Patent Description:
A dental turbine, or a dental contra-angle handpiece, is a dental milling instrument comprising a working head with a bur rotating at a speed of <NUM>,<NUM> to <NUM>,<NUM> revolutions per minute for milling hard tissues of the teeth, such as enamel or prosthetic material. The dental laser is another type of dental instrument which in this case uses a laser tip, instead of a bur, to ablate the aforementioned hard tissues.

Conventional dental turbines, contra-angle handpieces and lasers incorporate an air and water irrigation system to cool the heat produced by the friction of the drill or laser on the teeth. This cooling fluid is necessary to prevent the pulp of the tooth from overheating, and also helps to release the milled material or material resulting from the ablation, to improve visibility of the working area. However, the effect of the air jet and the cooling water on dental tissues produces suspensions of tiny particles of solids and liquids (aerosols) that are a source of disease transmission for the patient and the operator. In the case of dental lasers, in addition to the aerosol effect of the cooling fluid, there is also the effect that the laser energy produces on the water in the tissues, creating micro-explosions that project energetic particle plumes resulting from the ablation caused by the laser mixed with bacteria, viruses and multiple blood by-products.

It is well known that fluid deflections and aerosols generated during daily dental work pose a risk to both the health of the operator and patients, as they are a source of transmission of diseases and pathogens to which professionals are continuously exposed. In particular, it must be taken into account that aerosols can remain in suspension in the dental surgery environment for a time of more than four hours, which significantly increases the risk of disease transmission. This was clearly demonstrated during the SARS-CoV-<NUM> pandemic crisis.

Dental turbines are known which incorporate in the turbine casing itself suction means for sucking into the oral cavity mainly cooling liquid and milling debris produced by the effect of the turbine's drill. Patent <CIT> discloses a dental turbine of this type in which the casing body of the turbine itself defines a first aerosol suction cavity and a second cavity for accommodating supply ducts for pressurised air and cooling fluid. Dental instruments such as those described in the aforementioned patent have the drawback that suction of fluid deflections and aerosols is limited to the vicinity of the area of action of the drill or laser, so that a significant percentage of ejections cannot be suctioned and are released into the environment of the box. In addition, the fluid suction flow rate provided by these dental instruments is also very poor, and clearly insufficient to ensure effective absorption of the fluid deflections and aerosols that are generated inside the patient's oral cavity.

Dental suction devices, such as the one described in <CIT> or <CIT>, are known, which can be removably attached to a tartrectomy device such as an ultrasonic scaler, which is used to remove tartar by means of ultrasonic vibrations. These devices also use a water irrigation system, in this case without air, the water being nebulised by the back-and-forth movement of the ultrasonic tip in a direction perpendicular to the longitudinal axis of the ultrasonic tip. Dental suction devices such as the one described in the aforementioned patent include a suction body which covers the ultrasonic tip by way of a screen to aspirate the liquid nebulised by the vibration. However, these devices are not suitable for absorbing the fluid deflections produced by the effect of a drill or laser but are only useful for absorbing the water mist generated by the vibration of the ultrasonic tip.

The aim of the present invention is to solve the aforementioned drawbacks by providing a dental suction device with the advantages that will be described below.

In accordance with this objective, according to a first aspect, the present invention provides a dental suction device suitable to be coupled to a dental instrument provided with a drill or laser tip and injection means for injecting under pressure a jet of cooling fluid comprising a mixture of air and water. This device comprises suction means for sucking into the oral cavity fluid deflections and aerosols produced by the effect of the drill or laser of the dental instrument and attaching means for removably attaching the said device to said dental instrument.

The device is characterised in that the suction means comprises a tubular fluid suction body forming a first outer cavity or outer housing intended to receive a dental instrument working head, wherein a distal tubular portion of the tubular suction body extends, for example radially, so as to at least partially surround the perimeter of the first outer cavity or outer housing in which the dental instrument working head is housed, and wherein a wall of said distal tubular body portion incorporates at least one suction orifice arranged so as to determine a perimeter area of fluid suction in an upward direction that at least partially surrounds the first outer cavity or outer housing for receiving the working head, said distal tubular body portion being sized so that it can be introduced inside the patient's mouth while the working head of the dental instrument is operative.

