Introduction History Ideal Requirements Classifications Conventional luting cements Contemporary luting cements Recent advances

1. Luting agents in fixed
prosthodontics
Dr.Ashitha Dominic

2. CONTENTS
Introduction
History
Ideal Requirements
Classifications
Conventional luting cements
Contemporary luting cements
Recent advances
2

3. INTRODUCTION

4. ‐The word luting is often used to describe the
use of a moldable substance to seal a space or
to cement 2 components together.
‐Luting is derived from a greek word LUTUM –
meaning mud.
‐ Primarily cements were used to fill the gap
between restoration and tooth structure. There
was no bonding.

5. HISTORY
1873- Silicate cement by Fletcher
1873- Zinc oxide and clove oil by Chisolm
1879- Zinc phosphate cement by Dr Pierce
1930- Calcium hydroxide paste by Hermann
1968-Polycarboxilic cement by Dennis Smith
1971-Glass ionomer cement by Wilson and Kent
5

6. Characteristics of Abutment - Prosthesis Interface
• When two relatively flat surfaces brought into
contact, space exists on microscopic scale, there
are peaks and valleys
• There are only point contacts along the peaks
• Main purpose of cement is to fill this space
completely
• If cement is not fluid enough voids can develop
around deep valleys
6

7. Procedure for cementation of prostheses
• To be effective a Type-I cement must
be fluid and be able to flow into a
continuous film of 25 um thick or less
without fragmentation
• The cement paste should coat the
entire inner surface of the crown and
extend slightly beyond the margin. It
should fill about half of interior crown
volume
• Moderate finger pressure should be used
to displace excess cement and to seat the
crown

8. Removal of excesscement
• Removal of excess cement depends on properties of
cement used
• If cement sets to a brittle state and does not adhere to
surrounding surfaces,tooth and prosthesis, it is best
removed after it sets . This applies to Zinc phosphate
and ZOE cements
• Cements which are capable of adhering chemically like
GIC, polycarboxylate and resin cement surrounding
surface is coated with petroleum jelly and remove excess
as soon as seating is completed

9. Dislodgment of prosthesis
• Recurrent caries may occur
• Disintegration of cement can result from
fracture or erosion of cement
• In oral environment , cement layer near the
margin can dissolve and erode leaving a
space. This space can be susceptible to
plaque accumulation and recurrent caries
9

10. Ideal requirements of luting cements
‐ Adhesion to restorative material
‐ Adequate strength to resist functional forces
‐ Lack of solubility in oral fluids
‐ Low film thickness
‐ Biocompatibility with oral tissues
‐ Possession of anticariogenic properties
‐ Radioopaque
‐ Relative ease of manipulation
‐ Esthetic/colour stability
10

11. CLASSIFICATION
11

12. BASED ON INGREDIENTS AND APPLICATION
Water based cements
o Glass & Resin modified glass ionomer
o Zinc Polyacrylate
o Zinc Phosphate
Resin based cements
o Composite & adhesive resin
o Compomers
Oil based cements
o Zinc Oxide Eugenol
o Non Eugenol -Zinc Oxide

13. Based on the bonding mechanism(Williams O'Brien. 2002 &
Richard van Noort)
Phosphate based :
‐ Zinc phosphate cement
‐ Modified zinc phosphate cement
Fluoridated cement
Copper cement
Silicophosphate cement

14. Phenolate based :
‐ Zinc oxide eugenol cement
‐ Reinforced zinc oxide eugenol
‐ EBA and other chelate cements
‐ Calcium hydroxide chelate cement
Polycarboxylate based:
‐ Zinc polycarboxylate cement
‐ Glass ionomer cement
Methacrylate based:
‐ Acrylic cements
‐ BIS-GMA type cements
14

15. based on setting reaction( Skinners)
Acid Base Reaction
Zinc phosphate
Zinc polycarboxylate
Zinc oxide eugenol
Glass ionomer cement
Light / Chemical activities
Polymerization and acid base reaction
Resin modified glass ionomer cement
Compomer
Resin cement

