Includes Definition , Evolution ,Synthesis of nanoparticles , Application of Nanotechnology in Orthodontics ,& its toxicity .

1. Application of NANO Technology in Orthodontics
By
Ashok kumar A
Department of orthodontics
1Dr.Ashok A

2. • Introduction & Definition
• Evolution Of Nanotechnology
• Synthesis Of Nanoparticles
• Nanotechnology In Orthodontics
- Application As Lubricating Agent To Reduce Friction
- Fabrication Of Hollow Wires & SMP
- Fabrication Of Orthodontic Smart Brackets
- Antimicrobial & Enamel Remineralisation Agents
- Nanocomposites And Nanoionomers
- Nanoparticles In Bioimaging
- Nanorobotics & Nanoindenter
- Nanotechnology In AOTM & TAD
• Toxicity In Nanotechnology
• Conclusion & Reference
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2Dr.Ashok A

3. Introduction
• The word Nano is a Greek word, meaning “ dwarf “ (10–9 or one billionth of meter )
• Quantum mechanics - refers to the science of manipulating matter at the level of atoms
measured in billionth of a meter for the production of functional materials and structures in
the range of 0.1–100 nm for their unique properties in application .
NTaniguchi. On the Basic Concept of Nano Technology, Proc ICPE Tokyo 1974; 21:8-23.
Nanotechnology is about manipulating matter, atom by atom
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Why to learn Nanotechnology – Rapidly developing field
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4. Definition
4
Nanotechnology is the production technology to get the extra high accuracy and ultra
fine dimensions, i.e. the preciseness and fineness of the order of 1 nm or10–9 m in length.
- Norio Taniguchi (1974)
Nanoparticles - All the fields or diameters are in the nanoscale range.
Nanomaterials - At least one side or internal structure is in the nanoscale .
-British Standards Institution
Nanodentistry is the science and technology of maintaining near-perfect oral health
through the use of nanomaterials including tissue engineering and nanorobotics .
Balogh L (2010) Why do we have so many definitions for nanoscience and nanotechnology? Nanomed
Nanotechnol Biol Med 6:397–398Dr.Ashok A

5. Evolution of Nanotechnology
.
Richard P Feynman
Prof. K Eric Drexler
Norio Taniguchi
1959 -“There’s plenty of room at the bottom” and explored the possibility
of manipulating materials at the scale of atoms and molecules.
The term nano-technology was first used in 1974- used it to refer
the ability to engineer materials precisely at the nanometer level.
1986 - “Engines of Creation” -proposed the idea of a nanoscale “assembler”
which would be able to replicate and have molecular control .
Sahoo SK., et al. “The present and future of nanotechnology in human health care”.
Nanomedicine: Nanotechnology, Biology, and Medicine 3 (2007): 20-31. 5Dr.Ashok A

6. Classification of Nanomaterials
IonescuMI (2011) Synthesis of One-Dimensional and Two-Dimensional Carbon Based Nanomaterials.
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7. Freitas RA (1999) Nanomedicine. Basic Capabilities, Georgetown. TX: Landes Biosci 1: 345 347.
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8. 8
Fields using
Nanotechnology
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9. Synthesis of Nanoparticles
• Top-down approach: It starts with a bulk material and
then breaks it into smaller pieces using mechanical,
chemical or other form of energy.
• Bottom-up approach: It synthesizes the material from
atomic or molecular species via chemical reactions,
allowing for the precursor particles to grow in size
• Functional approach : This approach has the objective
to produce a nanoparticle with a specific functionality.
SilvaGA(2004) Introduction to nanotechnology & its applications to medicine. SurgNeurol 61:216–220
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10. 10Dr.Ashok A

11. Malam Y, et al(2009) Liposomes and nanoparticles: nanosized vehicles for drug delivery in cancer.
Trends Pharmacol Sci 30(11):592–599 11Dr.Ashok A

12. Nanotechnology in Orthodontics
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13. Application as Lubricating Agent to Reduce Friction
Carbone nitride (CNx) & ZnO
Nickel-phosphorus & tungsten disulfide (WS2)
Diamond-like carbon coating & nitrocarburizing
Molybdenum disulfide
Polysulfone embedded with hard alumina nanoparticles for brackets
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14. • Katz., et al (2008) - self-lubrication coating (IF-WS2) nanoparticles , these nano-sheets at the
interface of two metals under high loads, leads to a very facile sliding there by reducing the
coefficient of friction.
• Similarly stainless steel wires have been coated with a composite coating of Ni-P & WS2
placed by electro less deposition .
• Considering possible toxicity of WS2 , new self-lubricating coatings, in which metals
other than WS2 have been used. Wei et al.(2008) suggested use of Carbone Nitride (CNx)
coatings on stainless steel wires . Similarly Goto M et al.(2013) -coatings of ZnO .
Maheshwari S., et al. “Nano-orthodontics revolutionizing oral health care”. Indian Journal of Oral Sciences 5 (2014)
14Dr.Ashok A

