FR3069151A1 - 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

® DEVICE FOR DENTAL TREATMENT.

@) The present invention relates to a device for the disinfection or antisepsis of the endodontium or for the decontamination of the periodontium, comprising, on the one hand, a dental instrument intended to be used in the presence of a solution of irrigation, said dental instrument comprising an active part suitable for endodontic or periodontal treatment and, on the other hand, means for injecting said irrigation solution inside the endodont or at the periodontium.

Said irrigation solution comprises at least hydrogen peroxide (H _{> 2} 0 _{> 2} ) in a concentration of between 1 and 35% (mass / volume).

The device is characterized in that at least the active part of the instrument is made of copper or a copper alloy comprising a proportion of copper greater than or equal to 55% by mass relative to the total mass of the alloy.

9.00E + 00

Bactericidal effect of a fis CuAIBe / H ₂ O ₂ combination on f. faecalis after 30 seconds, contact at 3 € * C

8.00E + 00

7,00E + 00

ST 6.00E + 00

5.00E + 00

2. 4.00E + Û0

3,00E + 00

2.00E4-00

Ι, + ΟΟΕ ΟΟ

Ο, + ΟΟΕ ΟΟ

40 60

100

HjOjimMl concentration

The present invention relates to the dental field and, more particularly, but not limited to, instruments intended 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 way with a solution intended for the disinfection of the endodont or the decontamination of the periodontium of an infected tooth.

The endodont constitutes the internal part of the tooth, containing in particular the pulp which corresponds to a tissue on which the vitality of the tooth depends. With regard to the periodontium, also called periodontium, this term designates the supporting tissues of the tooth, and includes in particular the cementum, the alveolo-dental ligament, the alveolar bone and the gum.

With regard to endodontic treatment, traditionally, the treatment of a dental root whose tissues are damaged consists, firstly, of extracting the pulp from the dental canal, also called endodontium, then, secondly, to put shape and clean said dental canal and finally seal the latter.

The final stage of obturation of the dental canal, after cleaning, is generally carried out using either gutta percha, a gum obtained from natural latex, or various pastes, or even sealing cements. The purpose of this operation is to correctly fill the dental canal from which the pulp has been previously extracted, and in particular at the apical zone of the tooth in order to produce a mechanical sealing zone. Most commonly, the filling is carried out by successive insertion of cones of gutta percha in the dental canal, which are pushed into said canal by the action of a condenser or a compactor.

With regard more specifically to the step of shaping the dental canal, this is generally obtained by successive and scheduled passages of instruments with manual or rotary channels, of the reamers and endodontic file type, and which may have varied geometrical characteristics, in particular in terms of tip diameter, taper, pitch of helical lips, and cross-section and shape.

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

Regarding the cleaning of the canal following the shaping of the latter, such a step is essential to guarantee lasting treatment of the dental root and to avoid any subsequent risk of infection.

At present, the cleaning of the dental canal is carried out by means of canal instruments whose shape and mechanical properties are optimized to allow the most effective evacuation of pulp waste, both organic, mineral, and microbiological, to Outside the canal.

These instruments, generally consisting of a cylindrical or conical wired active tip with a larger diameter of the order of 0.06 to 1 mm and a length of 10 to 20 millimeters, are generally manufactured from 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 trapped by the walls inside a dental canal.

Thus, in US patent document 2013/0240092, a medical instrument of the endodontic instrument type is known, for example, used to clean and conform the dental canal, in particular for the purpose of removing debris before filling said canal by means of '' a filling material. The instrument is manufactured here by means of a monocrystalline alloy with shape memory, for example based on a nickel-titanium combination, copper, or even iron.

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

Thus, the currently recognized procedure for disinfecting and decontaminating the canal system of a tooth is called chemo-mechanical.

More particularly, in this procedure implemented today by practitioners, during the canal preparation of a tooth, there is an alternation of action of metal files and irrigation solutions using, for example d sodium hypochlorite concentrated between

0.5% and 5%.

Preferably, canal preparation ends with a final irrigation protocol which successively uses

Sodium hypochlorite, EDTA (ethyl diamine tetra acetic acid) and distilled water or physiological saline.

