Physics and Chemistry of Light Curing - incomplete curing Flashcards
What is the consequence of incomplete curing?
pulpal inflammation (uncured acidic components may cause trauma)
discolouration and marginal staining
decreased wear resistance, compressive and flexure strengths
What do you call formation of marginal gaps?
microgaps
What can a marginal gaps lea to?
microleakage and other potential sequence such as secondary caries
What can effect the light curing process?
manufacturer
clinician
What are factors the manufacturer can control about light curing?
opacity / translucency of material
variables in diketone / amine chemistry
particle size
What are factors the clinician can control about light curing?
follow the DFU
ensure the light will penetrate through darker material
exit portal of light guide should be parallel to the surface being cured - even curing
What is the importance of depth of cure?
maximum depth at which adequate polymerisation of a material is achieved on exposure to light energy
soggy bottom
what do you follow when using light curing?
DFU
directions of use
What are the range on light curing programmes?
slow cure/low power
ramp cure
soft start
boost/ high power
What is the slow cure/ low power light curing programme?
light energy remains at intermediate level an curing time is increased
What is the ramp cure light curing programme?
energy increases linearly with respect to time over period of cure
probably the best
What is the soft start light curing programme?
light energy starts at low level and then reverts to maximum output
What is the boost/high power light curing programme?
constant emission of light energy at maximum output
How do you calculate the energy needed (rate of cure)?
is the product of the intensity of the light with the time of application
How do you calculate the dose (energy required)?
maximum curing time x intensity
How long should a composite be cured for with a curing lamp whose output is 1000mWcm2?
