Operative One -- Dental Composite/Class Ionomer (RMGI) Sandwich Technique: Feitosa

Review Pulp Protection: Selective to firm dentin + liner =

Indirect pulp capping

Review Pulp Protection: Selective to soft dentin + Theracal/Liner =

Incomplete caries removal

Review Pulp Protection: Tertiary Dentin =

Dentin Bridge (direct pulp capping)

Review Pulp Protection: Secondary Dentin =

Physiological Dentin (slow production)

Sandwich technique definition

Layers of GI (conventional or resin modified) between dentin and permanent restorative material (resin-based composite)

GI and RMGI biocompatibility

Dentin replacement - GI has similar thermal conductivity and coefficient of thermal expansion

Fluoride release helps avoiding recurrent caries

Chemical bonding to dentin + Higher biocompatibility

Glass ionomer is less sensitive to saliva/blood contamination than RBC

Two types of sandwich technique

Close

Open

Close Sandwich Technique (IMAGE)

Open Sandwich Technique (IMAGE)

Close sandwich technique: Laying of

Two directly placed materials one covering the other

Close sandwich technique: Dentin is covered by a base of

GI or RMGI

Close sandwich technique: GI or RMGI is completely covered by

the overlaying restoration

Close sandwich technique: The base is placed

internally and completely surrounded with a second material

Close sandwich technique: What aspect of the glass ionomer is exposed to the saliva

none

Indications for a close sandwich technique

Pulp protection

- Selective caries removal

- Preparation extends very close to the pulp

- Fluoride release promotes affected dentin

Remaining enamel at the gingival margin

Close Sandwich Technique Steps

Preparation = complete tooth preparation

Rinse and dry = Rinse and dry, don't desiccate, leave dentin moist

Apply GI/RMGI = Place GI/RMGI over pulpal and/or axial wall

Check margins = Be sure not to place GI over any margins or on enamel

Etch and rinse = Phosphoric acid etch and rinse

Prime = Prime remaining exposed dentin and GI

Final restoration = Place adhesive then RBC resin composite, or other permanent restorative

Clinical case: closed sandwich technique image

Open Sandwich technique: Layering of two directly placed materials where

both are exposed to saliva

Open Sandwich technique other terminology

bonded base technique

Open Sandwich technique: Indications

Restoration of deep cervical lesions with dentin or cementum margins (severely damaged teeth with no enamel on the cervical margins)

Need material that contains fluoride to reduce potential recurrent caries (high risk patients)

The selective material for the open sandwich technique is RMGI

WHY RMGI

Superior Mechanical proterties than GI

Can be contoured and polished very similar to resin based composite

Stronger in acidic environment

Conventional GI have poor maintenance of anatomical form

Conventional GI suffers rapid surface degradation

Conventional GI doesn't present optimal esthetics

Open Sandwich technique Step

Preparation = complete tooth

Rinse and dry = rinse and dry, don't desiccate, leave dentin moist

Apply RMGI = Place RMGI over cervical and/or axial

Light cure = Light cure your RMGI

Etch and rinse = Selectively etch and rinse

Prime = primer then adhesive - light cure

Final restoration = place RBC resin composite to fill rest of prep

Clinical case open sandwich technique image

SUMMARY: Close Sandwich Technique -- Indications

Pulp protection (Enamel Margin)

SUMMARY: Close Sandwich Technique -- Contact with saliva?

No

Closed to the oral environment

SUMMARY: Close Sandwich Technique -- Surfaces

Axial and pulpal walls

SUMMARY: Close Sandwich Technique -- Material

Conventional GI RMGI

SUMMARY: Open Sandwich Technique -- Indications

Deep cervical lesions with dentin or cementum margins

High-caries risk pt

SUMMARY: Open Sandwich Technique -- Contact with saliva

Yes open to the oral environment

SUMMARY: Open Sandwich Technique -- Surfaces

Any (except surfaces under occlusal forces)

SUMMARY: Open Sandwich Technique -- Material

RMGI