Thirty specimens from10 sets that had cracks in one or more of the three roots were excluded from the results.
The number of specimen with leakage at each level is shown in Table 2. Specimens in calciumhydroxide medicated groups A and B, had the greatest frequency of apical leakage at the 2 mm level, whilst group C, the control group, had greatest frequency at1mmlevel. Calciumhydroxide- medicated groups A and B, were shown to induce significantly more apical leakage than the non-medicated control group C (P < 0.05). However, there was no statistical difference between group A, the EDTA and NaOCl irrigation group; and group B, the NaOCl irrigation group.
Calcium hydroxide-medicated canals had sealer of uneven thickness and non-homogenous appearance whilst non-medicated ones had set sealer of relatively even thickness and homogenous appearance (Fig. 1). Microscopic views showed some cracks and voids in the sealer around the gutta-percha canal filling in the calcium hydroxide-medicated groups.
Table 2. Number of specimens with leakage at each level.
Figure 1. Stereomicroscopic appearances of specimens.
A: a 3-mm level specimen from group A;
a 5-mm level specimen from group B;
a 3-mm level specimen from group C.
Specimens from groups A and B show uneven thickness and non-homogenous appearances of set root-canal cement. Root-canal cement (c) between primary gutta-percha cone (p) and canal wall opposite side of secondary cone (s) appears thicker in calciumhydroxide medicated canals (A, B) than in control (C).