Investigating steam penetration using thermometric methods in dental handpieces with narrow internal lumens during sterilizing processes with non-vacuum or vacuum processes

Winter, S., Smith, A. , Lappin, D., McDonagh, G. and Kirk, B. (2017) Investigating steam penetration using thermometric methods in dental handpieces with narrow internal lumens during sterilizing processes with non-vacuum or vacuum processes. Journal of Hospital Infection, 97(4), pp. 338-342. (doi: 10.1016/j.jhin.2017.07.033) (PMID:28778810)

[img]
Preview
Text
145250.pdf - Accepted Version

598kB

Abstract

Background: Dental handpieces are required to be sterilized between patient use. Vacuum steam sterilization processes with fractionated pre/post-vacuum phases or unique cycles for specified medical devices, are required for hollow instruments with internal lumens to assure successful air removal. Entrapped air will compromise achievement of required sterilization conditions. Many countries and professional organisations still advocate non-vacuum sterilization processes for these devices. Aim: To investigate non-vacuum downward/gravity displacement, type-N steam sterilization of dental handpieces, using thermometric methods to measure time to achieve sterilization temperature at different handpiece locations. Methods: Measurements at different positions within air turbines were undertaken with thermocouples and dataloggers. Two examples of commonly used UK benchtop steam sterilizers were tested; a non-vacuum benchtop sterilizer (Little Sister 3, Eschmann, UK) and a vacuum benchtop sterilizer (Lisa, W&H, Austria). Each sterilizer cycle was completed with three handpieces and each cycle in triplicate. Findings: A total of 140 measurements inside dental handpiece lumens were recorded. We demonstrate that the non-vacuum process fails (time range 0-150 seconds) to reliably achieve sterilization temperatures within the time limit specified by the International standard (15 seconds equilibration time). The measurement point at the base of the handpiece failed in all test runs (n=9) to meet the standard. No failures were detected with the vacuum steam sterilization type B process with fractionated pre-vacuum and post-vacuum phases. Conclusion: Non-vacuum downward/gravity displacement, type-N steam sterilization processes are unreliable in achieving sterilization conditions inside dental handpieces and the base of the handpiece is the site most likely to fail.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Lappin, Dr David and McDonagh, Mr George and Winter, Ms Sandra and Smith, Professor Andrew
Authors: Winter, S., Smith, A., Lappin, D., McDonagh, G., and Kirk, B.
College/School:College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing > Dental School
Journal Name:Journal of Hospital Infection
Publisher:Elsevier
ISSN:0195-6701
ISSN (Online):1532-2939
Published Online:02 August 2017
Copyright Holders:Copyright © 2017 The Healthcare Infection Society
First Published:First published in Journal of Hospital Infection 97(4): 338-342
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

University Staff: Request a correction | Enlighten Editors: Update this record