WO2013170962A1

WO2013170962A1 - Method for guided implantology to insert one or more fixtures in the mandibular and/or maxillary bone and device for said guided implantology

Info

Publication number: WO2013170962A1
Application number: PCT/EP2013/001457
Authority: WO
Inventors: Graziano PIERI
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-05-18
Filing date: 2013-05-16
Publication date: 2013-11-21
Anticipated expiration: 2014-11-18
Also published as: ITTV20130070A1; ITTV20120089A1

Description

Title: Method for guided implantology to insert one or more fixtures in the mandibular and/or maxillary bone and device for said guided implantology.

Description

The present invention concerns a method of guided implantology and a medical surgical device for dental implant, particularly finalised to the fixture assembling method.

For a better comprehension of description are introduced the following phases:

Implant or fixture - is a metal made screw, generally in titanium or zirconium, placed in the mandibular and /or maxillary bone, as a support of prosthetic fixture, and normally reduced into the bone-integration process in a few months, and enhanced from the bones-to-fixture inner contact, without any soft tissue interposition.

Healing screw - is a metallic cylinder screwed on the fixture with the purpose to model the gum on one's shape to keep a proper space in absence of soft tissue, while fitting the prosthetic implant.

Plugging screw - is a metallic cylinder screwed on fixture, according to fixture submerged method.

Transfer - is a metallic cylinder variously grooved set in the fixture when taking the cast, and subsequently integrated into the cast material in order to allow the precise fixture location in the plaster mould.

Fixture - is a metallic cylinder integrated in the dental arch plaster mould with the purpose to replicate the same position installed in the patient's mouth. The fixture is set before the plaster mould realisation.

Stump - is a tapered or cylindrical metallic element, screwed on the fixture by means of a proper occlusive screw, coupled with the dental prosthesis; generally the stump axis is not corresponding to fixture and therefore it is necessary to control its position for a correct prosthesis orientation.

Geometrical coupling - usually is an hexagonal section element, partially realised on the fixture and on the stump, to direct correctly stump to fixture position.

Occlusive screw - is the screw for fixture elements, it particularly fixes the transfer, stump, etc.

Radiological dima - is a shaped plate into the patient's mouth, over the gums, replicating its geometry, for a CAT determination, since soft tissues (gums) are transparent to X-rays. Individual surgical dima - is a dima produced in laboratory in the model of the patient's mouth, incorporating the bushings designed to drive the fixture drilling in their seats and mounting the said in their seats.

Prosthesis - is the element that replaces the lack of teeth and mounted on the stumps. The dental prosthesis process provides the fixture fitting in the mandible bone site, as a mechanical backing to ensure the implant firmness, and later, if properly placed, will guarantee the prosthesis rehabilitation. The actual installation techniques are of several methods and herewith described, being some contemporary but not extensive methods. They are exemplified to show the actually faced problems. The main fixture placement typology are included in two orders:

- anatomical guideless system

- guided implant planning system.

The first method leads back to a traditional and pioneering surgical system, by using simple intraoral X-ray images and the direct implanted area operating appraisal, under volume and intensity indications. Method quality lays on manual ability, dentistry acknowledge and operator competence. The system requires many sessions, through several months intervals, thus ensuring both fixture bone-integration and prosthesis realisation.

The method is affected by the critical and uneasy accuracy of fixture inclination, according to chewing strain, and strengths may occur with orthogonal implant components, producing stability problems.

To avoid the disadvantage, the guided procedure provides the determination of the correct position, drilling inclination and depth, working in the laboratory on a model of bone of the patient's mouth, to insert the fixture in the holes model, to place in the holes the bushings which will be inserted in an individual surgical dima, realised on the patient's mouth model.

The individual surgical dima, transferred in the patient's mouth, will guide the drilling in the fixture seats in the correct position, inclination and depth, using the incorporated bushing to drive the mill.

The fixtures will be inserted according with this method in the correct position, inclination and depth. Said fixtures inclination are suitable to optimise the implant mechanical strength, generally different between them, for an appropriate prosthesis mounting. As a consequence, once the fixtures are realised by means of the individual surgical guide, it is necessary to have the dental print, particularly of the fixture geometrical couplings, being said print used for stumps realisation where the prosthesis will be implanted. The stumps are therefore designed to be mounted on the fixture using the geometrical coupling, their axis oriented in the correct way for the next geometrical coupling orientation, that is the fixture rotation on its own axis.

