RU2341228C2 - Method of manufacturing of monobloc skeletons of stretched bridge-like prostheses with several basic crowns - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: cast not non-disposable model entirely including its socle part on a working print from a supergypsum, preliminary having carried out the print preparation, consisting that a peridental zone in a print round prints of all basic teeth - a zone round a print of a dissected basic tooth, circulary fill in with wax or silicon mass for an artificial gum, after casting of not non-disposable model spend casting of non-disposable model, applying a technique of manufacturing of the combined model. Model the wax preparation of the future monoblock skeleton of a bridge-like prosthesis on non-disposable model. After the end of modelling of the skeleton, separate it on fragments depending on a clinical situation, also transfer them with non-disposable on not non-disposable model. On not non-disposable model spend bond of fragments among themselves by means of wax or plastic for interdental intersections after that on the received wax composition establish the funel-creating pegs forming a funnel system. Take out the ready funnel system together with a wax composition of the skeleton of a bridge-like prosthesis from model and place in a ditch for casting from an alloy necessary for the future bridge-like prosthesis, fill the ditch with fire-resistant packing mass, melt the wax composition in a muffle furnace and spend casting of the skeleton from the fused alloy to the obtained form. After skeleton casting first spend try-in of every basic element of the skeleton - crowns to the corresponding stamp - the tooth from non-disposable model, then carry out try-in of the whole skeleton on the non-disposable model.

EFFECT: rising of accuracy of manufacturing of the monoblock skeleton of fixed tooth prostheses that excludes development of undesirable complications.

2 cl

Description

The invention relates to medicine, namely to prosthetic dentistry.

Recently, in dental practice, solid casts are increasingly being used to repair defects in teeth and dentitions. Technologies and materials used in orthopedic dentistry are constantly being improved. However, the frequency of complications in orthopedic treatment of patients using fixed dentures is still high. Unsuccessful outcomes of prosthetics with such structures in the first 2-3 years of use make up to 20%. The greatest number of prostheses removed is up to 5-6 years. The main reasons leading to the need for premature removal of fixed dentures are defects of the prosthesis itself (fractures, chipping of the lining and deterioration of the aesthetic properties, abrasion of the prosthesis), complications from the abutment teeth (caries, often the cervical region, pulpitis, etc.), pathology of periodontal tissues (gingival inflammation as a result of poor-quality marginal fit of crowns, presence of carious lesions of hard tissues of teeth, toxico-allergic effect of prosthetic materials on the gingival margin, occurrence of parods ontal pockets and tooth mobility), impaired fixation of the prosthesis.

In connection with the foregoing, it is urgent to develop a method for manufacturing solid cast frames of extended bridges, which eliminates the possible complications arising from this type of prosthetics.

A method of manufacturing a molded metal frame of a denture is known from the literature, including forming a model of the frame, obtaining a flask with its subsequent calcination, high-frequency melting of the metal alloy and cooling, moreover, the flask is calcined at 1000-1100 ° C for 30-40 minutes, high-frequency melting is carried out from an alloy of titanium nickelide at 1200-1250 ° C for 20-25 s (RU 2111722, publ. 1998.05.27).

There is also known a method of manufacturing a fixed bridge prosthesis, including the manufacture of a gypsum model, applying a preliminary layer of copper or zinc to the surface of the gypsum model by plasma spraying, forming a plasma-sprayed metal frame of the denture with a connecting beam in the gap between the abutment teeth, removing the preliminary layer by etching, applying a surface retention layer and facing a metal frame, characterized in that the gypsum model is made A collapsible beam including a model of the connecting beam is poured, a preliminary layer of copper (zinc) is applied to separate parts of the gypsum model, then a layer of metal 30-70 μm thick is sprayed onto the approximate surfaces of the models of the crowns of the supporting teeth, a model is assembled and a metal denture framework is formed by plasma spraying containing a connecting beam, 150-170 μm thick, after which the frame is heat treated and a surface plasma-sprayed retention layer of metal 30-50 μm thick is applied (RU 2177276, publ. 2001.12.27).

The closest analogue of the proposed method is the traditional method of manufacturing frames of bridges, which consists in the manufacture of a plaster model, on the basis of which the frame of the prosthesis is formed (Orthopedic dentistry. Textbook. Edited by V.N. Kopeikin, M., 2001).

However, the known analogues have a major drawback, namely, the working model is collapsible, which can lead to the emergence of micromotion of the dies of the collapsible model relative to each other, and, therefore, the proper manufacturing accuracy of the frame is not ensured.

