Dental Curing Lights

What is the visible light spectrum normally and what is it for most composite?
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Terms in this set (27)
What is the visible light spectrum normally and what is it for most composite?
400-700nm

most composite: 400-520 (blue)
What does the resin have?
Photoinitator resin
absorbs photon energy,

combines with activator
creates free radicles
initiates polymerization
Image: What does the resin have?
# of photons per second emitted by light source
Flux
Image: # of photons per second emitted by light source
# of photons per second emitted by light source per unit area of curing tip
Irradiance
Image: # of photons per second emitted by light source per unit area of curing tip
Flux x time
Jule
Energy
Image: Flux x time Jule
Irradiance x time
Energy density
Image: Irradiance x time
Most common photo absorbing material

maximum sensitivity
blue range (470 nm)
Camphorquinone
Image: Most common photo absorbing material maximum sensitivity blue range (470 nm)
Most common dental curing light
encasing structure
heat resistant

tungsten
filament coil
flow of electricity
Quartz tungsten halogen
Image: Most common dental curing light encasing structure heat resistant tungsten filament coil flow of electricity
Cooling is critical in quartz tungsten halogen bc
Do not turn off fan
halogen gas lost
oxygen enters
bulb life dramatically decreases
Image: Cooling is critical in quartz tungsten halogen bc
Silver reflective surface
dissipates IR energy heat
reflects visible light
provides focal spot
Quartz tungsten halogen

reflectors
High levels of IR and UV extensive filtering remote light sourcePlasma archHigh irradiance > 2000 mW/cm claim 1-3 sec curePAC PS shrinkageA LED bulb produces light by passing the electric current through a semiconducting material -the diode0 which emits photonsLEDNarrow emission spectrum peak at 470 efficienctLEDT/F led have a long lasting light source with minimal aging and minimal decrease in outputTrueLess lateral heat production minimal or no fan necessary no filters typically cordlessLED curing lightsincreased depth of cure increased conversion (polymerization) increased hardnessThese are effects of increased light exposureDepends on energy density irradiance of light x time distance from composite collimation of light wavelengths emitted absorbed composite type.How long it takes to adequately cure a compositeVaries from composite to composite based on 2mm depth based On minimum 80% hardness ratio required energy density is not provided by most composite manufacturers!Optimal polymerizationPower incident upon an area surface area of the light guide large tips : lower ____ smaller tips: larger ____IrradianceIncreased irradiance ___ time decreased irradiance ___ timeDecrease increasedIs light whose rays are parallel. This light spreads slowly as it travels. ___ occurs when the rays in light line up with each other. Perfectly ___ light would not spread out with distance at allCollimation of light the greater the distance, the more energy you loseTurbo tapered tip :Increase radiance at tip but may decrease irradiance over distanceFor the best collimation you do not want /Microfills- scatter light darker shades- impede energy glass fillers are good though! Hybrids> flow alesHow long should i cure my composite?Cross linking relatively limited flows fairly easily Accomodates stresses no damage to adhesive bondEarly polymerizationFlow decreases stiffness increases stress increases can cause adhesion failure bond strength must exceed contraction stress stable marginal adaptationFurther polymerization n