Abstract

Background: Studies in the dental literature and guidelines from the American Dental Association (ADA) and American College of Chest Physicians (ACCP) suggest that oral anticoagulants do not need to be discontinued prior to dental extraction. Despite this, anticoagulants are routinely discontinued due to perceived risks in bleeding. This practice may place patients at avoidable risk of thromboembolic complications.

Objectives: To compare how oral surgeons and hematologists manage patients receiving long-term vitamin K antagonists (warfarin) who also require dental extraction.

Design: Cross-sectional survey.

Methods: Pre-tested surveys were mailed to 168 oral and maxillofacial surgeons and 123 hematologists/thromboembolism specialists licensed to practice in Ontario, Canada. The survey consisted of 3 parts: an assessment of bleeding and thrombotic risk factors that influence practioners’ decision to discontinue anticoagulants, individual scenarios assessing practice patterns, and clinical scenarios with varying risks of bleeding and thrombosis. For the clinical scenarios, respondents were asked to rate their risk perception on a 10-point scale, and the means and standard deviations of the responses between oral surgeons and hematologists were compared using unpaired t-tests, SPSS Version 12.0.

Results: A total of 291 surveys were mailed with a response rate of 47% (136 surveys). 82 (60%) of the respondents were oral surgeons (75% community-based, 25% academic) and 54 (40%) were hematologists (28% community-based, 72% academic). Warfarin is routinely discontinued at least 50% of the time by 37% of dental surgeons, compared to 71% of hematologists; 29% of hematologists reported always discontinuing warfarin. The 3 main factors that influence oral surgeons’ and hematologists’ decision to discontinue warfarin are complicated procedures, multiple extractions and patients with a prior history of bleeding; 20% of hematologists discontinue anticoagulants because of specific referral to manage anticoagulants around the time of extraction. The maximum international normalized ratio (INR) that hematologists consider acceptable for extraction is 2.0, with no hematologists recommending extraction above this level; 86% of oral surgeons would proceed with extraction with an INR up to 3.0. In the individual scenarios, oral surgeons are more likely to continue warfarin and use local measures (sutures, gelfoam) to control bleeding. Hematologists are more likely to discontinue warfarin, use bridging anticoagulant therapy and recommend antifibrinolytic agents. In the clinical scenarios assessing thrombotic risk, oral surgeons are more likely to perceive that the risk of thrombosis is higher than hematologists (p < 0.01). In contrast, in the clinical scenarios assessing bleeding risk, the risk of bleeding was rated to be similar by both groups.

Conclusions: Despite ADA and ACCP recommendations to continue anticoagulant therapy in most patients undergoing dental procedures, over 70% of hematologists, and 37% of dental surgeons in our survey frequently discontinue anticoagulants. Although the cited reasons for discontinuation are similar between the 2 groups, the frequency of discontinuation is significantly lower in oral surgeons and may be related to the perception that thromboembolic risks are high compared to hematologists’ risk assessments.

Disclosure: No relevant conflicts of interest to declare.

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