1. GLASS IONOMER CEMENTS
dr shabeel pn

4. INTRODUCTION Salt formed by reaction between poly alkenoic acid and
GIC is an adhesive tooth coloured restorative material used for eroded areas and now it has been used for other areas also .
Salt formed by reaction between poly alkenoic acid and
Calcium aluminoflurosilicate glass .

5. HISTORY developed by Wilson & Kent in 1972 .
Yogi etal – GI cement is used as a sealent for
partially erupted permanent molars .
Groll etal – 1993 – Recommended light curable glass
polyalkeonate for amalgam replacement .
Althadaing etal – light cured glass ionomer
for repairing furcated
areas on the pulpal floor .
Thevadans etal – 1996 – Mixing of 4 % NaF with GIC. .

6. Historical evolution of GIC

7. ASPA (aluminosilicatepolyacrylic acid )
Also named as……
polyalkeonates .
ASPA (aluminosilicatepolyacrylic acid )
developed by Wilson etal .

8. ADVANTAGES Tooth coloured material .
It will adhere directly to both enamel and dentine
through ion exchange mechanism .
Biologically active as it is capable of releasing
fluorides , calcium and phosphate .

9. CLASSIFCATION

10. CLASSIFICATION TYPE I - Luting TYPE II – Resoration .
TYPE III – Liners and bases .
TYPE IV - Pit and fissure sealants .
TYPE V – Orthodontic cements .
TYPE VI – Core built up.

11. CLASSIFICATION…… TYPE I - Luting TYPE II - Restoration
TYPE III Liners & Bases
TYPE IV Resin modified
TYPE V Metal modified
TYPE VI Ceromers
TYPE VII Compomers
TYPE VIII Geriatric
TYPE IX Pediatric

12. CLASSIFICATION BY G J MOUNT
Based on the - water powder ratio.
physical properties .
clinical application .
TYPE I – Luting agents .
TYPE II i – Esthetic restoration .
TYPE II ii – Non esthetic restoration .
TYPE III - Liners and bases .

13. CLASSIFICATION NO:3 TYPE I Conventional TYPE II Restorative
Class 1 – esthetic restorative cements .
Class 2 – reinforced restorative cements or metal
modified glass ionomer .
TYPE III
Light cured lining glass ionomer cement
( liners and bases ) .

14. TYPE I –CONVENTIONAL GI.
Mostly used in cementing , luting , liners and bases .
Powder particle size – 15 micron .
Thickness of cement film – 2 micron .
Thin pulpal dentin is required to be protected
with hard Setting Ca ( OH )2 .

15. TYPE II RESTORATIVE GIC
Class I esthetic restorative cement
Mostly used for anterior restorations
Class II reinforced restoration cements

16. A ) Amalgam alloys mixed with cements.
Class I reinforced restoration cement ( metal modified , posterior GI)
Mostly used for posterior restorations .
A ) Amalgam alloys mixed with cements.
B ) Cermet ( ceramic metal mixture )
Glass powder is fused and sintered with Ag particles .

17. PROPERTIES Resistance to wear as they are stronger and tougher .
Poor esthetics due metallic color
Less pulpal irritation .
Posses anticariogenic properties

18. TYPE 3 a – Light cured lining glass ionomer cements
HEMA ( hydroxy ethyl methacrylate ) added to light component .
Reduce shrinkage .
To increase strength , powder mixed with alumino – silicate glass.

19. Light cured GIC

20. TYPE 3 b – Light cured glass ionomer cement
COMPOSITION
POWDER - ion leachable glass .
LIQUID - Polyacrylic acid or
Polyacrylic acid with HEMA .
SETTING REACTION
Initial set – polymerization of methacrylate gp
Final set – slow acid – base reaction

21. PROPERTIES Reduced translucency . Increased tensile strength
Stronger adhesion to teeth surface .
Decreased marginal adaption and increased marginal leakage due to polymerization shrinkage .

22. TYPE 4 Hybrid resin modified G I
Used as restorative filling material.
HEMA added to liquid component - bonding.
Have higher resistance to wear & tear.
Used in class 1,2,5 filling with conservative cavity preparation.
Avoid cavities in deciduous teeth.

