Amalgam fillings seem safe for children in the short term

Dental amalgam is half mercury, a well known neurotoxin. A vigorous debate has run for years about whether amalgam fillings poison children, mostly without the benefit of decent prospective evidence. The first two randomised trials to consider this indicate that amalgam is safe, at least in the short term. Both studies failed to find any indication of neurological damage in children whose back teeth were filled with amalgam. Controls had their back teeth filled with a resin composite instead. The trials were relatively small, however, given that many millions of children worldwide have amalgam fillings, and a linked editorial remains somewhat sceptical (pp 1835-6). Neither trial was powerful enough to detect subtle neuropsychological changes in children given amalgam fillings. Even if these changes occurred with an incidence of only 1%, they would still affect about 500 000 children worldwide. In both trials, children treated with amalgam had significantly higher urinary concentrations of mercury than children treated with composite resin. They were followed up for seven years or less, so longer term effects cannot be ruled out. The editorial concludes that it's too early to end the debate (or the research) on the safety of amalgam fillings for children.

Rare but lethal complication follows ablation procedure for atrial fibrillation

Radiofrequency ablation around the pulmonary vein is an effective treatment for some patients with atrial fibrillation. Most of the time it's safe. But reports are emerging of a rare and catastrophic complication—the formation of a fistula between the oesophagus and the left atrium. Twelve cases have been reported, and only one patient has survived.

The most recent case series included nine patients who presented between 10 and 16 days after their ablation procedure. They had non-specific symptoms at first; most had a fever and felt generally unwell. All nine developed septicaemia, eight developed neurological symptoms characteristic of cerebral air embolism …