FR3069151B1 - DEVICE FOR DENTAL TREATMENT - Google Patents

Abstract

The present invention relates to a device for the disinfection or antisepsis of the endodont or for the decontamination of the periodontium, comprising, on the one hand, a dental instrument intended to be used in the presence of an irrigation solution, said dental instrument comprising an active part suitable for endodontic or periodontal treatment and, secondly, a means for injecting said irrigating solution inside the endodontum or at the level of the periodontium. Said irrigation solution comprises at least hydrogen peroxide (H2O2) in a concentration of between 1 and 35% (weight / volume). The device is characterized in that at least the active part of the instrument is made of copper or copper alloy comprising a proportion of copper greater than or equal to 55% by weight relative to the total mass of the alloy.

Description

The present invention relates to the dental field and, more particularly, but not exclusively, instruments for cleaning the dental canal or the periodontium of an infected tooth.

Even more specifically, the invention relates to a device in which a dental cleaning instrument is associated in an original manner with a solution for endodontal infection or decontamination of the periodont of an infected tooth. The endodont constitutes the inner part of the tooth, containing in particular the pulp which corresponds to a tissue whose vitality depends on the tooth. Regarding the periodontium, also called periodontium, this term refers to the tissues of the support of the tooth, and includes in particular the cementum, the ligamentalvéolo-dental, the alveolar bone and the gingiva.

With regard to endodontic treatment, traditionally, the treatment of a dental root whose tissues are damaged consists, first, in extracting the pulp of the dental canal, also called endodontum, then, in a second stage, in shaping and cleaning said dental canal and finally closing the latter. The final step of sealing the dental canal, after cleaning, is usually carried out using either guttapercha, a gum from the natural latex, or pastadiverses, or even cement cements. The purpose of this operation is to correctly perform a filling of the dental canal whose pulp has been previously extracted, and in particular at the apical zone of the tooth to achieve a mechanical sealing zone. Most commonly, the filling is effected by successive insertion of degutta percha cones into the dental canal, which are pushed into said channel by the action of a condenser or a compactor.

More specifically, the step of setting up the dental canal, it is obtained, generally, successive and sequential laparations of instruments with manual or rotary channels, reamers type and endodontic files, and can present various geometric characteristics, in particular in terms of tip diameter, taper, pitch of helical lips, and sectional cut and shape.

This shaping generates a more or less curved, conical canal whose smaller diameter is located at the level of the root apex, while the largest diameter is located on the side of the pulpal floor.

As for the cleaning of the canal following the establishment of the latter, such a step is essential to guarantee a lasting treatment of the dental root and avoid any subsequent risk of infection. At present, the cleaning of the dental canal is carried out by means of root canal instruments whose shape and mechanical properties are optimized to permit the most efficient evacuation of the pulp waste, organic, inorganic and microbiological, to the outside of the canal. channel.

These instruments, generally consisting of a cylindrical or conical wire-shaped bonding point with a larger diameter of the order of 0.06 to 1 mm and a length of 10 to 20 millimeters, are generally made of nickel-titanium alloy or stainless steel, materials chosen for their mechanical properties, and in particular their resistance to torsion, this characteristic being essential to avoid breaking the instrument wedged by the walls inside a dental canal.

Thus, patent document US 2013/0240092 discloses a medical instrument of the endodontic type, for example, used for cleaning and conforming the dental canal, in particular for the purpose of removing debris before filling said canal with a piece of equipment. shutter. The instrument is manufactured here by means of a monocrystalline shape memory alloy, for example based on a combination nickel-titanium, copper, or even defer.

Mechanical canal instruments of this type are usually used alternately with irrigation solutions in the form of a jet of fluid, such as water, for the purpose of mechanically driving the pulp waste towards the outside of the tooth.

Thus, the currently recognized procedure for disinfection and decontamination of the ductal system of unedent is called chemo-mechanical.

More particularly, in this procedure nowadays practiced by practitioners, during the canal preparation of a tooth, alternating action of metal limes and irrigation solutions using, for example sodium hypochlorite Concentrated between 0.5% and 5% .Preferentially, the canal preparation terminates in a final irrigation protocol which successively uses sodium hypochlorite, EDTA (ethyl diamine tetraacetic acid) and distilled water or saline.

Thus, to date, no procedure has been implemented which simultaneously makes it possible to mechanically clean the walls of the canal and disinfect it.

However, in pulp necrosis and endodontic treatments in proven failure, are found, within the ductal system of an infected tooth, between 2 and 30 different species of microorganisms including the most resistant strains, such as for example Enterococcus faecalis in 78% of cases and Candida albicans in 20% of cases.

