Types of Light Curing Machine

Plasma Arc Curing Lamps (PAC)

Uses 2 TUNGSTEN ELECTRODES which are SURROUNDED BY A GAS (XENON).

Plasma Arc Curing Lamps (PAC)

The WHITE LIGHT that is of HIGH INTENSITY is FILTERED to REMOVE HEAT and to allow BLUE LIGHT (about 400 to 500nm) to be EMITTED.

Plasma Arc Curing Lamps (PAC)

Uses SPECIFIC LIGHT TIPS for particular situations REQUIRING DIFFERENT EMISSION SPECTRA.

Plasma Arc Curing Lamps (PAC)

In LATE 1990’s, this system has been introduced as a means of RAPID LIGHT CURING.

Camphorquinone

(PAC) A LIGHT GUIDE helps in FILTERING THE LIGHT TO SPECTRUM OF VISIBLE LIGHT (450-500 nm) for peak ABSORPTION of?

1800

PAC produces HIGH INTENSITY LIGHT more than ____ mW/cm2.

6-9 Seconds

CURING CYCLE in PAC is how many seconds (range).

Yes

Does PAC produce rapid polymerization?

Argon Laser

Considered to be a GOOD CHOICE for a HIGH IRRADIANCE CURING LIGHT UNIT because it could RAPIDLY CURE DENTAL RESINS.

Argon Laser

Have the HIGHEST INTENSITY and emit a SINGLE WAVELENGTH (490nm), also DOESN’T PRODUCE a BROAD SPECTRUM LIGHT but many INTENSE and WELL-DEFINED EMISSION PEAKS in the blue spectral region.

Dark

(Argon Laser) DEGREE OF POLYMERIZATION IS HIGHER WITH ____ SHADES as compared to conventional halogen lights.

Yes

Can argon laser affect adjacent restorations?

Quartz Tungsten Halogen (QTH)

Utilizes A BULB (QUARTZ) WITH A TUNGSTEN FILAMENT.

Quartz Tungsten Halogen (QTH)

It IRRADIATES BOTH THE UV AND WHITE LIGHT that is filtered to REMOVE HEAT and ALL WAVELENGTHS except the VIOLET-BLUE RANGE (about 400 to 500nm).

Quartz Tungsten Halogen (QTH)

It is an INCANDESCENT LAMP which uses VISIBLE LIGHT in the wavelength in the range of 410 to 500 nm.

Quartz Tungsten Halogen (QTH)

At the START OF THE CURING CYCLE, this light emits a LOW POWER DENSITY (400-900 mW/cm2).

5% - 2%

(QTH) Of the TOTAL ENERGY INPUT is emitted as USEFUL BLUE LIGHT.

10%

(QTH) VISIBLE LIGHT is produced.

70%

(QTH) CONVERTED INTO HEAT, making QTH curing light as INEFFICIENT.

Decreases

(QTH) Bulb intensity _________ with time.

Light Emitting Diode (LED)

The LED emits RADIATION only in the BLUE PART OF THE VISIBLE SPECTRUM (440-480nm).

No

Does LED require filters?

Light Emitting Diode (LED)

Very EFFICIENT at CONVERTING ELECTRICAL ENERGY to ELECTROMAGNETIC RADIATION.

Light Emitting Diode (LED)

These units usually have a LONG LIFE and emit POWERFUL BLUE LIGHT.

455 - 486

(LED) This light falls in a NARROW WAVELENGTH RANGE of ___ nm to ___ nm. This corresponds to the range of CAMPHORQUINONE PHOTOINITIATOR found in most COMPOSITE RESINS.

Light Emitting Diode (LED)

Only suitable for CAMPHORQUINONE BASED COMPOSITES (because it has limited wavelength spectrum).

First Generation

(LED Gen) Was called “COOL” LIGHTS, because it produced LESS HEAT, and LESS TEMPERATURE RISE in the PULP than the QTH light curing units.

First Generation

(LED Gen) The LOW HEAT GENERATION of this curing unit is due to their LOW RADIANT POWER OUTPUT (470nm).

First Generation - Second Generation

(LED Gen) This curing unit is INCOMPATIBLE with LUCIRIN and TPO (2).

Second Generation

(LED Gen) Uses new HIGH OUTPUT BLUE LED CHIPS, which resulted in a REDUCED recommended EXPOSURE TIME than QTH.

Second Generation

(LED Gen) An INTERNAL COOLING FAN and a LARGE METAL SINK were added to this curing unit, because the INCREASED RADIANT POWER OUTPUT also INCREASED HEAT OUTPUT.

Third Generation

(LED Gen) The light curing unit then can EMIT LIGHT OF MORE THAN ONE WAVELENGTH RANGE.

Third Generation

(LED Gen) This curing unit can ACTIVATE ALL THE PHOTOINITIATORS used for composite resins.

Electromagnetic

The RADIANT ENERGY perceived by HUMANS as “LIGHT” is _______________ RADIATION.

Photons

EM RADIATION is delivered in packages of energy called?

Wavelength

Dental terminology utilizes __________ (in nanometers) rather than the FREQUENCY (Hz) to describe the PROPERTIES OF LIGHT.

