Biomimeting agents are those which gives the dentist the power to work flawlessly and the patient recieves a life like result and working. It is the most discussed topics in the dental world at this time and indeed the most interesting too.

1. Guided by : Dr S. Prakasam Presented by:
Dr K.C. Ponnappa Dr.Supratim Tripathi
TOOTH CARE DENTAL CLINIC
LUCKNOW, UTTTAR PRADESH.
INDIA. 7800302984

2. Biomimetcs

3. Biomimetic dentistry
Properties of biomaterials
Amalgam
Gold alloys
Composite resins
Glass ionomer
Ceramics
Articles
References

5. What is biomimetic dentistry?
Biomimetic dentistry, a type of tooth
conserving dentistry, treats weak,
fractured, and decayed teeth in a way
that keeps them strong and seals them
from bacterial invasion.

6. • Biomimetic means to copy or mimic nature.
• Nature is our ideal model to imitate. In order to mimic
nature we must understand what nature looks like or
feels like. We need to know how it moves or behaves.
In other words, we can study nature's properties so
that we can better duplicate it.
>> 0 >> 1 >> 2 >> 3 >> 4 >>

7. • Biomimetic dentistry is conservative.
• One more important aspect about
biomimetic dentistry needs to be
addressed:
 less dentistry is the best dentistry; we can
even say no dentistry is the best dentistry.
 Much of the surgical aspect of dentistry
can be eliminated or prevented with
modern science.
 Periodontal disease and caries (decays)
can practically be eliminated with Ozone
treatment, hygiene, and properly placed
pit and fissure sealants.
 If caries or old fillings are existing, they
can be treated with the most conservative
materials and techniques.
 We can say that preservation and
conservation lie at the heart of biomimetic
dentistry.
 It is a win-win situation for everyone.
Page 7

8. (Biomimicry)
• Biomimics take clues from nature
• Biomimicry (from bios, meaning life, and
mimesis, meaning to imitate) is a design
discipline that studies nature‟s best ideas
and then imitates these designs and
processes to solve human problems.
• Bionics (short for Biomechanics) (also
known as
biomimetics, biognosis, biomimicry, or
bionical creativity engineering) is the
application of methods and systems found in
nature to the study and design of
engineering systems and modern Page 8

9. Biology

10. High fuel efficiency concept vehicle
Based on the Body Shape of Boxfish
Bionic car, 20 percent lower fuel
consumption and up to 80 percent
lower nitrogen oxide emissions
photo courtesy of DaimlerChrysler

11. Mollusk-inspired Fan: Energy
Saver and Reduction of Noise

12. Cricket-Inspired Hearing Aid

13. Beetle-inspired Material for
water harvester: the patterning
New material that copies the properties of
the wing surface of the Namibian desert
beetle for collecting precious drinking
water from an invisible mist. Inventa
Partners: Air Conditioning for recycling
water. 2004 (Original research by MIT)

14. Eys of Moth to Autoflex MARAG
(MothEye Anti-Reflective, Anti-
Glare)
These compound eye structures have
evolved to collect as much light as
possible without reflection, in order to
prevent moths being detected by night
time predators. Applications include flat
panel displays, touch screen interfaces,
electroluminescent lamps and lenses for
mobile phones and PDAs.

15. Biologically inspired robots
Six legged robot at the AI Lab, Univ. of
Quadruped Walking Machine to Climb Slopes at the Univ. of Michigan
Nagoya, Japan
http://www.ai.mit.edu/
projects/leglab/home.
html
Fully Contained 3D Bipedal Walking Dinosaur Robot at
MIT Snake-like – by Mark Tilden

16. Smart Toys
Honda‟s
Sony‟s
Asimo
SDR3
AIBO - Sony 2nd Generation ERS-210 I-Cybie

17. Robot that responds to human
expressions
Cynthia Breazeal and her robot Donna

18. Applications of biomimetic robots
Mattel‟s Miracle
Moves Baby doll
making realistic
behavior of a baby.
Walking forest machine for complex
harvesting tasks (Plustech Oy,
Finland).
[http://www.plustech.fi/Walking1.htm
l]
Multi-limbed robots
LEMUR (Limbed
Excursion Mobile
Utility Robot) at JPL.

19.  Romans and Chinese used gold in dentistry over
2000 years ago.
 Ivory & wood teeth
 Aseptic surgery 1860 (Lister)
 Bone plates 1900, joints 1930
 Turn of the century, synthetic plastics came into
use
 1960- Polyethylene and stainless steel being used
for hip implants

20. BACKGROUND
 Historically, biomaterials consisted of materials
common in the laboratories of physicians, with
little consideration of material properties.
 Early biomaterials :
 Gold: Malleable, inert metal (does not oxidize); used in dentistry by Chinese,
Aztecs and Romans--dates 2000 years
 Iron, brass: High strength metals; rejoin fractured femur (1775)
 Glass: Hard ceramic; used to replace eye (purely cosmetic)
 Wood: Natural composite; high strength to weight; used for limb prostheses
 and artificial teeth
 Bone: Natural composite; uses: needles, decorative piercings

21. INTRODUCTION
 A biomaterial
 is a nonviable material used in a medical device, intended to interact
with biological systems.
 is used to make devices to replace a part of a function of the body in a
safe, reliable, economic, and physiologically acceptable manner.
 is any substance (other than a drug), natural or synthetic, that treats,
augments, or replaces any tissue, organ, and body function.
 The need for biomaterials stems from an inability to treat many diseases,
injuries and conditions with other therapies or procedures :
 replacement of body part that has lost function (total hip, heart)
 correct abnormalities (spinal rod)
 improve function (pacemaker, stent)
 assist in healing (structural, pharmaceutical effects: sutures, drug
release)
Williams, D.F. (1987) Definitions in Biomaterials. Proceedings of a Consensus Conference of the European Society
For Biomaterials, England, 1986, Elsevier, New York.

