RU2268022C1 - Method for manufacturing cast pin stump insert - Google Patents

Abstract

FIELD: medical engineering.

SUBSTANCE: method involves manufacturing stump part on model produced from imprint. Subgingival part and pin structure part are modeled directly in the oral cavity.

EFFECT: avoided root tooth removal.

Description

The invention relates to medicine, namely to orthopedic dentistry, and can be used to restore a destroyed stump of a tooth below the level of the gums with the possibility of subsequent manufacture of a covering structure.

A known method of manufacturing a pin-stump tabs in a direct way. With the direct method of manufacturing the specified design, modeling of the structure is carried out directly in the oral cavity (Shcherbakov A.S., Gavrilov E.I., Zhulev E.N. Orthopedic dentistry: Textbook. - 4th edition, revised and supplemented. - St. Petersburg, 1994, p. 131).

The direct method has the following disadvantages: the use of wax for modeling is undesirable, since it can easily be deformed during manipulation, the duration and complexity of the manipulations for the doctor and patient.

The closest analogue is the indirect method, which consists in the following: after preparing the root canal and the stump of the crown, a plastic pin is fitted and the impression is taken. The model is cast according to the mold, and the design is made on the model. The specified method has the following disadvantage when the preparation margin is below the gingival level: the impossibility of obtaining a model with clear boundaries of hard tissues and gums (Kalamkarov Kh.A. Orthopedic treatment using ceramic-metal prostheses. MIA, Moscow, 2003, p. 39).

The invention is aimed at solving the following problems: improving the accuracy of the manufactured structure in the area located under the gum, and the ability to create a full-fledged stump for the covering structure.

Effect: preservation of the root of the tooth from removal.

These problems are solved by modeling the subgingival and pin parts of the structure directly in the oral cavity using quick-hardening ash-free plastic, and the rest of the stump is modeled on the model obtained from the cast.

The manufacturing method is as follows. After standard procedures for preparing the root canal (filling the apical third, expanding and calibrating the remaining part under an ashless pin, creating a cushioning cavity at the mouth, smoothing out acute angles and grinding the open root surface), a standard ashless pin is fitted in the canal and its length is adjusted according to the length of adjacent teeth , or in their absence up to 3-4 mm above the level of the remaining part of the root. On the protruding part of the pin, a thickening is created for fixing in the impression material, for example by reflow. An impression spoon is selected and the impression is taken with a base layer of silicone impression material. Next, the root canal, as well as the gum, facing the hard tissues, is treated with liquid paraffin with a brush, excess oil is blown up with air. In a glass crucible, a portion of quick-hardening ashless plastic is diluted to a liquid consistency, and an insulin syringe with a needle is filled with it. The needle is inserted into the lumen of the root canal and the contents of the syringe are extruded into the canal. The pin-billet treated with the plastic monomer is introduced into the root canal, while excess plastic is squeezed out. After curing the plastic, the pin is removed to check the quality of the processing of the channel walls and the absence of pores in the plastic. If necessary, correct errors. Next, the preform is again introduced into the root canal and new portions of plastic are added until the defect in the subgingival part is filled, making sure that there is no excessive displacement of the gums. If necessary, a ledge is formed on the plastic. Thus, the modeling of the subgingival and pin parts of the structure is carried out directly in the oral cavity. Further, in the base layer of the impression, in the area of the destroyed tooth, a space is cut out with a scalpel for placing the pin, interdental spaces and undercuts are cut off in the region of the alveolar ridge. The cast is filled with corrective material and injected into the oral cavity without significant pressure. Then get an impression from the opposite jaw and determine the central occlusion. The simulation of the reproduction of the pin-stump tab on the model is completed according to the usual method. Reproduction of the design is passed to the cast. After appropriate processing (fitting on the model, sandblasting and steam-blasting, polishing the surface facing the gum), the molded pin-stump tab is checked in the oral cavity, fixed in the root canal and a covering structure is made.

Examples of specific performance.

Example 1. Patient D., 30 years old, complained of a fracture of the crown of the 11th tooth as a result of an injury. After the examination, the diagnosis was made: a fracture of the crown of a depulated 11 tooth, a total defect of the crown of the 11 tooth, the fracture line passes through the neck of the tooth and the defect extends under the gum by about 5 mm from the vestibular surface. The root canal is obturated to the apical foramen; in the X-ray diffraction pattern, there is a slight deformation of the periodontal gap in the region of the apex of the root as an extension. After preparing the root canal for the pin structure according to the method described above, the pin and subgingival portions of the structure were modeled directly in the oral cavity with the creation of a circular ledge, casts were taken and central occlusion was determined. The model completed the modeling of the structure, and the reproduction was transferred to casting. The cast pin-stump tab after treatment was transferred to the clinic, where it is fixed in the tooth. In the following visits, a cast crown lined with ceramics is made. Aesthetic result suits the patient.

Example 2. Patient O., 45 years old, complained of a fracture of a tooth in the upper jaw while eating. The tooth was previously treated, repulped and restored using restoration material. After the examination, the diagnosis was established: a crown fracture of a depulped 23 tooth, a subtotal crown defect of a 23 tooth, a fracture line on the medial surface is 4 mm below the gum, hard tissues protrude by 1.5 - 2 mm on the distal surface. On the roentgenogram, the root canal is partially obstructed, the apical third without filling material, in the region of the root apex, deformation of the periodontal gap in the form of expansion.

The root canal is sealed, the apical third is sealed. After preparing the root canal for the pin structure according to the method described above, the pin and subgingival portions of the structure were modeled directly in the oral cavity with the creation of a circular ledge, casts were taken and central occlusion was determined. The model completed the modeling of the structure, and the reproduction was transferred to casting.

The positive effect of using this method of manufacturing the pin-stump tab is as follows: it is possible to directly simulate the subgingival part of the structure, i.e. accuracy improves in this area; the time of manipulations in the oral cavity is reduced, i.e. increases the comfort of treatment for the patient.

Claims (1)

A method of manufacturing a cast pin-stump tab by manufacturing the stump part of the structure on a model made by cast, characterized in that the modeling of the subgingival and pin parts of the structure is carried out directly in the oral cavity.