Dental abutment and dental assembly for multiple restorations

Abstract

A multi-unit dental abutment (1) comprising a first hole (14) passing through it for a screw for connecting with a dental implant, a base part (11) arranged at a first end to be coupled to the implant and traversed by the first hole, a support part (12) arranged at a second end, mainly formed by a conical surface (13), the support part (12) being provided with a second hole (15). The support part (12) comprises a positioning surface for positioning a restoration abutment (2). The positioning surface is joined to the conical surface (13) at its wider diameter end and is provided with a plurality of grooves (16) parallel to the axial axis of the second hole. The dental abutment may comprise a zirconium nitride (ZrN) coating with a layer thickness of between 1 and 10 µm.

Description

[0001]

[0002] “Dental abutment and dental assembly for multiple restorations”

[0003] Technical sector of the invention

[0004] The present invention relates to a dental abutment of the type known in the dental sector as a "multi-unit" or "multi-unit" abutment. This type of dental abutment is screwed onto a dental implant and, in turn, acts as a support for the placement of a rehabilitation abutment above it. Once several dental assemblies, each consisting of a "multi-unit" dental abutment and a rehabilitation abutment, have been placed on corresponding implants, inserted at different angles into the maxillary bone or mandible, a prosthetic superstructure, also known as a bar superstructure, bar with full prosthesis, or prosthetic platform, is placed on the rehabilitation abutments. This type of multiple rehabilitation is especially indicated for edentulous patients who need to fully or partially rehabilitate a dental arch.

[0005] According to another aspect, the invention also relates to the dental assembly formed by the aforementioned “multi-unit” dental abutment and the rehabilitation abutment.

[0006] Background of the invention

[0007] Multi-unit abutments are well-known in the dental sector for enabling multiple prosthetic rehabilitation, especially in fully or partially edentulous patients. In these cases, dental implants cannot always be inserted ideally following an apical-coronal insertion axis, i.e., with a vertical insertion, but rather the implants are inserted at different inclinations into the mandible or maxillary bone. These different inclinations must be compensated for by multi-unit abutments, which are screw-connected to the implants and serve as a support for the placement of rehabilitation pieces or abutments. In turn, the bar superstructure or prosthetic platform is placed on top of these abutments, which carry the prosthetic pieces that reproduce part of the denture being restored.

[0008] In fact, the various inclinations in the insertion of the implants are compensated, depending on the magnitude of each inclination angle, by angled or angled “multi-unit” abutments, or by straight “multi-unit” abutments to which angled rehabilitation abutments are fitted.

[0009] The basic function of angled multi-unit abutments is to correct and level the rehabilitation platform. Angled multi-unit abutments and / or sets consisting of straight multi-unit abutments with angled rehabilitation abutments correct any unwanted angulation that may occur in inserted dental implants, either due to placement errors or because the patient's anatomical conditions require tilted placement.

[0010] Currently known are angled "multi-unit" abutments that consist of a lower or base portion for fixing to the head of a dental implant by means of a first abutment-implant fixing screw, and an upper or support portion, with an essentially conical boundary surface for coupling, by means of a second prosthesis-abutment fixing screw, a rehabilitation abutment on which a dental prosthesis is mounted. The angled "multi-unit" abutment also comprises a first through-hole for the passage of the abutment-implant connection screw, and a second threaded hole, arranged through the upper or support portion of the angled abutment, in communication with the first through-hole and whose respective axial axes form an angle with each other.

[0011] Patent documents EP0323421-A2 and US5662474-A, and utility model ES1148559U show angled “multi-unit” pillars as described above.

[0012] The abutments described above are indicated for multiple dental restorations. In multiple dental restorations, it is necessary to insert a common superstructure that fits simultaneously onto all the restoration abutments placed on the multi-unit abutments, which are in turn attached to the implants. The common superstructure is a rigid structure; it cannot be bent or its shape altered to fit the spatial orientation or inclination in which the restoration abutments have been placed. The multi-unit abutments or restoration abutments must be placed in the same orientation so that the superstructure fits in a single collation direction and is leveled, ensuring that the restoration supported by the superstructure is functionally and aesthetically correct in the patient's oral cavity.

[0013] To achieve this, a series of multi-unit abutments and rehabilitation abutments with different angulations are required, to adapt them specifically to each of the spatial conditions, the angulation of the inserted implants, and the shape of the maxillary structure in which the multiple rehabilitation will be performed. The objective is to select, for each location defined by the insertion of an implant, the combination of abutments with the inclination that allows the superstructure to be inserted in all locations simultaneously. This leaves virtually no room for improvisation or correction once the abutment assemblies have been placed on the implants.

