Sir, we would like to respond to the recent request from P. Woodhouse for advice about antibiotic cover (Left out to dry BDJ 2006; 201: 741). The BDA advises members to follow guidance given in the BNF when considering antibiotic prophylaxis for patients with joint replacements, drug/radiation induced immunosuppression or conditions like systemic lupus erythematosus. BNF 52 (Section 5.1 Antibacterial drugs - Table 2. Summary of antibacterial prophylaxis) states that 'patients with prosthetic joint implants (including total hip replacements) do not require antibiotic prophylaxis for dental treatment' and that 'patients who are immunosuppressed (including transplant patients) and patients with indwelling intraperitoneal catheters do not require antibiotic prophylaxis for dental treatment provided there is no other indication for prophylaxis'. Patients with systemic lupus erythematosus who do not have endocardial disease do not routinely need antibiotic prophylaxis. From a dento-legal perspective, Dental Protection recognises that clinicians face an unsatisfactory period of uncertainty where different guidelines exist simultaneously. It advises that dentists should be aware of the debate and keep abreast of developments to ensure that appropriate guidance is followed.