RESUMEN
The purpose of this study was to determine the role of neutropenia in pulpal inflammation. We investigated the effect of methotrexate-induced neutropenia on pulpal inflammation in rats. Pulpal inflammation was produced by pulpal exposure. Thirty-six rats were divided equally into control and experimental groups. The control animals received no injection, whereas the experimental animals were injected with 7.5 mg/kg of methotrexate once a day for 3 days before the pulpal exposure. The pulp was exposed in the mandibular first molar of all animals, and the exposed areas were left open. Animals were killed at 2, 4, and 7 days thereafter. Before they were killed, peripheral blood was taken. The number of total leukocytes and neutrophils in the peripheral blood of experimental animals was significantly decreased compared with those of control animals. The methotrexate-induced neutropenia resulted in the initiation of a bacterial invasion into the pulpal tissue and an increase in pulpal necrosis, as well as lessened abscess formation. Histometrically, the area of pulpal necrosis in experimental animals was significantly greater than that in the control animals. Immunohistochemically, the neutropenia resulted in inhibition of the infiltration by neutrophils. These results suggest that the neutrophil plays an important role in the defense against bacteria in pulpal tissue.
Asunto(s)
Inmunosupresores/efectos adversos , Metotrexato/efectos adversos , Neutropenia/inducido químicamente , Pulpitis/fisiopatología , Animales , Pulpa Dental/microbiología , Pulpa Dental/patología , Exposición de la Pulpa Dental/complicaciones , Necrosis de la Pulpa Dental/microbiología , Necrosis de la Pulpa Dental/fisiopatología , Inmunohistoquímica , Recuento de Leucocitos , Recuento de Linfocitos , Masculino , Diente Molar , Neutropenia/fisiopatología , Infiltración Neutrófila/fisiología , Neutrófilos/efectos de los fármacos , Neutrófilos/patología , Neutrófilos/fisiología , Absceso Periapical/microbiología , Absceso Periapical/fisiopatología , Tejido Periapical/microbiología , Tejido Periapical/patología , Pulpitis/etiología , Pulpitis/microbiología , Ratas , Ratas Wistar , Estadísticas no Paramétricas , Factores de TiempoRESUMEN
OBJECTIVE: The purpose of this study was to investigate the relationship between type 2 diabetes mellitus and anaerobic bacteria detected in infected root canals. STUDY DESIGN: Normal Wistar rats (control) received a standard laboratory diet with water (group A), and GK rats (type 2 diabetes mellitus rats) a normal laboratory diet with water (group B) or a 30% sucrose solution (group C). Chemotaxis assay was conducted on polymorphonuclear leukocytes from the 3 groups, and the numbers of anaerobic bacteria in infected root canals were determined. RESULTS: In the chemotaxis assay on the polymorphonuclear leukocytes, the chemotactic response of cells in group C was lower than that for groups A and B (P < .01). As to bacteria detected in the root canal, obligate anaerobic bacteria which stained gram negative, were significantly more numerous in group C (P < .01) than in groups A and B. CONCLUSION: The metabolic condition produced by type 2 diabetes mellitus in rats might lower the general host resistance against bacterial infection.