Objectives:
To determine the bioburden of used handpieces from a dental hospital.
Methods:
Twenty used, unprocessed high & low speed and surgical handpieces (n=60)
were collected from the Sterile Service Department of the Glasgow dental
hospital. From these handpieces, the turbine or spray channel was aseptically
removed and added to 10/40 ml respectively of PBS and subjected to 5 minutes
sonication. A 100/200 µl eluant sample was cultured for the presence of
bacteria and fungi. The inner gear of used surgical handpieces was removed and
added to 50 ml of PBS. The gear was then subjected to 5 minutes of vortexing. A
200 µl sample of
this eluant was also cultured for bacteria and fungi. Isolates were identified
using Gram stain and biochemical profiles. For protein analysis, 10 ml of 1%
SDS was added to turbines and sonicated for 30 minutes. The protein content was
assessed using the OPA assay and SDS PAGE.
Results:
Summary
of microbial contamination of used dental handpieces
Handpiece | Mean cfu / ml | Range cfu / ml |
Turbine | 250 | 0 – 2420 |
High speed spray channel and turbine | 54 | 0 – 150 |
Low speed spray channel | 42 | 5 – 120 |
Surgical | 95 | 15 – 290 |
A
range of 0 – 52 µg/ml
of protein was detected in handpiece eluant.
Conclusions: This study provides a
quantitative analysis of the cultivable microbial flora fouling dental
handpieces prior to the decontamination process. Further work on the
qualitative analysis of contaminating proteins will allow a greater
understanding to optimise cleaning and sterilization of difficult to clean
instruments.