title: Influence of Temperature on the Antibacterial Activity of Sodium Hypochlorite.
abstract: The aim of this study was to compare the antimicrobial activity of 5.25% NaOCl, Hypoclean and Chlor-Xtra at 20 °C and 45 °C in bovine root dentin. One-hundred-and-seventy dentin tubes prepared from bovine maxillary incisors were infected for 21 days with Enterococcus faecalis. The specimens were divided into the following groups: 1. 5.25% NaOCl 20 °C; 2. Hypoclean 20 °C; 3. Chlor-Xtra 20 °C; 4. 5.25% % NaOCl 45 °C; 5. Hypoclean 45 °C; 6. Chlor-Xtra 45 °C; 7. positive control; 8. negative control. Dentin chips were collected with round burs into Brain Heart Infusion (BHI) broth. After culturing, the number of colony-forming units (CFU) was counted. Statistical analyses were performed using descriptive statistics (mean, standard deviation, median), Shapiro-Wilk test, ANOVA and Tukey test. Significance level was set at p<0.05. In all experimental groups, CFU was minimum after treatment (day 0) and the obtained results were significantly different from each other at any period (p<0.05). After treatment, the Hypoclean and Chlor-Xtra showed the lowest numbers of CFU at 20 °C and 45 °C, whereas 5.25% NaOCl showed the highest number of CFU at both temperatures. In each group, the number of CFUs increased significantly with time (p<0.05). The antibacterial activity of Hypoclean and Chlor-Xtra at 45 °C were significantly greater than other tested solutions.
authors.affiliation: Private Practice, Crotone, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Giardino
authors.affiliation: Institute of Dental Sciences Shahid Beheshti, University of Medical Sciences, Tehran, Iran.
authors.forename: Zahed
authors.initials: Z
authors.lastname: Mohammadi
authors.affiliation: University of Pavia, Pavia, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Beltrami
authors.affiliation: University of Pavia, Pavia, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Poggio
authors.affiliation: Universidade Federal de Goiás, Goiânia, GO, Brazil.
authors.forename: Carlos
authors.initials: C
authors.lastname: Estrela
authors.affiliation: University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Generali
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002417:Cattle; D012973:Sodium Hypochlorite / Q000494:pharmacology*; D013696:Temperature; D014092:Tooth Root / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D012973:Sodium Hypochlorite