Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C9/00—Impression cups, i.e. impression trays; Impression methods
  • A61C9/002—Means or methods for correctly replacing a dental model, e.g. dowel pins; Dowel pin positioning means or methods

Definitions

• the present invention relates to a device for producing a dental work model for the preparation of prosthetic work.
• a method for producing tooth crowns and bridges is already known, in which a casting mold is used as a model base, which consists of three individual parts that can be joined together, namely an approximately pine-shaped base plate with an approximately matched tongue shape, from the straight back of the Base plate outgoing paragraph, as well as an outer wall adapted to the shape of the base plate with vertical grooves provided on its inside and a rear wall.
• the assembled form is poured out and the plaster-side correction impression, which is also poured out, is placed on this.
• the plaster model produced in this way can be removed from one another by loosening the individual mold parts and then sawn through between the individual tooth stumps.
• the invention is based on the object, starting from the prior art described above, to improve it in such a way that a rigid, absolutely safe and precise guidance of the plaster model, in particular in the sawn-off state, takes place in the model base and easy demolding of the plaster model is possible .
• a model base which is characterized in that it consists of a one-part base shape with a cavity adapted to the size of the jaw with ribs formed on its two equally high inner surfaces for the formation of retention marks.
• the cavity widens approximately from the bottom to the top in the shape of a truncated cone and the ribs are ramp-shaped and wedge-shaped in cross-section and continuously increase from the upper to the lower edge of the cavity. It is also an advantage if the Rip is rounded. It is provided according to the invention that the cavity is open at the top and bottom.
• This configuration according to the invention in particular the conical shape of the cavity, the ramp-shaped configuration of the ribs and the rounded rib edges, results in easy demolding of the hardened plaster model from the model base, and without any mechanical aids being required for this, but this demolding can be achieved by slight Apply pressure from below against the gypsum mass because the cavity is also open towards the bottom.
• the downwardly open design of the cavity has the advantage that it can be precisely checked whether the entire cavity is completely poured out during pouring and in particular whether the casting material has been evenly distributed into the interstices between the ribs, so that the later hardened plaster model with the one applied above Has positive impressions of the teeth or tooth stumps in its lower guide area located in the model base of retention grooves formed by the ribs of the model base.
• the presence of retention grooves on both sides of the plaster model ensures that the dies are guided absolutely securely in both ends of the model base, especially after sawing the plaster model.
• the individual parts are guided independently of one another so that they can be pulled out or inserted as desired without the need to fear a displacement of the adjacent individual parts in the model base.
• the number of ribs on both inner walls of the cavity is fundamentally arbitrary. However, it is particularly advantageous to provide as many ribs as possible, namely the same number on both walls, in order to maximize the number of retention own brands in the plaster model, so that a secure mounting of the sawn stumps in the plaster model is guaranteed in any case.
• webs according to the invention are formed in the lower part of the cavity between the two walls thereof.
• the model base expediently has a height of about 2 to 3 cm, i.e. If possible, 2 to 3 times the tooth height on which the impression of the plaster surface is placed on the plaster surface in the cast state. Because this results in a sufficiently long guide area of the finished positive impression body in the model base, which is particularly important after the body has been sawn into the individual parts. A relatively short guide area would lead to an insufficiently tight fit of the individual die and would make subsequent dental processing difficult. Incidentally, it must be pointed out that only the conical design of the cavity opening upwards according to the invention makes it possible to keep the cavity open towards the bottom, since this conical embodiment naturally limits the insertion path of the sawn-off individual parts, so that these cannot fall down.
• FIG. 1 is a top view of a base shape according to the invention
• Fig. 2 is a bottom view of an inventive
• FIG. 3 shows a detail of the base shape according to FIG. 1
• FIG. 4 shows a perspective view, partly in section, of the base shape according to the invention according to FIG. 1
• FIG. 5 shows a section along the section line VV in FIG. 1 while simultaneously 6 shows a side view of the back of the base shape according to the invention with a lid
• FIGS. 1 and 2 and 4 show a base mold 1 according to the invention, which serves as a prefabricated part as a model base of a working model or saw model for the creation of prosthetic work, consists of a molded body 2 which is adapted to the jaw sizes. This molded body is resistant to deformation and solid plastic part.
• a suitable plastic material is a plastic made of polycarbonate of 4,4-Dioxidphenyl-2,2-propane (polycarbonate), which is very temperature-resistant, acid-resistant and dimensionally stable. Another advantage of this plastic is that it is clear and crystal clear.
• This molded body 2 has approximately a semicircular outer wall 3, which has a central rounded and two opposite, laterally flattened parts and an inner, approximately parabolic wall 4 and a rear wall 5, which closes the molded body on the rear side. From these walls 3, 4, 5, a cavity 6 corresponding approximately to the shape of the dental jaw is formed, which widens from bottom to top, so that it has an approximately frustoconical profile in cross section. Narrow ribs 9 are formed on the cavity inner surfaces 7, 8.
• the largest possible number of ribs 9 is present, preferably about 15 to 30 ribs are distributed next to one another on the inner surface.
• the number of ribs 9 should preferably be the same size on the two inner surfaces 7, 8.
• the distances between the ribs 9 from one another become closer to the center of the inner surfaces.
• the profile of the ribs is approximately ramp-shaped and it begins at the upper edge of the cavity 6 and rises continuously towards the lower edge, the final height of the ramp being approximately 2 to 3 mm.
• the wall height of the molded body is approximately 2 to 3 cm.
• the cavity 6 is open at the bottom, but bottom webs 11 are formed in its lower region, which connect the two walls 3, 4 and serve as spacers and for stiffening.
• a horizontal plate 12 is formed, which is offset downwards relative to the upper edges of the walls 4, 5. This results in an upwardly open space 13 which is separated from the cavity 6 by a web 14.
• the plate 12 can also be flush with the upper edges of the walls 4, 5.
• the molded body 2 has a cover 15 closable from above, which is connected to the molded body 2 via a joint 16.
• the lid advantageously also consists of the same material as the molded body.
• this impression which is the negative
• the molded body of the base mold 1 is poured into its cavity 6 completely to the brim with the same mass or to save costs with a mass of lower quality, for which purpose the base mold 1 is placed on a flat surface.
• the design of the base mold 1, which is open from the underside and transparent on all sides, can be used to check whether the casting compound has been distributed evenly over the entire cavity and has also penetrated evenly into all interstices between the ribs.
• the impression is now placed with its plaster side on the base mold 1, specifically on its plaster side, as shown in FIG. 8.
• the casting compounds located in both parts can connect to one another.
• the impression material carrier 20 can be removed, and the resulting working model is completed.
• the working model on the one hand includes the prefabricated base form 1 and on the other hand the positive impression body 21 located in the base form 1, as shown in FIG. 9.
• This positive impression body 21 has the teeth, the course of the gums and the palate in its upper region and a guide in the lower region section which has retentions 22 which have formed during the casting process through the ribs 9 of the molded body 2.
• the positive impression body 21 can be removed from the base mold 1 easily and without difficulty, which is made possible essentially by the frustoconical cross-sectional profile of the cavity 6 and the ramp-shaped configuration of the ribs 9.
• the manufacturing material used for the base has the property that no connection is made between the casting compound and the base, so that an otherwise necessary insulation is eliminated. Due to the height of the molded body and the resulting height of the lower guide area of the positive impression body, the base is securely guided. For further processing, only the positive impression body can be divided into individual parts using any technique / sawing.
• an insert 17 can be inserted into the cavity 6 of the molded body 2 from above, as a result of which the cavity can be divided. Such a subdivision is useful if only partial impressions are to be made.
• the insert 17 is designed such that it can be inserted between the ribs 9, so that a firm and tight fit is produced.
• the palate also has to be molded in some cases.
• the molded body according to the invention has the space 13, which is normally separated from the cavity 6 by the web 14.
• the web is - if necessary - milled off, so that the cavity 6 and the space 13 are connected to one another and can be filled with one another with a casting compound, so that the impression is now made with the palate impression section can also be put on.
• the cavity below the plate 12 is suitable for attaching any articulators.
• the dentist By additionally attaching a lid to the molded body, there is protection against external influences and packaging ready for dispatch.
• the dentist is able to produce the working model directly in his practice in a simple and quick manner, with a high degree of accuracy being guaranteed.
• the costs associated with the production of dental bridges are also considerably reduced by using the base shape according to the invention, since the work involved is considerably reduced.
• the base shapes according to the invention can be used several times.
• inaccuracies are largely eliminated, since the use of the prefabricated rigid molded body ensures absolute dimensional accuracy of the sawn tooth stumps within the base shape due to the mutual retentions present.
• the base shape according to the invention makes it possible, in a sawing technique in which the individual dies are sawn in and displaced from below and above, laterally displaced relative to one another, and broken, by fixing a particular individual die to fix the entire sawn plaster body in the model base. This locking can take place by inserting a pin laterally through the correspondingly drilled outer wall of the model base into the respective drilled individual die or a corresponding segment.

