The aim of periodontal therapy is resolution of inflammation in the supporting structures of the tooth. Endodontic therapy deals with the disease of the pulp and periapical tissues. Researchers and clinicians have long recognised that an intimate relationship exists between the pulp of a tooth and its surrounding periodontium. The present report describes the use of PRF (platelet-rich fibrin) gel in combination with an intrabony defect and a periapical lesion. The tooth was root canal treated followed by periodontal therapy. A combination of PRF gel, hydroxyapatite graft and guided tissue regeneration (GTR) membrane was used to achieve faster healing of the periapical lesion and intrabony defect. After 1 year, the absence of a periradicular lesion, pain and swelling along with tooth stability and adequate radiographic bone structure indicated a successful outcome. Schlagwörter: guided tissue regeneration, intrabony defect, periodontal-endodontic lesion, periobone-G, platelet-rich fibrin