DENTAL SCREW

Abstract

Dental screw which can be inserted into a cavity of a patient's maxillary and/or mandibular bone, including a terminal portion that can be inserted into the cavity so as to fit within it and so as to engage a side wall thereof. The dental screw further includes a cervical portion, configured to engage an artificial tooth structure, and a central portion extending longitudinally between the terminal portion and the cervical portion. The central portion is shaped as a porous structure, particularly as a trabecular structure, to promote an intraosseous regrowth process. The dental screw is further characterised in that the terminal portion, the central portion and the cervical portion are made from a single piece.

Claims

1. A dental screw, which can be inserted into a cavity of a patient's maxillary and/or mandibular bone, comprising: a terminal portion that can be inserted into said cavity so as to engage a side wall thereof; a cervical portion configured to engage an artificial tooth structure; a central portion extending longitudinally between said terminal portion and said cervical portion and shaped as a porous structure, in particular as a trabecular structure, to promote intraosseous regrowth; wherein said terminal portion, said central portion, and said cervical portion are made from a single piece.

2. The screw according to claim 1, wherein said screw is made using an additive manufacturing technique.

3. The screw according to claim 1, wherein said central portion has a side surface at least partially equipped with a self-tapping thread configured to engage the side wall of said cavity.

4. The screw according to claim 3, wherein said self-tapping thread has a porous structure, in particular a trabecular structure.

5. The screw according to claim 3, wherein said terminal portion and said cervical portion have self-tapping threads at their corresponding side surfaces that are configured to engage the side wall of said cavity, wherein said self-tapping threads are connected together in order to define a single self-tapping thread extending between said terminal portion and said cervical portion.

6. The screw according to claim 1, wherein said cervical portion comprises a secondary screw thread.

7. The screw according to claim 1, wherein said cervical portion comprises a shaped seat configured to accommodate a tool for installing said screw in the cavity and/or to accommodate a connection portion of said artificial tooth structure, said shaped seat preferably has an octagonal conometric cross-section.

8. The screw according to claim 1, wherein said dental screw is made of a titanium-vanadium-aluminium alloy (Ti.sub.6Al.sub.4V).

9. The screw according to claim 1, wherein said dental screw has a basically circular cross-section and a shape that tapers from said cervical portion to said terminal portion.

Description

[0027] Such description will be set forth herein below with reference to the accompanying drawings, provided for merely indicative and therefore non-limiting purposes, wherein:

[0028] FIG. 1 shows a perspective view of the dental screw that is the object of the present invention;

[0029] FIG. 1A shows an enlargement of a detail of the dental screw in FIG. 1; and

[0030] FIG. 2 shows a front view of the dental screw object of the present invention.

[0031] With reference to the appended figures, 1 denotes a dental screw which can be inserted into a cavity of a patient's maxillary and/or mandibular bone, not shown in the appended figures.

[0032] The dental screw 1 comprises a terminal portion 2 which can be inserted into the cavity so as to engage a side wall thereof. In other words, the terminal portion 2 is shaped so as to come into contact with the side wall of the cavity without causing possible damage during insertion.

[0033] The dental screw 1 further comprises a cervical portion 3 configured to engage an artificial tooth structure such as a ceramic tooth. Preferably, the cervical portion 3 is recessed into the crestal bone of the patient and, in use, once the dental screw 1 is inserted within the patient's cavity, said cervical portion 3 is arranged so as to be accessible and, therefore, to accommodate the artificial tooth structure in a manner that will be described in detail below.

[0034] The dental screw 1 also comprises a central portion 4 extending longitudinally between the terminal portion 2 and the cervical portion 3 and shaped as a porous structure, in particular as a trabecular structure (FIG. 1A), to promote an intraosseous regrowth process.

[0035] FIG. 1A shows an embodiment of a possible three-dimensional distribution of the porous structure made according to the present invention for illustrative purposes, however the geometry of the inner “channels” making up the trabecular structure may have geometries that vary depending on design requirements and patient parameters.

