SEPTEMBER 2012 www.dimensionsofdentalhygiene.com Dimensions OF DENTAL HYGIENE 25

Ergonomics has revamped the dentaloffice and drastically improved the phys-ical health of dental professionals in theworkplace. Magnification loupes are a well-known, evi-

dence-based ergonomic tool that improves clinicians’

posture. Coaxial illumination, often used in tandem

with loupes, is not as well researched as magnifica-

tion but it can offer ergonomic benefits as well. Orig-

inally designed for surgeons, coaxial illumination has

been used in the dental arena since the 1980s. It pro-

vides a light source that is parallel to the sight line,

which helps prevent shadows in the mouth that

impede a clinicians’ view.1

Also called headlights, earlier coaxial illumination

models used fiber optic, halide, halogen, and xenon

lights.2 New versions include a light emitting diode

(LED). LED technology has drastically changed the world

of lighting, with applications ranging from Christmas

lights to car headlights. LEDs are small light blubs in an

electrical circuit that produce a full spectrum of white

light, without creating excessive heat, through the

movement of electrons.3 They are incredibly long-lasting

with a life expectancy of 50,000 hours.4 If used during a

typical 32 hour work week in the dental office, LED lights

will last approximately 30 years.

FEATURESCoaxial illumination enhances magnification, improv-

ing the field of vision. Headlights increase operator

comfort by providing a clear field, reducing eye strain,

and encouraging a neutral position by eliminating the

need to hunch over to improve vision.5 Inadequate

By Emily R. Holt, RDH, MHA, CDA, and

Roberta Hoebeke, RN, PhD, FNP-BC

Shine aLight

Coaxial illumination can help dentalprofessionals improve their field of visionwhile also providing ergonomic benefits.

Emily R. Holt, RDH, MHA, CDA, (left) isa clinical assistant professor of dentalhygiene and dental assisting at the University of South ern Indiana in Evans-ville, Ind. Roberta Hoebeke, RN, PhD, FNP-BC,(right) is an associate professor of nursingin the family nurse practitioner programat the University of Southern Indiana.

26 Dimensions OF DENTAL HYGIENE www.dimensionsofdentalhygiene.com SEPTEMBER 2012

lighting makes it difficult to assess patient needs and deliver quality

care. In addition, it can lead to eyestrain and poor posture.6 The

intraoral working field should be a minimum of three times brighter

than surrounding areas1 and more light is needed when performing

close-up, detailed tasks. Headlights offer the ability to adjust the

intraoral lighting to meet the appropriate contrast with adjacent

structures.

Coaxial illumination can be key for dental

hygienists who have declining vision. The aging

process increases the lighting needed to per-

form detailed tasks.7 The desired level of bright-

ness varies according to the operator’s age as

well as the size of the objects being examined.1

The adjustment knob on the battery pack

allows the practitioner to adjust the brightness

for different procedures to achieve optimal visi-

bility and comfort.1

Working with the appropriate amount of light

is important, but esthetic work requires viewing

teeth in a natural light. Gone are the days when

the overhead light had to be turned off in order

to obtain a shade match on teeth. LED head-

lights provide a much more natural color than

overhead lighting. Figure 1 and Figure 2 demon-

strate the difference in color when using an LED

headlight vs an overhead light. The LED displays

a natural light comparable to sunlight while the

overhead lighting creates a yellow cast.5

Coaxial illumination systems are now quite compact, fully

portable, and hands free. Headlights remove the need for an over-

head light and they work during power outages. Because they rarely

require adjustment during treatment, headlights

may help dental professionals save time during

procedures. Their use may also reduce stress in

the muscles of the arm, shoulder, and upper back

caused by lifting the arm repeatedly to adjust an

overhead light. Coaxial illumination lights all

areas of the mouth equally, even areas typically

covered in shadows, such as the back of the

mouth.

ERGONOMIC BENEFITSHeadlights facilitate ergonomically correct posture by providing

shadow-free illumination that allows clinicians to remain in a

neutral position instead of leaning or lurching forward.1 Wearing

a headlight eliminates the need to bend the neck, which creates

poor posture and leads to musculoskeletal injury. Coaxial illumi-

nation also provides optimal lighting that is parallel to or within

15° of the clinician’s line of sight.8 This can be difficult to achieve

with overhead lighting.

CONCERNS Clinicians may be leary of trying something “new” to them, although

coaxial illumination has been around for decades. Asking other den-

tal colleagues about their experience with headlights is helpful as is

speaking with manufacturers about their products. Cost is a factor

and headlights range from as low as $400 to as high as $2,000.

