title: An agar diffusion comparison of the antimicrobial effect of calcium hydroxide at five different concentrations with three different vehicles.
abstract: The purpose of this study was to determine if varying the percent (by weight) of aqueous calcium hydroxide or using different vehicles had an effect on its antibacterial efficacy against common endodontic pathogens in a pour plate/traditional streak agar diffusion model. Mixtures of calcium hydroxide powder and sterile saline in 40, 50 and 60 percent concentrations and the commercial preparations UltraCal XS and Vitapex were tested against six known endodontic pathogens with an agar diffusion method. Each medicament was placed in one of five wells, in each of 10 agar plates (n = 10), for cultures of each bacterial species. Zones of inhibition were measured after 48 hours incubation for aerobes and 96 hours incubation for anaerobes. Multiple one-way analyses of variance and post-hoc Student Neuman Keuls evaluated the data at alpha = 0.05. Larger zones of inhibition were consistently observed for higher concentrations of calcium hydroxide with statistical significance among the bacteria, particularly between 40% and 60%. Vitapex had significantly smaller zones of inhibition than all other medicaments and 35% UltraCal XS with methylcellulose was nearly as effective as 50% Ca(OH)(2) in inhibitory activity. Formulations containing 50-60% Ca(OH)(2) or 35% Ca(OH)(2) with aqueous methylcellulose are recommended as endodontic interappointment medicaments.
authors.affiliation: Naval Postgraduate Dental School, Bethesda, MD, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Blanscet
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Tordik
authors.forename: Gary G
authors.initials: GG
authors.lastname: Goodell
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects; D002126:Calcium Hydroxide / Q000008:administration & dosage / Q000494:pharmacology*; D002626:Chemistry, Pharmaceutical; D015169:Colony Count, Microbial; D003788:Dental Pulp Diseases / Q000382:microbiology; D004338:Drug Combinations; D013293:Enterococcus faecalis / Q000187:drug effects; D006801:Humans; D008422:Materials Testing; D008747:Methylcellulose; D014677:Pharmaceutical Vehicles; D045202:Porphyromonas endodontalis / Q000187:drug effects; D011208:Powders; D045242:Prevotella nigrescens / Q000187:drug effects; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants / Q000008:administration & dosage / Q000494:pharmacology*; D012828:Silicones / Q000494:pharmacology; D012965:Sodium Chloride; D013211:Staphylococcus aureus / Q000187:drug effects; D013298:Streptococcus sanguis / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D004338:Drug Combinations; D014677:Pharmaceutical Vehicles; D011208:Powders; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D012828:Silicones; C531021:UltraCal XS; C029584:calcium hydroxide, iodoform, silicone oil drug combination; D012965:Sodium Chloride; D008747:Methylcellulose; D002126:Calcium Hydroxide