22. Muhammad Wasim Akhtar

23.  Metals
 Stainless Steel
 Cobalt-Chromium alloys
 Titanium alloys
 Ceramics
 Alumina
 Zirconia
 Oxinium
 Polymers
 Polymethylmethacrylate
 Polyethylene

24. Drug Delivery Skin/cartilage
Devices
Polymers Ocular
implants
Orthopedic Bone
screws/fixation replacements
Heart
valves
Metals Synthetic Ceramics
BIOMATERIALS
Dental Implants Dental Implants
Semiconductor
Materials Biosensors
Implantable
Microelectrodes

25. Mechanical
Properties Of
Materials
 Ductility DUCTILITY
ELASTICITY
 Elasticity
 Hardness
 Tensile Strength
HARDNESS TENSILE STRENGTH

26. Structural biological materials
Hard Tissues: Bone, enamel, dentin
Soft Tissues: Cartilage, tendon,
ligament, vitreous
humor,vasculature,skin, organs
Fluids: Blood, synovial fluid
Problems when used as an implant
material: Infection, resorption,
inflammation, rejection

27. Synthetic Biomaterial Classes
• METALS: Co-Cr alloys, Stainless steels, Gold, Titanium
alloys, Vitallium, Nitinol (shape memory alloys).
Uses: orthopedics, fracture fixation,dental and facial
reconstruction, stents.
• CERAMICS: Alumina, Zirconia, Calcium Phosphate,
Pyrolitic Carbon.
Uses: orthopedics, heart valves, dental reconstruction.
• COATINGS: Bioglasses, Hydroxyapatite, Diamond-like
carbon, polymers.

28. Biomaterial Classes cont.
• POLYMERS: Silicones, Gore-tex (ePTFE),
polyurethanes,
polyethylenes(LDPE,HDPE,UHMWPE,), Delrin,
polysulfone, polymethylmethacrylate.
Uses: orthopedics, artificial tendons,catheters,
vascular grafts, facial and soft tissue reconstruction.
• HYDROGELS: Cellulose, Acrylic co-polymers.
Uses: drug delivery, vitreous implants,wound healing.
• RESORBABLES: Polyglycolic Acid, Polylactic acid,
polyesters.
Uses: sutures,drug delivery, in-growth, tissue
engineering.

29. Restorative and Esthetic Materials
• Restorative: To replace or bring
something back to its natural
appearance and function.
• Esthetic: To replace or bring
something back to its pleasing
appearance.
Page 29

30. Restorations
• Restorative materials that are
applied to the tooth while the
material is pliable and able to carve
and finish.
– Amalgam
– Gold alloys
– Composite resins
– Glass ionomer
– Ceramics
Page 30

31. Amalgam
 HISTORY :
 Dental amalgam is one of the oldest filling
materials in use today. It is available to
dental profession for over 150 years.
 The first dental silver amalgam was
introduced into England by “Joseph Bell” in
1819 and was known as “BELLS PUTTY”.
 - SIR REGNART because of his extensive
study is considered as the FATHER OF
AMALGAM.

32. 32

33. • First Amalgam War :
• In 1843 American Society of Dental Surgeons
condemned the use of all filling material other than gold
as toxic, thereby igniting “first amalgam war‟. The society
went further and requested members to sign a pledge
refusing to use amalgam.
• Second Amalgam War :
• In mid 1920‟s a German dentist, Professor A.Stock
started the so called “second amalgam war”.
• He claimed to have evidence showing that mercury could
be absorbed from dental amalgam which lead to serious
health problems.
• He also expressed concerns over health of dentists,
stating that nearly all dentists had excess mercury in
their urine.

34. • Third Amalgam War ;
• The current controversy, sometimes termed as
“Third Amalgam War‟ began in 1980 primarily
through the seminars and writings of Dr.Huggins,
a practicing dentist in Colarado.
• He was convinced that mercury released from
dental amalgam was responsible for human
diseases affecting the cardiovascular system and
nervous system.
• He also stated that patients claimed recoveries
from multiple sclerosis, Alzhemer‟s disease and
other diseases as a result of removing their
dental amalgam fillings.

35. • PRESENT :
• Classification (Marzouk) :
• The amalgam alloy can be classified in the following ways :
• According to number of alloy metals :
• Binary alloys (Silver-Tin)
• Ternary alloys (Silver-Tin-Copper)
• Quaternary alloys (Silver-Tin-Copper-Indium).
• According to whether the powder consist of unmixed or admixed
alloys.
• Certain amalgam powders are only made of one alloy. Other have one
or more alloys or metals physically added (blended) to the basic alloy.
eg. adding copper to a basic binary silver tin alloy.
• According to the shape of the powdered articles.
• Spherical shape (smooth surfaced spheres).
• Lathe cut (Irregular ranging from spindles to shavings).
• Combination of spherical and lathe cut (admixed).
•
• According to Powder particle size.
• Microcut
• Fine cut
• Coarse cut
Page 35

