The present invention relates to an angled monobloc dental implant.

According to the present view of dentistry, one of the options for replacing missing teeth is a dental implant implanted in the patient's jawbone and a removable or fixed prosthesis attached thereto. The most common implants are two-piece implants, consisting of an implant body that can be placed in the jaw (usually fixed by screwing) and an implant head that can be screwed into the implant body. By design, two-piece dental implants have a number of disadvantages, such as loosening of the fixation between the parts and the colonisation of bacteria the joint, which can lead to inflammation. To overcome these disadvantages, the use of single-piece, so-called monobloc dental implants for tooth replacements has recently started, which are characterised by the fact that they are made of a single block of material, such as titanium. A special type of monobloc implants are so- called angular implants, in which the longitudinal axes of the implant body and the extra-bony neck and head meet at a certain angle. These implants are particularly effective for the replacement of maxillary teeth, where post-removal bone loss results in an unfavourable (protruding) maxillary geometry, and therefore the use of conventional axisymmetric implants is not an option in such unfavourable anatomical conditions. Such an angular implant is described, for example, in US patent US 2018/0140393, where the conventional threaded body portion and the head portion, which is at an appropriate angle to the body, are formed from a single metal block using computer-aided milling (CAD/CAM). Patent application US 2016/020002 also describes a customized monobloc dental implant specifically designed for crown fixation, where the body and head portions are designed such that the centre of the head axis is aligned with the centre of the occlusal surface of the tooth to be replaced. Monobloc implants are usually made of titanium, which has the structural strength and hypoallergenic properties required for tooth replacement.

The specificity of angled monobloc implants is that they are either individually manufactured or the implant is selected (from a set of prefabricated implants of different sizes and designs) and subsequently (individually) processed according to the anatomical conditions of the tooth to be replaced and the prosthesis site. This involves the creation of a 3-dimensional virtual model of the environment of the replacement tooth using an imaging technique (usually CBCT), in which the "virtual implant" is also displayed. Based on the modelled data, the implant is then fabricated using known material processing techniques (e.g. CNC or CAD-CAM milling, casting, 3-dimensional printing, etc.) to produce the implant corresponding to the virtual model. It follows from the above procedure that the implant must be placed in the position (depth, angular position, etc.) corresponding to the virtual model. Although state-of-the-art solutions are known that facilitate the creation of the implant hole in the bone (in particular the adjustment of the hole angle), these so-called surgical drilling templates do not provide any support for the surgeon to adjust the axial position of the implant head and the desired parallelism of the implant head with the other implant heads.

It is recognised that during implantation, the correct axial position of the head of the angular monobloc implant (matching the virtual model) and the desired parallelism of the head of the angular monobloc implant to the heads of the other implants cannot always be predicted by visual inspection alone.

It is also recognised that, as yet, no state-of-the-art angular monobloc implants have been described that would assist in placing the implant in the correct position.

It is an object of the present invention is to provide an angular monobloc dental implant that is free from the drawbacks of the prior art solutions. In particular, it is an object of the present invention to provide an angular monobloc dental implant that allows easy determination of the final position of the implant during implantation.

The essence of the invention is that the angular monobloc implant with body, neck and head portions comprises a visual indicator at the boundary between the body and the neck portion, which, when the implant is in the implanted position, faces the vestibular direction of the implant (10) and provides a reference point for the surgeon.

According to the invention, this object is achieved by an angled monobloc implant according to claim 1 .

Preferred embodiments of the invention are defined in the dependent claims.

Further details of the invention will be described with reference to the accompanying drawings. In the drawing

Figure 1 a is a schematic view of an exemplary embodiment of an angled monobloc dental implant according to the invention,

Figure 1 b is a schematic view of another exemplary embodiment of an angled monobloc dental implant according to the invention, the

Figure 2a is a perspective view of the angled monobloc dental implant of Figure 1 a in the implanted state,

Figure 2b is a partial cross-sectional side view from the direction of the oral cavity showing the angled monobloc dental implant in the implanted state as shown in Figure 1 a, and

Figure 2c is a top view of the angled monobloc dental implant in the implanted state as shown in Figure 1 a.

