WO2016139557A1

WO2016139557A1 - Modular reference system to determine space references on a dental guide device to guide a dental implantology procedure

Info

Publication number: WO2016139557A1
Application number: PCT/IB2016/050999
Authority: WO
Inventors: Luca TOLEDANO
Original assignee: Toledano Luca
Priority date: 2015-03-03
Filing date: 2016-02-24
Publication date: 2016-09-09

Abstract

A modular reference system for determining, on a diagnostic dental guide (24), space references to guide a dental implant procedure comprises: e) a first component (1), which is made from radio- transparent material and can be fixed in a preferred point (27) of the dental guide (24); f) a plurality of second components (2, 3) divided into reference components (2) made from radio-opaque material, all having the same dimensions, and spacer components (3) made from radio-transparent material, each second component (2, 3) comprising respective means of coupling (7-10) for the pack assembly of the second components (2, 3), alternating reference components (2) with spacer components (3); g) a portion (4) for coupling of the first component (1) comprising a surface for assembly of the pack of second components; h) a third component (13) comprising at least one first portion (14), which can be mounted on the coupling portion (4) with coupling means (15, 16) in place of the pack of second components (2, 3) and on which it is possible to mark the space references (22) that can be obtained from an analysis of a respective volumetric computerised tomography cross-section image of a maxillofacial complex including the dental guide (24) on which the pack of second components (2, 3) is fixed, and a second portion (17), which is perpendicular to and integral with the first portion (14); on the first (14) and second (17) portions of the third component (13) it being possible to mark two respective space references (22, 23) that can be obtained from an analysis of two respective volumetric computerised tomography cross-section images, at right angles to each other, of a maxillofacial complex including the dental guide, it being possible in these images to see the pack of second components (2, 3) according to respective views along two planes at right angles to each other.

Description

MODULAR REFERENCE SYSTEM TO DETERMINE SPACE REFERENCES ON A DENTAL GUIDE DEVICE TO GUIDE A DENTAL IMPLANTOLOGY PROCEDURE

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This invention concerns a modular reference system to determine space references on a diagnostic dental guide device, which are useful in guiding a dental implantology procedure .

Dental implantology consists of creating dental prostheses fixed to integrated bone implants which substantially consist of screws inserted in the bone, presenting respective threaded cavities for the mounting of components designed to stabilize mobile prostheses, or to support fixed prosthetic crowns for single teeth or bridges.

An implantology procedure is preceded by a diagnostic step which includes acquiring radiographic images by means of volumetric computed tomography and sometimes impressions in order to create study models and/or surgical devices to be used in the subsequent surgical operation. During the acquisition of radiographic images, a diagnostic dental device is often used, made from resin and reproducing the arch in which the implant will be inserted and on which one or more radio-opaque reference elements are positioned.

In general, the surgical operation foresees the steps of incising and elevating the gingiva from the bone to expose the area of bone in which the screws will be inserted, cutting the bone with special burs to prepare the screw housings and inserting the screws into these housings. Once the period of time necessary to achieve the desired stability has passed, the made-to-measure prostheses are screwed into the threaded cavities.

In order to reduce invasiveness and operating times, computer-guided techniques have been developed wherein fairly complex software programmes recreate a three- dimensional image of the bone structures of the maxillofacial complex on the basis of volumetric computerised tomography data, define virtual integrated bone implants inserted in housings oriented according to required directions and model surgical guide devices on the basis of virtual implants, using 3D printers

or numerical control burs.

The surgical guide device is equipped with bushings centered on the virtual implant insertion directions, according to the specifications foreseen by the company supplying the burs and implants. These bushings should make it possible to reproduce a preparation in the patient that corresponds exactly to what was decided when programming the surgery. The surgery is performed using dedicated surgical components, supplied by the manufacturing company and, therefore, fairly expensive. However, experience shows that the precision of positioning the guide and, consequently, the implant obtained with these guided implantology techniques, may be less than expected.