36. • According to copper content of powder
• Low copper content alloy – Less than 4%
• High copper content alloy – more than 10%
• According to addition of Nobel metals.
• Platinum
• Gold
• Palladium
• According to compositional changes of succeeding generations of
amalgam.
• First generation amalgam was that of G.V.Black i.e. 3 parts silver one part
tin (peritectic alloy).
• Second generation amalgam alloys - 3 parts silver, 1 part tin, 4% copper to
decrease plasticity and increase hardness and strength. 1% zinc, as
oxygen scavenger and decrease brittleness.
• Third generation : First generation + Spherical amalgam .
• Fourth generation : Adding copper upto 29% to original silver and tin
powder to form ternary alloy. So that tin is bounded to copper.
• Fifth generation : Quaternary alloy ie.. silver tin and copper and indium.
• 6th generation (Eutectic alloy ).
Page 36

37. • According to Presence of zinc.
• Zinc containing (more than 0.01%).
• Non zinc containing (less than 0.01%).
• CLASSIFICATION ACCORDING TO STURDEVENT
• According to Sturdevant amalgam is classified into :
• Amalgam alloy particle according to geometry and size.
• Copper content
• Zinc content
•
• 1) Amalgam alloy particles according to Geometry and
size :
• A) Irregular powder particles (lathe cut) : In these more
mercury is needed to fill the spaces between the particles.
Mercury is later removed by wringing the mass in a squeeze
cloth.
• B) Spheroidal alloy particles.
Page 37

38. • 2) Copper content :
• A) High Copper (More than 11.9% to
28.3%)
• B) Low copper (2.4% to 8.6%)
• 3) Zinc content
• A) Zinc containing
• B) Zinc free
Page 38

39. • STAGES OF DIMENSIONAL
CHANGES :
• Dimensional Changes occurs in 3
stages :
• Stage I : Called initial contraction
for approximately 20 minutes after
beginning of trituration. It results
from absorption of mercury, into
interparticular spaces of alloy
powder.
• Stage II : Called as expansion
stage. This is due to formation
and growth of matrix crystals.
• Stage III : Called as limited
delayed contraction. This occurs
due to absorption of unreacted
mercury.
Page 39

40. Indications for
Using Amalgam
 In individuals of all ages.
 In stress-bearing areas of the
mouth.
 When there is severe destruction
of tooth structure.
 As a foundation.
 When personal oral hygiene is
poor.
 When moisture control is
problematic.
 When cost is an overriding patient
concern.

41. Indications for
Not Using Amalgam
 Esthetics is important.
 Patient has a history of allergy to
mercury or other amalgam components.
 The cost of other restorative materials
or treatment options is not a factor.

42. Chemical Makeup of Amalgam
• Mercury (43% to 54%)
• Alloy powder (57% to 46%)
– Silver, which gives it its
strength.
– Tin for its workability and
strength.
– Copper for its strength and
corrosion resistance.
– Zinc to suppress oxidation.
Page 42

43. Issues Concerning Amalgam
 Harm to patients: Essentially
harmless.
-The exception is with patients who
have many amalgam restorations, or a
high sensitivity to metals.
 Harm to Dental Personnel:
- Health concerns with high exposure to
mercury, not amalgam.
 Tremors
 Kidney dysfunction
 Depression
 Nervous system disorders

44. Amalgam Hygiene
 Do not contact mercury with your
skin.
 Protect against spillage during
trituration.
 Keep lid closed during
trituration.
 Do not discard scrap amalgam into
waste containers.
 Collect all scrap amalgam and
store under water or photographic
fixer solutions in a closed
container.

45. Preparation of Amalgam
 Capsules (600 mg of alloy):
 For small or single-surface
restorations.
 Capsules (800 mg of alloy): For
larger restorations.
 Trituration: The process by
which the mercury and alloy are
mixed together to form the mass
of amalgam.

46. Direct Application
of Amalgam
1. Mixed amalgam placed in amalgam
well.
2. Amalgam carried to the prepared
tooth.
3. Amalgam placed in increments in
the prepared tooth.
4. Each increment is condensed
immediately.
5. Carvers are used to carve
anatomy into the amalgam.
6. A burnisher is used to smooth
the amalgam.
7. The new restorations occlusion
is checked.

47. RECENT ADVANCES IN DENTIN AMALGAM :
Fluoride Containing Amalgam :
Secondary caries is one of the most important
cause of failure in amalgam restoration. This was
considerably low in case of silicate cement which
was associated with the high fluoride content of
that material. The addition of fluoride to amalgam
was therefore attractive way to stimulate the
anticariogenic properties of silicate cement.
Stannous fluoride was added
Results / Advantages :
Studies showed that there was reduced solubility
of enamel adjacent to fluoride containing
amalgam.
One study has shown that there was lower
incidence of secondary caries around the fluoride
containing amalgam restoration.

48. • Disadvantages :
• Invitro studies have shown that there
is reduction in mechanical properties
such as compressive strength and
corrosion resistance when stannous
fluoride is added to the amalgam.
• INDIUM :
• The possibility of adverse effects
caused by exposure to mercury
vapour caused researchers to
experiment with alternative materials.
• Indium was incorporated into the
amalgam structure to minimize the
vaporization of mercury from the
amalgam surface.
• Effects :
• These Are :
• Total reduction in the amount of
mercury present.
• More efficient oxidation of the surface
of mercury releasing phase.
• It is good wetting agent and adapts
well to tooth surface.
Page 48

