<P> Removable partial dentures are for patients who are missing some of their teeth on a particular arch . Fixed partial dentures, also known as "crown and bridge" dentures, are made from crowns that are fitted on the remaining teeth . They act as abutments and pontics and are made from materials resembling the missing teeth . Fixed bridges are more expensive than removable appliances but are more stable . </P> <P> Another option in this category is the flexible partial, which takes advantage of innovations in digital technology . Flexible partial fabrication involves only non-invasive procedures . Dentures can be difficult to clean and can affect oral hygiene . </P> <P> Complete dentures are worn by patients who are missing all of the teeth in a single arch--i.e., the maxillary (upper) or mandibular (lower) arch--or, more commonly, in both arches . </P> <P> As early as the 7th century BC, Etruscans in northern Italy made partial dentures out of human or other animal teeth fastened together with gold bands . The Romans had likely borrowed this technique by the 5th century BC . </P>

When was the first set of dentures made