Dental prosthesis element comprising a micro-structured surface and a surface treatment

Abstract

Dental prosthesis element comprising a microstructured surface and a surface treatment. Dental prosthesis element (1) comprising a body (4) having a microstructured surface (14), and a coating (15) covering the microstructured surface, the coating being intended to come into contact with epithelial tissue (12) and / or connective tissue (13), the coating comprising zirconium nitride. Figure for abbreviation: Figure 1

Description

Title of the invention: Dental prosthesis element comprising a micro-structured surface and a surface treatment. Technical field of the invention

[0001] The invention relates to a dental prosthesis component comprising a micro-structured surface and a surface treatment adapted to form an effective bio-seal. The invention also relates to a method for manufacturing such a dental prosthesis component. Prior art

[0002] Dental restoration allows for the creation of artificial dentures for a partially or totally edentulous patient. Generally, dental restoration relies on the integration of at least one implant into the patient's bone structure. To place an implant, an incision is made in the gum to access the bone structure, which is then drilled through, and the implant is screwed into the bone. A temporary phase of osseointegration of the implant and healing of the gum then takes place before a dental abutment is fixed to the implant and a final prosthetic element, or dental crown, is cemented onto the abutment. The final prosthetic element is customized, adapted to the patient's anatomy and the tooth to be replaced, to achieve a result as close as possible to the ideal natural dentition.

[0003] A temporary prosthetic element is generally fixed to the implant while the implant integrates with the bone structure through osseointegration and the gum heals around the temporary prosthetic element. The temporary prosthetic element, also called a healing cap, can also be a custom-made element, adapted to the patient's anatomy. Most often, the temporary prosthetic element is a standard element, chosen from a range of temporary prosthetic elements based on the type of tooth being treated and the available space around the implant.

[0004] Furthermore, oral hygiene is particularly important for a patient fitted with a temporary or permanent prosthetic. During the healing phase, good oral hygiene is essential to allow the gums to heal quickly and painlessly. Subsequently, once the permanent prosthesis is fitted, good oral hygiene remains crucial to prevent infection and the need for further intervention on an area that has already been artificially treated.

[0005] More than 800 species of bacteria colonize the oral mucosa. These bacteria generally reside at the interface between the teeth and the gums and in dental plaque. The attachment of bacteria and the formation of plaque are detrimental to hygiene. In the case of a natural tooth, the junctional epithelium is directly connected to the tooth surface, forming an effective biological barrier against bacterial invasion thanks to an adhesion complex called the epithelial attachment apparatus, which includes the internal basal lamina and the hemidesmosome. When a natural tooth is replaced by a prosthetic element, whether temporary or permanent, the biological barrier formed by the junctional epithelium is less effective, increasing the risk of infection. Presentation of the invention

[0006] The object of the invention is to provide a dental prosthesis remedying the above disadvantages and improving on known dental prostheses of the prior art.

[0007] More specifically, a first object of the invention is a dental prosthesis element preventing the attachment of bacteria to its surface, and allowing the formation of an effective biological seal with the gum to reduce a risk of bacterial colonization. Summary of the invention

[0008] The invention relates to a dental prosthesis element comprising a body having a micro-structured surface, and a coating covering the micro-structured surface, the coating being intended to come into contact with an epithelial tissue and / or a connective tissue, the coating comprising zirconium nitride or titanium nitride or titanium nitrocarbide.

[0009] The body may comprise titanium or may be made of titanium.

[0010] The micro-structured surface may include a roughness between 0.4 pm and 1 pm inclusive according to ISO4287 and ISO25178 standards.

[0011] The micro-structured surface may include a set of striations extending around an axis in which the dental prosthesis element extends.

[0012] The body may include a first portion comprising said micro-structured surface and said coating, and a second portion intended to emerge from a gum, the second portion comprising a smooth surface devoid of microstructuring.

[0013] Said coating can also cover the smooth surface of the second portion.

[0014] The body may include a third portion comprising an interface intended to cooperate with a dental implant.