The aim of this invention is to create a reference system to determine space references on a dental guide that are able to guide a dental implantology procedure, and in particular a reference system to transform a diagnostic guide for computerised tomography into a surgical guide, this system being free of the above-mentioned drawbacks and, at the same time, being easy and economical to produce and use .

According to this invention, it provides a modular reference system to determine space references, on a diagnostic dental guide, that are able to guide a dental implantology procedure, according to what is defined in the accompanying claims.

In order to better understand the invention, a preferred embodiment will now be described as a non-binding example and with reference to the accompanying drawings in which:

- figures 1, 2, 3, 5, 18, 19, 20,. 21 and 22 show, according to relative prospective views, respective components of the modular reference system according to the invention;

figures 4 and 6 show respective assemblies of the components of figures 1 to 5 used in respective steps of a procedure for the acquisition of space references which precedes the guided surgery implantology procedure;

- figures 7 to 17 show various stages of the space reference acquisition procedure;

- figure 23 shows an assembly of the components shown in figures 18 to 22 together with the components of figure 6 for the transformation of the diagnostic dental guide into a surgical guide for guided surgical treatment; and

- figure 24 shows an assembly of the components shown in figures 18 to 20 together with additional components of the modular reference system, according to another embodiment of the invention.

- figures 25 and 26 show a schematic view of an example of the use of the system according to the invention;

- figures 27 and 28 show schematic views of an aiming system which makes use of a linear guide cooperating with a mobile guide fitted on the head of an instrument;

- figures 29 and 30 show schematic views of the use of a laser component fitted on the head of an instrument and designed to provide visual indications by means of a laser beam relative to the aiming direction.

With reference to figures 1 to 3, the modular reference system comprises a support component 1 (figure 1) made from radio-transparent material that can be fixed to the dental guide (not shown in figures 1-3) , and a plurality of components consisting of reference components 2 (figure 2) made from radio-opaque material, all of the same size, and spacer components 3 (figure 3) made from radio-transparent material. In particular, the material from which the reference components 2 are made is PVC (polyvinyl chloride) , radio-opaque to the radiation used for volumetric computerised tomography, and the material from which the support component 1 and the spacer components 3 are made is P MA (polymethyl methacrylate ) , radio-transparent to the aforesaid radiation.

With reference to figure 1, the support component 1 comprises a central portion 4 in the shape of a rectangular plate, presenting six holes 5, and specifically six through holes, arranged in two rows of three, and two anchoring portions 6 positioned along the two long sides of the central portion 4 for fixing the support component 1 in one of the two points of a dental guide. In particular, each anchoring portion 6 is thicker than the central portion 4 and can be adapted, by a mechanical process, to the shape of a required portion of the dental guide in order to be fixed in a required portion by glueing.

In the example shown in figures 2 and 3, the reference components 2 have the same plate shape and thickness and the spacer components 3 have the same shape and size as the reference components 2. Each component 2, 3 comprises a respective trio of through holes , 8 with parallel axes and orthogonal to the faces of the component 2, 3 and a respective trio of cylindrical pins 9, 10 with parallel axes and perpendicular to one face 11, 12 of a component 2, 3 in such a way as to engage the holes 8, 7 of another component 3, 2 to allow the pack-assembly of the components 2, 3, alternating reference components 2 and spacer components 3.

Advantageously, the holes of the hole trio 7, 8 are positioned at the points of a first triangle and the pins of the pin trio 9, 10 are positioned at the points of a second triangle inverted with respect to the first triangle.

The central portion 4 of the support component 1 is the same width and length as a reference component 2. The size of the central portion 4 and the difference in thickness between this portion and the anchoring portions 6 define a housing for the coupling with the reference component 2. This coupling is made possible by an arrangement of the holes 5 wherein three of them can be engaged by three pins 9 of the reference component 2 at the head of the pack of components 2 and 3 so that the pack can be mounted on the central portion 4 as shown in figure 4. Thus, the holes 7, 8 and the pins 9, 10 of the components 2, 3 define male-female type coupling means that allow the pack-assembly of the components 2 and 3, alternating the reference components 2 and the spacer components 3 and the mounting of the pack- assembly of the components 2 and 3 on the central portion 4 with the reference component 2 at the head of the pack coupled to the central portion 4.

