EP3113713A1

EP3113713A1 - Drilling tool for dental implant surgery, comprising a stepped guide

Info

Publication number: EP3113713A1
Application number: EP15711258.2A
Authority: EP
Inventors: Matthieu SIADOUS
Original assignee: WAM
Current assignee: WAM
Priority date: 2014-03-03
Filing date: 2015-02-27
Publication date: 2017-01-11
Also published as: JP2017506984A; CN106061428A; AU2015226036A1; FR3018040A1; CA2941542A1; FR3018040B1; KR20160130242A; WO2015132513A1; IL247511A0; US20170071696A1

Abstract

Drilling tool (6) for dental implant surgery, this tool (6) comprising: a drilling head (7); a cylindrical mandrel rigidly connected to the head (7) and coaxial therewith, this mandrel being able to be mounted in a pin in order to effect a rotational coupling of the drilling head (7) to this pin; a mesio-distal guide cylinder (18) coaxial with the drilling head (7), this mesio-distal guide cylinder (18) having an external diameter (D2), called the mesio-distal guide diameter, greater than the drilling diameter (D1); a vestibulo-lingual guide cylinder (19) coaxial with the drilling head (7) and situated under the mesio-distal guide cylinder (18), this vestibulo- lingual guide cylinder (19) having an external diameter (D3), called the vestibulo-lingual guide diameter, smaller than the mesio-distal guide diameter (D2).

Description

Drill tool for implant dental surgery, including a step guide

The invention relates to the field of dental surgery, and more specifically to implant surgery (or implantology).

Implant surgery is used to replace a missing tooth or a group of missing teeth with one (or more) implant (s). The act of implant surgery aims to allow the patient to recover an oral appearance and functions of normal chewing and speaking.

Implant surgery is usually performed under local anesthesia; the act consists, in general, to mount an artificial tooth on an implant integrated in the maxillary bone of the patient. The implant is generally in the form of a peg provided with an external thread, which comes directly into a bore previously made in the maxillary bone. Boring the maxillary bone is a delicate operation that requires dexterity on the part of the dentist. This operation usually includes the incision of the gingiva at the implant site right delimited by the teeth (natural or artificial) bordering. Once this incision is made, the surgeon separates the gingival flaps thus made and practices a pilot hole of small diameter (generally of the order of 2 mm) directly in the maxillary bone, by means of a drill mounted on an instrument motorized rotary. You can also operate without a flap, drilling directly through the gum.

Once the pilot hole is completed, the surgeon proceeds to widen it by means of drills of increasing size, until a bore of nominal diameter for the establishment of the implant.

It is essential that the pilot hole is correctly made, because its positioning and orientation depend on the positioning and, respectively, the orientation of the implant and therefore the artificial tooth.

In practice, the drill for making the pilot hole is mounted on a contra-angle itself coupled to a motor. It is understood that, when the bore of the pilot hole is made freehand, the success of this operation is based on the precision of which the surgeon. In particular, it must be attentive to the mesiodistal and vestibulolingual positioning of its tool, and to the orientation of the axis of the drill.

However, the surgeon is not immune to a false movement or spasm of the patient, likely to affect the correct completion of the pilot hole.

In order to avoid this type of incident, solutions have been proposed to guide the drilling operation.

A first technique is to operate using a thermoformed gutter in which is formed a patient's oral impression, this gutter being provided with one or more perforation (s) to the right of (the) site (s) implant (s). Such a gutter, commonly referred to as a surgical guide, however, requires prior operations of taking an impression, making a mold and then manufacturing the gutter. These operations are cumbersome and costly, which explains why most surgeons give up on them in favor of a show of hands, despite the aforementioned risks.

A second technique is to operate using a guide secured to the drill or attached thereto, to achieve a mesiodistal guidance of the drill, the guide being positioned between two existing teeth defining the implant site, or against a single tooth delimiting a total terminal edentation.

Such a guide, described in the international application WO 2012/165093, is in the form of a cylinder having an outer diameter greater than that of the drill on which it is mounted.

While such a guide represents, at first sight, an improvement over the conventional free-hand drilling technique, it does not go without drawbacks.

