Tooth loss from disease has always been a feature of mankind’s existence. For centuries people have attempted to replace missing teeth using implantation. This presentation includes an introduction to implant osseointegration mechanism, various implant biomaterials, selection critria, and recent advances in the field of implant biomaterials.

1. DENTAL IMPLANT
MATERIALS
Dr. Sonali Harjani
First year postgraduate student

2. CONTENTS:
• Introduction
• Implant definition
• A peep into history
• Osseointegration
• Classification of implants
• Implant properties
• Attachment mechanisms
• Implant components
• Clinical success of implants

3. • Risk factors in implant placement
• Implant materials
-Metallic implants
-Ceramic and ceramic-coated implants
-Polymer implants
-Carbon implants
• Selecting an implant material
• Biomechanical considerations
• Recent advances
• Summary

4. INTRODUCTION:
Tooth loss from disease has always been a
feature of mankind’s existence. For centuries people
have attempted to replace missing teeth using
implantation.
But the origins of dental implants can be traced
back to as early as the Greeks, Etruscans and Egyptian
civilizations.

5. IMPLANT:
Implant is any object or material, such as an alloplastic
substance or other tissue, either partially or completely
inserted or grafted, into the body for therapeutic,
diagnostic, prosthetic, or experimental purposes.
- GPT 8

6. A PEEP INTO HISTORY…
• The use of dental implants began as far back as the early
centuries.
• The use of dental implant created from a shell was
observed in Honduras in Central America, and is dated
back to the 7th century.

7. • Albucasis de Condue (936-1013) ox bone.
The first documented placement of implants.
• Pierre Fauchard and John Hunter tooth transplantation.
towards 18th century
• The increased failure rates of transplants brought interest in
implantation of artificial roots.

8. • In 1809 Maggiolo Gold roots fixed to pivot
teeth by means of a spring.
• Harris in 1887 platinum post covered with
lead
• Bonwell in 1895 gold or iridium tubes

9. • Payne in 1898 silver capsule as
foundation for porcelain crown
• In 1905, Scholl porcelain corrugated root implant
• In 1913 Greenfield hollow basket implant made from
a meshwork of 24-gauge iridium-
platinum wires soldered with 24-
karat gold.

10. The modern implants had their origin in the discovery by the
hand of a Swedish orthopedic surgeon and research professor
touted as ‘Father of modern dental implantology’
Per-Ingvar Brånemark.
In 1952, he discovered when pure
titanium comes into direct contact
with the living bone tissue, the two
literally grow together to form a
permanent biological adhesion.
“Osseointegration”

11. Osseointegration
The process in which living bone tissue forms to within
100 Angstrom units of the implant surface without any
intervening fibrous connective tissue.

13. CLASSIFICATION OF IMPLANTS:
I. BASED ON IMPLANT DESIGN:
A. ENDOSTEAL IMPLANT
B. SUBPERIOSTEAL IMPLANT
C. TRANSOSTEAL IMPLANT
D. EPITHELIAL IMPLANT

14. II. DEPENDING ON IMPLANT MATERIAL :
A. Metals and alloys (Ti, Co-Cr-Mo alloys)
B. Non metallic (polymers, ceramics)

15. III. Based on the biologic response:
Gold
Co-Cr Alloys
Stainless steel
Zirconium
Tantalum
CP Ti
Ti Alloy (Ti-6Al-
4V)
Al2O3
ZrO2
HA
TCP
CaPO4
Fluoroapatite
Vitreous carbon
Bioglass
Polyethyene
Polyamide
PMMA
Polytetra-
fluoroethylene
Polyurethane
METALS:
CERAMICS:
POLYMERS:
BIOTOLERANT:
BIOINERT:
BIOACTIVE:

16. ENDOSTEAL IMPLANTS:
• Most commonly used implants.
• Placed into the alveolar and/or basal bone of the mandible
or maxilla and transects only one cortical plate.
• Shaped such as cylindrical cones or thin blades.
• Endosteal blade implants consist of thin plates embedded in
the bone and are used for narrow spaces such as posterior
edentulous areas.

18. ENDOSTEAL IMPLANTS:
• Another example is the ramus frame
implant, which is a horse-shoe shaped
stainless steel device.
• The most popular endosteal implant
is the root-form, designed to mimic
the shape of tooth roots for
directional load distribution as well as
for proper positioning in the bone.
• It has the most documented success
level of the endosteal implants.