With reference to figures 5 and 6, the modular reference system of the invention also comprises a transfer component 13 (figure 5) which can be mounted on the central portion 4 of the support component 1 in place of the pack of components 2 and 3 (figure 6) in order to transfer, to the support component 1, information relative to the implant direction obtained from an analysis of one or more volumetric computerised tomography images. In particular, the transfer component 13 is designed to be marked with at least one space reference obtainable from an analysis of a volumetric computerised tomography cross- section image of a maxillofacial complex (not shown) which includes a dental guide on which the support component 1 with the pack of components 2 and 3 is fixed, in such a way that the pack of components 2 and 3 is visible in the image, as will be explained in detail herebelow. The space reference marked on the guide can be used to guide a dental implantology procedure performed using this guide.

The transfer component 13 comprises at least a first portion 14 with the same size and features as the reference component 2 so that it can be coupled with the central portion 4 of the support component 1 in the same way as the reference component 2. In particular, the first portion 14 presents three holes 15 and three pins 16 identical to the holes 7 and pins 9 of the component 2. In more detail, the transfer component 13 is L-shaped, that is to say it also comprises a second portion 17. perpendicular to and integral with an edge 18 of the first portion 14. For reasons of construction simplicity and to facilitate its use, the second portion 17 is substantially identical to the first portion 14, that is to say it is the same size, and has the same holes (indicated by 19 in figure 5) and pins (not visible in the figure) as the first portion 14.

The inner faces 20 and 21 of the portions 14 and 17, that is to say the faces opposite to those from which the respective pins protrude, are designed to be marked with respective reference marks obtainable, from an analysis of at least two images relative to two volumetric computerised tomography perpendicular cross-sections of a maxillofacial complex that includes the dental guide on which the support component 1 with the pack of components 2 and 3 is fixed, in such a way that the pack of components 2 and 3 is visible in the two images both in plan view and in side view.

In the example in figure 6, the space references consist of two segments indicated by 22 and 23 which represent the projections of an implant insertion direction on the two faces 20 and 21 and which are manually marked by the dentist on the faces using, for example, a marker pen. The space references 22 and 23 are acquired by means of an acquisition procedure described below.

The procedure for the acquisition of the space references by means of a dental guide made, for example, by copying in acrylic resin the prosthesis of a patient and cutting, by mechanical processing, the space for the insertion of the modular reference system components.

Figures 7 to 9 show a diagnostic dental guide 24 made from radio-transparent acrylic resin and replicating the prosthesis of a patient. The guide 24 comprises a space 25 created by mechanical processing, in which the components of the modular reference system can be positioned. One of the two anchoring portions of the support component 1 is first adapted by the dental technician or the dentist treating the patient, shaping one end 26 of the portion 6 (figure 8) to complement a particular zone 27 of the space 25 in order to allow the subsequent positioning of the pack of components 2 and 3, and then fixed in the zone 27 (figure 9) by means, for example, of a self-polymerizing and radio-transparent acrylic resin.

At this point, a first reference element 2 is mounted on the central portion 4 of the support component and other reference components 2 and spacer components 3 are pack- mounted and alternated on the support component 1, starting from the head reference component 2 until there is a sufficient number of reference components 2 in the space 25, as shown in figure 10.

Figures 7 to 10 show an example of fixing the support component 1 to the guide 24 according to a substantially coronal orientation.

Figure 11 shows another example of fixing the support component 1, wherein the corresponding elements are indicated by the same numbers as in figures 7-10, although the guide shown in the figure is different to the one in figures 7-10, and wherein the support component 1 is fixed to the guide 24 according to a substantially sagittal orientation. To facilitate the fixing of the support component 1, an internal wall 24a is created on the guide 24 next to the space 25.

The subsequent steps of the procedure for space reference acquisition are described below with particular reference to the example shown in figure 11.

