RU2132710C1 - Method of determining state of bearing teeth necks for prosthetics - Google Patents

Abstract

FIELD: medicine, in particular, stomatology. SUBSTANCE: method includes transillumination of subgingiva part of teeth necks by means of monochromatic coherent pulse laser light at wave length of 0.85-0.95 mcm and frequency of 2-3 kHz. EFFECT: accurate display of teeth. 1 cl, 3 ex

Description

 The invention relates to medicine, namely to dentistry.

 Determining the condition of the subgingival (invisible to the naked eye) part of the neck of the teeth is of significant interest for the diagnosis and subsequent treatment of various common dental diseases: caries of cement (especially on the proximal surfaces), periodontitis and periodontal disease, in the manufacture of crowns for supporting teeth and bridge prosthetics, etc. .

 Known methods for determining the condition of the crowns of abutment teeth for the manufacture of bridges using a movie or TV camera in the visible part of the optical spectrum (1-4).

 The disadvantage of the described methods is the inability to remove an important part of the abutment teeth, namely the subgingival part of the necks of the teeth, because the image is produced in the visible part of the spectrum, and the subgingival part in these images is not fixed because it is closed by the gum. At the same time, the reliability and longevity of a fixed metal dental prosthesis largely depends on the snug fit of the subgingival part of the metal crown to the tooth neck. Otherwise, the cement is resorbed, the crown will be disintegrated, caries of dentin and tooth cement occur, which can quickly collapse, the prosthesis loses its support and is removed.

 The determination of the condition of the subgingival part of the necks of the teeth can be obtained using x-rays, but this method requires special cumbersome and expensive methods, and also has a significant drawback - the harmful effect of x-rays, because sufficiently hard x-ray radiation is used for imaging dental tissues with a relatively long exposure.

 The purpose of the invention is to obtain an image of the subgingival part of the necks of the abutment teeth for prosthetics.

 This goal is achieved by the fact that to determine the state of the subgingival part of the abutment teeth, harmless (for the indicated purposes) monochromatic laser light in the IR range with a wavelength of 0.85-0.95 μm in a pulsed mode with a frequency within 2-3 kHz is used the mode of transmitted light through the studied tissue of the tooth.

 Analogs of methods are known that use achromatic geo-coherent light in the IR range (5), or laser light in the IR range, but in the reflected light mode, which makes it possible to determine the state of only the surface of the tissue under study (6). In both methods, light is used in the continuous generation mode. While the proposed method provides a pulsed generation mode, which allows more efficiently determining the state of tooth tissues with a sufficiently high resolution that meets the requirements for ensuring a snug fit of the edge of the metal crown to the tooth neck. A schematic diagram of the implementation of the proposed method consists in transmitting laser light with the above parameters through tooth tissue and outputting the image to a TV monitor.

 To obtain and transmit monochromatic coherent laser light through tooth tissues in the IR range with a wavelength of 0.85-0.95 μm with a frequency of 2-3 kHz, semiconductor laser emitters of the L-104 type produced by the domestic industry are used as a sensor. An optical system is located at the output of the laser emitter, which ensures the formation of a quasi-parallel beam of rays.

 As the receiver, a CCD camera is used, in front of which there is a focusing lens projecting the image of the object onto the photodetector matrix. A standard stabilized power supply is used to power the sensor.

 When the tooth tissue is visible in the neck region, its image is projected onto the focusing lens of the receiver, and the signal excited in the photodetector is sent to the output of the TV monitor, the optimal image configuration is selected, it is fixed (as a freeze frame) in the PC memory and transferred to the computer design block a denture in which the visible part of the tooth crown is automatically (according to a special algorithm) combined with the image of the subgingival part of the neck of the tooth. To accurately combine images of the supra- and subgingival parts of the tooth neck before they are removed, reference (reference) points are applied, which are applied in the form of a dye consisting of carcass and radiopaque substance in the region of the visible part of the tooth neck, at a distance of about 0.3-0.5 mm from the edge of the gums. Further stages of the design and manufacture of a fixed bridge (as well as individual crowns with fixation on stump deposits) are carried out by known methods (3, 4).

The above manipulations for removal in the infrared range are performed using a device consisting of two metal jaws in the form of stainless steel tubes with a diameter of 6 mm, at the distal ends of which, bent at an angle of 60 ^o with respect to their longitudinal axis, the sensor and receiver are mounted IR radiation. In the distal part, the jaws are connected by an elastic spring plate 0.8 mm thick and 0.8 mm wide and 18 mm wide. Conductors for powering the sensor and for diverting the signal from the receiver are located inside the tubular jaws and at the output have a connector for connecting to the cable of the power supply and input to the TV monitor.

 Examples of the proposed method.

