[Experimental allergic pulpitis in rabbits].

Abstract

Ten male, albino rabbits, weighing about 2,5 kg, were sensitized with 0.05% of 1-chloro-2,4-dinitrobenzene (DNCB) in complete Freund's adjuvant. Ten controls received the complete Freund's adjuvant only. Fourteen days later, the animals were submitted to a dental test. The four incisor pulps were exposed under general anesthesia. A sterile cotton pellet with 10-(-4) mg of DNCB was sealed inside the cavity. A skin test was also performed with 0.1% DNCB. The operative trauma was evaluated on five additional control animals. Twenty four hours after the challenge, the animals were killed and their teeth were studied histologically. Three different pulpitis were observed: 1) in animals without DNCB, a traumatic pulpitis with a mild focal necrosis and serous infiltrate; 2) a toxic pulpitis induced by the DNCB in the controls. They were killed and their teeth were studied histologically. Three different kinds of pulpitis induced in sensitized animals. A considerable necrosis is present close to the pulp exposure. This pulpitis is characterized by a marked serous exudate and by an accumulation of lymphocytes, eosinophils and macrophages, either perivascularly or in the pulpal mesenchyme. A modification of the present classification of pulpitis is proposed.