groove and in diametrically opposite grooves produced in root base in mesiodistal direction followed by building dental crown part with composite materials compliant to its anatomical shape. Two U-shaped protrusions are formed in pericervical tooth surface zone, distance between the protrusions matches anchor pin head width. Network grid is selected not to be greater than crown part height and width.

EFFECT: enhanced effectiveness in preventing sliding fractures and breaking off conditions; long service life.

Description

The invention relates to medicine, to aesthetic dentistry, to methods of mesh-anchor reinforcement of composite materials in the complete absence of the crown part in frontal groups of teeth.

It is known that the reasons for the complete absence of the crown part of the frontal groups of teeth are: caries, non-carious lesions, trauma: breaking off the crown of the tooth.

To restore the destroyed tooth crown while maintaining the root in dentistry, artificial crowns based on pin structures, direct and indirect restorations from composite materials, additionally reinforced with glass ionomer cements, chemical curing composites and various pin structures are used in dentistry (1-4, 6-7).

The prior art method for restoring the crown of the tooth, in which the head of the anchor pin (1) is used as the reinforcing element of the composite material.

The disadvantages of the known methods are:

1) low mechanical strength of the structure;

2) the contact area of the composite with the “head” of the anchor pin is only 20-30% of the total area of the crown part of the tooth being restored;

3) the head of the anchor pin is located at 1/3 of the height of the crown part of the tooth being restored (in the center), which ensures mechanical strength of the structure only in the cervical region;

4) 60-70% of the crown of the restored tooth remains without reinforcement, which leads to frequent chips and spallations of the composite.

In connection with the aforementioned restoration, in the complete absence of the crown part in the frontal groups of teeth with the use of anchor pins, they have not received wide clinical use.

The aim of this invention is the prevention of chips and spalls, increasing the durability of restoration / reconstruction of the crown of the tooth along with high aesthetics.

The advantage of the mesh-anchor method of reinforcing composite materials in the complete absence of the crown part in the frontal groups of teeth:

1) the metal mesh is not only a mechanical link between the anchor pin, composite, hard tooth tissues, but also the portions of the composite themselves;

2) a metal mesh and an anchor pin, connecting together mechanically, are presented as a single whole mechanical strong reinforcing structure, immured in a composite material;

3) the metal mesh not only increases the area of contact with the composite, but also provides 95% reinforcement of the crown of the restored tooth;

4) a metal mesh helps to reduce the shrinkage of the composite material and leads to an improvement in the marginal fit of the composite to the hard tissues of the tooth;

5) the metal mesh is connected with the base of the tooth root and with the head of the anchor pin, which allows you to evenly distribute the stress on the root under functional loads;

6) a metal mesh helps to reduce the stress (stress) that occurs during polymerization;

7) a metal mesh provides the prevention of possible complications of chips and spalls after restoration / reconstruction;

8) increases the durability of the restored tooth;

9) high aesthetics.

Grid-anchor method of reinforcing composite materials in the complete absence of the crown part in the frontal groups of teeth is as follows.

Preparing a tooth for restoration

Mechanically, the surface of teeth near the defect is cleaned with toothbrushes using toothpastes and a suitable color is determined according to the generally accepted VITA scale. After filling the apical third of the root canal of the restored tooth, the gum is retracted with retraction thread for greater access to the root of the tooth. After gum retraction with a thin conical diamond head, we process the root portion adjacent to the gum.

A semicircular cavity is formed on the basis of the root with the help of a spherical boron. An anchor pin is selected, which is removed after fitting. In the center of the root base, in the mesiodistal direction, with the help of a torpedo-shaped bur, two radial (diametral) grooves are mutually extending each other, one from the medial wall of the tooth root to the root canal, the other from the root canal to the lateral wall of the tooth root, departing from the lateral and the medial walls of the root of the tooth on average 1-2 mm in order to prevent perforation of the walls of the root of the tooth. The depth of the groove is formed taking into account the tapering of the tooth root, on average it is 1-2 mm.

