2. Bonded Amalgam Restorations
Learning Outcomes
By the end of this interactive session you should be able to:
- Describe the aims of amalgam bonding
- Describe the stages in amalgam bonding
- Adequately place a bonded amalgam in a plastic simulated tooth
Before completing this section you should view the Dental Amalgam Revision section.
Amalgam Bonding
Amalgam can be bonded to the tooth using an adhesive system. Potential benefits include:
- Decreased microleakage
- Decreased incidence of recurrent caries
- Decreased pulpal inflamation
- Decreased post-operative sensitivity
- Increased fracture resistance of the tooth
- Decreased cuspal deflection
- Treatment of cracked cusp
- Conservation of tooth substance
- Increased retention
Amalgam bonding requires more clinical time and is therefore more costly and more technique-sensitive. It is of use when additional retention and resistance features are required but where there is insufficient or weakened tooth tissue, in which to build in these features.
To download the associated PowerPoint presentation for this section click here.
The first Video clip shows a natural, carious tooth with a large cavity present, accompanying the clinical scenario is a radiograph of the tooth, showing the caries present. During your practical class you shall be using plastic teeth.
Click on each of the links below to view the video and then attempt to answer the questions after viewing the video.
Question:
When removing caries, why should you clear the margin first?
When removing caries, why should you clear the margin first?
Correct Answer:
Always clear around the margins of the caries first so that as you approach the pulpal area you are not at risk of infecting the sensitive pulp tissue with bacteria, from an active carious site.
Always clear around the margins of the caries first so that as you approach the pulpal area you are not at risk of infecting the sensitive pulp tissue with bacteria, from an active carious site.
Carious Dentine Question
Question:
Once all caries is removed, what should sound dentine look and feel like?
Once all caries is removed, what should sound dentine look and feel like?
Correct Answer:
It can be white or stained in colour but it should feel hard with the sharp probe.
It can be white or stained in colour but it should feel hard with the sharp probe.
Question:
Wedges are used with the matrix ban interproximally. Define interproximal.
Wedges are used with the matrix ban interproximally. Define interproximal.
Correct Answer:
Interproximal is the triangular area between teeth usually filled with the interdental papilla.
Interproximal is the triangular area between teeth usually filled with the interdental papilla.
Method of Bonding Amalgam Question
Remove the wedges and carefully remove the matrix system, supporting the amalgam with cotton wool in tweezers as you do. Finish with a ball ended burnisher and damp cotton wool.
Summary
Do you understand the indications for a bonded amalgam restoration?
- Heavily broken down coronal tooth structure
- High load bearing, large restoration core build-up for posterior teeth
- Difficult moisture control conditions for a posterior composite
Further Reading
A good review article from Dental Update: Staninec M; Setcos J C. Bonded amalgam restorations: current research and clinical procedure. Dental update 2003;30(8):430-4, 436.