Porcelain is fused to an underlying metal structure to provide strength to a filling, crown or bridge. Alloy of gold, copper and other metals resulting in a strong, effective filling, crown or bridge. Alloys of non-noble metals with silver appearance resulting in high strength crowns and bridges.orcelain is fused to an underlying metal structure to provide strength to a filling, crown or bridge. Alloy of gold, copper and other metals resulting in a strong, effective filling, crown or bridge. Alloys of non-noble metals with silver appearance resulting in high strength crowns and bridges.
Limit refers principally to the establishment of a maximum beyond which a person or thing cannot or may not go: The Constitution limits the president's term of office to four years. To restrict is to keep within prescribed limits, as of choice or action: The sale of alcohol is restricted to people who are 21 and older.
noun, plural boundaries. 1. something that indicates bounds or limits; a limiting or bounding line. 2. Also called frontier. Mathematics. the collection of all points of a given set having the property that every neighborhood of each point contains points in the set and in the complement of the set.