The investigators planed to observe the microbiome of an aggressive periodontitis patient, during mechanical treatment, surgery(if indicated) and implant placement. The investigators designed to observe the changes after mechanical treatment.Then, the investigators will compare the sub-mucosa microbiome of implant and the subgingival community. The investigators expected a different community after treatment, and there could be similarity between implant and nature teeth.

Inclusion Criteria:

1. Subjects were between 18-35 years old and diagnosed with generalized aggressive periodontitis (GAgP) according to the 1999 International Classification of Periodontal Diseases (Armitage 1999);
2. At least 20 teeth in the first appointment and at least 3 teeth(other than first molars and central incisors)with a probing depth(PD) ≥ 6mm, clinical attachment level (CAL)≥5mm;
3. The clinical diagnosis was confirmed by evidence of inter-proximal bone loss on full-mouth periapical radiographs;
4. Family history of aggressive periodontitis.

Exclusion Criteria:

1. Uncontrolled systemic conditions including diabetes and hypertension;
2. Pregnant or lactating;
3. Smoking;
4. Received periodontal treatment within the previous 6 months or antibiotic medication during the previous 3 months.

aggressive periodontitis patients with defection of dentition or shall extracted hopeless teeth, and intended to implant treatment.

haven't decided yet