16. Zinc phosphate cement
ADA Specification : 8
Oldest of the luting cement -1878
Supplied as a powder and liquid
16

17. POWDER
Zinc oxide - 90%
Magnesium oxide – 9-10%
Silicon dioxide – 1.4%
Bismuth trioxide - .1%
Barium oxide – traces
sintered at temperatures between 1000deg Celsius and
1400 deg Celsius -> cake -> fine powder
17

18. LIQUID
Phosphoric acid
Water – 36%
Aluminium Phosphate
Zinc Phosphate (some times)
‐ Water controls the ionization reaction of acid - in
turn influence the rate of acid base reaction
‐ Acid content of the liquid - 33% approximately.

19. CLASSIFICATION(Anusavice 9th edition)
Type I -Fine grained for luting
-Film thickness should be less than 25 um
Type II - Medium grained
- Film thickness 40um
- High strength thermal insulating base
19

20. WORKING AND SETTING TIME
‐ Mixing time – 1.5-2 min
‐ Setting time – 2.5-8 min
‐ The following procedures can extend the setting
time
Reducing p/l ratio
Mixing in increments
Prolonging the spatulation of last increment
Cooling the glass slab
20

21. PHYSICAL PROPERTIES
‐ Compressive strength :104MPa
‐ Tensile strength:5.5MPa
‐ Low water solubility 0.04wt%- More soluble in
dilute organic acids
‐ Modulus of elasticity:13.7GPa - Quiet stiff &
resistant to elastic deformation
21

22. BIOLOGICAL PROPERTIES
‐ Acidity of cement is quite high during the time of
application - presence of phosphoric acid 2 min
after the start of mixing , Ph is 2 increases rapidly
reaches about 5.5 in 24 hrs
‐ Pulpal damage can occur during first few hours
High heat production during setting of the cement
can also cause pulpal injury.
22

23. MANIPULATION
‐ Dispense the cement P/L :1.4 gm /
0.5 ml.
‐ Divide the powder in one corner of
the glass slab into increments.
‐ Dispense the correct amount of
liquid, to area of the slab away
from the powder.
‐ Add the powder to liquid in
portions at 15 sec intervals for a
mixing time 60-120 sec
23

24. ‐ Mix it over a large area of the slab with a metal
spatula.
‐ Test the consistency of the cement before adding
the last portion of powder.
24

25. FrozenSlab Technique
‐ Practical way to increase the working time and
reduce the setting time of zinc phosphate cement.
‐ 50% increased powder/liquid ratio.
‐ Effective when multiple castings are to be
cemented.
‐ Excess of cement is easy to clean up . But decrease
in compressive strength.
‐ Working time – 4-11 mins
‐ Setting time - 20-40% shortened

26. SETTING REACTION
Powder & liquid mixed
Phosphoric acid attacks the surface of the particle
Release of zinc ions & reaction of Al with phosphoric acid
Al & Zn ions react with phosphoric acid
Zinc alumino phosphate gel
Surrounds with unreacted particle

27. Advantages
‐ • High compressive
strength
‐ • Good thermal and
electrical insulator
‐ • Low solubility
Disadvantages
‐ • Brittle
‐ • Low tensile strength
‐ • Cannot be used to
lute full ceramic
‐ • No chemical adhesion
‐ • Pulp irritant
27

28. ZINC SILICOPHOSPHATE CEMENT
‐ They are also called as Zinc silicate, Silicate zinc
cement.
‐ Zinc silicophosphate cement is a hybrid resulting
from the combination of zinc phosphate cement
and silicate powders.
28

29. According to ADA no –28 (1969) there are three
types
‐ Type I – as a cementing media
‐ Type II – temporary posterior filling material
‐ Type III – dual purpose cementing media and
temporary posterior filling material.
29

30. Composition
Powder
- Silicate glass
- zinc oxide,
- 13-25% fluoride
Liquid
- 50% phosphoric acid
- 45% water
- 4-9% zinc
- 2% Al.
30

