Well, the room must always be cleaned after any dental procedures, especially surgery. Everything must be sterilized from top to bottom, and urine on the chair is nothing compared to cleaning the filter on the cuspidor. I'd much rather clean poop off someone's butt than clean out the nasty jellied gunk that is the culmination of every rotton decaying mouth, blood, plaque, bacteria, and even bits of teeth...which is why I got out of that profession...though I'm still certified until 2012.