Micellar solution for endodontic and / or oral cleaning
A micellar solution with phospholipids and chelating agents addresses the inefficiencies of current endodontic treatments by providing a non-toxic, stable, and effective biofilm removal method for root canals, ensuring safe and efficient disinfection.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- COLTENE WHALEDENT AG
- Filing Date
- 2025-11-04
- Publication Date
- 2026-05-15
AI Technical Summary
Current endodontic solutions for removing biofilm and bacteria in root canals are time-consuming, toxic, and can cause undesirable interactions and precipitates, posing risks to patients and compromising treatment efficacy.
A micellar solution comprising phospholipids and chelating agents, such as citric acid, is used to effectively remove biofilm and bacteria without hydrogen peroxide, ensuring non-toxicity and stability, with a pH range of 1.5 to 6.5, enhancing bacterial removal and preventing reinfection.
The micellar solution effectively removes biofilm and bacteria, stabilizes the solution, and prevents dentine discoloration, ensuring safe and efficient endodontic disinfection without harmful side effects.
Smart Images
Figure EP2025081797_15052026_PF_FP_ABST
Abstract
Description
[0001] Micellar solution for endodontic and / or oral cleaning
[0002] The invention relates to a micellar solution for endodontic and / or oral cleaning, in particular endodontic and / or oral disinfection, according to the independent claim .
[0003] In endodontic treatments , the obj ective of any chemical cleaning of the root canal is to heal and prevent endodontic infections caused by planktonic bacteria and biofilm . A biofilm is formed by thin-layered condensations of microorganisms as for example , bacteria, fungi , protozoa, that naturally colonise various surface structures . The microorganisms aggregate to form a colony with a complex structure that adheres to a surface with a smear layer that protects the microorganisms from harmful exogenous influences such as antimicrobial agents and a variety of disinfectants used in the treatment of endodontic infections . The smear layer is a porous layer of amorphous structures of organic particles consisting of coagulated proteins , necrotic and pulpal tissue debris , microorganisms and inorganic particles of minerals from dentine structure . For success ful treatment of endodontic diseases the whole biofilm and bacteria should ideally be removed in order to prevent reinfection .
[0004] In the prior art the removal of this biofilm is achieved by mechanical debridement and chemical cleaning . The chemical cleaning has so far only been achieved by applying a number of di fferent irrigation solutions which is time consuming . Current endodontic solutions like sodium hypochlorite and chlorhexidine are associated with certain toxicity potential . Sodium hypochlorite for example can cause serious inj uries to the patient i f extruded into the periodontium . Further, the combination of different irrigation solutions has led to undesirable interactions, which have resulted in, for example, precipitation of carcinogenic para-chloroaniline or a reduction in efficacy.
[0005] WO 2021 / 171263 describes a micellar disinfectant for the cleaning of hard surfaces. The disinfectant uses hydrogen peroxide in concentrations ranging from 0.05 to 2.5 w / w% of the total weight of the composition. However, hydrogen peroxide is considered as substance, which, if used separately, would be considered a medicinal product and has a secondary action to that of the device of which it is an integral part. As such, the composition would be classified as class III device according to EU MDR - Medical Device Regulation 2017 / 74, associated with a higher risk.
[0006] It is thus an object of the present invention to overcome at least some of the drawbacks outlined above, e.g. to provide a micellar solution for endodontic and / oral cleaning, in particular for endodontic and / or oral disinfection, that is easy to use, and / or has less toxicity potential. This objective is solved by a micellar solution for endodontic and oral uses according to the independent claims. Preferred embodiments are defined in the dependent claims and throughout this specification.
[0007] Pursuant to the invention, a micellar solution for endodontic and / or oral cleaning, in particular for endodontic and / or oral disinfection, comprises a phospholipid (i.e., at least one phospholipid) and a chelating agent (i.e., at least one chelating agent) . The chelating agent is comprised in a concentration between 5.0 to 45 % by weight. Such micellar solutions are essentially non-toxic, non-antigenic, non-carcinogenic and the smear layer is completely removed. Further, it has surprisingly been found that such micellar solutions require no further irrigation solutions to prevent endodontic reinfection. Various bacteria are ef fectively removed without the need of hydrogen peroxide .
[0008] In addition, no detrimental precipitates are formed and no dentine discoloration occurs .
[0009] Preferably, the micellar solution is essentially free of hydrogen peroxide , i . e . comprises less than 0 . 01 % by weight hydrogen peroxide and is most preferably completely free of hydrogen peroxide .
[0010] As understood herein, a micellar solution is a dispersion of micelles in water . Micelles are formed due to the presence of the phospholipids , due to their amphiphilic characteristics .
