Introduction

Since its inception, the incorporation of nanotechnology into "dental interventions" has significantly advanced the identification, prevention, and management of a broad range of dental conditions (1). Dental methods aimed at dental rehabilitation, regional anesthesia, orthodontic realigning, permanent hypersensitivity treatment, covalent bonding diamondized enamel, dental health preservation using mechanical dentifrobots, and the formation of artificial bone and teeth are among the possible uses of nanotools in dentistry (2). There is a growing consensus that using nanotechnology in dental medicine will greatly help in diagnosing, preventing, and treating oral health problems.

The primary strategies that aid in the practical application of nanotools include a bottom-up method and a top-down approach. A bottom-up approach entails organizing simpler elements into more intricate ones. It focuses on the use of miniature nanorobots that can be controlled to perform a variety of manual tasks, including administering local anesthesia, honing the enamel surface with diamondized covalent bonding, treating tooth sensitivity, improving dental longevity and aesthetics, and using photosensitizers like quantum dots to strike particular targets (3). The second approach is a top-down approach, which encourages the creation of smaller-dimensional nanostructures from bigger components. Nanoscaled solutions, needles, fillers, composites, and bone replacement materials are typically used in this procedure (4). AdperTM single bond plus is a type of a dentin adhering nanosolution with a single step application process (5). In order to reduce tissue injury, suture needles with nanosized stainless steel crystals, such as Sandvik Bioline RK 91TM needles, have been created (6). The saliva can be examined by the biochemical sensing devices in salivary diagnostics, which also uses the top-down technique of nanotechnology. An example of an automated and integrated system to identify the targeted protein and nucleic acid in saliva is the oral fluid nanosensor test (OFNASET) (7, 8).

One of the most popular uses of nanotechnology is in oral medicine, which has the potential to increase people's quality of life through enhancing dental health. Years of controversy have surrounded the safety of using nanoparticles on people, however research on these materials has shown that there are actually more benefits to using them than drawbacks (9). A scale between 1 and 100 nm is used in nanoscience research (10). Environmentally friendly nanofillers using "green chemistry" have also been developed as a result of research in nano-biotechnology (11, 12). Due to their minute size, high density, and distinctive physicochemical characteristics, nanomaterials have received a lot of interest for usage in a variety of dentistry procedures (13-15). Finding composites that can restore the original dental appearance while simulating missing dentinal tissue is a challenge that most dentists face. The creation of sophisticated nanomaterials using a bio-mimetic approach based on nanotechnology has been seen as a more recent method (16, 17). Biofilms on the surfaces of teeth in the mouth are broken down or prevented from forming by oral antibacterial substances. The antibacterial capabilities of biomaterials may be enhanced by adding components like silver, gold, or titanium nanoparticles (18). Metallic nanoparticles (Metal NPs) have a wide surface area, which expands their antimicrobial potential. Moreover, these materials can also improve the strength and endurance of mechanical characteristics (19). Dental nanocomposites may contain inorganic nanoparticles made predominantly of metal NPs or metal oxide NPs as fillers (20, 21). The formation of colonies along the margins between the tooth surface and restorative material by a pathogenic microorganism like Streptococcus mutans results in tooth decay. Such antibacterial components can greatly increase the effectiveness of dental restorations (22-24).

Methodology

This study is based on a comprehensive literature search conducted on October 2, 2022, in the Medline and Cochrane databases, utilizing the medical topic headings (MeSH) and a combination of all available related terms, according to the database. To prevent missing any possible research, a manual search for publications was conducted through Google Scholar, using the reference lists of the previously listed papers as a starting point. We looked for valuable information in papers that discussed the information about improvement in the quality of life through nanoparticles used in restorative dentistry. There were no restrictions on date, language, participant age, or type of publication.

Discussion

Nanomaterials have undergone impressive development in recent years, taking them from a theoretical base to practical use. There are now numerous uses for nanomaterials in various subspecialties of dentistry (25-32). The diversity of goods available for different dental applications is anticipated to significantly rise in the coming years as a result of ongoing research into the development of novel nano-products.