The claimed device has the advantage of having a tubular suction body whose outer walls form a first outer cavity or outer housing designed to receive the head that supports the dental instrument's bur or laser, so that the head, instead of being housed inside the tubular suction body, is located on the outside surrounded by the suction body itself, which greatly facilitates the handling of the device, constituting an accessory complement to the turbine, dental contra-angle handpiece or dental laser. In addition, the distal tubular portion of the suction body extends radially so that it surrounds the cavity or housing where the head is housed, and forms a wall incorporating one or more peripheral upward suction orifices. The position of the suction orifices is adapted to the trajectory of fluid deflections and ejections of liquids and solids generated inside the oral cavity by the effect of the drill or laser.

Unlike the devices of the prior art, the device of the present invention allows fluid deflections and aerosols to be absorbed almost entirely and much more efficiently inside the circumferential area where they occur. In fact, the dental turbines with suction existing in the state of the art incorporate narrow fluid suction channels inside their casing that generate fluid turbulences that cause a markedly deficient suction. In the device of the present invention, the enlarged perimeter area of upward suction provided on the wall of the distal portion of the tubular body is arranged in such a way that it can approach the perimeter of action of the drill or laser to take advantage of the suction strength, without producing undesirable turbulences, while also covering practically the whole area where the deflections are generated. In particular, in the claimed device, the fluid deflections generated by the water and air spray jet when bouncing are effectively sucked away due to the proximity that the suction orifices can acquire to the place where this happens, and due to the barrier effect generated by the enlarged peripheral suction area provided in the distal portion of the tubular body.

The claimed device generates a circumferential suction effect designed so that, in proximity to working surfaces, the flow of spray (a mixture of air and water) injected is transformed by the effect of the suction into a stable toroidal vortex at the centre of which is the bur or laser tip. Thanks to the stability provided by the fluid movement within the toroidal vortex, the aerosol produced is very efficiently confined. In particular, the at least one suction orifice is provided in the wall of the distal tubular portion in such a way as to determine a peripheral area of fluid suction in an upward direction substantially parallel to the axis of the drill or laser tip of the dental instrument. In fact, the upward suction is in the opposite direction to the downward jet of spray (air/water mixture) that accompanies the drill or laser tip of the dental instrument.

Preferably, the suction means of the device provides an air suction flow rate greater than the flow rate of water and air injected by the turbine. Thus, when the device is in operation, the laminar flow of incoming outside air creates a reverse curtain effect that helps to confine the turbulence of fluid deflections within the perimeter surrounding the outside cavity.

Surprisingly, the configuration of the distal portion of the tubular body that extends radially so that it surrounds the first outer cavity or outer housing where the working head of the dental instrument is housed allows high air suction flow rates to be applied, without affecting the cooling effect of the water/air mixture injected on the drilled or ablated tissues.

According to one embodiment, the wall of the distal portion of the tubular body incorporating the at least one fluid suction orifice extends radially outwards from the first outer cavity or outer housing for receiving the working head of the dental instrument with a width determined by a distance "d". This distance "d" is sized so as to absorb fluid deflections that form an angle "α" between <NUM>° and <NUM>° with the axis of the drill or laser of the dental instrument head.

The device of the present invention has the advantage that the distal portion of the tubular body extends radially so that the tubular body itself surrounds the cavity or receiving housing of the working head, incorporating one or more orifices that determine a perimeter area of upward suction suitable for absorbing violent deflections of fluid which, in devices of the prior art, escape the area of action of the turbine or laser suction system.