15. Fabrication of orthodontic brackets
• A new material containing hard alumina nanoparticles embedded in polysulfone was
introduced in year 2012 (UC3M) for making orthodontic brackets.
• The rigidity of the material increases the strength of the brackets & also reduces
frictional and mechanical resistance of the brackets to orthodontic wires along with
maintaining the transparency of the brackets.
• Coating with NPs also improve their properties like:
 Titanium dioxide because of its photocatalytic properties
 Ni-P -WS2 nanoparticles to Reduce friction.
 Zno and Cuo nanoparticles for antibacterial properties
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16. Fabrication of Hollow Wires
• Spherical NiTi particles are coated over a textile or a polymer fiber via electrospinning.
Then, the fiber is removed from inside thus producing a hollow wire.
Advantage :
• Possibly reducing the material needed for the wire production.
• They may deliver lighter and more continuous force.
• The bending properties can be customized by inserting another
wire into the hollow core.
NiTi/Ni-TiO2 nanoparticles - ultrasonic spray pyrolysis (USP).
Limitation
Difficult to obtain
PureNiTi particles
Synthesis of NiTi/Ni-TiO2 composite nanoparticles via Ultrasonic Spray Pyrolysis. Materials & Technology Majeric et al. (2015)16Dr.Ashok A

17. Shape memory polymers
• Carbon Nanotubes or Nanofibers & organic-exfoliated Nanoclay are used as fillers.
• SMPs materials have the ability to memorize a macroscopic equilibrium shape and
then be manipulated and fixed to a temporary shape under specific conditions of
temperature and stress.
• Polymers activated by the body temp or by light (photoactive nanoparticles).
• In addition, the SMP materials are clear, colourable,
and stain resistant, providing the patient a more
aesthetically appealing.
Gunes S and Jana C. “Shape memory polymers and their nanocomposites:
a review of science and technology of new multifunctional materials”.
Journal of Nanoscience and Nanotechnology(2008)
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18. Smart brackets with nanomechanical sensors
• Knowledge of the 3D force-moment systems applied for OTM is of utmost importance for
the predictability of the course of tooth movement & reduction of traumatic side effects.
• Nanomechanical sensors can be fabricated and be incorporated
into the base of orthodontic brackets in order to provide real-time
feedback about the applied orthodontic forces.
• Allows the orthodontist to adjust the applied force to be within
biological range to efficiently move teeth with minimal side effects.
Smart bracket for multidimensional force and moment measurement.
J Dent Res 86(1):73–78
Lapaki et al 2007 - “smart” bracket
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19. Nanoparticle delivery
from
Elastomeric ligature
• Elastomeric ligatures can serve as a carrier scaffold for delivery of nanoparticles that can
be anticariogenic,antiinflammatory & antibiotic drug embedded in the elastomeric matrix.
• Wiltshire et.al conclude that the fluoride release from elastomeric ligatures is
characterized by an initial burst of fluoride during the first few days followed by a logarithmic
decrease. For optimum clinical benefit, the fluoride ties should be replaced monthly.
Wiltshire WA. In vitro and in vivo fluride release from orthodonic elastoomerc ligature ties.
Am. J Orthod Dentofac Orthop. 1999; 115(3):288-292. 19
Martin et al Fluoridated
elastomers: effect on the
microbiology of plaque.
AJODO 2004
Fluor-I-Ties
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20. Antimicrobial Agents
• Elaska., et al - Titanium dioxide (TiO2) NPs incorporated GIC
concluded that improved antibacterial and mechanical properties were seen.
• Poosti.,et al, - Titanium dioxide (TiO2) NPs to Orthodontic Composite
enhances its antibacterial effects without compromising the SBS.
• Coating of thin film of nitrogen-doped (TiO2) to Orthodontic Brackets shows
antimicrobial properties - they resist biofilm formation due to increased hydrophilicity.
Nitrogen doped Titanium dioxide (TiO2), Silver (Ag), Gold (Au) , Silica (SiO2)
Copper (Cu/CuO) and ZnO nanoparticles
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21. Enamel Remineralisation (Dental Biomimetics)
• Calcium Nanophosphate crystals, which are less than 100nm, organised in crystalline form
of hydroxyapatite have been developed recently.
• This leads to release of calcium, phosphate and fluoride ions that are organised in
fluorapatite and calcium fluoride on the demineralised surface of tooth
• Carvalho et al. in 2013 - Calcium Nanophosphate Vs CCP-APP Paste
• It was concluded that Ca Nanophosphate is a better remineralizing agent for eroded
enamel surfaces after debonding of orthodontic brackets .
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Increased surface area , Wettability & Increased Bioactivity.
Dr.Ashok A