[0014] Thus, the need for multi-unit abutments is evident, as they make it easier to achieve the correct orientation direction for the placement of the superstructure at each implant location, allowing for correct orientations without having to unscrew the abutments from the implants.

[0015] Explanation of the invention

[0016] In order to achieve the objectives set out, a dental abutment is disclosed, of the "multi-unit" type, comprising a first through hole for the passage through which a screw for connecting the dental abutment to a dental implant passes, a base portion arranged at a first end, configured for coupling to a dental implant and crossed by the first through hole, and a support portion arranged at a second end opposite the first, configured mostly by a conical surface whose diameter narrows towards the end, the support portion being provided with a second hole arranged through the conical surface.

[0017] Essentially, the dental abutment object of the invention is characterized in that the support portion of the dental abutment comprises a positioning surface for positioning a restoration abutment on the support portion, wherein the positioning surface is connected to the conical surface at its larger diameter end. The positioning surface is provided with a plurality of grooves, each groove extending in a direction parallel to the axial axis of the second hole.

[0018] It is important to clarify that in this text, when reference is made to a dental abutment, or just to abutment, this refers to a "multi-unit" abutment, and when reference is made to a rehabilitation abutment, this refers to the abutment that is placed on top of the "multi-unit" abutment.

[0019] The dental abutment object of the invention may be, according to one embodiment, a straight abutment, in which the axial axis of the first hole and the axial axis of the second hole are aligned. According to another embodiment, the dental abutment may be an angled or angled abutment, i.e., one in which the axial axis of the second hole of the support part forms an acute angle with the axial axis of the first hole.

[0020] The use of a straight or angled dental abutment will depend on the inclination of the implants inserted in each case. For example, angled multi-unit dental abutments have angles between 30° and 17°.

[0021] According to another characteristic of the dental abutment of the invention, the positioning surface is a cylindrical surface whose perimeter comprises at least one perimeter section in which the plurality of grooves are arranged, the grooves being separated from each other by sections of the cylindrical surface.

[0022] According to another characteristic of the dental abutment of the invention, in the plurality of grooves, the grooves are equidistant from each other.

[0023] According to another characteristic of the dental abutment of the invention, the plurality of grooves extends in a perimeter section of the positioning surface, the section covering an angle between 90° and 360° with respect to the axial axis of the second hole, preferably between 170° and 190°, and more preferably covering an angle of 180°.

[0024] As regards the morphology of the grooves, these can have a cross-section, that is, according to a cut perpendicular to the length of the grooves, in the form of a semicircle, curve, rectangle, square, triangular, dovetail, etc.

[0025] According to another feature of the dental abutment of the invention, the first through-hole and the second through-hole are in communication, the inlet of the first through-hole being arranged on one side of the conical surface of the support portion and the outlet being at the end of the base portion. Furthermore, the plurality of slots are arranged at least in a perimeter section of the positioning surface located opposite the inlet of the first through-hole.

[0026] According to another feature of the invention, the support portion of the angled dental abutment comprises a support platform for supporting a restoration abutment. The support platform is provided with a first, flat support surface arranged between the positioning surface and the base portion, and protrudes beyond the perimeter of the projection of the positioning surface. The first support surface may be perpendicular to the axial direction of the second hole, or may form an acute or obtuse angle with respect to said axis.

[0027] According to a preferred embodiment, the support platform is further provided with a second, flat support surface, arranged adjacent to the positioning surface and projecting beyond the perimeter of the projection of the positioning surface. The second support surface may be perpendicular to the axial axis of the second hole, or may form an acute or obtuse angle with respect to said axis. The first support surface and the second support surface are connected by a side wall with a conical or cylindrical surface.

[0028] According to a preferred embodiment of the dental abutment of the invention, the abutment has a coating comprising zirconium nitride (ZrN), preferably with a zirconium nitride layer thickness of 1 to 10 µm. Preferably, the coating consists solely of zirconium nitride. This zirconium nitride coating reduces or eliminates the proliferation of bacterial plaque, thereby helping to prevent peri-implantitis.

[0029] Peri-implantitis can affect the tissues surrounding an integrated dental implant, resulting in a loss of bone support. That is, the abutment and implant may suffer peri-implantitis caused by an infection in the connective tissue of both. The zirconium nitride coating on the abutment can prevent the onset of infection, and therefore, the dental abutment will not be the cause, as it prevents the infection.

[0030] Although the zirconium nitride coating can be applied to the entire dental abutment, it is preferable to apply it to at least the sections of the dental abutment that come into contact with gingival tissue.

