DENTSPLY DeTrey SmartLite PS User manual

Table of contents
1Introduction ................................................................................. 3
2SmartLite PS Design ................................................................... 3
2.1 LED-Tip ..........................................................................................................3
2.2 Hand piece.....................................................................................................4
2.3 Charger ..........................................................................................................4
3Intensity and Spectral Output .................................................... 4
4Light output stability................................................................... 6
5Thermal radiation ........................................................................ 7
5.1 In-vitro tooth heating study..........................................................................7
5.2 Temperature of the LED Tip .........................................................................8
6Curing performance .................................................................... 9
6.1 Depth of Cure according to ISO 4049:2000 ................................................9
6.2 Barcol hardness..........................................................................................10
6.3 Compressive strength ................................................................................11
7Clinical data ............................................................................... 12
7.1 Consumer preference evaluation ..............................................................12
7.2 Clinical post-marketing surveillance study, Republic of South Africa ..14
8Conclusion................................................................................. 16
9Indications, contra-indications, warnings, and precautions . 16
10 Directions for use...................................................................... 18
10.1 Installation and charging ...........................................................................18
10.2 Operation.....................................................................................................19
10.3 Maintenance ................................................................................................20
11 Guarantee terms........................................................................ 21
12 Specifications ............................................................................ 22
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SmartLite™ PS Scientific Compendium
1 Introduction
Unlike conventional halogen lamps, light emitting diodes (LED) produce light in the visible
range of the electromagnetic spectrum via quantum mechanical effects using doped
semiconductors. LED lamps emit highly efficient light in a limited wavelength range. The LED
needs less power than a halogen light bulb, in which the light is generated by heating a
tungsten filament in the presence of a halogen gas.
Due to the fact that the emission spectrum of the blue LED closely matches the absorbance
peak of camphorquinone - the most commonly used photo initiator in visible light cured
dental materials -, the LED units represent a considerable improvement over halogen lamps
due to the improved conversion efficiency and longer LED life time.
Thus, this technology is an ideal basis for cordless devices improving the convenience of the
curing procedure in the dental surgery. Noisy and uncomfortable cooling fans, necessary in
traditional Quartz-Tungsten-Halogen (QTH) curing lights, are not needed due to the higher
efficiency of LEDs.
SmartLite PS is an LED curing light that is small and easy to use, yet powerful and swift in
curing. The following information will provide details on the curing performance and
demonstrate the high efficiency and safety of this new curing device. Properties that make it
ideal as replacement of traditional QTH curing units.
2 SmartLite PS Design
2.1 LED-Tip
The black anodized aluminium tip of the SmartLite PS comprises a grip, enabling the
operator to rotate the tip in an easy manner. Furthermore, an easy orientation of the LED-tip
is given even in situations of low brightness and limited space by a crosshair on the backside
of the tip, indicating the direction of the light.
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SmartLite™ PS Scientific Compendium
2.2 Hand piece
Due to the compact design of the hand piece the SmartLite PS is very easy and precise to
handle. Pressing the ON/OFF button activates the 10-sec standard cure. Several visual and
acoustic signals give the operator information on the battery status and/or if the LED-tip is
not properly connected to the hand piece.
The hand piece comprises a rechargeable Nickel-Metal-Hydride (NiMH) battery, which
provides a minimum of 150 curing cycles at 10 seconds with a stable power output even at a
low battery charging status. This is achieved by means of a microprocessor-controlled
technology.
2.3 Charger
Four charger types are available adjusted to the specific plugs and voltage of the respective
countries:
EU-plug: 220 – 240 V
UK-plug: 220 – 240 V
US-plug: 110 – 130 V
Japan-plug: 90 – 110 V
3 Intensity and Spectral Output
By using the Cure Rite™ photometer the intensity of a standardised area is measured and
directly indicated for all lamps.