19. SUBPERIOSTEAL IMPLANT:
• A custom-cast frame which is placed directly beneath the periosteum
overlying the bony cortex rests upon the bony ridge but does not
penetrate it.
• To restore partially dentate or completely edentulous jaws
• Indication: inadequate bone for endosseous implants.
• Limited use because of bone loss.

21. TRANSOSTEALIMPLANT
• Combines the subperiosteal and endosteal components.
• Penetrates both cortical plates and passes through the full thickness
of the alveolar bone.
• Use is restricted to anterior area of the mandible and provides
support for tissue borne overdentures.
• Examples include staple bone implant, mandibular staple implant,
transmandibular implant.

23. EPITHELIAL IMPLANTS:
• These are inserted into the oral mucosa.
• Simple surgical technique which requires mucosa to be used as
an attachment site for the metal inserts.
• Disadvantages include painful healing, requirements for continual
wear
• No longer used.

25. IMPLANT PROPERTIES
• These properties often include elastic moduli, tensile strength
and ductility to determine optimal clinical applications.
• An implant with comparable
elastic modulus to bone produces a more uniform
stress distribution across the interface.
• Ductility potential for permanent
deformation of abutments or fixtures in areas
of high tensile stress.

26. • Tensile, compressive and shear strength: prevents fractures and
improve functional stability.
• Yield strength, fatigue strength: prevents brittle fracture under
cyclic loading.
• Hardness and Toughness: Increase in hardness decreases the
incidence of wear of implant material and increase in toughness
prevents fracture of the implants

28. ATTACHMENT MECHANISMS
• Periodontal fibres- Most ideal form of attachment.
• Historically implant attachment through low differentiated fibrous
tissue was widely accepted as a measure of successful implant
implacement.
• Clinical studies indicate that this type of attachment eventually
leads to an acute reaction, leading to implant failure.

30. • Osseointegration described by Branemark is now the primary
attachment mechanism of commercial dental implants.
• This mode is described as direct adaptation of bone to implants
without any other interstitial tissue and is similar to tooth
ankylosis where no PDL exists: the strength of this contact
increases over time.
• Osseointegration can also be achieved through the use of
bioactive materials that stimulate the formation of bone.

31. IMPLANT COMPONENTS
• Prosthesis: can be attached via screws,
cement or precision attachment.
• Transmucosal abutment: connection
between implant fixture and prosthesis.
• Fixture: implant component that
engages the bone.
May be threaded, grooved,
perforated, plasma sprayed, or coated

32. Placement of implant done in various stages-

33. CLINICAL SUCCESS OF DENTAL IMPLANTS
In 1979, Schnitman and Schulman proposed following requirements –
• Mobility of an implant must be less than 1 mm .
• No evidence of translucency.
• Bone loss should be less than one third the height of the implants.
• There should be absence of infection, damage to structures, or
violation of body cavities.
• Success rate must be 75% or more after 5 years of functional service.

34. In 1986, Albrektsson et al included the following conditions-
• Individual, unattached implant is immobile when tested clinically.
• Radiograph does not demonstrate periapical translucency.
• Vertical bone should be less than 0.2mm following implant’s first
year of service.
• Absence of signs and symptoms such as pain, infections,
neuropathies, paresthesia, or violation of mandibular canal.
• Success rate of 85% or more at end of 5 years; and 80% at end of
10 years.

35. In 1989, Smith and Zarb modified Alberktsson’s criteria by
stating:
Patient’s and dentist’s satisfaction with the implant
prosthesis should be the primary consideration and that
aesthetic requirements should be met.

36. Suggested criteria for implant success by
Misch:
• Implant quality scale of 1, 2 or 3 with a survival rate
better than 90% in 10 years.
• Prosthesis survival rate better than 90% in 10 years.
• Implants that are supporting a prosthesis.

42. RISK FACTORS THAT CAN MINIMIZE CLINICAL
SURVIVAL
• Cigarette smoking.
• Osteopenia, Osteoporosis.
• Diabetes.
• Uncontrolled periodontal disease.
• Internal factors including bone height, bone density and
attached mucosa.
• Severe mucosal lesions.
• Previous radiotherapy to the jaws.
• Bleeding disorders.

