Light Meters
REALITY’S CHOICES
1.
L.E.D. Radiometer
sds/Kerr
2.
Optilux Radiometer
sds/Kerr
3.
Cure Rite
Dentsply/Caulk
©2005 REALITY Publishing Co. Vol. 19
The Ratings
709
Light Meters
Dimensions
Digital or
Analog
Minimum
Tip Size
Battery
Power
Switch
Holds
Reading
Need to
Reset
Maximum Power
Reading
(mw/cm2)
Product
Cost
Length
Width
Thickness
L.E.D.
Radiometer
sds/Kerr
$183.35
4.75in/
12.1cm
3.0in/
7.6cm
1.1in/
2.9cm
Analog
7mm
No
No
No
No
2,000
Optilux
Radiometer
sds/Kerr
$183.35
4.75in/
12.1cm
3.0in/
7.6cm
1.1in/
2.9cm
Analog
7mm
No
No
No
No
1,000
Cure Rite
Dentsply/Caulk
$231.75
5.5in/
14.0cm
3.0in/
7.6cm
0.9in/
2.4cm
Digital
7mm
Yes
Yes
Yes
Yes
2,000
Light meters (also known as radiometers) allow you to check the
curing effectiveness of your curing lights quickly and efficiently by
measuring the amount of blue light (450-500nm) your curing
unit is emitting. It doesn’t really matter how bright your light
appears. As a matter of fact, many bright-appearing curing units
emit light outside the curing range. If the blue wavelength light is
not strong, no amount of brightness will cure light-sensitive materials thoroughly. You can do your own scrape tests, but that is
time-consuming and wastes composite. It is much easier to use a
light meter.
Undercuring can result from lack of power in the blue light
output. This means that a soft uncured layer can be left at the bottom of restorations. The real danger is that this lack of thorough
curing is likely to go unnoticed.
Light meters probably do not accurately compare one light to
another. However, light meters are useful when comparing individual lights for power loss. We suggest testing a light when it is
new and then retesting it every week. If the power has declined
more than 10% from when it was new, change the bulb and retest
the light. In addition, check each of your tips. Some tips may have
diminished capacity to get the curing power from the light to the
restoration. Keep your tips clean — resin adhering to the ends of
the light tips can reduce the amount of light irradiating the
restoration.
710
The Ratings
Test
Power readings from these meters were compared when measuring
several different lights. Results of these tests are:
Optilux
L.E.D.
Cure
Radiometer Radiometer Rite
Light
Type
Optilux 501
Hal
C75 Color Talk Hal
Spectrum 800 Hal
Radii
LED
LEDemetron 1 LED
SmartLite iQ
LED
Bluephase
LED
Tip
(mW/cm2)
11mm
733
11mm
942
11mmT
833
Integral
825
11mm
725
11mmT
600
10mm
985
(mW/cm2)
749
884
842
1000
713
640
863
(mW/cm2)
897
1,126
995
1,9871
766
643
850
Reading appeared for a brief viewing period and then the LCD
quickly reverted to a reading of 1.
1
The variability in these readings underscore our recommendation
not to use a meter reading to compare lights, but only to monitor
individual lights for degradation of their bulbs, filters, etc. In addition, this point can be further emphasized by our finding that even
different units of the same light meter can give different readings.
©2005 REALITY Publishing Co. Vol. 19
Light Meters
L.E.D. Radiometer
sds/Kerr
(4.6)
REALITY’S
CHOICES
1
NEW
Cost: $183.35
Warranty: 2 years
Description
Blue plastic. It has a recessed 7mm porthole that has a series of
concentric rings around it to help stabilize a curing tip. The rings
are also recessed on different levels. For example, the deepest ring
(flush with the light-sensitive porthole) is 9.7mm in diameter.
This ring would be used for 8mm tips. The next ring, slightly
(1.0mm) elevated from the first one, is 12.7mm in diameter and
would be used for 11mm tips. The last ring, also slightly elevated
from the previous one, is 14.7mm in diameter and would be used
for 13mm tips. It has an analog gauge, which reads in mW/cm2
from 0-2000 in 200mW/cm2 increments. Its name and abbreviated instructions are printed on the back of the unit.
Dimensions
Length
Width
Thickness
Measures all types of lights
Upper limit is 2,000 mW/cm2
Analog gauge not precise
Need to read while light is activated
Use
All you do is place your light tip over its porthole and activate the
light. The curing light actually supplies the power. There is no battery or on-off switch.
Directions
Plain paper sheets simply stapled, 16 languages. Gives good information in a logical manner. However, the recommendation to use
the enclosed Hardness Disk to check whether composite is cured
or not is probably not a good idea, since our tests show this
method of checking curing effectiveness is not reliable.
4.75in/12.1cm
3.0in/7.6cm
1.1in/2.9cm
Optilux Radiometer
sds/Kerr
(4.5)
REALITY’S
CHOICES
2
Cost: $183.35
Warranty: 1 year
Description
Off-white plastic. It has a recessed 7mm porthole that has a series
of concentric rings around it to help stabilize a curing tip. The
rings are also recessed on different levels. For example, the deepest
ring (flush with the light-sensitive porthole) is 9.7mm in diameter. This ring would be used for 8mm tips. The next ring, slightly
(1.0mm) elevated from the first one, is 12.7mm in diameter and
would be used for 11mm tips. The last ring, also slightly elevated
from the previous one, is 14.7mm in diameter and would be used
for 13mm tips. It has an analog gauge, which reads in mW/cm2
from 0-1000 in 100mW/cm2 increments. Its name and abbreviated instructions are printed on the back of the unit.