[0031] Preferably, the dental abutment has the zirconium nitride coating on the intermediate portion of the dental abutment, which separates the base portion, arranged at the first end of the dental abutment, from the support portion, arranged at the second end of the dental abutment. That is, the base portion and the support portion do not have this zirconium nitride coating, or at least, it is not considered necessary.

[0032] Regarding the intermediate portion of the dental abutment, which is a section of the abutment that comes into contact with gingival tissue, the zirconium nitride coating can be applied to this entire portion or to selected areas.

[0033] Metals, such as titanium, can be coated with good adhesion within the coating and between the coating and the metal, particularly by sputtering. In sputtering, the material is detached from a cathode (target) and precipitated onto a substrate. The coating is carried out in a vacuum chamber in the presence of an inert gas such as argon (gas flow sputtering, GFS). Reactive sputtering allows the introduction of an additional gas that reacts with the ions released from the target. The coatings obtained with this process are ceramic in nature if oxygen or nitrogen is introduced.

[0034] Preferably, in the invention, the dental abutment, or a portion thereof, is coated with such a reactive gas flow atomization in a vacuum chamber in the presence of nitrogen or oxygen. In this regard, reference is made to document DE 19958643 C1 and the techniques described therein for coating turbine blades with zirconium oxide. The target material is metallic zirconium alloyed with up to 10% by weight of yttrium. The dental abutment or abutments are placed on a heated substrate support.

[0035] To prevent the coating from also precipitating on parts of the pillar that are not to be coated, such as the holes, they are protected in a known way.

[0036] Zirconium oxide can be mixed with a metal oxide in a known manner. Such a polycrystalline "stabilized" zirconium oxide contains, for example, up to 10% by weight of yttrium oxide (Y2O3) and also, if appropriate, aluminum oxide (AI2O3), magnesium oxide (MgO), calcium oxide (CaO), or several of these oxides. The stabilized zirconium oxide layer can be produced, for example, by simultaneous sputtering of zirconium and yttrium in the presence of oxygen. If "zirconium" is referred to hereinafter, it can be present as a metal, as well as a nitride or oxide, containing up to 10% by weight of yttrium, generally 5 to 10% by weight.

[0037] Notwithstanding the above, other sputtering methods are also suitable for preparing the desired coating, for example, DC sputtering, HF sputtering, magnetron sputtering and ion radiation sputtering, including electron beam evaporation, with GFS sputtering being preferred.

[0038] The zirconium nitride coating on dental abutments has a color ranging from yellow to gold, such that even thin coatings can cover the gray color of the metal as desired. This zirconium nitride coating typically has a layer thickness of 1 to 10 µm, depending on the desired color intensity and the thickness of the extremely hard zirconium nitride layer.

[0039] From a physiological perspective, zirconium nitride has the advantage not only of extraordinarily high hardness, which increases the coating's abrasion resistance, but also of extraordinarily good physiological compatibility. Zirconium nitride, like zirconium oxide, promotes bonding to gingival tissue. Both zirconium nitride and zirconium oxide adopt the texture produced by the metal processing operation and transfer it to the surface. Connective tissue cell colonization occurs over the entire surface of the dental abutment in contact with the gum. In the case of the dental abutment object of the invention, the support portion, on which the plurality of grooves and the sections of the cylindrical surface that separate them are arranged, is hidden and therefore does not come into contact with the gum.

[0040] This reduces or prevents peri-implantitis, which occurs in multiple dental abutments. It also results in a reduction in platelet accumulation.

[0041] According to a second aspect of the invention, a dental assembly for multiple restorations is disclosed. The assembly object of the invention is characterized in that it comprises a dental abutment as described above according to the first aspect of the invention, and a restoration abutment. The restoration abutment is configured by a hollow body open at two ends and whose cavity comprises a section of interior wall with a conical surface corresponding to the conical surface of the support portion of the dental abutment, followed by a section of smooth interior wall in which at least one projection is provided that projects therefrom towards the interior of the cavity and whose dimensions are such that the projection can be fitted tightly within any of the slots of the plurality of slots with which the positioning surface of the support portion is provided.According to another feature of the assembly object of the invention, according to a preferred embodiment, in the rehabilitation pillar, the smooth interior wall section on which at least one protrusion is provided is a cylindrical interior wall section. Preferably, the smooth interior wall section is provided with a single protrusion. However, other configurations with more than one protrusion are not ruled out. The morphology of this protrusion corresponds to the morphology of the grooves, such that the protrusion can fit within the grooves.

[0042] According to a preferred embodiment of the assembly object of the invention, the angled dental abutment comprises the support platform for supporting a rehabilitation abutment described above, which is provided with a first flat support surface, and the rehabilitation abutment is a tubular body, the lower end of which is configured with a flat edge parallel to the first support surface.

