Composition of glass ionomer cement with a bioactive substance for dental applications

Abstract

The subject of the invention is a composition of glass ionomer cement with a bioactive substance for dental applications, characterized in that the deposit of the bioactive substance consists of perforated amorphous biosilica.

Description

[0001] The invention relates to a composition of glass ionomer cement with a bioactive substance for dental applications.

[0002] Glass ionomer cement fillings are among the older types of dental restorations, but are still popular in prosthodontics and restorative dentistry. It should be noted that glass ionomer materials have several advantages over modern composite fillings. These advantages include strong adhesion to moist enamel or dentin and caries-inhibiting properties due to their ability to release fluoride. While the materials do not exhibit high fracture, impact, or wear resistance, their clinical durability has been superior to modern composite materials in some cases, e.g.,in relation to the durability of restorations of non-carious cervical lesions (Lohbauer U “Dental Glass Ionomer Cements as Permanent Filling Materials? - Properties, Limitations and Future Trends”, Materials 2009;3(1):76-96) or in restorations placed in primary teeth using the ART approach (Atraumatic Restorative Treatment) (Ersin NK, Candan U, Aykut A, Önçag Ö, Eronat C, Kose T “A clinical evaluation of resin-based composite and glass ionomer cement restorations placed in primary teeth using the ART approach”, The Journal of the American Dental Association 2006;137(11):1529-36). Furthermore, the ATR method has been used in African countries since the 1980s and in Thailand and China since the 1990s (Bąkowicz R, Piatowska D "Conservative treatment of teeth without complete removal of carious dentin", Dent Med Probl. 2008;45(3):314-20). The most commonly used restoration after cavity cleaning is glass ionomer materials.The ideal complement to this approach in restorative dentistry are drug-eluting fillings that support thorough cleaning of the cavity.

[0003] Examples of experimental cements releasing various organic bioactive substances are given in the literature.There are reports of glass ionomer cement releasing chlorhexidine acetate (Palmer G, Jones FH, Billington RW, Pearson GJ ‘Chlorhexidine release from an experimental glass ionomer cement’, Biomaterials 2004;25(23):5423-31) and chlorhexidine hexametaphosphate and chlorhexidine digluconate (Hassan SMA, Kandil MM, El-Refaie D ‘Release characterization and biological effect of Glass Ionomer Functionalized with two different chlorohexidine derivatives: an in vitro study’, RGO - Revista Gaúcha de Odontologia 2022;70), as well as those containing chlorhexidine hexametaphosphate nanoparticles (Hook ER, Owen OJ, Bellis CA, Holder JA, O'Sullivan DJ, Barbour ME ‘Development of a novel antimicrobial-releasing glass ionomer cement functionalized with chlorhexidine hexametaphosphate nanoparticles“, Journal of Nanobiotechnology 2014;12(1)) or chlorhexidine diacetate and antibiotics (ciprofloxycin, metronidazole and minocycline).Glass ionomer compositions containing other antibiotics are also described: doxycycline and its derivative (de Castilho ARF, Duque C, Negrini TdC, Sacono NT, de Paula AB, Sacramento PA, et al. “Mechanical and biological characterisation of resin-modified glass-ionomer cement containing doxycycline hyclate”, Archives of Oral Biology 2012;57(2):131-8), although the latter is released from resin-modified glass ionomer cement. There are also reports of glass ionomer cements releasing ciprofloxycin, metronidazole and minocycline (Celik D, Buruk K, Tasdemir T, Er K, Yesilyurt C “Antibacterial Activity and Physical Properties of Glass-ionomer Cements Containing Antibiotics”, Operative Dentistry 2009;34(1):18-23), or ciprofloxycin and L-carnosine as well as zinc and nanohydroxyapatite (Pagano S, Chieruzzi M, Balloni S, Lombardo G, Torre L, Bodo M, et al."Biological, thermal, and mechanical characterization of modified glass ionomer cements: The role of nanohydroxyapatite, ciprofloxacin, and zinc L-carnosine," Materials Science and Engineering: C 2019;94:76-85). Clinical trials with glass ionomer materials containing antibiotics (metronisadol, ciprofloxacin, and cefaclor) have proven satisfactory in dentistry for the restorative treatment of primary teeth (Ferreira JMS, Pinheiro SL, Sampaio FC, Menezes VAd "Use of glass ionomer cement containing antibiotics to seal off infected dentin: a randomized clinical trial," Brazilian Dental Journal 2013;24(1):68-73).Although it has been possible to improve the antibacterial activity of materials filled with bioactive substances, this is accompanied by a deterioration in the physico-mechanical properties of modified glass ionomer cements (Ching HS, Luddin N, Kannan TP, Ab Rahman I, Abdul Ghani NRN 'Modification of glass ionomer cements on their physicalmechanical and antimicrobial properties', Journal of Esthetic and Restorative Dentistry 2018;30(6):557-71).