Due to the casual position, it is necessary, while realising the prosthesis, the data transfer by the said print. As a consequence, the patient incurs in several phases, to following interventions:

- geometrical dental arch screening;

- survey of fixture standing out on the bony crest and replication element mounting;

- survey of fixture print;

- stumps and prosthesis mounting;

Purpose of the invention is to overcome said disadvantages offering a method and a device, to realise said method, respectively corresponding to claims 1 and 3.

The method is characterized in the fact that it comprises the following phases:

- determination of the correct position, inclination, depth and orientation of rotation about its own axis of said fixtures, working in the laboratory on a model of bone of the patient's mouth, said position, inclination, insertion depth and orientation being determined simultaneously with the definition of the geometry of stumps necessary for mounting the prosthesis;

- realization of appropriate means to insert said fixture in the patient's mouth, replicating the same position, insertion depth, inclination and orientation determined in the laboratory, so that said stumps, mounted on the respective fixture, take the correct position for mounting the prosthesis.

The device according to the invention comprises an equipment able to insert the fixture by drilling the bone in its seat, simultaneously controlling the insertion depth and orientation of fixture. Said device comprises an individual surgical dima suitable to be fixed in the patient's mouth replicating the same position that said individual surgical dima had in the patient's mouth, said individual surgical dima incorporating one or more bushings designed to drive a mill to drill one or more seats for said fixtures and one or more mounters suitable to insert said one or more fixtures in their seats, mounting of said one or more fixtures taking place by screwing in their seats using said one or more bushings incorporated in the said individual surgical dima to guide said one or more mounters, and is characterized by the fact that said one or more mounters are externally threaded and engage corresponding threads created inside said one or more bushings, means being provided suitable to simultaneously control insertion depth and orientation of said one or more fixtures.

According to the described performance, fixture and stump are a monophasic system, fixture and stump are therefore two different objects whose mutual position is determinated by the geometrical coupling.

According to a different performance, fixture and stump are realised in one part only (monophasic system). In this case, the invented device allow to insert the fixture be screwing it in its seat, simultaneously obtaining the stump mounting in the correct position for the next prosthesis insertion.

The invention main advantage is characterized by the work reduction on patient's mouth, being the operation transferred largely in the laboratory, from the patient's mouth. Once that all elements are prepared, it is only requested one session to implant six or eight fixtures of a total dental arch (mandible or maxillary bone) for the next prosthesis fixing.

A further advantage consists in the fact that all operations to perform directly in the mouth are precisely driven by the device according to invention, so to eliminate virtually any possibility of error incurring.

The invention herewith described according to a preferred performance, is referred to a fixture mounting on a mandibular bone, and referred to enclosed figures, whereas:

- figures from 1 to 10 indicate device according to the invention in the several insertion phases of a fixture in diphasic coupling with external hexagon; figures from 11 to 13 indicate device according to the invention in the several insertion phases of a fixture in diphasic coupling with internal hexagon;

figures from 14 to 16 indicate device according to the invention in the several insertion phases of a monophasic fixture; figure 17 is a general drawing of the invention;

figure 18 shows an alternative device for fixture mounting;

With reference to the enclosed figures , in 1 is indicated a threaded mounter, provided with a cylindrical body la, externally threaded, to be screwed in a bushing 29, internally threaded. The threaded mounter 1 ends with a flange lb and an hexagonal head lc. Internally to the threaded mounter 1 is drawn a cylindrical cavity Id, carrying an hexagonal section in the lower site le.

Reference 3 shows a fixture with a better known external diphasic coupling, made of a threaded cylindrical body ending with an upper hexagonal head 3 a, suitable to be inserted in lower side le of mounter 1 cavity Id. Internally to the hexagonal head 3a of fixture 3 a threaded hole is suitable to engage the fixture 3 to the threaded mounter 1 by means of a proper screw 4.

Said hexagonal head 3a of fixture 3 and the hexagonal section cavity le are forming a geometrical coupling to determine precisely the fixture position 3 with the threaded mounter 1.

In the figures, the fixture and the stump axis seem they have to match. Actually this is not occurring since, if it was so, it would not be necessary to control the fixture rotation.