[0043] According to another characteristic of the assembly object of the invention, the rehabilitation abutment is a tubular body in which the free end, this being the one that is furthest from the prosthetic abutment when the projection is fitted into one of the slots, has an outer surface whose contour forms an angle with the axial axis of the second hole of the dental abutment when the projection is fitted into one of the slots.

[0044] Brief description of the drawings

[0045] The accompanying drawings illustrate, by way of non-limiting example, a first and a second preferred embodiment of the dental abutment, of the “multi-unit” type, and a first embodiment of a dental assembly that it forms together with a rehabilitation abutment, which are objects of the invention, also showing the rehabilitation abutment of the assembly separately. In said drawings: Fig. 1 is a perspective view of a first embodiment of the dental abutment object of the invention, according to an angled embodiment; Fig. 2 is a top view of the dental abutment of Fig. 1 , according to the direction of the axial axis of the second hole of the angled dental abutment; Fig. 3 is a sectional view of the assembly object of the invention of which the dental abutment of Fig. 1 forms a part, according to a vertical section containing the axial axes of the first through hole and the second hole of the angled dental abutment; Figs.4 and 5 are perspective views of the rehabilitation abutment of the assembly in Fig. 3; Fig. 6 is a bottom view of the rehabilitation abutment in Fig. 4; Figs. 7 to 9 are schematic representations of two of the placement stages of the assemblies object of the invention and of the prosthetic superstructure for a multiple rehabilitation, Figs. 8 and 9 belonging to the same stage, seen from opposite sides; Fig. 10 is a schematic view of the assembly in Fig. 3 in two different orientation positions of the rehabilitation abutment with respect to the dental abutment; Fig. 11 is a perspective view of a second embodiment of the dental abutment similar to that of Fig. 1 but with the difference that in this case the dental abutment comprises a zirconium nitride (ZrN) coating; Fig.12 shows the diagram of a coating structure that includes a rotating substrate support plate, to carry out the coating of the second embodiment of the dental abutment object of the invention.

[0046] Detailed description of the drawings

[0047] Fig. 3 shows a dental assembly 100 for multiple restorations, consisting of a "multi-unit" type dental abutment 1, in this case angled, and a restoration abutment 2, also angled and configured to be coupled to the dental abutment 1 in a position where one piece is oriented relative to the other. In multiple restorations, a bar superstructure 3 or prosthetic platform, such as that shown in Figs. 7 to 9, is placed on the restoration abutment 2, which supports the prostheses of one or more arches. The angled dental abutment 1 and the restoration abutment 2 are made of grade 5 titanium.

[0048] As can be seen especially in Figs. 1 and 2, the angled dental abutment 1 comprises a base portion 11 arranged at a first end, the lower end in the drawings, configured for coupling to a dental implant (not shown), a support portion 12 arranged at a second end opposite the first end, the upper end in the drawings, on which the rehabilitation abutment 2 is placed, and a transition portion integrally joined to the base portion 11 and to the support portion 12.

[0049] The base portion 11 of the angled dental abutment 1 has a configuration consistent with the end portion of the dental implant to which it is coupled, depending on whether it is an internal or external connection implant. In the example shown, the base portion 11 has an essentially cylindrical outer end surface provided with longitudinal grooves, followed by a conical surface, corresponding to the configuration of the internal cavity of the upper outer portion of the dental implant, in this case an internal connection, to which the angled dental abutment 1 is intended to be coupled.

[0050] The base portion 11 of the angled dental abutment 1 is traversed by a first through-hole 14, which is intended for the passage therethrough of a connecting screw (not shown) between the dental abutment 1 and the dental implant. The axial direction of the first hole 14, shown in Fig. 3 as a dash-dot line, is parallel to the longitudinal direction in which the dental implant extends. The first hole 14 comprises a narrowing above which the screw head is seated.

[0051] In Fig. 3 it can be seen how the inlet of the first through hole 14 is arranged on one side of the support part 12 (see also Fig. 2), and the outlet at the end of the base part 11. According to the embodiment shown in the figures, the head of the screw connecting the dental abutment 1 to the dental implant would rest on a seat located in the transition part of the dental abutment 1, specifically just above the narrowing of the section of the first hole 14 shown in Fig. 3.

[0052] Depending on the morphology of the dental implant on which the prosthetic rehabilitation is to be carried out, the base part 11 of the dental abutment 1 may comprise other configurations, for example, presenting a polygonal outer surface (pentagon, hexagon, octagon, etc.), a multi-lobular outer surface, a conical outer surface, a polygonal, multi-lobular or conical inner cavity, etc.