31. Advantages
‐ Better strength and toughness than zinc phosphate
cements
‐ Shows considerable fluoride release hence anticariogenic
‐ Translucent
‐ Under clinical conditions lower solubility and better
bonding
‐ Best suited to cement of ortho bars and restoration on
non-vital teeth.
Disadvantages
‐ Less satisfactory mixing
‐ Higher film thickness
‐ Greater pulpal irritation 31

32. ZINC POLYCARBOXYLATE CEMENT
‐ In the quest for an adhesive cement that can bond
strongly to the tooth structure, Zinc
polycarboxylate cement was the first cement
system that developed an adhesive bond to tooth
structure in 1960.
32

33. COMPOSITION
POWDER
‐ • Zinc oxide – 72%
‐ • Magnesium oxide – 7%
‐ • Other oxides like bismuth and aluminium
‐ • Stannous fluoride
33

34. LIQUID
‐ • Liqueous solution of polyacrylic acid (32-48%) Or
• Copolymer of acrylic acid with other unsaturated
carboxylic acids (itaconic , maleic , tricarballylic
acids)
‐ • Itaconic & tartaric – prevent gelling
‐ • Viscosity of liquid can be prevented by adjusting
ph by adding sodium hydroxide
34

35. MANIPULATION
• A cooled glass slab / powder
• 1.5 parts of powder to 1 part of liquid by
weight
• Liquid not dispensed , before the start
• Loss of water, increases viscosity
• Powder is rapidly incorporated into the
liquid in large quantities
• Mixing time is with in 30 – 60 sec ,with
half to all of powder incorporated at once to
provide the maximum length of working time
. 35

36. MECHANICAL PROPERTIES
‐ Compressive strength : 55-67 Mpa
‐ Tensile strength : 2.4-4.4 Gpa
‐ Modules of elasticity is lower then zinc phosphate
cement 5.1GPa
‐ More soluble than zinc phosphate cement 0.06%
‐ More soluble in organic acids.
‐ Not as brittle as zinc phosphate cement
36

37. BIOLOGICAL PROPERTIES
‐ • Pulpal response termed as mild
‐ • Ph of liquid is 1- 1.7
‐ • Freshly mixed cement – 3-4
‐ • After 24 hrs – 5 -6
37

38. CHEMICAL REACTION
When acid comes in contact with powder , acid reacts
and releases zinc, magnesium, and tin ions
They bond to the polymer chain , through the
carboxyl groups
These ions also react with carboxylic groups of
adjacent poly acid chains
Cross Linked salts are formed

39. Applications
‐ • Primarily for luting permanent restorations
‐ • As bases and liners
‐ • Cementation in orthodontic bands
‐ • Pedo stainless steel crowns
39

40. Advantages
‐ Biocompatibility with the pulp is excellent.
‐ Postoperative sensitivity is negligible when used as
a luting agent
‐ Adhesion to tooth and alloy
‐ Easy manipulation.
Disadvantages
‐ Greater viscoelasticity
‐ Shorter working time
‐ Low compressive strength
‐ More critical manipulation.
40

41. ZINC OXIDE EUGENOL
‐ • These cements have been extensively
used in dentistry since 1890’ s
‐ • They are least irritant of all dental
cements
‐ • Have an obtundant or sedative effect
‐ • Compatible with the hard and soft
tissues of the mouth
41

42. CLASSIFICATION
‐ • Type 1 ZOE – for temporary cementation
‐ • Type 2 ZOE – permanent cementation
‐ • Type 3 ZOE – temporary filling material ,
thermal insulation
‐ • Type 4 ZOE – Cavity liners
42

43. COMPOSITION
POWDER
• Zinc oxide – 69%
• White rosin –
29.3% • Zinc
stearate – 1%
• Zinc acetate –
0.7%
• Magnesium oxide
LIQUID
– Eugenol – 85% - reacts
with zinc oxide
– Olive oil – 15% -
plasticizer
43

44. SETTING REACTION
‐ • First , hydrolysis of zinc oxide to its hydroxide
‐ • Water is essential for reaction to proceed
‐ • It is a acid base reaction
‐ • Zinc hydroxide combines with eugenol to form a
chelate
ZnO + H2O → Zn(OH)2
‐ • ZINC EUGENOLATE
‐ • Forms an amorphous gel, which later tends to
crystallize.
Zn(OH)2 + 2HE → ZnE2 + 2H2O
44

