Permanent prosthetic tooth crown and method for the prosthetic replacement of a tooth

Abstract

The invention relates to a permanent crown (1) of an implant-supported prosthesis, said crown comprising a base (2) connectable to a support part comprised of an abutment connected to an implant, and an onlay (3) having an occlusal surface (4) and being fastenable to said base (2). To reduce the amount of material and time consumed in the prosthetic replacement of a tooth and to reduce injury related to the replacement procedure, the base (2) performs the function of a healing abutment and has a contact surface configured to allow the onlay (3) to be form fitted thereto, said contact surface having at least one projection (14) or at least one depression (5, 6, 7).

Description

[0001] PERMANENT DENTAL CROWN AND METHOD OF TOOTH PROSTHETICS

[0002] Field of technology to which the invention relates

[0003] The invention relates to orthopedic dentistry, in particular to permanent dental prostheses, as well as to methods of fixed dental prosthetics supported by implants.

[0004] State of the art

[0005] An important condition for successful dental prosthetics with support on an implant is the complete engraftment of the implant to the patient's jaw bone tissue, called implant osseointegration. To achieve this, after the implant is installed, it is necessary to exclude the impact of loads associated with occlusion, i.e. the closure of the crown of the dental prosthesis with the antagonist tooth, on the implant for the period of osseointegration. Therefore, a permanent crown with an occlusal surface to ensure chewing function can be installed only after the implant osseointegration period has expired.

[0006] From the publication US 4997373 A it is known to make an artificial tooth with an occlusal and a main part, and in order to optimize the manufacture of the artificial tooth, its occlusal part is made of a material that is more durable than synthetic resin. This publication does not provide for the possibility of using the main part of the artificial tooth during the period of osseointegration of the implant.

[0007] The problem with dental procedures performed after the implant is installed and before the permanent crown is installed is the additional cost of time and materials, as well as the need for patient anesthesia, which complicates and increases the cost of the prosthetic process.

[0008] Disclosure of the essence of the invention

[0009] The present invention is aimed at solving the above problem.

[0010] To solve the problem, a permanent crown of a dental prosthesis supported by an implant is proposed, comprising a base connected to a supporting part, which is an abutment connected to the implant, and an overlay having an occlusal surface and fixed to the base, wherein the base performs the function of a gum former and has a contact surface made with the possibility of attaching the overlay to it with a geometric closure and having at least one protrusion or at least one depression. A connection with a geometric closure is understood to mean a connection realized due to the shape of the mating parts (Assembly Production Technology / M. A. Tamarkin, I. V. Davydova, 3.3. Tishchenko - Rostov n / D: Phoenix, 2007, p. 160).

[0011] In accordance with the invention, the permanent crown of the dental prosthesis is made in the form of a composite orthopedic structure, the use of which allows the dentist during the period of osseointegration of the implant to do without interventions associated with the formation of the gum, installation and removal of the temporary crown, and at the same time reliably eliminates the load on the implant during this period.

[0012] The technical result achieved by implementing the invention is complex and consists of: (i) reducing the material and time costs associated with dental prosthetics; (ii) reducing the overall trauma of the prosthetics procedure; (iii) reducing surgical and orthopedic manipulations after fixing the permanent crown on the supporting part; (iv) ensuring the strength and reliability of the permanent crown after the expiration of the osseointegration period.

[0013] Reduction of material and time costs associated with dental prosthetics and the overall trauma of the prosthetics procedure is achieved by refusing to use a temporary crown and gum former. After the implant is installed, the gum is formed around the base of the permanent crown, which is immediately installed on the supporting part of the dental prosthesis and which, as a rule, does not need to be removed during the entire process of osseointegration.

[0014] The reduction of surgical and orthopedic manipulations after fixing the permanent crown, as well as the safety of wearing the permanent crown during the osseointegration period, is ensured by the fact that during this period the base of the permanent crown, installed on the supporting part of the dental prosthesis, performs the function of a gum former and an aesthetic function. The base does not perform a chewing function, since it is the onlay that has the occlusal surface. Since the onlay is fixed to the base only after the osseointegration period, during which the contact surface of the base can be covered with a temporary filling if necessary, the risk of exposure to excessive load on the implant during the osseointegration period is reduced to a minimum.