[0053] As for the support part 12 of the angled dental abutment 1, it is provided with a second threaded hole 15, the axial axis of which forms an acute angle with the axial axis of the first hole 14. This angle between the axial axes of the holes is the reason why the dental abutment 1 shown in the drawings is an angled abutment, rather than a straight one. The support part 12 is mostly configured by a conical surface 13 the diameter of which narrows towards the end opposite the base part 11. The second hole 15 is indicated for the passage through which a screw (not shown) is used to fix the rehabilitation abutment 2 to the dental abutment 1.

[0054] The first through hole 14 and the second hole 15 are connected to each other. The respective axial axes of the first hole 14 and the second hole

[0055] 15 can range, depending on the model of the angled dental pillar 1, between 17° and 30°.

[0056] In the embodiments shown in the figures, the conical surface 13 is divided into two sections of different heights and conicity angles, the apical section having a lower height and a greater conicity than the other section of the conical surface 13. Following the end of the section of the conical surface 13 having a larger diameter, the support part 12 has a positioning surface, which is characterized by being provided with a plurality of grooves.

[0057] 16 in which each slot 16 extends in a direction parallel to the axial axis of the second hole 15.

[0058] As can be seen in Figs. 1 and 2, the positioning surface is a cylindrical surface 17 whose perimeter comprises at least one peripheral section in which the plurality of grooves 16 are arranged. The cylindrical surface 17 and the conical surface 13 do not complete a 360° surface, since the entrance of the first through hole 14, as mentioned above, since the dental abutment 1 is angled, is located on one side of the conical surface 13 and its exit at the end of the base portion 11. In the figures shown, the grooves 16 are equidistant from each other and are separated by sections of the cylindrical surface 17. This allows for precise control of the orientation of the rehabilitation abutment 2 when it is fitted onto the dental abutment 1, as will be explained later.

[0059] The plurality of grooves 16 may be arranged around the entire perimeter of the cylindrical surface 17 or only along one or more portions of said perimeter. Thus, the plurality of grooves 16 may extend over a perimeter section of the positioning surface, said perimeter section encompassing an angle between 90° and 360° with respect to the axial axis of the second hole 15. Preferably, the perimeter section encompasses an angle between 170° and 190°, as shown in Fig. 2, in which the perimeter section provided with the plurality of grooves 16 is approximately 180° and is located on the side opposite the entrance to the first through hole 14. In the example shown, the grooves 16 of the plurality are separated from one another by an angular distance of 18° originating at the center of the second hole 15.

[0060] The dental abutment 1 further comprises a support platform for supporting the restoration abutment 2, arranged downstream of the positioning surface. In the embodiment shown in the figures, the support platform is provided with a first support surface 18, which is flat and perpendicular to the axial axis of the second hole 15, and with a second support surface 19, parallel to the first support surface 18, which is located downstream of the positioning surface. Both the first support surface 18 and the second support surface 19 project beyond the projection of the positioning surface, considering their projection on a plane perpendicular to the axial axis of the second hole 15. The first support surface 18 and the second support surface 19 are connected by a side wall with a conical surface.

[0061] According to other embodiments not shown, the planes of the first support surface 18 and the second support surface 19 may form an acute or obtuse angle with respect to the axial axis of the second hole 15, and may be joined by a side wall of cylindrical or polygonal prismatic configuration.

[0062] In any case, the first support surface 18 is configured in correspondence with the flat edge 28 of the lower end of the rehabilitation pillar 2, shown in Figs. 4 to 6, so that said flat edge 28 can rest stably on the first support surface 18.

[0063] The rehabilitation pillar 2, shown in Figs. 3 to 6, is a hollow body open at two ends and externally formed by two tubular sections 20a and 20b, which in this case have respective non-cylindrical, but rather obliquely conical, exterior surfaces. The rehabilitation pillar 2 has an externally angled configuration, since the contours of the tubular sections 20a and 20b, in this case, the generatrices of the cones of each tubular section 20a and 20b, form an angle with each other. This can be clearly seen in the longitudinal section of the assembly 100 shown in Fig. 3 according to a diametrical section plane of the second hole 15. The left-hand contours of the two sections 20a and 20b are not aligned, but form an angle, and the left-hand contours also form an angle, although different from that of the other side, because the conical surfaces belong to oblique cones.The final orientation of the contour of the tubular section 20b (the section furthest from the dental abutment 1 in the assembly position of the assembly 100), must be such that it allows the insertion of the bar superstructure 3 in the insertion direction 31, which allows the placement of said superstructure on all the rehabilitation abutments 2 at the same time, as will be explained later.