45. MANIPULATION
‐ • p/l ratio 4:1 to 6:1 by
wt
‐ • the bulk - incorporated
into the liquid -
spatulated thoroughly in
a circular motion - a stiff
bladed spatula
‐ • Small increments -
until the mix is complete
45

46. ‐ • Setting time - 4-10 mins
‐ • Complete setting reaction between zinc oxide and
eugenol takes about 12 hrs
Factors affecting setting time:
• Particle size – smaller particle size, set faster
• Accelerators – alcohol , glacial acetic acid , and
small amounts of water
• Retarders – glycol, glycerine
• Temperature – high temperature , accelerate
setting
• Powder/ liquid ratio – higher the ratio, faster the
setting

47. Physical properties
‐ • Relatively week cements
‐ • Compressive strength : Ranges from 3-4mpa to
50- 55mpa
‐ • Tensile strength : 0.32 to 5.8mpa
‐ • Modules of elasticity : 0.22 – 5.4 mpa
‐ • thermal insulator
‐ • Solubility of the set cement is high - disintegrate
in oral fluids - Solubility is reduced by increasing
p/l ratio
47

48. Biological properties
‐ • Least irritating of all dental cements
‐ • Ph is 6.6 – 8
‐ • Pulp response is termed as mild
‐ • They inhibit the growth of bacteria , have an
soothing effect on pulp , in deep cavities, hence
reduces pain
48

49. Modifications of ZOE
‐ Resin Reinforced Zinc Oxide Eugenol Cement
‐ EBA and other Chelate Cements
49

50. COMPOSITION
POWDER
‐ Zinc powder – 80.0%
‐ Poly methyl-methacrylate – 20.0%(bond to other
components)
‐ Zinc stearate - traces (accelerator)
‐ Zinc acetate
‐ Thymol & hydroxyquinoline – traces (antimicrobial agent)
LIQUID
‐ Eugenol – 85%
‐ Olive oil – 15% -(as plasticizer ,masks irritating effect of
eugenol).

51. EBA AND OTHER CHELATE CEMENTS
COMPOSITION
Powder
‐ ZnO
‐ Aluminium oxide/other mineral fillers – 20-30%
‐ Polymeric reinforcing agent (poly methyl
methacrylate)
‐ Barium sulphate - radiopacity
Liquid
‐ O- ethoxy benzoic acid 50- 60%
‐ Eugenol – Remaining part
51

52. NON-EUGENOL CEMENT (CAVIT)
A premixed non eugenol paste used for temporary
restorations & cavity bases.
Contains
‐ Zinc oxide
‐ Zinc sulphate
‐ Calcium sulphate
‐ Glycol acetate
‐ Poly vinyl acetate
‐ Triethanolamine
‐ Red pigments

53. ‐ Setting reaction initiated by saliva & water.
‐ Better sealing into cavity walls
‐ Minimum thickness of at least 3 to 3.5 mm
required.
‐ It is not satisfactory material for cementation.
‐ When inserted into dry cavity it creates negative
pressure, causing aspiration of odontoblast leading to
pain.
‐ PH same as ZOE.
53

54. “
GOOD MORNING
54

55. GLASS IONOMER CEMENT
‐ Water based cement
‐ ADA spec no: 96
‐ Glass ionomer is the generic name of a group of
materials that use silicate glass powder and an
aqueous solution of polyacrylic acid.
55

56. Type I
‐ Luting applications
‐ Powder liquid ratio is generally 1.5 : 1
‐ Grain size 15 µm or less
‐ Radiopaque for easy detection of excess
Type II
‐ Restorative material
‐ Powder liquid ratio 3:1
‐ Must be protected for 24 hours for best results

57. Type III
‐ Liner and base.
‐ Powder liquid ratio varies according to use
‐ Lining requires 1.5:1 powder liquid ratio for easy
manipulation
‐ Base requires 3:1 or greater for strength
‐ Light activated varieties available
Type IV
‐ Fissures & sealants