43. IMPLANT MATERIALS:
• The most common ones are made from some form of metallic
substance.
• Some implants are not coated; others are coated with ceramic,
carbon, or a polymer.
• Implant materials are broadly: Metals and Ceramics.
• Other materials include: Polymers and carbon compounds.

44. Stainless Steel
Polymers
Polymethyl methacralate
Polytetra fluoroethylene
Carbon compounds:
Carbon
SiC
Vitreous Carbon
DENTAL
IMPLANT
MATERIALS:

45. METALLIC IMPLANTS
• Metallic implants undergo several surface modifications to
become suitable for implantation.
• Modifications are passivation, anodization, ion implantation
and texturing.
• Titanium most commonly used implant material.
• Titanium – Gold standard in implant materials.

46. TITANIUM:
• Discovered in 1789, by William Gregor.
• Atomic number – 22
• Atomic weight – 47.9
• Low specific gravity
• High heat resistance
• Melting point: 1668 degree celsius

47. • High strength
• Ti oxidizes upon contact with room temperature air and normal
tissue fluids: Oxidized surface condition minimizes bio-corrosion.
• Resistant to corrosion (due to titanium oxide): hence considered,
Self-healing. Also, Ti can repassivate in vivo.
• Pure titanium forms several oxides: TiO, Rutile (TiO2), Ilemenite
(Ti2O3)
• TiO2 most stable.

48. • Ti and Titanium alloys most commonly used namely Ti-6Al-4V and
Ti-6Al-4V extra low interstitial (ELI: low levels of O2 mixed in
interstitial sites).
• Ti-6Al-4V most commonly used.
• Modulus of elasticity of Ti-6Al-4V is closer to that of bone.
• Ensures uniform distribution of stress along the bone-implant
interface.
• ELI contains low levels of oxygen – improve the fracture toughness
of the Ti alloy.

49. The American Society for Testing and Materials(ASTM) committee
F-4 on materials for surgical implants recognizes four grades of
commercially pure Titanium and two Titanium alloys:
1. CP titanium grade I (0.18% Oxygen)
2. CP titanium grade II (0.25% Oxygen)
3. CP titanium grade III (0.35% Oxygen)
4. CP titanium grade IV (0.40% Oxygen)
1. Ti-6Al-4V alloy
2. Ti-6Al-4V ( ELI alloy)

50. ADVANTAGES:
•High degree of biocompatibility
•High strength
•High corrosion resistance.
DISADVANTAGES:
•High cost
•Difficult and dangerous to cast:
A high vacuum or ultra-
pure protective gas
atmosphere is required.

51. STAINLESS STEEL
• Surgical austenitic steel comprises of: 18% chromium and 8% nickel.
• Chromium provides corrosion resistance and nickel stabilizes the
austenitic structure.
Advantages:
• It has high strength and ductility, hence is resistant to brittle fracture.
• High Tensile strength
• Low cost and ease of fabrication

52. Disadvantages:
• Allergenic potential of Nickel.
• Susceptibility to crevice and pitting corrosion. Hence, care must be
taken to use and retain the passivated surface condition.
• There may be chances of presence of a galvanic potential with the
use of different materials such as Ti, Co, Zr, or C; which will
decrease the corrosion resistance of steel.

53. Indications:
• Fabrication of Ramus blade, Ramus frame type of
endosseous implants.
• Fabrication of mucosal insert systems.

54. COBALT-CHROMIUM MOLYBDENUM ALLOYS:
Elemental composition of this alloy consists of-
Cobalt- 63%
Chromium- 30%
Molybdenum- 5%
Carbon, manganese and nickel- traces.

55. •COBALT: provides continuous phase of the alloy
•CHROMIUM: provides corrosion resistance through the oxide
surface (Cr2O3).
•MOLYBDENUM : stabilizer; also provides strength and bulk
corrosion resistance.
•CARBON: maintains ductility
•Secondary phases based on Co, Cr, Mo, Ni and C provide strength
(4 times that of compact bone) and surface abrasion resistance.

56. • VITALLIUM was introduced by Venable in 1930’s and is part of Co-
Cr-Mo alloy family.
• TICONIUM, Ni-Cr-Mo-Be alloy, was also used as a implant material.
ADVANTAGES :
• Low cost and ease of fabrication
DISADVANTAGES :
• Poor ductility
• Vitalium showed a chronic inflammation with no epithelial
attachment and fibrous encapsulation accompanied by mobility.
• Ticonium showed less biocompatibility.