[0015] The dental prosthesis element may be a healing element intended to be temporarily attached to a dental implant during a healing period following the placement of the implant.

[0016] The invention also relates to a method for manufacturing a dental prosthesis component as defined above, the manufacturing method comprising: - the supply of a body, then - micro-structuring of a body surface, in particular by milling, then - the deposition of a coating comprising zirconium nitride or titanium nitride or titanium nitrocarbide on the micro-structured surface, in particular by physical vapor phase deposition. Presentation of the figures

[0017] These objects, features and advantages of the present invention will be described in detail in the following description of a particular embodiment, given by way of non-limiting example, in relation to the accompanying figures, among which:

[0018] Fig. 1 is a schematic view of a dental prosthesis element according to a first embodiment of the invention, the dental prosthesis element being fixed to an implant and comprising a surface in contact with a gum.

[0019] Fig. 2 is a perspective and exploded view of the implant, the dental prosthesis element according to the first embodiment of the invention, and a fixing screw for fixing the dental prosthesis element to the implant.

[0020] Fig. 3 is a microscopic photograph of a microstructured surface of a dental prosthesis element according to an embodiment of the invention.

[0021] The [Fig.4] is a roughness graph of the micro-structured surface of the [Fig.3].

[0022] Figure 5 is a photograph of a dental cavity after the removal of an element of dental prosthesis according to the first embodiment of the invention. Figure 6 is a schematic view of a dental prosthesis element according to a second embodiment of the invention, the dental prosthesis element being fixed to an implant and comprising a surface in contact with a gum. Detailed description

[0023] Figure 1 schematically illustrates a dental prosthesis element 1 according to an embodiment of the invention. The dental prosthesis element 1 is fixed to an implant 2, which is itself screwed into the bone structure of a patient. The dental prosthesis element 1 is also at least partially surrounded by a gingiva 3. The dental prosthesis element 1 extends along an axis X corresponding to a principal elongation axis of the implant 2.

[0024] According to the embodiment presented, the dental prosthesis element 1 is a healing element, also called a "healing cap." The dental prosthesis element 1 is therefore intended to be temporarily installed in a patient's mouth, for example, for a period of a few months, during the osseointegration phase of the implant 2 and the healing of the gingiva 3, before being replaced by a definitive prosthetic element such as a crown. The invention, which will be described in relation to a temporary dental prosthesis element, could to be transposed to a definitive dental prosthesis element, for example to a crown intended to be sealed to an abutment itself screwed to implant 2, and / or to an abutment screwed to the implant.

[0025] The dental prosthesis element 1 is also clearly visible in [Fig. 2]. It comprises a body 4, preferably monolithic. According to a preferred embodiment, the body 4 comprises or is made of titanium. The body 4 may, for example, be made of grade 2 or 4 titanium, or of a Ta6V titanium alloy, i.e., titanium filled with 6% aluminum and 4% vanadium. Alternatively, other materials could be considered as replacements for titanium, for example, polyetheretherketone (PEEK), zirconium, a titanium-zirconium alloy, a titanium-niobium alloy, or tantalum. Titanium and its alloys, however, have the advantage of being particularly strong and relatively simple to process.

[0026] The body 4 includes a central opening 5 for receiving a fixing screw 6. The fixing screw 6 extends along the X-axis through the opening 5. The fixing screw 6 includes a screw head 6.1 for bearing against an edge extending inside the opening 5, and a threaded portion 6.2 for cooperating with a corresponding threaded opening provided in the implant 2. The body 4 may advantageously have an anatomical shape, similar to the shape of a definitive dental prosthesis. An anatomical shape may be characterized by a shape different from a shape resulting from rotational symmetry about the X-axis. An anatomical shape allows the gingiva to heal in a shape substantially corresponding to the shape of the definitive dental prosthesis, thus avoiding further trauma to the gingiva during the installation of the definitive dental prosthesis.

