Objectives: To evaluate in vitro fluoride released from conventional glass ionomer cement
(Ketac-Fil Applicap) and compare it to that of nanoionomer (Ketac-N 100) to assess the effect
of different fluoride levels on pulp tissues. The pulp response to both materials was evaluated
in vivo using rats as experimental model in prepared conventional depth and deep cavities,
histologically, immunohistochemically and statistically.
Materials & methods: Two fluoride releasing materials were used in this study; Ketac-Fil
and Ketac-N 100. Fluoride release was evaluated in vitro for each one of them. Class V cavities
with different depths (Group I: conventional depth) and (Group II :deep cavities) were prepared
on the labial surfaces of rat upper incisor. The two main groups were further divided into three
subgroups one left unfilled and the other two according to the type of the filling materials. The
rats were sacrificed after seven days and the teeth were extracted and prepared for microscopic
assessment. The sections were examined histologically with H&E, immunohistochemically
using PCNA and the results were evaluated statistically.
Results: Nanoionomer showed statistically significant higher fluoride release than
conventional glass ionomer cement. Histologically, the pulp response was more pronounced in
prepared cavities filled with Ketac-Fil than those of Ketac-N 100, and the intensity of the pulp
reaction increased as the cavity depth increased. Immunohistochemically, the highest number of
positive PCNA cells was detected in deep cavities filled with Ketac-Fil while the least number
was detected in deep cavities filled with Ketac-N 100.
Conclusion: It was concluded that the initial biocompatibility of Ketac-Fil is much less
than that of Ketac-N 100 and that may be due to rapid setting and higher stability of Ketac-N
100. However, in the present study, the immunohistochemical results revealed that high amount
of fluoride release from Ketac-N 100 had an inhibitory effect on proliferation of the pulp cells.