23. Light cured GIC

24. AVAILABLE AS… Powder – liquid system . Pre – proportionate capsule .
Light cure system .
Dual cure system (chemical +light) .

25. Luting ,restorative & root canal cements

26. Cement dispensing system

27. COMPOSITION

28. acid soluble calcium fluoro aluminosilicate glass
POWDER
acid soluble calcium fluoro aluminosilicate glass
SiO %
Al2O %
AlF %
CaF %
NaF %
AlPO %

29. Fluoride component - ceramic flux .
Lanthanum , strontium,barium , ZnO radiopacity .
Fine colloidal Ag and amalgam -
enhance the properties.

30. 40 -50% acidic solution…… Poly acrylic acid . Tartaric acid . Water.
LIQUID
40 -50% acidic solution……
Poly acrylic acid .
Tartaric acid .
Water.

31. Poly acrylic acid – very viscous
Tendancy to gelation .
Poly acrylic acid co-polymerized with itaconic acid maleic acid .
Increases the reactivity of liquid .
Decreases the viscosity .
Decreases the tendency to gelation .

32. TARTARIC ACID WATER Improve the handling character .
Decreases the viscosity .
Increases the working time .
Decreases the setting time .
WATER
Most important constituents .
Too much of water- weak cement .
Too little water – dehydration .

33. SETTING REACTION
The liquid acid may be freeze dried and combined with powder [ to have better shelf life and lower viscosity which are important characteristics for luting agents .
Mix can be done on a disposable moisture resistant paper pad or a glass slab .
A plastic spatula is preferred to a metal one to minimize contamination of the mix from eroded metal .
Large increment of powder are rapidly incorporated into the liquid and mixing should be completed within 40 sec Working time – short , not more than 3 min from start of mixing .

34. SETTING REACTION

37. Powder and liquid mixed together Acid attacks the glass particles
Powder and liquid mixed together Acid attacks the glass particles Na,Ca,Al ,F ions are leached into the aquous solution Ca poly salts in the beginning and later Al – poly salts Two salts cross links to form polyanionic chain.

38. STRUCTURE OF SET CEMENT
Agglomerates of un reacted powder particles surrounded by silica gel and embedded in an amorphous matrix of hydrated Ca-Al polysalts .
Fresh cement once hardened is prone to cracking and crazing due to loosely bound water which is readily removed from mix .
Setting time – Type – 5 min
Type min

39. STEPS IN GI RESTORATION

40. Conditioning of tooth preparation Proper manipulation
Cavity preparation
Conditioning of tooth preparation
Proper manipulation
Protection of cement from setting
Finishing

41. CAVITY PREPARATION
Proper adhesion → resistance → retention is achieved by proper cavity preparation .
Eroded rough surfaces can be restored after acid etching alone without proper preparation.

42. CONDITIONING OF TOOTH PREPARATION
Chemical adhesion of cement with tooth surface .
Surface should be free of saliva, blood and completely dry .
Smear layer on the cavity should be removed .
This is done by
Pumice wash
10 % polyacrylic acid
37 % H3PO4
Time 10 to 20 sec

43. Surface of dentin after application of……….
37% ortho phosphoric acid
10% poly acrylic acid

45. PROPER MANIPULATION P/L ratio - type I 3:2 type II 3:1 Hand mixing
Capsule mixing

46. Hand mixing Divide the dispersed powder into two equal parts .
Powder is incoperated rapidly into liquid .
Mixing should be done in a folding manner in order to preserve the gel structure .
10 sec after adding first increment , 2nd increment is added to liquid .
The final mix should be with in 25 to 30 sec .

49. CAPSULE MIXING Amalgamator is used for mixing
Powder and liquid contained within capsule by
removing the seal separating the liquid and powder .
After mixing is completed by vibration nozzle of the capsule is pierced and the cement is dispersed directly on the prepared cavity .
Advantage
Control over p/l ration
Convenience

50. Mechanical mixing

51. PROTECTION OF CEMENT DURING SETTING
Matrix placement
Matrix removal

52. MATRIX PLACEMENT ADVANTAGES
Pre contoured matrix is placed over the cement in the cavity for a period of 5 – 8 mts
ADVANTAGES
- Provide best possible surface integrity
- provide maximum contour
- prevent loose or gain of water from cement before initial setting is completed .

