The laser systems as well as PAD were less effective than NaOCl in reducing E. faecalis, both in aqueous suspension and in the infected tooth model.

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Aims:  To evaluate the use of the modified Robbins device (MRD) to test disinfection strategies against biofilms that form on oral medical devices and to test the biofilm removal efficacy of NitrAdineTM, a disinfectant for the maintenance of oral medical devices. Methods and Results:  Biofilms were grown on discs using the MRD and biofilms formed in this system were used to evaluate the efficacy of NitrAdineTM and to determine the optimal disinfection conditions. Our data indicate that the use of the MRD allows for the rapid and reproducible formation of high‐density biofilms. Determination of the efficacy of NitrAdineTM revealed high activity against biofilms tested (e.g. >3 log reduction for Candida albicans and Staphylococcus aureus) and allowed the determination of the optimal conditions for its use. Conclusion:  The high reproducibility and flexibility of the MRD make it an excellent candidate for standardized testing of disinfectants aimed at reducing biofilms on oral medical devices. Using this system, we were able to demonstrate that NitrAdineTM exhibits high activity against biofilms formed by the micro‐organisms tested. Significance and Impact of the Study:  Our data suggest that our procedure is appropriate for standardized testing of disinfectants aimed at reducing biofilms on oral medical devices.

Aims:  To evaluate the susceptibility to microbial contamination that occurs during simulated handling of protective devices for the preparation of cytotoxic drug solutions. Methods and Results:  Four devices, i.e. Chemoprotect spike, Clave connector, PhaSeal and Securmix were challenged with low and high inocula of micro‐organisms. The cells, transferred to the connected vials during repeated manipulations of the devices were counted by means of solid‐phase cytometry. Of the four devices, PhaSeal afforded the lowest transfer of micro‐organisms. Secondly, the efficiency of procedures for the disinfection of an artificially contaminated rubber stopper was compared prior to connection of the vial to the PhaSeal device. Spraying or swabbing alone was inadequate, as opposed to a combination of spraying [0·5% or 2·0% (w/v) chlorhexidine in isopropanol] and swabbing [70% (v/v) isopropanol]. Conclusions:  Although Phaseal afforded the lowest transfer of micro‐organisms, adequate disinfection of the vial prior to connection remains required. Significance and Impact of the Study:  Unlike aspects of operator protection, which are well documented, the microbiological safety of protective devices for the preparation of cytotoxic drugs has not been addressed in the literature. This study estimates the susceptibility to microbial contamination during handling of four commonly used devices.

Candida albicans biofilms are a major cause of voice prosthesis deterioration in laryngectomized patients. The aim of this study was to produce a surface capable of inhibiting C. albicans biofilm formation. Dimethylaminoethylmethacrylate (DMAEMA) and polyethylenimine (PEI) moieties were covalently bound to the surface of polydimethylsiloxane (PDMS) or polymethylmethacrylate (PMMA) and subsequently quaternized. Physicochemical characterization of the grafted surfaces was carried out and their effect on C. albicans cell numbers was assessed using a modified Robbins device to grow the biofilms. Covalently bound quaternized polyDMAEMA (polyDMAEMAq) and PEI (PEIq) inhibited biofilm growth, with reductions up to 92%. Our approach may show promise for future application in medical devices such as catheters and prostheses.