Biofilm and the Dental Office

Electro-chemically activated water in dental unit water lines

“…15,[20][21][22][23] Some of these pathogens are known to flourish in the aqueous environment and are a major cause of nosocomial infections, resulting not infrequently in death. [24][25] Herein lies the danger of DUWL biofilm contamination. The mere presence of the bacteria in the DUWL, even in the very large numbers reported (more than 1 million organisms per millimeter), is not presently viewed as a major health threat to the general population.…”

“…However some very real concern has been expressed by many about the threat that these opportunistic pathogens may pose to the ever increasing population of immunocompromised patients. 5,[25][26][27] Two cases of postoperative infections in cancer patients, caused by Pseudomonas aeruginosa apparently originating from dental unit water, have been reported. 5 The implications of potential pathogens being iatrogenically transmitted to patients undergoing dental treatment are serious.…”

“…[29][30][31] The American Dental Association (ADA) is concerned about these problems and adopted a statement on December 13, 1995, identifying it as one of the critical research areas in dentistry today. 25 The ADA set a number of less than 200 colony forming units per millilitre as the goal to be reached by all members by the year 2000.…”

Prevalence of legionella waterline contamination and Legionella pneumophila antibodies in general dental practitioners in London and rural Northern Ireland

“…1 Biofilm formation occurs on the inner surface of the waterlines as a result of water stagnation in microbore tubing and intermittent patterns of water use, combined with poor waterline management, which culminates in the generation of contaminated aerosols. 2,3 In order to multiply, legionellae need other microorganisms and a supply of nutrients and temperatures in the range of 20-45°C; 4 they will not proliferate in sterile water. Sludge at the base of water storage tanks and the micro-habitat within the DUWL biofilm provide favourable conditions for the colonisation and growth of legionellae within plumbing systems.…”

First report of an acute purulent maxillary sinusitis caused by Pseudomonas aeruginosa secondary to dental implant placement in an immunocompetent patient

“…In particular, biofilms -sessile microbial communities exhibiting greater resistance to surfactants, biocides and antibiotics than their planktonic counterpart 10 -can constantly release bacteria, 11 thus providing a reservoir for continuous high-level contamination of DUWLs. 6,12,13 P. aeruginosa is the most frequent contaminant of DUWLs, being isolated in up to 50% of samples of dental unit water at concentrations of up to 2 × 10 5 CFU/ml. [13][14][15][16] This microorganism is able to thrive in low nutrient environments such as distilled water, often exhibits resistance to antibiotics and disinfectants such as chlorhexidine and iodophors, 17 and it is able to form biofilms in DUWLs, where it not only survives but proliferates waiting for susceptible hosts.…”