Sir, I write further to my letter published earlier in the year (BDJ 2008; 204: 477) and A. Milne's reply (BDJ 2008; 205: 615).

Having started the debate in 19811 I have had the benefit of reviewing the literature2,3 as it has developed, without bias and with consistent regard for scientific principles and protocols. Hand-picking studies that have aberrant or inconclusive results when weighed against the accepted evidence becomes self-serving while simultaneously destructive to clinicians seeking the best for their patient.4 As recently as March 20085 research has shown that formocresol causes genetic damage. Studies using the comet assay have previously produced contrary results when examining peripheral lymphocytes.6

Some studies dismiss the addition of cresol without scouring the literature. I am baffled when I read: 'No data currently exist regarding ... environmental sources of cresol' and its inclusion in formocresol is dismissed as unimportant.7 Cresol exposure runs the gamut from photographic materials to cigarette smoke and various forms of cresol have been identified as being mutagenic from the early 1980s onward. Newer research shows its genotoxicity to mammalian cells.8

I urge dentists to rethink their use of formocresol. Children should not be exposed to formocresol since there isn't any conclusive evidence warranting its use.