Oral anticoagulant therapy is widely used in the prevention and treatment of thrombotic complications. Atrial fibrillation, prosthetic heart valves, deep-vein thrombosis, and pulmonary embolism are the most common indications for long-term or lifelong use of oral anticoagulants (Guyatt et al., 2012). Vitamin K antagonists (VKA), acting as inhibitors of vitamin K epoxide reductase — an enzyme necessary for the synthesis of biologically active vitamin K-dependent coagulation factors (II, VII, IX, and X) — have been the dominant therapeutic approach in named indications for decades (Ageno et al., 2012).

Due to the narrow therapeutic range of VKAs, numerous food and drug interactions, and individual responses to treatment, close monitoring of their effects is necessary. The International Normalized Ratio (INR) is used for monitoring the anticoagulant effect of VKA. An INR range of between 2.0 and 3.0 is optimal in most indications. For patients with a high risk of thromboembolism, such as those with a mechanical mitral valve, higher INR values of up to 3.5 are recommended (Guyatt et al., 2012).

Recently, new oral anticoagulant drugs, referred to as direct oral anticoagulants (DOAC), have become available for clinical use. Dabigatran is a reversible competitive thrombin inhibitor. It inhibits free and clot-bound thrombin. Rivaroxaban, apixaban, and edoxaban are reversible inhibitors of factor Xa that catalyze the conversion of prothrombin into thrombin. DOACs are mostly indicated in patients with nonvalvular atrial fibrillation for the prevention of stroke and systemic embolisms, as well as the prevention and treatment of venous thrombosis (Ageno et al., 2012; Siegal and Crowther, 2013).

DOACs have certain advantages compared with VKA. These drugs have a rapid onset of action and a predictable anticoagulant effect that does not require routine monitoring. Furthermore, DOACs have a wide therapeutic index and limited drug and food interactions (Ageno et al., 2012; Little, 2012; Firriolo and Hupp, 2012). Considering all these factors, it is likely that DOACs will be increasingly used in the future.

There is a large amount of evidence that local hemostatic measures are sufficient to prevent bleeding after minor oral surgical procedures in patients taking VKAs without therapy interruption if INR is within therapeutic levels (INR ≤4.0) (Wahl et al., 2015; Rocha et al., 2019). The most commonly used local hemostatic agents are: oxidized cellulose, resorbable gelatin sponges or collagen sponges, fibrin glue, cyanoacrylate glue, platelet-rich plasma gel, or antifibrinolytics applied directly into the wound or in the form of a solution as a mouthwash (de Abreu de Vasconcellos et al., 2023). None of the local hemostatic agents has been shown to be superior to the others (Moreno-Drada et al., 2021).

Similar recommendations, mainly based on experts’ opinions, have been made for the dental treatment of patients taking DOACs (Little, 2012; Firriolo and Hupp, 2012; van Diermen et al., 2013; Mauprivez et al., 2016). However, many controversies regarding dentoalveolar surgical procedures in these patients remain. Two recent surveys conducted in Europe (Precht et al., 2019) and Australia (Foo et al., 2021) have shown that there is no consensus among dentists and oral and maxillofacial surgeons regarding the dental treatment of patients taking DOACs.

Our study was conducted to evaluate whether DOAC or VKA therapy within the therapeutic range (INR level 2.0–3.5) increases the risk of postoperative bleeding after dentoalveolar surgery.