When a tooth is missing, replacement should be considered.  One method is a dental bridge.

Dental bridges utilize adjacent teeth for support.  These teeth are prepared in the same fashion dental crowns are done, and a single unit spans the space.  This unit is cemented or bonded, so there is no worry that one might forget where it was placed (unlike a removable partial denture).

Routine maintenance is important, as decay on supporting teeth can jeopardize the entire bridge.