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VOLUME 12 , ISSUE 3 ( May-June, 2011 ) > List of Articles


Revisiting Amalgam: A Comparative Study between Bonded Amalgam Restoration and Amalgam Retained with Undercuts

Indra Gupta, Satyendra Gupta, Anjali Kothari

Citation Information : Gupta I, Gupta S, Kothari A. Revisiting Amalgam: A Comparative Study between Bonded Amalgam Restoration and Amalgam Retained with Undercuts. J Contemp Dent Pract 2011; 12 (3):164-170.

DOI: 10.5005/jp-journals-10024-1028

Published Online: 01-06-2011

Copyright Statement:  Copyright © 2011; Jaypee Brothers Medical Publishers (P) Ltd.



To compare the retention of amalgam restorations in bonded amalgam restoration and restorations with undercuts.


With improvement in adhesive technology problem associated with conventional preparation for amalgam restorations mainly compromised resistance form of tooth structure have been largely overcome.

Materials and methods

Forty caries free extracted molars were used. A basic box preparation was done proximally with buccoproximal and linguoproximal walls diverging at 45° angle and the axial wall is 1.3 mm in dentin.

Group 1 – Teeth with basic box preparation.

Group 2 – Teeth with box preparation for bonded amalgam.

Group 3 – Teeth with box preparation and proximal retention grooves.

Group 4 – Teeth with box preparation and occlusal dovetail.

Group 1, 3 and 4 were restored with silver amalgam and group 2 restored with resin-bonded amalgam. All samples were subjected to simulated occlusal load against marginal ridge using a blunt stainless steel point in an Instron testing machine. The force in kilogram required to dislodge the restorations as well as the type and location of failure were recorded.


The main force required to dislodge the restoration was least in group 1 and 3 and maximum in group 2.


The in vitro study showed that the amalgam bonding technique, using an adhesive resin liner in proximal box form preparation, was more effective than either box form with proximal grooves or dovetails or proximal box only in providing resistance to displacement.

Clinical significance

Amalgam bonding eliminates the unnecessary removal of sound tooth structure during cavity preparations.

How to cite this article

Gupta I, Gupta S, Kothari A. Revisiting Amalgam: A Comparative Study between Bonded Amalgam Restoration and Amalgam Retained with Undercuts. J Contemp Dent Pract 2011;12(3):164-170.

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  1. The adhesive amalgam: Fact of fiction. Brit Dent J 1922;172:282,316-19.
  2. Retention of amalgam restorations: Undercuts versus bonding, Quintessence Int 1989;20(5):347-51.
  3. Cuspal failure of MOD restored teeth. Aust Dent J 1982;27(5):283-87.
  4. Effects of design of class II. Preparations on resistance of teeth to fracture. Oper Dent 1983;8:6-10.
  5. Effect of bonded amalgam on the fracture resistance of teeth. J Prosthet Dent 1992;53:257-20.
  6. Effect of prepared cavity on the strength of the teeth. Oper Dent 1981;6:2-5.
  7. In vitro evaluation of the use of resin liners to reduce microleakage and improve retention of amalgam restoration. Oper Dent 1992;17, 112-19.
  8. Extension for prevention: Items of interest 190123322-333.
  9. Approximal retentive grooves in cavities prepared for amalgam: Historical and current assessment. Oper Dent 198510100-03.
  10. Retention grooves for the class II amalgam restoration. Necessity or Hazard Oper Dent 1992;17:29-33.
  11. Modern class II amalgam cavity preparations. NZ Dent J 1972;68:132-38.
  12. Width of isthmus and marginal failure of restorations of amalgam. Oper Dent 1981;6:55-58.
  13. Failure of the margin of amalgams as affected by cavity width, tooth position, and alloy selection. J dent Res 1981;60:681-85.
  14. The facial slot preparation: A nonocclusal option for class II carious lesions. Oper Dent 1982;7:102-06.
  15. The influence of proximal retention grooves on the retention and existence of class II preparations for amalgams. J Am Dent Assoc 1975;91:1053-60.
  16. Clinical evaluation of interproximal retention grooves in class II amalgam cavity design. J Prosthet Dent 1967;17(6):596-602.
  17. Analysis of amalgam cavity design. J Prosthet Dent 1973;29(2):204-09.
  18. Clinical study of conservative designs for class II amalgams. J Dent Res 1988;67:06 (Abstract No. 1549).
  19. Fracture resistance of teeth with cl. II silver amalgam, posterior composite and glass cermet restorations. Oper Dent 19901542-47. Cited from Dr Dipti Desai, unpublished dissertation, Gujarat University 1992.
  20. Inhibition in vitro of caries around amalgam restorations by bonding amalgam to tooth structure. Oper Dent 1989;14(3):142-48.
  21. Effect of polymerization shrinkage on leakage of class II restoration. J Dent Res 67, abstracts of papers 1988;196, abstract 667.
  22. The relative shear bond strength of visible light-curing and chemically curing glass ionomer to composite resin. Quintessence Int 1992;20:521-24.
  23. Bonding of amalgam to tooth structure. Tensile adhesion and microleakage tests. J Prosthet Dent 1988;59(4):397-402.
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