WO2023163676A1 - Production of antibacterial and regenerative dental composites using supportive phases with improved antibacterial and bioactive properties - Google Patents

Abstract

The present invention relates to light curable and polymerizable acrylic dental composite fillings for restorative purposes and to the production of the said dental composites. Dental composites are mainly composed of a supportive phase consisting of ceramic-based materials and a polymer-based organic resin. In addition to the supportive phase structures, a composite material may comprise various structures called binding agents, which provide chemical bonding between the supportive phase and the organic phase, allowing the service life as well as the mechanical, chemical, and physical properties of the composite material to be improved.

Description

PRODUCTION OF ANTIBACTERIAL AND REGENERATIVE DENTAL COMPOSITES USING SUPPORTIVE PHASES WITH IMPROVED ANTIBACTERIAL AND BIOACTIVE PROPERTIES

TECHNICAL FIELD

The present invention relates to light curable and polymerizable acrylic dental composite fillings for restorative purposes and to the production of the said dental composites. Dental composites are mainly composed of a supportive phase consisting of ceramic-based materials and a polymer-based organic resin. In addition to the supportive phase structures, a composite material may also comprise various structures called binding agents, which provide chemical bonding between the supportive phase and the organic phase, allowing the service life as well as the mechanical, chemical, and physical properties of the composite material to be improved.

BACKGROUND

Resin-based composite (RBC) materials were first reported by Bowen in 1958. However, commercial use of resin-based composites was only possible after the author was granted the patent named "A vinyl-silane treated fused silica and binder" in 1962. Chemically cured RBCs became a concept only in 1970 when they were introduced to the dental market. On the other hand, although abrasive-free applications in large-scale restorations are limited, these materials have been frequently preferred in Class I and Class II restorations.

The patenting of "A method of repairing teeth using a composition which was curable by visible light" by Dart in 1974 and the development of "total-etch" adhesives in the 1980s paved the way for these materials by supporting the clinical use of light-cured RBCs in Class I and Class II restorations.

In recent years, due to the increasing expectations in aesthetic dentistry, the development of clinically long-lasting resin composites with advanced physical and mechanical properties that meet aesthetic requirements for use in direct restorations has become inevitable. One of the most important developments in this field is the use of nanostructured particles combined with nano-crystals in the structure of traditional resins. The history of existing resin monomers dates back to the discovery of a new acid called "acrylic acid" by a German chemist named J. Redtenbacher. By the 1900s, methacrylic acid and many ester derivatives were synthesized, as well as methyl methacrylate polymers were produced by polymerization technique. In the late 1930s, polymethyl methacrylate entered the field of dentistry for the first time as prosthetic base resins and a few years later it was used as indirect filling material. With the discovery of benzoyl peroxide-tertiary amine redox initiator-accelerator systems in Germany during World War II, the polymerization of methyl methacrylate could be carried out at room temperature, thus enabling the use of these polymeric structures as direct filling materials. However, these materials have failed to meet the required clinical expectations.

Observing the inadequate properties of methyl methacrylate resins, American dentist R. L. Bowen developed other synthetic resins for use in dental filling materials. In this context, he conducted studies on epoxy resins that can polymerize at room temperature. Although epoxy resins exhibited good aesthetic properties in the oral cavity, the slow curing stage prevented their direct use as filling materials.

Due to the problems encountered in epoxy resins, Bowen conducted studies on a new monomer system, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane-BisGMA structure in 1956. This monomer system was found to have superior properties compared to methyl methacrylate systems due to its high molecular weight, chemical structure, low volatility, low polymerization shrinkage, and fast curing properties.

BisGMA has found wide use in commercial dental resin composites. However, the monomer has poor color stability, is highly viscous, and cannot be purified by distillation and crystallization. In order to overcome this problem, Bowen studied a new monomer system, isomeric crystalline dimethacrylates, which are liquid and exhibit eutectic formations at room temperature. In this context, he synthesized three aromatic diesters of phthalic (P), isophthalic (I), and terephthalic (T) acids; bis(2-methacryloxyethyl)-P/l/T ester monomer and purified it by recrystallization method. It was determined that the mechanical properties of the composites produced from these monomers were equivalent to BisGMA and the polymerization shrinkage values met the expected properties. However, these monomer systems could not provide the expected color stability under in vivo conditions.

