RU2845305C1 - Method for fixation of partial removable dentures - Google Patents

Abstract

FIELD: medical science.

SUBSTANCE: invention refers to medicine, namely to orthopaedic dentistry, and can be used in prosthetics of the patients with Kennedy class 2 and 3 dentition defects by making the dental arches. Patient is examined, surgical sanation, therapeutic preparation of the oral cavity is carried out, the consistency of the retainer teeth is assessed, a prosthetic plan is drawn up, the retainer teeth are prepared with the manufacture of temporary structures, imprints are prepared; a constructive occlusion is determined for making abutment crowns with attachments and milling for anterior and lateral teeth in the laboratory using a known method. For bearing molars or solitary premolars, crowns are made with an oral milled surface, a vertical slot in the transition from the oral to the distal surface parallel to the prosthesis introduction path and an undercut for the vestibular clasp. Milling is partially transferred to the chewing surface. In the removable prosthesis in the projection of the molars and single premolars described above, a milled shoulder is made with a vertical pin, and for the vestibular surface of the bearing molar or premolar in the removable part, a cast clasp is made, the structure as a whole is made and applied.

EFFECT: method enables achieving the optimum fixation of the removable denture in the distal portions, preventing the overload of the bearing molars, provides the transfer of the masticatory pressure along the tooth axis, and prevents the fracture of the structural elements.

1 cl, 10 dwg, 1 ex

Description

The invention relates to medicine, namely to orthopedic dentistry, and can be used in prosthetics for patients with class 2 and 3 dental defects according to Kennedy by manufacturing arch prostheses.

When manufacturing partial removable dentures for patients with partial tooth loss, the issue of achieving optimal fixation remains relevant as a prerequisite for long-term comfortable use of the structure.

Fixation is a general concept that includes retention, stabilization and support of the prosthesis (Trezubov V.N., Shcherbakov A.S., Mishnev L.M. Orthopedic dentistry. Propaedeutics and basics of a private course. - St. Petersburg: SpetsLit, 2001, - 480 p.).

A method for achieving fixation of partial removable dentures, including arch dentures, by creating a clasp system is known. A clasp arch denture made of cobalt-chromium alloy with cast support-retaining clasps is therapeutically justified and financially advantageous (Wulfes H. Modern technologies of prosthetics. - Bremen: Academy of dental, 2004. - 281 p.). Support elements can be made both for natural teeth and for crowns according to the shape of the teeth.

The disadvantages of this method are:

- dependence of the location and shape of the supporting and retaining elements of the prosthesis on the anatomy and position of the supporting teeth;

- the effect of the clasp on the hard tissues of the teeth;

- difficulty in achieving fixation with insufficient undercut depth;

- the impact of lateral load on the supporting tooth when applying and removing the prosthesis;

- the possibility of breakage of the clasp elements due to high mechanical load.

A method for manufacturing combined dentures for patients with partial tooth loss is known. In this case, the load distribution arms are manufactured using the milling method. They perform the functions of support and stabilization, and ensure vertical transfer of the chewing load to the supporting teeth. Particular attention should be paid to the formation of the vertical groove. The retention function is performed by a factory attachment. This design redistributes the chewing load between the supporting teeth and the alveolar part of the jaw in the most physiological way. However, in the case of single supporting molars or premolars, especially with 1 degree of mobility:

- if there are attachments in the canine or premolar area, the use of a third or fourth attachment in the molar area in one design will complicate the production of the product, its application, adaptation and operation;

- the use of a milled shoulder in the molar area, even with a vertical groove without an attachment, will lead to lateral loading on the supporting tooth, development of a vertical groove and slippage;

- the use of an attachment in the area of a single premolar will lead to overloading of the tooth.

A method of fixing arch prostheses using telescopic crowns is known (Lebedenko I.Yu., Peregudov A.B., Glebova T.E., Lebedenko A.I. Telescopic and locking fastenings of dentures, - 2nd ed., corrected and supplemented. - M.: Molodaya Gvardiya, 2011. - 350 p.). Despite the obvious advantages, the disadvantages of this method include:

- complexity of production,

- difficulty in regulating retention,

- the need for significant reduction of hard dental tissues.

A method of fixing an arch prosthesis in the molar area is known in the form of a ring-shaped milled shoulder without using the chewing surface (Wulfes H. Modern technologies of prosthetics. - Bremen: Academy of dental, 2004. - 281 p.). The advantages of this method include stabilization of the prosthesis and creation of support strictly along the axis of the tooth. The disadvantages include the lack of retention.