Dimensions
Length
Width
Thickness
4.75in/12.1cm
3.0in/7.6cm
1.1in/2.9cm
©2005 REALITY Publishing Co. Vol. 19
Easiest to use — not even a power switch
No resetting necessary after using
Analog gauge not precise
Need to read while light is activated
Use
All you do is place your light tip over its porthole and activate the
light. The curing light actually supplies the power. There is no battery or on-off switch.
Directions
Handbook, six languages. Gives good information in a logical
manner. However, the recommendation to use the enclosed
Hardness Disk to check whether composite is cured or not is
probably not a good idea, since our tests show this method of
checking curing effectiveness is not reliable.
The Ratings
711
Light Meters
Cure Rite
3
Dentsply/Caulk
(4.1)
Cost: $231.75
Warranty: 2 years
Digital readouts more precise
Holds reading after testing is completed
Most expensive in category
Turning it off and on for resetting can be a nuisance
Description
Off-white plastic. Printing on the front includes its name and designation as a light meter. It has a slightly recessed 6.6mm porthole,
but this slight recess does not help to stabilize a curing tip. It reads
output in mW/cm2 from 0-1999 in 1mW/cm2 increments on a
digital LCD. Its name and abbreviated instructions are printed on
the back of the unit. It will test tips from 7-15mm and requires a
9V battery. When the battery is insufficient, a “lo bat” message
will appear on the LCD. To change batteries, you must loosen
four screws on the back of the unit.
Dimensions
Length
Width
Thickness
5.5in/14.0cm
3.0in/7.6cm
0.9in/2.4cm
Use
The switch on the right side activates the unit, revealing the large
digital LCD display. This display makes it very easy to read the
output of a light. You place the curing light tip over the porthole
and the unit will display the reading. It takes 10-20 seconds to
reach its maximum reading and you should move the tip of your
light over the porthole to make sure its reading is accurate.
It maintains its reading even after you remove the light from
the porthole. However, the reading starts to decline almost immediately, so don’t delay in recording the score. You must turn the
unit off to cancel the reading and then on again to run another
test. Since the score is not lost immediately after removing the
light from the meter, you can use it to check extraoral curing lights
if you can fit it into the chamber.
Directions
Single sheet of folded plain paper. Information is presented well.
However, the warranty card states “to obtain the warranty
described in the operating manual...”. We would not consider the
single sheet a “manual” and there was nothing about the warranty
on the sheet.
REALITY
The L.E.D. Radiometer is supposed to be the first
radiometer made specifically for LED curing lights.
However, our tests show it not only measures the lights
for which it is intended, but also halogen. It is an exact
clone of its older sibling (Optilux Radiometer) in form
and usage, except for the color (it’s blue rather than
off-white) and the analog gauge, which is white with
black print (rather than the reverse), reads in mW/cm2
from 0-2000 in 200mW/cm2 increments (instead of 01000 in 100mW/cm2 increments). Therefore, since it
seems to do everything better than its elder and costs
exactly the same, this would seem to be the product to
buy if you don’t already have a light meter. On the
other hand, since you really don’t need to know if your
light is performing at levels above 1000mW/cm2, it is
712
The Ratings
not necessary to buy this meter if you already have the
original, since they both seem to register a similar output, regardless of what type of light you are checking.
As a matter of fact, the back of this light clearly states
that it detects blue light from 400-500 nanometers.
This explicitly means it will read any device producing
blue light, regardless of how it is produced.
In addition, even though it will read output as high
as 2000mW/cm2, the actual analog gauge is not any
wider. This means that each reading is less precise,
especially in the more critical lower ranges. It could
also be improved with a digital version that held its
reading once the light was deactivated. And the
recessed aperture, while helping to stabilize tips, also
makes it more difficult to clean.
©2005 REALITY Publishing Co. Vol. 19
Light Meters
The Optilux Radiometer has not changed and,
although the introduction of its blue sibling seems to
usurp its preeminent position, it still has great utility,
especially in measuring the critical lower power output
ranges. Its ease of use set the gold standard and it
shares the least expensive mantel with its family member. All you do is put your tip over its aperture, turn the
light on, and read the score. However, the analog
gauge on the Optilux Radiometer does not permit as
precise readings as digital readouts and it doesn’t hold
the reading when the light goes off.
The Cure Rite has a digital readout that is easier to
read and more precise than analog and it holds the
reading on the display for a few moments. However, to
use it again, you must turn it off and turn it on again.
It’s also the most expensive in this category. And,
although it is supposed to register output as high as
2000mW/cm2, we found it quickly lost a reading that
was close to its maximum.
OTHER PRODUCTS IN THIS CATEGORY
Coltolux Light Meter
Coltene/Whaledent
©2005 REALITY Publishing Co. Vol. 19
Curing Light Meter
Sullivan-Schein
The Ratings
713
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