[0064] It can be observed in Fig. 3 that the cavity of the rehabilitation abutment 2, from its open upper end to its open lower end, is formed by different sections that allow the introduction through the upper end of a screw with a threaded end (not shown) by means of which the rehabilitation abutment 2 will be joined by a screwed connection to the dental abutment 1 when screwed into the second axial hole 15.

[0065] At first glance it can be seen that the rehabilitation abutment 2 has, approximately inside the second tubular section 20b, a cavity comprising a section of inner wall with a conical surface 23 corresponding to the conical surface 13 of the support part 12 of the dental abutment 1. This section is followed by a section of smooth cylindrical inner wall 21, of a height corresponding to the cylindrical surface 17, on which a projection 22 is provided projecting from said wall towards the interior of the cavity, as can be seen in Figs. 4 to 6. The projection 22 extends vertically from a flat surface 29 which is intended to rest on the second support surface 19 of the dental abutment 1 when the latter is coupled with the rehabilitation abutment 2.

[0066] The dimensions of the projection 22 are such as to allow it to be fitted tightly into any of the slots 16 of the plurality of slots with which the positioning surface of the support part 12 of the dental abutment 1 is provided. Particularly, the contour of the cross section of the projection 22 has a slightly flared, flattened curve shape (see Figs. 4 to 6).

[0067] In this way, the assembly 100 formed by the dental abutment 1 and the rehabilitation abutment 2 allows for a broader control of the position of the rehabilitation abutment 2 with respect to the dental abutment 1, and consequently, of the orientation of the tubular section 20b with respect to the axial axis of the dental implant.

[0068] The smaller the separation distance between two consecutive slots 16 of the plurality of slots provided in the positioning surface, the more precision can be achieved in orientation.

[0069] Fig. 10 schematically represents two of the multiple positions that the rehabilitation abutment 2 can adopt on the dental abutment 1 of Figs. 1 and 2, due to the fact that the projection 22 has been fitted first in a slot 16, position shown in solid lines, and then in another slot 16 separated from the other by approximately 180°, position shown in dashed lines. This would be the result of first fitting the projection 22 in the slot 16a, and then, having disengaged it, pulling the rehabilitation abutment 2 upwards, to fit the projection in the slot 16b of Fig. 2, which is located approximately 180° from the slot 16a. The position in solid lines determines one insertion direction 31 of the bar superstructure 3, and the position in dashed lines determines another insertion direction 3T distinct from the other.

[0070] The assembly 100 allows the orientation between the two pillars to be corrected quickly and easily, so that all the rehabilitation pillars 2 are oriented according to the same insertion direction 31, this direction being the one that allows the bar superstructure 3 to be inserted at the same time on the upper tubular sections that form part of the rehabilitation pillars 2.

[0071] Fig. 7 represents a situation in which four dental implants have been inserted into the mandible or maxillary bone of a patient. These dental implants may have different longitudinal directions and different inclinations. In order to carry out multiple rehabilitation procedures so that the different inclinations of the implants do not hinder the effective placement of a multiple prosthesis with good aesthetics, multi-unit dental abutments 1 have been coupled to the corresponding dental implants. It can be seen that the dental abutments 1 placed leave the succession of slots 16 visible. In Fig. 8, the respective rehabilitation abutments 2 have been placed on the dental abutments 1, fitting the projections 22 of each one into one of the slots 16 of each dental abutment 1.

[0072] For its part, the bar superstructure 3, which supports the multiple prosthesis, comprises a series of hollow caps 30 whose cavities must be coupled to the rehabilitation abutments 2, fitting into the upper tubular sections 20b. The bar superstructure 3 is a relatively rigid structure, which means that the branches that join the caps 30 cannot bend too much and the caps cannot be forced too much to rotate on their longitudinal axes to adapt to the orientation of each of the sections 20b. All of the caps 30 are identical with regard to their internal cavity, and are inserted onto the rehabilitation abutments 2 according to a single insertion direction 31, shown in Fig. 9. If, for example, the dentist, in the situation of Fig.8 and 9, warns that the tubular section 20b of one or more of the rehabilitation abutments 2 is oriented in such a way that it cannot fit into the cavity of the corresponding cap 30, and that it should be slightly rotated a few more degrees around the axial axis of the second hole 15 of the corresponding dental abutment 1, it will be sufficient to proceed to pull the rehabilitation abutment 2 upwards (in the opposite direction to the dental implant) until the projection 22 is disengaged from the slot 16 in which it is inserted, and replace the projection 22 in another slot 16 such that the final orientation given to it is the one followed by the insertion direction 31. The plurality of slots 16 in which the projection 22 can fit offers the possibility of adopting multiple positions for the same set 100 and with remarkable precision.Thus, all the rehabilitation pillars 2 placed can be oriented according to the same insertion direction 31, which is what allows the bar superstructure 3 to be correctly placed on the assemblies 100. By making small adjustments, placing some projections 22 in specific slots 16, all the rehabilitation pillars 2 will be able to fit into the cavities of the caps 30, achieving the appropriate leveling of the bar superstructure 3 for the support of the multiple prosthesis and its transmission of forces to the inserted implants.