49. • GALLIUM ALLOYS :
• Silver amalgam, though an accepted
restorative material, yet the mercury
controversy limits it use. The toxic
effects of mercury coupled with
problems of mercury hygiene, led the
researchers think of mercury free
alloys.
• Biological Considerations :
• Biologically, the results are not
promising. In early gallium alloys,
surface roughness, marginal
discoloration and fracture were
reported. With the improvement in
composition these defects were
significantly reduced but not totally
eliminated.
Page 49

50. • BONDED AMALGAM
RESTORATIONS :
• To overcome one of the major
disadvantage of silver i.e. it does not
adhere properly to cavity
walls, adhesive systems designed to
bond amalgam to enamel and dentin
have been introduced.
• Some studies also suggest that the
use of dual-cured filled liners may be
beneficial for bonding amalgam to
dentin.
• The use of a self-cured filled adhesive
liner has been shown to be as
valuable under amalgam restorations
as under composite restorations.
• Another advantage from the use of
dentin adhesives under amalgam
restorations is that the residual tooth
structure becomes more resistant to
fracture than when teeth are restored
with a copal varnish and amalgam.
Page 50

53. • At present, the benefit of a bonded amalgam is two-fold:
• 1. The reduction or elimination of microleakage afforded by sealing
the prepared tooth structure with a bonding system.
• 2. The reinforcement of the remaining tooth structure.
• STEPS (steps 1 to 4 are common to the technique used for
composite restorations)
• 1. Etch enamel and dentin for 15 seconds
• 2. Rinse, leave moist
• 3. Apply two consecutive coats of Single Bond
• 4. Gently air dry to evaporate the ethanol solvent
• 5. Dispense a small amount (2-3 clicks) of Rely X ARC from the
Clicker dispenser and mix it on a paper pad with a spatula
• 6. Brush it on the preparation for 15 seconds
• 7. Insert and condense the amalgam
• Am J Dent 1993;6:173-5

54. GOLD ALLOYS
• Noble metals:
• The periodic table of elements shows eight noble
metals
• Gold (Au)
• Platinum (Pt)
• Palladium (Pd)
• Rhodium (Rh)
• Ruthenium (Ru)
• Iridium (Ir)
• Osmium (Os)
• and Silver (Ag)

55. • Pure gold (Au) is a soft, malleable, ductile metal that has a
rich yellow colour with a strong metallic luster.
Au - 79 Atomic No.
196.97 Atomic Mass
19.32 gm/cm3 Density
1064.4 C Melting point.

56. Alloy types by function (ISO 1562-
year 2002)
Type Yield str Min Elongtn % Use
MPa (Min)
Type I 80 18 Very low stress
Low strength inlays.
Type II 180 10 Moderate stress
Medium strength inlays, onlays & Full
crowns.
Type III 270 5 High stress onlays,
High strength thin coping, crowns
& saddles
Type IV 360 3 Very high stress
Extra strength saddles, bars, clasps,
partial dentures
frameworks.

57. Composite Resins
• Becoming the most widely
accepted material of choice by
dentists and patients because of
their esthetic qualities and new
advances in their strength .
• Since the 1990‟s resin-based
composite [RBC] sales have
increased. The ability to mimic
tooth structure gives RBC a
distinct advantage for patients
and dental professionals. As
differences between amalgam
and RBC properties
narrowed, resin –based materials
was placed in larger
preparations.
Page 57

58. Class of composite Particle size Clinical use
Traditional 1-50 m glass High-stress areas
(large particle)
Hybrid (1) 1-20 m glass (2) 0.04 High-stress areas
(large particle) m silica. requiring improved
polishability (classes I, II,
III, IV)
Hybrid (midifiller) (1) 0.1-10 m glass (2) High-stress areas
0.04 m silica requiring improved
polishability (classes III,
IV)
Packable hybrid Midifiller/minifiller Situations in which
hybrid, but with lower improved condensability
filler fraction is needed (class I, II)
Flowable hybrid Midifiller hybrid, but with Situations in which
finer particle size improved flow is needed
distribution and /or where access is
difficult (class II) as
gingival increment or
liner.

59. Resins supplied in a syringe.

60. Indications for Using Composite Resins
• Withstand the environments of the
oral cavity.
• Be easily shaped to the anatomy of
a tooth.
• Match the natural tooth color.
• Be bonded directly to the tooth
surface.
Page 60

61. Chemical Makeup of Composite Resins
• Resin matrix
– Dimethacrylate, referred to as BIS-GMA
• Monomer used to make synthetic resins
– Polymerization additives
• Allow the material to take form through
a chemical process
• Initiator
• Accelerator
• Retarder
• Ultraviolet (UV) stabilizers
Page 61

62. Chemical Makeup of Composite Resins cont’d
• Fillers Add the strength and characteristics
necessary for use as a restorative material.
• Inorganic fillers
– Quartz
– Glass
– Silica
– Colorants
• A coupling agent strengthens the resin
by chemically bonding the filler to the
resin matrix.
– Organosilane compound
Page 62

63. Direct Application of Composite
Resins
1. Select the shade of the tooth.
2. Express the needed amount of
material onto the treated pad
or in the light-protected well.
3. Material placed in increments.
4. Material is light-cured.
5. Material is finished and
polished.
Page 63

64. Steps in Finishing a Composite
Restoration
1. Reduction of the material is
completed by the use
of a white stone or a finishing
diamond.
2. Fine finishing is completed with
carbide finishing burs and diamond
burs.
3. Polish with medium discs and finish
with the superfine discs.
4. Finishing strips assist in the polishing
of the interproximal surfaces.
5. Use polishing paste with a rubber
cup.
Page 64