[0027] Alternatively, other forms of the body 4 of the dental prosthesis element 1 could be considered. For example, the body 4 could be without an opening and include a threaded portion intended to cooperate directly with a corresponding threaded opening provided in the implant 2. Such an embodiment avoids the need for a fixing screw. In this case, the body 4 preferably has rotational symmetry about the X-axis so that it can be screwed and unscrewed in the implant 2 without damaging the gingiva.

[0028] According to the embodiment presented, the body 4 can be divided into several portions: a first portion 7 is intended to come into contact with the gingiva 3. A second portion 8, or apex portion 8, is intended to emerge from the gingiva 3. Finally, the body 4 comprises a third portion 9 including an interface 10 intended to cooperate with the implant 2, in particular to be inserted into a central opening of the implant 2. Said interface 10 may in particular include a sealing cone intended to bear against the implant and / or a locking means rotating like a hexagonal section cooperating with a correspondingly shaped housing provided in the implant. The first section 7 is an intermediate section of the dental prosthesis element 1: it is positioned between the second section 8 and the third section 9 along the X axis.

[0029] As mentioned previously, according to an alternative embodiment, the interface 10 could include a threaded portion intended to cooperate directly with the implant 2. According to another embodiment, the body 4 could be devoid of a summit portion 8 and be intended to be completely covered by the gingiva.

[0030] With reference to [Fig. 1], the gingiva 3 comprises an epithelial tissue 12 and a connective tissue 13 extending beneath the epithelial tissue 12. The epithelial tissue 12 includes, in particular, a sulcular epithelium 12.1 and a junctional epithelium 12.2. The epithelial tissue 12 and / or the connective tissue 13 are intended to come into contact with the dental prosthesis element 1 to form a biological seal that prevents bacteria from penetrating deeper into the gingiva and reaching the implant area 2. In this particular case, it is mainly the first portion 7 of the body 4 that extends opposite the epithelial tissue 12 and the connective tissue 13.

[0031] According to the invention, at least a part of the body 4 of the dental prosthesis element 1 intended to come into contact with an epithelial tissue or a connective tissue, in this case the first portion 7 of the body 4, comprises a micro-structured surface 14, and a coating 15 covering the micro-structured surface 14.

[0032] The microstructured surface 14 is a surface provided with microreliefs, in particular on the order of micrometers. As illustrated in [Fig. 3], the microreliefs may include parallel striations 16. The striations preferably extend perpendicularly to the X-axis. Each striation 16 therefore has a substantially annular shape around the first portion 7. Each striation thus forms a micro-barrier that extends across the passage of bacteria that would descend along the first portion 7 towards the implant 2. [Fig. 4] is a graph measuring the roughness of the microstructured surface 14 covered by the coating 15. To establish this graph, a point can be moved along the microstructured surface perpendicular to the striations, i.e., parallel to the X-axis. The position of the point is recorded as it is moved. Alternatively, a similar non-contact measurement method can be considered.Each peak in the resulting graph corresponds to a striation. The 16 striations can thus be spaced between 0.05 mm and 0.2 mm apart, for example, approximately 0.1 mm. The 16 striations can have a height between 0.5 µm and 1.5 µm, for example, approximately 1 µm. The roughness can preferably be between 0.4 µm and 1 µm inclusive, following ISO 4287 and with surface roughness parameters according to ISO 25178. Furthermore, and . As can be seen in [Fig.3], the micro-structured surface 14 may also include microreliefs 17 arranged along each striation 16. In particular, each striation 16 may be intersected at regular intervals by a microrelief 17.

[0033] Advantageously, the micro-structured surface is limited to the first portion 7. The second portion 8 and the third portion 9 of the body 4 are preferably not micro-structured, i.e., these portions are generally smooth. In any case, the second portion 8 and the third portion 9 are smoother than the first portion 7. They thus comprise a standard surface finish for a dental prosthesis component. The absence of micro-structuring on the second portion 8 reduces the risk of bacterial plaque accumulation, maintains an optimal aesthetic appearance, and ensures comfortable contact with oral tissues. The absence of micro-structuring on the third portion 9, in particular, helps maintain a good seal between the implant 2 and the dental prosthesis component 1.