[0073] It is worth mentioning that the dental abutment 1 does not have to be angled, since the possibility of correcting the position of the rehabilitation abutment 2 on it can also occur in dental abutments 1 whose support part 12 comprises the positioning surface provided with a plurality of grooves 16.

[0074] A second embodiment of dental abutment 1 is shown in perspective in Fig. 11, which differs from that shown previously in that it comprises a zirconium nitride (ZrN) coating with a layer thickness of 1 to 10 µm. It can be seen that in this second embodiment, the zirconium nitride coating is applied to the intermediate portion 10 of the dental abutment 1 that separates the base portion 11 from the support portion 12. In the case shown, the zirconium nitride coating is applied to the entire intermediate portion 10. In other embodiments not shown, it could be applied to selected areas of the intermediate portion 10.

[0075] Thus, the zirconium nitride coating partially covers the dental abutment 1. It mainly covers the area that will be in contact with the gum, that is, the part of the connection that remains inside the implant, the base part 11, which is not coated. The support part 12 is also not coated, because this part will be covered by the upper dental structure that is later placed on the dental abutment 1. Ultimately, the area of ​​the dental abutment 1 on which the zirconium nitride coating is applied is the intermediate part 10.

[0076] The zirconium coating is applied by sputtering, preferably applied by spraying with reactive gas flow in a vacuum chamber in the presence of nitrogen.

[0077] Fig. 12 shows a schematic of a coating structure including a rotating substrate support plate. The coating chamber is a polygonal vacuum system with a chamber volume of 200 l, which is equipped with a horizontally processing GFS line source provided with zirconium-yttrium metal targets (92.2:7.8% by weight). In carrying out the reactive process, zirconium oxide partially stabilized with yttrium is ejected while oxygen is introduced into the process; zirconium nitride (+yttrium nitride) is ejected when nitrogen is added. A second sputtering source (Ti source) makes it possible to deposit an additional titanium adhesion layer. Inlets for the reactive gases oxygen and nitrogen are provided near the zirconium source.

[0078] A substrate support plate is used to hold the substrate, which is heated from the back. A ceramic heat radiator allows the substrate to be heated to temperatures of up to 400°C. 0 C, which are monitored by means of a thermocouple in contact with the support plate.

[0079] The gases used in the process are argon, which is used for material transfer, as well as oxygen and nitrogen, which are used as reactive gases. Both require a very high purity of at least 99.99%. To apply the coatings, the pillars, arranged on the substrate support, are first treated with glow discharge in the presence of argon to remove surface impurities and oxide layers. This is followed by the application of an intermediate layer of zirconium nitride, while additional nitrogen is introduced into the process.

Claims

1. A dental abutment (1) comprising a first through hole (14) for passing through a screw for connecting the dental abutment (1) to a dental implant, a base portion (11) arranged at a first end, configured for coupling to a dental implant and traversed by the first through hole (14), a support portion (12) arranged at a second end opposite the first, configured mostly by a conical surface (13) whose diameter tapers towards the end, and wherein the support portion (12) is provided with a second hole (15) arranged through the conical surface (13), characterized in that the support portion (12) of the dental abutment (1) comprises a positioning surface for positioning a rehabilitation abutment (2) on the support portion (12), wherein the positioning surface is joined to the conical surface (13) by its end of larger diameter,provided with a plurality of slots (16) in which each slot (16) extends in a direction parallel to the axial axis of the second hole (15)., 2. The dental abutment (1) according to claim 1, characterized in that it is a straight abutment, in which the axial axis of the first hole (14) and the axial axis of the second hole (15) are aligned.

3. The dental abutment (1) according to claim 1, characterized in that it is an angular abutment, in which the axial axis of the second hole (15) of the support part (12) forms an acute angle with the axial axis of the first hole (14).

4. The dental abutment (1) according to any one of the preceding claims, characterized in that the positioning surface is a cylindrical surface (17) whose perimeter comprises at least one perimeter section in which the plurality of grooves (16) are arranged, the grooves (16) being separated from each other by sections of the cylindrical surface (17).

5. The dental abutment (1) according to any one of the preceding claims, characterized in that in the plurality of grooves (16), the grooves (16) are equidistant from each other.

