NANOROBOTICS A NEW FRONTIER IN DENTISTRY

Robert Freitas Jr. hypothesized the employment of micrometer-sized dental nanorobots that will be capable of many functions as well as precise local anaesthesia, decay excavation and tooth reconstruction, permanent desensitisation, single-visit dental medicine realignment, enamel reinforcement and regular oral health maintenance.

NANOROBOT

A nanorobot is actually a manageable machine at the nm (A nanometer could be a billionth a part of a meter, i.e., about 1/80,000 of the diameter of an individual's hair. Scale of nm ranges from (1-100nm) or molecular scale that's composed of nano-scale elements and algorithmically responds to input forces and data. 

Nanorobots would represent any active structure (nano-scale) capable of exploit, sensing, signalling, info processing, intelligence, and swarm behaviour at nano-scale. 

The nanorobots are invisible to the oculus, techniques like scanning electron microscopy (SEM) and atomic force microscopy (AFM) are being utilized to check these nano-scaled devices. 

These nanorobots offer advantages in numerous areas similar to synthesis of recent materials with advanced properties, production technology, info  technology, medical applications, transportation, etc. 

Because of their advanced properties nanorobots are wide utilized in the sector of medicine wherever they perform inspections, operations, treatment of diseases within the human body, imaging and delivery of medicine to focus on cells like cancer cells. 

The advances of nanorobots in medicine are comparatively slow as compared to the medical field. 

Nanorobotics could be a field that requires cooperative efforts between physicists, chemists, biologists, computer scientists, engineers, and alternative specialists to figure towards this common objective and leads emergence of newer branches like nanomedicine and nanodentistry in future.

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MANUFACTURE

Adriano Cavalcanti, a research worker at Centre for Automation of Nanobiotech, Brazil, recommended 2 approaches for manufacturing nanorobots: 

• organic 
•  inorganic.

Organic nanorobots 

• These are primarily adenosine triphosphate and deoxyribonucleic acid based mostly molecular machines, conjointly referred to as bio-nanorobots. this is often supported the event of RNA and ATP devices, or changed microorganisms to realize biomolecular computation, sensing and exploit for nanorobots.

Inorganic nanorobots 

• The development of inorganic nanorobots relies on building customised miniature nanoelectronic devices. compared with bionanorobots, a significantly higher complexity of integrated nanoscale parts may well be achieved during this field that's appropriate for nanorobotic dentistry.
• Circular saturated hydrocarbons with a diamond like structure referred to as diamondoid materials are wide proposed, because of their exceptional molecular structure they're with chemicals and thermally stable, will self-assemble and lightweight, creating them appropriate materials for nanorobot construction.

DESIGN & COMPONENTS 

Several styles of nanorobots are projected, of that a multiple manipulating armed spider-like configuration is believed to be the foremost ideal style because it allows fast motility and multitasking capability.

The surface ought to be super sleek in order that once the nanorobots are introduced within the body, they'll stop the triggering of body's system, so permitting them to figure expeditiously.

The four major components in a very nanorobot are as follows:

• Camera
• Payload
• Capacitor
• Swimming tail.

Manufacturing them also will involve sensors, actuators, control, power, communications, and interfacing across abstraction scales and between organic/inorganic likewise as biotic/abiotic systems.

Photo credit :https://electronics.howstuffworks.com

MECHANISM OF ACTION 

The powering of nanorobots is predicted to be done by the metabolism of:

• Local glucose
• Oxygen
• Externally equipped acoustic energy.

They can be created to figure in check by on-board computers capable of playing around one thousand or a lot of computations per second. 

Communication with the device are often obtained by acoustic communication steering network put in within the body that may give high point accuracy to any or all passing nanorobots and facilitate to keep track of various devices in the body. 

once the task of the nanorobots is completed, they'll be retrieved by permitting them to effuse themselves via the usual human excretory channels. These may also be removed by active scavenger systems.

Freitas in 1999 represented however medical nanorobots may use specific motility mechanisms to crawl or swim through human tissues with:

• Navigational recession
• Cytopenetration 
• Use any of multitudes of techniques to watch, interrupt, or alter nerve impulse traffic in individual nerve cells.

According to the contemporary theories, dental nanorobots ought to have a minimum of the subsequent 2 suggests that of communication:

• By suggests that of light signals through optical nanosensors
• By chemical signals through chemical nanosensors (i.e., nanorobots observance the aldohexose level).
• The principal part within the exterior surface of the nanorobots is that the carbon (C) that is in the sort of diamond. alternative parts embody chemical element (H), sulfur (S), oxygen (O), nitrogen (N), fluorine (F), and silicon (Si), that are employed in nanoscale gears and alternative elements.
• Glucose or its alternative natural substitutes and oxygen may be the supply of propulsion within the body. 
• Depending on the precise task to be performed, they need specific biochemical or molecular components

NANODIAGNOSTIC 

Nanodiagnostic devices are often used for early disease identification at the cellular and molecular levels. Nanomedicine may increase the potency and reliableness of in vitro diagnostics, through the utilization of selective nanodevices to gather human fluids or tissue samples and to create multiple analyses at the subcellular level. From an in vivo perspective, nanodevices may be inserted into the body to spot the first presence of a disease, or to spot and quantify toxic molecules, neoplasm cells, so forth. 