Photoinitiator

Compounds in the COMPOSITE RESIN that creates FREE RADICALS when exposed to UV, VISIBLE LIGHT, or RADIATION.

Photoinitiator

The ABILITY OF A ____________ TO INTERACT WITH ELECTROMAGNETIC ENERGY is dependent on the: FREQUENCY (wavelength) of the PHOTON and the VERY SPECIFIC ELECTRON CONFIGURATION of the PHOTOINITIATOR MOLECULE.

Type I

(Photoinitiator) Require FEWER PHOTONS to generate FREE RADICALS.

Type I

(Photoinitiator) Does not need CO-INITIATORS.

Type I

(Photoinitiator) Breakdown directly into ONE OR MORE FREE RADICALS after ABSORPTION OF LIGHT.

Type I

(Photoinitiator) Examples include lucerin, TPO, Ivocerin.

Type II

(Photoinitiator) Require an ADDITIONAL SECONDARY ELECTRON TRANSFER AGENT to create FREE RADICALS.

Type II

(Photoinitiator) Slower and LESS EFFICIENT.

Type II

(Photoinitiator) Examples include camphorquinone and phenly propopanedione.

Polymerized

When INSUFFICIENT LIGHT is delivered, the resin is INADEQUATELY ___________.

Depth of Cure

The boundary between what is considered the CURED and UNCURED RESIN is called the?

1.5-2 mm

Under OPTIMUM CONDITIONS for light curing, the depth of cure for conventional composite resin is?

4 mm - 6 mm

Under OPTIMUM CONDITIONS for light curing, the depth of cure for bulk fill composite is (2)?

Shade - Translucency

Conditions such as COMPOSITE ______ and ____________ will affect depth of cure.

1000

Under OPTIMAL CONDITIONS using a curing light that delivers ____ mW/cm2 from an 8- to 10-mm-diameter tip.

20

Many resin composites require a __ SECOND EXPOSURE TIME typically (delivering 20 J/cm2 ) to adequately cure a 2-mm-thick increment of resin.

Fewer

As the resin composite THICKNESS INCREASES, exponentially _____ PROTONS REACH TO THE BOTTOM.

0.5 - 1 mm

Resin thickness should be IDEALLY (range)?

Microfine

_________ composites are MORE DIFFICULT TO CURE than HEAVILY LOADED composites.

Smaller

LIGHT SCATTERING is GREATER when the FILLER PARTICLE SIZE is EQUAL TO OR ________ than the WAVELENGTH OF LIGHT.

Better - Better

The CLOSER the REFRACTIVE INDICES of the resin and the FILLER are MATCHED, the _______ will be the LIGHT TRANSMISSION through the RESIN COMPOSITE and the _______ THE DEPTH OF CURE.

Gray

If they are PERFECTLY MATCHED, the FILLER PARTICLES will OPTICALLY DISAPPEAR, but the INCREASED TRANSLUCENCY will mean that the RESIN COMPOSITE will appear ____ in the mouth.

Increases

As POLYMERIZATION occurs, the REFRACTIVE INDEX of the RESIN component _________ (more TRANSLUCENT).

1.1

(Continuous Curing) Uniform continuous curing.

1.2

(Continuous Curing) Step cure.

1.3

(Continuous Curing) Ramp cure.

1.4

(Continuous Curing) High energy pulse cure.

Uniform Continuous Curing

The light of CONSTANT MEDIUM INTENSITY is used for a period of time.

Uniform Continuous Curing

Utilized for QHT and LED light curing units. Most FAMILIAR and most COMMON curing techniques.

Step Cure

This curing technique INITIALLY USES LOW ENERGY then it is STEPPED UP into HIGH ENERGY.

Step Cure

(Technique) It is done to DECREASE POLYMERIZATION SHRINKAGE AND STRESS, allowing the composite to FLOW while in GEL STATE.

Step Cure - Ramp Cure

This technique is NOT USED for PAC and LASER curing units (2).

Ramp Cure

In this curing technique, LIGHT IS APPLIED IN LOW INTENSITY, then intensity GRADUALLY INCREASES over a period of time.

Ramp Cure

This technique DECREASES INITIAL STRESS and the DEGREE OF POLYMERIZATION SHRINKAGE.

High Energy Pulse Cure

This technique uses 3 OR 6 TIMES HIGHER ENERGY (1000-2800nW/cm2).

High Energy Pulse Cure

This technique is used for PAC, LASER, and 3RD LED generation curing units.

Discontinuous Curing Technique

A SINGLE PULSE OF LIGHT is applied to the composite material, followed by a PAUSE, then a SECOND PULSE, which is of HIGHER INTENSITY and LONGER DURATION.

Discontinuous Curing Technique

This technique is used for QTH curing units.

First Pulse

(Discontinuous Curing) Results in a SLOWING of the RATE OF POLYMERIZATION, DECREASING rate of SHRINKAGE and STRESSES in the composite material.

Second Pulse

(Discontinuous Curing) Allows the COMPOSITE MATERIAL to reach the FINAL STATE OF POLYMERIZATION.