[0011] In preferred embodiments the micel lar solution has a pH between 1 . 5 to 6 . 5 . The carefully selected pH range has the advantage of stabilising the solution, being non-corrosive , non-irritating and still possesses the property of bacterial and biofilm removal and therefore amenable for use as mouth washer and / or antiseptics .
[0012] In further preferred embodiments , the phospholipid is a quaternary ammonium salt , preferably selected from the group consisting of myristamidopropyl PG-dimonium chloride phosphate , linole- amidopropyl PG-dimonium chloride phosphate , cocoamidopropyl PG- dimonium chloride phosphate , sodium coco PG-dimonium chloride phosphate , and combinations thereof . These quaternary ammonium salts , in particular the aforementioned PG-dimonium chloride phosphates , are particularly advantageous due to their foaming behaviour, which can be further enhanced to produce microstreaming, for example through ultrasonic agitation . Further, they reduce the surface tension, which allows the micellar solution to reach even the smallest side channels of the root canal to remove the biofilm and avoid reinfections . In addition, they aid in the incorporation of di f ficult to dissolve chemical substances present in the irrigation solution . This prevents phase separation and provides a physically stable micellar solution . Moreover, they make the solution mild and non-corrosive . As a result , the periodontal tissue is not damaged .
[0013] Myristamidopropyl PG-dimonium chloride phosphate , which is particularly preferred, is also referred to as [ 3-bis [ 3- [ dimethyl- [ 3- ( tetrade canoyl amino ) propyl ] azaniumyl ] - 2 -hydroxypropoxy ] phosphor yloxy- 2 -hydroxypropyl ] -dimethyl- [ 3- ( tetrade canoylamino ) propyl ] azanium; trichloride . In particular in the preferred concentration range ( cf . below) , it completely, ef fectively and gently removes the biofilm without irritating the soft tissue . It further provides advantageous viscosity and good surface tension reduction, allowing the micellar solution to penetrate deeper into the accessory canals , lateral canal , and isthmus .
[0014] In further preferred embodiments , the phospholipid ( s ) is / are comprised in a concentration between 0 . 01 - 30% by weight , preferably in a concentration between 0 . 1 - 15% by weight , more preferably in a concentration of about 2 . 5 % . In this range of concentrations , the physical and functional integrity of the solution is not compromised, which could otherwise render the solution unusable for its intended application .
[0015] In further preferred embodiments , the chelating agent ( s ) is / are selected from the group consisting of glycolic acid; lactic acid; gluconic acid; carboxylic acids with two or more carboxylic acid groups , in particular a tricarboxylic acid, preferably citric acid; N- ( 2-hydroxyethyl ) iminodiacetic acid (HEIDA) ; aminopolycarboxlic acids , preferably ethylenediaminetetraacetic acid (EDTA) ; hydroxyethylethylenediaminetriacetic acid (HEDTA) ; methylglycinediacetic acid (MGDA; , L-glutamic acid, N, N-diace- tic acid ( GLDA) ; and combinations and salts thereof . Citric acid ( and its salts , respectively) is particularly preferred because it very ef fectively destroys the smear layer and does not lead to undesirable precipitations . In addition, citric acid is low in toxicity . Aminopolycarboxlic acids , preferably ethylenediaminetetraacetic acid (EDTA) ( and salts thereof , respectively) , are advantageous because they show a microbial ef fect that avoids reinfections of the endodontic area .
[0016] In further preferred embodiments , the chelating agent ( s ) , preferably the tricarboxylic acid or a salt thereof , is / are comprised in a concentration between 5 to 25% by weight , more preferably in a concentration of about 10% by weight . It has been found that this range of concentrations is advantageous for effective removal of the smear layer without compromising the integrity of the dentine . For example , higher concentrations were found to cause demineralisation of the dentin, resulting in microcracks and tooth fracture over time .
[0017] In further preferred embodiments , the chelating agent ( s ) is / are selected from the group consisting of ethylenediaminetetraacetic acid (EDTA) and citric acid and a combination thereof . In these embodiments , it is preferred that the ethylenediamintetraacetat and / or citric acid or the salt thereof is comprised in the micellar solution in a concentration between 1 - 25% by weight , preferably in a concentration between 5 - 20% by weight , more preferably in a concentration of about 17 % by weight .
[0018] In some embodiments , the micellar solution further comprises a surfactant which is not a phospholipid . In preferred embodiments, the surfactant that is not a phospholipid is comprised in the micellar solution in a concentration between 0.01 - 15.0% by weight, preferably in a concentration between 0.1 - 10.0% by weight, more preferably in a concentration of about 0.65 % by weight.