65. • INDIRECT POSTERIOR
COMPOSITES:
• Indirect composites inlays or
onlays reduce wear and leakage
and overcome some of the
limitation of resin composites.
Several different approaches to
resin inlay construction have
been proposed.
• These include
• 1) the use of both direct and
indirect fabrication method
• 2) the application of light, heat,
pressure, or a combination of
these curing systems
• 3) the combined use of hybrid
and microfilled composites
Page 65

66. • In addition to conventional light
and heat curing, laboratory
processing may employ heat
(140 c) and pressure (0.6 MPa
for 10 min.).
• The potential advantage of these
materials is that a somewhat
higher degree of polymerization
is attained, which improves
physical properties and
resistance to wear.
• Polymerization shrinkage does
not occur in the prepared teeth,
so induced stresses and bond
failures are reduced, which
reduces the potential for
leakage.
Page 66

67. Chameleon effect
Page 67

68. Glass Ionomer
Materials
• Glass ionomer is a versatile
material with chemical properties
allowing it to be a restorative
material, liner, bonding agent, and
permanent cement.
• Glass ionomer is the generic name
of a group of materials that use
silicate glass powder and an
aqueous solution of polyacrylic
acid. This material acquired its
name from its formulation of a glass
powder and an ionomeric acid that
contains carboxyl groups. It is also
referred as polyalkenoate cement.
Page 68

69. • Micro mechanical adhesion to
enamel was really recognized
by Buonocore‟s classic paper
in 1955. He defined the
principles of the acid-etch
technique to the extent that he
is clearly regarded as the
father of the concept.
• The invention of the glass-
ionomer cement in 1969
(reported by Wilson and Kent,
1971) resulted directly from
basic studies on dental silicate
cements and studies
demonstrate that the
phosphoric acid in dental
silicate cements was replaced
by organic chelating acids.
Page 69

70. • CLASSIFICATION FOR GLASS IONOMER
CEMENT
•
• A. According to Wilson and McLean in 1988
• 1. Type I -Luting cements
• 2. Type II -Restorative cements
• -a. Restorative aesthetic
• -b. Restorative reinforced
•
• B. According to application
• 1. Type I -Luting cements
• 2. Type II -Restorative cements
• -a. Aesthetic filling materials
• -b. Reinforced materials (Fuji IX)
• 3. Type III -Lining or base cement
• 4. Type IV -Fissure Sealant
• 5. Type V -Orthodontic cement
• 6. Type VI -Core build up cement
Page 70

71. • C. According to characteristics specified by the manufacturer
•
1.Type I - Luting cement (e.g.) Fuji I, Ketac
2.Type II - Restorative material (e.g.) Ketacfil, Fuji II, Fuji IX etc
3.Type III -a. Bases & Liners-Weak with less acidic
(eg.) GC lining cement, Shofu liner
• b. Bases & Liners-Stronger but more acidic
(eg.) Ketac bond, Shofu base, GC Dentin
• c. Bases & liners-Strong even in thin layer
(eg.) Light cure (vitrabond)
4. Type IV -Admixtures (eg) Ketac Silver, Miracle Mix
Page 71

72. • D . Newer classification
•
• 1. Traditional Glass Ionomer
a. Type I - Luting cement
b. Type II - Restorative cements
c. Type III - Liners & Bases
• 2. Metal modified Glass Ionomer
a. Miracle Mix
b. Cermet Cement
3. Light Cure Glass Ionomer HEMA added to liquid
4. Hybrid Glass Ionomer / Resin modified Glass Ionomer
a. Composite resin in which fillers substituted
with glass ionomer particles
b. Pre-cured glasses blended into composites
Page 72

73. • Traditional glass ionomer Powder
• Constituent‟s % by weight
• Silica (SiO2) 35 – 50
• Alumina (Al2O3) 20 -30
• Aluminum fluoride (AlF3) 1.5 – 2.5
• Calcium fluoride (CaF2) 15 – 20
• Sodium fluoride (NaF) 3.0 – 6.0
• Aluminum phosphate (AlPO4) 4.0 – 12
• Canthanum, Strontium, Barium Traces (for radiopacity)
• Liquid
• Polyacrylic acid 45%
• Itaconic acid
• Maleic acid 5% (Decreases
viscosity)
• Tricarboxcylic acid
• Tartaric acid Traces (Increases working time
and decreases setting time)
• Water 50% (Hydrates reaction product)
Page 73

74. • INDICATIONS OF GLASS IONOMER CEMENT:
• 1. Restoration of erosion /abrasion lesions without cavity preparation
• 2. Sealing and filling of occlusal pits and fissures.
• 3.Dentin substitutes for the attachment of composite resins using the
acid etch technique.
• 4. Restoration of class 3 and 5 early carious lesions.
• 5. Lining of all types of cavities where biological seal and cariostatic
actions are required.
• 6. Minimal cavity preparations where restoration is not exposed to
high occlusal stress.
• 7. Core build-up where there is residual dentin support.
• 8. Restoration of deciduous dentin.
• 9. Provisional restorations when future veneer crowns are
contemplated.
• 10. Repair of defective margins
• 11. Sealing of root surfaces for overdentures.
• 12. Cementation of crowns and inlays, particularly in patients with a
high caries incidence
Page 74

75. CHEMISTRY OF SETTING
 Stage I Dissolution
 Stage II Precipitation of
salts, gelation and hardening
 Stage III Hydration of salts
 Stage I – Dissolution: When
the solution or the water is
mixed with the powder, the
acid goes into solution and
reacts with the outer layer of
the glass. This layer becomes
depleted in aluminum, calcium,
sodium and fluoride ions so
that only, a silica gel remains.

