Changes in the Cultivable Flora in Deep Carious Lesions following a Stepwise Excavation Procedure

作者：Lars Bjørndal, Tove Eeg Larsen · 发表于：Caries Research · 年份：2000 · DOI：10.1159/000016631 · 被引用次数：219 · 研究领域：Oral microbiology and periodontitis research、Dental materials and restorations、Endodontics and Root Canal Treatments

This study examined the cultivable microflora before and after stepwise excavation procedures in deep carious lesions in 9 permanent teeth, categorized according to degrees of proximal surface destruction. The final excavation was performed 4-6 months after the initial treatment, which included peripheral dentine excavation and removal of the central cariogenic biomass and the superficial necrotic dentine. Dentine colour and consistency were assessed by means of standardized scales before the application of a Ca(OH)(2) compound and temporary sealing. Reassessments were performed before and after the final excavation. Microbiological samples of the central demineralized dentine were obtained with a sterile bur before and after the first excavation, as well as before and after the final excavation. After anaerobic cultivation on enriched non-selective tryptic soy agar, 30 colonies from a representative area were identified by standardized biochemical and physiological tests. Before temporary restoration, a yellowish and light brown demineralized soft dentine was typically observed, and gram-positive rods accounted for 70% and lactobacilli for 50% of the total colony-forming units. Lactobacillus casei subsp. rhamnosus and Actinomyces naeslundii dominated the lactobacilli and the other gram-positive rods, respectively. Gram-negative rods were the next most frequent isolates, followed by streptococci, each group accounting for about 20% of the colony-forming units in positive samp...