Recommendation grades (A-C) and levels of evidence (Ia-IV) are defined at the end of the "Major Recommendations" field.
- The risk of significant bleeding in patients on oral anticoagulants and with a stable international normalised ratio (INR) in the therapeutic range 2-4 (i.e., <4) is very small and the risk of thrombosis may be increased in patients in whom oral anticoagulants are temporarily discontinued. Oral anticoagulants should not be discontinued in the majority of patients requiring out-patient dental surgery including dental extraction (Grade A Level Ib).
- Recommendations: For patients stably anticoagulated on warfarin (INR 2-4) and who are prescribed a single dose of antibiotics as prophylaxis against endocarditis, there is no necessity to alter their anticoagulant regimen (Grade C, Level IV).
- The risk of bleeding may be minimised by:
- The use of oxidised cellulose (Surgicel) or collagen sponges and sutures (Grade B, Level IIb).
- 5% tranexamic acid mouthwashes used four times a day for 2 days (Grade A, Level Ib). Tranexamic acid is not readily available in most primary care dental practices.
- For patients who are stably anticoagulated on warfarin, a check INR is recommended 72 hours prior to dental surgery (Grade A, Level Ib)
- Patients taking warfarin should not be prescribed non-selective non-steroidal anti-inflammatory drugs (NSAIDs) and cyclo oxygenase-2 (COX-2) inhibitors as analgesia following dental surgery (Grade B, Level III).
Definitions:
Classification of Evidence Levels
Ia Evidence obtained from meta-analysis of randomised controlled trials.
Ib Evidence obtained from at least one randomised controlled trial.
IIa Evidence obtained from at least one well-designed controlled study without randomisation.
IIb Evidence obtained from at least one other type of well-designed quasi-experimental study (a situation in which implementation of an intervention is without the control of the investigators, but an opportunity exists to evaluate its effect).
III Evidence obtained from well-designed non-experimental descriptive studies, such as comparative studies, correlation studies and case studies.
IV Evidence obtained from expert committee reports or opinions and/or clinical experiences of respected authorities.
Classification of Grades of Recommendations
Grade A - Requires at least one randomised controlled trial as part of a body of literature of overall good quality and consistency addressing specific recommendation. (Evidence levels Ia, Ib).
Grade B - Requires the availability of well conducted clinical studies but no randomised clinical trials on the topic of recommendation. (Evidence levels IIa, IIb, III).
Grade C - Requires evidence obtained from expert committee reports or opinions and/or clinical experiences of respected authorities. Indicates an absence of directly applicable clinical studies of good quality. (Evidence level IV).
