Sandwich technique used in Restorative Dentistry

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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