76.  Stage II - Precipitation of Salts,
Gelation and Hardening: During this
stage, calcium and aluminum ions bind
to polyanions via the carboxylate groups.
The initial clinical set is achieved by
cross-linking of the more readily
available calcium ions with the carboxyl
of the acid.

77.  Stage III – Hydration of salts:
Associated with the maturation phase, is
a progressive hydration of the matrix
salts, leading to sharp improvement in
physical properties.

80.  FLUORIDE RELEASE:
 One of the important
properties that glass
ionomers share with silicate is
the release of fluoride ion
throughout the life of the
restoration.
 Glass ionomer also has a
reputation for providing
resistance to further
demineralization to
surrounding and adjacent
tooth structure.

81. Indications for Using Glass Ionomers
• Primary teeth.
• Final restorations in non-stress areas.
• Intermediate restorations.
• Core material for a buildups.
• Long-term temporary restorations.
Page 81

82. Supply of Glass Ionomers
• Powder and Liquid: Manually mixed
together on a treated paper pad.
• Light-Protected Tubes: Dispensed
onto a treated paper pad.
• Paste/Paste System: Mixed for
application.
• Premeasured Capsule: Triturated for
application.
Page 82

83. • RECENT ADVANCES
• RESIN MODIFIED GLASS
IONOMERS
• Resin modified glass ionomer
restorative cements are a relatively
recent development. They were
introduced to overcome the
problems associated with the
conventional glass ionomers and at
the same time preserving the
clinical advantages of the
conventional materials.
• The approximately 5% of resin that
normally added is HEMA, along
with a small quantities of a
photoinitiator (camphoroquinone).

84.  Classification of Resin Reinforced glass ionomers
 Depends on the curing mechanism
 Dual cure: Visible light cure free-radical polymerization and glass ionomer
setting mechanism (Acid-base reaction).
 E.g. Geristore.
 Tri-cure: Visible light free radical methacrylate polymerization.
 Chemical cure of free radical methacrylate polymerization
 of composite resin.
Conventional acid base reaction.
E.g. Vitremer, Fuji II LC.
 Photocure: Visible light cure only.
 E.g. Polyacid modified composite resins, variglass, compoglass,
 Autocure: Chemical cure of the radical methacrylate polymerization only
autocure.
E.g. Prosthodont.

85. • Advantages of resin modified glass ionomer cement’s over conventional glass
ionomer cements:
• Sufficiently long working time controlled in command to a snap set by photocuring.
• Improved setting characteristics.
• Protects the acid base reaction from problems of water balance.
• Rapid development of early strength.
• Can be finished and polished immediately after set.
• Repairs can be easily carried out, as the bond between old and new material is very
strong.
• Disadvantages:
• Biocompatibility is controversial.
• Setting shrinkage is higher microleakage is more, marginal adaptation is poor.
• Low wear resistance compared to composite.
• Poor fracture toughness.
• Color that cannot compare to composite in its ability to match natural tooth coloration
• Uses:
• Used for luting stainless steel crowns, space maintainers, bands in pedo cases.
• Used as a liner and base.
• Pit and fissure sealant.

86. • COMPOMER (POLYACID MODIFIED COMPOSITE
RESINS)
• Compomers are the combination of composites (‘comp’)
and glass ionomers (‘omer’).
• Compomers contain dimethacrylate monomer and two
carboxylic groups along with ion leachable glass. There is
no water in the composition of these materials and the
glass particles are partially silanated to ensure some
bonding with the matrix. These materials set via free
radical polymerization reaction and do not bond to hard
tooth tissues.

87. • Indications
• Sealing and filling of occlusal pits and fissures
• Restoration of deciduous teeth
• Minimal cavity preparation or tunnel preparation
• Lining of all types of cavities where a biological seal and cariostatic action is
required
• Core-build up
• Replacement of carious dentine for the attachment of composite resins
• Repair of defective margins in restorations
• Restoration of Class III cavities preferably using a lingual approach
• Restoration of Class V carious lesions
• Restoration of erosion (abrasion lesion without cavity preparation)
• Sealing of root surfaces for over dentures
• Provisional restoration where future veneer crowns are contemplated
• Potential root canal sealers
• Retrograde fillings materials in endodontic emergencies
• Fine grain versions of glass ionomer cement, for luting purposes.

88. • Advantages
• Superior working characteristics to resin modified glass ionomer cement
• Ease of use
• Easily adapts to the tooth
• Good esthetics
• Good fluoride release
• Contraindications
• Class IV carious lesions
• Lesion involving large areas of labial surface where esthetics is of prime
concern
• Class II carious lesions where conventional cavities are prepared
replacements of old amalgam restorations.
• E.g. Compomer, Dyract (Dentsply), compoglass (Ivoclar), Hytac (Espe).
• Lost cusp areas
• Underneath metal/PFM crowns where light cannot penetrate

89. • GIOMER (PRE-REACTED GLASS-IONOMER)
• Giomers are a relatively new type of restorative
material. The name „giomer‟ is a hybrid of the words
„glass ionomers‟ and „composite‟. They have the
properties of both glass ionomers (fluoride
release, fluoride recharge) and resin composites
(excellent esthetics, easy polishability, and
biocompatibility).
• Indications:
• Restoration of Class I. II. III. IV, & V
• Restoration of cervical erosion and root caries
• Laminate veneers and core build-up
• Ideal for pedodontic restorations
• Other dental applications such as repair of fractured
porcelain and composite restoration

90. Ceramics
 Ceramics are compounds that involve a
combination of metallic and nonmetallic
elements, creating strength and aesthetics.
 Since the first use of porcelain to make a
complete denture by Alexis Duchateau in
1774, numerous dental porcelain
compositions have been developed.
 Porcelain compositions suitable for metal-
ceramic restorations were introduced in
1962 (Weinstein and Weinstein, 1962) and
led to the success of this technology.
 For the last ten years, the application of
high-technology processes to dental
ceramics allowed for the development of
new materials such as heat pressed,
injection-molded, slip-cast ceramics, and
glassceramics.