[0004] An interesting ingredient that improves some physico-mechanical parameters is diatomaceous earth, the addition of which increases the microhardness of glass ionomer cement (Łępicka M, Rodziewicz M, Kawalec M, Nowicka K, Tsybrii Y, Kurzydłowski KJ "Diatomaceous earth as a drug-loaded carrier in a glass-ionomer cement," Journal of the Mechanical Behavior of Biomedical Materials 2022;133). Furthermore, diatomaceous earth has many potential uses, for example, as a drug-loaded carrier, as described in patent application US2013149380A1, which presents an invention for solid pharmaceutical preparations containing, in addition to the active ingredient, diatomaceous earth (diatomite) or natural mineral mixtures with diatomaceous earth and other excipients.

[0005] However, diatomaceous earth has several disadvantages for the release of bioactive substances in (bio)medical applications. These include the impact on the heterogeneity of the material properties, as diatomaceous earth consists of a mixture of diatom shells of various types, shapes, and sizes. Another disadvantage is purity; diatomaceous earth is a natural mineral that may contain other minerals or organic substances. Controlling the release of diatomaceous earth as a carrier of bioactive substances can be more difficult due to the heterogeneity of the material. Diatomaceous earth is also more difficult to functionalize due to its heterogeneity.

[0006] In contrast, diatom shells do not have these disadvantages and can be supplied as a much more homogeneous material.

[0007] Given the disadvantages associated with the use of diatomaceous earth, the use of diatom shells for controlled drug delivery has increased significantly in recent decades - thanks to their unique properties.

[0008] Initial research on the use of diatom shells without surface modification for drug delivery, conducted since 2010, focused mainly on the encapsulation of therapeutic molecules for oral drug delivery.

[0009] Losic et al. investigated the use of microscopic diatom coatings for the delivery of the hydrophobic molecule indomethacin and demonstrated the high potential and efficacy of diatom shells with a drug loading of approximately 22%.

[0010] Zhang et al. investigated the ability of diatom shells to release mesalamine and prednisone under conditions mimicking the gastrointestinal tract. The results demonstrated controlled and sustained release of both drugs. Chemical modification of the surface of diatom shells enables improved drug loading and release, as well as surface functionalization with organic, inorganic, and biomolecules.

[0011] Milović and colleagues described the use of diatom shells as a solid carrier for the drug carbamazepine in an oral delivery system based on a self-emulsifying delivery system.

[0012] Vasani et al. demonstrated the controlled release of the antimicrobial drug levofloxacin from modified diatom microcapsules grafted with thermosensitive oligo(ethylene glycol) methacrylate copolymers.

[0013] It has been demonstrated that diatom shells can be used as a cost-effective source for the scalable production of drug carriers enabling controlled therapeutic delivery (Terracciano M, De Stefano L, Rea I, 'Diatoms Green Nanotechnology for Biosilica-Based Drug Delivery Systems', Pharmaceutics 2018;10(4)).

[0014] The core of the invention is a composition of glass ionomer cement with a bioactive substance for dental applications, characterized in that the deposit of the bioactive substance consists of perforated amorphous biosilica.

[0015] It is preferred that the concentration of the deposit of the bioactive substance is up to 10 wt%.

[0016] It is preferred to use the composition according to claim 2, characterized in that the concentration of the deposit of the bioactive substance is between 3 wt% and 6 wt%.

[0017] It is preferred to use the composition according to claim 1 or 2, characterized in that the concentration of the bioactive substance in the deposit is up to 10 wt.%.

[0018] The composition according to claim 1 or 2 or 4 is preferred, characterized in that the bioactive substance is an antibiotic.

[0019] The composition according to claim 5 is preferred, characterized in that the antibiotic is a β-lactam antibiotic. The composition according to claim 6 is preferred, characterized in that the β-lactam antibiotic is amoxicillin.