6. The dental abutment (1) according to any one of the preceding claims, characterized in that the plurality of grooves (16) extends in a peripheral section of the positioning surface, the section covering an angle between 90° and 360° with respect to the axial axis of the second hole (15), preferably between 170° and 190°.

7. The dental abutment (1) according to any one of claims 4 to 6 when depending on claim 3, characterized in that the first through hole (14) and the second hole (15) are in communication, the inlet of the first through hole (14) being arranged on one side of the conical surface (13) of the support part (12) and the outlet at the end of the base part (11), and in that the plurality of grooves (16) is arranged at least in a peripheral section of the positioning surface located opposite the inlet of the first through hole (14).

8. The dental abutment (1) according to any one of the preceding claims, characterized in that the support part (12) comprises a support platform for supporting a rehabilitation abutment (2), the support platform being provided with a first flat support surface (18) between the positioning surface and the base part (11), protruding from the perimeter of the projection of the positioning surface.

9. The dental abutment (1) according to claim 8, characterized in that the first flat support surface (18) is perpendicular to the axial axis direction of the second hole (15), or forms an acute or obtuse angle with respect to the axial axis direction of the second hole (15).

10. The dental abutment (1) according to claim 8 or 9, characterized in that the support platform is further provided with a second support surface (19) that is flat and is arranged next to the positioning surface of the support part (12), projecting beyond the perimeter of the projection of the positioning surface, the first support surface (18) and the second support surface (19) being connected by a side wall with a conical or convex surface. cylindrical.

11. The dental abutment (1) according to claim 10, characterized in that the second support surface (19) is perpendicular to the direction of the axial axis of the second hole (15), or forms an acute or obtuse angle with respect to the direction of the axial axis of the second hole (15).

12. The dental abutment (1) according to any one of the preceding claims, characterized in that it has a coating comprising zirconium nitride (ZrN).

13. The dental abutment (1) according to claim 12, characterized in that the coating comprising zirconium nitride (ZrN) has a zirconium nitride layer thickness of 1 to 10 pm.

14. The dental abutment (1) according to any one of claims 12 to 13, characterized in that the coating comprising zirconium nitride is applied at least, totally or partially, to the intermediate part (10) of the dental abutment (1) separating the base part (11), arranged at the first end of the dental abutment (1), from the support part (12), arranged at the second end of the dental abutment (1).

15. The dental abutment (1) according to claim 14, characterized in that the coating comprising zirconium nitride is applied to the entire intermediate part (10) of the dental abutment (1) that separates the base part (11) from the support part (12).

16. The dental abutment (1) according to any one of claims 12 to 15, characterized in that at least the sections of the dental abutment (1) that come into contact with gingival tissue are coated by the coating comprising zirconium nitride.

17. The dental abutment (1) according to any one of claims 12 to 16, characterized in that the coating is formed solely by zirconium nitride.

18. The dental abutment (1) according to any one of claims 12 to 17, characterized in that the zirconium nitride coating is applied by cathodic sputtering.

19. The dental abutment (1) according to claim 18, characterized in that the coating comprising zirconium nitride is applied by spraying with a reactive gas flow in a vacuum chamber in the presence of nitrogen.

20. A dental assembly (100) for multiple rehabilitations, characterized in that it comprises a dental abutment (1) according to any one of claims 1 to 19 and a rehabilitation abutment (2) configured by a hollow body open at two ends and whose cavity comprises a section of inner wall with a conical surface (23) in correspondence with the conical surface (13) of the support part (12) of the dental abutment (1), followed by a section of smooth inner wall (21) in which at least one projection (22) is provided projecting therefrom towards the interior of the cavity and whose dimensions are such that the projection (22) is fittable with adjustment within any of the slots (16) of the plurality of slots with which the positioning surface of the support part (12) is provided.

21. The dental assembly (100) according to claim 20, characterized in that the smooth inner wall section (21) on which at least one projection (22) is provided is a cylindrical inner wall section.

22. The dental assembly (100) according to claim 20 or 21, characterized in that the support part (12) of the dental abutment (1) comprises a support platform for supporting the rehabilitation abutment (2), the support platform being provided with a first flat support surface (18) between the positioning surface and the base part (11), protruding from the perimeter of the projection of the positioning surface, and in that the rehabilitation abutment (2) is a tubular body, the lower end of which is configured with a flat edge (28) parallel to the first support surface (18).

23. The dental assembly (100) according to any one of claims 20 to 22, characterized in that the rehabilitation abutment (2) is a tubular body in which the free end, this being the one that is furthest from the dental abutment (1) when the projection (22) is fitted into one of the slots (16), has an outer surface whose contour forms an angle with the axial axis of the second hole (15) of the dental abutment (1) when the projection (22) is fitted into one of the slots (16).

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