Since the remaining bone is limited after extraction, it is apparently unsuitable for immediate implant (Fig.2).  Socket preservation seems to be able to gain bone height near gingival margin (Fig.3 red line).  有利因素：窦底皮质骨，薄进入容易，剩余牙槽骨足够取得稳定性。

Bone Height    Last    Next    Next for 提升

Xin Wei, DDS, PhD, MS 1st edition 03/20/2019, last revision 03/27/2021