The guide 24 fitted with the support component 1 and the relative pack of components 2 and 3, is given to the patient, who is sent to the radiologist to undergo volumetric computerised tomography, specifically so-called Cone Beam Computed Tomography, of the patient's maxillofacial complex with the guide 24 placed in the mouth.

The radiologist processes the computerised tomography to extract a series of sagittal cross-section images and a series of coronal cross-section images, all in 1:1 scale, to give to the dentist. To define sagittal and coronal planes, the cross-section planes of the sagittal images are at right angles to the cross-section planes of the coronal images. The dentist selects at least one image from the series of sagittal cross-section images, for example the image shown in figure 12, and at least one image from the series of coronal cross-section images, for example the image shown in figure 13, both selected images corresponding to centre line cross-sections of the future dental implant. In figure 12, it is possible to see, indicated by 2a, the radiographic outline of the face of the reference components 2, which coincides with the outline of the central portion 4 of the support component 1, and in figure 13 it is possible to see, indicated by 2b, the radiographic outline of the sides of the pack-coupled reference components 2. The fact that the holes 7, 8, 15, and in particular the holes 7, are through holes is a feature that improves visibility of the radiographic outline 2a.

With reference to figure 14, the modular reference system comprises at least two acquisition guides 29, each consisting of a sheet of transparent material, for example a sheet of transparent acetate, showing an outline 30 which reproduces the perimeter of the reference component 2 and, with corresponding circumferences 28, the six holes of the central portion 4 of the support component 1.

With reference to figure 15, a first acquisition guide 29 is positioned on the sagittal reconstruction image in order to superimpose the outline 30 on the radiographic outline 2a. The dentist analyses the image to identify the sagittal projection 31 of the required implant direction and mark it on the acquisition guide 29, for example by drawing a corresponding line with a marker pen. ·

With reference to figure 16, a second acquisition guide 29 is positioned on the coronal reconstruction image in order to match a short side 32 of the outline 30 with the radiographic outline of the side 33 of the head reference component 2, that is to say the one nearest to the support component 1. The dentist analyses the image to identify the coronal projection 34 of the required implant direction and mark it on the acquisition guide 29, for example by drawing a corresponding line with a marker pen.

At this point, with reference to figure 17, the first portion 14 of the transfer component 13 is superimposed on and aligned with the outline 30 of the first acquisition guide 29, matching the holes 15 with the corresponding three circumferences 28 (not visible in figure 17) of the outline 30, and the direction of the sagittal projection 31 is manually copied on the inner face 20 of the portion 14, for example again using a marker pen, thereby obtaining the space reference 22 shown in figure 6. Similarly, the second portion 17 of the transfer component 13 is superimposed on the outline 30 of the second acquisition guide 29, matching the holes 19 with the corresponding three circumferences 28 of the outline 30, and the direction of the coronal projection 34 is manually copied on the inner face 21 of the portion 17, thereby obtaining the space reference 23 shown in figure 6.

According to another embodiment of the invention, not shown, the modular reference system comprises an adapter component, which is the same size as the reference component 2 and has at least three holes which are the same as those of the reference component 2, in such a way that when used it can be aligned with the outline 30 and, at the same time, coupled with the transfer component 13 by means of the pins 16 of the first portion 14 which engage the holes of the adapter component, thereby facilitating the alignment of the first portion 14 with the outline 30.

According to another embodiment of the invention, not shown, the acquisition guides 29 are not used and the adapter component is superimposed directly on the sagittal and coronal reconstruction images, searching for the correct alignment with the radiographic outlines of the reference component 2, in the same way as described above in relation to the use of the guides 29, and the transfer component 13 is positioned on the adapter component in such a way that the dentist can manually copy the sagittal 31 and coronal 34 projection directions directly ^" from the images onto the inner faces 20 and 21 of the portion 14 of the transfer component 13.

According to another embodiment of the invention, not shown, the acquisition guides 29 are perforated in correspondence with at least three of the circumferences 28, in such a way that, when used, the pins 16 of the first portion 14 of the support component 1 can engage the holes of the corresponding circumferences 28 of the acquisition guide 29, thereby facilitating the alignment of the first portion 14 of the transfer component 13 with the outline 30.