Anchor pin fixing

Before fixing the anchor pin, the root base is etched; in this case, the root canal is closed with cotton wool in order to prevent the ingress of acid. Formed semicircular cavity and grooves are subjected to acid etching with acid -3 M SCOTCHBOND ETCHANT GEL (Dental materials. Catalog. 2001. ЗМ Dental, p. 6) to create a microrelief. Acid is applied with a brush, on average after 15-20 seconds, after which it is washed off with a stream of water when the saliva ejector is working. Next, the cotton wool is removed from the root canal and the anchor pin is fixed using S.I. (Glass ionomer cement. Dental materials. Catalog. 2001, 3M Dental, p.11) according to the standard method. Considering the fact that there is a cruciform groove on the head of the anchor pin, when fixing the pin, one of the grooves of the head must necessarily be in line with the formed groove on the root base.

The vestibular and palatine surfaces of the head of the anchor pin are ground 1-2 mm to ensure aesthetics.

Preparation of a metal mesh for reinforcing the root and crown parts of a tooth

As a reinforcing element, a metal mesh with small cells of stainless steel 0.4 mm thick by Renfert (USA) is used. The metal mesh is designed to strengthen plastic prostheses (Products for dental technicians: Catalog. 2001-2002, p. 102-103).

The metal mesh is selected so that the length and width of the mesh correspond to the length and width of the missing crown of the tooth.

The metal mesh is conditionally divided into three parts:

1) cutting surface;

2) the body;

3) cervical surface.

On the cervical surface of the mesh using scissors creates two protrusions of a U-shaped. The width of the protrusions should correspond to the width of the formed grooves on the base of the root, and the distance between the protrusions should correspond to the width of the head of the anchor pin.

Trying on a metal mesh

Two protrusion protrusions without tension should enter the formed grooves on the root base, while the intermediate part between the protrusions should enter the groove of the head of the anchor pin. On approximate surfaces, the width of the mesh should be already 1 mm, and the cutting surface should be shorter by at least 1-2 mm of the edge of the restored tooth to ensure transparency of the cutting edge after restoration.

After fitting, the metal mesh is washed under a stream of water, dried with air, then two layers of adhesive are applied, polymerized and then a masking agent - 3M ™ RelyX ™ CERAMIC PRIMER (Dental materials: Catalog. 2001, 3 M Dental, p. 3) is applied in this way to preserve the meshing.

The final restoration of the missing cortical part of the tooth using a metal mesh

Isolation from the liquid environment of the oral cavity using a rubber dam (5).

After fixing the pin, an adhesive is applied both to the semicircular cavity and groove (formed on the root base) and to the head of the anchor pin (Dental materials: Catalog. 2001, 3 M Dental, p. 6) 3M ™ SINGLE BOND DENTAL ADHESIVE SYSTEM using the applicator . Rubbing the adhesive, lightly blow with air; re-apply the adhesive and re-blow with air. Polymerized by a standard method for 10 s.

Using a macrophilic composite (Dental materials: Catalog. 2001, 3 M Dental, p. 4), a border of 1.5-2.0 mm high is formed at the level of the gums around the entire perimeter of the formed cavity.

The grooves are filled with 3M ™ Filtec ™ Flow fluid composite (Dental materials: Catalog. 2001, 3 M Dental, p. 3) and at the same time a metal mesh is placed in the groove so that the two cervical protrusions enter the groove formed in the cavity of the cervical part of the root ( without voltage), and the intermediate part between the protrusions entered the groove of the head of the anchor pin. Before polymerization, the head of the anchor pin (in the groove of which there is a metal mesh) is mechanically compressed with crown-shaped spokes, and then polymerization is carried out.

Thus, the metal mesh, which replaces the missing crown of the tooth, is connected to the root of the tooth in two ways:

- adhesive (using cervical protrusions);

- mechanical [the intermediate part of the grid (between the protrusions) is connected to the head of the anchor pin].

