A 49-year-old man returns for #14 and 15 implant impression.  The tooth #18 is buccally shifted with mobility, which is incompatible with #14 and 15 restoration.  The tooth has to be extracted with socket preservation (Fig.1).  A piece of 6-month collagen membrane is used to cover allograft.

6-Month Last Next Xin Wei, DDS, PhD, MS 1st edition 06/17/2019, last revision 06/18/2019