22. Self-healing Materials
• When a crack appears near the network, the healing fluid (stored in bubbles which can be
incorporated in the material) can flow to the damaged region and fill the fissure.
• This concept can be applied to polymer brackets and archwires. The autopolymerized
monomer can be incorporated in nanosized bubbles & can be integrated with the material.
• Fracture of the bracket or wire would induce bursting of the nanobubbles and exposure of
the monomer to air, thereby resulting in polymerization and filling of the crack- induced gap.
Self-healing and thermo reversible rubber from supramolecular assembly. Nature 451:977–980 22Dr.Ashok A

23. Nanocomposites And Nanoionomers
• Nanoparticles of reduced size are being used as fillers to reduce polymerization
shrinkage and to improve the mechanical properties of strength .
• Uysal et al (2010) - evaluated the bond strength of nanocomposites and nanoionomers
shown that these nanomaterials may be suitable for bonding in orthodontics as they fulfill
the shear bond strength ranges for clinical acceptability
Types of fillers:
• Nanoclusters
• Nanoparticles
Silica nanosized filler
Titanium dioxide and
Nano zirconia
Techniques
Flame pyrolysis,
Flame spray pyrolysis,
Sol–gel processes.
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24. 24Dr.Ashok A

25. Nanoparticles in Bioimaging
Advantage
• Tunable physical (e.g., optical and magnetic)
properties,
• High stability (e.g., against photobleaching),
• Possibility of targeted delivery, and specific
binding via chemical functionalization,
• Multimodality (ability to combine several
functions in one particle),
• High sensitivity, and selectivity.
Bioimaging Techniques
• Optical and confocal microscopy,
• NIR imaging, magnetic resonance
imaging (MRI),
• Computed tomography (CT),
• Positron emission tomography (PET),
• Single-photon emission CT (SPECT),
and ultrasound imaging.
Gun’ko YK (2016) Nanoparticles in bioimaging. Nanomaterials (Basel). 6(6):105 25Dr.Ashok A

26. Nanoindenter
• A nanoindenter coupled with atomic force microscope (AFM) is used to evaluate
nanoscale surface characteristics of bio-materials.
• They have also been used to evaluate mechanical properties such as elastic modulus,
yield strength, fracture toughness, scratch hardness and wear properties.
• This test can be used to evaluate the side effects of orthodontics.
For instance, it is applicable to measure fracture roughness of dental
enamel on the effects of bonding-debonding of bracket .
Ayatollahi MR, Karimzadeh A. Nano-Indentation Measurement of Fracture
Toughness of Dental Enamel. IntJ Fract. 2013; 183(1): 113–118.
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27. NPs in Miniscrews to Prevent Infection of Implants
• The long-term survival or stability of implants primarily depends on the inflammatory
condition that causes peri-implantitis and loss of supporting bone
• The initial colonizers that adhere to tooth and implant surfaces include S.oralis, S. mutans.,
A.actinomycetemcomitans are known to be responsible for many periodontal and peri-
implant diseases .
Silver Nanoparticles (AgNPs) - Provide Large surface area
• Therefore, in the recent past the amalgamation of AgNPs with different biomaterials such as
silver-doped hydroxylapatite, polymer AgNPs, & AgNPs on TiO2 have been developed .
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28. Ideal Mini-Implant Surface Using Nanoparticles
• Currently, TADs are manufactured with smooth titanium surfaces because
• Biocompatible coatings like Titanium nanotubes are studied to evaluate if the nanotubular
layer can enhance initial osseointegration and can serve as an interfacial layer between the
newly formed bone and the TAD.
• To Improve the Primary Stability of TADs
Nanostenciled RGD(Arg-Gly-Asp)-gold patterns
Tricalcium phosphate (TCP) nanocoating
Ultrafine grain-sized titanium (UFG Ti)
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Complete osseointegration is a disadvantage that complicates their removal.
Lack of osseointegration is also one of the factors for the failure of TADs.
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29. To Improve the Stability of the Newly Forming Bone
• Patients with clefts many a times require a bone graft to fill the defects.
• Bioactive and biodegradable poly bioactive glass hydroxyapatite (PBGHA) and poly
bioactive glass nanocomposite coatings have been tested.
• They have an ability to serve as a scaffold or template to guide the newly forming bone
along its surfaces thus promoting its stability.
Fast element mapping of titanium wear around implants of different surface structures.
Clini Oral Implant Res 17(2):206–211
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30. Bio MEMS/NEMS for Orthodontic Tooth Movement &
Maxillary Expansion
Bio-MEMS (Biomedical Microelectro mechanical systems): It is defined as the science
and technology of operating at the microscale for biological and biomedical
application,which may or may not include any electronic or mechanical functions.
NEMS (Nanoelectro mechanical systems): These are devices integrating electrical and
mechanical functionality on the nanoscale level.
• Concept - Animal experiments indicated that when 15–20 μA of low direct current
(DC) was applied to the alveolar bone to modifying the bioelectric potential
osteoblasts and PDL cells --increased concentrations of the second messengers, cAMP
and cGMP, leads to accelerated bone remodeling
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31. • An enzymatic micro battery when placed on the gingiva near the alveolar bone might
be a possible electrical power source for accelerating orthodontic tooth movement.
• It is proposed that this device uses organic
compound (glucose) as the fuel and it is
noninvasive & non-osseointegrated .
• The enzyme battery is fabricated with
the combination of two enzyme electrodes and
biocatalysts such as glucose oxidase or
formate dehydrogenase to generate electricity .
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32. • However, there are several issues like soft tissue biocompatibility, effect of food with
different temperature and pH range on the output of such microfabricated enzyme
battery that need to be addressed .
• Nanotechnology has offered nanostructured conductive materials , the large surface area
of these nanomaterials can increase the enzyme loading and facilitate reaction
kinetics, and thus improve the power density of the biofuel cells.
• It is expected that the MEMS/NEMs based system will be applied over the next few years
to enhance orthodontic tooth movement.
Microfabricated biocatalytic fuel cells: A new approach to accelerating the orthodontic tooth movement.
Med Hypotheses 73(3): 340-341. 32Dr.Ashok A