Next, the final restoration of the crown of the tooth is carried out with composite material for the front groups of teeth - 3M ™ FILTEK ™.

The first portion of the composite material is applied to a metal mesh and removed to improve the adhesive ability of the material. First, the tooth contour is restored using macrophile P-60 - 3M ™ SOF-LEX ™ (Dental materials: Catalog. 2001, 3 M Dental, p. 4). Then, in a layer-by-layer manner, we apply opaque and enamel layers of the composite onto a metal mesh, first onto the oral and vestibular surfaces (directional polymerization is carried out from the vestibular and oral sides), because light-curable composite material shrinks toward the directional light source (directional polymerization technique allows to reduce polymerization shrinkage, improve edge fit). To improve grinding and subsequent polishing with circular brushes and pumice, the dispersion layer of the composite (inhibited by oxygen) is removed. The aesthetic effect is achieved after pre-treatment and grinding with standard polishing discs - 3M ™ SOF-LEX ™ (Dental materials: Catalog. 2001, 3 M Dental, p. 8) of various thicknesses and grit sizes, diamond burs, and the approximate surfaces are treated with strips - 3M ™ SOF-LEX ™ (Dental Materials: Catalog. 2001, 3 M Dental, p. 8). Occlusive editing is carried out under the control of occlusal paper with finishing burs, discs. Finishing is performed from the palatine and vestibular surfaces, the rubber dam and retraction thread are removed. Final grinding and polishing is carried out on the second day after polymerization. Thus, this method allows to increase the structural strength, increase the durability of the restoration / reconstruction with the complete absence of the crown of the tooth along with high aesthetics.

Example

Patient M., 28 years old. Complaints: aesthetic dissatisfaction, complete destruction of the crown 12.

Anamnesis: According to the patient, the 12th tooth was previously repeatedly treated for complicated caries.

External examination without features, the mucous membrane of the oral cavity is not changed. Orthognathic bite.

Objectively: the crown of the 12 tooth is completely destroyed. Percussion is painless. There are no periapical changes on the X-ray of the 12 tooth, the canal is sealed to the apex.

Diagnosis: complete absence of crown 12.

Treatment: Mechanically, the surfaces of teeth near the defect are cleaned with toothbrushes using toothpastes and a suitable color is determined according to the generally accepted VITA scale. Gums are retracted with retraction thread for greater access to the root of the tooth. After gum retraction, a root cone adjacent to the gum is treated with a thin cone-shaped diamond head.

A semicircular cavity is formed on the basis of the root with the help of a spherical boron. Anchor pin is selected, which is removed after fitting. In the center of the root base in the mesiodistal direction, two radial (diametral) grooves are formed using a torpedo-boron, mutually extending each other: one from the medial wall of the tooth root to the root canal, the other from the root canal to the lateral wall of the tooth root, departing from the lateral and medial walls of the root of the tooth on average 1-2 mm in order to prevent perforation of the walls of the root of the tooth.

Before fixing the anchor pin, the root base is etched, while the root canal is closed with cotton wool (in order to prevent acid ingress). Formed semicircular cavity and grooves are subjected to acid etching to create a microrelief. The acid is applied with a brush, on average after 15-20 seconds, after which it is washed off with a stream of water with the saliva ejector working. Next, the cotton wool is removed from the root canal and the anchor pin is fixed using S.I. (glass ionomer cement) by a standard method. When fixing the anchor pin, the groove of the head is aligned with the formed groove on the base of the root. The vestibular and palatine surfaces of the anchor pin are ground 1-2 mm.

As a reinforcing element, a metal mesh with small cells made of stainless steel 0.4 mm thick by Renfert is used.

The metal mesh is selected so that the length and width of the mesh correspond to the length and width of the missing crown part of the tooth, that is, the mesh has a rectangular shape.

On the cervical surface of the mesh using scissors create two protrusions of a U-shaped. The width of the protrusions corresponds to the width of the formed grooves on the root base, and the distance between the protrusions corresponds to the width of the head of the anchor pin.

