Oops - just realised the rest of the ISIS article is as interesting as the bit I posted! Here's the rest (from here - www.isisonline.org.uk/sleep_health/sleep_aids/dummies/ )
In some of the SIDS studies it was only babies who didn’t have a dummy – but normally used one – that were more vulnerable. Those babies who never had a dummy were not at higher risk, which suggests that if you start giving your baby a dummy for sleep then you must always give it.
Studies have shown that dummy use can have unwanted effects. Some have found that dummy use can lead to less breastfeeding and earlier weaning from the breast. An up-to-date review of research found dummies did not cause mothers to stop breastfeeding earlier (up to when their babies were 4 months old) when were very motivated, or keen, to breastfeed. However they were not able to say whether or not less motivated mothers might be disadvantaged by dummy use. Breastfeeding in itself reduces the risk of SIDS, along with other diseases, and helps with mother-baby bonding.
Links have also been found between dummy use and tummy and chest infections? and recurrent infections of the middle-ear.
For these reasons, along with the lack of information we have about how dummies work to reduce SIDS, and in which groups of babies they might have most effect, the UK Department of Health does not currently recommend dummy use as a way of reducing the risk of SIDS, however some cot death prevention organisations do.