Definition :
“The creation of functional materials, devices and systems through control of matter on
the nanometer scale (1-100 nm), and exploitation of novel phenomena and properties (physical, chemical and biological) at that length scale”.
-Indian Journal of Multidisciplinary Dentistry, Vol. 1, Issue 5, July-August 2011
Introduction
Ò The term “Nanotechnology” was coined by Prof. Kerie E.Drexler
Ò «Nano»-the Greek word - “dwarf”.
Ò Nanotechnology- science of manipulating matter measured in the manometer, roughly the size of 2 or 3 atoms
Ò The basic idea of nanotechnology- to employ individual atoms and molecules to construct functional structures.
Ò The late Nobel Prize winning physicist Richard P. Feynman in his historic lecture in 1959,
“this is a development which I think cannot be avoided”
Classification
1.Nanoelectronics
2.Nanomaterials/particles
3.Nanobiotechnology
Nanoelectronics :
Ò Use Of nanotechnology on electronic components,especially transistors,computer processors etc.
Nanomaterials :
Ò Essentially Polymers Reinforced by nanoparticles
Ò Results in novel materials –used as light weight replacements for metal
Ò Can affect the mechanical properties like Stiffness or elasticity
The various nanoparticles are
Ò 1. Nanopores
Ò 2. Nanotubes
Ò 3. Quantum dots
Ò 4. Nanoshells
Ò 5. Dendrimers
Ò 6. Liposomes
Ò 7. Nanorods
Ò 8. Fullerenes
Ò 9. Nanospheres
Ò 10. Nanowires
Ò 11. Nanobelts
Ò 12. Nanorings
Ò 13. Nanocapsules
Classification of Nanomaterials :
1.Carbon based
2.Metal based
3.Dendrimers
4.Composites
Ò Nano assemblers –smaller than cell nucleus
Ò Potential
Ò Customisation of diagnosis and treatment
Nanodiagnostics –
is the use of nanodevices for the early disease identification or predisposition at cellular and molecular level
in-vitro diagnostics,
Ò increase the efficiency and reliability of the diagnostics
Ò uses human fluids or tissues samples by using selective nanodevices, to make multiple analyses at subcellular scale
In vivo diagnostics,
Ò devices able to work inside the human
1.to identify the early presence of a disease,
2. to identify and quantify toxic molecules, tumor cells
NANODENTISTRY
Ò maintenance of comprehensive oral health by employing nanomaterials, including tissue engineering, and ultimately,dental nanorobots.
Ò 1.local anaesthesia,
Ò 2. dentitionrenaturalization, and permanent hypersensitivity cure,
Ò 3.Complete orthodontic realignments during a single office visit,
Ò 4. covalently bonded diamondised enamel,
Ò 5. continuous oral health maintenance using mechanical dentifrobots
Nanomaterials in dentistry
1.Nano composites
2.Nanosolution
3.Impression materials
4.Nanoencapsulation
5.Local nanoanesthesia
6.Dentinal hypersensitivity
7.Tooth durability and appearance
8.Orthodontic treatment
Uses of Nanomaterials in dentistry:
Ò Nano impression materials
Ò Nano bonding agents
Ò Nano drug releasing systems
Ò Nano composites
Ò Nano Ceramics
Ò Nano Sterilizing agents
Ò Dental implants
Nanocomposites :
Ò nonagglomerated discrete nanoparticles that are homogeneously distributed in resins or coatings to produce nanocomposites
Ò The nanofiller used is
Ò aluminosilicate powder having a mean particle size of 80 ran
Ò a 1:4 M ratio of alumina to silica and
Ò a refractive index of 1.508.
Advantages:
• Superior hardness
• Superior flexural strength, modulus of elasticity andtranslucency
• 50% reduction in filling shrinkage
• Excellent handling properties
Nanosolution:
Ò Nanosolutions produce unique and
dispersible nanoparticles, which can be used in bonding agents.