Nevertheless the inclination difference between the fixture axis and the stump axis is quite small, and omitted in the figure to avoid drawing complications.

In figure 2 are shown the mandibular bone 6, the gum 7 and the threaded bushing inserted in an individual surgical dima 5, previously realised in laboratory on a model of patient's mouth. Said individual surgical dima 5, transferred in the patient's mouth will be used to mill their seats 9 of fixture 3 for the following fixture 3 mounting in their own seats.

In figures 3 a and 3 b is shown the bone 6 drilling, to realise one of said seats 9 of fixture 3 (more evident in the following figures), realised by a well known type of mill 10 or 11. The mill 10, 11 carries a smooth cylindrical body 10a, or threaded 11a that is precisely inserted in the threaded driving bushing 2. The drilling depth is determined by a flange 10b, 1 lb of the mill 10, 11 served against the bushing 2.

The bushing 2 both allows the passage of the smooth cylindrical body 10a of the mill 10 and the use of a mill 11 with threaded drive body 1 la to be screwed in the bushing 2. To mount the fixture 3, the threaded mounter 1, where the fixture 3 is mounted, is screwed in the bushing 2. Screwing the threaded mounter 1 to the threaded bushing 2 (figure 4), the fixture 3 is screwed in the seat 9 drawn the bone 6, said fixture 3 being fixed to the mounter 1 with the screw 4. The threaded mounter 1 is screwed in the bushing 2 until its flange lb reaches the bushing 2. When the flange lb of mounter 1 is in contact with the threaded bushing 2 (figure 5), the fixture 3, compared with the individual surgical dima and the patient's mouth, has the same position, inclination, depth and orientation of the laboratory model. The result is therefore to determine the fixture 3 depth, its inclination and orientation of geometrical coupling, determined by the hexagonal head 3 a of the fixture 3.

The operation follows by separating the mounter 1 from fixture 3 (figure 6), by unscrewing the occlusive screw 4 and the following mounter 1 removal (figure 7) and of individual surgical dima 5 (figure 8). In the fixture 3 is the mounted the stump 12 (figures 9 and 10), fixed with the same screw 4. Internally to the stump 12 is drawn a cylindrical cavity 12a having an hexagonal section at lower side 12b, suitable to be coupled the hexagonal head 3a of fixture 3, to determinate precisely the position on the stump 12 referred to the fixture 3. The geometrical coupling of the fixture 3 with the stump 2 is the same both in the model and in the patient's mouth since the threaded bushing 2, is the same and the threaded mounter 1 is identical to its laboratory replication.

On the stump 12 is finally mounted the prosthesis 13 (figure 10).

The figures from 1 to 10 it is shown the invention referred to a fixture with diphasic coupling, or with hexagonal head 3a of fixture 3 stretching out from the same fixture. In the figure 11 is shown the invention referred to a fixture mounting with internal diphasic coupling, or with hexagonal coupling 21a of the fixture 21 stretching inside the same fixture 21. In this case the mounter 22 joins the fixture in internal diphasic coupling 21 by means of a lower hexagonal element 22e, and said mounter 22 has like the mounter 1 , a threaded body 22a, a flange 22b, an hexagonal head 22c and a cylindrical cavity 22d. Also in this case the mounter 22 is fixed on the fixture 2 by means of an occlusive screw 4.

The figure 12 shows the fixture with internal diphasic coupling 219, mounted in the mandibular bone 6 and coupled with the respective stump 22, while in the following figure 13 is shown the prosthesis 13 mounted on the stump 23. The figure 14 shows a monophasic fixture 24, where fixture and stump are made in one piece only. Also in this case is applied the same mounting method, and the difference stands to determination of stump-fixture 24 orientation, instead of the geometrical fixture-stump coupling. The threaded mounter 25, is shaped to be coupled with the part of stump of monophasic fixture 24 and inserted in the same monophasic fixture by means of a occlusive screw 4.

The figure 15 shows the monophasic fixture 24, mounted in the mandibular bone 6, where (figure 16) it is mounted the prosthesis 13.

The figure 17 shows the surgical dima 5 positioned in the gum 7. Internally to said surgical dima are drowned two threaded bushings 2. The figure shows the mounting of a couple of fixtures 3 in the bone 6 where have been preventively realised proper seats 9. In the group composed by the threaded mounter 1 and the fixture 3, closed by the screw 4, is inserted by screwing a threaded bushing 2, up to complete insertion of fixture 3. The threaded mounter 1 is lately released removing the screw 4 and remains in the threaded bushing 2. By removing the individual surgical dima 5 are recovered the threaded mounters 1.