The SmartLite PS has a powerful 5W LED with an average light output of more than 950
mW/cm2. This value is comparable to most other LED lights and some more powerful
halogen lights (Figure 1).
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SmartLite™ PS Scientific Compendium
0 250 500 750 1000 1250
Light intensity [mW/cm2]
SmartLite PS
Epilar FreeLight 2
Starlight Pro
L.E.Demetron I *
Spectrum800@800
Light intensity determined with CureRite
Figure 1 Light intensity of SmartLite PS compared to other curing lights
The SmartLite PS does not - unlike the widely used Quartz-Tungsten-Halogen (QTH) lamp -
emit light with wavelengths beyond the absorbance range of camphorchinone (CQ). CQ is
the most commonly used photo initiator in almost all visible light cured dental materials. Thus
the light emitted by the SmartLite PS corresponds to the absorbance maximum of CQ, which
ensures a very efficient activation and curing of the restorative material (Figure 2).
350 400 450 500 550
Wavelength [nm]
SmartLite PS
QTH light
Absorbance CQ
Figure 2 Emission spectrum of the SmartLite PS and of a QTH light compared to the
absorbance spectrum of CQ
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SmartLite™ PS Scientific Compendium
4 Light output stability
It is well known from conventional halogen lights (QTH) that the curing performance is
strongly dependent on the bulb. Towards the end of the bulb’s lifetime the output is seen to
drop dramatically. As this can not be checked automatically, it is of outmost importance to
test the QTH curing lamp on a regular basis in order to detect any deterioration in its curing
performance. The LED technology offers the advantage that the LED light source does not
deteriorate over the life time of approximately 10.0000 hours and therefore does not require
maintenance or constant monitoring.
As shown in Figure 3, a fully charged battery provides approx. 150 ten-second cures
(approx. 25 minutes operating time) with constant light output. Therefore, under most
conditions of use, the device only needs to be recharged over night.
When the battery light flashes red (fast), the battery needs to be recharged. Another
2 minutes exposure time is then left for completion of the treatment. Light output is not
reduced during this period. After these 2 minutes, the device switches off automatically and
continues to flash red (slowly) indicating the need to recharge.
600
800
1000
1200
0 20 40 60 80 100 120 140 160 180
Number of 10sec cures
Light output [mW/cm2]
Figure 3 Light output upon repeated cycles.
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SmartLite™ PS Scientific Compendium
5 Thermal radiation
Besides the emission of visible light in the spectral range of approximately 400-500 nm all
curing lamps radiate heat as well. The amount of heat that is radiated towards the tooth
depends on the output power and the exposure time. A balance between high light power
and low heat irradiation is needed to avoid the risk that heat may have on the pulp tissue and
the oral mucosa.
5.1 In-vitro tooth heating study
A tooth heating study was conducted at the Department of Oral Rehabilitation, Medical
College of Georgia (head: Professor F. Rueggeberg, DDS, MS). The purpose of this
investigation was to simulate and determine in vitro the intra-pulpal temperature rise in a
model using extracted human bicuspids (Figure 4) comparing the SmartLite PS to a variety
of commercial light-curing units (Figure 5).
Light tip
water outlet
thermocouple leads
to cold junction
compensator
Inlet for
temperature-controlled water
from infusion pump
thermocouple
j
unction
1 mm
0.75 - 1 mm
Tooth roots
immersed in a
thermostatically
controlled water bath
Figure 4 In-vitro simulation of light curing and measurement of intra-pulpal temperature
rise (Rueggeberg)
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SmartLite™ PS Scientific Compendium
012345
TEMPERATURE (°C)
STARLIGHT Pro
SmartLite PS
Optilux 501
LEDemetron I
Spectrum 800@800
FreeLight 2
CURING CONDITION
PEAK INTRAPULPAL TEMPERATURE RISE
SIMULATING A 10 SEC CURE
012345
TEMPERATURE (°C)
STARLIGHT Pro
SmartLite PS
Optilux 501
LEDemetron I
Spectrum 800@800
FreeLight 2
CURING CONDITION
PEAK INTRAPULPAL TEMPERATURE RISE
SIMULATING A 10 SEC CURE
PEAK INTRAPULPAL TEMPERATURE RISE
SIMULATING A 10 SEC CURE
Elipar Freelight 2
Spectrum 800
L. E. Demetron 1
Figure 5 Intra-pulpal temperature rise after 10s exposure with various curing units
The temperature rise after a 10sec exposure using the SmartLite PS ranged from 2.4 to
2.8° C and was significantly lower than of the following commercially available LED and
halogen units: L. E. Demetron 1, Elipar FreeLight 2, Optilux 501, and Spectrum800.