Due to their polar structure, dimethacrylate resins tend to adsorb water in the oral environment and exhibit hygroscopic expansion. Although this expansion has some advantages, it causes various disadvantages such as decreased mechanical strength and abrasion resistance in the long term. For this reason, hydrophobic monomer systems obtained by removing the hydroxyl groups in BisGMA chains have been developed to minimize the water retention capacity of the resin. However, these systems also failed to meet the desired mechanical properties.

Since the expected properties of hydrophobic monomers are not met, various studies have been carried out to develop fluorocarbon-containing polymers with low surface energy and high hydrophobic properties. In this context, polyfluoro monomethacrylate and octofluoropentyl methacrylate monomer systems were used in resin composites. Although these composite structures provided the expected hydrophobic properties against water, they could not provide sufficient physical and mechanical properties as well as exhibiting very high polymerization shrinkage.

Urethane dimethacrylates (UDM), another monomer system used in composite resins, were first synthesized from hydroxyalkyl methacrylates and diisocyanates. This monomer has a similar molecular weight to BisGMA, but a lower viscosity. The higher monomer conversion percentage of composite systems produced using UDM monomers compared to BisGMA systems provides higher biocompatibility. Due to their cost-effectiveness, these systems can be used as an alternative to BisGMA monomer in commercial resin composites.

Polymerization shrinkage is the most common problem in composite resins. The approximate volume shrinkage of BisGMA-based polymers is around 5% and this value can be reduced by increasing the loading of the supportive phase systems. Since polymerization shrinkage is one of the important parameters affecting the lifetime of the composite, various studies have been carried out on bicyclic compounds that do not show shrinkage and polymerize by the ring-opening polymerization technique. Bailey stated that various bicyclic monomers including spiro orthoesters, spiro orthocarbonates, bicyclo keto lactones, and trioxabicyclo octanes and unsaturated diketals exhibited double ring opening polymerization without shrinkage and/or expansion. However, at the end of the reaction, it was determined that there was a lot of monomer remaining in the environment that was not incorporated into the polymeric structure.

Developments in organic resin structure were followed in 1994 by the production of composites modified with polyacids, known as "compomers". These composite materials are obtained by embedding supportive phase systems such as calcium-aluminum- fluorosilicate glasses into the polymer resin. Compomers are dental materials that combine the aesthetic properties of traditional composites with the fluoride release and adhesion properties of glass ionomer cements. However, compomers differ from glass ionomer cements in two ways: firstly, the glass particles are partially silanized to ensure bonding with the resin, and secondly, the polymeric structure is formed by radical polymerization reactions following light activation of the monomers.

In 1984, Schmidt synthesized organic-inorganic polymeric hybrid structures, first called "ormosils (organically modified silicates)" and later "ormocers (organically modified ceramics)". In ormocers, organic and inorganic compounds interact on a nanoscopic, in other words, molecular scale. For this reason, these materials have the properties of organic and inorganic components in their structure but exhibit unique properties whose cause is not yet understood. The use of ormocers in dentistry started in 1998 and especially in recent years, ormocers have found commercial use in restorative material applications.

One of the technological developments of recent years in dental commercial materials is the use of silorane-based organic resin monomers. Silorane monomer takes its name from the siloxane and oxirane molecules that make up its structure. Silorane monomers, which are predicted to be an alternative to methacrylate-based monomers and developed within 3M ESPE in order to obtain composite materials that reduce polymerization shrinkage and maintain appropriate mechanical strength, have been able to find commercial application in a short time due to meeting the desired clinical expectations.

In addition to reducing the polymerization shrinkage, another feature desired to be added to the monomer systems is the antibacterial effect. In this context, monomers exhibiting antibacterial properties were produced instead of adding fluoride-releasing compounds to the structure. The most promising monomer in this context is methacrylyl- dodecylpyridinium bromide (MDPB) produced by the reaction of the antibacterial agent dodecylpyridinium bromide and methacrylic group. In various studies, it has been determined that composite systems produced by copolymerization of methacrylyl- dodecylpyridinium (MDP) with traditional dental monomers have an inhibitory effect on bacterial growth on the surface. However, in today's commercially produced composite systems, the antibacterial effect is realized through supportive phase particles that release fluoride rather than through such monomer systems.

