<prompt> In a child with a pre-existing cardio valvular disease, antibiotic prophylaxis should be administered before a dental extraction so as to prevent:Bacterial endocarditisCongestive cardiac failurePneumoniaRheumatic carditis  <response>: Premedication with a systemic backgroundPatients with Subacute Bacterial Endocarditis - antibiotic prophylaxis is needed.Patients with abscess - antibiotic therapy.In a child with a pre-existing cardio valvular disease, antibiotic prophylaxis should be administered before a dental extraction so as to prevent bacterial endocarditis.Reference: Pediatric Dentistry SECOND EDITION, Shobha Tandon; page no 163 