91.  CLASSIFICATION
 I] There are several categories of dental
ceramics :
 a) Conventional leucite-containing porcelain
 b) Leucite - enriched porcelain
 c) Ultra - low fusing porcelain that may contain :
 Leucite
 Glass – ceramic
 Specialized core ceramics like (alumina, glass
infiltrated alumina, magnesia and spinel)
 d) CAD-CAM ceramic

92.  II] Dental ceramics can be classified by :
 I) Type :
 a) Feldspathic porcelain
 b) Leucite reinforced porcelain
 c) Aluminous porcelain
 d) Alumina
 e) Glass infiltrated alumina
 f) Glass infiltrated spinel
 g) Glass ceramic

93.  II) Use :
 a) Denture teeth
 b) Metal - ceramics
 c) Veneers
 d) Inlays
 e) Crowns and anterior bridges
 III) By processing method
 a) Sintering
 b) Casting
 c) Machining
 IV) By substructure material :
 a) Cast metal
 b) Glass ceramic
 c) CAD-CAM ceramic
 d) Sintered ceramic core

94.  III] Dental porcelains are also
classified according to their firing
temperatures as follows:
 a)High fusing - 1300 C
 b)Medium fusing - 1101 - 1300 C
 c) Low fusing - 850 -1100 C
 d) Ultra low fusing - < 850 C

95. REVIEW OF NEW MATERIALS AND
PROCESSES
• Sintered porcelains
a) Leucite-reinforced feldspathic porcelain
b) Alumina-based porcelain
c) Magnesia-based core porcelain
d) Zirconia-based porcelain
• Glass-ceramics
a) Mica-based
b) Hydroxyapatite-based
c) Lithia-based
• Machinable ceramics
a) Cerec system
b) Celay system
• Slip-cast ceramics
a) Alumina-based (in-Ceram)
• Hot-pressed, injection-molded ceramics
a) Leucite-based
b) Spinel-based
Page 95

96.  Leucite-reinforced feldspathic
porcelain
 Optec HSP material (leneric/Pentron,
Inc.) is a feldspathic porcelain
containing up to 45 vol% tetragonal
leucite.
 The large amount of leucite in the
material contributes to a high thermal
contraction coefficient.

97.  Alumina-based porcelain
 Aluminous core porcelain is a typical
example of strengthening by dispersion of
a crystalline phase (McLean and
Kedge, 1987). Alumina has a high
modulus of elasticity (350 GPa) and high
fracture toughness (3.5 to 4 MPa.m05).
Its dispersion in a glassy matrix of similar
thermal expansion coefficient leads to
significant strengthening of the core.

98.  Magnesia-based core porcelain
 Magnesia core ceramic was developed as
an experimental material in 1985 (O'Brien,
1985). Its high thermal expansion
coefficient (14.5 x 10'6/°C) closely
matches that of body and incisal
porcelains designed for bonding to metal
(13.5 x 10"6/°C). The flexural strength of
unglazed magnesia core ceramic is twice
as high (131 MPa) as that of conventional
feldspathic porcelain (65 MPa).

99.  Zirconia-based porcelain
 Mirage II (Myron International, Kansas
City, KS) is a conventional feldspathic
porcelain in which tetragonal zirconia
fibers have been included. Partial
stabilization can be obtained by using
various oxides such as CaO & MgO
which allows the high-temperature
tetragonal phase to be retained at
room temperature.

100.  Glass-ceramics
 Mica-based
 The advantage of this process is that the
dental restorations can be cast by means
of the lost-wax technique, thus increasing
the homogeneity of the final product
compared with conventional sintered
feldspathic porcelains.
 Dicor (Dentsply Inc., York, PA) is a mica-
based machinable glass-ceramic.

101.  Hydroxyapatite-based
 Cerapearl (Kyocera, San Diego, CA) is a
castable glassceramic in which the
main crystalline phase is oxyapatite,
transformable into hydroxyapatite
when exposed to moisture.

102.  Lithia-based
 Glass-ceramics can be obtained from a
wide variety of compositions, leading to
a wide range of mechanical and optical
properties, depending on the nature of
the crystalline phase nucleating and
growing within the glass.

103.  Machinable ceramics
 Cerec system
 The evolution of CAD-CAM systems for the
production of machined inlays, onlays,
and crowns led to the development of a
new generation of machinable porcelains.
 There are two popular systems available
for machining all-ceramic restorations.
The glass-ceramic contains 70 vol% of the
crystalline phase.

104.  Celay system
 As with the Cerec system, the starting material
is a ceramic blank available in different shades.
One ceramic material currently available for
use with the Celay system is Vita-Celay.
 The alumina copings were further infiltrated
with glass following the conventional ln-Ceram
technique, resulting in a final marginal
accuracy within 50 um.

