Despite the benefit of formocresol, there are toxic effects allergic reactions and local soft and hard tissue necrosis have been reported when such formaldehyde compounds were used clinically, however, the adverse effect of the clinically used of this compound are not widely reported. It has been stated that it has a side effect on the permanent successor although it results as a successful technique for the treatment of the primary teeth
4 -9 years old
Primary molars with no spontaneous or provoked pain
Primary molars with at least two-thirds of the root length were still present.
Primary molars with no sign of internal or other kinds of root or bone resorption.
Patients with systemic diseases (congenital or rheumatic heart disease, hepatitis, nephritis, tumor, cyclic neutropenia, leukemia, and children on long-term corticosteroid therapy).
Un-cooperative patients.
Un-restorable primary molars (Grossly broken-down primary molars that have decay extending way under the gingiva and tooth with root caries).