Advantageously, the wall of the distal portion of the tubular body incorporating at least one perimeter fluid suction orifice extends radially outward from the outer receiving cavity or housing of the working head a distance "d" equal to or greater than <NUM>, preferably a distance "d" between <NUM> and <NUM>, for example, a distance between <NUM> and <NUM>.

According to one embodiment, the tubular body further forms a second outer cavity or housing intended to receive a dental instrument working head support neck or handle, the distal portion of the tubular body extending radially on both sides of said second outer cavity for receiving the working head support neck, and the wall of the distal portion of the tubular body also incorporating one or more suction orifices on both sides of the second outer cavity for receiving the support handle.

This embodiment has the advantage that it allows the upward suction perimeter area to extend towards the rear of the distal portion of the tubular body, thus preventing aerosol leakage through the rear of the instrument while the instrument is in operation.

In particular, advantageously, the suction body is a tubular body comprising;.

Preferably, the distal tubular portion extends on both sides of the second outer housing for receiving the handle, in correspondence with the neck of the handle, so that it at least partially surrounds the perimeter of both the outer cavities or outer housings for receiving the working head and the support neck of the working head. The wall of the distal tubular portion, on both sides of the second outer housing, also incorporates one or more suction orifices.

The proximal portion of the tubular body can be attached or coupled to the handle of a conventional dental turbine or laser by means of a clamp or by means of a clipping or press-fit system. For example, the clipping attachment system comprises one or more projections of the proximal portion of the tubular body that fit into the turbine or laser support handle to secure the attachment of the device to the dental instrument.

Advantageously, the peripheral area of upward fluid suction determined by one or more fluid suction orifices increases or decreases towards the more distal end of the tubular body of the device.

According to one embodiment, the distal portion of the tubular body extends radially forming a bifurcation of tubular bodies creating an intermediate hollow space intended to define the first outer cavity or outer housing for receiving the working head of the dental instrument, said outer cavity or housing including an access hole for accessing the button on the upper part of the working head and allowing a change of turbine or contra-angle drill, without the need to uncouple the head of the device from the dental instrument. In addition, this access hole allows heads of different heights to be accommodated without altering the fit of the dental instrument in the device.

This bifurcation defines two tubular bodies in the form of branches of the suction tubular body that extend radially such that each one surrounds a portion of the perimeter of the first outer cavity or outer housing in which the dental drill or laser support head is housed. Each of these tubular bodies or branches includes a wall incorporating one or more upward perimeter suction orifices whose position adapts to the trajectory of the fluid deflections and ejections of liquids and solids generated inside the oral cavity by the effect of the turbine or laser.

According to one embodiment, the distal portion of the tubular body incorporates a plurality of upward fluid suction orifices arranged to extend peripherally around both the outer receiving cavities of the working head and the support neck of said working head. These orifices may be configured, for example, as one or more through slots provided in the bottom wall of the distal portion of the tubular body. Advantageously, the cross-section of these through orifices or slots determines a fluid passage in the bottom wall of the distal portion of the tubular body equal to or greater than <NUM>, and a perimeter area of upward suction approaching or exceeding <NUM><NUM>.

According to one embodiment, a cross-section of these through orifices or slots, in particular, the cross-section of the through orifices or slots extending at least partially on both sides of the perimeter of the second outer housing that receives the neck of the handle, includes walls of the orifices oriented vertically in a radial direction, towards the area where deflections would tend to escape. The orientation of these walls, together with the extension of the through slots towards the second outer housing, has been found to help maintain the toroidal vortex stable with its centre at the laser tip or drill, also confining the escape of aerosol in this area.

Again advantageously, the tubular body lumen has a decreasing area from the proximal portion of the tubular body towards the distal portion of the tubular body. In this way, the suction strength remains stable. Additionally, the dimensions of the distal tubular body portion are small and suitable for convenient handling of the device inside the oral cavity.

Preferably, the dental suction device comprises a vacuum source and means for connecting said vacuum source to the suction tubular body. This source is suitable for providing standard vacuum values in dental suction systems, for example, of about <NUM> millibars.