53. MATRIX REMOVAL
– After initial setting the matrix is removed.
Excess material is removed by sharp hand instrument BP knife .
-Cement then coated with:
-light curable bonding agent
-Vaseline
This prevent loose or gain of water . dehydrated restored cement become weak due to microcracks.

54. FINISHING
Before dismissing the patient , apply one or more layer of protective agents .
GIC is not advised in patient with xerostomia , with mouth breathing habits (restoration are susceptible to dehydration) .

55. Occlusal caries on mandibular 1st molar

56. Caries excavation using spoon excavator

57. Completed caries excavation

58. CEMENT PLACED

59. Excess cement removed

60. Finishing done

61. LOSS OF GLOSS OR SLUMP TEST

62. USES

63. For luting
For restorations
Liners and bases
Fissure sealants
Orthodontic purpose
Core build up
Intermediate Restorations
Adhesive Cavity Liners (Sandwich Technique)
ART (Atraumatic Restorative Technique)
Restorations for deciduous teeth

64. Luting Agents Excellent for permanent cementation of crowns, bridges.
Releases fluoride reduces sensitivity by giving a firm
foundation for composites.
Fast setting - low film thickness & low viscosity.
P/Lratio………… 1.5:1
Typical Physical Properties:
Mixing Time: 15 seconds
Setting Time: 2 minutes
Working Time: 2 minutes

65. Luting agent

66. Orthodontic Bracket Adhesives
Most commonly used .
They bond directly to tooth by the interaction of Polyacrylate ions and hydroxyapatite crystals, thereby avoiding acid etching.
Anticariogenic effect -
fluoride releasing ability.

67. Pit and Fissure Sealants
Cements were found to be unsuitable for use as sealnts if the fissures were less than 100µm wide.
The material is mixed to a more fluid consistency to allow flow into the depths of the pits & fissure of the posterior teeth.

68. Carious pit & fissures on mandibular molar

69. Conditioner applied

70. Placement of the cement

72. They can be used as base for both composite resin and amalgam.
Liners and Bases
GICs have a number of advantages as cavity lining as they bond to dentine and enamel and release fluoride
-prevent decay & therefore minimizing the chances of appearance of secondary carries
-promote the formation of secondary dentine.
They can be used as base for both composite resin and amalgam.

73. GIC as a Base ( P/L ratio-3:1)

74. Class III cavity preparation in 32 -Liner placed for pulp prottection ( P/L ratio – 3:1 )

75. GIC as a lining – 0.5mm thick

76. For Core Build Up
Silver containing GICs (cermet, Ketac Silver, Espe,GMbH or 'miracle mix' of GIC &unreacted amalgam alloy have been used.
Cermet used to fill deciduous teeth .
Addition of Ag radiopacity to diagnose secondary caries.
To protect a GIC core crown margin should completely embrace 1-2 mm of sound tooth structure cervically.
Extension of crown margin -ferrule effect
Advantages:
to tooth Intrinsically adhessive
Fluoride release - freedom from 2° decay
Similar coefficient of thermal expansion

77. DEVELOPING
A CORE

78. Intermediate Restorations
Due to inherent adhesive nature & brittleness
To restore loss of tooth structure from the roots of teeth [cervical abrasion cavity-product of over zealous tooth brushing]
Used frequently as in non-undercut cavities, to ensure their retention

79. Deep caries

80. Temporary restoration - GIC

81. Adhesive Cavity Liners (Sandwich technique)
Involves using GIC as dentin replacement and a
composite to replace enamel
Surface should be coated either with an unfilled resin or a DBA to optimize attachment.

82. ART (Atraumatic Restorative Treatment)
The technique uses simple hand instruments (such as chisels &excavators) to break through the enamel & remove caries
The cavity is loaded using cotton rolls.
Then residual cavity is restored using a modified GIC.
These GICs are reinforced to give increased strength under functional loads and are radio opaque.

