60. Resistencia vs Poder de Salida
Muy poco poder Mucho poder
Curado incompleto Polimeros cortos
Restauración débil Mas fragil
Resistencia en tension
Poder ideal
Curado Completo
Restauracion fuerte
Densidad de Poder
104. Potential Retinal Hazards of Visible-light Photopolymerization Units
K. D. SATROM1, M. A. MORRIS2, and L. P. CRIGGER3
Dental Investigation Service, USAF School of Aerospace Medicine, Brooks AFB, Texas 78235; 2Department of Ophthalmology, UT Health Science
Center at San Antonio, San Antonio, Texas 78284; and 3USAF Dental Clinic Ramstein, Ramstein AFB, West Germany, APO, New York 09012-
5431
We evaluated the potential for retinal damage, both thermal and pho- mor, lens, and vitreous body) to the retina and can be asso-
tochemical, from commercially available visible-light photopolymer- ciated with three types of retinal damage (Ham, 1983): Structural
ization units. The spectral radiance profiles of 11 visible-light damage is caused by sonic transients and is associated only
photopolymerization units were measured by means of a spectrora- with mode-locked or Q-switched lasers; the other two types of
diometer and the results weighted according to the American Confer-
ence of Governmental Industrial Hygienists (ACGIH) Blue Light Hazard
damage are thermal and photochemical and can be caused by
Function and Thermal Hazard Function. The values were then inte- any high-intensity light source. Thermal damage results from
grated by means of the proposed ACGIH hazardformulae, so that we exposure to light sources of power levels and duration suffi-
could determine the maximum permissible exposure (tMAX) duration cient to raise the retinal temperature 100C or more above am-
for each light. This calculation assumed a worst-case condition of bient. Photochemical damage results from short wavelength
direct vision of the light source from a distance of 25 cm. The results light at power levels below that required for thermal damage
indicate that there is no thermal hazard to the retina. The tMAX du- (Ham et al., 1979).
ration values for the photochemical (blue light) hazard to the retina The purpose of this study was to evaluate the potential for
rangedfrom 2.4 minutes per day (for the most hazardous unit) to 16.0 retinal damage from commercially available visible-light pho-
minutes per day (for the least hazardous). None of these hazard times
is short enough to be of concern unless the individual operator elects topolymerization units.
to focus on the light source or the reflected output from these visible-
light photopolymerization units for an extended period of time.
Materials and methods.
J Dent Res 66(3):731-736, March, 1987 Visible-light photopolymerization units from 11 manufac-
turers were evaluated (see Table 1). For all units with a vari-
able intensity control, measurements were made at the highest
Introduction. intensity setting. A Pritchard 1980b Spectroradiometer (Photo
Research Division, Kollmorgen, Burbank, CA) was used to
Recently, several articles have mentioned the potential for ret- measure spectral radiance from 370 nm to 730 nm, in 10-nm
inal damage from the light emitted by visible-light photopoly- increments. For infra-red measurements, a black detector cal-
merization units (Pollack and Lewis, 1981; Benedetto and orimeter, consisting of a black detector thermocouple con-
Antonson, 1984; Council on Dental Materials, Instruments and nected to a Keithley 148 nanovoltmeter (Keithley Instruments,
Equipment, 1985 and 1986; Ellingson et al., 1986). Visible- Inc., Cleveland, OH), was used to measure the energy output
light-cured resins are an outgrowth of the ultraviolet (UV) light- of the light. Measurements were made without filters between
cured resins and are single-paste systems possessing photo- the light and detector, and then with a Schott KG-3 infra-red
initiators that absorb light in the 420-to-450-nanometer (nm) blocking glass filter (Schott Optical Glass, Duryea, PA), which
range. Polymerization is induced by the production of free blocks virtually all light below 300 nm and above 700 nm and
radicals. The visible-light photopolymerization units designed transmits approximately 80% of the visible light from 300 nm
to initiate polymerization are high-intensity light sources with to 700 nm. A Ralph Gerbands Co. shutter (Ralph Gerbands
outputs concentrated in the 400-to-550-nm region (primarily Co., Arlington, MA) was used on the light to control exposure
the blue portion) of the visible spectrum. duration. Several measurements were made for each condition.