According to the favourite performance, shown in the figures 18 (a, b, c), the orientation control of diphasic fixture 3, 21 or of the monophasic fixture 24 is performed shaping the mounter flange and the top edge of said bushing. In this way the top flange 26a of mounter 26 is equipped with a tooth 26b that, following the threaded bushings screwing 27 is abutting against a corresponding tooth 27a on the top edge of said bushing 27.

The figure 18a shows the mounter 26, coupled with the respective fixture, about being screwed in the bushing 27, inserted in the surgical dima 5 (not shown in the figure 18). In the figure 18b, the mounter is almost completely screwed in the bushing 27; as clearly shown in the magnified detail, a threading is missing to complete the screwing operation.

In the figure 18c the screwing is complete and the mounter, and fixture, rotation stops when the tooth 26b of the flange 26a of mounter 26 is abutting against the tooth 27a on the top edge of the threaded bushing 27.

To this point, for a better comprehension of invention use, are specified the following operational phases.

A part of proceed keeps the same formality normally used in the realisation of mandible and gum model that foresee the following phases:

- development at dentist' surgery of patient's dental print for occlusive determination;

plaster model realisation of patient's mount by means of a radiological dima including the occlusive determination;

- high resolution CAT using said radiological dima; CAT result will issue the information for the model realisation;

- stereo-lithographic manufacturing process of mandible or maxillary bone, if necessary, including hard tissue (bone) and soft tissue (gum), isolating sites like mandible nerve sites, etc.;

- technician's laboratory intake of information related to type and number of implants, prosthesis type, etc., along with the stereo-lithographic model, plaster model and radiological dima with occlusive determination;

- model assembling using an equipment to simulate mouth movement during mastication (articulation frame), and realisation of missing teeth with wax or other modelling material (diagnostic waxing);

- specification of drilling direction points by means of mills;

- drilling on stereo-lithographic model;

from this point, the invention requests to follow the installation phases, herewith enclosed, (for a simple reference, in this description will be indicated only the relation of fixture with external diphasic coupling), as shown in figures from 1 to 10, furthermore it is indifferently referred to mandibular bone 6 and to said bone model, which is always identified with number 6, since the geometry is identical;

- screwing of threaded bushings 2 on replication tails of threaded mounters 1 until the same bushings 2 are abutting against the flanges lb of threaded mounters replication 1 , mounting of fixture 3 on mounters replication 1 by means of screws 4 and following positioning of fixtures 3 in the drills realised on bone model 6;

- resin process of individual surgical dima 5, having the threaded bushings 2, and taking care to wax also the threaded mounters 1 not included in the related threaded bushing 2, and undercuts elimination, to enable the individual surgical dima 5 extraction from the model;

- removal of individual surgical dima 5 from model, unscrewing the occlusive fixing screws 4 from threaded mounters replication 1 to the related fixtures 13; - prosthetic stump mounting 12 or other devices related to teeth morphology, on fixture 3 remained in the model 6, to enable prosthesis production;

- technician's laboratory send the individual surgery dima 5, the stumps 12 and the prosthesis 13 to the dentist;

- positioning of individual surgical dima 5 in the patient's mouth and its steady fixing to keep a proper precision while transferring the fixture 3 position realised in laboratory and related to information of inclination, depth and fixture 3 diameter, and orientation of fixture-stump coupling (figure 2);

gum cutting 7, matching with the fixture 3 site using for example circular bistoury driven from bushings, and removal of top from the gum or with traditional surgical access;

- realisation of seats 9 in the bone 6 with a mill 10, 11 having a smooth drive body 10a, or threaded 11a, which is inserted in the bushings 2, so that the seats 9 have the correct depth (figures 3a, 3b);

- positioning of fixture 3 in its seats 9 screwing the threaded mounters 1 suitable to insert the fixtures 3 by means of screws 4 in their threaded bushing 2, screwing of threaded mounters 1 until the flanges lb of said mounters 1 is abutting against said threaded bushing 2 (figures 4, 5);

- disassembling of threaded mounters 1 removing the fixing screws 4 and disassembling of individual surgical dima 5, removed together with the bushings 2 and the mounters 1, leaving the fixtures 3 in the bone site (figures 6, 7);

- stumps assembling 12 following the orientation of geometrical coupling fixture- stump figures 8 and 9);

- prosthesis fixing 13 on the stumps 12 (figure 10).

