CDA Essentials 2017 • Volume 3 • Issue 4

36 | Volume 3 Issue 4 S upporting Y our P ractice Two studies investigated the effect of tranexamic mouthwash after tooth extraction. The first one 20 randomly assigned patients to a 5- or a 2-day regimen of 4.8% tranexamic acid mouthwash applied 4 times a day. Minor bleeding was observed in only 3 patients and there were no significant differences between the groups. The second study 21 compared a 7-day regimen of 4.8% tranexamic acid mouthwash with autologous fibrin glue that was applied to the extraction sockets and over the sutures. Minor bleeds were observed in only 2 patients in the autologous fibrin glue group, with no significant differences among the groups. Both studies concluded that the compared interventions were similarly effective. Finally, a study 23 compared the effectiveness of the fibrin adhesive Beriplast P (CSL Behring, King of Prussia, Penn.), with the resorbable oxycellulose dressing Surgicel (Johnson & Johnson, New Brunswick, N.J.). After dental extraction, sockets were dressed with 1 of the hemostatic agents and sutured with softgut. Bleeding was observed in 3 patients in total: 2 required additional suturing and 1 required admission to hospital because of more significant bleeding. The low bleeding rate did not allow statistical testing of the difference. The authors concluded that both treatments were equally effective in preventing bleeding after dental extractions. Warfarin Continuation vs. Discontinuation One study 22 randomly assigned patients to continue or discontinue warfarin 2 days before dental extraction. The authors reported a higher rate of bleeding in patients who continued warfarin (26%) than in those who stopped (14%), although the difference was neither statistically nor clinically significant. Two patients in the warfarin continuation group required a hospital visit to stop the bleeding. The authors concluded that warfarin can be safely continued in patients who undergo dental extraction in a hospital setting if their INR is below 4.1. The other study 17 applied a factorial design of 4 possible combinations of warfarin continuation and discontinuation and suturing and no suturing. The observed bleeding rate on the first postoperative day was slightly but not significantly higher in the 2 groups that continued warfarin compared with the groups that discontinued warfarin treatment. Bleeding rates significantly diminished by day 7 with no significant differences among the groups on any of the postoperative days. Suturing did not play any role, and wound healing was similar across the groups. All bleeding events were described as “of the mild transient type.” 17 The authors concluded that warfarin therapy can be safely continued in patients during dental extractions if the INR is 3 or lower; however, suturing or any other invasive manipulation should be used only when required. 17 Discussion Although these studies rated highly in terms of quality of evidence, some risks of potential bias were identified—the most significant one being the lack of blinding. The role of patient blinding was crucial in these studies as bleeding was first reported by patients and then reviewed by treating doctors, if necessary. Only 1 study reported blinding of outcome assessors, 17 and 1 reported partial blinding of personnel. 19 Inadequate blinding in the included studies may have introduced reporting and measurement biases. Regular INR monitoring is part of the standard care for patients taking warfarin. 26 All 6 studies included the requirement for an INR within therapeutic range, and INR was actively monitored postoperatively. Therefore, the findings are applicable only to patients whose INR is within the therapeutic range before dental extraction. This is in agreement with past clinical care pathways in oral surgery that have recommended measuring INR before the intervention and making a decision about continuation or discontinuation of the anticoagulant or the use of bridging therapy only afterwards. 2,8 The average number of dental extractions per patient varied from 1.5 to 6.5, a significant range, especially considering the potential associated risks of surgical intervention and post-surgical complications. However, past studies have not found an association between risk of bleeding and number of extracted teeth among patients on antithrombotic therapy. 27,28 Studies included in the review also varied in type of extractions. The availability and applicability of the hemostatic agents in Canada must further be considered. For example, Beriplast P is not available in Canada and tranexamic acid mouthwash is not readily available, is relatively expensive and largely relies on patient compliance as multiple mouth rinses are required. The fabrication of autologous fibrin glue involves the acquisition of the patient’s blood 1–2 weeks in advance, 21 limiting its practicality. Histoacryl glue is only effective for wounds in which the edges can be approximated, its use is technique sensitive and it may pose an occupational hazard for dental staff. 29 Surgicel, in comparison, is more widely available, is easier to administer and is less costly. No study compared the use of hemostatic agents (while continuing warfarin) with warfarin