Amalgam (dentistry) and other metals may be present in some alloys. This combination of solid particles is known as amalgam alloy. The composition of the alloy particles are controlled by the ISO Standard (ISO 1559) for dental amalgam alloy in order to control properties of set amalgam such as corrosion and setting expansion. It is important to differentiate between dental amalgam and the amalgam alloy that is commercially produced and marketed as small filings, spheroid particles, or a combination of these, suitable for mixing with liquid mercury to produce the dental amalgam. Amalgam is used most commonly for direct, permanent, posterior restorations
Amalgam (dentistry) as pins, slots, holes and grooves can be used for the retention of large amalgam restorations, but they do not reinforce the amalgam or increase its strength. There is no current scientific evidence to justify the extra cost and effort associated with the use of adhesively bonded amalgam restorations in comparison with nonbonded amalgam restorations. In view of the lack of evidence on the additional benefit of adhesively bonding amalgam compared with nonbonded amalgam, it is important that clinicians are mindful of the additional costs that may be incurred. The placement of amalgam restorations can potentially cause sensitivity post-operatively. According