Therefore, it is understandable that the most complete disinfection of the dental canal is essential in order to limit the failure rates of endodontic treatments.

For this purpose, it has been imagined the implementation, for example at the end of canal cleaning of a jet of hydrogen peroxide at a concentration of the order of 900 to 1000millimol per liter.

Thus, for example, in the state of the art, document US 2006/0223026 relating to a cannula or needle for injection of liquid, made of metal, alloy, resin or stainless steel and that can be implemented in dental treatment. Through a plurality of orifices, this cannula allows the injection of a cleaning liquid based on 10% sodium hypochlorite and 3% hydrogen peroxide.

However, although such a solution is interesting in the search for improvement of the treatment and disinfection of the dental canal in endodontics, it is still not optimal and it remains to improve the efficiency of the canal disinfection to achieve a Substantial reductions of contaminating bacteria in the canaldentary prior to obstruction of the canaldentary. The invention offers the possibility of mitigating, at least in part, the various disadvantages of the state of the art by proposing a device comprising a mechanized or manual dental instrument associated with an irrigation solution to end up with the almost complete disinfection of the endodont before shutting it down, or even to decontaminate the periodontium. To this end, the present invention relates to a device for the disinfection or antisepsis of the endodont or for the decontamination of the periodontium, comprising, firstly, a dental instrument intended to be used in the presence of an irrigation solution, said instrument dental system comprising an active part suitable for endodontic or periodontal treatment and, secondly, a means for injecting an irrigation solution into the interior of the endodon or the periodontium, the irrigation solution comprising at least one of hydrogen peroxide (H2O2) in a concentration of between 1 and 35% (w / v), said device being characterized in that at least the active part of the instrument is made of copper or copper alloy comprising a proportion of brass greater than or equal to 55% by mass relative to the total mass of the alloy.

According to the standards of AFNOR (French Agency for Normalization), and within the meaning of the present invention: - the term "disinfection" of an inert surface with disinfectant is an operation with momentary result, allowing to eliminate or kill micro -organisms and / or inactivate unwanted viruses carried by inert contaminated media according to the objectives set. The result of this operation is limited to the microorganisms and / or viruses present at the time of the operation. - antisepsis is an operation with a temporary result, in the living tissues, and in the limit of their tolerance, to eliminate or kill the microorganisms and / or to inactivate the viruses according to the fixed objectives. The result of this operation is limited to the microorganisms present at the time of the operation.

In the context of the invention, both the termedisinfection (adapted to inert tissues in the case of a toothwhich is no longer alive) than the term antisepsis (applicable to living tissues) are suitable for endodontic treatment. the term "decontamination" of a surface is an operation with a momentary result, making it possible to eliminate, kill or inhibit the undesirable micro-organisms according to the fixed objectives. The result of this operation is limited to the microorganisms present at the time of the operation. Therefore, the definition of decontamination differs from that of disinfection by the fact that inhibiting microorganisms means inhibiting their growth, so decontamination does not necessarily imply the elimination of microorganisms.

In the context of the invention, the term decontamination is adapted to an application in the periodontal treatment.

According to a particularly advantageous embodiment, said irrigation solution comprises, in addition to hydrogen peroxide, a HEPES buffer (4- (2-hydroxyethyl) -1-piperazine ethane sulfonic acid), diluted in a phosphate buffer, the concentration of said buffer HEPES in said irrigation solution being between 0.5 and 4 millimoles per liter (mmol / L or mM).

In a different but equally advantageous embodiment, said irrigation solution comprises, in addition to hydrogen peroxide, a PIPES buffer (piperazine-1-2- (bis-ethanesulphonic acid), diluted in a phosphate buffer, concentration of said buffer PIPES in said irrigation solution being between 0.5 and 4 millimoles per liter (mmol / L or mM).

Said irrigation solution may also include, more preferably, ascorbic acid in a final concentration of between 1 and 10 mg / l, preferably between 3 and 8 mg / l and, more preferably, between 5 and 6 mg / l.

Interestingly, said active part of the instrument is made of copper alloy memory monocrystalline or polycrystalline form.

Advantageously, the device of the invention may also comprise, in addition to the injection means of the irrigation solution, a second injection means containing a bicarbonate buffer solution suitable for being introduced after said irrigation solution. The dental instrument of the device of the invention can be either manual or mechanized.

