Scanning Electron Microscopic Observations And Microbial Study Of Periapical Biofilm In Chronic Periapical Periodontitis

Objective: To make an observation on the ultrastructure of periapical biofilm in chronic periapical periodontitis and to study bacteria in the biofilm in order to find out the species, constitution and origination of bacteria in periapical biofilm. Methods: Six teeth with chronic periapical periodontitis were collected and three of them were periapical granuloma, the others were chronic periapical abscess. A nomal tooth was collected as controls. The shape, distribution, bacteria and extracellular matrix of periapical biofilm were observed by scanning electron microscope. Periapical biofilm samples of twenty-five teeth with periapical periodontitis were collected by periapical surgery and bacterial samples of root canals were taken from twenty of twenty-five teeth. All the samples were inoculated, separated and purified according to usual practice. Identification of pure cultures was based on aerotolerance , colony and cell morphology , colony pigmentation , Gram-staining of cells and biochemical tests. The rates of detection and constitution of bacteria in...