33. Nano -LIPUS devices
Ultrasound is a form of mechanical energy that is transmitted through and into
biological tissues as an acoustic pressure wave at frequencies above the limit of human
hearing, is used widely in medicine as a therapeutic, operative, and diagnostic tool .
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34. • The device will be easily mounted on a bracket or a plastic removable crown. An
energy sensor can also be used that will ensure the LIPUS power is reaching the target
area of the teeth roots within the bone.
• LIPUS - Enhance bone growth into Ti porous–coated implants for osseointegration and
bone healing after fracture and after mandibular DO and has also used for stimulating
mandibular cartilaginous growth.
• Based on the observation that LIPUS can promote dental tissue formation in rabbits,
El Bialy et al. concluded that it may also be used to treat root resorption.
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35. Nanorobotics- Futuristic Approach
• Nanorobotics are self-sufficient machines which are functional at the nanoscale.
• The use of nanorobotics in medical applications are like drug delivery, management of
aneurysms, and tumors.
• Frietas et al.(2000) suggested that dental nanorobots can be utilized to induce oral
anesthesia by an onboard nanocomputer that executes preprogrammed instructions and can
be delivered as a colloidal suspension containing millions of active analgesic micrometer-
sized nanorobot particles on the patient’s gingiva.
Shetty NJ, Swati P, David K. Nanorobots: Future in dentistry.
Saudi Dent J. 2013; 25(2): 49–52.
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36. • More futuristic applications have been proposed by Frietas et al on utilizing nanorobots to
treat carious lesions, dentin hypersensitivity, and dentifrobots (nanorobots in dentifrices).
• These could be delivered through mouthwash or toothpaste and could patrol supra- and
subgingival surfaces of teeth, performing continuous plaque/calculus removal and
metabolizing trapped organic matter into harmless and odorless vapor.
• The theory of its use extended to orthodontics in distant future, where nanorobots with
specific motility mechanisms would navigate through periodontium to remodel it
directly allowing accelerated orthodontic tooth movement.
36
Shetty NJ, Swati P, David K. Nanorobots: Future in dentistry.
Saudi Dent J. 2013; 25(2): 49–52.
Dr.Ashok A