Most preferably, the dental instrument ofdispositif of the invention consists of a canalair instrumentcomprenant an active part capable of being introduced into the interior of a dental canal. Other characteristics and advantages of the inventionwillbe set forth in the following detailed description of the nonlimiting embodiments of the invention, with reference to the appended figures in which: FIG. 1 is a graph representing the logarithmic lowering of the number of units; colonies per ml (log (CFU / mL)) of Enterococcus faecalis as a function of concentration in hydrogen peroxide (H2O2) in mmol / L (mM) illustrating the bactericidal effect of a combination between a CuAlBe alloy and a solution of H2O2 hydrogen peroxide on a strain of Enterococcus faecalis after 30 seconds of contact at 36 ° C; FIG. 2 is a graph similar to FIG. 1, this time illustrating the fungicidal effect of the combination between a CuAlBe alloy and a solution of hydrogen peroxide H2O2 on the fungus strainCandida albicans.

The remainder of the description attempts to describe a preferred embodiment of the device of the invention, in which the dental instrument consists of an instrument for the treatment of the endodont. The dental instrument is referred to as a "canal instrument" and is capable of being introduced at the level of the dental canal as will be described in more detail below. The instrument in endodontic use may be a canal shaping or preparation instrument and / or a canal finishing instrument.

However, the present invention should not be considered as limiting to a device having a root canal instrument. Indeed, the device according to the inventionmay also be applied to the treatment of the periodontium, and more particularly to the decontamination thereof. The periodontal area groups all of the supporting tissues of the tooth, particularly the gums or the periodontal pocket, the latter corresponding to a space between the tooth and the gum that is likely to form during periodontal disease. Also, the present device is also able to allow a particularly effective decontamination of the faceradicular and soft tissues of a periodontal pocket in this type of disease.

The present invention thus relates, in a particular embodiment, to a device for the disinfection or antisepsis of the endodont comprising, on the one hand, a ductal instrument, indifferently manual or mechanized, andcomprising, in particular, an active part which is intended to penetrate the dental canal to clean it, remove pulp debris, while allowing disinfection or uniseisepsie before closing said channel by, for example, gutta percha.

Essentially, at least the active part of the canal instrument which is equipped with the device is made of copper or a cuprous alloy. In the latter case, the cuprous alloy comprises a proportion of brass greater than or equal to 55%, relative to the total mass of the alloy.

The active part of the root canal instrument is preferably extended by a manual grip handle to facilitate the use of the instrument.

In one variant, one of the ends of the active portion of the root canal instrument is terminated by a depression portion adapted to be connected to a tool holder of a cross-angle or handpiece type.

In one embodiment of the invention, this active portion of the root canal can be substantially conical and its surface can be smooth, without asperity and without sharp edges or not. The instrument can thus be used as a canal preparation finisher, for example.

In another example, the active part may be of substantially conical shape and have edges, sharp or not, and whatever its shape. The canal instrument can then be used as a reamer.

The active part of the root canal is intended, in the device of the invention, to be used in association with a liquid, consisting of an irrigation solution, the latter being intended to be injected into the interior of the endodont or at the level of the periodontium.

Also, the device of the invention also comprises at least one means for injecting said irrigation solution, the latter being based on hydrogen peroxide or oxygenated water H2O2 in a mass concentration (m / V) appropriate for disinfecting the dental canal. and advantageously between 1 and 35%, and more preferably between 1 and 10%, the most interesting H2O2 concentration being of the order of 3%, or equal to 3%.

Said injection means is advantageously capable of containing a volume of between 0.5 and 20 ml, sufficient for effective disinfection of a root canal with the instrument of 1'invention.

This injection means preferably consists of dosettestérile ready-to-use and disposable, having the form of a small flexible plastic tube with a small diameter opening closed by a breakable stopper.

According to one variant, the hydrogen peroxide-based irrigation solution is packaged in a burette closed by a plug through which the active part of the electrode instrument passes.

It is also conceivable that the active part of the ductal instrument is a means of injecting the hydrogen peroxide irrigation solution directly into the dental canal, with a view to enabling particularly optimal cleaning and disinfection of this canal. this.

Whatever the embodiment of the device chosen, the disinfection of the endodont (or periodontium) is substantially improved by means of said device according to the invention, in comparison with the instruments currently existing in the state of the art.

Indeed, it was found by the plaintiff that a combination of a copper instrument, or an alloy of more than 55% by weight of copper, with an H 2 O 2 solution in a concentration such that previously defined, allows in particular an optimal disinfection of the endodont.

