A. 16 is a little a young the best treatment at the moment would be a simple denture or a non prepping Maryland bridge so the adjacent teeth are not damaged.  You can even try a Rochette style bridge as they are quite retentive.  When was the tooth removed ? Was there a lot of damage to the bone??  If so it might be worth looking at the need for bone grafting now of even connective tissue graft so in about 9-12 months an implant can be placed.