Zhulyov E.N. points out the advisability of creating a milled plane on the oral surface parallel to the path of insertion of the prosthesis (Zhulyov E.N. Partial removable dentures (theory, clinic and laboratory equipment): Manual for doctors. - 2nd ed., corrected. - M .: OOO "Medical information agency", 2011. - 424 p.). The present invention is fundamentally different in the presence of a vertical milled groove and a partial transition of milling to the chewing surface. This approach ensures the most physiological transfer of the chewing load along the tooth axis and the absence of the possibility of lateral displacement of the milled shoulder. Also, lateral impact on the clasp is excluded, which minimizes the likelihood of its breakage.

The objective of the proposed invention is to ensure the fixation of arch prostheses in the area of lateral teeth.

The set task is achieved by the fact that in the method of fixing partial removable dentures in orthopedic treatment of patients with defects of the dentition of class 2 and 3 according to Kennedy, including the manufacture of an arch combined denture, for which an examination of the patient, surgical sanitation and therapeutic preparation of the oral cavity are carried out, the viability of the supporting teeth is assessed, a prosthetic plan is drawn up, the supporting teeth are prepared in accordance with the prosthetic plan, temporary structures are made, impressions are obtained, the constructive bite is determined using a facial bow, the obtained working models are plastered in an adjustable articulator, in the laboratory in a known way, supporting crowns with attachments and milling for the anterior and lateral group of teeth are made, to create optimal fixation of a removable arch denture for molars and single premolars, crowns are made with an oral milled surface, a vertical groove in the transition from the oral to the distal surface and with a partial transition of milling to the chewing surface, wherein the plane milling is parallel to the path of insertion of the prosthesis, an undercut for the clasp is formed on the vestibular surface of the crown, a milled shoulder with a vertical pin is made for the oral surface of the crown of the supporting molar or premolar in a removable arch prosthesis, and a cast clasp is made for the vestibular surface of the supporting molar or premolar in the removable part, the structure as a whole is manufactured and applied.

The method includes the production of crowns for supporting molars or single premolars with an orally milled surface and a vertical groove in the transition from the oral to the distal surface and with a partial transition of milling to the chewing surface. The plane of milling is parallel to the path of insertion of the prosthesis. An undercut for a clasp is made on the vestibular surface of the crown. The milled shoulder with a vertical pin of a removable denture allows for reliable and physiological transfer of a significant chewing load to the supporting tooth parallel to the long axis of the tooth and eliminates the breakage of structural elements, provides stabilization and support. A cast clasp is made for the vestibular surface of the supporting molar or premolar in the removable part, which eliminates lateral shift of the milled shoulder, participates in ensuring stabilization of the structure, provides adjustable retention in the area of the supporting tooth.

The proposed method is implemented as follows.

1. The patient is examined to establish a diagnosis and draw up a treatment and prosthetics plan (questioning, examination of the face and oral cavity, additional examination methods - CT of the jaws, CT of the TMJ, clinical photography, obtaining control and diagnostic models of the jaws with plaster casting in the articulator).

2. Conduct surgical sanitation and therapeutic preparation of the oral cavity, provide training in the rules of personal hygiene and care of the prosthetic structure.

3. Prepare the supporting teeth in accordance with the prosthetic plan. Make temporary structures. Take impressions, determine the constructive bite. Using a face bow, plaster the obtained working models into an adjustable articulator.

4. In the laboratory, using a known method, supporting crowns with attachments and milling are made for the front and side groups of teeth.

5. For supporting molars or single-layered premolars, crowns are made with a surface milled parallel to the path of insertion of the prosthesis, a vertical groove and an undercut for the clasp. In the removable part, a milled shoulder with a partial transition to the chewing surface, a vertical pin and a cast clasp are made.

6. The removable part and the structure as a whole are manufactured and applied.

Clinical example 1

Patient K. came to the clinic with complaints of partial absence of teeth, difficulty chewing food, and an aesthetic defect.

Based on the results of the clinical examination, analysis of CBCT of the jaws, CT of the TMJ, and analysis of control and diagnostic models, the following diagnosis was made: partial loss of teeth, defect of the upper jaw dentition class 3 according to Kennedy, defect of the lower jaw dentition class 2 according to Kennedy, decreased interalveolar height.

The patient was offered and fitted with combined removable dentures with attachment fixation in the area of teeth 14 and 25 on the upper jaw and in the area of teeth 34 and 45 on the lower jaw. In order to ensure adequate fixation of the dentures, crowns with a milled surface, a vertical groove in the transition from the oral to the distal surface and an undercut for the clasp vestibular were made for teeth 17, 27 and 47. The milling partially extends to the chewing surface. In the removable dentures, milled shoulders, vertical pins and cast clasps were made in the projections of teeth 17, 27 and 47.

The example is illustrated by figures depicting:

Fig. 1.1 - combined arch prosthesis of the lower jaw with a fixation element, including for tooth 4.7.

