An investigation into the biofilm-associated bacterial contamination of dental chair units and dental unit output water supplies and its control
Citation:Claire M. Tuttlebee, 'An investigation into the biofilm-associated bacterial contamination of dental chair units and dental unit output water supplies and its control', [thesis], Trinity College (Dublin, Ireland). School of Dental Science, 2005, pp 218
Tuttlebee TCD THESIS 7391 An investigation.pdf (PDF) 140.4Mb
Many modern medical devices, including dental chair units (DCUs), are potential reservoirs of infection as they can harbour biofilm-associated microorganisms. This study investigated several aspects of DCUs related to cross-infection, particularly microbial contamination of dental unit waterline (DUW) output water and DCU suction systems. The first part of this study evaluated the efficacy of the novel Planmeca Waterline Cleaning System, the first integrated disinfection system specifically designed for the disinfection of DUWs, with the two hydrogen peroxide-based disinfectants Sterilex Ultra and Sanosil at reducing bacterial contamination of DUW output water in the Dublin Dental Hospital to safe levels (< 200 cfu/ml). Ten DCUs were retrofitted with the novel system: Sterilex Ultra and Sanosil were used weekly to disinfect six and four of these DCUs, respectively, over a 20-week and eight-week period, respectively. Both disinfectants were equally effective at reducing the bacterial density of DUW output water to < 200 cfu/ml and maintaining this water quality for at least a week. Following cessation of once-weekly disinfection with either disinfectant, DUW output water quality deteriorated within three weeks. Electron and confocal microscopy of the internal lumens of DUWs demonstrated that the improved water quality correlated with biofilm removal. Sanosil was found to be more effective, as the use of Sterilex Ultra was associated with clogging of DUWs in some DCUs. Following completion of this study all DCUs in the Hospital were retrofitted with the system. Two years after the implementation of weekly disinfection with Sanosil throughout the Hospital, it was noted that bacterial densities rose to significant levels five days following disinfection, which correlated with a significant increase in the prevalence of catalase-positive organisms in the DUW output water, probably due to the consistent use of the hydrogen- peroxide based disinfectant Sanosil.
Author: Tuttlebee, Claire M.
Qualification name:Doctor of Philosophy (Ph.D.)
Publisher:Trinity College (Dublin, Ireland). School of Dental Science
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Type of material:thesis
Availability:Full text available