Sir, I was interested to read the paper on minimal intervention dentistry by Ngo and Opsahl-Vital (BDJ 2014; 216: 561–565). The article states that glass ionomers were introduced to the dental profession in 1988. I believe it was much earlier. I still have my 'ticket book' given to all students at Guy's and in which all restorations and materials were recorded. In it I see that on 6.10.1977 as a third year student I did a restoration with ASPA – alumino silicate polyacrylic acid. I believe this was the first commercial GIC material, made by De Trey. On the ticket the demonstrator has noted that underneath it was my first pulp exposure. A cutting edge day for me in several respects.

1. Dunedin, New Zealand