Sandwich technique

Sandwich technique used in Restorative Dentistry

1. Sandwich Technique 4/26/2016 1

2. Outline Introduction Types Technique Indications and Contraindications Advantages and Disadvantages Conclusion References 4/26/2016 2

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. 4/26/2016 3

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 4/26/2016 4

5. Types Closed sandwich technique: The underlying material does not come into contact with the oral cavity. 4/26/2016 5

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. 4/26/2016 6

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. 4/26/2016 7

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 . 4/26/2016 8

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 4/26/2016 9

10. How to do the Sandwich Technique 4/26/2016 10

11. 1. Prepare Class I/II cavity 4/26/2016 11

12. 2. Condition the dentin and enamel surfaces using an acid conditioner (preconditioning) 4/26/2016 12

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. 4/26/2016 13

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) 4/26/2016 14

15. 4. Etch the enamel and GIC 4/26/2016 15

16. 5. Apply bonding agent 4/26/2016 16

17. 6. Light cure and apply composite resin in increments 4/26/2016 17

18. 7. After finishing and polishing… 4/26/2016 18

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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. 4/26/2016 20

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 4/26/2016 21