What is the setting reaction of amalgam?
Table of Contents
- 1 What is the setting reaction of amalgam?
- 2 What is dental amalgam Trituration?
- 3 What is the setting time of amalgam?
- 4 Why is amalgam polished after 24 hours?
- 5 What is eta phase in amalgam?
- 6 How is amalgam used in dentistry?
- 7 What is the history of amalgam amalgam dentistry?
- 8 What happens if you are allergic to amalgam fillings?
What is the setting reaction of amalgam?
The setting reaction begins with dissolution of silver and tin into liquid mercury; most of the product phases precipitate in the liquid mercury. The processes that produce supersaturation in the liquid mercury and the subsequent nucleation and growth of solid phases are considered.
How long after amalgam placement should amalgam polishing be performed?
Most amalgam restorations can be polished at least 24 hours after placement. This allows sufficient time for the amalgam to set.
What is dental amalgam Trituration?
Trituration: Definition: refers to the process of mixing together Hg and alloy particles to produce a coherent plastic and homogenous mass of condensable amalgam.
What is gamma 2 phase in amalgam?
The gamma 2 phase involves the binding of tin and mercury (Sn7-Hg). The gamma 2 phase is responsible for early fracture and failure of the comminuted particle amalgam restorations. Tin cannot be eliminated from the alloy because of its importance in the setting reaction and control of dimensional change of amalgam.
What is the setting time of amalgam?
The setting time of amalgam depends on the composition of the alloy, the shape and size of the particle and the mixing time. 90 \% of the final hardness will be reached after 10 – 12 hours.
What is a setting reaction?
The setting reaction of a CPC consists of the dissolution of one or more constituents of the cement powder and the precipitation of a different calcium orthophosphate. Physically, it takes place by the entanglement of the crystals of the precipitating calcium orthophosphate.
Why is amalgam polished after 24 hours?
Improved marginal adaptation and reduced surface tarnish and marginal corrosion are among the purported benefits of finishing and polishing of amalgam restorations. ~ A period of at least 24 hours after insertion generally has been advocated for the finishing and polishing of conventional amalgams.
What is the final step in finishing a composite resin?
Polishing is the final but also vital step in a successful anterior composite restoration.
What is eta phase in amalgam?
Although eta’ is more resistant to corrosion than gamma 2(Sn-Hg) which appears in low-copper amalgams, it is the least corrosion resistant major phase in high-copper amalgams and can suffer deterioration.
What is the formula of amalgam?
Amalgam Mineral Data
| General Amalgam Information | |
|---|---|
| Chemical Formula: | Ag2Hg3 |
| 100.00 \% | |
| Empirical Formula: | Ag2Hg3 |
| Environment: | Base metal ore deposits with oxidisable mercury sulfides. |
How is amalgam used in dentistry?
Dental amalgam is a dental filling material used to fill cavities caused by tooth decay. Dental amalgam is a mixture of metals, consisting of liquid (elemental) mercury and a powdered alloy composed of silver, tin, and copper. Approximately half (50\%) of dental amalgam is elemental mercury by weight.
What is the setting reaction of alginate?
Setting reaction: Primary reaction: 2Na3PO4 + 3CaSO4 -> Ca3 (PO4)2 + 3Na2 SO4. Reaction with Retarders to increase the setting time: Na Alginate + 3 CaSO4 -> Ca Alginate + 3Na2SO4.
What is the history of amalgam amalgam dentistry?
Dental amalgam was developed in France in the 1800s. It was introduced to the United States in 1833, and the mercury toxicity controversy started immediately. This controversy divided U.S. dentists into pro-amalgam and anti-amalgam groups. At that time, the only alternatives for direct restorative materials were direct gold and dental cements.
How long does amalgam need to be supported?
Therefore, amalgam should be supported by tooth structure for clinical success in the long term, which is approximately 10 to 20 years. Also, amalgam needs sufficient bulk. A thickness of 1.5 mm or more is needed to withstand occlusal forces.
What happens if you are allergic to amalgam fillings?
Dental amalgam might cause these individuals to develop oral lesions or other sensitivity reactions. If you are allergic or otherwise sensitive to any of the metals in dental amalgam, you should not get amalgam fillings. You can discuss other treatment options with your dentist. Why is mercury used in dental amalgam?
Are amalgams a good predictor of future tooth decay?
Clinical research has shown that marginal integrity of dental amalgams is a poor predictor of recurrent decay. Amalgam is the least technique-sensitive permanent restorative material that is available to the dentist.