Indeed, if the mesiodistal positioning of the drill is facilitated by the guide, it is not the same for vestibulolingual positioning. Indeed, the presence of the guide at least partially masks the implant site in the view of the practitioner; at the very least, the guide projects a shadow onto the implant site by placing itself between it and the luminaire (most of which are equipped with the contra-angles), and thus renders difficult a correct appreciation of the vestibulolingual positioning of the forest. A first objective is therefore to propose a solution for improving the positioning of drilling tools in implant surgery.

A second objective is to propose an implant surgery tool providing guidance not only mesiodistal but also vestibulolingual.

For this purpose, it is proposed a drilling tool for implant dental surgery, this tool comprising:

a drilling head, which extends along a main axis, this drilling head having an outer diameter called drilling;

a mandrel secured to the head and coaxial thereto, the mandrel being adapted to be mounted in a spindle for coupling rotatively the drill head with this spindle; a mesiodistal guiding cylinder coaxial with the drill head, said mesiodistal guiding cylinder having an outer diameter, said mesiodistal guiding, greater than the drilling diameter;

a vestibulolingual guide cylinder, coaxial with the drilling head and underlying the mesiodistal guide cylinder, this vestibulolingual guide cylinder having an outer diameter, said vestibulolingual guide, greater than the drilling diameter and less than or equal to the guide diameter mesiodistal.

This tool allows a guidance not only mesiodistal, but also vestibulolingual, for the benefit of the precision (and security) of the intervention.

Various additional features may be provided, alone or in combination:

the tool comprises a one-piece drill bit forming the drill head and the mandrel, and the mesiodistal guide cylinder and the vestibulolingual guide cylinder are attached mounted on the drill;

each cylinder is provided with a central bore for mounting freely rotated on the drill;

the tool comprises a depth stop in the form of a ring integral with the mandrel;

- At least one of the cylinders is integral with the mandrel or the drill head; the mesiodistal guide diameter is between 5 mm and 12 mm;

the buccolingual guide diameter is between 3 mm and 6 mm;

the mesiodistal guide cylinder has a height of between 1 mm and 20 mm;

the vestibulolingual guide cylinder has a height of between 0.5 mm and 20 mm;

at least one of the cylinders is provided with irrigation grooves.

Other objects and advantages of the invention will become apparent in the light of the description of an embodiment, given hereinafter with reference to the accompanying drawings, in which:

Figure 1 is an exploded perspective view showing a drilling system used in implant surgery;

FIG. 2 is an exploded detail view of the tool of FIG. 1;

Figure 3 is a view showing a surgical procedure implementing the kit of Figures 1 and 2;

Figures 4 and 5 are, respectively, mesiodistal and vestibulolingual sectional views illustrating the implementation of the drilling kit in an implant site;

Figures 6 and 7 are similar views respectively to Figures 4 and 5 and illustrating the drilling of a pilot hole in the implant site;

- Figure 8 is a mesiodistal sectional view illustrating a drilling technique of a series of pilot holes.

In Figure 1 is shown a drilling system 1 for implant dental surgery. This tool 1 comprises a surgical instrument 2 equipped with a motor element 3 and a contra-angle 4 fitted on the motor element 3 and incorporating a spindle 5 able to accommodate a range of tools for drilling in a maxillary bone crest (partially visible in Figure 3).

The system 1 further comprises a drilling tool 6.

The drilling tool 6 comprises, firstly, a drilling head 7 (helical in the example illustrated, although it may have a different shape, for example spherical) extending along an axis A main, called drilling. In what follows, height is defined as any distance measured parallel to the axis A.

This drilling head 7 has in the example shown a conical tip 8 and a helical groove 9 (simple, or preferably double) which extends from the tip 8 to a predetermined height.

The drilling head 7 is arranged to allow the production of one or more pilot holes 10 in a maxillary bone crest 11, for the purpose of placing an implant intended to receive a prosthetic tooth.

More specifically, such a pilot hole 10 is provided to be performed in an implant site 12 delimited by at least one existing 13limitrophe tooth (natural or artificial). The implant site 12 may, as in the example illustrated, be delimited on either side by a pair of adjacent teeth 13, 14. In this case, L is the width (measured in a mesiodistal direction) of the implant site 12, and E the thickness thereof, measured in a buccolingual direction on the vertex of the bone crest 11.

It will be observed that when the implant site 12 is dimensioned to accommodate a single prosthetic tooth (replacing a single lost tooth), the pilot hole 10 must be made substantially equidistant from the neighboring teeth 13, 14. On the other hand, when the implant site 12 is sized to accommodate several prosthetic teeth (replacing several lost teeth), the pilot hole 10 must be positioned with reference to the nearest adjacent tooth 13, or with reference to the pilot hole 10 previously drilled, as shown in Figure 8.