According to a second aspect, the present invention provides a dental suction device and instrument assembly comprising a device as claimed, and a dental turbine or dental contra-angle handpiece provided with injection means for injecting under pressure a jet of cooling fluid and/or spray (air/water mixture) capable of producing aerosols comprising milled particles in suspension from tooth tissues.

According to a third aspect, the present invention provides a dental suction device and dental instrument assembly comprising a device as claimed, and a dental laser provided with injection means for injecting under pressure a jet of cooling fluid and/or spray (mixture of air and water) capable of producing aerosols comprising plumes of particles resulting from the ablation effect produced by the laser tip on the tooth tissues.

Advantageously, the turbine, dental contra-angle handpiece or dental laser used with the claimed device are conventional commercially available instruments, and the first cavity or outer housing formed by the tubular body of the device is adapted to receive a working head of said turbine or dental laser.

In the present invention, a dental turbine or dental contra-angle handpiece refers to an instrument having a working head comprising a rotor that drives a drill. The rotor is preferably driven by air compression, in the case of the turbine, or by an electric micromotor, in the case of the dental contra-angle handpiece, at a speed ranging in the case of the turbine between <NUM>,<NUM> and <NUM>,<NUM> revolutions per minute and, in the case of the contra-angle handpiece, between <NUM>,<NUM> and <NUM>,<NUM> revolutions per minute. Both the turbine and the dental contra-angle handpiece include injecting means for injecting a jet of pressurised water and air to compensate for the heat produced by the friction of the drill.

The term dental laser refers to an instrument with a working head including a laser tip, preferably an Erbium or Erbium-Chromium laser capable of ablating hard tissues. The dental laser also includes injecting means for injecting a jet of water and pressurised air to compensate for the heat produced by the ablation of the tissue.

To facilitate the description of what has been described above, drawings are appended which represent, schematically and only by way of non-limiting example, a practical case of realisation of the dental suction device and of an assembly of dental suction device and dental turbine to which said device is coupled.

In what follows, two embodiments of the dental suction device of the present invention are described with reference to <FIG>.

The claimed dental suction device comprises suction means comprising a suction body <NUM>, which is preferably a tubular body, capable of being connected to a vacuum source (not shown) suitable for providing preferably a vacuum equal to or greater than <NUM> millibars, for example, <NUM> millibars.

The outer walls of the tubular suction body <NUM> form a first outer cavity or housing <NUM> intended to receive a working head <NUM> of a dental instrument, and a second outer cavity or housing <NUM> intended to receive the handle <NUM> supporting the working head <NUM> of said dental instrument. In the embodiments described and shown in the figures, the outer cavities, or housings <NUM> and <NUM> of the tubular body <NUM> are shaped to receive a working head <NUM> and handle <NUM> of a dental instrument which, in this case, is a dental turbine <NUM> fitted with a drill 6a. However, the same tubular body <NUM> could comprise outer cavities or outer housings adapted to receive the head of a laser and the handle of a dental laser, respectively.

The tubular suction body <NUM> includes a proximal tubular portion "A" capable of being removably attached to the support handle <NUM> of the dental instrument by means of a clamp or by means of a clipping system, and a distal tubular portion "B" sized so that it can be introduced in the oral cavity of a patient.

In the embodiments described, the distal tubular portion "B" extends radially so as to at least partially surround the perimeter of the first outer cavity or outer housing <NUM> receiving the dental instrument working head <NUM>, as well as a portion of the perimeter of the second outer cavity or outer housing <NUM> that receives the neck of support handle <NUM> of the dental instrument working head <NUM>.