58. Type V – luting for orthodontic purpose
Type VI – core buildup material
Type VII – high fluoride releasing
Type VIII – atraumatic restorative material
Type IX – pediatric gic
58

59. COMPOSITION

60. LIQUID
• Polyacrylic acid - 45 %
• Water - 50 %
• Modifiers
Itaconic acid -0.5 %
maleic acid
tricarboxylic acid ↓ viscosity , inhibits
gelation.
• Tartaric acid.
60

61. • Fluoride is an essential constituent which
‐ - Lowers fusion temp., acts as flux
‐ - improves working characteristics & strength
‐ - improves translucency
‐ - improves therapeutic value of the cement by
releasing fluoride over a prolonged period
• Al3PO4
‐ -Improves translucency. Apparently adds body to
the cement paste
61

62. Polyacrylic acid
‐ is the most important acid contributing to
formation of the cement matrix.
Water
‐ It is reaction medium.
‐ It serves to hydrate the siliceous hydrogel and the
metal salts formed.
Itaconic acid
‐ promotes reactivity between the glass and the
liquid.
‐ It also prevents gelation of the liquid which can
result from hydrogen bonding between two
polyacrylic acid chains 62

63. Maleic acid
‐ A stronger acid than polyacrylic acid
‐ Causes the cement to harden and lose its moisture
sensitivity faster.
Tartaric acid
‐ It is a hardener that controls the PH of the set
cement during setting process, which in turn
controls the rate of dissolution of the glass.
63

64. Working time & setting time
‐ • It sets rapidly in the mouth that is within 3-5
min and hardens to form a body having
translucency that matches enamel
‐ • Setting time for type I –GIC – 5 -7 min
‐ • Setting time for type II–GIC --10 min
‐ • Film thickness should not exceed 20μm for luting
agents
64

65. Setting reaction
Decomposition – decomposition of glass powder by
acid resulting in release of ions
Migration – ions migrate into aqueous medium
Gelation – caused by aluminium & calcium ions
Post set hardening & slow maturation – hardening &
precipitation happens for 24 hrs accompanied by
slight expansion under conditions of high humidity
and development of translucency
65

66. Biocompatibility
‐ • Resistance to plaque because presence of F
‐ • Pulp response to GIC is favorable
‐ • Freshly mixed - acidic pH 0.9 – 1.6 -- mild
inflammation resolve 10 -20 days
‐ used to protect mech / traumatic exposure of
healthy pulp
‐ • Glass ionomer cement showed greater
inflammatory response than ZOE but less than Zn
phosphate cement, other cements but it resolved in
30 days
66

67. Thermal Properties
‐ •The thermal diffusivity value of GIC is close to
that for dentin.
‐ • The material has an adequate thermal insulating
effect on the pulp and helps to protect it from
thermal trauma
67

68. Solubility & disintegration
• lower than ----Zn phosphate Zn
polycarboxylate
• In water --- less than Silicate cement
• Resin-modified GIC is less resistant to solubility
68

69. ESTHETICS
‐ • Glass ionomer cement has got a degree of
translucency because of its glass filler
‐ • Unlike composite resins, glass ionomer cement will
not be affected by oral fluids
69

70. DURABILITY
Affected by the factors
• Inadequate preparation of the cement
• Inadequate protection of restoration
• Variable conditions of mouth
‐ Failure rate is more a measure of clinician’s skill
than inherent quality of the material
70

71. • Some other properties
• Low exothermic reaction
• Adheres chemically to the tooth structure
• Less shrinkage than polymerizing resins
• F release discourages microbial infiltration
• Poor abrasion resistance
• Average esthetic
71

72. RESIN MODIFIED GLASS IONOMER CEMENTS
RMGIC can be defined as a hybrid cement that sets
via an acid base reaction and partly via a photo-
chemical polymerization reaction.
72

73. Setting reaction
‐ • 2 distinct setting reactions occur
‐ • Acid base neutralization
‐ • Free radicle cure.
‐ This can occur purely via light cure or by a
combination of LC and chemical cure.
‐ • Thus a cement can be termed - dual cure if cross
linking is via acid base + LC or - tri cure if its via
acid base + Light cure + chemical cure
73