[0034] In the event that the dental prosthesis element is intended to be completely buried under the gum, its upper surface, which extends at least roughly perpendicularly to the X axis, could also be micro-structured and covered with the coating 15.

[0035] According to a preferred embodiment, the micro-structured surface 14 is obtained by milling and / or turning the body 4. For example, the body 4 can be held by means of its interface 10, and a milling cutter rotating about an axis parallel to the X-axis can be applied against the periphery of the first portion 7 of the body. The cutter can be, for example, a micro ball cutter with a radius between 0.05 mm and 0.2 mm inclusive. Such an embodiment is simple to implement and makes it possible to produce striations 16 parallel to each other and perpendicular to the X-axis. This method also makes it possible to produce microreliefs 17 aligned along lines parallel to the X-axis, as shown in [Fig. 3]. Alternatively, the micro-structured surface 14 could also be obtained by knurling the body 4, i.e. by applying a knurled wheel or in other words a toothed wheel to the surface of the body 4.The use of a roller allows for the creation of cross-hatched grooves on the surface of body 4. Alternatively, other micro-structuring methods could be considered, for example, surface micro-structuring by laser beam or other electromagnetic beams with sufficient power, surface micro-structuring by chemical etching, or by electrodeposition. As yet another example, the dental prosthesis element 1 could be obtained by molding, and micro-reliefs could be incorporated into the mold used to manufacture the dental prosthesis element.

[0036] The coating 15 comprises zirconium nitride, or is made of zirconium nitride, that is to say, it then comprises exclusively zirconium nitride. Zirconium nitride is a chemical compound composed of zirconium (Zr) and nitrogen (N). Zirconium nitride has the advantage of being very hard and exhibiting excellent biomedical compatibility. The coating thickness can preferably be between 1 µm and 4 µm inclusive.

[0037] Advantageously, the coating 15 does not erase the underlying microstructure. Thus, the microstructured surface 14 covered by the coating 15 still exhibits a certain smoothed roughness. This surface has the advantage of being less aggressive to the gingiva, since it is smoothed by the coating 15. This roughness improves the physical fixation of the epithelial tissue 12, particularly the junctional epithelium 12.1, and the connective tissue 13. The epithelial tissue 12 and the connective tissue 13 then adhere more easily to the dental prosthesis element 1. This creates a more effective biological seal around the dental prosthesis element. The surface microstructure combined with a zirconium nitride coating thus provides a highly effective biological barrier against bacteria.This helps maintain particularly healthy tissues around the dental prosthesis and promotes gum healing. It also contributes to maintaining the proper bone structure around the implant and encourages bone growth around it. When the dental prosthesis is a temporary one, it helps improve and / or accelerate the osseointegration process.

[0038] The coating 15 can cover only the first portion 7 of the body 4. Alternatively, the coating 15 can also cover the second portion 8 and / or the third portion 9, or even cover the entire body 4. Thus the second portion 8 and / or the third portion 9 also benefit from increased hardness and biomedical compatibility.

[0039] The coating 15 can advantageously be deposited on the body 4 by physical vapor deposition, a process also known as PVD. This process consists of evaporating a source material, in this case zirconium nitride, under vacuum so that it is deposited on the surface of a part, in this case the body 4.

[0040] According to one embodiment of the invention, the zirconium nitride coating could be replaced by a titanium nitride coating. Titanium nitride is a chemical compound consisting of titanium (Ti) and nitrogen (N). The titanium nitride coating would then cover the micro-structured surface 14 of the body 4 as defined above.

[0041] According to another embodiment of the invention, the zirconium nitride coating could be replaced by a titanium nitrocarbide coating. Titanium nitrocarbide is a chemical compound consisting of titanium (Ti), carbon (C), and nitrogen (N). The titanium nitrocarbide coating would then cover the surface micro-structured 14 of body 4 as defined previously. Titanium nitrocarbide advantageously has a pink color like the natural color of the gingiva 3. Such a coating makes the dental prosthesis element 1 more discreet in the event that part of the micro-structured surface with the coating 15 remains visible after placement in a patient's mouth.