Light within the spectral range of from 400 nm to 1400 nm Using these data, we calculated the integrated infra-red ra-
is transmitted through the ocular media (cornea, aqueous hu- diance in the following manner: The energy measured without
the KG-3 filter equals the sum of all visible and infra-red
energy. The energy measured with the filter is 80% (the mean
Received for publication May 14, 1986 visible transmittance) of the total energy minus all the light
Accepted for publication October 17, 1986 energy above 700 nm, since this is the - 3 db cut-off point of
'Present address: 7338 Walling Lane, Dallas, TX 75231
Address reprint requests to the USAF Dental Investigation Service,
the filter. The ratio of infra-red to visible energy can thus be
USAF SAM/NGD, Brooks AFB, Texas 78235. calculated. If r is the ratio of filtered light energy to unfiltered
This report was prepared as an account of work sponsored by an light energy, then the ratio of infra-red to visible energy is:
agency of the United States Government. Neither the United States 0.8 - r
Government nor any agency thereof, nor any of their employees, nor k=
any of their contractors, subcontractors, or their employees, makes r
any warranty, expressed or implied, or assumes any legal liability or
responsibility for the accuracy, completeness, or usefulness of any The integrated visible radiance was determined by use of the
information, apparatus, product, or process disclosed, or represents results of the spectroradiometric measurements from 370 to
that its use would not infringe privately owned rights. Reference herein
to any specific commercial product, process, or service by trade name,
700 nm. Multiplying this by k yields the total integrated infra-
trademark, manufacturer, or otherwise, does not necessarily constitute red radiance. This result was used for hazard calculations re-
or imply its endorsement, recommendation, or favoring by the United quiring infra-red measurements, assuming a mean weighting
States Government or any agency, contractor, or subcontractor thereof. factor of 0.5. The spectral radiance profiles of each light were
The views and opinions of authors expressed herein do not necessarily weighted according to the potential of its component wave-
state or reflect those of the United States Government or any agency, lengths to produce retinal damage, by use of the American
contractor, or subcontractor thereof. Conference of Governmental Industrial Hygienists (ACGIH)
Downloaded from http://jdr.sagepub.com by David Lafuente on June 10, 2009 731
105. Potential Retinal Hazards of Visible-light Photopolymerization Units
K. D. SATROM1, M. A. MORRIS2, and L. P. CRIGGER3
Dental Investigation Service, USAF School of Aerospace Medicine, Brooks AFB, Texas 78235; 2Department of Ophthalmology, UT Health Science
Center at San Antonio, San Antonio, Texas 78284; and 3USAF Dental Clinic Ramstein, Ramstein AFB, West Germany, APO, New York 09012-
5431
We evaluated the potential for retinal damage, both thermal and pho- mor, lens, and vitreous body) to the retina and can be asso-
tochemical, from commercially available visible-light photopolymer- ciated with three types of retinal damage (Ham, 1983): Structural
ization units. The spectral radiance profiles of 11 visible-light damage is caused by sonic transients and is associated only
photopolymerization units were measured by means of a spectrora- with mode-locked or Q-switched lasers; the other two types of
diometer and the results weighted according to the American Confer-
ence of Governmental Industrial Hygienists (ACGIH) Blue Light Hazard
damage are thermal and photochemical and can be caused by
Function and Thermal Hazard Function. The values were then inte- any high-intensity light source. Thermal damage results from
grated by means of the proposed ACGIH hazardformulae, so that we exposure to light sources of power levels and duration suffi-
could determine the maximum permissible exposure (tMAX) duration cient to raise the retinal temperature 100C or more above am-
for each light. This calculation assumed a worst-case condition of bient. Photochemical damage results from short wavelength
direct vision of the light source from a distance of 25 cm. The results light at power levels below that required for thermal damage
indicate that there is no thermal hazard to the retina. The tMAX du- (Ham et al., 1979).
