Effect of demineralization on stainability of human mast cells in normal periodontal membranes, apical granulomas and radicular cysts

abstract — The material comprised normal human periodontal membranes, apical granulomas and radicular cysts attached to extracted teeth. Chronically inflamed human gingiva and different rat tissues served as controls. The following demineralizing agents were tested: 5.3% HNO₃, 2% formic acid +20% Na-citrate, 5% EDTA, 10% EDTA+7.5% PVP, 0.05 M EDTA+0.22 M sucrose. Fixation: 4% aqueous solution of basic lead acetate with formalin 1:10 added. The following staining procedures were applied: toluidine blue pH 4.0, astra blue pH 0.2–0.3, naphthol-esterase-GBC pH 7.4, and acridine orange in 5% ALSO₄, pH 3.4. Demineralization in HNO₃, formic acid+Na-citrate, and 5% EDTA proved unsatisfactory. EDTA+PVP showed valuable staining results, but no secondary fluorescence could be observed after 18 d of exposure to this fluid. The best results were obtained with EDTA+sucrose. Even after 120 d of exposure to this demineralizing agent the human mast cells could be readily demonstrated by all four staining techniques used. In addition, the human mast cells appeared morphologically well preserved.