[0036] Advantageously, the terminal portion 2, the cervical portion 3 and the central portion 4 are made from a single piece.

[0037] In other words, the terminal portion 2, the cervical portion 3 and the central portion 4 are made in such a way that the dental screw 1 has a continuous structure, i.e., a structure in which there is no mechanical interference, interlocking, form-fitting, welding and the like between the portions 2, 3, 4.

[0038] The fact that the dental screw is made 1 from a single piece makes it particularly strong in terms of mechanical properties and more durable in terms of service life. In known dental screws, the point where the central porous portion engages with the other two respective portions of the dental screw is a particularly critical point due to the porous structure and it is therefore more likely to break. In the case of the present invention, however, this drawback is substantially eliminated since portions 2, 3, 4 define a single body.

[0039] In other words, the fact of making the portions 2, 3, 4 composing the dental screw 1 from a single piece avoids having to assemble the portions 2, 3, 4 together by means of engagement and mechanical connections that may result in breakage and/or damage of the dental screw 1 due to the micro-movements reported in the known art.

[0040] Preferably, an additive manufacturing technique such as the Direct Melt Laser Sintering technique or the Electron Beam Melting technique is used to make portions 2, 3, 4 of the dental screw 1.

[0041] Such a technique also makes it possible to significantly reduce the time required to make the dental screw 1, thereby increasing the production rate.

[0042] The additive manufacturing technique, which works by adding material, also makes it possible to reduce the amount of material waste resulting from the processing itself, thus reducing the costs involved in making the dental screw 1.

[0043] Advantageously, the additive manufacturing technique also makes it possible to obtain a central portion 4 structure having a high degree of porosity. Such as aspect is particularly advantageous as it promotes and speeds up intraosseous tissue growth.

[0044] In the preferred embodiment, the central portion 4 of the dental screw 1, as well as the terminal portion 2 and the cervical portion 3, is made of a titanium, aluminium and vanadium alloy (Ti.sub.6Al.sub.4V).

[0045] Advantageously, this alloy, which is widely used in the orthopaedic sector, has mechanical properties that are far better than those of the titanium alloy, which is typically used for dental screws.

[0046] The possibility of creating a central portion 4 that is highly porous, and therefore as similar as possible to a real trabecular structure, also allows to better fix the dental screw 1 within the cavity.

[0047] Referring now to the enclosed figures, a detailed description of the portions 2, 3, 4 constituting the dental screw 1 that is the object of the present invention is provided.

[0048] As shown in FIG. 1, the terminal portion 2 comprises a side surface provided with a self-tapping thread 2a and a base surface 2b. The thread 2a allows the screw 1 to be screwed into the patient's cavity in such a way as to promote fixation of the dental screw 1 at a predetermined position in the cavity.

[0049] As visible from FIG. 2, the central portion 4 has a side surface at least partially provided with a self-tapping thread 4a configured to engage the side wall of the patient's cavity.

[0050] In detail, this self-tapping thread 4a also has a porous structure, in particular a trabecular structure.

[0051] Preferably, the self-tapping thread 4a placed on the central portion 4 has a pitch between 1.2 mm and 3.5 mm.

[0052] In other words, when the dental screw 1 is manufactured, the central portion 4 is made as a volume having a porous structure and provided, on a side surface, with a self-tapping thread 4a also having a porous structure.

[0053] This is a particularly advantageous aspect in that the self-tapping thread 4a obtained on the central portion 4 enables the dental screw 1, once positioned in the oral cavity, to firmly maintain this position.

[0054] This self-tapping thread 4a also makes the central portion 4 stronger and more robust and allows to apply a correct clamping pressure in the patient's cavity. In fact, by making a thread 4a also on the central portion 4 of the dental screw 1, it is possible to exert the correct pressure on the patient's cavity avoiding problems of bone necrosis and/or undesired movement of the dental screw 1 within the cavity.

