title: Clinical investigation of the effect of calcium hydroxide intracanal dressing on bacterial lipopolysaccharide reduction from infected root canals.
abstract: The purpose of this clinical study was to determine the effect of 7 day intracanal dressing with calcium hydroxide on the amount of bacterial lipopolysaccharide (LPS; endotoxin) in human teeth with necrotic and infected pulp and apical periodontitis. Twenty-five single-rooted teeth with necrotic pulps and apical periodontitis were selected. Samples were collected before (S1), after root canal preparation (S2) and after 7 day intracanal dressing with calcium hydroxide (S3). The limulus amoebocyte lysate assay was used to quantify LPS. LPS was present in 100% of the root canals before (S1), after preparation (S2) and after 7 day intracanal dressing (S3). A significant reduction, equal to 29.54%, was found after root canal preparation (P < 0.05). A significant difference (equal to 25.26% reduction) was also detected between S2 and S3 (P < 0.05). Total endotoxin reduction (S3 compared with S1) was found to be 47.34%. Endotoxin concentration of the infected root canals was reduced after root canal preparation and also after 7 days of dressing of canals with calcium hydroxide; however, relatively high values of endotoxin remained in the root canals.
authors: Department of Endodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors: Alireza
authors: A
authors: Adl
authors: Mohammad
authors: M
authors: Motamedifar
authors: Mahdi Sedigh
authors: MS
authors: Shams
authors: Ahmad
authors: A
authors: Mirzaie
mesh_terms: D000328:Adult; D002126:Calcium Hydroxide / Q000008:administration & dosage* / Q000494:pharmacology; D003786:Dental Pulp Cavity / Q000382:microbiology*; D003790:Dental Pulp Necrosis / Q000382:microbiology; D006801:Humans; D008070:Lipopolysaccharides / Q000378:metabolism*; D008875:Middle Aged; D010485:Periapical Periodontitis / Q000382:microbiology; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D018915:Root Canal Preparation / Q000379:methods*
chemical_list: D008070:Lipopolysaccharides; D011135:Polysaccharides, Bacterial; D002126:Calcium Hydroxide
keywords: bacteria; calcium hydroxide; endotoxin; lipopolysaccharide; root canal