In the 1960s, three basic materials were used in the structure of the first composite resin: monomer, silane-treated supportive phase, and initiator. The supportive phase used by Bowen in 1963 consisted of ground quartz particles with an average size of 8-12 pm (8000-12000 nm). Due to the limitations of macrofill composites in aesthetic restorations (such as problems with surface polishing), minifill composites were developed in the 1970s. Supportive phase systems produced by pyrogenic methods allowed a maximum loading of 55% of the composites, increasing polishability but significantly reducing mechanical strength.

It was only in the 1980s and 1990s that supportive phase systems were tested as mixtures. Restorative materials comprising these hybrid supportive phase systems with particle sizes of 600-2,000 nm were commercialized as hybrid, microhybrid, and densified (whisker structure) composites. Although the mechanical strength has been significantly increased with these products, the polishability is still limited. The maximum loading rate in these products has reached values of 70-77 wt%. Nevertheless, the particle size values of conventional composites could not provide sufficient compatibility with the hydroxyapatite crystals, dentin tubules, and enamel rods in the natural structure of the tooth. Therefore, the potential to provide the necessary adhesion between the macroscopic restorative material and the nanoscopic (1-10 nm) tooth structure could not be achieved.

Since it is not possible to produce supportive phases below 100 nm by grinding, the use of nanotechnological methods in the production of supportive phases has been an innovative technique in this field, providing controlled crystal growth and structural and dimensional homogeneity of the final product. At the beginning of the current century, Filtek Supreme (3MESPE, St. Paul, USA) became the commercial milestone of nanotechnology applications in operative dentistry. The composite resin produced in this context consists of 78.5 wt% of aggregated zirconia/silica clusters with a primary particle size of 5-20 nm and a silica-based supportive phase system with a particle size of 20 nm with no aggregation.

In recent years, composite systems comprising microhybrid and nanofilament composites have been commercialized. This new composition has enabled the loading ratios of the supportive phase systems to be increased up to 87 wt% due to the formation of filler voids between larger particles and smaller particles.

Depending on the development of supportive phase and monomer systems, the curing techniques used for the polymerization of composites have also evolved over time. As mentioned earlier, the first composite filling materials used in dentistry were polymerized by redox reactions at room temperature. The polymerization reactions of these products, which were packaged as two separate materials, started with the mixing of the products and required a long period of 8 minutes to complete the polymerization properly.

Due to the long polymerization time, photopolymerizable composite systems (Nuva; Dentsplay/Caulk) were developed in the late 1970s. This type of polymerization method gave the dentist the advantage of being able to cure and contour the product quickly after placement. In the early days, quartz lamps with a wavelength of 354 nm were used as a UV light source, and the polymerization reaction was based on free radical formation. Although this system was advantageous at first, various problems such as incomplete polymerization and very rapid depletion of the light source were encountered in the following periods when an intensive application was made. For this reason, visible light energy in the wavelength range of 400-500 nm was started to be applied for photopolymerization in the following periods instead of ultraviolet light. In visible light systems, quartz-tungsten-halogen light sources were first used. The most widely used photoinitiator system in these systems is camphorquinone. With conventional quartz- tungsten-halogen light sources, the polymerization time of a 2 mm thick restoration takes approximately 40-60 seconds. Although these systems are more advantageous for polymerization compared to self-cure systems, the search for new methods has continued because the energy of the light is more intense on the composite surface compared to the underlying regions and the light penetrates the underlying regions with lower intensity.

With the development of laser technologies that provide high light intensity in the energy band range required for photopolymerization in dental materials, dental applications have also improved. The "Argon laser", which provides high energy output at 448 nm wavelength, has provided various advantages such as rapid polymerization in commercial dental restorative materials.

Another system developed to shorten the polymerization time is "Plasma Arc Units". In this context, short arc systems provided by the use of xenon light sources are called plasma arc light sources. This unit consists of spark and fluid gas systems produced by applying high energy potential between two tungsten electrodes. The system operates at a wavelength of 400-500 nm and polymerization takes place in less than 1 second. However, some researchers argue that the properties of the end product will not be of the desired quality due to such a short time of polymerization.

