Antimicrobial activity of sodium hypochlorite-based irrigating solutions.
OBJECTIVE
The objective of the present study was the in vitro evaluation of the antimicrobial activity of three different NaOCl-based endodontic irrigating solutions: a 5.25% conventional sodium hypochlorite solution; and two new irrigating solutions, a 5.25% sodium hypochlorite solution with the addition of a proteolytic enzyme and a surfactant; and a 5.25% sodium hypochlorite gel with inorganic silicate.


METHODS
Enterococcus faecalis, Staphylococcus aureus and Streptococcus mutans strains were selected to evaluate the antimicrobial activity of the endodontic irrigating solutions by the agar disc diffusion test. Paper disks were saturated with each one of the tested solutions (at room temperature and pre-warmed at 45°C) and placed onto culture agar-plates pre-adsorbed with bacterial cells and further incubated for 24 h at 37°C. The growth inhibition zones around each irrigating solution were recorded and compared for each bacterial strain.


RESULTS
The results were significantly different among the tested irrigating solutions: 5.25% sodium hypochlorite solution produced the highest inhibition areas; 5.25% sodium hypochlorite solution with a proteolytic enzyme and a surfactant, and 5.25% sodium hypochlorite gel with inorganic silicate showed the lowest zones of inhibition.


CONCLUSIONS
Even if all tested irrigating solution possessed antibacterial activity versus all tested bacterial strains, 5.25% sodium hypochlorite solution with a proteolytic enzyme and a surfactant, and 5.25% sodium hypochlorite gel with inorganic silicate showed lower in vitro efficacy than 5.25% conventional sodium hypochlorite solution.
Department of Endodontics, University of Pavia, Pavia, Italy. c.poggio@unipv.it
Claudio
C
Poggio
Carla Renata
CR
Arciola
Alberto
A
Dagna
Marco
M
Chiesa
Dario
D
Sforza
Livia
L
Visai
D000890:Anti-Infective Agents / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000201:enzymology; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000494:pharmacology; D052978:Disk Diffusion Antimicrobial Tests; D004708:Endodontics / Q000379:methods*; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000254:growth & development; D010447:Peptide Hydrolases / Q000302:isolation & purification / Q000494:pharmacology; D017640:Silicates / Q000494:pharmacology; D012973:Sodium Hypochlorite / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development; D013295:Streptococcus mutans / Q000187:drug effects* / Q000254:growth & development; D013501:Surface-Active Agents / Q000494:pharmacology; D007507:Therapeutic Irrigation
D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D017640:Silicates; D013501:Surface-Active Agents; D012973:Sodium Hypochlorite; D010447:Peptide Hydrolases