Figure 1 a is a schematic view of an exemplary embodiment of an angled monobloc dental implant 10 according to the invention. The implant 10 is monobloc (one-piece), i.e., formed from a single element, such as a single piece of metal, using known machining technologies (e.g., computer-controlled milling, casting, 3D printing, etc.) as known to the person skilled in the art. The implant 10 is preferably made of titanium, but other bioinert materials commonly used in implantology, e.g. metal alloys, bioinert ceramics, may be used, as is apparent to the person skilled in the art.

The implant 10 according to the invention comprises a body 10a and a head portion 10c, and a neck portion 10b located between the body 10a and the head portion 10c. In the context of the present invention, the body 10a is understood to be the part of the implant 10 implanted in the bone 20, while the neck portion 10b and the head portion 10c are understood to be the parts of the implant 10 protruding from the bone 20. The neck portion 10b is a through section connecting the body 10a and the head portion 10c, which is in contact with the patient's gingiva when the implant 10 is in its final position. The shapes of the body 10a, neck portion 10b and head portion 10c may have the usual shapes for one-piece implants, depending on the site of the implant 10 and the patient's anatomy. In the exemplary embodiment shown in Figure 1 a, the body 10a has a downwardly tapered diameter to facilitate implantation of the implant 10. The body 10a may also be provided with elements to improve fixation, such as spikes or screw threads (not shown in the figures), as is known to the skilled person. The implant 10 according to the invention is angled, i.e. the body 10a is arranged along a first longitudinal axis T1 and the neck portion 10b and the head portion 10c are positioned along a second longitudinal axis T2, such that the first and second longitudinal axes T1 , T2 are angled with respect to each other (see Figures 1 a and 1 b). The angle enclosed by the longitudinal axes T 1 and T2 is determined by the anatomy of the tooth to be replaced and the location and environment of the tooth replacement, i.e. the implant 10 according to the invention is customized. Thanks to the angled design, the ideal axial position of the crown fixed to the implant 10 and the angular misalignment of the longitudinal axis T1 of the body 10a can be compensated to the desired extent, i.e. during implantation, the longitudinal axis T1 can be set perpendicular to the chewing surface of the replacement tooth even when the body 10a can only be fixed obliquely to the bone 20 (e.g. due to the position of adjacent teeth), as shown in Figures 2a and 2b.

The implant 10 according to the invention comprises a visual indicator 30 formed at the boundary 40 of the body 10a and the neck portion 10b, facing the vestibular direction V of the implant 10 when the implant 10 is implanted. The boundary 40 is an imaginary or actual boundary line (e.g., marked by a different surface treatment of the body 10b and the neck 10b) separating the neck portion 10b from the body 10a, which, in the implanted state of the implant 10, is substantially aligned with the bone surface 22 at the site of the tooth replacement. It is noted that in practice, with different surface treatments of body 10a and neck 10b (e.g. roughened body 10a, polished neck 10b), the polished surface may extend 0,5-1 mm beyond the neck 10b towards body 10a. It is noted that with different surface treatments of the body 10a and the neck portion 10b (e.g., roughened body 10a, polished neck portion 10b), the polished surface may in practice extend 0.5-1 mm from the neck portion 10b toward the body 10a. In this way, the roughened surface may not be visible in case of a subsequent bone dissection. Therefore, the boundary 40 of the body 10a and the neck portion 10b does not necessarily coincide with the surface treatment. In the context of the present invention, the vestibular direction V is understood to be the direction outwardly from the dental arch at the implanted implant 10 towards the vestibulum oris, as is known to the person skilled in the art. In other words, the vestibular direction V is the outward perpendicular direction at the tangential point of the dental arch S of the outermost point of the implant 10 facing the oral cavity, as illustrated in Figure 2c.