In order to keep quartz-tungsten-halogen lamps on the market, producers have improved the existing system by providing "high energy" output and short application time, similar to plasma arc systems. However, concerns have been raised about polymerization shrinkage due to the development of fast-curing conditions.

Advances in light absorption diode (LED) technology have made the use of these light sources in the dental industry inevitable. The absorption range of blue LED light sources corresponds to the wavelength range of dental photoinitiator systems. The main advantages of this light source are its portability, minimal maintenance, long lifetime, and absorption only at the wavelength required for the activation of the photoinitiator.

Another curing method used especially in cement technologies is the dual-cure method. In the chemical curing method, the excess initiator remaining in the environment must be removed from the environment and the product must be waited for a long time until the product is completely set, so this problem has been tried to be solved with the light curing method. On the other hand, in light curing, complete polymerization cannot be achieved due to the fact that the light is not intense enough in the depths. In order to avoid these problems, dual-cure resin cement systems have been developed by using both chemical and photoinitiator systems in the products.

One of the most important phenomena in composite restorations is the percentage of monomer conversion. One of the simplest methods to achieve polymerization is to apply heat. Heat decreases the monomer viscosity, allowing free radicals to diffuse better into the monomer and a higher monomer conversion percentage is observed. Based on this principle, the "post-cure heating" method has been developed for photoinitiator composite systems. In this method, the composite is first photopolymerized by curing with a conventional light source, and then heat is applied. This method is mostly preferred for glass ionomer systems rather than composite filling materials.

Resin-based composite restorations, which started with methyl methacrylate resin compositions, have progressed considerably in terms of organic resin, inorganic phase, and curing techniques. However, resin-based composite filling materials do not have a structure that can mimic the natural tooth structure and do not have sufficient properties to meet the clinically required expectations. For this reason, research on improving the properties of composite filling materials, taking into account the clinical expectation, continues at an increasing pace.

In 2014, Martin et al. carried out studies on the synthesis of a urethane multimethacrylate- based monomer system that can be an alternative to BisGMA-based composites that cause problems such as low monomer conversion and high volume shrinkage. In this context, they produced urethane-multimethacrylate monomer using methacryloyloxypropylphenylmethane (BMPM) and urethane-methacryloyloxyethyl (UME) starting monomers. By loading silica supportive phase particles into this monomer system, they determined that the composite they produced showed lower polymerization shrinkage and higher bending strength compared to conventional composites and that the physical, chemical and mechanical properties of the composite had a certain balance.

Liu et al. drew attention to the problems of homogeneous distribution of Ag nanocrystals used in dental composites to prevent secondary caries formation in organic resin and loaded silver particles into composite systems by modifying them with organic agents. In this context, he coated Ag nanoparticles with oleic acid and investigated the mechanical and antibacterial properties of dental resin composites. They determined that the modified silver nanoparticles significantly improved the mechanical and antibacterial properties of the composite such as bending strength, modulus of elasticity, and compressive strength compared to unmodified particles.

He et al. carried out studies on the synthesis of antibacterial and radiopaque dimethacrylate monomers for use in dental resin composites. In this context, they synthesized tertiary ammonium dimethacrylate compounds such as N,N-bis[2-(3- (methacryloyloxy)propanamido)ethyl]-N-methyldodecyl ammonium iodide (QADMAI-12), N,N-bis[2-(3-(methacryloyloxy)propanamido)ethyl]-N-methylhexadecyl-ammonium iodide (QADMAI-16) and N,N-bis[2-(3-(methacryloyloxy)propanamido)ethyl]-N-methyloctadestyl ammonium iodide (QADMAI-18). They determined that the antibacterial and radiopacity properties as well as monomer conversion percentages of the produced composites were better compared to conventional composites. However, they observed that the bending strength and modulus of elasticity values of the composites were lower compared to conventional composites.

