1. Resin-modified Glass-ionomer Materials
Dent 5801 Operative Dentistry I
Oct 9th, 2007
Resin-modified Glass-ionomer Materials
Daranee Versluis-Tantbirojn
Division of Operative Dentistry
Department of Restorative Sciences

2. Learning objectives Students will be able to
Understand clinical behavior of glass-ionomers from the material viewpoint
Apply scientific information from the literature for clinical decisions about the use of glass-ionomers
Appropriately use glass-ionomers in restorative dentistry

3. + pendant methacrylate groups
Recall...
DENT 5351 Dental cements, Dr. Combe, Feb 2, 2007
+ pendant methacrylate groups
Polymerization
Resin-modified
glass-ionomer
Acid-base reaction

4. Background: Chemistry and setting reactions
polyalkenoic acids + calcium fluoroalumino silicate glass
+ methacrylate
copolymer
Glass
core
Tooth structure
Ca2+
Al3+ F-
CO-O-
-O-CO
PO43-
Siliceous hydrogel
Ca/Al polyacrylate
matrix
Conventional GIs
(Acid-based reaction)
Ca2+ = initial set (minutes)
Al3+ = final set (days, weeks, months)
Resin-modified GIs
Light initiated or autocure (set w/o light)
methacrylate
copolymer
(resin-modified GI)
Drawing adapted from
Albers HF 1996, Tooth-color Restoratives.

5. True glass ionomers Conventional or Resin-modified Mixing
‘self-cured’
‘light-cured’
Resin-modified
acid-base reaction
Mixing
Cure in the dark

6. ‘Hybrid ionomer composite’ (Geristore)
(Wilson & Kent 1972)
(Bowen 1963)
Glass ionomer
cement
Resin composite
Polyacid-modified
composite (compomer)
Resin-modified GI
‘Giomer’
‘Hybrid ionomer composite’ (Geristore)
True glass ionomers

7. Glass ionomers in restorative dentistry

8. Glass ionomers in restorative dentistry* *
Restorative
Fuji II LC
Fuji IX
Ketac Molar
Ketac Fil
(Filling)
Vitrebond
Lining * *
Vitrebond Plus
Ketac Bond
Fuji Lining
Luting
RelyX Luting
RelyX Luting Plus *
FujiPlus
FujiCem * *
presently used in Operative preclinic & clinic

9. Advantages of glass ionomers Compare with other cements
Ion exchange layer
Adhesion to tooth structures
Glass
core
Tooth structure
Ca2+
Al3+ F-
CO-O-
-O-CO
PO43-
Release ions (F-) affect balance between de/remin
‘Non-irritant’
Translucent
Better mechanical properties
Compare with other cements

10. Glass ionomers: Use with caution
Inadequate physical properties *
Sensitive to water gain/loss *
Esthetic compromise *
Anticaries property is questioned
Adhesion property is not comparable to composite + dentin adhesive
* More crucial if used as a permanent filling material

11. Major physical failure
GIs cannot be used as permanent restorative material in stress-bearing areas
Major physical failure
58 months
Bulk fracture
Marginal fracture
Poor anatomic form (wear)
Dissolution/disintegration
Clinical failure of class-II restorations of a highly viscous glass-ionomer material over a 6-year period: A retrospective study
Scholtanus JD, Huysmans MCDNJM
J Dent 2007;35:156-62
Esthetic compromise
Opaque
Surface finish

12. Sensitive to water gain/loss
Use with cautions
Sensitive to water gain/loss
Maintain water balance during initial setting
Resin-modified GI restoratives (GC Fuji II LC)
Resin protects cement from water
Fast-set GIs (GC Fuji IX)
Wait 3-6 min before polishing
Polish with water coolant to prevent dehydration
Apply unfilled resin to protect surface

13. How is it under clinical conditions?
Anticaries property is questioned?
In vitro anticariogenic potential of GIs is known
Adapted from Hicks
Plaque or acid medium
Vitrebond Plus/Z250
Z250
How is it under clinical conditions?

