“…Investigations conducted in our laboratory indicate that pulpal inflammation in experimenul cavities filled with glass ionomer luting, base and restorative materials is related to Correspondence: Dr R. S. Tobias, Department of Oral Pathology, University of Birmingham Dental School, St Chad's Quemsway, Birmingham B4 6NN,UK. the amount of microbial microleakage at tbe interface of cavity wall and material (Browne et al 1983, Plant et al 1984, Tobias et al 1989). However, some workers beiieve that such microbial microleakage does not accotint for the post-cementadon sensitivity associated with glass ionomer ludng cements (Fitzgerald et al 1987, Heys et al 1987, but that premature moisture contamination of the glass ionomer before the setting reaction is complete tnay allow fluids to contact the cut dentine surfaces, thus causing sensitivity.…”