Liu et al. studied a light-curable biocurable biocative dental resin composite. They combined poly(BisGMA)-graft-silanized whisker hydroxyapatite (PGSHW) and silanized- silica (s-SiOs) nanoparticles and loaded the supportive phase system into bisphenol-A glycidyl methacrylate (BisGMA)/triethylene glycol dimethacrylate (TEGDMA) based dental resin. They determined that the composites comprising PGSHW/s-SiOs hybrid supportive phase system significantly improved the mechanical properties of the material such as bending strength, modulus of elasticity, compressive strength, and toughness as well as monomer conversion percentage values compared to composites comprising hydroxyapatite nanoparticles. They also showed that the composite produced by in vitro bioactivity tests can form apatite.

Wu et al. developed a self-repairing composite comprising dimethylaminohexadodecyl methacrylate (DMAHDM) to provide antibacterial function and nano-sized amorphous calcium phosphate (NACP) for remineralization in order to find solutions to problems such as cracking and secondary caries formation in composite restorations. As a result of their study, they stated that the composite structure produced for the first time in the literature combines crack repair, antibacterial effect, and remineralization ability after crack formation.

Chan et al. conducted studies on composite systems with an antimicrobial effect similar to Wu et al. They loaded nano-sized amorphous calcium phosphate ceramics and dimethylaminododecyl methacrylate (DMADDM) monomeric structures into organic resin systems of conventional composites. As a result of their studies, they determined that Ca and P ion release increased in relation to decreasing pH as a result of bacterial growth, and DMADDM monomer inhibited bacterial growth by showing antimicrobial effect and suggested that these materials may be suitable for use as supportive phase systems in composites.

Similar to Chan et al., Zhang et al. used dimethylaminododecyl methacrylate (DMADDM), amorphous calcium phosphate nanoparticles as well as silver nanoparticles (NAg) as a supportive phase system and found that the antimicrobial effect was longer lasting compared to other composites.

Zhou et al. developed a new antimicrobial monomer system and loaded it with amorphous calcium phosphate nanoparticles in order to prevent biofilm formation and secondary caries on the composite structure. Using dimethylaminohexane methacrylate (DMAHM) monomers with 6 carbon chains as antimicrobial monomers, they synthesized dimethylaminododecyl methacrylate (DMADDM) monomers with 12 carbon chains, similar to the work of Chan and Zhang and loaded amorphous calcium phosphate nanoparticles (nACP) produced by spray dryer technique as the supportive phase. As a result of their studies, they determined that the DMADDM monomer showed more antimyctobial effect compared to the DMAHM monomer. They determined that DMADDM-NACP nanocomposites had similar strength values compared to systems using tertiary ammonium dimethacrylates, but reduced biofilm formation on the composite by only 5%. In light of their findings, they suggested that the carbon chain length of the monomer is highly effective in antimicrobial activity.

Jan et al. focused on polymerization shrinkage, one of the most common problems in dental restorations, and aimed to reduce the polymerization shrinkage and improve the hardness values of the composite structure by modifying dimethacrylate monomers with diisocyanate side groups. As a result of the studies, they determined that the polymerization shrinkage can be reduced and the surface hardness of the composite can be increased depending on the chain length with the use of diisocyanate side groups.

Khan et al. conducted studies to improve the bonding between the filling material and the tooth interface and to release fluoride. In this context, nano fluorapatite (nFA) particles produced by the sol-gel method were bonded to organic resin composed of urethane monomeric structures via diisocyanate side chains. They determined that the composite produced showed better bonding to the tooth structure compared to conventional composites and fluoride release in the long term and suggested that this composite structure can be used as a filling material.

Liu et al. investigated the morphology, loading, and mechanical properties of composites comprising BisGMA/TEGDMA organic resin structures with and without silica nanoparticles by adding silanized hydroxyapatite (DK-sHA) particles with urchin-like morphology. They found that the mechanical properties of the composite could be improved by loading the silica-free composite structures with 5 and 10 wt% of the DK-sHA supportive phase, and at loading levels of 20 to 30%, the modulus of elasticity and microhardness values of the composite increased, but the strength did not increase further. Compared to silanized amorphous hydroxyapatite and whisker hydroxyapatite, they found that DK-sHA was embedded in the resin and homogeneously distributed in the composite. It was determined that the strength and modulus of elasticity values of the composite could be significantly improved when loaded into composite systems comprising silica particles.

