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Light Curing Devices.3521

Jun 03, 2018

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Piyush Mittal
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    Light Curing Devices

    1. QTH LAMPS

    2. ARGON LASER LAMPS

    3. PAC LAMPS

    4. LED LAMPS

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    Quartz-Tungsten-Halogen

    Most common dental curing light

    Quartz

    Encasing structureCrystalline

    Heat resistant

    Tungsten

    Filament coil

    Flow of electricity

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    Quartz-Tungsten-Halogen

    Halogen gasProtects filament from

    oxidation

    Re-deposits tungstento filament halogen cycle

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    Quartz-Tungsten-Halogen

    Radiant output

    infrared energy (IR)

    heatCooling critical

    Do not turn off fan

    Halogen gas lost

    Oxygen enters

    Bulb life dramatically decreases

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    Quartz-Tungsten-Halogen

    Filters

    restricts broader light

    to narrow blue light400-500 nm

    range of photo-initiators

    99.5% of original radiant energyfiltered

    inefficient

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    ARGON LASER

    Introduced in 1964

    Produces a wavelength of 488nm

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    Argon Laser

    High energy

    coherent, non-divergentVery expensive

    Warning signs required

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    PAC Devices

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    Plasma-Arc (PAC)

    Two tungsten electrodes

    small gap

    Pressurized chamber

    xenon gas

    High-voltage spark ionizes gas

    plasma

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    Plasma-Arc (PAC)

    High levels of IR and UV

    extensive filteringdown to 400-500 nm

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    Plasma-Arc (PAC)

    High irradiance

    > 2000 mW/cm2

    claim 1-3 sec cure

    Expensive

    Less Depth of Cure

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    Light emitting diode

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    Light-Emitting Diodes (LED)

    Semiconductors

    electrically-excited atoms

    Gallium-nitride blueGallium - Arsenide

    Narrow emission spectrum

    430-490 nm

    peak at 470 nm

    efficient

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    LED Curing Lights

    Long lasting light source

    minimal ageing

    minimal decrease in output Less lateral heat production

    minimal or no fan

    necessary No filters

    Typically cordless

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    LED Curing Lights

    First generation

    high cost

    low irradiance

    < 300 mW/cm2

    increase exposure time

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    LED Curing Lights

    Second generation

    lower cost

    higher irradiance

    > 600 mW/cm2

    similar to halogen

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    Depth of cure andExposure time

    Degree of conversion

    Opacity, filler size, filler

    concentration and pigment shadeof the composite resin.

    Absorption and scattering of light

    by tooth structure especially dentin.

    Quality and intensity of light sourceas well as age of light source.

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    Clinical Techniques

    Incremental build up

    cavity configuration

    Soft start

    ramped curing

    delayed curing

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    PRECAUTIONS FOR USINGCURING LAMPS

    The dentist and the patient mustwear protective glasses

    Curing light should be as close aspossible to composite

    Curing tip should be clean

    Use incremental technique only

    Irradiance should be checkedperiodically

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    hank You