Class 1 composite restoration- caries removal Flashcards
when composites were first a thing, how were they cured?
chemically and were used for class 3,4,5
whats has changed with modern composites vs older composites?
Filler size has reduced, and filler amounts have increased up to 70%
whats a nano-hybrid composite?
the smaller filler particles ( nano particles) are intermixed with larger glass and silica particles giving the material toughness.
what composite system do we use at LECOM?
BEAUTIFIL Nanohybrid
do The prep walls have to be convergent?
no they can be parallel to divergent
the prep pulpal depth should be __ past the DEJ?
.5 mm
Advantages of Composite?
Esthetics, conserve more tooth structure, easier preparation, insulation
Disadvantages of composite
Shrinkage, Lower fracture toughness, possible greater localized occlusal wear
on average the composite shrinks how much?
2.6-7.1 %
Do you want centric stops to be on composite or amalgam?
no, They need to be on natural teeth.
how wide should the isthmus be?
1.5mm, also dont encroach past 1/3 of the cusp tip of the cusp
Retention is achieved by micromechanical means which means…..
- etching of enamel and Dentin
- proper bonding technique
- placing bevels
Does the beutibond bond to the tooth?
no , the adhesive
What bur is best to use for entry?
330 or 245
how far pulpal should you go down?
~1.5 mm initially, then you can go 2mm. as you continue to drill
what bur can you use to smoothen the walls?
use a low speed 56 carbide bur
what should the marginal thickness be?
Premolars is 1.5mm, molars, 2 mm.
why dont we bevel the occlusal surface?
it creates a very thin and weak composite area that is prone to chipping and increases recurrent caries risk.
where can you bevel?
facial or ligual of a tooth ( since its not under stress its ok)
why do caries spread at the DEJ?
a lot of tubules
what MUST be achieved before caries removal pulpally begins?
a stain free DEJ
how do we distuingish between healthy and infected dentin?
degree of discoloration and hardness.
who developed the caries indicator? Why is it not good?
Fusyama, its not specific for infected dentin and stains slightly demineralized protein matrix of affected dentin as well.
Caries removal process
use spoon excavator, start with the largest spoon and move to smaller sizes if needed, Remember the stain free DEJ
Rotary caries removal
start with larges removal bur with the slow speed, start to remove caries from the periphery towards the center, use 10,000 rpm with no water,Begin with a #6 caries removal bur and proceed to smaller burs until all caries is removed and there is no soft dentin.
STAINED but firm dentin is AFFECTED and can remain
Indirect pulp cap criteria/ process
must be asymptomatic, a small amount of caries is left in the deepest portion of the prep, This area is covered with calcium hydroxie ( dycal), trioxide aggregate + a base, High pH of CaOH kills remaining bacteria, CaOH/MTA encourages formation of reparative dentin,
what does Iatrogenic mean?
injury caused by injury
what happens if there is an accidental pulp exposure?
cover it with dycal IF it is a non-carious exposure. If it is carious you need to do a root canal.( the bacteria has already entered )
how can you prevent iatrogenic exposures?
check the bite wings thoroughly to make sure you know where the pulp horns are before operating.
who has high pulp horns?
younger people.
What can you do if there is a carious pulpal exposure?
you can do either endodontics or extraction.
