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SturdevantSturdevant ‘s Art & Science of Operative Dentistry, ‘s Art & Science of Operative Dentistry, 44thth Ed. Ed. –– Chapter Chapter 20 20 page page 185-186

Dr. Hatem M. El-Damanhoury, BDS, MS, PhD, ABOD

Assistant Professor

Department of General and Specialist Dental Practice

AMALGAM DEFICIENCIESAMALGAM DEFICIENCIES

•• Amalgam is not adhesiveAmalgam is not adhesive

•• Restorations are passive and do not significantly Restorations are passive and do not significantly strengthen remaining tooth structurestrengthen remaining tooth structure

•• Mechanical retention/resistance form is provided Mechanical retention/resistance form is provided at the expense of tooth structureat the expense of tooth structure

•• Microleakage is present until corrosion seals the Microleakage is present until corrosion seals the cavocavo -- surface interface (process is much slower in surface interface (process is much slower in highhigh--copper amalgams).copper amalgams).

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Rationale For Amalgam BondingRationale For Amalgam Bonding

• Resin cement 4-META (4-methyloxy ethyl trimelliticanhydride) is placed over the prepared tooth surface (several costs).

• amalgam is packed directly into the uncured resin cement.

• forcing the glass fillers and resin matrix to intermingle with the amalgam.

• These materials harden together in an interlocking matrix.

• provides better bond strength of amalgam to dentin, reinforce the restored tooth and reduces microleakage and sensitivity

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ADVANTAGES OF RESIN BONDED AMALGAMADVANTAGES OF RESIN BONDED AMALGAM

1.1. Minimize or eliminate intial microleakageMinimize or eliminate intial microleakage

2.2. Enhance traditional resistance and retention Enhance traditional resistance and retention methodsmethods

3.3. Increase the fracture resistance of the restored toothIncrease the fracture resistance of the restored tooth

4.4. Permit more conservative restorationsPermit more conservative restorations

5.5. Decrease marginal breakdown and ditchingDecrease marginal breakdown and ditching

6.6. Reduced incidence of postoperative tooth sensitivity Reduced incidence of postoperative tooth sensitivity

7.7. Marginal Deterioration of bonded interface can be Marginal Deterioration of bonded interface can be compensated by the precipitation of amalgam compensated by the precipitation of amalgam corrosive products.corrosive products.

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IndicationsIndications

•• Supplementing mechanical retention feature in Supplementing mechanical retention feature in Large, complex amalgam restorations especially Large, complex amalgam restorations especially those replacing cusps.those replacing cusps.

•• When an improved initial seal is needed, such as When an improved initial seal is needed, such as after a direct or indirect pulp capping procedure in after a direct or indirect pulp capping procedure in tooth being restored.tooth being restored.

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Bonded Amalgam Technique Bonded Amalgam Technique 1.1. Rubber dam isolation Rubber dam isolation

2.2. Cavity Preparation. Cavity Preparation.

3.3. Apply conditioner (etchant) to enamel and dentinApply conditioner (etchant) to enamel and dentin

4.4. Rinse and dry lightly prior to Matrix band Rinse and dry lightly prior to Matrix band placement.placement.

5.5. Apply dentin primer/sealer.Apply dentin primer/sealer.

6.6. Apply the chemicallyApply the chemically--cured resin bonding linercured resin bonding liner

7.7. Apply lubricated matrix band and wedges Apply lubricated matrix band and wedges

(Double matrix technique may be required). (Double matrix technique may be required).

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8.8. Apply the chemicallyApply the chemically--cured resin bonding linercured resin bonding liner

9.9. Condense the amalgam immediately into the wet Condense the amalgam immediately into the wet liner before it cure.liner before it cure.

10.10. Burnishing and Initial Carving.Burnishing and Initial Carving.

11.11. Remove matricesRemove matrices

12.12. Use scalpels and sharp chisels to carve any resin at Use scalpels and sharp chisels to carve any resin at proximal margins and rotary finishing burs at proximal margins and rotary finishing burs at OcclusalOcclusal margins.margins.

13.13. Remove Rubber dam.Remove Rubber dam.

14.14. Adjust occlusion.Adjust occlusion.

15.15. Burnishing.Burnishing.

16.16. Finishing and polishing after Finishing and polishing after 24 24 hours.hours.4/14/2010 8Hatem El-Damanhoury

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