57. Indications:
• Larger implants like subperiosteal and transossteal
implants because of their castability and lower cost.
• In cases where endosseous bone is not sufficient, Co-Cr
alloy implants are used.

58. CERAMIC AND CERAMIC COATED MATERIALS:
Ceramics implants are of two types mainly:
• BIO-INERT: aluminium oxide
• BIO-ACTIVE: hydroxyapatite.
GENERAL PROPERTIES OF CERAMICS:
• High compressive strength upto 500 MPa.
• Less resistance to shear and tensile stress
• High modulus of elasticity
• Brittle

59. • Ceramic implants can withstand only relatively low tensile stresses.
• Tolerate high levels of compressive stresses.
• Al2O3 used as a gold standard for ceramic implants because of its
inertness and no evidence of immune reaction in vivo.
• ZrO2 also demonstrated high degree of inertness.
• These ceramic materials are not bio-active.
• Have high strength, stiffness, and hardness and function well as
subperiosteal or transosteal implants

60. • Use of calcium phosphates as coating materials for metallic
implants promotes bone to implant integration.
• The more HA coating the more resistant it is to clinical
dissolution.
• A min. of 50% crystalline HA is considered an optimal
concentration in coating of implants.

61. • Dissolution of the ceramic coating occurs
at a higher rate with a more amorphous
HA structure.
• Advantage of ceramic coating: they
stimulate the adaptation of bone.
• Greater bone to implant integration with
the HA coated implants.

62. • Another form of bioactive ceramics are bioglasses.
• Known to form a carbonated hydroxyapatite layer.
• Formation of layer is initiated by migration of calcium, phosphate,
silica, and sodium ions towards tissue .
• Silica gel layer is formed.

63. • Silicon depletion initiates migration of calcium and phosphate
ions .
• Calcium-phosphorous layer is formed that stimulates
osteoblasts to proliferate, stimulating the formation of bone.
• Bioglasses are very brittle, which makes them unsuitable for use
as stress bearing implant materials.

64. ADVANTAGES :
 Excellent biocompatibility
 Minimal thermal and electrical conductivity
 Color is white, cream or slightly grey: beneficial for anterior
root-form devices.
 Chemical composition is similar to constituents of normal
biological tissues.

65. DISADVANTAGES:
•Low mechanical, tensile and shear strength under fatigue
loading.
• Low ductility, inherent brittleness.
•Variations in chemical and structural characteristics
•Low attachment strengths for some coatings with substrate
interfaces.

66. POLYMERS
• Polymeric implants -First used in 1930,s.
• During 1940s methyl methacrylate was used for temporary acrylic
implants to preserve dissected space to receive a Co-Cr implant
later

67. DISADVANTAGES:
• Low mechanical strength hence susceptible to mechanical fracture
• Physical properties of polymers are greatly influenced by changes in
temperature, environment and composition.
• Their sterilization can be accomplished only by gamma irradiation
or exposure to ethylene oxide gas.
• Contamination of these polymers because of electrostatic charges
that attract dust and other impurities from the environment

68. IMZ IMPLANT:
• Intra-Mobile Cylinder implant system.
• The use of polymers for osseointegrated implants is now confined
to its components. The IMZ implants are either plasma sprayed or
HA-coated and incorporate a polyoxymethylene (POM) intra mobile
element(IME) which acts as a shock absorber.
• IME is placed between the prosthesis and the implant body to
initiate mobility, stress relief and shock absorption capability to
mimic that of the natural tooth.

69. CARBON AND ITS COMPOUNDS:
• Carbon and its compounds(C and SiC) were introduced in the
1960s for use in implantology.
• VITREOUS CARBON, which elicits a very minimal response from
the host tissues, is one of the most biocompatible material

70. ADVANTAGES:
• Carbon is inert under physiological conditions.
• Has a modulus of elasticity equivalent to that of dentin and
bone.
• Thus it deforms at the same rate as these tissues enabling
adequate stress distribution.

71. DISADVANTAGES:
• Because of its brittleness, carbon is susceptible to fracture under
tensile stress, which is usually generated as a component of
flexural stress.
• It also has a relatively low compressive strength.
• Thus a large surface area and geometry are required to resist
fracture.