Copper is known for its antimicrobial properties and the particular combination of an instrument comprising a proportion greater than or equal to 55% with an irrigation solution as described above allows a substantial improvement in the effectiveness of copper against bacteria or of contaminating fungi present in the dental canal.

Indeed, by combining a copper alloy with an H2O2 solution, there is a quasi-instantaneous reaction dissociation of hydrogen peroxide with production of hydroxyl free radicals according to the Haber-Weiss and Fenton reaction.

These hydroxyl radicals, derived from oxygen, are the most effective free radicals to fight against contaminating micro-organisms, because they cause destruction of the membranes and cause intracellular oxidative stress ultimately leading to destruction of microorganism DNA.

Returning now to the canal instrument that includes the device of the invention, and more particularly to the alloy used to make it, the latter isagageusement an alloy consisting, besides copper, aluminum and beryllium. This alloy is noted CuAlBe.

In this preferred embodiment, the proportion of aluminum within the alloy used for the manufacture of the root canal instrument is between 11 and 12% by weight relative to the total mass of the alloy, the enberyllium proportion being between 0.5 and 0.6% by weight relative to the total weight of the alloy, the balance being copper. The alloy in which the channel instrument is manufactured may also be an alloy consisting of copper, aluminum, beryllium and nickel, noted CuAlBeNi.

The composition of this alloy consists of a proportion of aluminum of between 11 and 12%, preferably equal to 11.5% by weight relative to the total weight of the alloy, the proportion of beryllium is between 0.3 and0.5% by weight relative to the total weight of the alloy, preferably 0.4%, and the proportion of nickel is 3.5 to 4%, preferably 3.8%, the remainder of the composition being copper.

Regardless of the composition of the alloy used to make the canal instrument, and most preferably, the irrigation solution injected in combination with this instrument comprises, in addition to hydrogen peroxide, a solution of HEPES buffer (4- ( 2-hydroxyethyl) -1-piperazine ethanesulfonic acid), or a PIPES (piperazine-1-2- (bis-ethanesulfonic acid) buffer.

Whatever the buffer, HEPES or PIPES, associated with hydrogen peroxide in the irrigation solution, it is diluted in a phosphate buffer.

In addition, the HEPES or PIPES buffer is present in the irrigation solution at a final concentration of between 0.5 and 4 mmol / L. The addition to the irrigation solution of a HEPES or PIPES buffer in the concentration range indicated makes it very interesting, to further improve theradical oxidation and, consequently, the disinfection of the dental canal treated with the device. of the invention.

The presence of a phosphate buffer, in which the HEPES or PIPES buffer is diluted before addition to the irrigation solution, makes it possible to further improve the intensity and duration of production of the radical compounds resulting from the contact between hydrogen peroxide and said irrigation solution and the copper metal of the active part of the root canal.

This irrigation solution, composed of H2O2 and optionally a HEPES or PIPES buffer, can also be supplemented, preferably, with ascorbic acid which catalyzes the Haber-Weiss and Fenton reactions.

More preferably still, in such a mode of realization, the ascorbic acid is present in the irrigation solution at a final concentration of between 1 and 10 mg / l, preferably between 3 and 8 mg / l and, more preferably still, between 5 and 6 mg / L.

The device of the invention may further comprise, in addition to the first injection means which serves to diffuse the irrigation solution, as the case may be in the periodontium or in the dental canal, a second injection means for a bicarbonate buffer solution, preferably introduced after said irrigation solution. This addition of buffer bicarbonate has the effect of stopping the reaction between the cuivrede of the active part and the irrigation solution.

Finally, particularly advantageously, the dental instrument that comprises the device of the invention may constitute a means of transmitting sound and / or ultrasound and / or a laser beam. Other advantages and features of the invention will also appear on reading the following examples, given by way of illustration and not limitation.

Example 1: Bactericidal effect of a combination of a CuAlBe alloy and a solution of hydrogen peroxide H2O2 on a strain d '' Enterococcus faecalis after 30 seconds of contact at 36 ° C: The bactericidal effect on E. faecalis of the combination between an irrigation solution comprising hydrogen peroxide H2O2 and an instrument made of CuAlBe copper alloy comprising 11.60% by weight, by relative to the total mass of the alloy, aluminum and 0.52% by mass of beryllium, the remainder being fired, was tested.

To do this, a sterile CuAlBe alloy rod, in the proportion defined above, was deposited at the bottom of a test tube.