Since the threaded bushings 2 are incorporated in the individual surgical dima 5 in the same position and orientation had in the laboratory model, the fixture mounting 3 according to the described method, will position the fixture 3 exactly as the laboratory model, including the orientation. The next stump mounting 12 on the fixture 3, using the geometrical coupling, will allow the correct inclination of all axis of stumps 12 for the following prosthesis mounting 13.

The components are medical stainless steel made or other material suitable both for the monophasic and diphasic system. Their realisation are achieved by lathe and threading machines on cylindrical components. The performance needs a high working accuracy to ensure that coupling between the threaded bushing (female thread) and the threaded mounter is of suitable precision with high sameness of component dimensions, to ensure the correct fixture mounting.

The invention has been described for illustrative purpose and not limitative, according a favourite performance method. The technician, expert in this process, will find several performing modes, all in field of the enclosed protection of claims.

Claims

1. Device for guided implantology to insert one or more fixtures (3, 21, 24) in the mandibular and/or maxillary bone (6), by controlling position, inclination, insertion depth and orientation of rotation about its own axis, which includes an individual surgical dima (5) suitable to be fixed in the patient's mouth, replicating the position that said individual surgical dima (5) had in the model of the patient's mouth, said individual surgical dima (5) incorporating one or more bushings (2, 27) designed to drive a mill (10, 11) to drilling one or more seats (9) for said one or more fixtures (3, 21, 24) and one or more mounters (1, 22, 25, 25) suitable to insert said one or more fixtures (3, 21, 24) in their seats (9), mounting of said one or more fixtures (3, 21, 24) taking place by screwing in their seats (9) using said one or more bushings (2, 27) incorporated in the said individual surgical dima (5) to guide said one or more mounters (1, 22, 25, 26), characterized in that said one or more mounters (1, 22, 25, 26) are externally threaded and engage corresponding threads created inside said one or more bushings (2, 27), means being provided suitable to simultaneously control insertion depth and orientation of said one or more fixtures (3, 21, 24).

2. Device for guided implantology, according to claim 1, characterized in that said means, suitable to simultaneously control insertion depth and orientation of said one or more fixtures (3, 21, 24), include a flange (lb, 22b, 25b), of said mounter (1, 22, 25) designed to stop the screwing of said threaded mounter (1, 22, 25) into said threaded bushing (2), abutting against the top edge of said threaded bushing (2), when the orientation taken by said one or more fixtures (3, 21, 24) coincides with the orientation predetermined in the laboratory.

3. Device for guided implantology, according to claim 1, characterized in that said means, suitable to simultaneously control insertion depth and orientation of said one or more fixtures (3, 21, 24), include a flange (26a) of said mounter (26), said flange (26a) being equipped with a tooth (26b) to stop screwing by said mounter (26) in sais bushing (27), abutting against a corresponding tooth (27a) on the top edge of said bushing (27).

4.Method for guided implantology to insert one or more fixtures (3, 21, 24) in the mandibular and/or maxillary bone, characterized in that it comprise the following phases:

- determination of the correct position, inclination, insertion depth and orientation of rotation about its own axis of said fixtures (3, 21, 24), working in the laboratory on a model of bone (6) of the patient's mouth, said position, inclination, insertion depth and orientation being determined simultaneously with the definition of the geometry of stumps (12, 23) necessary for mounting the prosthesis (13);

- realization of appropriate means to insert said fixture (3, 21, 24) in the patient's mouth, replicating the same position, insertion depth, inclination and orientation determined in the laboratory, so that said stumps (12, 23), mounted on the respective fixture (3, 21, 24), take the correct position for mounting the prosthesis (13).

5. Method for guided implantology to insert one or more fixtures (3, 21, 24) in the mandibular and/or maxillary bone, according to claim 4, characterized in that said means, suitable to insert said fixtures (3, 21, 24) in the patient's mouth, replicating the same position, insertion depth, inclination and orientation determined in the laboratory, are according to one or more of the claims from 1 to 3.