[0042] The use of the dental prosthesis element 1 described above reduces the risk of inflammation of the soft tissues of the gingiva in contact with it and stimulates the vascularization of these tissues. Figure 5 was taken after the removal of the dental prosthesis element 1 at the end of the healing and osseointegration period. The gingiva 3 can be seen to be very healthy and well vascularized.

[0043] Figure 6 illustrates a dental prosthesis element 1' according to a second method of the invention. According to this second embodiment, the dental prosthesis element 1' is a dental crown, that is, a "definitive" dental prosthesis element. The dental prosthesis element 1' is not intended to be removed from the patient's mouth, except, of course, in the event of a new medical problem requiring treatment. The dental prosthesis element 1' is cemented, that is, bonded, to an abutment 18', which is itself fixed, notably screwed, to the implant 2'. Unlike the prosthesis element 1 described previously, the dental prosthesis element 1' does not include a terminal opening. However, the dental prosthesis element 1' also includes a body with a micro-structured surface 14' and a coating 15' covering the micro-structured surface 14'. The 15' coating is also intended to come into contact with epithelial tissue and / or connective tissue of the gingiva 3'.Similarly, the coating 15' comprises zirconium nitride, titanium nitride, or titanium nitrocarbide. All features and options previously described in relation to the healing element 1 are applicable to the dental prosthesis element 1'. According to this second embodiment, the dental prosthesis element 1' has an anatomical shape that mimics the natural shape of the replaced tooth. The micro-structured surface 14' and the coating 15' can be applied to a generally frustoconical portion of the dental prosthesis element 1' that is covered by the gingiva 3'.

Claims

Demands

1. Dental prosthesis element (1) comprising body (4) having a micro-structured surface (14), and a coating (15) covering the micro-structured surface, the coating being intended to come into contact with epithelial tissue (12) and / or connective tissue (13), the coating comprising zirconium nitride.

2. Dental prosthesis element (1) comprising body (4) having a micro-structured surface (14), and a coating (15) covering the micro-structured surface, the coating being intended to come into contact with epithelial tissue (12) and / or connective tissue (13), the coating comprising titanium nitride or titanium nitrocarbide.

3. Dental prosthesis element (1) according to any one of the preceding claims, characterized in that the body (4) comprises titanium or is made of titanium.

4. Dental prosthesis element (1) according to any one of the preceding claims, characterized in that the micro-structured surface (14) comprises a roughness between 0.4 pm and 1 pm inclusive according to ISO4287 and ISO25178 standards.

5. Dental prosthesis element (1) according to any one of the preceding claims, characterized in that the micro-structured surface (14) comprises a set of striations (16) extending around an axis (X) in which the dental prosthesis element extends.

6. Dental prosthesis element (1) according to any one of the preceding claims, characterized in that the body comprises a first portion (7) comprising said micro-structured surface (14) and said coating (15), and a second portion (8) intended to emerge from a gum, the second portion comprising a smooth surface devoid of micro-structuring.

7. Dental prosthesis element (1) according to the preceding claim, characterized in that said coating (15) also covers the smooth surface of the second portion.

8. Dental prosthesis element (1) according to any one of the preceding claims, characterized in that the body (4) comprises a third portion (9) comprising an interface (10) intended to cooperate with a dental implant.

9. Dental prosthesis element (1) according to any one of the preceding claims, characterized in that it is a healing element intended to be temporarily attached to a dental implant (2) during a healing period following the placement of the implant.

10. A method for manufacturing a dental prosthesis element (1) according to any one of the preceding claims, comprising: - supplying a body (4), then - micro-structuring a surface of the body, in particular by milling, then - depositing a coating (15) comprising zirconium nitride or titanium nitride or titanium nitrocarbide on the micro-structured surface (14), in particular by physical vapor phase deposition.

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