The evaluation and treatment of problems affecting the teeth and their surrounding tissues are the focus of restorative dentistry. For the restoration of tooth function and the repair and replacement of damaged tooth structures as well as better aesthetics, advanced procedures are required (33). In the past few years, resin-based dental restorative materials have made significant progress. Dental composite resin's mechanical performance, minimal polymerization contraction, strong wear resistance, and surface hardness can all be considerably improved by adding nanoparticles to the matrix (34, 35). According to a recently published study, adding fluoro-aluminosilicate glass nanoparticles to GIC enhanced its mechanical characteristics and aesthetics (35). Nanoionomers (KetacTM Nano; 3M ESPE) have recently been authorized for use in therapeutic settings (1). The four categories of nanomaterials include polymers, metals, composites, and ceramics (36).

Nanocomposites

To date, nanocomposites for the repair of tooth structure have made one of the most significant contributions to restorative and cosmetic dentistry (37). Nanoscale particles and matrix material make up nanocomposites. These composites, which differ from the present microfilled and hybrid resin-based composites in terms of toughness and aesthetics, are defined by filler-particle diameters of less than 100 nm. The synthesis process has an impact on the substance's characteristics. The nanocomposite's matrix can be polymeric, metallic, or ceramic (38, 39). Nanocomposites' characteristics aid in minimizing polymerization loss (40). Silver and zinc oxide nanoparticles, as well as composites, have demonstrated to have effective antibacterial properties against Lactobacilli spp. and Streptococcus mutans (41). Nanoscopic carbon-based fillers, layered clay, pervious and hollowed particles, cellulose, and particles containing metallic ions are all components of nanocomposites. Nanotubes and graphene are two examples of the carbon-based fillers. In situ polymerizing, melt mixing, and solution blending are the three processes used to create polymer nanocomposites (42).

Fillers smaller than 100 nm are frequently used in nanotechnology-based composites as Estelite® Sigma and FiltekTM Supreme Plus from Tokuyama America, Inc. and 3M ESPE, respectively. Better dispersion and a larger interfacial area between the matrix and filler should be the results of using filler particle sizes that are gradually smaller. This would boost the finished restoration's flexural strength, surface microhardness, and polishability (43). Their microhardness is higher than that of already employed posterior resin-based composites, and the improved polishability properties in turn result in a smoother surface with better shade qualities. Nanofilled restoratives are currently being used with nanocluster particles as tiny as 2-20 nm (32). These smaller particles allow for the maximization of features including optical qualities, which may have an impact on aesthetic dentistry (32) [translucent shades have fillers of 5–20 nm]. Particles can be separated from the composite matrix by polishing and abrasions brought on by function. However, polishing and functional abrasions would only permit weakly connected nanoclusters to dissociate from the nanocomposites; as a result, a well-polished repair surface would continue to be smooth for a considerable amount of time. Additionally, the particles that are removed from the nanocomposites' surfaces and cause flaws to emerge during abrasion are nanoscale in size and smaller than the wavelength of light. Nanocomposites have better optical character because particles with a wavelength of visible light (0.4 to 0.8 m) do not reflect light (32). Because the fillers in nanocomposites are smaller than the wavelength of light, they are more translucent and enable the creation of more aesthetic restorations with a wide variety of color possibilities (4). Bigger particles in the 0.4-5 micrometer range can be found in nanohybrids (44). Since they offer good strength and stability, nanohybrid composites containing nanoparticles can be incorporated in ceramic laminates (45, 46). Nanocomposites have a number of benefits, including reduced weight, excellent thermal and electrical properties, antimicrobial activity, and the ability to remineralize dental defects (47, 48).

Adhesives

Dental adhesives are resinous monomeric substances in solvents that facilitates substrate interaction (49). The failure of a restoration occurs when subsequent bacterial invasion occurs; the adhesives' antimicrobial properties aid to lessen the bacterial impacts (50). The surface tension of adhesives is increased by the nanoparticles (51). The addition of unstructured nanoscaled calcium phosphate and silver particles in the adhesives improved the material's bond strength and had a positive antimicrobial action (50). The adhesives' microshear bond strength was demonstrated by the aluminum oxide addition (52). The microshear binding strength of the adhesives incorporating magnetic nanoparticles was good, and they penetrated the dentin more effectively (53).