Taubock et al. investigated the effect of alkaline bioactive glass nanoparticles (SiOs-NasO- CaO-PsOs-BisOs) loaded in dental resin on the properties of the composite. They found that 20% loading did not affect the microhardness, but significantly increased the percentage of monomer conversion.

Hojati et al. loaded ZnO nanoparticles into the composite material to improve the antimicrobial effect of dental restorative materials and evaluated the antimicrobial effect of the composite on Streptococcus mutants bacteria and the physical and mechanical properties of the material. They found that bacterial growth was significantly reduced with increasing loading of ZnO nanoparticles and the bending strength, compressive modulus, and monomer conversion values remained unchanged compared to conventional composite systems.

Jan et al. modified Bis-GMA monomers and added toluene 2,4-diisocyanate (TDI) and 1 ,6- hexamethylene diisocyanate (HDI) functional side groups to this monomer system in order to solve the problem of polymerization shrinkage of dental composites. They determined that the resin modified with TDI, which contains a high percentage of functional side groups, showed less cytotoxic effect than the resin modified with HDI. In addition, they suggested that TDI-modified resin caused less toxic effects compared to BisGMA monomers due to the compression of toxic resin monomers in the structure.

In brief, recent studies on existing commercial dental composites have shown that restorative composite filling materials currently provide adequate physical and mechanical strength. For this reason, in the last three years, research on resin-based composite filling materials has focused on improving the biological properties of the composite such as antimicrobial and remineralization effects, as well as chemical properties such as reducing polymerization shrinkage and increasing monomer conversion percentages.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to an acrylic dental composite filling material comprising nanocrystalline cellulose (abbreviated as NCC) with regenerative and antibacterial properties, which overcomes disadvantages in the related technical field and offers additional technical advantages.

One aspect of the invention is to provide an acrylic dental composite filling material with improved edge conformity by reducing polymerization shrinkage.

One aspect of the invention is to provide an acrylic dental composite filling material with improved antibacterial and biological properties as well as improved mechanical properties.

DETAILED DESCRIPTION OF THE INVENTION In this detailed description, the subject matter of the invention relates to an acrylic dental composite filling material comprising nanocrystalline cellulose with regenerative and antibacterial properties and is described only by way of non-limiting examples for a better understanding of the subject matter.

Synthesis of Supportive Phase Systems

The acrylic composite filling material of the present invention comprises nanocrystalline cellulose (NCC) and at least one of silica (SiOs) and/or silica/zirconia (Si/Zr) as the supportive phase system. Celluforce NCV100 commercial product with a crystal density of 1 .5 g/cm³ and a particle size of 1-50 pm was used as the NCC supportive phase structure.

Production of Silica Supportive Phase Structure

SiOs supportive phase structure is obtained by drying HS-40 colloidal silica solution in a rotary evaporator at 60°C, 120 rpm for 3 hours under 28 mbar pressure. In order to reduce the grain size of the silica nanoparticles obtained as a result of drying and to prevent agglomeration formation, the nanoparticles are ground in a ball mill for 24 hours.

Silanization of Supportive Phase Structures

Silanization of Silica and Silica/Zirconia Supportive Phase Structures

• 100 mL acetone:water (1 :3) solution is prepared in a sealed glass bottle and stirred for 15 min.

• The solution to which an appropriate amount of A174 is added is stirred for 15 min.

• The modified supportive phase system is then added to this solution under vigorous stirring and stirred for 1 h.

• After stirring, the mixture is filtered by vacuum filtration and washed in an acetone/water solution to remove the unreacted silanizing agent.

• Finally, the precipitates obtained are dried in a rotary evaporator for 2 h.

Silanization of NCC Supportive Phase Structures

NCC Silanization with CTMAB (Cetyl trimethyl ammonium bromide) • The same weight of NCC and CTMAB are added to a three-necked glass flask and reacted at 60°C for 3 hours.

• CTMAB-treated NCC is centrifuged at 4000 rpm for 3 min.

• The silanized NCC is dried in a Rotary Evaporator.

NCC Silanization with APTES (3-aminopropyltriethoxysilane)

• NCC is dispersed in a 75:25 (v/v) ethanokwater solution.