According to another embodiment of the invention, not shown, the procedure for the acquisition of space references is a computer-assisted procedure. In particular, in place of the two acquisition guides 29 two adhesive labels are used, and can be attached to the inner faces 20 and 21 of the portions 14 and 17 of the transfer component 13. The outline 30 and the respective space references 22 and 23 are printed on these labels, and the sagittal 31 and coronal 34 projections of the implant direction are identified by means of a computer programme of the type designed to display computerised tomography images or the type used for computer-guided surgery. In particular, the computer programme is configured to recognise the pack of components 2 and 3 in the sagittal and coronal reconstruction images, acquire the sagittal 31 and coronal 34 projections in electronic format on the basis of information entered by the dentist, determine the space references 22 and 23 according to the sagittal 31 and coronal 34 projections identified and print the space references 22 and 23 on the two labels by means of a printer connected to the computer.

The modular reference system described so far, and that is to say comprising the components 1, 2, 3 and 13 and provided with the space references 22 and 23, has in fact transformed the diagnostic guide 24 into a surgical guide for a single tooth imp-lant in simplified guided surgery; it is in fact sufficient for the surgeon to keep the bur aligned with the space references 22 and 23 during cutting.

With reference to figures 18 to 22, the modular reference system comprises additional components which, together with the components 1, 2, 3 and 13, make it possible to perform a single tooth implant in perfected guided surgery. The additional components comprise a guide component 35 (figures 18 and 19) , a slide component 36 (figure 20) which can be slidingly coupled with the guide component 35, a bushing-holder component 37 (figure 21) which can be adjustably coupled with the slide component 36 and a bushing 38 (figure 22), which can be inserted in the bushing-holder component 37 and acts as a guide for the dental implant bur (not shown) . The components 35, 36 and 37 are made from the same material as the spacer component 3. The bushing 38 is made, for example, fro metal or from self- lubricating PEEK (polyether ether ketone) .

With reference to figures 18 and 19, the guide component 35 comprises, on a first face 39, a guide 40 (figure 19) consisting of a rectangular profile groove and, on a second face 41 (figure 18) opposite the first face 39, three pins 42 identical, in size and arrangement, to the pins 9 of the reference component 2 to engage the holes 15 of the first portion 14 of the transfer component 13 and thus allow the guide component 35 to be mounted on the first portion 14 of the transfer component 13 with the guide 40 perpendicular to the second portion 17.

With reference to figure 20, the slide component 36 comprises a base 43, which consists of a substantially rectangular plate appropriately dimensioned to adjustably couple with the guide 40 along it, and a support pin 44, cylindrical in shape and perpendicular to the base 41.

With reference to the figure 21, the bushing-holder component 37 consists of a substantially C-shaped body defining an inner circular housing 45 to accommodate coaxially with interference, and thus retain, the bushing 38, and a side opening 46 that can be engaged revolvingly by the support pin 44 in order to orientate the inner housing 45 so as to align the axis of the bushing 38 in both the directions defined by the space references 22 and 23.

Figure 23 shows the assembly of the components 35, 36,

37 and 38 on the transfer component 13. The guide component

35 is mounted on the first portion 14 with the guide perpendicular to the second portion 17, the slide component

36 is coupled with the guide 40 so that it is positioned with the axis of the support pin 44 perpendicular to the segment which defines the space reference 22 and the bushing-holder component 37 is positioned with the side opening 46 on the support pin 44, once this pin has, if necessary, been cut to facilitate the alignment of the axis of the bushing 38 with the segment defined by the other space reference 23. The components 35, 36, 37 and 38 assembled as described above are fixed together and to the transfer component 13 by means of an appropriate adhesive, for example cyanoacrylate and acrylic resin.

To favour visibility, the segment 22 can be extended with two additional segments, only one of which is visible and is indicated with 22a, drawn on the anchoring portions 6.

The assembly of the components shown in figure 23 transforms the diagnostic guide 24 into a surgical guide for a single tooth implant in perfected guided surgery: in fact, the bur must be used through the bushing and thus stays aligned with the space references 22 and 23 during cutting.

