With the exception of wisdom teeth, we at Blue Raven Dental believe that a lost tooth should be replaced soon after and that there should be no gaps in the mouth. We also believe that the most ideal tooth replacement is by means of a ceramic (porcelain) crown, held securely by a dental implant (which is an artificial tooth root).
Historically, other options would have been to use teeth next to a gap to hold a "bridge" - we don't do this as it damages the holding teeth, or by making a partial denture ( "plate"; "false teeth") - we don't do this because it damages gums and teeth. Furthermore, we no longer make Full dentures (i.e. replacing all the teeth) unless they are to be anchored securely with dental implants.