14. Anticaries property Questionable?
A systemic review shows no overall evidence for or against a treatment effect of inhibition of secondary caries by glass ionomer restoration
28 studies from 1970 to 1996; total of 3965 participants; high caries risk
5 positive studies
No secondary caries in GI; secondary caries in control
19 neutral studies
No secondary caries in either group
or secondary caries present in both groups
4 negative studies
Secondary caries in GI; no secondary caries in control
Randall RC, Wilson NH. J Dent Res 1999;78:
How would the data apply to present glass ionomers?

15. Anticaries property Questionable?
Glass ionomers reduce recurrent caries in high-risk patients who do not routinely use topical fluoride.
Restorations in xerostomic patients: composite or amalgam vs GI
Patients were instructed to use NaF gel daily
At 2 years recall:
No recurrent caries was found in the fluoride users
No recurrent caries associated with conventional GI
In fluoride non-users, 8 composite and 1 RMGI had recurrent caries & higher incidence of caries at amalgam cavosurface margins
McComb D, Erickson RL, Maxymiw WG, Wood RE
Operative Dentistry 2002;27:430-7
Haveman CW, Summitt JB, Burgess JO, Carlson K
JADA 2003;134:177-84

16. Use GI restorative material for caries control
G. Mount
67 Cl V composite and 65 Cl V glass ionomer cement
After 5 years, 1% of glass ionomer and 6% of composite restorations had become carious
Approximately twice as much marginal staining around the composite as around the glass ionomers.
Tyas MJ. Australian Dental Journal 1991; 36:236-9.
Cariostatic effect of glass ionomer cement: a five-year clinical study.

17. Adhesion property of glass ionomers
Bond strength (MPa)*
Enamel
Dentin
GI Restorative
~ 4-14
~ 4-10
Composite + adhesive
~ 30
~ 25
GI liner
~ 3-7
~ 4-10
GI luting cement
~ 6-10
~ 2-6
Metal
Porcelain
GI luting cement
~ 7-12 (sandblast)
~ 8-14 (Zr, Alumina)
Resin cement
+ adhesive
~ 15-25
~ 25 (etched porcelain
& ceramic primer)
* Shear mode; 3M and GC products; 3M Product Profiles

18. Bond strengths of glass ionomers are not comparable to composite + adhesive or resin cement
Should I use GI luting cement or resin cement?
Should I use GI restorative or composite?
Should I use GI liner or not?
What are the most likely errors that affect adhesion?
Other issues to consider related to adhesion:
post-operative sensitivity
microleakage
pulp protection

19. Studies showed that GI lutings did not cause post-op sensitivity.
GI luting vs Resin cement
Post-operative sensitivity was a problem with GI lutings in 1980’s–1990’s
Studies showed that GI lutings did not cause post-op sensitivity.
No differences between GICs (conventional & resin-modified) or a zinc phosphate luting cement
Kern M, Kleimeier B, Schaller HG, Strub JR. J Prosthet Dent 1996;75:159-62
Jokstad A. Int J Prosth 2004;17:411-6
Paste-paste resin-modified GI luting cement did not cause post- operative sensitivity (290 restorations in 268 patients) .
Yoneda S, Morigami M, Sugizaki J, Yamada T. Quintessence Int. 2005;36:49-53
The level of tooth sensitivity post-cementation (1-4 wks) was less than pre-operatively in both conventional and resin-modified GICs.
Smales RJ, Gale MS. Oper Dent 2002;27:442-6

20. Should I use GI luting cement or resin cement?
GI luting vs Resin cement
Post-operative sensitivity was a problem with GI because:
Dentin was desiccated
Anhydrous glass ionomer cement
Should I use GI luting cement or resin cement?
GI luting cement for indirect metal restoration (inlays, onlays, full gold crown) and PFM.
Simple application & easy clean up
Resin cement for esthetic indirect restorations (porcelain, ceramics, indirect composite) and indirect metal or PFM where additional retention is required (minimal tooth structure).
Indications