[0015] After the implant has taken root, it is only necessary to fix the overlay on the base, which does not require any labor-intensive additional work. In addition, the above-mentioned connection of the base and the overlay with geometric closure is prepared in advance. This connection ensures an unambiguous mutual position of the overlay and the base, and also prevents the displacement and rotation of the overlay relative to the base, which ensures the strength and reliability of the permanent crown, consisting of the base and the overlay fixed to it, after the osseointegration period has expired, and then the cement or bond used to fix the overlay on the base will work mainly to counteract the tearing of the overlay from the base.

[0016] Thus, the connection of the overlay and the base with a geometric lock preferably ensures the impossibility of shifting and rotating the overlay relative to the base in any direction except in the direction of removing the overlay from the base.

[0017] Fixing the overlay to the base means fixing the overlay and the base in a connected state from separation. Fixing the overlay to the base can be provided by molecular forces of cohesion or adhesion, in particular, it can be carried out by means of cement or bond.

[0018] The above-mentioned support part, connected to the base and representing a separate abutment, can be connected to the implant by means of a threaded connection. The technical solution proposed in the invention can be implemented regardless of the material or design features of the implant and / or abutment.

[0019] In the first embodiment of the invention, the overlay may be made as a separate part having a contact surface aligned with the contact surface of the base and secured to the base by means of cement. In this case, the geometric closure of the base and the overlay is achieved by their conjugation with the alignment of their contact surfaces, which is understood as the introduction of these surfaces into contact with each other and / or their location near each other with a gap corresponding to the thickness of the layer of cement that binds them.

[0020] The corresponding contact surfaces of the base and the pad can be flat or curved.

[0021] In this case, the contact surface of the pad may have at least one projection or at least one depression. Then the projection of the base enters the corresponding depression of the pad, and / or the projection of the pad enters the corresponding depression of the base.

[0022] In a technologically advantageous embodiment of the contact surfaces, at least one projection and at least one depression are made crosswise. Any other shapes that provide geometric closure in the connection of the base and the overlay can also be used, for example, a star-shaped projection and depression. Such shapes are most suitable for molar prostheses that have a massive body.

[0023] For premolar and anterior teeth prostheses, contact surfaces of other shapes can be used.

[0024] In a second embodiment of the invention, the overlay may be formed by a permanent filling formed on the contact surface of the base using a bond. Such an overlay is fixed to the base during the formation of the permanent filling. In this embodiment, the geometric closure between the base and the overlay and the occurrence of molecular adhesion forces between them (and the bond) are carried out simultaneously during the formation of the permanent filling, when the filling material takes the geometry of the contact surface of the base and hardens.

[0025] A through hole can be made in the permanent crown, passing through the base and the onlay, in particular in the centre, to provide access to the supporting part. This hole can be used, in particular, to screw the abutment fixed to the base to the implant or to unscrew the abutment from the implant. After fixing the onlay to the base, the hole is sealed.

[0026] The base and overlay can be made in such a shape that the overlay after its attachment to the base covers the base from above, or from above-front, or from above-front and sides. The first of the two options is more suitable for prosthetics of molars, the second - for prosthetics of premolars or front teeth.

[0027] Any materials applicable for this purpose, in particular metal, such as zirconium, ceramics, metal-plastic, plastic, can be used to produce the permanent crown proposed in the invention. The base and the onlay of the permanent crown can be made of the same material or of different materials. The use of the same material is more advantageous in terms of processability and compatibility with cement in the first embodiment of the invention. Zirconium can be considered as a preferred material from which at least the base of the permanent crown is made.

[0028] In the case of an all-ceramic crown, dual-curing composite cement can be used to attach the onlay to the base of the permanent crown, while in the case of an all-metal crown, glass ionomer cement (GIC), zinc phosphate cement, or zinc polycarboxylic cement can be used. For example, in the case of a zirconium crown, glass ionomer cement (GIC) can be used, sometimes a special dual-curing composite cement.

[0029] Any technology used for the production of the permanent crown design elements may be used, such as injection molding, machining methods, or additive methods (3D printing). Digital scanning and computer-aided design / manufacturing (CADM) may be used to produce the permanent crown. Any new working technologies that may appear in the future may also be used to produce the permanent crown.