Nanoionomers

Nanoionomers, or glass ionomers (GI) incorporating nanoparticles, are used to make glass ionomer cement (GIC). A major reason why GIC is so popular is because of how it chemically adheres to the surface of the tooth. Fluoroaluminosilicate glass is enhanced with nanomers and nanoclusters (54). The fluoride-releasing and aesthetic features of the nanoionomer are achieved this way. In comparison to the traditional GIC, the nano-GI is more translucent and optically superior (55). By filling the crevices amongst the glass particles in GIC, the nanoparticles are manually combined along with the cement to minimize porosity (56). Pre-reacted GI technology was developed utilizing GIC and composite material to create "Giomer," and hydroxyapatite and glass powder to create "Mainomer." Bioactive glass, CPP-ACP, Reinforced GIC, Zirconomer, Chlorhexidine GIC, Nano Bioceramic reinforced GIC, and Ceramir and Giomer are new developments in GIC (57). On the surface of the enamel, bioactive glass displays remineralizing potential (58). By including bioactive glass nanoparticles, the resin-modified GI can be further altered (59). Nanoionomeric substances are advantageous due to their stronger bond formation, chemical stability, and insoluble nature (60).

Endodontic sealer

Endodontic sealers help to secure the root canal in three dimensions by providing a solid core material. These sealants support the root canal by adapting to the imperfections and voids in the canal. The antimicrobial activity, periapical repair, and hard tissue development are just a few of the features of sealer (61). They are categorized as GIC, zinc oxide eugenol, salicylate, epoxy resin, methacrylate resin, and tricalcium sealers based on their characteristics, content, and kind of setting reaction. Comparing the tricalcium silicate to AH Plus (62), it exhibits minimal microleakage. Recently, a bioceramic-based nanoparticle (Endosequence BC sealer) (63) was created. Delivery of the substance from 0.012 capillary needles in nanomaterials including nanoparticles aids in adjusting to the uneven dentin surface (64). Nano endodontic sealers have the advantage of sealing better than conventional sealers (65) and employing nanoparticles effectively acts as an antimicrobial agent (66). A new nano-based endodontic sealer called Nanoseal Plus, aids in filling the voids in the root canal. It consists of rod-shaped calcium phosphate hydroxyapatite nanoparticles with an average diameter of 40–60 nm which easily enter empty spaces (67). Recent research has used nanoparticles to improve the properties of primer adhesive, which will be used in future trials on amalgam.

Advantages of nanoparticles

While metals like iron do not have bactericidal qualities at the macroscopic level unlike the nanoscopic silver, copper, and zinc, they do have antimicrobial effect at the nanoscopic level. Antibacterial nanoparticles have numerous mechanisms through which they release metal ions, that penetrate into cell walls, and cause membrane damage (68). These particles have an effective encapsulation, protection, and delivering mechanism for releasing. micronutrients. The nanoparticles' reduced size demonstrates benefits such enhanced bioavailability, excellent optical clarity, gravitational segregation, and stability to agglomerate (69). The blood brain barrier can be crossed by the nanoparticles. Therefore, by adding on with properties, the use of nanoparticles results in the improvement of the property of traditional material.

Conclusion

Dental science is heavily reliant on nanotechnology. The nanoparticles have anti-inflammatory, anti-bacterial, and anti-cancer properties. The uses of the nanoparticles in implants, adhesives, nanocomposites, and primer-adhesives are numerous. Nanocomposites have several uses in restorative dentistry and have excellent strength and characteristics. When used with nanocomposites, GIC facilitates the combat of slow setting reactions, poor bond strengths, and diminished or weakened mechanical characteristics. Due to its potential uses and advantages, there is a growing demand for and interest in nano-based dental materials. Nanorobot use is a recent advancement that aids in the battle against microorganisms. Nanotechnology in dentistry has helped in overcoming many shortcomings part of restorative procedures and improved the oral health related quality of life.

Disclosure

Conflict of interest

There is no conflict of interest

Funding

No funding

Ethical consideration

Non applicable

Data availability

Data that support the findings of this study are embedded within the manuscript.

Author contribution

All authors contributed to conceptualizing, data drafting, collection and final writing of the manuscript.