Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology
Effect of steam sterilization inside the turbine chambers of dental turbines☆,☆☆
Section snippets
Dental high-speed turbines
Twelve Super-Torque 630 B (KaVo A/S) HTs were included in the study. The turbines had been used for several months in operative dentistry. Before each experiment, the turbines were cleaned and lubricated and then sterilized in a vacuum autoclave (Selectomat-S-2000, MMM).
Cleaning and lubricating
KaVo’s Rotaspray II was used for cleaning and lubrication. Information on the exact composition of this cleaner/lubricant could not be obtained from the manufacturer.
Autoclaves
Four different non-vacuum autoclaves and one vacuum autoclave
Viable bacteria in turbine chambers after artificial contamination of HTs with human saliva
The number of viable bacteria in the pooled saliva cultured aerobically or anaerobically was at the level of 40 to 50 million CFU/mL. After cultivation of the contaminated turbine wheels, an average contamination of 500,000 CFU/mL (standard deviation, 720,000 CFU/mL) was found for the HTs that had been operated above the surface of saliva, and an average contamination of 1,300,000 CFU/mL (standard deviation, 1,700,000 CFU/mL) was found for the HTs that had been submerged in the saliva.
Survival of endospores of B stearothermophilus inside the turbine chambers after autoclavation
Table I
DISCUSSION
As noted previously, a potential risk for transmission of microorganisms from dental turbines has been demonstrated.14, 17 However, the documentation of simultaneous transmission of disease is still sparse. The possibility of cross contamination from one patient to another via an HT is primarily dependent on retraction of saliva into the turbine chamber. Therefore, the effect of autoclaving on HTs was studied with special interest in the killing effect inside the turbine chambers.
Recently, the
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Om smittrening av hand- ock vinkelstycken
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Cited by (21)
Autoclave sterilization of dental handpieces: A literature review
2020, Journal of Prosthodontic ResearchCitation Excerpt :In that study, none of the handpieces had bacteria according to the BI; however, a few of the CIs inserted in the turbine head showed sterilization fails (n = 2/304). Anderson et al. [30] sterilized dental air turbines contaminated with G. stearothermophilus and Streptococcus salivarius with a type B autoclave and using sterilization pouches. The researchers also tested the effects of cleaning and lubricating handpieces before autoclave sterilization.
Decontamination of dental devices in the hospital and general dental practice setting
2019, Decontamination in Hospitals and HealthcareFailure of non-vacuum steam sterilization processes for dental handpieces
2017, Journal of Hospital InfectionCitation Excerpt :The survival of bacterial endospores in this study following exposure (heat-up, plateau, and cool down) periods of 35 min and for some models of non-vacuum steam sterilizer plateau periods of 134°C for up to 6.5 min demonstrates gross failure of achievement of sterilization conditions within the inner locations of the handpieces. The ability of G. stearothermophilus spores placed in handpieces to survive steam sterilization has been reported by some but not all authors [25,26]. The variation in results is probably due to differences in equipment tested, BI bioburden, presentation and recovery.
Investigating steam penetration using thermometric methods in dental handpieces with narrow internal lumens during sterilizing processes with non-vacuum or vacuum processes
2017, Journal of Hospital InfectionCitation Excerpt :Using a vacuum steam sterilization type B process with fractionated pre-vacuum and post-vacuum cycle (Lisa, W&H), thermometric measurements showed a time difference of 0–3 s between the inside of the handpiece (location A) compared to the chamber of the sterilizer, 1–3 s in location B and –1–3 s in location C. No significant differences were observed between locations A, B, and C. Statistical analysis showed that the measured time delay in location C using a non-vacuum downward/gravity displacement type-N sterilizing process is significantly longer (P = 0.001) than all other location/thermocouple combinations and fails to meet an equilibration time to reach 134°C after 15 s compared to the chamber temperature. These investigations demonstrated that saturated steam penetrates lumens more successfully in vacuum steam sterilization type B cycles and that non-vacuum downward/gravity displacement type-N sterilizing processes are unreliable; this is in line with previous reports [20]. The key prerequisite for saturated steam to achieve the large release of energy required for sterilization is that water is at boiling point, where a change of phase (saturated steam/gas to water/liquid) can occur.
Infection and hazard controls
2014, Dental Secrets, Fourth EditionDecontamination in primary care: Dental and hospital perspectives
2013, Decontamination in Hospitals and Healthcare
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Reprint requests:Hans-Kristian Andersen,Danish Medicines Agency,Inspection and Medical Devices,Frederikssundsvej 378,DK-2700 Bronshoj,Denmark
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