72. SELECTING AN IMPLANT MATERIAL
• Important consideration is the strength of implant material and type
of bone in which implant is placed.
• For high load zone like in posterior areas, high strength material such
as CP grade IV titanium or titanium alloys are used.
• Anterior implants designated for use in narrow spaces have smaller
diameters in range of 3.25mm.
• Single implants placed in posterior areas have large diameters up to
5.0 mm

74. D1 and D2 bone → initial stability / better osseointegration
D3 and D4 → poor prognosis
D4 bone - most at risk
Jaffin and Berman (1991) – 44% failure in type IV bone

75. • Gottlander and Albrektsson examined bone to implant
contact area both at 6 weeks and 12 months for HA and CPTi
coated implants.
• They concluded that bone – implant contact at 6 weeks was
65% for HA and 59% for Ti.
• However at 12 months Ti exhibited 75% contact area versus
53% for HA

76. • Some studies showed survival rate of HA-coated implants is
initially higher than that that for titanium plasma sprayed
implants, but decreased after 4 yrs.
• Due to the adherence of microorganisms to HA surface.
• A study revealed colonisation of coccoid and rod shaped bacteria
on HA implants.
• Roughened surface of HA implants also contribute to plaque
growth once coating is exposed.

77. • Numerous osteocytes were found along periphery of HA
implants making it a better option for poor bone quality areas
such as maxilla.
• Branemark type titanium implants were evaluated in type IV
bone and a survival rate of 63% was found for mandibular
implants and 56% for maxillary implants.

78. BIOMECHANICAL CONSIDERATIONS:
• The attachment of bone to implants serves as the basis for the
biomechanics analysis performed for dental implants.
• ATTACHMENT MECHANISMS:
• Fibro osseous integration (Weiss 1986)
• Bio osseous integration ( Putter 1985)
• Osseointegration (Branemark 1969)

79. Osseointegration-
• Is defined as the close approximation of bone to an implant
material. To achieve osseointegration bone must be viable and
space between bone and implant must be less than 10 nm, and
should contain no fibrous tissue.

80. SEM of Implantation site, at bone implant interface, 28 days after
osseointegration

81. OSSEOINTEGRATION
(stable anchorage of an
implant)
OSTEOCONDUCTION
(process by which bone
grows on a surface)
OSTEOINDUCTION
(process in which there is
recruitment of immature
bone cells to form
preosteoblasts)

82. Principal factors governing osseointegration:
• SHAPE OF IMPLANT
• SHAPE OF IMPLANT THREADS
• SURFACE MODIFICATIONS

83. 1) SHAPE OF IMPLANT:
• Cylindrical/ press-fit implants cause bone resorption
• There is lack of bone steady state: micro-movements.

84. • Albrektsson in 1993, studied continuing bone saucerization of
1mm for the first year of placement of cylindrical implants,
0.5mm annually and thereafter increasing rate of resorption
upto 5 year follow-up.
• This suggested that osseointegration is poor or does not take
place in case of cylindrical implants.

85. 2) SHAPE OF IMPLANT THREADS
• These are documented for long term clinical function.
• Alteration in the design, size, and pitch of the threads influences the
long-term osseointegration.

86. THREAD PITCH:
• The more the number of
threads, the greater the
functional surface area.
• Threads improve the primary
implant stability and avoid
micro-movement of the
implants till osseointegration
is achieved.

87. 3) SURFACE MODIFICATIONS
They can be via:
• Additive methods: Titanium
plasma spraying, Hydroxyapatite
coating
• Subtractive methods: Sand
blasting, Acid etching.

88. • Titanium plasma spraying:
-Involves plasma spraying a
powder form of molten droplets at
high temperatures
- at temperatures in the
order of 15,000 degree Celsius, an
argon plasma provides a very high
velocity of 600 m/sec and partially
molten particles of titanium are
projected onto a metal or alloy
substrate.

89. • Hydroxyapatite coating:
-HA coated implant bioactive
surface structure has more rapid
osseous healing compared to smooth
surfaced implant.
-This increases the initial stability.
- Indicated in fresh extraction,
and newly grafted sites.
-Coatings are applied by plasma
spraying small sized particles of
crystalline HA ceramic powders.

90. • Sand blasting and acid etching:
-Sand blasting increases the
surface roughness, whereas acid
etching helps in cleaning.
-Sand blasting is done with
200-400 microns coarse corundum
particles and acid etching with 1% HF
acid and 30% NO2 after sand blasting
increases osseointegration.