In particular, according to one embodiment, the distal tubular portion "B" of the suction tubular body <NUM> extends radially forming a bifurcation "Y" of tubular bodies 1a, 1b, in the form of branches, creating a hollow intermediate space defining the first outer cavity or outer housing <NUM> for the reception of the working head <NUM> of the dental instrument. As can be seen in <FIG>, and in <FIG>, each of the bodies or branches 1a, 1b of the bifurcation "Y" of the distal portion "B" of the tubular body <NUM> extends to surround a perimeter portion of the first outer cavity or outer housing <NUM> of the dental instrument working head <NUM> and incorporates one or more suction orifices <NUM>. The upper edge of the hollow intermediate space forms an access hole <NUM> which allows access to the upper part of the working head <NUM> where the button for clamping the drill 6a is located to allow changing the drill 6a, without the need to disengage the head <NUM> from the interior of the outer cavity or outer housing <NUM>.

The figures of both embodiments of the device show a lower wall <NUM> of the distal tubular portion "B" of the suction body <NUM> which has the particularity that it extends radially outwards from both outer first and second outer cavities or outer housings <NUM> and <NUM> with a width determined by a distance "d", and incorporates the suction orifices <NUM> arranged so as to determine a perimeter area of upward suction of fluid around the outer cavities or outer housings <NUM> and <NUM>.

The distance "d", or width of the lower wall <NUM> of the distal tubular portion "B" of the suction body, <NUM> is sized to absorb fluid deflections forming an angle "α" between <NUM>° and <NUM>° with the axis of the drill 6a or dental laser tip (see <FIG>). In particular, the distance "d" is equal to or greater than <NUM>, preferably between <NUM> and <NUM>, or, advantageously, between <NUM> and <NUM>, as is the case in the embodiment shown in the figures (see <FIG>).

It has been observed that these distances are adequate to provide an extended perimeter suction area that can very efficiently approach the site of projected fluid deflections and ejection of liquids and solids, which are generated inside the oral cavity by the effect of the drill 6a or dental laser, avoiding the leakage of aerosols in the anterior and posterior part of the distal portion "B" of the device.

As regards the suction orifices <NUM> themselves, it should be mentioned that these may be configured as through slots in the lower wall <NUM> of the distal tubular portion "B" of the suction body <NUM>, as shown in <FIG> of the second embodiment.

Preferably, the cross section of these orifices or through suction slots <NUM> determines a fluid passage in the lower wall <NUM> which may be equal to or greater than <NUM> and, optionally, the cross section of the orifices or through slots <NUM> extending on both sides of the second outer cavity or outer housing <NUM> for receiving the handle <NUM> may include walls <NUM> oriented vertically in a radial direction (see <FIG>), towards the area where the deflections would escape. This detail improves the control of aerosol leakage through the rear part of the instrument by favouring a vacuum effect and the maintenance in this rear area of the stable toroidal suction vortex (see <FIG>).

In what follows the operation of the claimed device is described with reference to a dental instrument, which may be, for example, a dental turbine <NUM> provided with a working head <NUM> comprising a drill 6a and pressurised water and air injection means for injecting a pressurised jet of cooling fluid. Dental turbines of this type are available on the market, such as those marketed under the brand names Kaltenbach & Voigt ®, NSK®, or B&W®. Such dental turbines <NUM> include a rotor, which is preferably driven by air compression at a speed of between <NUM>,<NUM> and <NUM>,<NUM> revolutions per minute, and a support handle <NUM> through which the air, water and electricity supply lines extend to the working head <NUM>.

When the operator needs to carry out dental work with a dental turbine <NUM> as described in the previous paragraph, the device claimed is coupled first to the support handle <NUM> of the turbine <NUM>, so that the working head <NUM> is housed inside the first outer cavity or outer housing <NUM> of the tubular suction body <NUM>, and a portion of the support handle <NUM> itself is also housed in the second outer cavity or outer housing <NUM> formed by the same suction body <NUM>. In the embodiments described, the tubular suction body <NUM> is coupled to the support handle <NUM> by means of projections <NUM> provided in the proximal portion "A" of the tubular body <NUM> which are clipped to the support handle <NUM> of the dental turbine <NUM> (see <FIG> and <FIG>).

