Patients in the control group will follow the conventional treatment protocol combined with connective tissue graft. Briefly, hopeless tooth will be extracted atraumatically. Implant will be placed in the palatal side and grafting materials will be filled in the buccal gap. Then, connective tissue graft will be harvest from palatal and fixed between bucall mocosa and bucall bone. Healing abutment will placed and collegan sponge will be used to seal the wound. After 4 months, implant impression and crown delivery will be finished.

Patients in the test group will receive conventional immediate implant placement combined with socket shield technique. Briefly, the hopeless teeth will be splited from mesial and distal, the buccal part will be preseved and the palatal part will extracted. Implant will be placed in the palatal side and grafting materials will be filled in the buccal gap. After 4 months, implant impression and crown delivery will be finished.

Connective tissue graft (CTG) is an oral and maxillofacial surgical procedure first described by Alan Edel in 1974. It includes the preparation the recipient site of tissue exhibiting recession by incising the gingival, obtaining the CTG from the donor site, securing the CTG at the recipient site and suturing the incised gingival tissue at both the donor and recipient sites.

An objective index introduced by Furhauser et al. 2005

the mid-buccal mucosal level change from baseline to follow-up

the mesial and dital marginal bone loss from baseline to follow-up evaluated by peri-apical X-ray.