Penetration of the pulp chamber by carbamide peroxide bleaching agents.

Hydrogen peroxide readily penetrates the pulp chamber of freshly extracted teeth. This study was undertaken to determine whether carbamide peroxide also penetrates the pulp chamber. Freshly extracted teeth were sectioned 2 to 3 mm apical to the cementoenamel junction and the coronal pulpal tissue was removed. Acetate buffer was placed in the pulp chamber to absorb and stabilize any peroxide that might penetrate. The coronal portion of each tooth was immersed in either carbamide peroxide gel or gelled hydrogen peroxide at various concentrations for 15 min at 37 degrees C. The buffer was removed, leukocrystal violet was added, and the optical density of the resulting blue solution was determined spectrophotometrically. Amounts of peroxide found in the pulp chamber after 15 min ranged from 3.3 +/- 0.38 micrograms for the 10% sample to 40.4 +/- 3.51 micrograms for the 30% sample.

Ulcerated lesion of the alveolar ridge.

Histoplasmosis is a generalized fungal infection that is caused by the organism H capsulatum. In the most common disease-producing mechanism, the organism is inhaled and lodges in the lung, where it initiates an inflammatory focus. The peribronchial lymph nodes are subsequently involved, forming a primary complex that may ultimately calcify and become radiographically evident. From the primary complex, dissemination by the bloodstream may lead to colonization elsewhere. In the less frequent disease-producing complex, the organism is introduced directly into the tissue through a break in its continuity. A primary complex is then formed by involvement of the lymph nodes. Dissemination from such a focus is rare. It is generally believed that oral and pharyngeal lesions of the histoplasmosis represent symptoms of a systemic disease and are not a localized form of the disease. Histoplasmosis can occur at all ages; however, it is more often found in infancy and old age, especially in white males. Any area in the oral cavity may be affected; the most common sites are: larynx, tongue, palate, buccal mucosa. gingiva, and pharynx. The most frequently reported symptoms are pain, hoarseness, loss of weight, ulcer, and sore throat. The appearance of the oral and pharyngeal lesions may vary and may manifest as ulcers, nodules, or verrucous plaques. Deep, indurated ulcers are common, accounting for the predominant clinical impression of squamous carcinoma.