According to another embodiment of the invention shown in figure 24, in which the corresponding elements are indicated by the same numbers as in figure 23, the modular reference system comprises a guide component 47, which is substantially the same as the guide component 35, to be mounted on the second portion 17 of the transfer component 13, another slide component 36 which can be slidingly coupled with the guide component 46 and, in place of the bushing-holder component 37 and the relative bushing 38, two support arms 48, each of which holds a respective source of light 49 and can be revolvingly mounted on the support pin 44 of a respective slide component 36.

The guide component 47 comprises a guide 50, identical to the guide 40 of the other guide component 35, for the adjustable coupling with the base 43 of the relative slide component 36, and two pins 51 identical, in size and arrangement, to two of the three pins 42 of the other guide component 35 for mounting on the portion 17 of the transfer component 13. The guide component 47 is shorter than the guide component 35 so that, when mounted on the portion 17 with the guide 50 perpendicular to the portion 14 and resting laterally against the face 39 of the component 35, it is positioned in the residual space of the portion 17 and is thus flush with the portion 17.

Each source of light 49 is fixed to a first end of the relative support arm 48 and a hole 52 in the other end of the support arm 48 can be engaged by the support pin 44 of the relative slide component 36 thus allowing the support arm 48, and thus the source of light 49, to be rotated with respect to the axis of the support pin 44. Each source of light 49 consists of a simple LED or a laser LED and is provided with a respective lens 53 designed to emit a respective luminous curtain 54, that is to say a substantially flat luminous beam, which extends along a respective plane passing through a longitudinal centre line 48a of the relative support arm 48.

The two support arms 48 and the guide components 35 and 47 are preferably made from a light-transparent material to allow the space references 22 and 23 to be seen during the orientation adjustment of the support arms 48.

In use, each support arm 48 is oriented in order to align the respective centre line 48a with a respective space reference 22, 23 so that the plane of the relative luminous curtain 54 passes through this space reference 22, 23. In this way, by intersecting each other, the two luminous curtains 54 define, in the space between the two portions 14 and 17 of the transfer component 13, a luminous line 55 which substantially coincides with the required implant direction and, on the bone surface in which the hole to house the implant must be made, a luminous cross 56. The luminous line 55 and the luminous cross 56 therefore act as guiding elements for single tooth implant in simplified guided surgery. According to another embodiment of the invention, not shown, the modular reference system comprises, in place of the components 35, 36, 37 and 38, a further component consisting of a prism-shaped element with a square base, presenting a first face that can be coupled with the central portion 4 of the support component 1, that is to say having the same plan dimensions as the central portion 4 of the support component 1 and comprising three pins identical to the pins 9 of the reference component 2 so that it can be coupled with the central portion 4 in the same way as the reference component 2, a second face, parallel to the first face and on which the space reference 22 is marked, and a third face, perpendicular to the second face and on which the other space reference 23 is marked. In this embodiment too, the two space references 22 and 23 can be manually marked using a marker pen or by means of two appropriate printed labels.

According to this embodiment, the prism-shaped element is cut using a parallelometer, or^' a CAD/CAM numerical control cutter, keeping the head aligned with the space references 22 and 23 during cutting, to create the space for the bushing 38.

While the invention described above refers in particular to a very specific embodiment, the invention should not be considered as limited to this embodiment example, its sphere including all the variations, modifications or simplifications that would be evident to a technical expert of the sector, such as for example:

- spacer components with varying thicknesses, that is to say wedge-shaped spacer components, in addition and/or alternative to those with a uniform thickness shown in figure 3, to obtain packs of components 2 and 3 that follow the curved trend of the dental arches if the support component 1 is fixed to the guide 24 according to a substantially coronal orientation;

- the portion 17 of the transfer component 13 has no holes or pins;

- the portion 17 of the transfer component 13 is longer than the other portion 14 so that an orthogonal projection 34 at some distance from the outline 30 can be marked on the transfer component 13;

