Operatory Lighting: Controversies and Opportunities
by David J. Ahearn, DDS
Headlamps or track lighting – that's what we're talking about today. We all have our own preferences,
and there are noted pros and cons to every option. We've taken a pro-headlamp message
board and paired it up with an article on track-lighting benefits. Read both and jump back on the
message boards of Dentaltown.com to tell everyone which camp you're in.
In dentistry, new technologies bring with them challenges that shape the future of what
dentistry is and how dentistry is delivered. There are tipping points that occasionally make
change occur rapidly and, more commonly, gradual changes where new technologies are
assimilated into the old. Over the coming years, lighting will be one of those areas of change.
The history of lighting in dentistry reflects that of lighting technology in general. From
its inception, electric lighting technology has been good at general lighting and less so at
point source illumination. Further, lighting has historically been extremely inefficient with
much of the energy used to produce light being wasted as heat. Lighting is responsible for
35 percent of the energy cost in a typical inefficient office.¹ It can be even greater in hotter
climates, when the extra cost of air conditioning is factored in.
A further challenge in lighting design relates to the much quoted "accommodation
ratio," which states that the ratio between direct lighting (the light that is directly placed
upon a task) and ambient lighting (the general room light) should be no more than 3:1.²
This would mean that for a room illuminated to a recommended level of 300 footcandles
(fc) of general lighting, the intraoral light level would be no more than 900 fc. In today's
world, this is significantly and unrealistically low. The least powerful dental light is rated at
1500 fc (at 700 mm focal distance) and many dental headlights have illuminations
approaching 3000 fc, so no effort at satisfying this lighting requirement will ever be successful.
A treatment room with a background light level of 500 fc would be uncomfortably
bright, considered over-lighted and would likely exceed electrical power density standards
of most state energy codes.
This is the reason why headlight and microscope users often have trouble seeing outside
the oral cavity during treatment. The contrast ratio is simply too great to permit rapid
With so many negative feelings about lighting and its costs, it is not surprising that the
advent of improving technology in loupes and head lighting would lead to the concept that
dental intra-oral lights could be replaced by headlights completely. Indeed, we see a number
of practitioners around the globe are experimenting with headlights-only practice.
The potential benefits of a headlight-only practice are clear: reduced cost and simplified
operatory setup. This type of practice should be considered for startup and perhaps for high
volume, high room count offices. Certainly if the cost savings in lights permits the addition of
two more rooms, then the economics might dictate this, at least in the start-up phase.
Unfortunately, rarely is the lighting so costly as to eliminate the funding of more than one additional
room, at which point the benefits become less clear. Furthermore, converting to headlight-
only practice does present other problems. First and foremost is what to do about the
assistants. The solution here very much depends upon the degree to which assistants in your
practice actually provide care. If the care provided is limited to logistics and custodial care (moving
patients and sucking saliva), lights might not be required. However, if their practice includes
fabricating temporaries and prophy polishing, you will need to outfit them with lights, and this
most commonly means loupes as well. This diminishes cost savings significantly.
The question of what to do in hygiene is much more simple. This is an area where wide
field, relatively low-magnification loupes with headlights will have great benefit and very little
downside. If you have dedicated hygiene rooms, never do assisted procedures there and
all doctors wear headlights, you certainly can go headlight only here.
Unfortunately, what tends to happen is that once all the staff members are fitted with
quality loupes, the cost savings compared to lights is negligible. So what is it about dental
patient lights that causes doctors to hate them so much in the first place?
Why Most Patient Lights Are Inadequate
The most common and generally least expensive patient light-mounting method – the
chair mount – is also the least desirable and most trouble prone, with the combination of
both drift and vibration being the most common complaints. Chair-mount lights also
obstruct the operatory, which may be problematic with the use of some specialty equipment
such as sedation monitors and portable nitrous units.
Ceiling- and wall-mount lights are generally less aggravating to use with ceiling mounts
having a rather specific need for exact placement, lest the unit regularly become rotated such
that the operator or assistant must physically get up and use two hands to reposition the
lights. Wall mount units generally do not have this problem, however, due to their arm
length, they are much more susceptible to drift.
For more than 30 years, the gold standard in dental lighting has been ceiling-mounted,
dental-track lighting. Unfortunately, not all of these are universally great, but, there are a
number of very good products on the market which I would like to specifically
mention. The first is the A-dec 6300 (Fig. 1). A-dec's lights are universally known for their
flexible adjustability; their multi axis articulation eliminates much, if not all of the main
complaints regarding operatory lights. The second light of note is the Pelton & Crane
Helios 3000 (Fig. 2). This LED lighting system is the most energy efficient and advanced
product in terms of actual per watt light delivery by a good measure. Pelton has a decades-long
history of leadership in this segment.
Next I should mention the TLC light by the Technology Lighting Center (Fig. 3). This
light has perhaps more active fans and detractors than any other light. The TLC light contains
efficient spot lights to the oral field and therefore acts much more like a headlight than does any other extraoral lighting product. This light also includes full patient monitor integration
in both supine and upright positions.
The last light that I would mention is the Ergonomic Products TBL light, which is new
to the dental marketplace (Fig. 4). This light combines the features of the traditional track
light by having a wider visual field with patient video monitoring for supine patients and
then adds additional task lighting to critical work surfaces (to reduce the accommodation
problems of headlight wearers). In addition, the TBL created an entirely new option for
treatment illumination – single fixture mounting. The TBL light is an entire room solution
with no other light source needed for the entire installation.
For the mature general practice, intraoral dental lighting is here to stay. This will be
enhanced by headlights and perhaps only replaced entirely in a microscope exclusive practice,
which, for economic reasons, will continue to remain a rarity for some time.
There are a number of products that stand out from the field that will meet the needs
of virtually every practitioner without inconvenience or compromise, as a number of practitioners
continue to experiment with lightless practice.
1. 2005 Buildings Energy Data Book
2. Dental Clinics of North America, 1978
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|Dr. David Ahearn is a full time practicing dentist in Westport, Massachusetts. Though located in a small rural town, his office ranks
among the nation's most productive practices. Trained in prosthetics at the University of Michigan, Dr. Ahearn, like many of us, struggled
to reconcile the desire for the utmost quality with the requirements for practice success. His discovery and application of the principles
of the Toyota Production System in the early 90s began a quality and productivity revolution that is at the heart of his design work. As
the founder of Design/Ergonomics, Dr. Ahearn works with doctors across the country in designing comfortable, productive, and cost-effective
practices. He has held faculty positions at both the University of Michigan and NYU's College of Dentistry. He is also a founding member of
the ADA's Ergonomics Subcommittee and a contributor to numerous dental publications. He can be contacted at 508-636-6566 or 800-275-2547.