• pH is adjusted to 4.5 by using acetic acid and stirred for 30 min.

• APTES hydrolysis process is carried out in 75:25 ethanokwater solution.

• APTES/Ethanol/Water solution is slowly added to the NCC/Ethanol/Water solution and stirred for 2 h.

• Centrifugation is performed 3 times for 5 minutes at 4000 rpm.

• The precipitate is dried using a Rotary Evaporator.

Production of Composite Filling Materials (Method 1)

- BisGMA in the range of 1 to 5 wt% is stirred in an ultrasonic water bath at 40°C for 10 min. The organic resin part of the composite structure is prepared by adding HEMA in the range of 5-10 wt%, UDMA in the range of 5-10 wt%, and TEGDMA in the range of 1-5 wt%,

- The supportive phase system comprising mixtures of nanocrystalline cellulose (NCC) and at least one of the SiOs, SiOs/Silane, Si/Zr nanocluster, Si/Zr/Silane nanocluster material group in ratios ranging from 50-90 wt% is added to the prepared organic matrix mixture and stirred for 1 day in an ultrasonic water bath or with a speed mixer until a homogeneous mixture is obtained.

- Camphorquinone or diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide or phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide or 1 -phenyl-1 ,2-propanedione (0.2%) and 4-EDMAB (0.8%) is added to the prepared mixture and stirred in an ultrasonic bath for 3 hr.

- Production of Composite Filling Materials (Method 2) - BisGMA (1 -5%) is mixed in an ultrasonic water bath at 40°C for 10 min. The organic part of the composite structure is prepared by adding HEMA in the range of 5-10 wt%, UDMA in the range of 5-10 wt%, and TEGDMA in the range of 1 -5 wt%,

- The supportive phase system comprising the mixtures of nanocrystalline cellulose (NCC) and at least one selected from the material group consisting of SiOs, SiOs/Silane, Si/Zr nanocluster, Si/Zr/Silane nanocluster in ratios ranging from 50-90 wt% and camphorquinone or diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide or phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide or 1 -phenyl-1 ,2-propanedione in the range of 0.1 -0.5 wt% and 4-EDMAB in the range 0.5-1 .0 wt% are added to the prepared mixture and stirred with a speed mixer.

- The samples are kept in a vacuum oven at 37°C for 30 min to remove any air bubbles that may have remained in the structure of the mixture.

The use of nanocrystalline cellulose contained in the acrylic composite filling material of the invention in combination with at least one of SiOs, SiOs/Silane, Si/Zr nanoclusters, Si/Zr/Silane nanoclusters involves a novelty for the related technical field. The NCC in the composite filling material of the invention allows it to be more environmentally friendly, and biocompatible, with adequate mechanical and physical properties, high thermal stability, and low thermal expansion coefficient than composite filling materials in the prior art. In addition, the thermal stresses that occur in restored teeth due to the different thermal conductivity and thermal expansion coefficients of dental tissues and restorative materials are prevented.

Claims

1. The invention is an acrylic dental composite filling material comprising a light-curable and polymerizable organic compound, a photoinitiator, and a supportive phase system, characterized in that it comprises;

• a mixture of nanocrystalline cellulose (NCC) and at least one of the compounds SiOs, SiOs/Silane, Si/Zr nanoclusters, Si/Zr/Silane nanoclusters as a supportive phase system to impart regenerative and antibacterial properties to composite filling materials,

• mixtures of BisGMA, HEMA, UDMA, and TEGDMA compounds as organic compounds,

• at least one of a group consisting of CQ, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, 1 -phenyl-1 ,2-propanedione, 4-EDMAB as a photoinitiator.

2. A composite filling material according to claim 1 , wherein the BisGMA is in the range of 1-5 wt%.

3. A composite filling material according to claim 1 , wherein the HEMA is in the range of 5-10 wt%.

4. A composite filling material according to claim 1 , wherein the UDMA is in the range of 5-10 wt%.

5. A composite filling material according to claim 1 , wherein the TEGDMA is in the range of 1-5 wt%.

6. A composite filling material according to claim 1 , wherein the CQ is in the range of 0.1 - 0.5 wt%.

7. A composite filling material according to claim 1 , wherein the diphenyl(2,4,6- trimethylbenzoyl)phosphine oxide is in the range of 0.1 -0.5 wt%.