Thus, to date, no procedure has been implemented which allows, simultaneously, mechanical cleaning of the walls of the canal and its disinfection.

However, in pulp necrosis and endodontic treatments in proven failure, are found, within the canal 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 clear that the most complete disinfection of the dental canal is essential in order to limit the failure rate of endodontic treatments.

In this goal, it was imagined the implementation, through example in end of canal cleaning of a jet of peroxide hydrogen at a concentration of 1 'order of 900 at 1000

millimoles per liter.

Thus, for example, in the state of the art, document US 2006/0223026 is also known, relating to a liquid injection cannula or needle, made of metal, alloy, resin or stainless steel and which can be put 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 improving the treatment and disinfection of the dental canal in endodontics, it is not yet

not optimal and he stays at improve the effectiveness of the disinfection root canal so lead to one reduction substantial bacteria contaminating within from the canal dental before obstruction of this latest.

The invention offers the possibility of overcoming, at least in part, the various drawbacks of the state of the art by proposing a device comprising a mechanized or manual dental instrument associated with an irrigation solution to result in almost total disinfection. of the endodont before closing it, or even to decontaminate the periodontium.

To this end, the present invention relates to a device for the disinfection or antisepsis of the endodontium or for the decontamination of the periodontium, comprising, on the one hand, a dental instrument intended to be used in the presence of a solution of irrigation, said dental instrument comprising an active part suitable for endodontic or periodontal treatment and, on the other hand, means for injecting an irrigation solution inside the endodont or at the periodontium, said solution irrigation comprising at least hydrogen peroxide (H ₂ O ₂ ) in a concentration between 1 and 35% (mass / volume), said device being characterized in that, at least, the active part of the instrument is made of copper or a copper alloy comprising a proportion of copper greater than or equal to 55% by mass relative to the total mass of the alloy.

According to the standards of AFNOR (French Standardization Agency), and within the meaning of the present invention:

- the term "disinfection" of an inert surface with a disinfectant is an operation with a temporary result, making it possible to eliminate or kill microorganisms and / or to inactivate unwanted viruses carried by inert media contaminated according to goals set. The result of this operation is limited to the microorganisms and / or viruses present at the time of

1'opération.

- antisepsis is an operation with a temporary result allowing, at the level of living tissues, and within the limit of their tolerance, to eliminate or kill micro-organisms and / or to inactivate viruses according to the objectives set. 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 term disinfection (adapted to inert tissues in the case of a tooth which is no longer alive) and the term antisepsis (applying to living tissues) are suitable for treatment endodontic.

- the term “decontamination” of a surface is an operation with a temporary result, making it possible to eliminate, kill or inhibit undesirable microorganisms according to the objectives set. 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 in that inhibiting microorganisms means inhibiting their growth, so decontamination does not necessarily involve the elimination of microorganisms.

In the context of the invention, the term decontamination is suitable for application in 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 HEPES buffer 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-1-26 acid (bis-ethanesulfonic), diluted in a phosphate buffer, the concentration of said PIPES buffer in said irrigation solution being between 0.5 and 4 millimoles per liter (mmol / L or mM).

Said irrigation solution may also contain, most preferably, 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.

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

Advantageously, the device of the invention may also comprise, in addition to the means for injecting the irrigation, a second injection means containing a bicarbonate buffer solution capable of 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 of the device of the invention consists of a canal instrument comprising an active part able to be introduced into

Inside a dental canal.

Other characteristics and advantages of the invention will emerge from the detailed description which follows of nonlimiting embodiments of the invention, with reference to the appended figures in which:

- Figure 1 is a graph representing the logarithmic lowering of the number of colony forming units per mL (log (CFU / mL)) of Enterococcus faecalis as a function of the concentration of hydrogen peroxide (H2O2) in mmol / L

(mM) illustrating 1'effet bactericide of a combination between an alloy CuAlBe and a solution of peroxide hydrogen H2O2 sure a Enterococcus strain faecalis after 30 seconds of contact at 36 ° C; Figure 2 is a graph similar to the figure 1 illustrating this time fungicidal effect of the

combination of a CuAlBe alloy and a hydrogen peroxide solution H2O2 on the fungus strain

Candida albicans.