The drilling head 7 has an external diameter D1 (overall), called drilling diameter, of between 1.5 and 3 mm. According to a particular embodiment, the diameter D1 is of the order of 2 mm.

The tool 6 comprises, secondly, a mandrel 15 (cylindrical in the example shown), integral with the head 7 and coaxial therewith. This mandrel 15 is dimensioned (and arranged) to be mounted in the spindle 5 of the contra-angle 4 to achieve a rotational coupling of the drill head 7 with the spindle 5.

More precisely, and as can be seen in FIG. 2, the mandrel

15 has, at a distal end (opposite to the head 7), a flat 16 and a peripheral groove 17. The coupling of the mandrel 15 to the pin 5 is made by cooperation of a key and an elastic hook (integrated pin 5) with, respectively, the flat 16 and the groove 17.

The tool 6 comprises, thirdly, a mesiodistal guide cylinder 18, coaxial with the drilling head 7 (and thus the mandrel 15). This mesiodistal guide cylinder 18 has an outer diameter D2, called mesiodistal guidance, greater than the diameter D1 of drilling. The choice of the mesiodistal guide diameter D 2 depends on the width L of the implant site 12. More specifically, the mesiodistal guide diameter D 2 corresponds substantially to the width L when the site 12 is intended to accommodate a single prosthetic tooth, or to the width (measured in the mesiodistal direction) of a prosthetic tooth when the site 12 is intended to accommodate several prosthetic teeth.

In practice, the mesiodistal guide diameter D 2 is preferably between 5 mm and 12 mm.

The mesiodistal guide cylinder 18 extends axially over a height H 2, which is preferably between 1 mm and 20 mm, which makes it possible to cover numerous oral configurations.

The tool 6 comprises, fourthly, a buccolingual guide cylinder 19, coaxial with the drilling head 7 (and therefore with the mandrel 15) and underlying the mesiodistal guide cylinder 18. In other words, the mesiodistal guide cylinder 18 is superimposed on the buccolingual guide cylinder 19.

The vestibulolingual guide cylinder 19 has an external diameter D3, called vestibulolingual guide, which is also greater than the drilling diameter D1 and preferably less than or equal to (for the same tool 6) the mesiodistal guide diameter D2.

The choice of the vestibulolingual guide diameter D3 depends on the thickness E of the implant site 12. More specifically, the buccolingual guide diameter D3 is equal to or substantially equal to the diameter of the final bore intended to accommodate the implant, itself to be chosen equal to or less than the thickness E less a safety margin of twice 2 mm, this margin corresponding to the minimum thickness of bone material that must remain on both sides (in the vestibulolingual direction) of the final bore.

So :

D3 (mm) = E (mm) - 4 In practice, the buccolingual guide diameter D3 is preferably between 3 mm and 6 mm. Furthermore, the buccolingual guide cylinder 19 has an axial height H3 which is preferably between 0.5 mm and 20 mm. This range of heights allows the practitioner to correctly visualize the vestibulolingual positioning of the tool 6, without the axial size (that is to say, the total height) of it is too important. This prevents the patient from having to open his mouth too much during the procedure.

According to an embodiment illustrated in the figures, the tool 6 comprises a single-piece drill 20 forming the drilling head 7 and the mandrel 15, and the mesiodistal guide cylinder 18 and the vestibulolingual guide cylinder 19 are attached by being mounted on the drill 20. The drill 20 is for example made of steel of surgical quality (it is generally a chromium, nickel and molybdenum alloy - let's mention for example the grade X2CrNiMo17-12, commonly used), the head 7 being optionally coated with titanium nitride (TiN). Alternatively, the drill 20 may be made of ceramic or titanium.

The cylinders 18, 19 are also preferably made of surgical steel, although they can be made of any other material compatible with implant dental surgery: titanium, stellite, zirconium oxide (ceramic), silicone, sterilizable polymer, etc. . The cylinders 18, 19 could be secured in translation and / or rotation to the drill 20, for example by means of radial clamping screws, or form with the head 7 and the mandrel 15 a one-piece assembly come machining. In the latter case, a range of tools 6 must be made, including various combinations of diameters D2 and D3 and heights H2 and H3 (for the same diameter D1).