As can be seen in <FIG> and <FIG>, in the coupled position of the device the lower wall <NUM> of the distal tubular portion "B" of the suction body <NUM>, which includes the orifices <NUM> or suction through slots, surrounds the working head <NUM> and extends towards the rear, covering a part of the perimeter of the housing <NUM> in which the support handle <NUM> is housed. The height of the distal tubular portion "B", and in particular that of the tubular branches or body 1a, 1b, is substantially equivalent to the height of the head <NUM> supporting the drill 6a, which facilitates the handling of the device and dental instrument assembly inside the patient's oral cavity, and more importantly, allows the peripheral suction area determined by the orifices <NUM> or suction through slots to be brought closer to the place where aerosols and fluid deflections are generated.

When the operator operates the dental turbine <NUM> inside the oral cavity, the pressurised spray that cools the drill 6a carries with it, on its way to and from the tooth surface, all kinds of biological products, such as bioaerosols, blood, hard or soft dental tissue, serous or purulent secretions, bacteria, or viruses, among other products and residues. However, thanks to the device of the present invention, while the dental turbine <NUM> is in operation, the peripheral suction area of the distal tubular portion "B" of the suction body <NUM> of the device suctions very efficiently the fluid deflections and ejections of particles milled and dragged by the same fluid.

It has been observed that the trajectory of the fluid deflections and ejections of milled particles is substantially circumscribed within the extended perimeter suction area determined by the orifices <NUM> or suction pass-through slots surrounding the head <NUM> and part of the neck of the handle <NUM>, forming a stable toroidal suction vortex of fluid with its centre in the drill 6a (see <FIG>). Due to this, a very high percentage of these deflections and ejections are absorbed and controlled by the barrier effect generated, in the aforementioned enlarged peripheral area, by the toroidal vortex and the upwards suction.

An additional advantage of the device of the present invention lies in the fact that it makes it possible to dispense with the use of conventional suction cannulas which are manually positioned by an assistant in the vicinity of the dental turbine 6a. It has been observed that these cannulas cannot suction the totality of aerosols, or the splashes or deflections of fluid created by the presence of the cooling fluid of the drill 6a.

The claimed device has the advantage that it envelops the working area in such a way that the aerosols are very efficiently controlled, avoiding the usual leaks that occur with the use of the aforementioned cannulas. Furthermore, in the device of the present invention, the suction area is distributed peripherally, avoiding accidental deviations of cooling fluid that occur due to the lateral suction effect of the aforementioned cannulas. Accidental collisions with these are also eliminated.

Claim 1:
Dental suction device to be coupled to a dental instrument (<NUM>), the dental instrument (<NUM>) being provided with a drill (6a) or laser tip and injection means for injecting under pressure a jet of fluid comprising a mixture of air and water, wherein said dental suction device comprises:
- suction means for suctioning inside the oral cavity deflections of said fluid and aerosols produced by the effect of the drill (6a) or laser tip of the dental instrument (<NUM>), and
- attaching means for removably attaching said dental suction device to the dental instrument (<NUM>)
wherein said suction means comprise a tubular fluid suction body (<NUM>) forming a first outer housing (<NUM>) designed to receive a working head (<NUM>) of the dental instrument (<NUM>) at the outside of the tubular fluid suction body (<NUM>),
wherein a distal tubular portion ("B") of said tubular suction body (<NUM>) surrounds at least partially the perimeter of the first outer housing (<NUM>) for receiving the working head (<NUM>) of the dental instrument (<NUM>), and
- wherein a wall (<NUM>) of the distal tubular portion ("B") incorporates at least one suction orifice (<NUM>) arranged so as to determine a peripheral fluid suction area in an upward direction that at least partially surrounds the first outer housing (<NUM>) for receiving the working head (<NUM>), the distal tubular portion ("B") of the tubular suction body (<NUM>) being sized so that it can be introduced in the patient's mouth while the working head (<NUM>) of the dental instrument (<NUM>) is operating in the first outer housing (<NUM>) of the tubular suction body (<NUM>)