The sandwich technique involves using two restorative materials bonded together to restore a tooth. There are open and closed techniques, with the open technique exposing the underlying material to the mouth. Common materials used are glass ionomer cement or flowable composite as the underlying liner layer, which bonds to tooth structure and the overlying composite. It provides benefits like increased retention, fluoride release to prevent decay, and stress absorption. The technique is indicated for lesions with non-enamel margins or class II composites involving the gingival area. It involves conditioning, placing the liner, etching, bonding, and incrementally placing the overlying composite.

1. Sandwich Technique
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2. Outline
• Introduction
• Types
• Technique
• Indications and Contraindications
• Advantages and Disadvantages
• Conclusion
• References
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3. What is sandwich?
• Something resembling a sandwich;
especially composite structural material
consisting of layers often of high-strength
facings bonded to a low strength central core.
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4. • A restoration in a tooth in which two
restorative materials are used that are
chemically bound together.
• Here, a glass-ionomer or flowable composite
material is used as a liner under some
composite restorations.
Introduction
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5. Types
• Closed sandwich technique: The underlying
material does not come into contact with the
oral cavity.
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6. • Open sandwich technique: Usually used for
Class II restorations where the underlying
material forms part of the axial wall and is
exposed to the oral environment.
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7. Glass Ionomer Cement
• Benefits as a liner:
–Bonds both to the tooth structure and the
composite, increasing retention form and
providing better seal when used at non-
enamel margins.
–Fluoride in the GI material reduces
potential for recurrent caries.
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8. Flowable Composite
• Benefit as a liner:
–Acts as a shock absorber, distributing
stresses applied to the more rigid
composite
–May reduce some of the negative effects of
polymerization shrinkage.
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9. Indications of Sandwich Technique
• Lesions where one or more margins are in
dentin-like cervical lesions (class V)
• Class II composite restorations
• When any part of the gingival margin of class
II preparation has been extended past the CEJ,
and no longer has an enamel cavo-surface
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10. How to do the Sandwich Technique
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11. 1. Prepare Class I/II cavity
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12. 2. Condition the dentin and enamel surfaces
using an acid conditioner (preconditioning)
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13. • Function of conditioner:
–Creates stronger bond between tooth and
GIC
–Removes smear layer and debris from tooth
surface
• Citric acid and polyacrylic acid have been
used as conditioners.
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14. 3. Place an increment of GIC over the cavity
floor, extending up DEJ around the perimeter
of the preparation, or just short of the cavo-
margin at the base of proximal box (In Class II)
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15. 4. Etch the enamel and GIC
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16. 5. Apply bonding agent
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17. 6. Light cure and apply composite resin in
increments
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18. 7. After finishing and polishing…
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20. Conclusion
• It is recommended that the sandwich
technique be the restoration of choice when
proximal gingival margins extend beyond the
cementoenamel junction.
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21. References
• Art and Science of Operative Dentistry -
Studervant – page 304
• http://pocketdentistry.com/9-the-tooth-
coloured-restorative-materials-iii-glass-ionomer-
cements/
• Liebenberg W.. Return to the Resin-Modified
Glass–Ionomer Cement Sandwich Technique;
JCDA 2005; 71(10): 743-747.
• http://www.merriam-
webster.com/dictionary/sandwich
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