Fig. 1.2 - an element for fixing an arch prosthesis on tooth 4.7 in the form of a milled shoulder parallel to the path of insertion of the prosthesis with a vertical pin in the transition from the oral to the distal surface of the crown and a cast clasp. The milling partially extends to the chewing surface.

Fig. 1.3 - metal-ceramic crown for tooth 4.7 with a milled surface parallel to the path of insertion of the prosthesis with a vertical groove in the transition from the oral to the distal surface. The crown has a vestibular undercut for the clasp.

Fig. 1.4 - combined arch prosthesis with fixation, including on metal-ceramic crowns on teeth 1.7 and 2.7.

Fig. 1.5 - combined arch prosthesis of the upper jaw.

Fig. 1.6 - an element for fixing an arch prosthesis on tooth 1.7 in the form of a milled shoulder parallel to the path of insertion of the prosthesis with a vertical pin in the transition from the oral to the distal surface of the crown and a cast clasp. The milling partially extends to the chewing surface.

Clinical example 2

Patient H. came to the clinic with complaints of partial absence of teeth, difficulty chewing food, aesthetic defect, and speech impairment.

Based on the results of clinical and paraclinical examination, analysis of CBCT of the jaws, analysis of control and diagnostic models plastered in the articulator, the following diagnosis was made: partial loss of teeth, defect of the upper jaw dentition class 3 according to Kennedy, defect of the lower jaw dentition class 1 according to Kennedy, decreased interalveolar height.

The patient received combined removable dentures with attachment fixation. In order to ensure adequate fixation of the upper jaw denture, a metal-ceramic crown with a milled surface, a vertical groove in the transition from the oral to the distal surface and an undercut for the clasp vestibularly was made for tooth 27. The milling partially extends to the chewing surface. In the removable denture, a milled shoulder, a vertical pin and a cast clasp were made in the projection of tooth 27.

The example is illustrated by figures depicting:

Fig. 2.1 - combined arch prosthesis with fixation, including, on a metal-ceramic crown on tooth 2.7.

Fig. 2.2 - combined arch prosthesis with fixation, including, on a metal-ceramic crown on tooth 2.7.

Fig. 2.3 - element for fixing the arch prosthesis on tooth 2.7, where:

1 - milled shoulder parallel to the path of insertion of the prosthesis with partial transition to the chewing surface

2 - vertical pin in the transition from the oral to the distal surface of the crown

3 - cast clasp for the vestibular surface of the crown.

Fig. 2.4 - metal-ceramic crown for tooth 2.7 with a milled surface parallel to the path of insertion of the prosthesis with a vertical groove in the transition from the oral to the distal surface. The crown has a vestibular undercut for the clasp.

Thus, in both clinical cases, the proposed method of fixing removable structures, which involves the manufacture of crowns for supporting molars or single premolars with an oral milled surface parallel to the path of insertion of the prosthesis, a vertical groove in the transition from the oral to the distal surface and an undercut for the clasp vestibularly (the milling partially goes onto the chewing surface), and in the removable prosthesis in the projection of the molars and single premolars indicated above, the manufacture of a milled shoulder, a vertical pin in the transition from the oral to the distal surface and a cast clasp, ensured adequate retention, stabilization and support.

The proposed method allows achieving optimal fixation of a removable denture in the distal sections, prevents overloading of supporting molars, ensures the transmission of chewing pressure along the axis of the tooth, and eliminates the breakage of structural elements.

Claims (1)

A method for fixing partial removable dentures in orthopedic treatment of patients with Kennedy class 2 and 3 dental defects, including the manufacture of an arch combined denture, for which purpose the patient is examined, surgical sanitation and therapeutic preparation of the oral cavity is performed, the viability of the supporting teeth is assessed, a prosthetic plan is drawn up, the supporting teeth are prepared in accordance with the prosthetic plan, temporary structures are manufactured, impressions are obtained, the structural bite is determined using a facial bow, the obtained working models are plastered in an adjustable articulator, supporting 4 crowns with attachments and milling for the anterior and lateral group of teeth are manufactured, characterized in that in order to create optimal fixation of a removable arch denture for molars and single premolars, crowns are manufactured with an oral milled surface, a vertical groove in the transition from the oral to the distal surface and with a partial transition of milling to the chewing surface, wherein the plane of milling is parallel to the path insertion of the prosthesis, an undercut for the clasp is formed on the vestibular surface of the crown, a milled shoulder with a vertical pin is made for the oral surface of the crown of the supporting molar or premolar in the removable arch prosthesis, and a cast clasp is made for the vestibular surface of the supporting molar or premolar in the removable part, the structure as a whole is manufactured and applied.