[0019] In preferred embodiments, the surfactant that is not a phospholipid is polyglycerol; or an ester of polyglycerol and caprylic acid. A preferred surfactant that is not a phospholipid is poly- glyceryl-10 caprylate. Polyglyceryl-10 Caprylate, in particular in the aforementioned concentration ranges, is mild and shows excellent foaming properties. It aids in creating a flash foam and supports a more stable foam structure for the micellar solution. Further, and in particular in the aforementioned concentration ranges, the surface tension and viscosity of the solution allow for a better flow so that necrotic tissues and dentinal debris are better removed from the canal ramification.
[0020] In preferred embodiments, the micellar solution further comprises a preservative, to increase the lifetime of the micellar solution .
[0021] In further preferred embodiments, the preservative is comprised in a concentration between 0.01 - 2.0% by weight, preferably in a concentration between 0.1 - 1.5% by weight, more preferably in a concentration of about 1.0% by weight.
[0022] In further preferred embodiments, the preservative is 2-phenoxy- ethanol. It has been found to very effectively preserve the solution from degradation and to prolong the shelf life. In addition, it enhances the antimicrobial properties of the solution. In the following the invention is exemplified in more detail with specific examples, without restricting the object of the invention to these embodiments.
[0023] The composition of a micellar solution according to the specific example is as follows (amounts are given in % by weight) :
[0024] Component %
[0025] Myristamidopropyl PG-dimonium chloride phosphate (phospholipid) 2.5
[0026] Citric acid (chelating agent) 6.80
[0027] Tri-sodium citrate dihydrate (chelating agent) 3.30
[0028] 2-Phenoxyethanol (preservative) 1.00
[0029] Polyglyceryl-10 caprylate (surfactant) 0.65
[0030] Distilled water (matrix) 85.75
[0031] Figure 1: Scanning electron microscope (SEM) images showing the effect of the exemplary micellar solution on a human dentine disc-surface
[0032] As shown in Fig. 1, the effect of an exemplary micellar solution on the smear layer is striking.
[0033] The smear layer removal was evaluated by soaking dentine discs in the micellar solution for 5 min. Afterwards the dentine discs were analysed by scanning electron microscope (SEM) . The dentine discs were obtained by sectioning human teeth horizontally with a disc size of 2mm. The discs were rinsed with deionised water and dried with filter paper. An initial scanning electron microscope analysis has been performed. After soaking the dentine discs of 5 minutes in the micellar solution, the dentine discs were rinsed again with deionised water to terminate further chemical activity of the solution on the dentine discs. The dentine discs were dried again with filter paper. Finally, a scanning electron microscope analysis (SEM) was carried out. The result of the SEM shows that the smear layer covering the canal surfaces after sectioning of the teeth were signi ficantly removed after treating the dentine discs with the exemplary micellar solution . The dentine tubuli are clearly visible .
[0034] The smear layer removal was further analysed by EDX ( energy dispersive X-ray spectroscopy, Hitachi TM 4000 Plus I I with EDX Detector Oxford Xplore Compact 30 , 2500 times magni fication, 15 kV accelerating voltage ) and are summari zed in table 1 .
[0035] Table 1 : EDX analysis before and after treatment with the solution according to the invention :
[0036] As can be seen in table 1 , the amount of calcium and phosphor, being elements of the dentine , is reduced . This is due to that the smear layer comprises dentine material that blocks the dentine tubules . For an ef ficient disinfection, this dentine material has to be removed so that the solution can act on the small dentine tubules of the dentine . In addition, the biofilm, which is also part of the smear layer, is also removed, in particular indicated by the removal of nitrogen . For comparison, the following composition, based on the disclosure of WO 2021 / 171263, was examined (amounts are given in % by weight) .
[0037] Component %
[0038] Polyaldo 10-1-C 0.65
[0039] Arlasilk-PTM 2.50
[0040] Hydrogen peroxide 0.55
[0041] Citric acid 0.30
[0042] Mandelic acid 0.60
[0043] Benzoic acid 0.25
[0044] 2-Phenoxyethanol 2.00
[0045] Sodium citrate dihydrate 0.05
[0046] Benzotriazole 0.15
[0047] Distilled water 92.95
[0048] Figure 2: Scanning electron microscope (SEM) images showing the effect of the comparison solution on a human dentine disc-surface
[0049] As shown in Fig. 2, the effect of the comparison solution on the smear layer is less striking. In fact, the smear layer is rather insufficiently removed. The dentine tubules are not visible. The result has also been confirmed by EDX analysis. As can be seen from table 2, the amounts of calcium and phosphor are only reduced by an insignificant amount.
[0050] Table 2: EDX analysis before and after treatment with the comparison solution:
[0051] Antimicrobial test
[0052] Both solutions , the micellar solution according to the invention and the comparison solution have similar ef fects on bacterial removal . In addition, the micellar solution according to the invention ef fectively removes gram-positive and gram-negative bacteria . The results are provided in table 3 .
