Dental Amalgam Revision

Learning Outcomes

By the end of thisinteractive session you should be able to:

  • Describe the aims of amalgam bonding
  • Describe thestages in amalgam bonding
  • Adequately place a bonded amalgam in a plastic simulated tooth


Amalgam

Dental Amalgam is one of the oldest materials still used in direct restorations. Amalgam is an alloy (an alloy is a mixture of two or more elements).

Which one of the following elements is included in dental amalgam?

Tin is one of the elements included in dental amalgam?

Select which of the elements below is/are included in dental amalgam?

Select which of the elements below is/are included in dental amalgam?



Advantages of Amalgam
Disadvantages of Amalgam
Cost-effective Unsightly restorations
Less technique-sensitive than composite resin Does not bond to tooth substance (requires mechanical retention and resistance)
High clinical survival rates (Good durability) Relatively low tensile strength, weak in thin sections
Fewer allergic or hypersensitivity reactions than composite resin Concerns regarding mercury as a potential toxin and environmental contaminant
 Strong evidence base  

 

Go now and view article Dentistry Update 2006; 33: 094 - 098. This paper discusses that dental amalgam is still a viable restorative material. It also outlines the principles for placing better amalgam restorations.

Once you have read the paper you should attempt the associated questions below.

Question:

What has an effect on clinical longevity of amalgam?

Your Answer:
Correct Answer:
Composition of the alloy.
Question:

Can you name the elements and the percentage of each of the elements related to longevity?

Your Answer:
Correct Answer:
  • Silver - 58%-70%
     
  • Tin - 18%-30%
     
  • Copper - 12%-30%
     
  • Zinc - 0.5%-1%
Question:

Triturition time is usually set by the manufacturer. Is amalgam usually over-titurated or under titurated? What are the consequences?

Your Answer:
Correct Answer:
Usually over triturated resulting i a hot, quickly setting amalgam.
Question:

Condensation - what is the main purpose of condensation of amalgam?

Your Answer:
Correct Answer:

To remove mercury from the restoration, the excess mercury rises to the surface during condensation.

Secondly to improve marginal adaptation and elimination of voids. 

Question:

When carving the restoration, what area is often over-looked? why is it so important?

Your Answer:
Correct Answer:
Interproximal area is often over-looked. By overlooking the interproximal area we increase the likelihood of periodontal disease.
Question:

Is it critical to polish amalgam restorations? What are the related disadvantages?

Your Answer:
Correct Answer:
Polishing amalgams is no longer routine but can improve the appearance of amalgam restorations. Polishing can cause the generation of heat which may cause the surface to degenerate.