[Effect of caffeine or NaCl on wound healing of the rat gingiva. Light and electron microscopic studies]

The present study was carried out to investigate histological and ultrastructural changes, particularly changes of the epithelium-connective tissue junction, in rat gingival wounds treated with Caffeine or NaCl. Light Microscopy The animal had an incision in the lingual gingiva of lower incisors. Immediately after incision, the wounds of Groups A, B and C were treated with distilled water, caffeine (2.5%) and NaCl (25%), respectively. The gingivae were examined histologically at 1, 2, 4, 6, 8, 12 and 28 days after treatment. Electron Microscopy Groups a, b and c received the same treatment as those of Groups A, B and C, respectively. The gingivae were examined ultrastructurally at 4 and 28 days after treatment. 1. Light Microscopic Observations (1) Group A. On all experimental days, the wounds were covered by the epithelium. At 1 and 2 days, the connective tissues exhibited depositions of fibrin, but, at 4, 6 and 8 days, they showed the granulation tissues. At 12 and 28 days, the connective tissues appeared normal. (2) Group B. On all experimental days, the wounds were covered by the epithelium. At 1 and 2 days, the connective tissues exhibited depositions of fibrin. At 4, 6 and 8 days, they displayed granulation tissues. At 12 and 28 days, the connective tissues appeared normal. (3) Group C. On all experimental days, the wounds were covered by the epithelium. At 1 and 2 days, the connective tissues exhibited depositions of fibrin. At 4, 6, 8 and 12 days, they displayed granulation tissues. At 28 days, the connective tissue was normal. (4) Histometrically, at 6 days, Groups A, B and C exhibited the highest, intermediate and lowest number of fibroblasts per unit area, respectively. There were no differences in the number of inflammatory cells between all three groups. 2. Electron Microscopic Observations (1) Group a. At 4 days, the normally-formed gingival basal lamina was observed rather frequently just beneath the basal surfaces of basal cells. On occasions, the basal lamina exhibited various changes such as detachments, breaks, thickenings and duplications. Moreover, absence of the basal lamina was observed. At 28 days, the irregular types of basal laminae decreased in number, and most of the basal laminae appeared normal in structure. (2) Group b. At 4 days, the normally-formed gingival basal lamina was observed less frequently as compared with those of Group a. The above-mentioned various changes of the basal lamina were found rather frequently.(ABSTRACT TRUNCATED AT 400 WORDS)