Severe bone loss is associated with the tooth #9 (Fig.2).  There is calculus over the curved root (<).  The access is filled with composite, suggesting root canal therapy has been tried without success.

A 4.5x14 mm bone-level implant appears to be a proper root replacement (Fig.3).

Tough Case

Xin Wei, DDS, PhD, MS 1st edition 02/26/2015, last revision 01/19/2018