обнаруженный при просвечивании лазерным светом с длиной волны 0.89 мкм. Лечение: с помощью ретрактора десневой край смещен вверх с обнажением дефекта цемента, размягченные участки цемента удалены экскаватором, затем сформированы бормашиной края дефекта с последующим наложением пломбированного йономерного материала. Контрольное просвечивание через 3 месяца показало плотное прилегание пломбировочного материала к тканям, глубина пародонтального кармана не превышает 1 мм.Example 1. Patient C., 49 years old. Diagnosis: caries of cement on the buccal surface of the neck

detected by transmission with laser light with a wavelength of 0.89 μm. Treatment: with the help of a retractor, the gingival margin is displaced upward to expose the cement defect, the softened areas of cement are removed by an excavator, then they are formed by a drill of the defect margin with subsequent application of the filled ionomer material. Control transillumination after 3 months showed a tight fit of the filling material to the tissues, the depth of the periodontal pocket does not exceed 1 mm.

Лечение: после препарирования

под искусственные коронки на вестибулярные поверхности

нанесены реперные точки и произведен съем поддесневых частей шеек

по предлагаемому способу. По описанному способу (3, 4) изготовлен несъемный металлический протез с керамическим покрытием.Example 2. Patient S., 26 years old. Diagnosis: absence

Treatment: after preparation

under artificial crowns on vestibular surfaces

reference points are applied and subgingival parts of the necks are removed

by the proposed method. According to the described method (3, 4), a fixed metal prosthesis with a ceramic coating was made.

плотно прилегают к области поддесневой части шеек 47. После проверки мостовидный протез зацементирован.Using the proposed method, it was found that the crowns on

fit snugly to the area of the subgingival portion of the necks 47. After checking, the bridge is cemented.

хронический пульпит.Example 3. Patient K., 32 years old. Diagnosis: carious destruction of the upper third of the crown

chronic pulpitis.

нанесена реперная точка. Приведен съем поддесневой части шейки при длине волны 0,85 мкм по предлагаемому способу.Treatment: under infiltration anesthesia, the softened parts of the crown were removed to a level of 2 mm above the gingival margin, pulp decay was removed, the root canal was formed under the stump tab and sealed with phosphate cement for 1/3 of the root length. The stump tab is made and cemented. On the vestibular surface of the neck

plotted reference point. The removal of the subgingival part of the neck at a wavelength of 0.85 microns by the proposed method.

 According to the described method (3,4), a metal crown with a ceramic coating is made. Using the proposed method determines the tight fit of the edges of the crown to the subgingival part of the neck of the tooth.

When testing the proposed method it was found that along with the main objective of the described method, a number of positive useful qualities of the method were revealed:
1) the proposed method can be used to detect caries of enamel on the proximal surfaces of tooth crowns and caries of cement in the subgingival part of the necks of the teeth and control of treatment results, including in the long term;
2) the proposed method can be used to detect subgingival tartar and control the quality of its removal;
3) using this method, you can control the quality of the manufactured crowns on the abutment teeth, namely, the degree of their fit to the necks of the teeth, which leads to high quality and long life (reliability) of manufactured prostheses;
4) using the proposed method, it is also possible to identify and track in dynamics the degree of atrophy of the bone tissue of the vertices of the alveoli, the width of the periodontal gap, as well as the presence of the initial stages of the formation of periodontal pockets;
5) during extirpation of the pulp of the abutment teeth, as well as after the treatment of apical periodontitis, the proposed method allows you to monitor the state of periapical tissues and identify their pathology, if necessary, determine the indications for treatment, for example, to resection of the apex of the tooth, etc.

Bibliographic sources
1. Production de protheses dentaires assistee par ordinatteur. Systeme Sopha-Cadcam. Sopha Bioconcept. 1991, p. 8.

 2. Construction assistee par ordinateur d'un inlay: Systeme CERE Siemens Aktiengesellschaft Division Technigue Medicale. Secteur Dentaire. 1993, p. eleven.

 3. Prokhonchukov A.A. The complex is automated for the manufacture of dentures. Dentistry -1991, N5, p. 7.

 4. Prokhonchukov A.A. The complex is automated for the manufacture of dentures. Inf. bull. "Computers and lasers in dentistry." M .: 1992, v. 1, p. fourteen.

 5. Carwright C. H. Infra-red transmission of fleisch. J. Opt. Soc. Am. 1930, v.20, p. 4-8.

 6. Benthon G., Minet O., Muller G., Paravat V. IR-Diaphanoskopy in Medicine. Laser Medizin Zentrum GMBH. Freie Universitat Berlin Kramester. SPIE, 1993, v. 18, p. 1.

Claims (1)

 A method for determining the state of the subgingival part of the neck of the teeth using laser radiation in the infrared range, followed by display on the TV monitor screen, characterized in that the transmission of the subgingival part of the neck of the teeth is carried out using monochromatic coherent pulsed laser light with a wavelength of 0.85 - 0 , 95 microns and a frequency of 2 - 3 kHz.