After fitting, the metal mesh is washed under a stream of water, dried by air; then an adhesive is applied, polymerized, and subsequently a masking agent is applied in such a way as to preserve the cellularity of the mesh.

Before the final restoration of the crown part of the tooth, isolation from the liquid medium of the oral cavity is carried out using a rubber dam.

After fixing the pin, adhesive is applied to the semicircular cavity and groove (formed on the root base) and to the head of the anchor pin using an applicator. Rubbing the adhesive, lightly blow with air, re-apply the adhesive and re-blow with air. Polymerized by a standard method for 10 s. The grooves are filled with a fluid composite and at the same time a metal mesh is placed in the groove so that the cervical two protrusions enter the groove of the root base (without voltage), and the intermediate part between the protrusions fits into the groove of the head of the anchor pin. Before polymerization, the head of the anchor pin (in the groove of which there is a metal mesh) is mechanically compressed, and then polymerized.

Next, the final restoration of the crown of the tooth is carried out with composite material for the front groups of teeth.

The first portion of the composite material is applied to the surface being restored (metal mesh) and removed to improve the adhesive ability of the material. First, the tooth contour is restored using a macrophile. Then, the opaque and enamel layers of the composite are applied in layers to the metal mesh, first to the oral and vestibular surfaces (directional polymerization is carried out from the vestibular and oral surfaces). To improve grinding and subsequent polishing with circular brushes and pumice, the dispersion layer of the composite (inhibited by oxygen) is removed. After pre-treatment and grinding with standard polishing discs of various thicknesses and grit sizes, diamond bores achieve an aesthetic effect, and proximal surfaces are treated with strips. Occlusive editing is carried out under the control of occlusal paper with finishing burs, discs. Light curing is done from the palatine and vestibular surfaces, the rubber dam and retraction thread are removed. Final grinding and polishing is carried out on the second day after polymerization. The treatment according to this method allows to increase the structural strength, increase the durability of the restoration.

Complications after restoration / reconstruction in the complete absence of the crown of the tooth by the above method were not identified.

Sources of information

1. Galimov I.Yu. Clinical experience with the use of anchor pins for restoration of the crown of the tooth / Dentist-practitioner, 2001, No. 1, pp. 28-30 - prototype.

2. George Friedman. Aesthetic treatment using the technique of restoration on a pin. / Clinical Dentistry, 2001, No. 2, pp. 10-15.

3. Kopeikin V.P. Guide to orthopedic dentistry. - M., 1998, p. 496.

4. Nikolaev A.I., Tsepov L.M. Practical therapeutic dentistry. St. Petersburg, 2001.

5. Nikolishchin A.K. Restoration (restoration) and tooth filling with modern materials and technologies. - Poltava: 2001, p. 72-77.

6. Svetlov A.V., Kozitsina S.I. Experience with root pins of the COSMOPOST./ Scientific and Practical Journal of the Institute of Dentistry, 2000, No. 1, pp. 28-30.

7. Olesova V.N. Biomechanical and clinical substantiation of fiberglass-based pin designs. / Panrama Orthopedic Dentistry, 2000, pp. 4-6.

8. Jordan R. E. Composite filling and facing materials in dentistry. A. V Borisenko, V.N. Not without reason. - Kiev: 2001, p. 200.

Claims (1)

A method of mesh-anchor reinforcement of composite materials during restoration of a completely absent crown part in anterior teeth groups, including fixing an anchor pin in a root canal and in a cavity previously formed on a root base, fixing a metal mesh in a groove of a head of a pin and diametrically opposite grooves made on a base root in the mesiodistal direction, and the subsequent formation of the crown part of the tooth with composite materials in accordance with its anatomical shape, and with Rhone cervical tooth surface in mesh form two U-shaped projection, the distance between which corresponds to the width of the head of the anchor pin, and the selected mesh size not more than the height and width of the crown part.