Decontamination efficacy of antiseptic agents on in vivo grown biofilms on rough titanium surfaces.

OBJECTIVE: Four common antimicrobial agents were evaluated for their efficacy in reduction of aerobic bacteria intraorally grown in biofilms on rough titanium samples. The solutions investigated contained chlorhexidine, essential oil, octenidine, or citric acid. METHOD AND MATERIALS: Twenty volunteers wore splints with titanium sleeves intraorally for 10 days. Following irrigation with the antiseptics, the sleeves were removed and biofilm samples were taken by swabbing. The bacteria were first examined microscopically by Gram staining. These samples from the surfaces were then cultured under aerobic conditions to identify and quantify the colonizing bacteria. RESULTS: Compared to untreated controls, significant (P < .05) differences in antimicrobial efficacy were observed for the different regimens depending on bacterial species or even the subtype. The reduction rates achieved varied from 30.0% after 2 minutes of rinsing with chlorhexidine to 99.8% after 8 minutes of rinsing with octenidine. CONCLUSION: The irrigation regimens studied in this investigation reduced bacterial colonization in a mature biofilm grown intraorally on rough titanium surfaces. The highest absolute reduction was achieved after 8 minutes, but only the 2-minute reduction rates are significant for clinical practice. Taking this into consideration, the distinct decontamination efficacy of octenidine and citric acid is evident.

Preoperative sterilization and disinfection of drill guide templates.

The aim of the in vitro study was to evaluate the decontamination potential of common antiseptic solutions for heat-sensitive implantological drill guide templates. One hundred implantologists were evaluated on the basis of a questionnaire for their measures of disinfection. On the basis of these results, 80% alcohol, Octenidine 0.1%, and Chlorhexidine 0.12% were tested in an in vitro model for their decontamination efficacy for heat-sensitive plastic material infected with Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus faecalis, Enterococcus faecium, Staphylococcus aureus, Enterobacter cloacae, Escherichia coli, and Candida albicans. The microorganisms were selected on the basis of results of environmental testing of dental laboratories. The results of the questionnaire revealed that Chlorhexidine was used by 30%, 80% alcohol by 23%, and Octenidine by 7% of the dentists. Using the in vitro model, with the exception of S. aureus, Chlorhexidine was not able to completely eliminate the microorganisms after 15 min of application. In contrast, the treatment with Octenidine revealed no further growth of the tested microorganisms after that time. The 80% alcohol was more efficient. No growth of microorganisms could be detected in any of the tests after 5 min of incubation. On the basis of our results and due to the fact that suitable installations for sterilization were hardly used by the dental practitioners, the disinfection of templates should be preferentially performed with 80% alcohol or Octenidine using an incubation time of 15 min with ultrasonication.

Decontamination of rough titanium surfaces with diode lasers: microbiological findings on in vivo grown biofilms.

OBJECTIVES: The bactericidal efficacy of diode lasers has already been demonstrated in vitro. We investigated the reduction of aerobe bacteria - colonizing rough titanium samples in biofilms intraorally grown - by diode lasers of different wave lengths. MATERIAL AND METHODS: Twenty-two volunteers participated in the trial. They were fitted for 10 days with custom-made intraoral plastic splints carrying titanium sleeves. A part of the sleeves was then irradiated with diode lasers in different modes. The other part remained non-irradiated and served as control. Directly after irradiation, the sleeves were swabbed and the gained bacteria were first examined microscopically and then were cultured under aerobic conditions. RESULTS: The bacteria in the controls and in the treated samples were quantified. A comparison with the controls revealed a marked overall reduction of bacterial colonization in all irradiated sleeves. Continuous irradiation for 20 s reduced bacteria counts by 99.67% at 810 nm and 99.58% at 980 nm. Repeating the 20 s exposure five times reduced counts by 99.98% at 810 nm and by 99.39% at 980 nm. A 98.86% reduction was seen after irradiation in pulsed mode. A further analysis in respect of different isolated bacteria revealed that the streptococci group was reduced by 99.29-99.99%, while the staphylococci group was reduced to a lesser extent in the range 94.67-99.99%. CONCLUSION: The results are of clinical relevance. In comparison with the mean bacterial counts of the untreated samples, all irradiation programs studied in this investigation reduced mean bacterial colonization in a biofilm on intraoral rough titanium surfaces by more than 98%. The actual extent of reduction was dependent on the bacteria species as well as on the irradiation mode.