Amalgum is alloy mercury with another metal or metals.
- Ag 58-70%
- Sn 18-30%
- Cu 12-22%
- Zn 0.5-1%
Liberated hydrogen can cause delayed expansion of amalgam.
- Conventional amalgam-Less than 6% copper
- Copper enriched amalgams-6-30% copper
Mercury in dental amalgam is not poisonous. When mercury is combined with other materials in dental amalgam, its chemical nature changes. so it is essentially harmless.
· Least expensive materials to a fill a cavity.
Alternatives to amalgam:
· cast gold restorations
· Composite resins are more costly.
Mercury can be found in:
- Alert-during training we need to observe good Hg hygiene practice
- Ventilation-fresh air exchanges AC plants act as Hg reservoirs. Therefore filters should bee replaced with time.
- Surgery atmosphere should be checked periodically
- Do not carpet the floor. Sheet flooring up to 10cm of wall.
- Hg storage-Unbreakable, tightly sealed, and store away from heat.
- Use single use capsule sealed during amalgamation
- Avoid removal of excess Hg and use correct Hg: Alloy ratio
- Use a totally enclosed amalgamator
- Hg dispensers handle with care and heck regularly for any leaks
- Check orifice for residual Hg.
- Hg should not touch with bare hands
- All amalgam scrap and Hg stored in a tight container and discard under radiographic fixer solution.
- Spilled Hg immediately cleaned and placed in a scrap jar
- Do not heat Hg or amalgam and instruments, clean them before heat sterilization
- Do not use ultrasonic amalgam condensers
- Remove old amalgams and polish under copious air water spray and high volume evacuation exhaust outside the surgery
- Wear a mask
- All the abrasions and cuts in the skin should be covered prior to handling the amalgam
- Disposable material contaminated with amalgam disposed properly
- Waste water systems-place Hg traps
- Skin contaminated with Hg should washed thoroughly with soap and water
- Do not eat, drink, smoke inside the surgery
- If Hg toxicity problem suspected-urine analysis done for Hg.