Peri-implantitis Between Periodontitis and Nonperiodontitis Sites With ARP

Inclusion Criteria 1. patients aged ≥ 20 years 2. patients who required tooth extraction and implant therapy 3. at least two bite-wing radiographs: baseline and at least a 6-month follow-up Exclusion Criteria 1. a medical condition as a contraindication to dental surgery, autoimmune disorder, immunosuppression, or uncontrolled diabetes (HbA1c \> 7%); 2. ong-term nonsteroidal anti-inflammatory drug use 3. oral bisphosphonate therapy 4. pregnancy or lactation 5. the absence of follow-up bite-wing radiograph 6. cigarette consumption \>10 per day 7. a history of head and neck radiotherapy.