PBS buffer, 1 ml of HEPES (or PIPES), the required volume of hydrogen peroxide, depending on the desired final concentration, and finally 1 ml of bacterial suspension (Enterococcus faecalis ATCC 29212, in the second growth phase, are then added. or third generation at concentration between 108 and 109 bacteria / mL).

The final volume of the experimental medium is 10 ml, the volume of PBS is adjusted according to the volume of H2O2. After each addition, vortexing is performed. The order of addition of the different reagents must be respected.

The tubes are placed in a water bath at 37 ° C. ± 1 ° C. for 30 seconds.

Once the contact time has elapsed, 1 ml of 1 mg / ml decatalase is added in order to neutralize the hydrogen peroxide.

1 ml of the suspension is removed after stirring and carried out spreading by incorporation into 20 ml of CASO agar (soy casein).

The boxes thus cast are incubated in an oven at 37 ° C ± 1 ° C for 44h ± 4h, the counting can then be performed.

The actual number of bacteria in CFU / mL is then calculated from the number of colonies obtained divided by the actual volume, taking into account the dilution performed.

The results obtained, appearing in the graph of FIG. 1, illustrate a substantial decrease in the number of Forming Units (CFU / mL) as a function of concentration in H2O2 expressed in mmol / L (mM).

EXAMPLE 2 Fungicidal Effect of a Combination of CuAlBe Alloy and H2O2 Hydrogen Peroxide Solution on a Candida Albicans Strain After 30 Seconds of Contact at 36 ° C.

The applicant has also tested the fungicidal effect on C.albicans of the combination between an irrigation solutioncomprising hydrogen peroxide H2O2, and an instrument made of CuAlBe copper alloy comprising 11.60% by weight, relative to the mass. total of the alloy, aluminum and 0.52% by mass of beryllium, the balance being copper.

The procedure followed is similar to that used for measuring the bactericidal effect of the invention on a layer of E. faecalis in Example 1 above, except that the suspension added after the hydrogen peroxide is a fungal suspension of Candida albicans ATCC 102301, growth stage of second or third generation at a concentration of between 108 and 109 cells / mL. The volume is also lmL.

The results obtained, appearing in the graph of FIG. 2, illustrate a substantial decrease in the number of Forming Units (CFU / mL) as a function of concentration in H2O2 expressed in mmol / L (mM).

Claims (10)

1. Device for the disinfection or antisepsis of the endodon or for the decontamination of the periodontium, comprising, on the one hand, a dental instrument intended to be used in the presence of an irrigation solution, said dental instrument comprising an active part capable of endodontic or periodontal treatment and, on the other hand, a means for injecting the irrigation solution into the interior of the endodon or periodontal surface, said irrigation solution comprising at least hydrogen peroxide (H2O2) in a concentration between 1 and 35% (w / v), said device being characterized in thatat least the active part of the instrument is made of copper or copper alloy comprising a proportion of copper greater than or equal to 55% by weight relative to the total mass of the alloy. 2. Device according to the preceding claimacharacterized in that said irrigation solution comprises, in addition to hydrogen peroxide, a buffer HEPES (4- (2-hydroxyethyl) -1-piperazine ethane sulfonic acid), diluted in a phosphate buffer, the concentration of said HEPES buffer in said irrigation solution being between 0.5 and 4millimoles per liter. 3. Device according to claim 1 characterized in that said irrigation solution comprises, besides the hydrogen peroxide, PIPES buffer (piperazine-1-2- (bis-ethanesulfonic acid), diluted in a phosphate buffer, laconcentration said PIPES buffer in said irrigation solution being between 0.5 and 4 millimoles per liter. 4. Device according to any one of the preceding claims, characterized in that said irrigation solutioncomprises ascorbic acid in a final concentration of between 1 and 10 mg / L, preferably between 3 and 8 mg / L and, more preferably still , between 5 and 6 mg / L. 5. Device according to any one of the preceding claims characterized in that said active part of the instrument is made of copper alloy with monocrystalline or polycrystalline form of memory. 6. Device according to any one of the preceding claims characterized in that it comprises, besides the averend'injection of the irrigation solution, a second averend'injection of a bicarbonate buffer solution suitable for being introduced after said irrigation solution . 7. Device according to any one of the preceding claims characterized in that the dental instrument is manual. 8. Device according to any one of claims 1 to 6 characterized in that the dental instrument is mechanized. 9. Device according to any one of the preceding claims characterized in that the dental instrument consists of a root canal instrument comprising an active portion capable of being introduced into a dental canal. 10. Device according to any one of the preceding claims characterized in that the dental instrument is a sound transmission means and / or ultrasound and / or a laser beam.