[0053] The antimicrobial tests were conducted as follows :
[0054] 1 g of the micellar solution ( or the comparison) , which is usually the amount for application to the human skin, was contaminated with 1 x 106bacteria, which refers to the number of germs on the human skin . The mixture of bacteria and micellar solution was incubated at room temperature and directly ( to ) and after a certain time interval ( tsmin) examined .
[0055] For examination, an aliquot of the mixture was diluted with a neutralisation medium ( 30 g / L Polysorbat 80 , 30 g / L Saponin, 3 g / L Lecithin) 1 : 10 , thoroughly mixed and plated on agar plates , which were then incubated for 24 hours at 37 ° C .
[0056] The colony- forming units were counted the next day . Based on these values , the short-term antimicrobial activity of a sample compared to a blank can be determined . The reduction of bacteria concentration can be provided in percentage or Log scale . Most bacteria double all 30 min. Thus, from a single bacterium 1000 bacteria can arise within 5 hours. Therefore, a reduction of 90 % refers to a rather low antimicrobial activity while a good antimicrobial activity can be concluded with a logarithmic reduc- tion of 99.9 % (= 3 logarithmic steps) . All tested samples in table 3 showed a logarithmic reduction of more than 99.9 %.
[0057] Table 3: Effect of the different solutions on different bacteria strains .
Claims
Claims1. A micellar solution for endodontic and / or oral cleaning, in particular for endodontic and / or oral disinfection, comprising- a phospholipid; and- a chelating agent, characterized in that the chelating agent is comprised in a concentration between 5.0 to 45% by weight.
2. A micellar solution according to claim 1, wherein the pH is between 1.5 and 6.5.
3. A micellar solution according to claim 1 or 2 wherein the phospholipid ( s ) is / are a quaternary ammonium salt; preferably selected from the group consisting of myristamidopropyl PG-dimonium chloride phosphate, linoleamidopropyl PG-dimo- nium chloride phosphate, cocoamidopropyl PG-dimonium chloride phosphate, sodium coco PG-dimonium chloride phosphate, and combinations thereof.
4. A micellar solution according to any of claims 1 to 3, wherein the phospholipid ( s ) is / are comprised in a concentration between 0.01 - 30% by weight, preferably in a concentration between 0.1 - 15% by weight, more preferably in a concentration of about 2.5 %.
5. A micellar solution according to any of claims 1 to 4 wherein the chelating agent (s) is / are selected from the group consisting of glycolic acid; lactic acid; gluconic acid; carboxylic acids with two or more carboxylic acid groups, in particular a tricarboxylic acid, preferably citric acid; N- ( 2-hydroxyethyl ) iminodiacetic acid (HEIDA) ;aminopolycarboxlic acids, preferably ethylenediaminetetraacetic acid (EDTA) ; hydroxyethylethylenediaminetriacetic acid (HEDTA) ; methylglycinediacetic acid (MGDA; , L-glutamic acid, N, N-diacetic acid (GLDA) ; and combinations and salts thereof .
6. A micellar solution according to any of claims 1 to 5 wherein the chelating agent (s) , preferably the tricarboxylic acid or a salt thereof, is / are comprised in a concentration between 5 to 25% by weight, more preferably in a concentration of about 10% by weight.
7. A micellar solution according to any of claims 1 to 6 wherein the chelating agent (s) is / are selected from the group consisting of ethylenediaminetetraacetic acid (EDTA) and citric acid and a combination thereof.
8. A micellar solution according to claim 7, wherein the eth- ylenediamintetraacetat and / or citric acid or the salt thereof is comprised in a concentration between 1 - 25% by weight, preferably in a concentration between 5 - 20% by weight, more preferably in a concentration of about 17% by weight .
9. A micellar solution according to any of claims 1 to 8, wherein the micellar solution further comprises a surfactant which is not a phospholipid.
10. A micellar solution according to claim 9, wherein the surfactant is comprised in a concentration between 0.01 - 15.0% by weight, preferably in a concentration between 0.1 - 10.0% by weight, more preferably in a concentration of about 0.65% by weight.
11. A micellar solution according to claim 9 or 10, wherein the surfactant is polyglycerol; or an ester of polyglycerol and caprylic acid.
12. A micellar solution according to any of claims 1 to 11, wherein the micellar solution further comprises a preservative .
13. A micellar solution according to claim 12, wherein the preservative is comprised in a concentration between 0.01 - 2.0% by weight, preferably in a concentration between 0.1 - 1.5% by weight, more preferably in a concentration of about 1.0% by weight .
14. A micellar solution according to claim 12 or 13, wherein the preservative is 2-phenoxyethanol .