[0020] The composition according to claim 1 is preferred, characterized in that the biosilica is of natural origin.

[0021] Unexpectedly, it turned out that the use of deposits of a bioactive substance (drug, antibiotic) on diatom shells - perforated amorphous biosilica obtained from renewable sources - improves certain performance parameters of glass ionomer cements (e.g., resistance to acid erosion), does not affect the other parameters of the product and, what is especially important, provides effective, prolonged release of the active form of the deposited substance for at least 14 days. Fig. Figure 1 shows the surface microhardness of glass ionomer cement samples. Fig. Figure 2 shows the average values ​​of cavity depth after 1 day of conditioning in erosion solution. Fig. Figure 3 shows the average values ​​of cavity depth after 7 days of conditioning in erosion solution. Examples of implementationExample 1.

[0022] Three variants of a commercially available glass ionomer cement (3M Ketac Universal; consisting of a solid (powder) phase: glass, oxides, chemicals (95%); and a liquid phase: maleic acid-acrylic acid copolymer (30-50%); tartaric acid (1-10%); benzoic acid (<0.2%)) were prepared for dental applications with additives: (i) 5 wt% purified diatom shells of the strain Pseudostaurosira trainorii; (ii) 5 wt% diatom shells of the strain Pseudostaurosira trainorii loaded with an antibiotic (amoxicillin) at 9.3 wt%; (iii) an antibiotic (amoxicillin) in pure form at 0.5% w / w.

[0023] The diatom shells were freed from organic material by chemical oxidation: (a) A sample containing diatom shells was transferred into a test tube. (b) An appropriate amount of hydrogen peroxide (H2O2 30%) was added to the sample in a volume ratio of 1:1 (1 ml H2O2 per 1 ml sample), although this ratio can be adjusted depending on the organic phase content of the sample. (c) The sample was stirred gently between 100-300 rpm to ensure uniform distribution of H2O2. (d) The sample was heated in a water bath (at 75°C) for 4 hours.) (e) After completion of the reaction, the sample was cooled to room temperature. (f) The supernatant (topmost liquid layer) was removed and distilled water was added to wash the diatom shells. (h) Step (f) was repeated until the water was clear, indicating the removal of H2O2 and organic material.

[0024] To prepare the samples, a fixed amount of both glass ionomer phases (liquid and powder; in a ratio of 2:1) was mixed by hand with the corresponding additive (i-iii) until complete agglutination was achieved and then filled into molds (disks 15 mm in diameter and 2 mm high). The unaltered product served as the reference material. The time from contact between the two phases to filling into the mold did not exceed 180 s. After filling the molds and curing, the samples were incubated in deionized water at 37 °C for 1 day. Subsequently, the microhardness was measured using a microhardness meter (MicVision VH-1). Ten measurements were performed for each sample type.

[0025] The measurement results showed that the addition of the drug depot did not change the microhardness of the glass ionomer cement, whereas the addition of the drug in pure form statistically significantly reduced the microhardness of the material. Furthermore, the median microhardness measurements were higher for the material with drug-loaded diatom shells than for the material with pure shells. Example 2.

[0026] Three variants of two commercially available glass ionomer cements were prepared: Cement 1 (3M Ketac Molar Easymix, consisting of solid phase (powder): glass powder (85-95%) and polyacrylic acid (5-15%); and liquid phase: maleic acid-acrylic acid copolymer (25-40%); tartaric acid (5-10%)) and Cement 2 (3M Ketac Universal; consisting of solid phase (powder): glass, oxides, chemicals (95%); and liquid phase: maleic acid-acrylic acid copolymer (30-50%); tartaric acid (1-10%); benzoic acid (<0.2%)) for dental applications with additives: (i) 5 wt% purified diatom shells of the strain Pseudostaurosira trainorii; (ii) 5 wt% diatom shell strain Pseudostaurosira trainorii loaded with an antibiotic (amoxicillin) at 9.3 wt%; (iii) an antibiotic (amoxicillin) in pure form at 0.5% w / w.

[0027] The diatom shells were freed from organic material by chemical oxidation: (a) A sample containing diatom shells was transferred into a test tube. (b) An appropriate amount of hydrogen peroxide (H2O2 30%) was added to the sample in a volume ratio of 1:1 (1 ml H2O2 per 1 ml sample), which can be adjusted depending on the content of the organic phase of the sample. (c) The sample was stirred gently between 100-300 rpm to ensure uniform distribution of H2O2. (d) The sample was heated in a water bath (at 75°C) for 4 hours.) (e) After completion of the reaction, the sample was cooled to room temperature. (f) The supernatant (topmost liquid layer) was removed and distilled water was added to wash the diatom shells. (h) Step (f) was repeated until the water was clear, indicating the removal of H2O2 and organic material.