74. COMPOSITION
Powder
‐ • Ion leachable glass
and initiators for
light /chemical /
both types of curing
Liquid
‐ • Water
‐ • Polyacrylic acid
modified with MA &
HEMA (15-
25%)monomers.
‐ • water
‐ tartaric acid

75. ADVANTAGES
‐ • Long Working time and Snap setting
‐ • Early water sensitivity is reduced
‐ • No etching is needed either to tooth for adhesion
or for the material if composite lamination is to be
done.
‐ • Bonding to composite is higher
‐ • Finishing can be done immediately
‐ • F release
‐ • Diametrical tensile strength is higher
75

76. DISADVANTAGES
‐ • Increased shrinkage with concurrent
microleakage
‐ • Low wear resistance as compared to
composites
‐ • Its controversial biocompatibility
76

77. POLYACID MODIFIED RESIN COMPOSITE /COMPOMER
Fluoride releasing capability of gic
+
Durability of composite
COMPOMER
77

78. ‐ Compomer can be defined as a material that contains
both the essential components of GIC but at levels
insufficient to promote the acid –base curing reaction in
the dark
COMPOSITION
‐ • one – paste system containing ion leachable glass &
polymerizable acidic monomers with functional groups of
polyacrylic acid & methacrylates in 1 molecule.
‐ • NaF and some other fillers are also present for
additional F release.
‐ • no water
‐ • Glass particles are partially silanated to ensure bonding.
78

79. SETTING REACTION
Setting reaction occurs in 2 stages
‐ • Stage 1: In contrast to RMGIC, a typical
composite resin network around filler particles
forms on light activation
‐ • Stage II : occurs over 2-3 months where by water
from the saliva gets absorbed and initiates a slow
acid base reaction with formation of hydrogels
within the resin and low level fluoride release.
79

80. Manipulation
‐ Dry the tooth to be cemented but do not desiccate.
The powder liquid ratio is 2 scoops to 2 drops.
Tumble the powder before dispensing. Mix the
powder and the liquid rapidly for 30 seconds. Place
the mixed cement in the crown only and then seat
the crown.
‐ A gel state is reached after 1 minute, at which
time the excess cement is removed with floss and a
scaler. Light cure the exposed margins to stabilize
the restoration. Setting occurs 3 minutes after
start of mix. Once set, compomer cement is very
hard.

81. INDICATIONS
‐ • P& F sealant
‐ • Restoration of primary teeth, class III and V
lesions along with cervical abrasions and erosions
and intermediate restorations
‐ • Bases for composites, liners
‐ • Small core build ups
‐ • Filling of pot holes & undercuts in old crown
preparations
‐ • Root surface sealing
81

82. ADVANTAGES
‐ • Superior working characteristics to RMGIC
‐ • Ease of use
‐ • Easily adapts to the tooth
‐ • Good esthetics
82

83. Condensable / Self hardening GIC
‐ • These are basically, purely chemically activated
RMGIC with no light activation at all.
‐ • Developed mainly for luting purposes, they
contain monomers and chemical initiatiors such a
the benzoyl peroxide and t- amines to allow self
polymerization.
‐ • It is used mainly in paediatric dentistry for
cementation of stainless steel crowns,space
maintainers, bands and brackets
83

84. Advantages over conventional GIC’s ( A Castro
& R F Feigal,2001)
‐ • Packable + Condensable
‐ • Easy placement
‐ • Non sticky
‐ • Rapid finishing can be carried out
‐ • Improved wear resistance
‐ • Solubility in oral fluids is very low
84

85. CALCIUM ALUMINATE GIC
‐ • A hybrid product with a composition between
that of calcium aluminate and GIC, designed for
luting fixed prostheses.
‐ • The calcium aluminate component is made by
sintering a mixture of Al2O3 and CaO
(approximately 1 : 1 ratio) to create monocalcium
aluminate.
85