[0030] The above-mentioned problem is also solved in the method of tooth prosthetics using an implant and the permanent crown described above. When implementing the method proposed in the invention, an implant is installed in the patient's jaw, after installing the implant and the supporting part, a base of the permanent crown is installed on the supporting part, the osseointegration period necessary for the engraftment of the implant is maintained, and after the osseointegration period has expired, an overlay of the permanent crown is fixed to the base. In the first embodiment of the invention, the overlay is fixed to the base by attaching an overlay to the base, previously made in the form of a separate part. In the second embodiment of the invention, the overlay is fixed to the base by forming a permanent filling from a filling material on the base.

[0031] When implementing the method, the same technical result is achieved as discussed above in relation to the permanent crown proposed in the invention.

[0032] For aesthetic and / or hygienic purposes, the contact surface of the base can be covered with a temporary filling, which is removed before installing the overlay.

[0033] Brief description of the drawings

[0034] Examples of implementing the invention are discussed below with reference to the drawings, which schematically show: Fig. 1 is a perspective view of a permanent crown used for prosthetic restoration of a molar and comprising a base and an onlay arranged one above the other and at a distance from one another, surrounded by adjacent teeth; Fig. 2 is a bottom view of the contact surface of the onlay shown in Fig. 1; Fig. 3 is a top view of the contact surface of the base shown in Fig. 1; Fig. 4 is a side view of the base and onlay shown in Fig. 1, arranged one above the other and at a distance from one another; Fig. 5 is a perspective view from behind of the base and onlay in one example of implementing a permanent crown used for prosthetic restoration of a front tooth, surrounded by adjacent teeth; Fig. 6 is a perspective view from the front of the base and onlay in another example of implementing a permanent crown used for prosthetic restoration of a front tooth, surrounded by adjacent teeth; Fig.7 - a rear view of another embodiment of an overlay for a permanent crown used for prosthetics of a front tooth; in Fig. 8 - a front view of the overlay shown in Fig. 7; in Fig. 9 - a top view of a base mating with the overlay shown in Fig. 7. Carrying out the invention.

[0035] In the drawings illustrating various embodiments of the invention, the same reference designations are used to designate the same or functionally equivalent elements of the permanent crown.

[0036] Fig. 1-4 illustrates an example of a composite structure of a permanent crown intended for molar prosthetics. The permanent crown 1 comprises a base 2 connected to the supporting part of the dental prosthesis, in particular to the abutment (not shown in the drawings), and an overlay 3 having an occlusal surface 4.

[0037] Base 2 has three depressions 5-7, made of different depths and located crosswise. Between the opposite sides of base 2 there is a deeper depression 5, to which depressions 6, 7 of smaller depth adjoin on both sides.

[0038] The overlay 3 has three crosswise arranged projections 8-10 corresponding to the depressions 5-7 made in the base 2. In particular, the projection 8, passing between the opposite sides of the overlay 3, has the greatest height and, when the overlay 3 is connected to the base 2, enters the depression 5. On both sides of the projection 8, projections 9, 10 of a smaller height adjoin, which, when the overlay 3 is connected to the base 2, enter the depressions 6, 7. The use of projections of different heights and corresponding depressions of different depths eliminates the possibility of installing the overlay 3 on the base 2 in the wrong orientation.

[0039] Overlay 3, after it is attached to base 2, covers base 2 from above.

[0040] As an alternative to the variant shown in Fig. 1-3 or in addition to it, at least one projection can be provided on the base 2, and at least one depression can be provided in the overlay 3. The design of the base 2 with depressions is, in principle, more advantageous for covering the relief of the upper surface of the base with a temporary seal than the design of the base 2 with projections.

[0041] Instead of the three projections and three recesses shown in Fig. 1-4, one cross-shaped recess may be provided, into which one cross-shaped projection enters. In addition, the number of projections and recesses may be equal to two or may exceed three.

[0042] The depressions 5-7 and projections 8-10 shown in Fig. 1-4 are formed predominantly by flat, mutually complementary contact surfaces, the combination of which ensures the connection of the base 2 and the overlay 3 with a geometric closure, preventing the shift and rotation of the overlay 3 relative to the base 2.

[0043] For access to the abutment, a hole 11 is made in the base 2 and the overlay 3, indicated in Fig. 4 by a broken line. For connecting the base 2 to the abutment, the hole 11 in the base 2 is made in the form of a conical socket 12, ensuring a tight fit of the base 2 on the abutment and its centering relative to the abutment.

[0044] A similar composite structure can be used for a permanent crown intended for premolar prosthetics.

[0045] Fig. 5-9 illustrate examples of a composite design of a permanent crown intended for prosthetics of an anterior tooth.