105.  Slip-cast ceramics
 Alumina-based (n-Ceram)
 ln-Ceram (Vident, Baldwin Park, CA) is a
slip-cast aluminous porcelain. The
alumina-based slip is applied to a gypsum
refractory die designed to shrink during
firing. This processing technique is unique
in dentistry and leads to a high-strength
material due to the presence of densely
packed alumina particles and the
reduction of porosity.

106.  Hot-pressed, injection-molded ceramics
 Leucite-based
 IPS Empress (Ivoclar USA, Amherst, NY) is a
leucite-containing porcelain. Ceramic ingots are
pressed at 1150°C (under a pressure of 0.3 to 0.4
MPa) into the refractory mold made by the lost-
wax technique.
 The ceramic ingots are available in different
shades.

107.  Spinel-based
 Alceram (Innotek Dental Corp,
Lakewood, CO) is a material for
injection-molded technology and
contains a magnesium spinel
(MgAl2O4) as the major crystalline
phase (McLean and Kedge, 1987). This
system was initially introduced as the
"shrink-free" Cerestore system.

108.  Among the currently available materials,
slip-cast ceramics exhibit the highest
values compared with all other products
(378-604 MPa). The mean flexural
strength of alumina or leucite-based
materials, whether sintered or heat-
pressed, is between 70 and 180 MPa.
Among the machinable ceramic materials,
the mica-based material (Dicor MGC) has
the highest flexural strength value (229
MPa).

109. 109
 Advantages:
- inert in body (or bioactive in body)
- high wear resistance (orthopedic &
dental applications)
- high modulus (stiffness) &
compressive strength
- fine esthetic properties for dental
applications
 Disadvantages:
- brittle (low fracture resistance, flaw
tolerance)
- low tensile strength (fibers are
exception)
- poor fatigue resistance (relates to
flaw tolerance)

117. Articles

118. • There is now occurring a movement amongst dentists to avoid doing
root canals. Ultimately root canals give people enduring medical
problems, pain and suffering.
• Ozone will immediately kill off any trace of bacteria that may remain.
There is also evidence that ozone gas will stimulate the growth of
dental tissue. (see Julian Holmes)
• Dr Allemen said that ozone will penetrate up to 2 mm into the pulp.
6th October 2009 by Arrow Durfee Posted in Disease,
Revolutionary Therapies, Oxidative Therapies, Misc

124. Forisome based biomimetic smart materials
• With the discovery in plants of the proteinaceous forisome
crystalloid (Knoblauch et al.2003), a novel, non-living, ATP-
independent biological material became available to the designer of
smart materials for advanced actuating and sensing.
• Natural systems have the capacity to sense their environment,
process this data, and respond. For example, the Venus flytrap, a
carnivorous plant,has prey-capturing behaviour and can execute
repeatable reversible mechanical actions very swiftly.

125. Microstructures of an Amelogenin Gel Matrix
• The thermo-reversible transition (clear ↔ opaque) of the amelogenin gel
matrix, which has been known for some three decades, has now been
clarified by microstructural investigations. A mixed amelogenin preparation
extracted from porcine developing enamel matrix (containing “25K,” 7.4%;
“23K,” 10.7%; “20K,” 49.5%; and smaller peptides, 32.4%) was dissolved in
dilute formic acid and reprecipitated by adjusting the pH to 6.8 with NaOH
solution
• These observations suggest that the hydrophobic interactions among
nanospheres and different orders of amelogenin assemblies are important
in determining the structural integrity of the dental enamel matrix.
Journal of Structural Biology
Volume 126, Issue 1, 1 June 1999, Pages 42-51

126. Molecular biomimetics: Utilizing nature’s
molecular ways in practical engineering
• In nature, proteins are the machinery that accomplish many
functions through their specific recognition and interactions in
biological systems from single-celled to multicellular
organisms.
• The molecular biomimetic approach opens up new avenues
for the design and utilization of multifunctional molecular
systems with wide ranging applications, from tissue
engineering, drug delivery and biosensors, to nanotechnology
and bioremediation.
Acta Biomaterialia
Volume 3, Issue 3, May 2007, Pages 289-299
2nd TMS Symposium on biological materials science

127. Biomimetic mineral coatings in dental and
orthopaedic implantology
• Biomimetic techniques are used to deposit
coatings of calcium phosphate upon medical
devices. The procedure is conducted under
near-physiological, or “biomimetic”,
conditions of temperature and pH primarily to
improve their biocompatibility and
biodegradability of the materials. The
inorganic layers generated by biomimetic
methods resemble bone mineral, and can be
degraded within a biological milieu.
Frontiers of Materials Science in China Volume 3, Number 2 / June, 2009

128. Dentistry news
vol.1 no.2

129. Dentistry news vol 2 no.1

130. Dentistry news vol 2 no.1

131. Dentistry news vol 2 no.2

132. Nothing can stop automation

133. Leonardo da Vinci
• As wrote in 16th century,
“Human ingenuity may
make various inventions,
but it will never devise
any inventions more
beautiful, nor more
simple, nor more to the
purpose than Nature does;
because in her inventions
nothing is wanting and
nothing is superfluous”.

134. 1. Operative dentistry – Gilmore 4th
edition
2. Operative dentistry – Marzouk
3. Operative dentistry –
Sturdevent’s 5th edition
4. Science of dental material –
Anusavice 11th edition
5. Fundamentals of Operative
Dentistry – Summit, Robbins,
Schwartz; 2nd edition
6. Dental material and their
selection – William J. O’briean
3rd edition
7. Introduction to Dental
Materials – Van Noort 2nd
edition
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