ration values for the photochemical (blue light) hazard to the retina The purpose of this study was to evaluate the potential for
rangedfrom 2.4 minutes per day (for the most hazardous unit) to 16.0 retinal damage from commercially available visible-light pho-
minutes per day (for the least hazardous). None of these hazard times
is short enough to be of concern unless the individual operator elects topolymerization units.
to focus on the light source or the reflected output from these visible-
light photopolymerization units for an extended period of time.
Materials and methods.
J Dent Res 66(3):731-736, March, 1987 Visible-light photopolymerization units from 11 manufac-
turers were evaluated (see Table 1). For all units with a vari-
able intensity control, measurements were made at the highest
Introduction. intensity setting. A Pritchard 1980b Spectroradiometer (Photo
Research Division, Kollmorgen, Burbank, CA) was used to
Recently, several articles have mentioned the potential for ret- measure spectral radiance from 370 nm to 730 nm, in 10-nm
inal damage from the light emitted by visible-light photopoly- increments. For infra-red measurements, a black detector cal-
merization units (Pollack and Lewis, 1981; Benedetto and orimeter, consisting of a black detector thermocouple con-
Antonson, 1984; Council on Dental Materials, Instruments and nected to a Keithley 148 nanovoltmeter (Keithley Instruments,
Equipment, 1985 and 1986; Ellingson et al., 1986). Visible- Inc., Cleveland, OH), was used to measure the energy output
light-cured resins are an outgrowth of the ultraviolet (UV) light- of the light. Measurements were made without filters between
cured resins and are single-paste systems possessing photo- the light and detector, and then with a Schott KG-3 infra-red
initiators that absorb light in the 420-to-450-nanometer (nm) blocking glass filter (Schott Optical Glass, Duryea, PA), which
range. Polymerization is induced by the production of free blocks virtually all light below 300 nm and above 700 nm and
radicals. The visible-light photopolymerization units designed transmits approximately 80% of the visible light from 300 nm
to initiate polymerization are high-intensity light sources with to 700 nm. A Ralph Gerbands Co. shutter (Ralph Gerbands
outputs concentrated in the 400-to-550-nm region (primarily Co., Arlington, MA) was used on the light to control exposure
the blue portion) of the visible spectrum. duration. Several measurements were made for each condition.
Light within the spectral range of from 400 nm to 1400 nm Using these data, we calculated the integrated infra-red ra-
is transmitted through the ocular media (cornea, aqueous hu- diance in the following manner: The energy measured without
the KG-3 filter equals the sum of all visible and infra-red
energy. The energy measured with the filter is 80% (the mean
Received for publication May 14, 1986 visible transmittance) of the total energy minus all the light
Accepted for publication October 17, 1986 energy above 700 nm, since this is the - 3 db cut-off point of
'Present address: 7338 Walling Lane, Dallas, TX 75231
Address reprint requests to the USAF Dental Investigation Service,
the filter. The ratio of infra-red to visible energy can thus be
USAF SAM/NGD, Brooks AFB, Texas 78235. calculated. If r is the ratio of filtered light energy to unfiltered
This report was prepared as an account of work sponsored by an light energy, then the ratio of infra-red to visible energy is:
agency of the United States Government. Neither the United States 0.8 - r
Government nor any agency thereof, nor any of their employees, nor k=
any of their contractors, subcontractors, or their employees, makes r
any warranty, expressed or implied, or assumes any legal liability or
responsibility for the accuracy, completeness, or usefulness of any The integrated visible radiance was determined by use of the
information, apparatus, product, or process disclosed, or represents results of the spectroradiometric measurements from 370 to
that its use would not infringe privately owned rights. Reference herein