NANO ANESTHESIA 

When nanotechnology or nanorobots are wont to induce anaesthesia, the gingiva of the patient is instilled with a colloidal solution containing countless active, analgesic, micron-sized dental robots that reply to input equipped bythe dentist. Nanorobots up-to-date with the surface of the crown or tissue layer will reach the pulp via the gingival sulcus, lamina propria, or dentinal tubules. 

Once within the pulp, they stop working all sensations by establishing management over nerve-impulse traffic in any tooth that requires treatment. 

After completion of treatment, they restore this sensation, thereby providing the patient with anxiety-free and needleless comfort. 

The anesthesia is fast-acting and reversible, with no side effects or complications related to its use. 

TREATMENT IN  DENTAL HYPERSENSITIVITY 

Hypersensitivity is caused by changes within the pressure transmitted hydrodynamically to the pulp. 

The dentinal tubules of a hypertensive tooth have double the diameter and eight times the surface density of these in nonsensitive teeth. 

These characteristics have light-emitting diode to the utilization of nanorobots that by selection and exactly obstruct tubules in minutes, by using native, native materials, so giving patients a fast and permanent cure 

This would offer immediate and lasting relief to the patient as compared to traditional strategies.

Nanorobot in dentinal tubule

Photo credit: https://ipj.quintessenz.de

IMPRESSION MATERIAL

Nanofillers are integrated into vinylpolysiloxanes , producing a unique siloxane impression material that features a higher flow, improved hydrophilic  properties, and increased exactness detail

Photo credit: https://ipj.quintessenz.de

NANO DENTIFRICE 

Nanorobotic dentifrices, once delivered either by mouthwash or tooth paste, will cover all sub gingival surface thereby metabolizing trapped organic matter into harmless and inodorous vapors. 

Properly designed dentifrobots will determine and destroy infective bacterium that exist within the plaque et al.. These invisibly little dentifrobots are purely mechanical devices that safely deactivate themselves once swallowed.

NANOROBOTICS IN ORTHODONTICS 

Orthodontic robots permit painless tooth uprighting, rotating, and vertical repositioning, likewise as speedy tissue repair. a replacement stainless-steel wire that uses nanotechnology is being studied that mixes ultra-high strength with sensible deformability, corrosion resistance, and surface finish.

Orthodontic nanorobot

Photo credit :https://www.researchgate.net/figure/Orthodontic-nanorobots_fig2_267633456 [accessed 9 Jun, 2020] 

TREATMENT & DIAGNOSIS OF ORAL CANCER

Saliva is employed as a cheap and noninvasively obtained diagnostic medium that contains proteomic and genomic markers for molecular disease identification. 

Exosome, a membrane-bound secretory vesicle, is one such marker whose level is elevated in malignancy. 

This marker has been studied by exploitation atomic force research, that employs nanoparticles. 

The nanoelectromechanical system, oral fluid nanosensor test, and optical nanobiosensor can even be used for diagnosis carcinoma. 

Nanoshells, that are minute beads, are specific tools in cancer therapeutics. 

Nanoshells have an outer metallic  layer that by selection destroys cancer cells, whereas going normal cells intact. 

Brachytherapy is a sophisticated type of cancer treatment. 

Still beneath trial are nanoparticle-coated, radioactive  sources placed getting ready to or inside the neoplasm to destroy it. 

Other uses of nanovectors include drug delivery across the blood–brain barrier within the treatment ofAlzheimer’s and Parkinson’s diseases.

Nanorobots will be programmed to penetrate cancerous lesions, determine neoplastic cells and destroy them by increasing the intracellular pressure or temperature utilizing focal lasers, microwaves or ultrasonic waves.

Photo credit: www.cancer.gov

NANOROBOTICS IN ENDODONTICS 

Dental nanorobots would possibly use specific motility mechanism to penetrate human tissue with navigation exactness, acquire energy and sense to control their close in real time. 

Dental nanorobots might be placed intracoronally for non-vital tooth bleaching for pulpal regeneration. 

They will swim in pulp chamber and canal in order that can stop the inflammation and conjointly management the infection within the canal. 

NANONEEDLE 

Nanosized stainless-steel crystals incorporated into suture needles are developed.

Cell surgery is also potential within the close to future with nanotweezers, that are currently under development.

BONE REPLACEMENT MATERIAL 

Bone could be a natural nanostructure that's composed of organic compounds (mainly collagen) and strengthened with inorganic ones. 