The visual indicator 30 can be any naked-eye marker on the boundary 40 that faces in the vestibular direction V when the implant 10 is implanted. The indicator 30 may preferably be formed from the material of the implant 10, for example by etching, engraving, or other known machining techniques. In this way, there is no need to use foreign materials (e.g. paints). Of course, embodiments in which the indicator 30 is formed by painting on the surface of the implant 10 are also conceivable. For these embodiments, it is preferable to use bioinert paints which do not react with the patient's body, as is known to the skilled person. The indicator 30 according to the invention is located on the boundary 40, so that it also partially overlaps the body 10a and the neck portion 10b, respectively, as shown in Figures 1a and 1 b. The shape and size of the indicator 30 is chosen so as to be clearly suitable for indicating the vestibular direction V, for example in the form of a dot as shown in Figure 1 a or a cross in Figure 1 b, but of course other shapes (e.g. triangle, star, etc.) can be envisaged as appropriate. The centre of the indicator 30, e.g. the centre of the dot or cross, indicates the vestibular direction V and also the location of the boundary 40, i.e. the boundary 40 preferably passes through the centre of the dot or cross. In this way, the indicator 30 not only provides the surgeon with guidance on the correct angular position (about the T1 axis) of the implant 10, but also on the correct insertion depth of the implant 10.

The body 10a has an outer surface 12a, the neck portion 10b has an outer surface 12b and the head portion 10c has an outer surface 12c. The shape of the surfaces 12a, 12b, 12c may be e.g. conical, truncated conical, cylindrical, band or other. In a possible embodiment, the surfaces 12a, 12c of the body 10a and head portion 10c are roughened, and the surface 12b of the neck portion 10b is smoothly polished. In the context of the present invention, a roughened surface is understood to be a surface having surface roughness (protrusions and indentations measured in micrometers) due to manufacturing or post-manufacturing surface treatment. By contrast, a smooth polished surface is one where these surface irregularities have been removed either during or after manufacture, or where the surface has been formed without such irregularities from the outset. Roughened surfaces 12a, 12c are preferably sandblasted, but roughened surfaces 12a, 12c may be formed by, for example, chemical etching or, for example, by so-called SLA - Sand-blast, Large grit, Acid-etch technology, as is known to the skilled person.

In the following, a possible method of making an angled monobloc dental implant 10 according to the invention is described. In a first step, one or more scanned images are taken of the surroundings of the tooth to be replaced, including the jaw and soft tissues such as the gum 20. The one or more scans are preferably taken using CBCT (Cone Beam CT), a common technique in dentistry, which can create a 3-dimensional virtual image of the bones at the site of the planned implant 10, as well as the root system of the surrounding teeth. From this data set, the 3- dimensional virtual model, a computer program can be used to provide the technician with images (different views) from which the dimensions of the customized implant 10 (e.g. size, angle subtended by the longitudinal axes T1 , T2, etc.) and the ideal placement position of the implant 10 can be determined. The virtual model can also be used to determine which part of the implant 10 will face in the vestibular direction V when implanted.

The implant 10 produced from the virtual model during production or the implant 10 selected from the kit after production are provided with the indicator 30 in such a way that the position of the indicator 30 corresponds to the vestibular direction V determined from the virtual model. Based on the position of the indicator 30 and the position of the boundary 40 separating the body 10a and the neck portion 10b, the surgeon can determine the implantation position of the implant 10, i.e. the position of the longitudinal axes T1 , T2, as well as the appropriate implantation depth of the implant 10 before starting the implant placement. The indicator 30 also provide a continuous reference during the implantation process, as they can be used to determine the exact axial position of the implant 10.

Various modifications to the above disclosed embodiments will be apparent to a person skilled in the art without departing from the scope of protection determined by the attached claims.