However, according to a preferred embodiment, the cylinders 18, 19 are mounted in free translation and free rotation on the drill. For this purpose, the mesiodistal guide cylinder 18 is provided with a central bore 21 of a diameter corresponding, with the clearance, to the outer diameter D1 of the drill 20. Similarly, the buccolingual guide cylinder 19 is provided with a central bore 22 of a diameter also corresponding, with play, to the outer diameter D1 of the drill 20. By their sliding assembly, the cylinders 18, 19 retain their position relative to the jaw of the patient during the penetration of the head 7 of the drill 20 into the bone ridge 11, to the benefit of precision work.

As can be seen in the figures, and more particularly in FIGS. 2 and 4 to 7, the tool 6 may further comprise an abutment 23 of depth in the form of a ring integral with the mandrel 15 of the drill 20.

Fixing the abutment 23 (in rotation and in translation) on the mandrel

15 of the drill 20 is for example made by means of a radial screw 24 headless (typically hexagonal imprint). In this case it is an adjustable fixing, which makes it possible to modify the depth of drilling.

Care should be taken to maintain between the depth stop 23 and the mesiodistal guide cylinder 18 a distance d corresponding to the drilling depth, in the configuration where the tip 8 is substantially coplanar with a lower end face of the guide cylinder 19 vestibulolingual (as shown in Figures 4 and 5), which corresponds to the beginning of drilling.

This distance d defines the stroke of the drill 20 - that is to say the depth of drilling, the latter being completed when the abutment 23 depth is applied against an upper face 26 of the cylinder

18 mesiodistal guidance (Figures 6 and 7).

The realization of a pilot hole 10 in an implant site 12 defined between two adjacent teeth 13, 14 for the implantation of a single implant is illustrated in FIGS. 3 to 7.

The practitioner starts by choosing the size (diameter D2, height

H2) of its mesiodistal guide cylinder 18 as a function of the width

L of the implant site 12.

The practitioner also chooses the size (diameter D3, height H3) of the vestibulolingual guide cylinder 19 as a function of the thickness E of the bone crest 11. More precisely, as we have seen, the diameter D3 is chosen equal to the thickness E less than 4 millimeters.

The drill 20 is mounted on the contra-angle 4 by being coupled to the spindle 5, then the cylinders 18, 19 are fitted on the drill 20 - first the mesiodistal guide cylinder 18, then the buccolingual guide cylinder 19. The abutment 23 of depth is adjusted according to the criteria defined above, to be distant from the mesiodistal guidance cylinder 18 of the drilling depth.

The practitioner can then perform the drilling operation. The gingiva of the patient may previously have been incised in the mesiodistal direction, and the gingival flaps laterally spaced to clear the implant site 12 on the bone ridge thus exposed (in the figures, it was deliberately, for reasons of clarity, omitted to represent the gingiva). However, it is possible to perform such a flapless surgical operation, that is to say by drilling directly through the gum.

The mesiodistal guide cylinder 18 indexes the tip 8 in the mesiodistal direction. This indexing is achieved by simply inserting the tool 6 in the implant site 12, the adjacent teeth 13, 14 being in contact (or almost) with the cylinder 18. It remains for the practitioner to correctly position the tool 6 in the direction vestibulolinguale, which it can perform judging if it is experienced, or using a depth gauge to verify that the vestibulolingual guide cylinder 19 is at the desired distance (2 mm in common practice) as we have seen) from the edge of the bone ridge.

The drilling can then be carried out by simply pressing the tool 6, the head 7 coming to machine (FIGS. 6 and 7) a bore 10 in the bone crest 11 with a depth equal to the stroke defined by the distance d of the stop 23 depth mesiodistal guide cylinder 18, as preset as previously indicated.

It can be seen that the cylinders 18, 19 simultaneously provide mesiodistal guidance and vestibulolingual guidance. This double guidance benefits the precision of the intervention, and the safety of the patient. The risk of failure of the operation is reduced.

It will be observed that the cylinders 18, 19 also contribute, when they are slidably mounted on the drill 20, to ensure axial guidance thereof, which limits the risk of tilting of the tool 6 during drilling and increases still the precision (and therefore the chances of success) of the intervention.

As can be seen in FIG. 8, the tool 6 that has just been described can make it possible to drill multiple holes in a site 12 implant corresponding to several missing teeth (two in the illustrated example).