Nanorobotics aims to keep up its nanostructure for its application in dentistry and orthopaedics. 

Bone defects may be treated by victimization the HA nanoparticles

Nanotechnology aims to emulate this natural structure for orthopedic and dental applications and, more particularly, for the event of nanobone. 

Nanocrystals show a loose microstructure, with nanopores set between the crystals. 

The surfaces of the pores are changed such that they adsorb protein, thanks to the addition of silicon oxide molecules. 

Bone defects may be treated by victimization these hydroxyapatite nanoparticles. 

NANOSOLUTION

Because they turn out distinctive and dispersible nanoparticles, nanosolutions are often used as bonding agents. Homogeneity is ensured, as a result of the adhesive is mixed perfectly whenever. Nanoparticles have additionally been used as sterilizing solutions within the style of nanosized emulsified oil droplets that bombard pathogens 

NANOCOMPOSITE

Microfillers in composites and microcore materials have long been in use. 

Although the filler particle size can not be reduced below one hundred nm, nanocomposite particles are minute enough to be synthesized at the molecular level.

These nanoparticles improve the compressive strength of the material. Filler particles of submicron size, like zirconia, also are necessary to enhance polishability and esthetics. However, once particles of this size are used, the material is also a lot of susceptible to brittleness and cracking or fracturing when hardening.

To address this issue, hybrid composites and composites containing a wider distribution of filler particles have acquire use. 

Although these composites show a far better balance of strength and esthetics, they're weak because of nanoparticle clumping or agglomeration. 

This drawback is overcome by incorporating a proprietary coating method throughout the particle manufacturing procedure, thereby eliminating weak spots and providing consistent strength throughout the whole “fill” of the core build-up. 

Additionally, the even distribution of nanoparticles ends up in a smoother, creamier consistency and improves flow characteristics. 

Once the material is cured to its hardened state, these properties contribute to the dentin-like cutability and polishability of the material

Photo credit: https://ipj.quintessenz.de 

DENTAL IMPLANT

The determinant factors for successful osseointegration are surface contact space and surface topography. 

However, bone bonding and stability additionally play a task. 

Bone growth and accrued sure thing are often effectively fast with implants by using nanotechnology. 

The addition of nanoscale deposits of hydroxyapatite and calcium phosphate creates a a lot of complicated implant surface for bone-forming cell formation. 

Extensive analysis on the results and resultant optimisation of microtopography and surface chemistry has created ground-breaking strides in material engineering. 

These new implants are a lot of acceptable, as a result of they enhance the combination of nanocoatings resembling biological materials to the tissues.

TOOTH REPAIR AND  RECONSTRUCTION BY NANO TECHNOLOGY 

Replacement of the complete tooth, together with the cellular and mineral parts, is said as complete dentition replacement. 

This therapy is feasible through a mix of nanotechnology, genetic engineering, and tissue engineering. 

Complete dentition replacement was the idea for analysis by Chan et al., who recreated dental enamel, the hardest tissue within the human body, by exploitation extremely organized microarchitectural units of nanorods.

Photo credit: https://ipj.quintessenz.de

NANOENCAPSULATION

Nanoencapsulation were developed by South West research Institute, that are targeted unleash systems as well as novel vaccines, antibiotics, and drug delivery with reduced side effects. 

In future, specialised nanoparticles might be designed to focus on oral tissues, as well as cells derived from the periodontium

Targeted unleash systems that comprehend nanocapsules are below trial for inclusion in vaccines and antibiotics 

CHALLENGES OF NANOTECHNOLOGY 

• Engineering challenges
• Feasibility of production technique
• Precise positioning and assembly of molecular scale elements
• Manipulating and coordinative activities of various microscale robots.

• Biological challenges
• Development of bio-friendly nanomaterials
• Biocompatibility with all intricate of the human body.

• Social challenges
• Ethics
• Public acceptance
• Regulation and human safety.

NANOHAZARD 

Numerous problems and issues ought to be addressed  since nanotechnology and nanorobotics may be a terribly recent discovery and is merely just being put in to United States of America.

Because the long-term effects of nanorobots don't seem to be best-known, their future prospective continues to be questionable. 

Nanomaterials released by the nanorobots within the surroundings are often changed by temperature, pH, and totally different biological conditions, and also the presence of different pollutants will have unsafe and irreversible effects on human health and the environment. 

CONCLUSION 

There are several commercially accessible applications of nanotechnology in dental medicine, particularly as relates to reconstruction procedures and instrument sterilization.

Still others, equivalent to squid ink aren't Food and Drug Administration approved–but show promise.

Nanodentistry, whereas wonderful, isn't while not contestation. There are conflicting views on toxicity in living tissue. whereas experimental ends up in vitro have made astounding results, not all experiments have with success translated to clinical applications 

REFERENCE 

• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3723292/ 
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