[0028] To prepare the samples, a fixed amount of the two glass ionomer phases (liquid and powder; in a ratio of 3.1:1 for cement 1 (3M Ketac Molar Easymix) and 2:1 for cement 2 (3M Ketac Universal)) was mixed by hand with the corresponding additive (i-iii) until complete agglutination was achieved and then filled into molds (disks with a diameter of 15 mm and a height of 2 mm). The unaltered product served as the reference material. The time from contact between the two phases to filling into the mold did not exceed 180 s.

[0029] The acid erosion resistance tests were carried out according to ISO 9917-1 over an extended period of up to 7 days.

[0030] For cement 1, an improvement in acid erosion resistance was observed for materials containing the drug depot and the drug in pure form after both 1 and 7 days. Example 3.

[0031] Two variants of two commercially available glass ionomer cements were produced: Cement 1 (3M Ketac Molar Easymix, consisting of solid phase (powder): glass powder (85-95%) and polyacrylic acid (5-15%); and liquid phase: maleic acid-acrylic acid copolymer (25-40%); tartaric acid (5-10%)) and Cement 2 (3M Ketac Universal; consisting of solid phase (powder): glass, oxides, chemicals (95%); and liquid phase: maleic acid-acrylic acid copolymer (30-50%); tartaric acid (1-10%); benzoic acid (<0.2%)) for dental applications with additives: (i) 5 wt% purified diatom shells of the strain Pseudostaurosira trainorii loaded with an antibiotic (amoxicillin) at 9.3 wt%; (ii) 5% by weight of the shell of the strain Pseudostaurosira trainorii and the antibiotic (amoxicillin) in pure form at 0.5% by weight.

[0032] The diatom shells were freed from organic material by chemical oxidation: (a) A sample containing diatom shells was transferred into a test tube. (b) An appropriate amount of hydrogen peroxide (H2O2 30%) was added to the sample in a volume ratio of 1:1 (1 ml HO 22 per 1 ml of sample), whereby this ratio can be adjusted depending on the content of the organic phase of the sample. (c) The sample was stirred gently between 100-300 rpm to ensure uniform distribution of H2O2. (d) The sample was heated in a water bath (at 75°C) for 4 hours.) (e) After completion of the reaction, the sample was cooled to room temperature. (f) The supernatant (topmost liquid layer) was removed and distilled water was added to wash the diatom shells. (h) Step (f) was repeated until the water was clear, indicating the removal of H2O2 and organic material.

[0033] To prepare the samples, a predetermined amount of the two glass ionomer phases (liquid and powder; in a ratio of 3.1:1 for cement 1 and 2:1 for cement 2) was mixed by hand with the corresponding additive (i-iii) until completely clumped and then filled into molds (disks 15 mm in diameter and 2 mm high). The samples were then placed in 10 ml of deionized water and incubated at 37°C. Every 24 hours, the samples were transferred to a new aliquot of deionized water. The amount of released drug was determined by high-performance chromatography (HPLC) in the medium after incubation of the samples (selected data).

[0034] The results show that the active ingredient is released. This release occurs throughout the entire study period. Time [days]. Approved drug Cement 1 Cement 2 Drug deposit [µg / ml] unbound drug [µg / ml] Drug deposit [µg / ml] unbound drug [µg / ml] 1 4,08 ± 0,22 4,34 ± 0,22 4,32 ±0,26 4,58 ± 0,18 4 3,14 ± 0,10 3,06 ± 0,10 4,14 ± 0,12 4,46 ± 0,10 7 2,04 ± 0,08 3,16 ± 0,06 3,28 ± 0,04 3,42 ± 0,22 10 2,16 ± 0,12 2,14 ± 0,10 2,06 ± 0,14 3,32 ± 0,12

[0035] It should be noted that diatom shells obtained from natural sources may contain impurities of organic origin; therefore, for biomedical applications, the material is purified of organic residues. Furthermore, the use of diatom shells from a single species can allow for finer tuning of release rate and profile. Diatom shells also allow for easier surface modification for functionalization, which is important for many applications such as combination with proteins, drugs, or other bioactive substances. Furthermore, diatom shells from cultured diatoms can be genetically modified to produce shells with desired properties. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2013149380A1

