Ultrastructure of initial calcification on exposed human pulp applied with autogenous dentin fragments

Initial calcification in human dental pulp has been studied with electron microscopy in 20 human teeth over a period of 21 days following pulp exposure and capping with autogenous dentin fragments. Five days after operation, dentin fragments were surrounded by degeneration cells and inflammatory cells. Occasionally a macrophage that had phagocytosed a dentin fragments was observed. Fourteen days after operation, osmiophilic needle-like crystalline structures were found in spherical bodies in the collagen fibrils or on the dentin surface. Ca and P were detected in these needle-like crystalline structures by energy dispersive X-ray analysis. They tended to increase in size and to fuse together to form mineralizing globules with the passage of time. Initial calcification around the dentin fragments developed various patterns, including spherical bodies in the collagen fibrils and direct apposition of needle-like crystals on the dentin fragments.     

Ultrasonic evaluation of cervical lymph node metastasis of squamous cell carcinoma in oral cavity

Forty-four patients with oral cancer were examined by ultrasonography to detect cervical lymph nodal metastases. The lymph nodes, which were histopathologically or clinically confirmed to have cancer metastases, showed the following characteristic echogram findings: distinctive nodal boundary, posterior echo enhancement and an increased ratio of the shortest and the longest diameters of the node. It is suggested that these three peculiar ultrasonographic findings are considered to be important items for the differential diagnosis of benign nodes from the cervical metastasis of oral cancer.     

The presence of bacteria in the oral epithelium in periodontal disease. III. Correlation with Langerhans cells

Langerhans cells (LC) are cell types found in the skin and gingiva. LC have immunological functions as phagocytic cells and as antigen-presenting cells for T and B lymphocytes. Sections from biopsies of the gingiva in cases of periodontal disease were found to have increased numbers of LC. These biopsies also contained intragingival bacteria. Serial sections of frozen specimens of human gingiva were prepared for staining. Hematoxylin and eosin were used for tissue survey, the Gram stain for assessment of bacterial invasion, anti-Leu-6 monoclonal antibody associated with peroxidase technique (PAP) to identify LC, antibacterial sera to Bacteroides gingivalis and Actinobacillus actinomycetemcomitans associated with peroxidase to specifically identify these two common periodontopathogenic bacteria. Additional positive identification of bacteria was performed by preparing the same histological section containing gram-stained particles for scanning electron microscope and transmission electron microscope LC confirmation. The results suggest that the increased number of LC seen in diseased sites of oral epithelium containing intragingival microorganisms may be one of the host immune mechanisms to penetration by bacteria.     

Calcitonin gene related peptide: a sensory transmitter in dental pulps?

Nerve fibers displaying calcitonin gene related peptide (CGRP) immunoreactivity occurred in dental pulps of several mammals, including man. The CGRP fibers were more numerous in the apical parts than in the coronal parts and were distributed around small blood vessels as well as in the pulpal stroma without any obvious relation to blood vessels. The trigeminal, spinal and jugular-nodose ganglia harbored a moderate supply of CGRP immunoreactive perikarya and nerve fibers. Immunocytochemic double staining revealed the coexistence of CGRP and SP in a population of perikarya in the sensory ganglia and suggested coexistence of the two peptides in perivascular nerve fibers in the cat dental pulp. The cervical sympathetic ganglia did not contain CGRP-immunoreactive perikarya. Cervical sympathectomy (studied in the guinea-pig and rat) did not affect the frequency or distribution of pulpal CGRP fibers. The distribution of CGRP fibers within the dental pulp and the presence of CGRP perikarya in sensory ganglia known to supply the dental pulps indicate that the pulpal CGRP fibers are sensory in nature and that CGRP together with SP may participate in the regulation of local blood flow and the response to local inflammation.