86. COMPOSITION
POWDER
‐ • calcium aluminate
• polyacrylic acid
‐ • tartaric acid
‐ • Strontium
fluoroaluminoglass
‐ • strontium fluoride
LIQUID
‐ • 99.6% water
‐ • 0.4% additives for
controlling setting.
86

87. ‐ The calcium aluminate contributes to a basic pH
during curing, reduction in microleakage, excellent
biocompatibility, and long-term stability and
strength.
87

88. RESIN CEMENTS
• Composite resins - compound of two or more
distinctly different materials with properties that
are superior to individual constituents
• Cements based on resin composites
‐ – Class I – self cured materials
‐ – Class 2 – Light cured
‐ – Class 3 - Dual cure

89. • Composition and chemistry
Powder /liquid or two paste form.
Resin matrix / binder– Bis GMA / urethane
dimethacrylate, triethylene glycol dimethacrylate
Fillers – quartz ,colloidal silica /metal oxides
Coupling agents – organosilanes
Also contains – Hydroquinone: prevents
premature polymerisation,
Opacifiers: Ti dioxide ,Al oxide
Colour pigments to match the tooth colour
89

90. ADVANTAGES:
‐ Low solubility
‐ Good retention
Strength
‐ Good aesthetics
‐ Useful in ceramic
veneers and inlay
DISADVANTAGES:
‐ More film thickness
‐ Microleakage due to
polymerisation
shrinkage
‐ Pulp irritation
‐ Cost
90

91. ADHESIVE RESIN CEMENTS
‐ These are new generations of adhesive bonding agents
which are been used extensively in dentistry now.
‐ • Since composite resins are very viscous they do not flow
well into the dentinal tubules of etched surface
‐ • Bonding is achieved with organophosphonates HEMA
(hydroxyl ethyl methacrylate) or 4-META (4-
methacryloxy ethyl trimellitic anhydride)
‐ • The phosphate end of the phosphonate reacts with
calcium of the tooth or with a metal oxide.
91

92. Bonding of esthetic restorations
‐ – Dual cure resin – ideal for ceramic restorations
,composite inlays
‐ – Light cure cements -bonding thin ceramic
veneers , resin bonded prosthesis
‐ – Light cure more color stable
92

93. • Composition
‐ – Microfilled /hybrid composite –> BIS-GMA or
urethane dimethacrylate resins
‐ – Silica or glass fillers – 20 to 70 %
• Dual cured cement – base- catalyst forms
• Light cured composite - photointiated
93

94. Manipulation
• Bonding is achieved by performing the following
steps:
1. Etching fitting surface of ceramic with
hydrofluoric acid
2. Apply silane coupling agent to ceramic
3. Etch enamel with phosphoric acid
4. Applying a resin bonding agent to etched
enamel and silane
5. Seating the restoration with a composite resin
luting agent
94

95. Advantage
‐ Adhesive to tooth
structure
‐ Very high retention
Low solubility in oral
fluids
‐ Aesthetic
‐ High Strength
Disadvantage
‐ Pulp irritation
‐ Post insertion
sensitivity
‐ Cost
‐ Technique sensitive
95

96. Resin-metal bonding
‐ • Bondable surface roughened by electrochemical
etching or by grit blasting with 30 to 50 μm
alumina particles at an air pressure of 0.4 to 0.7
MPa.
‐ • Some bonding systems include a metal primer
containing an adhesion promoter.
‐ • Oxide formation on base metal surfaces
contributes to bond strength when resin cement
containing 4-METAbased resin is used.
96

97. 97

98. 98

99. CONCLUSION
‐ Luting agents possess varied, complex chemistries
that affect their physical properties, longevity and
suitability in clinical situations. It appears a single
adhesive will not suffice in modern day practice. To
date, no adhesive can completely compensate for
the shortcomings of the preparation retention and
resistance forms or ill fitting, low strength
restorations. Prosthdontics must be aware of the
virtues and shortcomings of each cement type and
select them appropriately.

100. References
‐ • Phillips’ science of dental materials, 11th ed,
Anusavice
‐ • Philips science of dental materials 12th
edition
‐ • Contemporary fixed prosthodontics , 4 th
edition Rosensteil
100