3. AMALGAM word amalgam is derived from greek name
emolient which means paste.
3
Amalgam -An alloy containing mercury⚫
Dental Amalgam - An alloy of mercury silver copper and
tin, which may also contain palladium, zinc and other
elements to improve handling characteristics and
clinical performance
⚫
Dental amalgam Alloy - An alloy of silver copper and tin
that is formulated and processed in the form of powder
particles or compressed pellets.
4. 4
STATEMENT ON AMALGAM
“No controlled studies have been published demonstrating systemic adverse
effects from amalgam restorations.”– FDI & WHO ; 1997
“Based on available scientific information , amalgam continues to be a safe and
effective restorative material.” – ADA ; 1998
“There currently appears to be no justification for discontinuing the use of dental
amalgam” – ADA ; 1998
6. 6
CLASSIFICATION
According to number of alloy metals :
1.Binary alloys ( Silver – Tin )
2.Ternary alloys ( Silver – Tin – Copper )
3.Quanternary alloys ( Silver – Tin – Copper – Indium )
7. Based on copper content :
• Low copper alloy -- < 6% copper (conventional alloy)
• High copper – 6.30% copper
1. Admixed alloy
2. Single composition alloy
Based on zinc content :
1. Zinc containing alloy -- > 0.01% zinc
2. Zinc free alloy -- < 0.01% zinc
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8. 1. Silver : Whitens the alloy , Decreases creep
Increases strength , Increases the expantion on setting
Increases resistance to tarnis
2. Tin : Reduce tarnish and corrosion
Reduce strength and hardness
3. Copper : Increases hardness and strength
Increases setting expansion
4. Zinc : Act as a deoxidiser and scavenger
Causes delay expansion in amalgam
FUNCTION OF EACH CONSTITUENT
9. ADVANTAGES
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• Ease of use, Easy to manipulate
• Relatively inexpensive
• Excellent wear resistance
• Restoration is completed within one sitting without requiring
much chair side time.
• Well condensed and triturated amalgam has good compressive
strength
10. DISADVANTAGES
• Unnatural appearance ( non esthetic )
• Tarnish and corrosion
• Metallic taste and galvanic shock
• Discoloration of tooth structure
• Lack of chemical or mechanical adhesion to the tooth structure
• Mercury toxicity
• Promotes plaque adhesion
• Delayed expansion
• Weakens tooth structure ( unless bonded ).
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13. CONCLUSION
Despite the long history and popularity of dental amalgam as a
restorative material, its use has been reducing in clinical practice
due to the aesthetic requirement of patients. However, dental
amalgam restorations are still a great option for some cases, such
as special patients and with the necessary caution, good sense and
within the knowledge and based on relevant studies, the teaching
and use of dental amalgam may continue in clinical cases in which
aesthetics is not the predominant factor.
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14. REFRENCES
1. McDonald A (2001) Advances and fixed in operative dentistry prosthodontics. Primary Dental Care 8:
13-16.
2. Rasines Alcatraz MG, Veitz-Keenan A, Sahrmann P, Schimidlin PR, IheozorEjiofor Z (2014) Direct
composite resin fillings versus amalgam fillings for permanente or adult posterior teeth. Cochrane
Database Syst Rev CD005620.
3. Phillips RW(1991) Science of dental materials (9th edn), W.B. Sauders Co, Philadelphia, USA. pp. 61-
67.
4. Mitchell RJ, Koike M, Okabe T (2007) Posterior amalgam restorations-usage, regulation, and longevity.
Dental Clinics North Am 51: 573-589.
5. De Souza JL, Nozawa SR, Honda RT (2012) Improper waste disposal of silvermercury amalgam. Bull
Environ Contam Toxicol 88: 797-801.
6. Burke FJ, McHugh S, Hall AC, Randall RC, Widstrom E, et al. (2003) Amalgam and composite use in UK
general dental practice in 2001. Br Dent J 194: 613-618.
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