Sir, Messrs Foley, Evans and Blackwell (BDJ 2004, 197: 697) have given me great pleasure in their study of the restoration of deciduous molars – especially in their use of Black Copper Cement (BCC). In Manchester in 1950 we had studied a variety of topical methods to prevent dental caries – I must say without success1.

We found that BCC was an excellent fissure sealant for first permanent molars but which required renewal every six months. We did not publish these results on account of the temporary nature of the sealant. We did not use it for restoring deciduous molars as the acid from the BCC caused pulpal irritation. We later discovered the multiplicity of root canals in deciduous molars which could convey the acid to the pulp2.

As students we had been taught to line all cavitities before using silicate restoration on account of the free acid – later we found the reason – the possible presence of 'giant tubules'3.

I have not been surprised that in the Dundee study some pulpal problems occurred. BCC (Ames) was a blessing for first permanent molars in the days before modern sealants.