21. Example of instruction for use of a resin-modified glass-ionomer luting cement (3M RelyX Luting Plus)
Pulp protection if necessary
Clean tooth, rinse and lightly dry leaving tooth surface moist.
Remove excess cement at a waxy stage (after 2 minutes from placement)
Mix with spatula for 20 second
Working time 2.5 minutes

22. Should I use GI restorative or composite?
Clinical studies showed mixed results in Cl V retention
Folwaczny et al., 2001
Brackett et al., 2003
Onal and Pamir, 2005 86 81 70
Composite
RMGI
3 years
2 years
% Retention 55 96
100
References
However, deficiencies in color stability, anatomic form, or wear limit the longevity of glass ionomer restorations.
Post-operative sensitivity of composite restorations
Polymerization shrinkage
Microleakage
Sub-optimal bonding

23. Painful on pressure Composite leakage & Post-op sensitivity
Post-operative sensitivity
Composite leakage
& Post-op sensitivity
Anecdote:
No sensitivity after replacing composite with glass ionomer restoration
Painful
on pressure

24. Example of resin-modified glass-ionomer restorative (GC Fuji II LC)
Cavity conditioner (recommended for GC products)
Enhanced bonding by removing smear layer
Mild (25%) polyacrylic acid
Apply 10 seconds on dentin and enamel, rinse, blot. Surfaces should appear moist (glistening) before applying glass ionomer

25. However, GI liners prevent post-operative sensitivity.
Should I use GI liner?
Bond strength (MPa)*
Enamel
Dentin
Composite + adhesive
~ 30
~ 25
GI liner
~ 3-7
~ 4-10
Bond strength of GI liner is not comparable to composite
However, GI liners prevent post-operative sensitivity.
When GI liner (e.g., Vitrebond or Fuji Lining Cement) is applied to the deepest portions of Class I, II, and V tooth preparations before any bonding systems are used, clinicians have reported that it almost totally prevents postoperative tooth sensitivity.
Gordon J Christensen, JADA 2002;133:

26. Should I use GI liner? Less microleakage with GI liners
Class II amalgam restorations with GI liners had significantly less microleakage than did restorations with calcium hydroxide liners or dentin alone (without GI).
Rabchinsky J, Donly KJ. Int J Perio Rest Dent 1993;13:378-83
Marchiori S et al., Quintessence Int 1998;29:637-42
‘Dycal’ should always be covered with GI liner
Ca(OH)2 liner adversely affects bonding efficacy of dentin adhesive
Krejci I, Lutz F, J Dent 1990;18:263-70
Ca(OH)2 liners ‘wash out’ leaving a void underneath the restoration
Novickas D, Fiocca VL, Grajower R, Oper Dent 1989;14:33-9
How good is Dycal to withstand amalgam condensation?

27. Should I use GI liner? Do not use RMGI when pulp is exposed.
When in direct contact with exposed pulp,
Vitrebond triggered a persistent inflammatory reaction.
Am J Dent 2000;13:28-34
do Nascimento AB, Fontana UF, Teixeira HM, Costa CA
Biocompatibility of a RMGIC applied as pulp capping in human teeth
But GI liner is better than dentin adhesive in deep cavity.
Pulp response in deep class V composite restoration lined with Vitrebond was better than total-etched adhesive.
Dent Mater 2003;19:739-46
Costa CA, Giro EM, do Nascimento AB, Teixeira HM, Hebling J
Short-term evaluation of the pulpo-dentin complex response to a resin-modified glass-ionomer cement and a bonding agent applied in deep cavities.

28. How deep is deep? ~ 1 mm below DEJ* 1-2 mm from pulp*
>1 mm from DEJ*
0.5-1 mm from pulp*
(‘pinkish’)
GI liner optional
Etch & Adhesive
Composite
GI liner
Etch & Adhesive
Composite
Dycal
GI liner
Etch & Adhesive
Composite
* The numbers are arbitrary for illustration purposes.
It depends on the tooth, location, pulp recession, etc.

29. Example of resin-modified glass-ionomer liner (3M Vitrebond Plus)
Use clean Dycal carrier
Followed by etching, bonding, filling

30. Questions?