dental engine dental engine a dental engine is a large chair-side appliance (often including the dental chair itself) for use in a dentist's office. dental chair integrated with a dental engine kneebreak dental chair from belmont. history would suggest that an american dentist, josiah flagg, created the first adjustable dental chair in the late 18th century, adapting a wooden chair by adding an instrument tray on one side, as well as a movable headrest. over the years this equipment has evolved and, perhaps most excitingly, in the 20th century, the first-ever treatment unit came into being, incorporating air, water, gas, and electricity into one handy piece of equipment. at this point, while patients were sitting more comfortably than ever before, for the most part, dentists were still standing – and their backs and necks were not thanking them for it. by 1958, however, john naughton had created a chair with an articulated seat and back, which marked the introduction of what we now call four-handed dentistry. at minimum, a dental chair serves as a source of mechanical or pneumatic power for one or more handpieces. typically, it will also include a small faucet and a spit-sink, which the patient can use for rinsing, as well as one or more suction hoses, and a compressed air/irrigation water nozzle for blowing or washing debris clear of the work area in the patient's mouth. the equipment possibly includes an ultrasonic cleaning appliance, as well as a small table to hold the instrument tray, a operating light, and possibly a computer monitor or display. led operating lights have completely transformed the user experience in recent years providing a 'cool' light, with a bulb that doesn't need changing and which floods the oral cavity with a light distribution that reduces shadows, and in turn eye strain. a light with a high colour rendering index accurately reflects colour for soft and hard tissue diagnosis; some lights also have a useful composite mode, which illuminates without curing photo-initiated resins. due to their design and usage, dental chairs are a potential source of infection from several kinds of bacteria, including legionella pneumophila . gallery close view of dental chair with various visible parts modern pelton & crane chair in dental office hospital dental treatment area dental engine in north cameroon.