8. A composite filling material according to claim 1 , wherein the 1 -phenyl-1 , 2- propanedione is in the range of 0.1 -0.5 wt%. A composite filling material according to claim 1 , characterized in that the 4-EDMAB is in the range of 0.5-1 wt%. A composite filling material according to claim 1 , characterized in that the nanocellulose component is silanized. A composite filling material according to claim 10, characterized in that the nanocellulose component is silanized with CTMAB and APTES compounds. A composite filling material according to claim 1 , wherein the supportive phase system comprising the nanocrystalline cellulose and at least one of SiOs, SiOs/Silane, or Si/Zr nanoclusters or Si/Zr/Silane nanoclusters is in the range of 10-90 wt%. A composite filling material according to one of claims 1 -12, characterized in that it comprises a pigment in addition to the organic compound and the supportive phase system. A composite filling material according to claim 13, characterized in that the pigment is 0.01 -1 wt%. A composite filling material according to one of the claims 13-14, characterized in that the pigment is selected from a group consisting of Duranat Yellow Iron Oxide (Pigment Yellow 42 & 43 Cl 77492), Duranat Red Iron Oxide (Pigment Red 101 Cl 77491), Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 1-Phenyl-1 ,2-propanedione 98%, Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, Duranat Brown Iron Oxide (Pigment Brown), Duranat Black Iron Oxide (Pigment Black 11 Cl 77499), iron oxide (FesOs - red), ferric hydroxide (FeOOH - yellow), TiOs, E171 Titanium Dioxide; Pigment White 6 Cl 77891 or mixtures thereof. A production method of a light-curable and polymerizable acrylic dental composite filling material showing an antimicrobial effect for restorative purposes according to one of the claims 1 -15, characterized in that it comprises the following process steps; a) mixing BisGMA in the range of 1 to 5 wt% in an ultrasonic water bath and preparing an organic matrix of the composite structure by adding HEMA in the range of 5 to 10 wt%, UDMA in the range of 5 to 10 wt% and TEGDMA in the range of 1 to 5 wt%, b) adding the supportive phase system comprising the mixtures of nanocrystalline cellulose (NCC) and at least one selected from the material group consisting of SiOs, SiOs/Silane, Si/Zr nanocluster, Si/Zr/Silane nanocluster in ratios ranging from 50 to 90 wt% to the prepared organic matrix mixture and mixing in an ultrasonic water bath or with a speed mixer until a homogeneous mixture is obtained, c) adding camphorquinone or diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide or phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide or 1-phenyl-1 ,2-propanedione (0.2%) and 4-EDMAB (0.8%) to the prepared mixture and mixing it in an ultrasonic bath, d) leaving the samples in a vacuum oven to remove any air bubbles that may have remained in the structure of the mixture, e) bringing the prepared composite matrix to room temperature before application, mixing it with a cement spatula, and placing it in teflon molds, f) placing glass sheets on both sides of the molds and compressing them by applying pressure, g) treating samples with a blue-LED light device. A production method according to claim 15, characterized in that in step c), 0.2 wt% camphorquinone and 0.8 wt% 4-EDMAB are added and mixed in an ultrasonic bath. A production method according to one of the claims 15-16, characterized in that the mixing process mentioned in the process step a) is carried out at 40°C for 10 minutes. A production method according to one of the claims 15-17, characterized in that the supportive phase system mentioned in process step b) is added by 70%. A production method according to one of the claims 15-18, characterized in that the mixing process mentioned in process step b) is carried out for 1 day. A production method according to one of the claims 15-19, characterized in that the mixing process mentioned in process step c) is carried out for 3 hours.

22. A production method according to one of the claims 15-20, characterized in that the leaving process mentioned in process step d) is carried out for 30 minutes at 37°C. 23. A production method according to one of the claims 15-21 , characterized in that the treating process with the blue-LED light device mentioned in process step g) is carried out for 20 seconds.

24. A production method according to one of the claims 15-22, wherein it is a dental composite filling material obtained by the said method.