- the outline 30 is an exact reproduction of the plan outline of the reference component 2, that is to say it reproduces only three holes positioned at the points of a triangle;

- the use of two extension components so that an orthogonal projection 34 at, some distance from the outline 30 can be marked on the transfer component 13, a first extension component consisting of a plate longer than the portion 17 of the transfer component 13 and presenting holes and pins for coupling with the portion 17 and the second extension component consisting of a parallelepiped presenting a first face that can be coupled with the central portion 4 of the support component 1, that is to say having the same plan dimensions as the central portion 4 of the support component 1 and comprising three pins the same as the pins 9 of the reference component 2 so that it can be coupled with the central portion 4, and a second face comprising thee holes positioned in such as way as to be engaged by the pins 42 of the guide component 35 for mounting the latter on the parallelepiped element; and

- the male-female coupling means of the components 1, 2, 3, 13 and 35 comprise holes and pins with different shapes to the cylindrical shape and different arrangements to the points of a triangle.

According to another embodiment, as can be seen in figures 27 and 28, the aiming system according to the invention comprises means that determine a physical restraint in linear movement between the instrument 60, consisting of a dental drill or bur, and the L-shaped reference component 13.

These means comprise a linear guide 61 fixed in an appropriate position and at an appropriate angle on the first portion 14 of the third component 13, and a slide 62 which moves inside the guide 61, and can be fixed to the head of the instrument consisting of a dental drill or bur 60.

In this case, the linear guide 61 acts as a physical restraint between the bur and the support, keeping it perfectly aligned with respect to the preset angle, while the slide 62 holding the instrument slides in the guide.

According to another embodiment, the aiming system according to the invention comprises a laser component 63 fixed to the head of the bur 60 and designed to provide visual indications by means of the laser beam relative to the aiming direction indicated by the third component 13.

In this case, the laser component 63 comprises a cap 64, mounted on the head of the bur 60 and provided with a series of mirrors 64 to divert the laser flow coming from a generator according to a predetermined direction.

The use of the laser component 63 merely involves fitting it on the head of the bur 60, and activating the laser beam so as to project laser beams in the direction of the segments 22 and 23 of the L-shaped reference component 13 which represent the projections of an implant insertion direction.

Claims

CLAIMS A modular reference system to determine, on a diagnostic dental guide (24)., space references to guide a dental implant procedure, the reference system being characterised in that it comprises:

a) a first component (1), which is made from radio- transparent material and can be fixed in a preferred point (27) of the dental guide (24');

b) a plurality of second components (2, 3) divided into reference components (2) made from radio-opaque material, all having the same dimensions, and spacer components (3) made from radio-transparent material, each second component (2, 3) comprising respective means of coupling (7-10) for the pack assembly of the second components (2, 3), alternating reference components (2) with spacer components (3);

c) a portion (4) for coupling of the first component (1) comprising a surface for assembly of the pack of second components;

d) a third component (13) comprising at least one first portion (14), which can be mounted on the coupling portion (4) with coupling means. (15, 16) in place of the pack of second components (2, 3) and on which it is possible to mark the space references (22) that can be obtained from an analysis of a respective volumetric computerised tomography cross-section image of a maxillofacial complex including the dental guide (24) on which the pack of second components (2, 3) is fixed, and a second portion (17), which is perpendicular to and integral with the first portion (14); on the first (14) and second (17) portions of the third component (13) it being possible to mark two respective space references (22, 23) that can be obtained from an analysis of two respective volumetric computerised tomography cross-section images, at right angles to each other, of a maxillofacial complex including the dental guide, it being possible in these images to see the pack of second components (2, 3) according to respective views along two planes at right angles to each other.

2. The reference system according to claim 1, wherein the coupling means (7-10, 15, 16) are the male-female type.

3. The reference system according to claim 2, wherein the coupling means of each second component (2, 3) comprise three holes (7, 8) and three pins (9, 10) , the latter being arranged in order to engage the three holes (8, 7, 15) of the coupling means of another second component (3, 2) .

