Evaluation of the potential risk of occupational asthma in dentists exposed to contaminated dental unit waterlines.

Introduction: Most of the organisms isolated from dental unit waterlines (DUWL) are Gram-negative bacteria, which contain cell wall endotoxin. A consequence of endotoxin exposure is the exacerbation of asthma.

Objectives: This study examined the prevalence and onset of asthma among dentists and determined whether or not these were associated with the microbiological quality of DUWL in their practices.