to any specific commercial product, process, or service by trade name,
700 nm. Multiplying this by k yields the total integrated infra-
trademark, manufacturer, or otherwise, does not necessarily constitute red radiance. This result was used for hazard calculations re-
or imply its endorsement, recommendation, or favoring by the United quiring infra-red measurements, assuming a mean weighting
States Government or any agency, contractor, or subcontractor thereof. factor of 0.5. The spectral radiance profiles of each light were
The views and opinions of authors expressed herein do not necessarily weighted according to the potential of its component wave-
state or reflect those of the United States Government or any agency, lengths to produce retinal damage, by use of the American
contractor, or subcontractor thereof. Conference of Governmental Industrial Hygienists (ACGIH)
Downloaded from http://jdr.sagepub.com by David Lafuente on June 10, 2009 731
106. ence of Governmental Industrial Hygienists (ACGIH) Blue Light Hazard
Thermal Hazard Photopolymerization The
Function andPotential Retinal Hazards of Visible-light Function. Units values were then inte-
grated by means of the proposed ACGIH hazardformulae, so that we
K. D. SATROM1, M. A. MORRIS2, and L. P. CRIGGER3
could determine the maximum permissible exposure (tMAX) duration
Dental Investigation Service, USAF School of Aerospace Medicine, Brooks AFB, Texas 78235; 2Department of Ophthalmology, UT Health Science
Center at San Antonio, San Antonio, Texas 78284; and 3USAF Dental Clinic Ramstein, Ramstein AFB, West Germany, APO, New York 09012-
5431
for each light. This calculation assumed a worst-case condition of
We evaluated the potential for retinal damage, both thermal and pho-
tochemical, from commercially available visible-light photopolymer-
mor, lens, and vitreous body) to the retina and can be asso-
ciated with three types of retinal damage (Ham, 1983): Structural
direct vision of the light source from a distance of 25 cm. The results
ization units. The spectral radiance profiles of 11 visible-light
photopolymerization units were measured by means of a spectrora-
diometer and the results weighted according to the American Confer-
ence of Governmental Industrial Hygienists (ACGIH) Blue Light Hazard
damage is caused by sonic transients and is associated only
with mode-locked or Q-switched lasers; the other two types of
damage are thermal and photochemical and can be caused by
indicate that there is no thermal hazard to the retina. The tMAX du-
Function and Thermal Hazard Function. The values were then inte-
grated by means of the proposed ACGIH hazardformulae, so that we
could determine the maximum permissible exposure (tMAX) duration
any high-intensity light source. Thermal damage results from
exposure to light sources of power levels and duration suffi-
cient to raise the retinal temperature 100C or more above am-
ration values for the photochemical (blue light) hazard to the retina
for each light. This calculation assumed a worst-case condition of bient. Photochemical damage results from short wavelength
direct vision of the light source from a distance of 25 cm. The results light at power levels below that required for thermal damage
indicate that there is no thermal hazard to the retina. The tMAX du- (Ham et al., 1979).
ration values for the photochemical (blue light) hazard to the retina The purpose of this study was to evaluate the potential for
rangedfrom 2.4 minutes per day (for the most hazardous unit) to 16.0
rangedfrom 2.4 minutes per day (for the most hazardous unit) to 16.0
minutes per day (for the least hazardous). None of these hazard times
is short enough to be of concern unless the individual operator elects
to focus on the light source or the reflected output from these visible-
retinal damage from commercially available visible-light pho-
topolymerization units.
minutes per day (for the least hazardous). None of these hazard times
light photopolymerization units for an extended period of time.
Materials and methods.