37. Toxicity
• The rapid developments in the field of nanotechnology also bring with them the concerns
related to toxicity through new sources of exposure like inhalation, ingestion, & injection.
• Nanomaterials have unique physicochemical properties, such as ultra-small size, large
surface area to mass ratio, and high reactivity and these properties also influence and
determine the biological responses and can often lead to toxicity.
• Ag NPs can enter via the blood-brain barrier and accumulate in different regions of the
brain and this may be beneficial for drug delivery, but at the same time can increase a risk to
the patient.
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38. • Cross the transplacental membrane or cross
the peritoneal cavity into uterus and may
affect the cranial development of embryo.
• Ag NPs is associated with the depletion of
glutathione level, increased level of ROS.
• Cu NPs are often metabolized in liver and
are reported to have toxic effects to hepatic
and renal tissues
• Au NPs are also associated with affecting
male sterility .
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39. Summary & Quick Review
Lubricating agents to reduce friction
Katz., et al (2008) (IF-WS2) ,Wei et al.(2008) (CNx), Goto M et al.(2013) –(ZnO)-Wires
Polysulfone embedded hard alumina NPs (2012) by UC3M -Orthodontic brackets
Fabrication Orthodontic wires
Majeric et al. (2015)-Fabrication of Hollow Wires - NiTi/Ni-TiO2 NPs
Lan X et al.(2011) -Shape memory polymers -Nanotube, Nanoclay
Fabrication of Orthodontic Smart brackets
Lapaki et al 2007 -To provide real-time feedback about the applied orthodontic forces.
Anticariogenic
Martin et.al (2004)- The fluoride NPs release from Elastomeric Ligatures (Fluor-I-Ties)
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40. Antimicrobial Agents
Lin., et al.- RMGIC with Nano Fluorapatite
Elaska., et al - Titanium dioxide incorporated GIC
Poosti., et al - Titanium dioxide orthodontic composite
Farahani AB., et al. - Titanium dioxide orthodontic brackets
Enamel Remineralizing Agents - Medeiros et al(2014).- Calcium Nanophosphate
Self-healing Materials-Cordier et al (2008)-Autopolymerized nanosized monomer bubbles
Nanocomposites And Nanoionomers -Uysal et al (2010) -TiO2 , Nano Zirconia
Nanoparticles in Bioimaging Gunko YK (2016) - Nanoparticles bioimaging contrast agents
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41. Nanoindenter – Ayatollahi(2013) Hardness, Elastic Modulus,Yield Strength, Fracture Toughness
Nanoparticle in Mini-implants
Colon G et al(2006) Prevent Infection of Implants -AgNPs
Meyer et al(2006) -Ideal Mini-Implant Surface - Titanium nanotubes
Accelerating orthodontic tooth movement
Davidovitch et al (2009) - Bio MEMS/NEMS.
Rosenfeld (2004) - Nanorobotics
Enchance bone growth,bone healing, A.orthodontic tooth movement ,root resorption
El-Bialy et al (2006) - Nano -LIPUS devices
41Dr.Ashok A

42. Conclusion
• A lot of research is being focused on the application of nanotechnology in orthodontics.
Though much of the research has taken place in the labs, gradually in vivo studies are
making their way.
• Biosafety of nanoparticles and materials is a subject of concern, demanding focus on further
studies of the toxic effects of nano-particles to ensure their ethical usage in the oral cavity.
• The future in orthodontic treatment will benefit enormously through nanotechnology , should
all the current attempts succeed to its clinical application at a reasonable cost to the
orthodontist and patients.
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43. REFERANCE
• NTaniguchi. On the Basic Concept of Nano Technology, Proc ICPE Tokyo 1974; 21:8-23.
• Shetty NJ, Swati P, David K. Nanorobots: Future in dentistry.Saudi Dent J. 2013; 25(2): 49–52.
• Fast element mapping of titanium wear around implants of different surface structures. Clini Oral
Implant Res 17(2):206–211
• Malam Y, et al(2009) Liposomes and nanoparticles: nanosized vehicles for drug delivery in cancer.
Trends Pharmacol Sci 30(11):592–599
• Freitas RA (1999) Nanomedicine. Basic Capabilities, Georgetown. TX: Landes Biosci 1: 345 347.
43Dr.Ashok A

44. • Microfabricated biocatalytic fuel cells: A new approach to accelerating the
orthodontic tooth movement. Med Hypotheses 73(3): 340-341.
• Self-healing and thermoreversible rubber from supramolecular assembly. Nature
451:977–980
• Katz et al. (2008) Improved orthodontic stainless steel wires coated with inorganic
fullerene-like nanoparticles of WS2 impregnated in electroless nickel– phosphorous
film. Dent Mater 24(12):.
• Fast element mapping of titanium wear around implants of different surface
structures. Clini Oral Implant Res 17(2):206–211
44Dr.Ashok A

45. 45Dr.Ashok A