The remainder of the description endeavors to describe a preferred embodiment of the device of the invention, in which the dental instrument consists of an instrument intended for the treatment of the endodont. The dental instrument is then called “canal instrument”, and is able to be introduced at the level of the dental canal as will be described in more detail below.

The instrument in endodontic use can be a canal shaping or preparation instrument and / or a canal finishing instrument.

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

The present invention therefore relates, in a particular embodiment, to a device for the disinfection or antisepsis of the endodont comprising, on the one hand, a canal instrument, either manual or mechanized, and comprising, in particular, an active part which is intended to penetrate the dental canal in order to clean it, rid it of pulp debris, while allowing disinfection or antisepsis before obturation of said canal by means, for example, of gutta percha.

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

1'alliage.

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

In a variant, one of the ends of the active part of the canal instrument is terminated by a gripping part adapted to be connected to a tool holder of the contra-angle type or handpiece.

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

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

The active part of the canal instrument 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 inside 1 endodont or at the periodontal level.

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 hydrogen peroxide H ₂ O ₂ in a mass concentration (m / V) suitable for disinfecting the dental canal and advantageously between 1 and 35%, and more preferably still between 1 and 10%, the most advantageous H ₂ O ₂ 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 the invention.

This injection means preferably consists of a sterile pod ready for use and single use, having the shape of a small flexible plastic tube with an opening of small diameter closed by a breakable plug.

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

It is also conceivable that the active part of the canal instrument constitutes a means of injecting the irrigation solution based on hydrogen peroxide directly into the dental canal, with the aim of allowing cleaning and disinfection particularly optimal of it.

Whatever the embodiment of the device chosen, the disinfection of the endodont (or periodontium) is substantially improved by means of said device according to

comparison with

'invention,

technical.

mass

55% copper

copper,

irrigation

allows concentration with a

previously,

a

optimal

1'endodonte.

Copper is known for its antimicrobial properties and the particular association 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 at l against contaminating bacteria or fungi present in the dental canal.

Indeed, by combining a copper alloy with a H ₂ O _{2 solution} , an almost instantaneous reaction of dissociation of hydrogen peroxide takes place with the 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 microorganisms, since they cause destruction of the membranes and cause intracellular oxidative stress ultimately leading to the destruction of the DNA of the microorganisms.

To return now to the canal instrument which comprises the device of the invention, and more particularly to the alloy used to manufacture it, it advantageously consists of an alloy consisting, in addition to copper, aluminum and beryllium. This alloy is denoted CuAlBe.

In this preferred embodiment, the proportion of aluminum within the alloy used for the manufacture of the canal instrument is between 11 and 12% by mass relative to the total mass of the alloy, the proportion in beryllium being between 0.5 and 0.6% by mass relative to the total mass of the alloy, the remainder being copper.

The alloy in which the canal instrument is made can also be an alloy made of copper, aluminum, beryllium and nickel, denoted CuAlBeNi.

The composition of this alloy consists of a proportion of aluminum of between 11 and 12%, preferably equal to 11.5%, by mass relative to the total mass of the alloy, the proportion of beryllium is between 0.3 and 0.5% by mass relative to the total mass of the alloy, preferably equal to 0.4%, and the proportion of nickel is 3.5 to 4%, preferably equal to 3, 8%, the remainder of the composition being copper.

Irrespective of the composition of the alloy used to manufacture the canal instrument, and most preferably, the irrigation solution injected in association with this instrument comprises, in addition to the hydrogen peroxide, either a solution of HEPES buffer (acid 4- (2-hydroxyethyl) -1piperazine ethane sulfonic), i.e. a PIPES buffer (piperazine-1-2- acid (bis-ethanesulfonic).

Whatever the buffer, HEPES or PIPES, associated with the hydrogen peroxide within the irrigation solution, this 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 possible, very advantageously, to further improve the radical oxidation and, consequently, the disinfection of the treated dental canals. by means of 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, further improves the intensity and the duration of production of the radical compounds resulting from the contact between the peroxide hydrogen of said irrigation solution and copper metal of the active part of the canal instrument.