Patients who have not seen a dental hygienist wearing a headlight

may be initially surprised. To minimize the view

of the cord and battery pack, run the cord

under a lab jacket or top while keeping the bat-

tery pack attached at the waist (Figure 3).

The ability to adequately disinfect a head-

light is also a concern. However, headlights

reduce the risk of cross-contamination because

the light is not adjusted during treatment so

there is no hand-to-light transfer of pathogens.

The light can be turned on and off before and

after donning gloves. To eliminate potential

aerosol contamination, headlights can be disin-

fected. The manufacturer instructions should be

followed to effectively disinfect without dam-

aging the system.6

PRODUCT CONSIDERATIONSWhen choosing a headlight system, several

factors should be considered. The light color

temperature (the color of the light emitted by

the LED) determines how closely the lighting

resembles natural sunlight as opposed to casting a yellow or blue

shade over the working field.5 A more yellow appearance is created

by lower color temperatures whereas a bluer cast is generated by

higher temperatures.6 Optimal color temperature should range

Figure 1. The color of dentitionunder the illumination of a lightemitting diode (LED) headlight.

Figure 2. The same dentition from Figure 1illuminated by a traditional overhead light in adental operatory.

Figure 3. The cord and battery pack can beconcealed by wearing the cord underneath a labcoat or scrub top and keeping the battery packattached to the waist.

Figure 5. Mounting clip that attaches the headlightto the loupes.

Figure 4. A curing filter can be placed over theheadlight to prevent premature curing of

SEPTEMBER 2012 www.dimensionsofdentalhygiene.com Dimensions OF DENTAL HYGIENE 27

between 5,500º and 6,500º Kelvin. To most closely resemble natu-

ral sunlight, a color temperature of 5500º Kelvin is ideal.5

The intensity or brightness of the light produced by the head-

light, which is measured in foot candles, should be adjustable. The

spot size of the light (actual size of the illuminated space), some-

times referred to as the footprint, is another important factor.4 Cur-

ing filters are also available that can be moved to cover the beam to

prevent premature curing of materials (Figure 4).

The weight of the headlight is also important. A lightweight illu-

mination device is more apt to prevent additional musculoskeletal

injuries. Companies differ in how they measure the weight of their

products. Some include the weight of the cable in their measurement

while others only note the weight of the lighting device. Some of the

newest lights weigh as little as 5 grams alone and 16 grams including

the cable.

The battery life can also impact workday productivity. Many batter-

ies last between 6 hours and 8 hours before they need to be charged.

Charging times vary between 2 hours and 4 hours. By purchasing two

batteries, clinicians can use one battery while the other is charged.

Using lithium ion batteries, which last between 1 year and 2 years, is

an option. Batteries are less able to hold their charge as they age and

should be replaced once their operating time has been compromised.5

Purchasing the headlight and loupes from the same manufac-

turer assures a stable connection. When purchased separately, it is

important to make sure the device mounts properly to an existing

pair of loupes. Mounting clips are versatile and adapt to various

frame styles within a wide range of manufacturers. Some companies

produce lights and frames with a male and female receptor that con-

nect together (Figure 5).

Headlights produce electromagnetic current, similar to cell

phones, and are in close proximity to neural structures when worn.

Cable insulation protects the clinician from electromagnetic current.

Not all companies offer this, so it is important to determine if cable

shielding is included. Quiet operation and a quality warranty are also

desirable features.

Coaxial illumination systems are important accessories in the den-

tal operatory and they offer many benefits for clinicians. Thorough

research on the different products available will help dental profes-

sionals upgrade to the best headlight to suit their practice needs.

REFERENCES1. Branson B, Simmer-Beck M. Visual acuity without injury. Dimensions ofDental Hygiene. 2009;7(9):46–49.

2. United States Air Force Dental Evaluation and Consultation Service. Synopsisof headlights for dentistry and surgery. Available at: http://airforcemedicine.afms.mil/idc/groups/public/documents/afms/ctb_109457.pdf. Accessed August16, 2012.

3. Angelle A. Will LED light bulbs best your CFLs and incandescents? PopularMechanics. August 10, 2010.

4. Draper C. Magnification and illumination. Access. 2010;24(5):20.

5. Marsh L. Practicing ergonomically correct dental hygiene. Dimensions ofDental Hygiene. 2009;7(1):22–23.

6. Guignon AN. Lighting our world. Available at: www.centennialbulb.org/news/0602rdhill.pdf. Accessed August 16, 2012.

7. Owsley C. Aging and vision. Vision Res. 2011;51:1610–1622.

8. Murphy DC. Ergo nomics and the Dental Care Worker. Washington, DC:American Public Health Association; 1998:246–311.

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