Ò Ensures homogenecity and ensures that the adhesive is perfectly mixed everytime
Nanoencapsulation
Ò targeted release systems that encompass nanocapsules including novel vaccines, antibiotics and drug delivery with reduced side effects
Ò targeted delivery of genes and drugs to human liver -developed by Osaka University in Japan 2003
Ò Engineered Hepatitis B virus envelope L particles were allowed to form hollow nanoparticles displaying a peptide that is indispensable for liver-specific entry by the virus in humans.
Ò Future specialized nanoparticles could be engineered to target oral tissues, including cells derived from the periodontium
Local nanoanaesthesia
Ò colloidal suspension containing millions of active analgesic micron-size dental robots will be instilled on the patient’s gingiva.
Ò After contacting the surface of crown or mucosa,the ambulating nanorobots reach the pulp via the gingival sulcus, lamina propria and dentinal tubules
Ò Once installed in the pulp, the analgesic dental robots may be commanded by the dentist to shut down all sensitivity in any particular tooth that requires treatment.
Ò After oral procedures are completed, the dentist orders the nanorobots to restore all sensation, to relinquish control of nerve traffic and to egress from the tooth by similar pathways used for ingress
Dental hypersensitivity
Ò Natural hypersensitive teeth have eight times higher surface density of dentinal tubules and diameter with twice as large than nonsensitive teeth.
Ò Reconstructive dental nanorobots, using native biological materials, could selectively and precisely occlude specific tubules within minutes, offering patients a quick and permanent cure
Tooth durability and appearance
Ò 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.
Ò 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 continuous calculus debridement.
Orthodontic treatment :
Ò Orthodontic nanorobots could directly manipulate the periodontal tissues, allowing rapid and painless tooth straightening, rotating and vertical repositioning within minutes to hours
Nanotechnology in Dental Implants:
Ò Coating of nanoparticles over the dental implants.
Ò The surface of the implant plays a critical role in determining biocompatibility and biointegration because it is in direct contact with the tissues.
Ò Implant surface composition
Ò surface energy
Ò surface roughness
Ò surface topography
-the four material related factors which can influence events at bone-implant interfaces.
Ò Surface textures are of three types- macro, micro and nano
Ò Nanostructured (NS) materials contain a large volume fraction (>50%) of defects such as grain boundaries, inter phase boundaries, and dislocations, and this strongly influences their chemical and physical properties.
Ò Biomimetic dental implants may be the next development in the field.
Ò Coating implants with nanotextured titanium, hydroxy apatite, and pharmacological agents such as bisphosponates –
1. may induce cell differentiation and proliferation and
2. may promote greater vascularity in highly cortical bone,
-improves conditions for early and long-term
Ò (in response to functional loading) bone remodeling
Ò Successful osseointegration is influenced by both the chemical composition and the surface geometry or topography of the implant
Ò Surface nanotopography affects cell interactions at surfaces and alters cell behavior when compared to conventional sized topography
Ò Nanoscale topography is a powerful way of altering protein interactions with the surface.
Methods of Synthesis of Implant Nanomaterials:
1.Top down 2.Bottom up
Top down: Produced from larger structures by use of ultrafine grinders,lasers and vaporisation followed by cooling
Bottom up: Arranging molecules to form complex structures with new and useful properties
Imaging of nanomaterials:
Ò X-ray diffraction[XRD]
Ò Atomic force microscopy[AFM]
Ò Scanning electron microscope[SEM]
Ò Transmission electron microscopy[TEM]
Ò Magnetization measurements
Ò Nuclear magnetic reasonance[NMR]
Ò Spectroscopy
Ò 2-D electrophoresis and Mass spectrometry of proteins
Ò Confocal Microscopy
Nanobiotechnology :
Ò Nanorobotics
Nanorobots are theoretical microscopic devices measured on the scale of nanometers (1 nm equals one millionth of 1 mm).
Hazards of nano :
Ò The potential deleterious effect analyzed so that expanded development and use
Ò of nanotechnology can proceed.
Ò rapid withdrawal of a nanotechnology-based
Ò product, Magic Nano, a spray-on ceramic sealant to repel dirt.
Ò Over 110 consumers in Europe reported respiratory symptoms after using the spray.The product was withdrawn in March 2006.
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