83. Restorations for Deciduous Teeth
Due to high fluoride release ,minimal cavity preparation & adhesion to dental hard tissue.
Restoring carious teeth is one of the major treatment needs of young children.
And because they require a short time to fill the cavity, Glass ionomer cements present an additional advantage.

84. PROPERTIES

85. Film Thickness than that of zinc phosphate cement and is
The film thickness of GICs is similar to or less
than that of zinc phosphate cement and is
suitable for cementation.

86. MECHANICAL PROPERTIES
Compressive strength – 150 mPa
Tensile strength – 6.6 mPa
Hardness – 49 khn
The resin-modified materials have been shown to have significantly higher tensile strengths and lower modulus of elasticity than the conventional materials.

87. ADHESION Good adhesion to enamel and dentin.
Bonding occurs between exchange of ions .
Some degree of bond is also developed between GI & collagen fibres of dentin.
Bond to enamel more than dentin , due to its high inorganic content and homogenesity .

88. ION EXCHANGE ADHESION BETWEEN TOOTH & CEMENT

89. AESTHETICS Lack translucency and have rough surfaces texture .
Inferior to silicate and composite .
Lack translucency and have rough surfaces texture .
Rough surface texture .

90. Margin Adaptation and Leakage
The coefficient of thermal expansion of conventional GI is close to that of dental hard tissue- so good margin adaptation of GI restorations.
Shear bond strength of GIC doesnt approach that of dentin bonding agent, resin-modified GIC exhibit microleakage .
This may be partly because their coefficient of thermal expansion is higher than conventional materials, though still much less than composite

91. BIOCOMPATIBLITY High degree of compatibility to living tissue
Polyalkenoic acid with high molecular weight is difficult to penetrate throught dentinal tubules .
Induce secondary dentin formation in mechanically exposed pulp .
In deep cavities Ca(OH)2 should be used to prevent post operative sensitivity .

92. RESISTANCE TO PLAQUE- Lack of plaque build up relative to adjacent teeth

93. ANTICARIOGENIC PROPERTIES
GIC is considered as a fluoride reservoir
Remineralisation of tooth structure due to release of Ca , PO4 and F ions
Streptococcus mutans is unable to thrive in the presence of F ions . so low accumulaton of plaque .
Minimize the white spotting and decalcification which is seen around orthodontic brackets .
Orthodontic bands on posterior teeth – luting agent of choice is GIC

94. FLUORIDE RELEASE

95. Fluoride re-uptake & release-after recharging with NaF gel

96. WATER BALANCE Susceptible to both water loose and water uptake.
Type 3 cement remains susceptible to water uptake for at least one hrs to 25 hrs after placement.
Resin modified G I were developed to overcome this problem.

97. CLINICAL IMPORTANCE
GIC susceptable to dehydration should be coated with varnish during dental procedure .
Contraindicated in mouth breathers and xerostomia patients due to dehydration .
Failure to protect with matrix / varnish / resin bond agent will result in chalky / crazed surface .
Decreased P/L ratio gives chalky surface .
Liquid with PAA not to be refrigerated which increases viscosity.

98. DISADVANTAGES OF CONVENTIONAL GIC
Short working time
Sensitivity to moisture exposure
Dehydration during setting.
Lower cohesion strength.
Less resistence to abrasion and wear than composite .

99. MODIFICATION OF
GIC

100. Resin modified GIC .
Metal modified GIC .
Fast setting materials .
Water settable GIC / anhydrous .
Compomers .

101. RESIN
MODIFIED
GIC

102. They also retain the acid – base reaction .
Cement are light cured by adding 5% resin
matrix to GIC .
They also retain the acid – base reaction .

103. RESIN MODIFIED GIC

104. COMPOSITON Ion leachable glass ( fluoro alumino silicate glass )
Polymerisable resin.
Photo initiator or chemical initiator or both .

105. LIQUID PAA H2O Methacrylate monomer .
Hydroxy ethyl methacrylate monomer (HEMA) .
The acid base raction will continue even in the absence of light activation .

