Figure 6 The tooth shown in Figure 5 has been sectioned and this reveals the full extent of the caries. Note that the mesial fissure (right side) is deeply involved with active infected caries some distance into the dentine. Simply sealing this fissure would arrest the caries and, as long as the seal was effective, it would not progress. On the other hand, in the presence of a high caries index, the operator may choose to restore it. The distal fissure would be readily stabilised by a glass-ionomer fissure protection.