[0055] In a preferred embodiment, the self-tapping thread 4a is the extension of the self-tapping thread 2a. As will be described hereinafter in detail, the cervical portion 3 is provided with a self-tapping thread 3a which is the extension of the self-tapping thread 4a of the central portion 4.

[0056] In other words, the self-tapping threads 2a, 3a and 4a constitute portions of a single self-tapping thread extending between the terminal portion 2 and the cervical portion 3.

[0057] Advantageously, thus, the self-tapping threads 2a, 3a, 4a define a single self-tapping thread which extends continuously around the terminal portion 2, the central portion 4 and the cervical portion 3.

[0058] Advantageously, a single thread prevents the dental screw 1 from undergoing micro-movements once installed in the patient's oral cavity.

[0059] In a preferred embodiment, the self-tapping threads 2a, 3a, 4a have the same pitch.

[0060] In a further possible embodiment, not shown, the self-tapping threads 2a, 3a, 4a have different pitches despite being portions of a single self-tapping thread.

[0061] Still referring to FIG. 1, there is shown the cervical portion 3 whose side surface comprises, in a position proximal to the central portion 4, the aforementioned self-tapping thread 3a configured to engage a wall of the patient's cavity. The cervical portion 3 also includes a secondary thread 3b in order to obtain a roughness near the patient's crestal bone.

[0062] Preferably the single self-tapping thread extends between the secondary thread 3b and the base surface 2b.

[0063] Preferably, the cervical portion 3 further comprises a shaped seat 3c configured to accommodate a tool for installing the dental screw 1 in the cavity.

[0064] Still more preferably, such shaped seat 3c has an octagonal conometric cross-section.

[0065] Said shaped seat 3c may further be configured to accommodate, after the dental screw 1 is placed in the cavity, a connection portion of the artificial dental structure so that the latter is constrained to the dental screw 1. In such a situation, the shaped seat 3c is, for example, made in such a way that the artificial tooth structure cannot perform any rotational movement around a longitudinal axis of the dental screw 1 itself, thus keeping the artificial tooth locked in position. The shaped seat 3c can also accommodate healing screws, MUAs and/or test posts for taking a dental impression.

[0066] According to a further aspect of the present invention, the dental screw 1 has a basically circular cross-section and a shape that tapers from the cervical portion 3 to the terminal portion 2.

[0067] In a further possible embodiment, not shown, the dental screw 1 has a substantially cylindrical shape.

[0068] The present invention achieves the intended purposes overcoming the drawbacks of the prior art.

[0069] In particular, the dental screw 1 is not subject to problems deriving from micro-movements due to the mechanical interferences between the portions 2, 3, 4 being the latter made from a single piece so that the dental screw 1 has a continuous structure.

[0070] As the dental screw 1 object of the present invention is made by means of an additive manufacturing technique, it allows the terminal portion 2, the central portion 4 and the cervical portion 3 to be made from a single piece and to be interconnected without interference and mechanical clearance.

[0071] Advantageously, the dental screw 1 thus has a continuous structure which is made layer by layer according to an additive technique which is typical of additive manufacturing.

[0072] The dental screw 1 is less subject to wear and break than the known screws made by assembling several portions.

[0073] The dental screw 1 is manufactured more quickly than the known art screws and is more cost-efficient as well.

[0074] By virtue of its central structure which is particularly similar to a real trabecular structure, the dental screw 1 object of the present invention, promotes and optimises the osseointegration process.

[0075] The dental screw 1 has better mechanical properties than the screws of the prior art.

[0076] The presence of the self-tapping thread 4a on the central portion of the dental screw 1 encourages to maintain the correct position of the screw 1 within the patient's oral cavity during the osseointegration process and allows the dental screw 1 to exert the correct pressure within the patient's cavity preventing the risk of necrosis, micro-movements and breakage of the trabecular porous structure from occurring.