Landscapes

• Health & Medical Sciences (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Dentistry (AREA)
• Epidemiology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Dental Prosthetics (AREA)
• Dental Tools And Instruments Or Auxiliary Dental Instruments (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=25948162

Family Applications (1)

Country Status (14)

Families Citing this family (68)

Family Cites Families (13)

• 1978
  • 1978-07-26 DE DE19782856963 patent/DE2856963C1/de not_active Expired
  • 1978-07-26 CH CH330679A patent/CH621698A5/de not_active IP Right Cessation
  • 1978-07-26 GB GB7910880A patent/GB2023429B/en not_active Expired
  • 1978-07-26 BR BR7808673A patent/BR7808673A/pt unknown
  • 1978-07-26 WO PCT/DE1978/000015 patent/WO1979000076A1/de unknown
  • 1978-07-26 DE DE7838930U patent/DE7838930U1/de not_active Expired
• 1979
  • 1979-02-27 EP EP78900068A patent/EP0006881A1/de not_active Withdrawn
  • 1979-03-06 DK DK093379A patent/DK150215C/da not_active IP Right Cessation
  • 1979-03-15 NL NLAANVRAGE7902075,A patent/NL185129C/xx not_active IP Right Cessation
  • 1979-03-26 SE SE7902696A patent/SE428643B/sv not_active IP Right Cessation
  • 1979-03-28 US US06/024,862 patent/US4283173A/en not_active Expired - Lifetime
  • 1979-04-06 CA CA325,047A patent/CA1123634A/en not_active Expired
  • 1979-04-23 BE BE0/194779A patent/BE875785A/xx not_active IP Right Cessation
  • 1979-05-02 FR FR7911039A patent/FR2433931A1/fr active Granted
  • 1979-05-09 AU AU46904/79A patent/AU535096B2/en not_active Ceased

Non-Patent Citations (1)

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