Clinical analyses
postoperative pain, defect tightness
The patients were regularly and prospectively followed up with recalls on the postoperative days 7 and 21. Additional recall visits were scheduled, if any clinical problems were encountered. All follow-up visits comprised evaluation of the clinical healing outcome such as defect tightness (primary outcome measurement) for the defect closure of oroantral communication using PRF (test group) or buccal advancement flap (BAF; control group). Secondary outcome measurements included -1) evaluation and comparison of patient-related, surgery-related or anatomical risk factors affecting the wound healing process for OAC treated with PRF or BAF, -2) comparison of the wound healing course between PRF and BAF using a scoring system with defined healing indices, -3) evaluation of the displacement of mucogingival line as well as -4) evaluation of postoperative pain and of the use of painkillers.