Comparison of antibacterial and toxic effects of various root canal irrigants.

AIM: To compare the antibacterial properties and toxicity of 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine gluconate and 0.2% chlorhexidine gluconate plus 0.2% cetrimide (Cetrexidin); Vebas, San Giuliano, Milan, Italy). METHODOLOGY: The antibacterial effects of the irrigants in vitro were examined after 5 min and 48 h in freshly extracted human teeth with single roots, whose canals were infected by Enterococcus faecalis ATCC 29212. In a separate in vivo study, bacterial culture samples were collected before treatment from the infected root canals of deciduous teeth containing necrotic pulp tissue. Irrigants were used to clean the canals which were then left empty for 48 h. Aerobic/facultative anaerobic and anaerobic bacterial growth were compared before and 48 h after irrigation. Finally, the toxic effects of the irrigants were assessed by injecting them into the subcutaneous tissues of rats. The inflammatory reactions that occurred 2 h, 48 h and 2 weeks after the injections were evaluated. RESULTS: In the laboratory study, the 2% chlorhexidine gluconate and Cetrexidin were significantly more effective on E. faecalis than the 5.25% NaOCl at 5 min (P < 0.05). Similarly, in the in vivo study, 2% chlorhexidine gluconate and Cetrexidin were significantly more effective on anaerobic bacteria than the 5.25% NaOCl at 48 h (P < 0.05). At the end of 2 weeks, the toxicity of the NaOCl solution was greater than that of the other irrigants (P < 0.05). CONCLUSIONS: Cetrexidin and 2% chlorhexidine gluconate were more effective, and had more residual antibacterial effects and lower toxicity than 5.25% NaOCl solution.

Fungal infections of the paranasal sinuses.

Fungal infections can be mainly grouped into four types. The invasive forms are acute sinusitis (fulminant), chronic sinusitis (indolent), whereas the non-invasive forms are mycetoma and allergic fungal sinusitis. From December 1993 to December 1997, 27 cases of fungal sinusitis, 22 of which were noninvasive forms, and 5 of which were invasive forms, were treated and are presented in this study. When we classified the patients with fungal sinusitis, 11 were diagnosed as mycetoma, 9 as allergic fungal sinusitis, 3 as acute fulminant sinusitis and 2 as chronic indolent sinusitis, while 2 patients were not included in our four groups of sinusitis. In all mycetoma cases the active agent was Aspergillus. Patients with non invasive forms of sinusitis were all treated with endoscopic sinus surgery. 2 of the patients with invasive forms of sinusitis underwent maxillectomy and they were given Amphotericin-B. With a mean follow up of 20 months, only 3 recurrences were seen. The infection recurred in 2 patients with allergic fungal sinusitis and 1 patient with chronic invasive sinusitis. However, 2 patients with acute fulminant invasive sinusitis died before they were operated on, and 1 patient died postoperatively.

In vitro susceptibility of Mycobacterium tuberculosis to fusidic acid.

The aim of this study was to determine the in vitro susceptibility of 170 clinical isolates of Mycobacterium tuberculosis to fusidic acid using a proportion dilution method. Nineteen isolates were resistant to at least one first-line anti-tuberculosis drug. A total of 1.8% of the isolates were resistant to fusidic acid. Fusidic acid should be evaluated clinically as a potential supplementary drug for the treatment of infections due to multidrug-resistant strains of M. tuberculosis.

Expression of P fimbriae of uropathogenic Escherichia coli strains.

The occurrence of P fimbriae in a total of 222 uropathogenic Escherichia coli (UPEC) strains was investigated. Out of the total, 31 (14%) were P fimbriated. Of 24 pyelonephritogenic E. coli strains, three (13%) with P fimbriae occurred in children with clinical pyelonephritis, and of 198 E. coli strains 29 (15%) occurred in children with cystitis. Prevalence of P fimbriae of E. coli strains was found to be quite similar in patients with cystitis and pyelonephritis