This irrigation solution, composed of H ₂ O ₂ and optionally a HEPES or PIPES buffer, can also preferably be supplemented with ascorbic acid which catalyzes the Haber-Weiss and Fenton reactions.

More preferably still, in such an embodiment, 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 also comprise, in addition to the first injection means which serves to diffuse the irrigation solution, as the case may be at 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 bicarbonate buffer has the effect of stopping the reaction between the copper of the active part and the irrigation solution.

Finally, in a particularly advantageous manner, the dental instrument which the device of the invention comprises may constitute a means of transmitting sounds and / or ultrasound and / or a laser beam.

Other advantages and characteristics 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 between a CuAlBe alloy and a solution of hydrogen peroxide H ₂ O ₂ 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 H ₂ O ₂ and an instrument made of CuAlBe copper alloy comprising 11.60% by mass, relative to the total mass alloy, aluminum and 0.52% by mass of beryllium, the rest being copper, was tested.

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

Then add the PBS buffer, 1 mL of HEPES (or PIPES), the necessary volume of hydrogen peroxide, depending on the desired final concentration, and finally 1 mL of bacterial suspension (Enterococcus faecalis ATCC 29212, in phase of second or third generation growth at a concentration between 10 ⁸ and 10 ⁹ bacteria / mL).

The final volume of the experimental medium is 10 mL, the volume of PBS is adjusted as a function of the volume of H ₂ O ₂ . After each addition, vortexing is carried out. 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 catalase at 1 mg / ml is added in order to neutralize the hydrogen peroxide.

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

The dishes thus poured are incubated in an oven at 37 ° C ± 1 ° C for 44h ± 4h, the counting can then be carried out.

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

The results obtained, appearing on the graph in FIG. 1, illustrate a substantial decrease in the number of Colonies-forming Units (CFU / mL) as a function of the H ₂ O ₂ concentration expressed in mmol / L (mM).

Example 2: Fungicidal effect of a combination between a CuAlBe alloy and a hydrogen peroxide H ₂ O _{2 solution} on a Candida albicans strain after 30 seconds of contact at 36 ° C:

The applicant also tested the fungicidal effect on C. albicans of the combination between an irrigation solution comprising hydrogen peroxide H ₂ O ₂ , and an instrument made of copper alloy CuAlBe comprising 11.60% by mass, relative to the total mass of the alloy, aluminum and 0.52% by mass of beryllium, the rest being copper.

The procedure followed is similar to that used for the measurement of the bactericidal effect of the invention on a strain 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, in the second or third generation growth phase at a concentration between 10 ⁸ and 10 ⁹ cells / mL. The added volume is also lmL.

The results obtained, appearing on the graph in FIG. 2, illustrate a substantial decrease in the number of Colonies-forming Units (CFU / ml) as a function of the H ₂ O ₂ concentration expressed in mmol / L (mM).

Claims (6)

1. Device for the disinfection or antisepsis of the endodontium 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 a active part suitable for endodontic or periodontal treatment and, on the other hand, a means for injecting said irrigation solution inside the endodont or at the periodontium, said irrigation solution comprising at least peroxide hydrogen (H ₂ O ₂ ) in a concentration between 1 and 35% (mass / volume), said device being characterized in that at least the active part of the instrument is made of copper or a copper alloy comprising a proportion of copper greater than or equal to 55% by mass relative to the total mass of the alloy. previous Igation device includes, concentration HE PE S said irrigation solution being between 0.5 and 4 Device according to claim 1, characterized in that irrigation concentrati on irrigation 4. Device according to any one of the preceding claims, characterized in that the said irrigation solution comprises 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 shape memory. Device according to the preceding claims, characterized in that it comprises, in addition to the injection medium irrigation. injection Previous device claims 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 canal instrument comprising an active part able to be introduced inside a dental canal. 10. Device according to any one of the preceding claims, characterized in that the dental instrument constitutes a means of transmitting sounds and / or ultrasound and / or a laser beam.