J Dent Res 66(3):731-736, March, 1987 Visible-light photopolymerization units from 11 manufac-
turers were evaluated (see Table 1). For all units with a vari-
is short enough to be of concern unless the individual operator elects
Introduction.
able intensity control, measurements were made at the highest
intensity setting. A Pritchard 1980b Spectroradiometer (Photo
Research Division, Kollmorgen, Burbank, CA) was used to
to focus on the light source or the reflected output from these visible-
Recently, several articles have mentioned the potential for ret- measure spectral radiance from 370 nm to 730 nm, in 10-nm
inal damage from the light emitted by visible-light photopoly- increments. For infra-red measurements, a black detector cal-
merization units (Pollack and Lewis, 1981; Benedetto and orimeter, consisting of a black detector thermocouple con-
Antonson, 1984; Council on Dental Materials, Instruments and nected to a Keithley 148 nanovoltmeter (Keithley Instruments,
light photopolymerization units for an extended period of time.
Equipment, 1985 and 1986; Ellingson et al., 1986). Visible-
light-cured resins are an outgrowth of the ultraviolet (UV) light-
cured resins and are single-paste systems possessing photo-
Inc., Cleveland, OH), was used to measure the energy output
of the light. Measurements were made without filters between
the light and detector, and then with a Schott KG-3 infra-red
initiators that absorb light in the 420-to-450-nanometer (nm) blocking glass filter (Schott Optical Glass, Duryea, PA), which
range. Polymerization is induced by the production of free blocks virtually all light below 300 nm and above 700 nm and
radicals. The visible-light photopolymerization units designed transmits approximately 80% of the visible light from 300 nm
to initiate polymerization are high-intensity light sources with to 700 nm. A Ralph Gerbands Co. shutter (Ralph Gerbands
outputs concentrated in the 400-to-550-nm region (primarily Co., Arlington, MA) was used on the light to control exposure
J Dent Res 66(3):731-736, March, 1987
the blue portion) of the visible spectrum.
Light within the spectral range of from 400 nm to 1400 nm
is transmitted through the ocular media (cornea, aqueous hu-
duration. Several measurements were made for each condition.
Using these data, we calculated the integrated infra-red ra-
diance in the following manner: The energy measured without
the KG-3 filter equals the sum of all visible and infra-red
energy. The energy measured with the filter is 80% (the mean
Received for publication May 14, 1986 visible transmittance) of the total energy minus all the light
Accepted for publication October 17, 1986 energy above 700 nm, since this is the - 3 db cut-off point of
'Present address: 7338 Walling Lane, Dallas, TX 75231
Address reprint requests to the USAF Dental Investigation Service,
the filter. The ratio of infra-red to visible energy can thus be
Introduction. USAF SAM/NGD, Brooks AFB, Texas 78235. calculated. If r is the ratio of filtered light energy to unfiltered
This report was prepared as an account of work sponsored by an light energy, then the ratio of infra-red to visible energy is:
agency of the United States Government. Neither the United States 0.8 - r
Government nor any agency thereof, nor any of their employees, nor k=
any of their contractors, subcontractors, or their employees, makes r
any warranty, expressed or implied, or assumes any legal liability or
responsibility for the accuracy, completeness, or usefulness of any The integrated visible radiance was determined by use of the
information, apparatus, product, or process disclosed, or represents results of the spectroradiometric measurements from 370 to
that its use would not infringe privately owned rights. Reference herein
to any specific commercial product, process, or service by trade name,
700 nm. Multiplying this by k yields the total integrated infra-
red radiance. This result was used for hazard calculations re-
Recently, several articles have mentioned the potential for ret-
trademark, manufacturer, or otherwise, does not necessarily constitute
or imply its endorsement, recommendation, or favoring by the United quiring infra-red measurements, assuming a mean weighting
States Government or any agency, contractor, or subcontractor thereof. factor of 0.5. The spectral radiance profiles of each light were
The views and opinions of authors expressed herein do not necessarily weighted according to the potential of its component wave-
state or reflect those of the United States Government or any agency, lengths to produce retinal damage, by use of the American
inal damage from the light emitted by visible-light photopoly-
contractor, or subcontractor thereof. Conference of Governmental Industrial Hygienists (ACGIH)
Downloaded from http://jdr.sagepub.com by David Lafuente on June 10, 2009 731