A first step consists in producing, by means of the tool 6 previously described, a first bore 10 in the vicinity of a first adjacent tooth 13.

A second step consists in momentarily setting up, in the bore thus produced, a toothed tooth template 27 comprising a tooth shape or a cylinder 28 (of a diameter corresponding to the mesiodistal bulk of the false tooth to be laid ) and a rod 29 of a diameter corresponding to the diameter of the pilot hole 10, or a slightly larger diameter to increase the stability of the template 27. The installation of the template 27 is done simply by introducing the rod 29 in the pilot hole 10.

A third step is to drill a second pilot hole (dashed in Figure 8) in the manner previously described from the template 27 thus laid. When the patient is completely edentulous from the adjacent tooth 13, the mesiodistal guidance is unilateral. In the presence of a second adjacent tooth 14, it provides a bilateral guide.

The tool 6 previously described lends itself particularly, thanks to its ease and accuracy of use, this technique of multiple drilling.

Various variants can be envisaged.

In particular, at least the mesiodistal guide cylinder 18 (and possibly the vestibulolingual guide cylinder 19) could be at least partially made of a transparent or translucent material, so as to transmit the light resulting from an on-board illumination on the counter-light. angle 4, so as to illuminate the implant site 12 and thus facilitate vestibulolingual guidance.

In practice, the mesiodistal guiding cylinder 18 may comprise a tubular steel sleeve to allow its mounting on the drill 20, around which is molded a cylindrical body of plastic (preferably biocompatible) transparent or translucent.

Moreover, it is conceivable to provide that one of the cylinders 18, 19 is made integral (for example by being made of material) of the drilling head 7, the other cylinder being free in rotation and / or in translation. Thus, the mesiodistal guide cylinder 18 could be integral with the head 7, the buccolingual guide cylinder 19 being free.

At least one of the cylinders 18, 19 could also be provided with grooves (helical or straight) irrigation, whose function is to channel a coolant (typically saline) to the implant site 12, to cool the bone and drill 20 which tend to heat up during drilling.

Claims

Implant tool (6) for dental implant surgery, this tool (6) comprising:

- A drilling head (7), which extends along a main axis (A), the drill head (7) having an external diameter (D1) said drilling;

a mandrel (15) integral with the head (7) and coaxial thereto, the mandrel (15) being adapted to be mounted in a spindle (5) for coupling in rotation with the drilling head (7) with this pin (5);

a mesiodistal guide cylinder (18), coaxial with the drilling head (7), said mesiodistal guide cylinder (18) having an outer mesiodistal guide diameter (D2) greater than the drilling diameter (D1);

this tool (6) being characterized in that it comprises a buccolingual guide cylinder (19), coaxial with the drilling head (7) and underlying the mesiodistal guide cylinder (18), this cylinder (19) of vestibulolingual guidance having an outer diameter (D3), said vestibulolingual guide, greater than the diameter (D1) of drilling and less than the diameter (D2) of mesiodistal guidance.

2. Tool (6) according to claim 1, characterized in that it comprises a single-piece drill (20) forming the drilling head (7) and the mandrel (15), and in that the guide cylinder (18) mesiodistal and the buccolingual guide cylinder (19) are reported mounted on the drill (20).

3. Tool (6) according to claim 2, characterized in that each cylinder (18, 19) is provided with a central bore (21, 22) for mounting freely rotatable on the drill (20).

4. Tool (6) according to claim 3, characterized in that it comprises a stop (23) of depth in the form of a ring integral with the mandrel (15).

5. Tool according to claim 1, characterized in that at least one of the cylinders (18, 19) is integral with the mandrel (15) or the head (7) drilling.

6. Tool (6) according to one of the preceding claims, characterized in that the mesiodistal guide diameter (D2) is between 5 mm and 12 mm.

7. Tool (6) according to one of the preceding claims, characterized in that the diameter (D3) of vestibulolingual guide is between 3 mm and 6 mm.

8. Tool (6) according to one of the preceding claims, characterized in that the cylinder (18) mesiodistal guide has a height (H2) between 0.5 mm and 20 mm.

9. Tool (6) according to one of the preceding claims, characterized in that the buccolingual guide cylinder (19) has a height (H3) of between 0.5 mm and 20 mm.

10. Tool (6) according to one of the preceding claims, characterized in that at least one of the cylinders (18, 19) is provided with irrigation grooves.