The technical result achieved (through the use of the claimed sequence of actions) when implementing the proposed method is to increase the accuracy of the manufacture of the frame, which eliminates the likelihood of inaccurate fit and balancing of the frame, and therefore, to achieve optimal fixation of the prosthesis, to minimize the likelihood of developing periodontal tissue pathology and supporting teeth. This technical result is achieved due to:

- the use of a primary non-separable model, which is both an accurate working one for modeling and a control one for subsequent fitting and / or soldering,

- the primary non-separable model eliminates the possibility of the mobility of the dies relative to each other, which allows you to create optimal conditions for the exact manufacture of the frame (since the model itself is solid)

- reception of preliminary (before casting) filling in the imprint of the tooth with a silicone mass for artificial gums (gingival mask) or with regular base wax makes it possible to ensure that all the preparation margins of the supporting teeth are accessible and free from the surrounding gypsum gum, and therefore, optimal conditions for visualization, achievement and control of the exact fit of the prosthesis, which reduces the risk of development of pathology of tissues of supporting teeth.

The manufacture of a solid frame is as follows:

A working impression is obtained using conventional high-precision impression materials (polyester, polyvinylsiloxane, hydrocolloid, etc.). According to the working print, the non-separable model is first cast entirely from super gypsum, for example, 4 classes (including the basement), after preliminary preparation of the print. The preparation of the print consists in the fact that the periglossal (cervical) zone in the print around the imprints of all abutment teeth (the area around the imprint of the prepared abutment tooth) is circularly poured (isolated from ingestion, infiltration of gypsum) with base wax or special silicone mass for artificial gums (“gingival mask” "). This is done so that the entire neck and preparation margins of the abutment teeth are accessible both for visualization and for performing the necessary manipulations in this area, in other words, be free of the surrounding "gypsum" gum.

After casting the first (solid, non-separable) model, the second - collapsible model is casted using one of the well-known techniques for manufacturing a combined model. The working model is prepared traditionally - the cervical zone is treated, removing gypsum around the preparation margins, a reinforcing varnish, an insulating varnish and 2 layers of “spacer” are applied to the stamps on the entire surface of the gypsum stamp (treated tooth), not reaching a 1 mm ledge.

On a collapsible model, they begin modeling the wax billet of the future solid cast framework of the bridge according to the generally accepted methodology (immerse the die in immersion wax, pour cervical wax on the preparation margin, model the missing intermediate links).

After modeling the frame, it is divided into fragments (depending on the clinical situation) and transferred from a collapsible secondary to a collapsible primary model. In the primary model, fragments are interconnected using a special wax or plastic for interdental lintels (to avoid shrinkage). Then, on the resulting wax composition, gating pins forming the gating system are installed. The finished gate system together with the wax composition of the bridge frame is removed from the model and placed in the casting cuvette from the alloy necessary for the future bridge, the cuvette is filled with a refractory forging mass, the wax composition is melted in a muffle furnace and the frame is cast from the molten alloy into the mold obtained.

After casting the frame, first carry out fitting of each supporting element (crown) of the frame to the corresponding die (tooth) from the collapsible model. After fitting all the supporting crowns, they begin to fit the entire frame as a whole on the primary (most accurate) non-separable model. If it is found that during the removal from the model or during forging and casting linear changes or deformation of the frame occurred, the frame is cut in the place where it happened (previously analytically determining it), and the fragments obtained are soldered using special methods and intended for For this purpose, solders, conducting a preliminary connection of fragments using laser welding on a primary non-separable model.

Thus, the proposed method allows to increase the accuracy of manufacturing a solid cast frame of fixed dentures, thereby eliminating the development of undesirable complications.

Claims (2)

1. A method of manufacturing solid cast frames of extended bridges with several abutment crowns, characterized in that a non-separable model is cast using a working impression from super gypsum, including its base part, having previously prepared the impression, in which the dentition is in the impression around the prints of all abutments - the area around the imprint of the prepared abutment is circularly poured with wax or silicone mass for artificial gums, after casting a non-separable model of the casting of a collapsible model is carried out using the combined model manufacturing method, on a collapsible model, the wax blank of the future solid cast frame of the bridge is simulated, after the modeling of the frame is disassembled into fragments depending on the clinical situation, and they are transferred from the collapsible to the non-collapsible model, they are carried out on the collapsible model the fragments are interconnected using wax or plastic for interdental lintels, after which the casts are installed on the obtained wax composition the co-forming pins forming the sprue system, the finished sprue system together with the wax composition of the bridge frame are removed from the model and placed in the casting cuvette from the alloy necessary for the future bridge, the cuvette is filled with a refractory forging mass, the wax composition is melted into the furnace muffle and from the molten alloy into the obtained mold, after casting the carcass, first fit each supporting element of the carcass — the crown to the corresponding die — s boo from folding model, and then perform all of fit the frame as a whole to not folding model. 2. The method according to claim 1, characterized in that when detecting the balancing of the frame associated with the deformation of the wax composition of the frame when it is removed from the model before casting or irregularities in the process of modeling, forging and casting, the frame is cut at the place where it happened , and carry out the soldering of the obtained fragments using solders, conducting a preliminary connection of the fragments using laser welding on a non-separable model.