4 . The reference system according to claim 3, and comprising an acquisition guide (29) consisting of a sheet of transparent material, on which an outline (30) is marked, reproducing the perimeter of the reference component (2) and the outlines of at least three holes identical to the holes (7) of the reference component (2), in such a way that the outline (30) can be aligned with the outline (2a, 2b) of the pack of second components (2, 3) visible in the image in order to acquire the space reference (22) from the image and transfer it to the acquisition guide (29) .

5. The reference system according to any of the foregoing claims, wherein the coupling portion (4) comprises at least three holes (5) and the first portion (14) comprises respective coupling means (15, 16), which comprise three holes (15) designed to be engaged by the three pins (9, 10) of the second component (2, 3) and three pins (16) designed to engage the three holes (5) of the coupling portion (4) for assembly of the first portion (14) on the coupling portion ( 4 ) .

6. The reference system according to claim 5, wherein at least the holes (7) of the reference components (2) are through holes.

7. The reference system according to claim 6, and comprising a fourth component, which comprises a third portion which has the same plan dimensions as the reference component (2) and at least three holes that can be engaged by the three pins (16) of the first portion (14), in such a way that the third portion can be aligned with the outline (2a, 2b) of the pack of second components (2, 3) that can be seen in the image and coupled with the first portion (14) to acquire the space reference (22) from the image and transfer it onto a respective face (20)^' of the first portion ^' (14 ) .

8. The reference system according to any claim from 1 to 7, and comprising additional components (35-38; 35, 36, 48, 49), which can be assembled together and mounted on at least the first portion (14) of the third component (13) in an adjustable way on the basis of the space references (22, 23) in order to define, when used, guide means (38, 54, 55) to guide a bur during the dental implant procedure.

9. The reference system according to claim 11, and comprising a fifth component (35) , which presents, on its first face (39) , a straight guide (40) , and a second face (41) opposite the first face (39) which can be mounted on the first portion (14), with the guide (40) perpendicular to the second portion (17), a sixth component (36), which comprises a base (43) that can be coupled with the guide (40) and a support pin (44) integral with the base (43), and a seventh component (37), which comprises a housing (45) to accommodate and retain a guide bushing (38) for a dental implantology bur and a side opening (46) that can be engaged revolvingly by the support pin (44) in order to orientate the housing (45), and thus the bushing (38), on the basis of the space references (22, 23) .

10. The reference system according to claim 9, wherein the fifth component (35) comprises three pins (42) protruding from the second face (41) to engage the three holes (15) of the first portion (14) of the third component (13) .

11. The reference system according to claim 9, and comprising two fifth components (35, 47), each of which presents, on the first face (39) , a straight guide (40, 50) , and a second face (41) opposite the first face (39) which can be mounted on the first portion (14) or on the second portion (17) with the guide (40, 50) perpendicular to the second portion (17) or, respectively, to the first portion 814), two sixth components (36), each of which comprises a base (43) that can be coupled with the guide (40, 50) of one respective fifth component (35, 47) and a support pin (44) integral with the base (43), and two support arms (48), each of which holds a respective luminous source (49) that can emit a respective luminous curtain (54) that extends along a plane passing through a longitudinal centre line (48a) of the support arm (48) and that can be mounted on the support pin of one respective sixth component (36) in a rotating way with respect to the axis of the support pin (44) in order to align the respective centre line (48a) with one respective space reference (22, 23) .

12. The modular reference system according to claim 1 characterised in that it comprises a linear guide (61) positioned on the first portion (14) of the third component (13), and a slide (62) which moves inside the guide (61), and that can be fixed on the head of the instrument consisting of a drill or bur (60) .

13. The modular reference system according to claim 1 characterised in that the system also comprises a laser component (ZZ) fixed to the head of the bur and designed to provide visual indications by means of the laser beam relative to the aiming direction indicated by the third component (13) .

14. The modular reference system according to claim 13 characterised in that the laser component (63) comprises an element (64) fixed to the head of the bur (60) and provided with a series of mirrors (65) to divert the laser beam coming from a generator according to a predetermined direction.