Moreover, longer exposure times have shown that the SmartLite PS emits and transfers less
heat onto the tooth than other widely used LED and halogen curing lights.
5.2 Temperature of the LED Tip
ISO 60601 requires that equipment parts that may have a brief contact with a patient must
not be warmer than 50 °C. If SmartLite PS is used according to the directions for use, which
request a waiting period of 30 seconds between 10-second curing cycles, the device is in
compliance with the above-mentioned standard.
If, in deviation from the directions for use, the device is used with shorter waiting periods or
for longer curing cycles, the temperature of the LED Tip may rise above 50 °C. However,
experiments for curing cycles up to 30 seconds long have shown that, if typical direct
restorative procedures are simulated, the resulting temperatures do not create any hazard
regarding tissue compatibility and do not negatively affect the lifespan of the LED light. Still,
SmartLite PS must not be used for the luting of indirect restorations as this process is
associated with many consecutive and long curing cycles.
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SmartLite™ PS Scientific Compendium
6 Curing performance
6.1 Depth of Cure according to ISO 4049:2000
The depth of cure of a restorative material correlates directly with the light output of a curing
light. The higher the intensity of a curing light the more efficient the depth of cure. This
usually is the result of a higher degree of conversion, which leads to a stronger material and
an increase in durability of the resulting restoration.
Depth of cure was measured for SmartLite PS, along with other LED lights, and a strong
halogen light according to the method described in the ISO 4049:2000.
It is important to note that this particular method defines the depth of cure as 50 % of the
actual thickness of the cured cylindrical specimen: A sample of the material is exposed to the
light source and the un-polymerised material is scraped away using a spatula. The thickness
of the remaining sample is then divided by 2 resulting in the depth of cure according to ISO.
The results are shown in Figure 6 and Figure 7.
0,0
0,5
1,0
1,5
2,0
2,5
3,0
SmartLite PS Starlight Pro L.E.Demetron I Spectrum 800
@800
Depth of Cure [mm]
Figure 6 Depth of Cure (ISO 4049:2000) of Spectrum TPH A2 after a 10sec cure with
various curing units
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SmartLite™ PS Scientific Compendium
0,0
0,5
1,0
1,5
2,0
2,5
Depth of Cure [mm]
SmartLite PS Starlight Pro L.E.Demetron I Spectrum 800
@800
Figure 7 Depth of Cure (ISO 4049:2000) of Spectrum TPH A4 after a 10sec cure with
various curing units
The above data demonstrate that even for dark shades such as SpectrumTPHA4 a depth of
cure of 2mm thickness can be achieved with SmartLite PS after 10sec exposure .
6.2 Barcol hardness
Another method to determine the curing performance of a curing light is to measure the
hardness of the exposed surface and the hardness at a given depth using Barcol hardness.
By curing a 2mm thick sample of the restorative material (Spectrum TPH A2, A4) the
obtained hardness values for the illuminated (top) and the non-illuminated (bottom) side of
the sample, as well as the bottom/top hardness ratio, were measured. The results
demonstrate again that a 2 mm depth of cure can be achieved by using SmartLite PS for
10 seconds (Figure 8, Figure 9).
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