About Me

My photo
I am so clever that sometimes I don't understand a single word of what I am saying.

Thursday, May 3, 2012

Future impact of nanotechnology on medicine and dentistry


Nanodentistry will make possible the maintenance of comprehensive oral health by employing nanomaterials, biotechnology, including tissue engineering, and ultimately, dental nanorobotics. New potential treatment opportunities in dentistry may include, local anesthesia, dentition renaturalization, permanent hypersensitivity cure, complete orthodontic realignments during a single office visit, covalently bonded diamondised enamel, and continuous oral health maintenance using mechanical dentifrobots.

When the first micro-size dental nanorobots can be constructed, dental nanorobots might use specific motility mechanisms to crawl or swim through human tissue with navigational precision, acquire energy, sense, and manipulate their surroundings, achieve safe cytopenetration and use any of the multitude techniques to monitor, interrupt, or alter nerve impulse traffic in individual nerve cells in real time.

These nanorobot functions may be controlled by an onboard nanocomputer that executes preprogrammed instructions in response to local sensor stimuli. Alternatively, the dentist may issue strategic instructions by transmitting orders directly to in vivo nanorobots via acoustic signals or other means.

Inducing anesthesia
One of the most common procedure in dental practice, to make oral anesthesia, dental professionals will instill a colloidal suspension containing millions of active analgesic micron-sized dental nanorobot 'particles' on the patient's gingivae. After contacting the surface of the crown or mucosa, the ambulating nanorobots reach the dentin by migrating into the gingival sulcus and passing painlessly through the lamina propria or the 1-3-micron thick layer of loose tissue at the cementodentinal junction. On reaching dentin, the nanorobots enter dentinal tubules holes that are 1-4 microns in diameter and proceed toward the pulp, guided by a combination of chemical gradients, temperature differentials, and even positional navigation, all under the control of the onboard nanocomputer as directed by the dentist.

There are many pathways to choose from, near to CEJ, midway between junction and pulp, and near to pulp. Tubules diameter increases as it nears the pulp, which may facilitate nanorobot movement, although circumpulpal tubule openings vary in numbers and size (tubules number density 22,000 mm DEJ, 37,000 mm square midway, ans 48000 mm square near to pulp). Tubules branching patterns, between primary and irregular secondary dentin, regular secondary dentin in young and old teeth (sclerosing) may present a significant challenge to navigation.

The presence of natural cells that are constantly in motion around and inside the teeth including human gingival and pulpal fibroblasts, cementoblasts of the CDJ, bacteria inside dentinal tubules, odontoblasts near the pulp dentin border, and lymphocytes within the pulp or lamina propria suggested that such journey should be feasible by cell-sized nanorobots of similar mobility.

Once installed in the pulp and having established control over nerve impulse traffic, the analgesic dental nanorobots may be commanded by the dentist to shut down all sensitivity in any particular tooth that requires treatment. When on the hand-held controller display, the selected tooth immediately becomes numb. After the oral procedures completed, the dentist orders the nanorobots to restore all sensation, to relinguish control of nerve traffic and to engress, followed by aspiration. Nanorobotic analgesics offer greater patient comfort and reduced anxiety, no needles, greater selectivity, and controllability of the analgesic effect, fast and completely reversible switchable action and avoidance of most side effects and complications.

Tooth repair

Nanorobotic manufacture and installation of a biologically autologous whole replacement tooth that includes both mineral and cellular components, that is, 'complete dentition replacement therapy' should become feasible within the time and economic constraints of a typical office visit through the use of an affordable desktop manufacturing facility, which would fabricate the new tooth in the dentist's office.

Chen et al took advantage of these latest developments in the area of nanotechnology to simulate the natural biomineralization process to create the hardest tissue in the human body, dental enamel, by using highly organized microarchitectural units of nanorod-like calcium hydroxyapatite crystals arranged roughly parallel to each other.

Dentin hypersensitivity
Natural hypersensitive teeth have eight times higher surface density of dentinal tubules and diameter with twice as large than nonsensitive teeth. Reconstructive dental nanorobots, using native biological materials, could selectively and precisely occlude specific tubules within minutes, offering patients a quick and permanent cure.

Tooth repositioning
Orthodontic nanorobots could directly manipulate the periodontal tissues, allowing rapid and painless tooth straightening, rotating and vertical repositioning within minutes to hours.

Tooth renaturalization
This procedure may become popular, providing perfect treatment methods for esthetic dentistry. This trend may begin with patients who desire to have their (1) old dental amalgams excavated and their teeth remanufactured with native biological materials, and (2) full coronal renaturalization procedures in which all fillings, crowns, and other 20 th century modifications to the visible dentition are removed with the affected teeth remanufactured to become indistinguishable from original teeth.

Dental durability and cosmetics
Durability and appearance of tooth may be improved by replacing upper enamel layers with covalently bonded artificial materials such as sapphire or diamond, which have 20-100 times the hardness and failure strength of natural enamel or contemporary ceramic veneers and good biocompatibility. Pure sapphire and diamond are brittle and prone to fracture, can be made more fracture resistant as part of a nanostructured composite material that possibly includes embedded carbon nanotubes.

Nanorobotic dentifrice (dentifrobots) delivered by mouthwash or toothpaste could patrol all supragingival and subgingival surfaces at least once a day metabolizing trapped organic mater into harmless and odorless vapors and performing continous calculus debridement.

Properly configured dentifrobots could identify and destroy pathogenic bacteria residing in the plaque and elsewhere, while allowing the 500 species of harmless oral microflora to flourish in a healthy ecosystem. Dentifrobots also would provide a continous barriers to halitosis, since bacterial putrification is the central metabolic process involved in oral malodor. With this kind of daily dental care available from an early age, conventional tooth decay and gingival deseases will disappear into the annals of medical history.

Potential benefits of nanotechnology are its ability to exploit the atomic or molecular properties of materials and the development of newer materials with better properties. Nanoproducts can be made by: building-up particles by combining atomic elements and using equipments to create mechanical nanoscale objects.

Nanotechnology has improved the properties of various kinds of fibers.  Polymer nanofibers with diameters in the nanometer range, possess a larger surface area per unit mass and permit an easier addition of surface functionalities compared to polymer microfibers.  Polymer nanofiber materials have been studied as drug delivery systems, scaffolds for tissue engineering and filters. Carbon fibers with nanometer diamensions showed a selective increase in osteoblast adhesion necessary for successful orthopedic/dental implant applications due to a high degree of nanometer surface roughness.

Nonagglomerated discrete nanoparticles are homogenously manufactured in resins or coatings to produce nanocomposites. The nanofiller used include an aluminosilicate powder having a mean particles size of about 80 nm and 1:4 M ratio of alumina to silica. Advantages - superior hardness, flexible strength, modulus of elasticity, translucency and esthetic appeal, excellent color density, high polish, and polish retention, and excellent handling properties.  (Filtek O supreme Univrasl Restorative Pure Nano O).

Heliometer, microfilled composite resin, a close examination of this composite suggests that a form of nanotechnology was in use years ago, yet never recognized.

Nanosolutions produce unique and dispersible nanoparticles that can be added to various solvents, paints, and polymers in which they are dispersed homogenously. Nanotechnology in bonding agents ensures homogeneity and so the operator can now be totally confident that the adhesive is perfectly mixed every time.
Nanofillers are integrated in the vinylsiloxanes, producing a unique addition siloxane impression material. Better flow, improved hydrophilic properties, hence fewer voids at margin and better model pouring, enhanced detail precision

No comments:

Post a Comment