NATIONAL INSTITUTE OF CLINICAL EXCELLENCE in March 2008 has given  new recommendations for dental/oral surgery done to patients having structural heart conditions.

They have recommended:

- that antibiotics are no longer needed for IE in patients undergoing dental , GI  and other minor procedures as the risks of allergy and emergence of resistant strain are much higher than the  benefits ( if any) to be justified.

- that the patients must be warned against a small risk of IE incase such a thing happens. And of course they must be told about the ways to recognise symptoms of IE beforehand so that they can look out for them.

- and that the patients must have their oral hygiene impeccable before any procedure being done in these cases. 

You can look into the full details of the current stand in NICE GUIDELINE 64.

Acknowledgements: National Institute of Clinical Excelence (UK)