RESUMO
An animal model was developed in which the anti-inflammatory effects of dexamethasone could be examined histologically in periapical tissues following endodontic overinstrumentation. Mandibular first molars containing vital or partially necrotic pulp tissue were instrumented beyond the apical foramen in rats. Fifty microliters of sterile saline or dexamethasone sodium phosphate (0.4 mg/ml) were administered in a blind manner by supraperiosteal infiltration into the buccal vestibule. The rats were killed after 6, 24, and 48 h. Block sections of the mandibular molars were processed for histological examination and stained with hematoxylin and eosin. The number of polymorphonuclear neutrophils present in the periapical tissues was counted in a blind manner and statistical analysis of the results was performed by two-way analysis of variance. Following endodontic overinstrumentation, local infiltration of dexamethasone produced a significant anti-inflammatory effect on the periapical tissues of teeth with vital or partially necrotic pulp tissue.
Assuntos
Dexametasona/uso terapêutico , Periodontite Periapical/tratamento farmacológico , Análise de Variância , Animais , Masculino , Neutrófilos , Periodontite Periapical/etiologia , Ratos , Ratos Sprague-Dawley , Tratamento do Canal Radicular/efeitos adversos , Tratamento do Canal Radicular/instrumentação , Método Simples-CegoRESUMO
Biopsy reports from 150 periradicular tissue specimens obtained from teeth refractory to nonsurgical endodontic therapy were reviewed. The specimens were submitted by postdoctoral dental students in the Department of Endodontics, and the biopsy reports were prepared by oral pathologists at the University of Texas Health Science Center at San Antonio. The study found that 59.3% of the periradicular lesions were granulomas, 22% cysts, 12% scars, and 6.7% other pathoses. The majority (56%) of endodontically treated cases which failed to heal were recognized within 2 yr after the completion of therapy. The most common location for surgical retreatment was the anterior maxilla, followed by the posterior maxilla, the posterior mandible, and the anterior mandible. The periapical granuloma was the predominant pathosis at each location.
