Glass ionomer cements are tooth-colored, fluoride-releasing restorative materials that bond chemically to tooth structure. They were originally developed in 1972 and are called glass ionomer cements because the powder component is a glass and the setting reaction involves an ionic bond. They have favorable properties like fluoride release and recharge, a coefficient of thermal expansion similar to tooth, and bond chemically to enamel and dentin. However, their disadvantages include opacity, poor wear resistance, brittleness, and weak tensile strength. Several modifications have been developed to improve upon their weaknesses.

1. PREPARED BY: KRITISHA ACHARYA

2. Glass Ionomer Cements are adhesive tooth colored
anticariogenic restorative materials which were originally used
for restorations of eroded areas.
● First usable GIC was formulated in 1972 by Wilson & Kent
● Named as GIC: The powder is a type of glass & setting
reaction & adhesive bonding to tooth structure is due to
ionic bond
● Also called as Biomimetic material
● Synonyms: poly(alkenoate) cement , GIC , ASPA(Alumino
silicate polyacrylic acid)

3. ● Low solubility
● Coefficient of thermal expansion similar to dentine
● Fluoride release & fluoride recharge
● High compressive strengths
●Bonds to tooth surface by primarily chemical (
calcium-carboxyl groups) , micromechanical
● low flexural strength

4. ● Low shear strength
● Dimensional change ( slight expansion) i.e shrinks on
setting , expands with water sorption
● Brittle
● Lacks translucency
● Rough surface texture
● Biocompatible to tissues

5. GIC HYBRID COMPOSITE
● Compressive strength(mpa) : upto 200
● Tensile strength(mpa) : 15
● Modulus of elasticity(Mpa) : 20000
● Coefficient of thermal expansion : 10.2-11.4
● Thermal diffusivity : 0.198
● 350-500
● 34-62
● 13500-18000
● 25-38
● 0.675

6. 1. A/C to Philips
● Type 1 : Luting
● Type 2 : Restorative
● Type 3 : Liner and base
2. A/c to Sturdvent
● Traditional or conventional
● Metal modified GIC : Ceremets & Miracle mix
● Light cured GIC
● Hybrid (resin modified GIC)
● Polyacid modified resin composites

7. A/c to intended applications
● Type 1 : Luting
● Type 2 : Restorative
● Type 3 : Fast setting lining
● Type 4 : Fissure sealants
● Type 5 : orthodontic cements
● Type 6 : core build up material
● Type 7 : Command set
● Type 8 : GIC for ART
● Type 9 : Geriatric and pediatric

8. 1. LIQUID
● Polyacid ( Acrylic,maleic , itaconic ) : increases reactivity of
liquid , decrease viscosity & reduce tendency for gelatin
● Water : medium of reaction & hydrates reaction products
● Comonomer :D-tartaric : improves handling characteristics,
increases working time & shortens setting time
● Recently added : poly vinyl phosphoric acid

9. 2. POWDER
● Alumina : 16.6% .Forms the skeletal structure & increases
opacity
● Silica : 29% . Increases translucency
● Calcium fluoride : 34.2% . Increases opacity & act as flux
● Aluminium phosphates : 9.9%. Decreases melting
temperature & increase translucency
● Cryolite : 5% . Increases opacity & act as flux
● other ions : sodium , potassium , calcium.
● Fluoride : decrease fusion , anticariogenecity & increase
translucency

10. 1. LEACHING
2. CALCIUM CROSS - LINKS
3. ALUMINIUM CROSS - LINKS
4. SODIUM & FLUORIDE IONS
5. HYDRATION
6. SILICA GEL SHEATH

11. 1. CONDITIONING OF TOOTH SURFACE :
Tooth surface is cleaned using cotton pellet & pumice
slurry and acid etching is done with 37% phosphoric acid.
● Conditioning : 10% polyacrylic acid or 37% phosphoric acid
for 10-20 sec & rinse with water for 20 sec.Deep cavities
should be protected by dab of calcium hydroxide.
● It should be dried and kept free from saliva or blood

12. 2. PROPORTIONING AND MIXING
● Powder / liquid ratio : varies according to type of GIC
used.manufacturers recommended ratio should be
followed. Low P/L ratio reduces mechanical properties and
increase chance of cement degradation.Moisture alters the
acid water balance.
● MIXING
Manual mixing : powder and liquid is dispensed just
prior to.mixing.Cool dry glass slab is used and powder is
divided into 2 or more increments.Material should not be
spread over large area.Increments are mixed using swiping
and folding technique. Mixing time : 30-40 sec.