[0046] In all these examples, the contact surfaces of base 2 and overlay 3 have a complex curvilinear shape, and overlay 3, when put on base 2, covers the base from above, from above-front and from the sides.

[0047] In the first example, shown in Fig. 5, in order to strengthen the geometric closure in the connection of the base 2 and the overlay 3 of the permanent crown intended for prosthetics of the front tooth, two depressions located next to each other are made in the upper edge of the base 2, and two projections 13 are made on the lower edge of the overlay 3 facing it, which, when the overlay is installed on the base, enter the depressions, preventing the displacement of the overlay 3 relative to the base 2.

[0048] To access the abutment, a hole 11 is made in base 2.

[0049] In the second example of making a permanent crown intended for prosthetics of a front tooth, shown in Fig. 6-9, two projections 14 located next to each other are made on the upper edge of the base 2, and in the lower edge of the overlay 3 facing it, two depressions 15 are made, into which, when the overlay is installed on the base, the projections 14 enter, preventing the displacement of the overlay 3 relative to the base 2. In Fig. 6, the base 2 is shown from the front, and the overlay 3 is shown separately from the base 2 and turned relative to it so that its side with the depressions 15 made in it is visible.

[0050] The overlay 3 in Fig. 7 and 8 differs from the overlay 3 in Fig. 6 by the smooth upper edge of the occlusal surface. The base 2 shown in Fig. 9 can be used to install the overlay 3 shown in Fig. 7 and 8.

[0051] The above-mentioned materials can be used to produce the base 2 and the overlay 3 of the permanent crown 1 proposed in the invention. The above-mentioned cements can be used to fasten the base 2 and the overlay 3. The invention can be implemented using any suitable materials that may be created in the future.

[0052] In all examples of the invention, the use of the composite structure of the permanent crown 1 allows one to do without a temporary crown installed for the period of osseointegration. After installing the overlay 3 on the base 2 and fastening them with cement, the composite permanent crown reliably withstands loads due to their connection with geometric closure.

[0053] The implementation of the invention is discussed above for a composite structure of a permanent crown consisting of a base 2 and an overlay 3, connected in the form of prefabricated parts. At the same time, the given description and the drawings explaining it will also allow a specialist to easily implement the invention by forming an overlay 3 on the base 2 in the form of a permanent filling using known or promising filling materials and bonds.

Claims

CLAUSE OF THE INVENTION 1. A permanent crown (1) of a dental prosthesis supported by an implant, comprising: - a base (2) connected to a supporting part, which is an abutment connected to the implant, and - an overlay (3) having an occlusal surface (4) and secured to a base (2), wherein the base (2) performs the function of a gum former and has a contact surface designed with the possibility of attaching the overlay (3) to it with a geometric closure and having at least one protrusion (14) or at least one depression (5, 6, 7).

2. A permanent crown according to item 1, in which the overlay (3) is made in the form of a separate part having a contact surface aligned with the contact surface of the base (2) and secured to the base (2) by means of cement.

3. A permanent crown according to claim 2, in which the contact surface of the pad (3) has at least one protrusion (8, 9, 10, 13) or at least one depression (15).

4. A permanent crown according to claim 3, in which at least one projection (8, 9, 10) or at least one depression (5, 6, 7) is made crosswise.

5. A permanent crown according to claim 1, in which the overlay (3) is formed by a permanent filling formed on the contact surface of the base (2) using a bond.

6. A permanent crown according to one of items 1-5, in which a through hole (I) is made, passing through the base (2) and the overlay (3) to provide access to the supporting part.

7. A permanent crown according to one of items 1-6, in which the base (2) and the overlay (3) are made in such a shape that the overlay (3), after it is secured to the base (2), covers the base from above, or from above and in front, or from above and in front and on the sides.

8. A permanent crown according to one of items 1-7, in which at least the base (2) is made of zirconium.

9. A method of dental prosthetics using an implant and a permanent crown (1) according to one of paragraphs 1-8, characterized in that: - an implant is installed in the patient’s jaw, - after installing the implant and the supporting part, the base (2) of the permanent crown is installed on the supporting part, - the period of osseointegration necessary for the implant to take hold is maintained, - after the period of osseointegration, an overlay is fixed to the base (2) (3) permanent crown.

10. The method according to item 9, characterized in that during the period of osseointegration, the contact surface of the base (2) is covered with a temporary filling.

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