[0004] Cited non-patent literature

[0000] Lohbauer U “Dental Glass Ionomer Cements as Permanent Filling Materials? - Properties, Limitations and Future Trends”, Materials 2009;3(1):76-96

[0002] Ersin NK, Candan U, Aykut A, Önçag Ö, Eronat C, Kose T “A clinical evaluation of resin-based composite and glass ionomer cement restorations placed in primary teeth using the ART approach”, The Journal of the American Dental Association 2006;137(11):1529-36

[0002] Bąkowicz R, Piatowska D „Conservative treatment of teeth without complete removal of carious dentin“, Dent Med Probl. 2008;45(3):314-20

[0002] Palmer G, Jones FH, Billington RW, Pearson GJ ‚Chlorhexidine release from an experimental glass ionomer cement‘, Biomaterials 2004;25(23):5423-31

[0003] Hassan SMA, Kandil MM, El-Refaie D 'Release characterization and biological effect of Glass Ionomer Functionalized with two different chlorohexidine derivatives: an in vitro study", RGO - Revista Gaúcha de Odontologia 2022;70

[0003] Hook ER, Owen OJ, Bellis CA, Holder JA, O'Sullivan DJ, Barbour ME „Development of a novel antimicrobial-releasing glass ionomer cement functionalized with chlorhexidine hexametaphosphate nanoparticles“, Journal of Nanobiotechnology 2014;12(1

[0003] de Castilho ARF, Duque C, Negrini TdC, Sacono NT, de Paula AB, Sacramento PA, et al. „Mechanical and biological characterisation of resin-modified glass-ionomer cement containing doxycycline hyclate“, Archives of Oral Biology 2012;57(2):131-8

[0003] Celik D, Buruk K, Tasdemir T, Er K, Yesilyurt C „Antibacterial Activity and Physical Properties of Glass-ionomer Cements Containing Antibiotics“, Operative Dentistry 2009;34(1):18-23

[0003] Pagano S, Chieruzzi M, Balloni S, Lombardo G, Torre L, Bodo M, et al. „Biologische, thermische und mechanische Charakterisierung von modifizierten Glasionomerzementen: Die Rolle von Nanohydroxyapatit, Ciprofloxacin und Zink-L-Carnosin“, Materials Science and Engineering: C 2019;94:76-85

[0003] Ferreira JMS, Pinheiro SL, Sampaio FC, Menezes VAd „Use of glass ionomer cement containing antibiotics to seal off infected dentin: a randomised clinical trial“, Brazilian Dental Journal 2013;24(1):68-73

[0003] Ching HS, Luddin N, Kannan TP, Ab Rahman I, Abdul Ghani NRN ‚Modification of glass ionomer cements on their physicalmechanical and antimicrobial properties‘, Journal of Esthetic and Restorative Dentistry 2018;30(6):557-71

[0003] Łępicka M, Rodziewicz M, Kawalec M, Nowicka K, Tsybrii Y, Kurzydłowski KJ „Diatomaceous earth as a drug-loaded carrier in a glass-ionomer cement“, Journal of the Mechanical Behavior of Biomedical Materials 2022;133

[0004] Terracciano M, De Stefano L, Rea I, ‚Diatoms Green Nanotechnology for Biosilica-Based Drug Delivery Systems‘, Pharmaceutics 2018;10(4

[0013]

Claims

[1] Composition of glass ionomer cement with a bioactive substance for dental applications, characterized by that the deposit of the bioactive substance consists of perforated amorphous biosilica. [2] The composition according to claim 1, characterized by that the concentration of the bioactive substance deposit is up to 10 wt.%. [3] The composition according to claim 2, characterized by that the concentration of the deposit of the bioactive substance is between 3 wt% and 6 wt%. [4] The composition according to claim 1 or 2, characterized by that the concentration of the bioactive substance in the deposit is up to 10 wt.%. [5] The composition according to claim 1 or 2 or 4, characterized by that the bioactive substance is an antibiotic. [6] The composition according to claim 5, characterized by that the antibiotic is a β-lactam antibiotic. [7] The composition according to claim 6, characterized by that the β-lactam antibiotic is amoxicillin. [8] The composition according to claim 1, characterized by that the biosilica is of natural origin.

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