14. A good mix should have glossy surface ( indicates presence of
residual polyacid )
Powder : liquid ratio = 1.5:1 for luting & 3:1 for restoration
MECHANICAL MIXING
GIC supplied in capsules form containing preproportioned
powder and liquid is mixed in an amalgam triturator.The
capsule has a nozzle so as the mix can be injected directly into
cavity or crown

15. ● GIC is sensitive to air and water. So it should be protected
from moisture contamination as well as drying during
setting and few days after setting using a preshaped matrix.
● Matrix is removed after complete set.The cement surface is
again protected from.drying with varnish , an unfilled light
cured resin bonding agent and cocoa butter or petroleum
jelly
FINISHING
Excess is trimmed using hand instruments . Further finishing if
required is done after 24 hrs

16. 1. Non stress bearing areas
2. Class 3 & 5 restorations in adults
3. Class 1 & 2 restorations in primary dentition
4. Temporary or " caries control" restorations
5. Crown margin repairs
6. Cement base under amalgam , resin , ceramics , direct &
indirect gold
7. Core build ups when at least 3 walls of tooth are remaining.

17. 1. High stress applications
2. Class 4 & 2 restorations
3. Cusp replacement
4. Core build ups with less than 3 sound walls remaining

18. 1. Bonds to enamel & dentin
2. Significant fluoride release , can be recharged
3. Coefficient of thermal expansion similar to tooth structure
4. Tooth colored
5. Low thermal conductivity

19. 1. Opacity higher than resin
2. Less polishability than resin
3. Poor wear resistance
4. Brittle , poor tensile strength
5. Poor longevity in xerostomic patients

20. 1. METAL MODIFIED GLASS IONOMER
● Silver alloy admix(silver amalgam alloy particles mixed
with glass particles)
Increases flexural strength by addition of metal powder or
fibers : found by Sced and Wilson.
Simmons suggested mixing amalgam alloy powder to cements
and named it as "Miracle Mix".It is used for core building and
treating mouth with high caries incidence.But have poor
esthetics and donot burnish.

21. ● CERMET( GLASS SINTERED WITH SILVER): by McLean
& Gasser
Improved resistance to abrasion.
High flexural strength but still insufficient to replace amalgam
alloys
Use is confined to ow stress bearing cavity preparation.

22. 2. RESIN MODIFIED GLASS IONOMER
● VISIBLE LIGHT CURE GLASS IONOMERS , HYBRID
GLASS IONOMERS
To overcome moisture sensitivity and lack of command cure,
an attempt have been made to combine glass ionomer
chemistry with well known chemistry of composite resins.
Favorable physical properties similar to composite resin with
basic features of convenctional GIC.

23. These are dual cure if only one polymerization is used.If both
mechanisms are used they are considered to be tricured.
In their simplest form , these are GICs with addition of a small
quantity of a resin such as hydroxyethyl methacrylate or Bis -
GMA in liquid.
More complex materials have been developed by modifications
of polyacid with side chains that can be polymerized by a light
curing mechanism
1st commercial RMGIC were liners , vitrebond

24. 3.HIGH STRENGTH "PACKABLE" OR "HIGH VISCOSITY"
GLASS IONOMER
● Used for ART
● Alternative to amalgam for posterior preventive
restorations.
● Examples : Fuji IX and Ketac molar
● set by conventional neutralization reaction
● Setting is rapid , early moisture sensitivity is considerably
reduced
● Solubility in oral fluids is very low.

25. ● Polyacid modified GIC / Compomer
● Self hardening GIC
● Low viscosity / flowable GIC
● Condensable GIC / High viscosity GIC
● New fluoride releasing GIC : fluoride charged GIC & low pH
" SMART MATERIAL"
● Chlorhexidine impregnated GIC
● Proline containing
● CPP - ACP containing

26. ● Zirconia containing
● Nano Bio ceramic modified
● Calcium Aluminate
● Bioactive glass
● Fibre reinforced GIC
● Giomer
● Hainomer

27. ● Textbook of Pediatric Dentistry 3rd Edition ( Nikhil
Marwah)
● Basic Dental Materials 4th Edition ( John J. Manappallil)