91. RECENT ADVANCES:
• In an attempt to replace a missing tooth many materials have
been tried as an implant.
• With all the advancements and developments in science and
technology, the materials available for dental implants have
also improved.
• In the present era, due to the extensive research work and
advancements in the field of biomaterials available for dental
implants newer materials and techniques have come into
being.

92. Incorporating biologically active drugs on
the dental implant surface:
• It is studied that bisphosphonates incorporated on to titanium implants
increased bone density locally in the peri-implant region with the effect
of the anti-resorptive drug limited to the vicinity of the implant.
• Another such biologically active drug includes statins. Simvastatin-
loaded porous implant surfaces were found to promote accelerated
osteogenic differentiation of preosteoblasts, which have the potential to
improve the nature of osseointegration.
Prasad D K, Mehra D, Prasad D A. Recent advances, current concepts and future trends in oral implantology. Indian J Oral Sci
2014;5:55-62

93. Antibacterial coatings:
• Antibacterial coatings such as Gentamycin along with the
layer of HA or tetracycline treatment has been regarded as a
practical and effective chemical modality for
decontamination and detoxification of contaminated implant
surfaces.
• Further, it inhibits collagenase activity, increases cell
proliferation as well as attachment and bone healing.
Prasad D K, Mehra D, Prasad D A. Recent advances, current concepts and future trends in oral implantology. Indian J Oral Sci
2014;5:55-62

94. Titanium-zirconium alloy (Straumann Roxolid)
• Titanium zirconium alloys with 13%-17% zirconium have better
mechanical attributes, such as increased elongation and the
fatigue strength, than pure titanium.
• Growth of osteoblasts, that are essential for osseointegration is
not prevented by Titanium and Zirconium.
• Straumann developed Roxolid that is 50% stronger than pure
titanium.
Saini M, Singh Y, Arora P, Arora V, Jain K. Implant biomaterials: A comprehensive review. World J Clin Cases 2015; 3(1): 52-57

95. Titanium Porous Oxides (TiUnite ) Oral Implants:
• It was studied TPO surface possesses a considerable
osteoconductive potential promoting a high level of implant
osseointegration in type IV bone in the posterior maxilla.
• the local bone formation and osseointegration are found to be
increased.
Huang YB, Xiropaidis AV, Sorensen RG, Albandar JM, Hall J, Wikesjo UM. Bone Formation Of Titanium Porous Oxides
(TiUnite ) Oral Implants In Type IV Bone. Clinical Oral Implant Res 2005, Vol 16 Issue 1 ;105-111

96. Incorporation of Fluorides:
• By using hydrogen fluoride at low concentrations it is possible to
manipulate the titanium dioxide without changing the surface
micro texture significantly.
• Fluoride is suggested to have an action on osteoprogenitor cells
and undifferentiated osteoblasts.
• This induces the differentiation of these precursor cells into
osteoblasts and subsequently new bone formation.
• In a clinical situations, this gives a faster bone healing after
implantation and more supporting bone surrounding the implant.
Ellingsen, J. E., Thomsen, P. and Lyngstadaas, S. P. (2006), Advances in dental implant materials and tissue regeneration.
Periodontology 2000, 41: 136–156.

97. SUMMARY:
• Implant dentistry enables the restoration of nearly every clinical
situation ranging from partially to totally edentulous patients
with greater success and predictability.
• When the mechanisms that ensure implant bio acceptance and
structural stabilization are fully understood, implant failures will
become a rare occurrence.
• Modern dentistry is beginning to understand, realize, and utilize
the benefits of biotechnology in health care.
• Study of material sciences along with the biomechanical sciences
provides optimization of design and material concepts for
surgical implants; thus improving the treatment prognosis.

98. REFERENCES:
• Textbook on contemporary implant prosthesis by Carl E. Misch.
Second edition.
• Textbook on Phillip’s Science of dental materials by Kenneth J.
Anusavice. Eleventh edition.
• Textbook on Dental Implant Prosthesis by Carl E. Misch. First
edition.
• Textbook on Craig’s Restorative dental materials by Ronald L.
Sakaguchi and John M. Powers. Thirteenth edition.

99. THANK YOU!!
THANK YOU!!