It has long been a standard procedure to replace coumarin by heparin if a patient using this oral anticoagulant had to undergo dental surgery. The Quick-Value had then to exceed a certain limit before surgery could be safely performed. Today this procedure has changed in that a switch to heparin is only made for invasive and large area surgery. Simple dental extractions, small biopsies and periodontal treatments are performed under continuous oral anticoagulation and local hemostyptic measures are applied. It has been shown that the likelihood of postoperative bleeding complications after adequate local hemostasis during dental surgery is much lower than is the risk of thrombosis or embolic complication following cessation of anticoagulant medication before surgery.