sodium-hypochlorite and dodicin

Opportunistic infections caused by gram-negative rods (GNR), conventionally regarded as organisms with low or no pathogenicity, and intractable infections caused by various resistant organisms pose a great problem now. In view of this, we determined the bactericidal effects of 5 commonly used disinfectants using as the test strains Xanthomonas maltophilia and Serratia marcescens, chosen among other GNR since they often cause nosocomial infections. Regarding the bactericidal activities against X. maltophilia and S. marcescens, both sensitive strains and resistant strains were killed within 20 s of exposure to povidone-iodine and sodium hypochlorite. With chlorhexidine, 1 strain each of both species was not killed within 10 min of exposure at a concentration of 0.2%. Both sensitive strains and resistant strains of X. maltophilia were killed within 20 s of exposure to benzalkonium at 0.02%, while a concentration of 0.1% was required for benzalkonium to kill S. marcescens within 20 s. With Tego-51, both sensitive strains and resistant strains of X. maltophilia were killed within 20 s at 0.02%, while 1 strain of S. marcescens was not killed within 20 s at a concentration of 0.1%. In the use of disinfectants, comparative bactericidal effects of various disinfectants against clinical isolates should be taken into consideration.

Topics: Anti-Infective Agents, Local; Benzalkonium Compounds; Chlorhexidine; Cross Infection; Disinfectants; Drug Resistance, Microbial; Glycine; Gram-Negative Bacterial Infections; Humans; Iodophors; Opportunistic Infections; Povidone-Iodine; Serratia Infections; Serratia marcescens; Sodium Hypochlorite; Time Factors; Xanthomonas

The perforated irrigation needle was used to test a high-volume (20 c.c.) final flush of prepared root canals. Three solutions: TEGO 1 percent, NaOCl 5.25 percent, and REDTA were tested. The roots were split longitudinally and were prepared for examination under the scanning electron microscope immediately after preparation and final flushing. In addition, groups were prepared and flushed in the same manner, but after splitting they were soaked in the respective solutions for 3 hours and then examined. The results indicated that the smeared layer is caused by instrumentation, that it is not removed by TEGO or NaOCl, and that it is removed by REDTA. It may be that the smeared layer is a slurry of dentin filings, since REDTA does not remove soft tissue. All solutions produced a canal quite free of debris; however, none of the tested irrigants was completely satisfactory by itself.

Topics: Dentin; Edetic Acid; Glycine; Humans; Microscopy, Electron, Scanning; Needles; Root Canal Therapy; Sodium Hypochlorite; Therapeutic Irrigation