106. Clean lesion with pumice & water

107. Condition with 10% poly acrylic acid for 10sec

108. Apply pressure during placement to minimise porosity & good wetting of the tooth

109. Trimming & contouring under air – water spray

110. PROPERTIES Microleakage more than GIC due to polymerization .
Good anticariogenic property due to increased F content.
Pulpal response mild .
Good esthetics .

111. USES
Class 1
Class 2
Class 5
For repair of cavities .

112. Class V non carious lesion restored with RMGIC

113. METAL MODIFIED
GIC
Miracle mix
Cermet

114. CERMET Filler particles are added………… To improve Strength
Fracture toughness
Resistence to wear

115. CERMET REPAIR ON BUCCAL CUSP OF BICUSPID HAS BEEN IN PLACE FOR 6years & APPEARS STABLE

116. Metal modified GIC

117. MIRACLE MIX
Also called silver alloy admix .
Spherical amalgam alloy powder mixed with type II GIC .
Not used in anterior teeth – due to radio opacity and metallic color .

118. Miracle mix

119. CERMET
Ag particles are bonded to glass particles by sintering ( fusion at high temp)
USES
Alternative to amalgam and composite .
In core build up in grossly destroyed
teeth .

120. PROPERTIES Excellent anticariogenic property due to F ions.
More resistance to wear than GIC.
Poor esthetics –radiopaque and gryeyish in color. .

121. FAST SETTING MATERIALS
Glass in these cements has been chemically modified during manufacturing to decrease the Ca2+ content and thus limit the production of Ca-poly alkeonate chains which are highly water soluble .
Faster maturation of setting reaction .
Decrease the translucency .

122. WATER SETTABLE GIC (ANHYDROUS)
Polyacrylic acid co-polymer is freeze dried and coated to powder particles.
The liquid part is water or water with tartaric acid.
When powder is mixed with water the polyacrylic acid goes in to solution to form liquid acid.
Cements undergo chemical reaction.
Cements set faster than normal cement.
Have improved physical properties.

123. COPOMER (POLYACID MODIFIED RESIN )
Hybridisation of composite and glass ionomer
Composite + ionomer = copomer
Variable degree of dehydrated polyalkenoic acid incoperated with filler .
The setting reaction is light activated .
Subsequent absorption of water from saliva into restoration will release small amount of fluorides

124. Have minimal steps in placement. Aesthetically pleasing.
Adhesive system is based on acid etch or resin bond system and no ion exchange adhesion.
Used in children.
Have minimal steps in placement.
Aesthetically pleasing.

125. Finished case

126. TUNNEL RESTORATION First discribed in 1963
Conservative alternative cavity preparation in primary molars.
Indication
Small proximal caries with out involvement of marginal ridges

128. SANDWICH TECHNIQUE
GIC is sandwiched between tooth and composite resin.
Used in case of deep carious lesion.
ADVANTAGE
Etching avoided in deep caries- avoid pulpal
irritation.
Better strength is achieved .
Prevent recurrent caries due to F ion release .
Chemical bonding to tooth achieved by GIC .

130. Closed sandwich restoration
Open sandwich restoration
Closed sandwich restoration

131. Lamination with amalgam
Combination of GIC with amalgam
To with stand heavy occlusal load.
STEP –I , A strong GI base(auto cured or resin modified) is applied first.
Fine layer of 45% poly acrylic acid applied over cement – ensure chemical bonding.
STEP II , Pack amalgam over this.
Mechanical interlocking occure between two

132. STEP II……………
…………STEP I

133. CONCLUTION….
No one material is universal and it is unlikely that such an ideal material limitations, bt each one , used to its full potential , has aplace in restorative dentistry.there have been 20years of close clinical observationof GIC

134. Text book of pedodontics - Shobha
Tandon
Preservation &restoration of tooth structure - Graham J Mount
Text of pediatric dentistry - S.G.Damle
Pediatric dentistry,infancy through adolescence
- Pinkham
Dentistry for the child & adolescent
- Mc Donald,Avery,Dean
Sturdevant”s Art & Science of Operative Dentistry

135. THANK YOU