Week 8- Class I, III, VI direct composite restorations Flashcards
according to the ADA, if done properly, posterior composites can have same longevity of amalgams?
true
longevity of posterior composite directly r/t factors such as
restoration size
caries risk
operator technique
what is the main contraindication of posterior composite?
area that cannot be isolated
large occlusal stresses
if box extends onto tooth’s root surface:
do not use composite
advantages of composite restorations
aesthetics conserve tooth structure less complex tooth preps insulation decreased microleakage short term strength of remaining tooth structure
disadvantages of composite restorations
polymerization shrinkage low fracture toughness technique sensitive greater localized wear unknown biocompatibility
contraindication to pit & fissure sealant
active caries on tooth
pit/fissure sealants use
low viscosity resin after etching
process of applying sealant
- clean tooth with pumice
- rinse
- etch
- apply sealant
true or false: you can combine a small class I restoration with sealant
true
primary choice of restoration for primary occlusal lesions
preventative resin and composite restorations
class VI restorations
small faulty developmental pit on cusp tip
lesion usually restricted to enamel
how is retention obtained in class I direct composite restoration?
bonding
class I direct composite restoration
create convenience form
retention obtained by bonding
small to moderate class I restorations
conservative flared cavosurface forms
no uniform or flat pulpal/axial walls
moderate to large class I restorations
flat walls perpendicular to occlusal forces strong marginal configurations enter tooth area most affected FIRST depth .2mm internal to DEJ follow central groove
to maximize polymerization effects
cure incrementally
restoration steps
- place adhesive/bonding agent over entire prep
- polymerize
- place liner if close to pulp, if not use glass-ionomer
RGMI
- bonds to dentin without opening tubules
- releases fluoride
- favorable elastic modulus = reduced shrinkage
how to offset negative advantages of high C factor?
use of liner
use of liner helps prevent
microleakage
contouring and polishing occlusal surface should use what bur?
carbide or diamond finishing
class II composite restoration should be used when:
periphery remains in enamel (no root involvement)
used to restore proximal contacts in class II restoration
wedges
small class II restoration methods
box technique
facial or lingual slot prep
box technique for class II
box technique if proximal surface defective but no lesions on occlusal surface
facial or lingual slot prep for class II
lesion accessed from facial or lingual side rather than marginal ridge
moderate to large class II restoration
prep 0.2mm internal to DEJ
keep faciolingual width as narrow as possible
dentin caries removed LAST after outline completion
when are dentin caries removed in class II?
LAST, after outline completion
axial wall of class II prep should be:
0.2mm internal to DEJ
have outward convexity
true/false? you should bevel the lingual walls of class II prep?
false; do not bevel prep but remove unsupported enamel rods
restorative technique for class II: most important things
selection and proper placement of matrix
matrix for class II
ultra thin metal matrix placed PRIOR to adhesive placement
bovine ring
stabilizes matrix band
provides additional tooth separation
you should restore what part of class II restoration first?
box
true/false: if composite is stiff, it can be heated prior to insertion
true
what tool is used to remove interproximal overhang?
no.12 surgical blade
full coverage, extensive class II prep
add additional retentive features such as grooves, locks, slots
why are extensive class II preps not recommended?
decreased tooth structure available for bonding
increased concern for retaining composite in tooth
extensive class II prep differences
cusps may be capped
greater extensions in most areas
secondary retention features
more resistance forms
where to make depth cuts in extensive class II prep?
into a cusp that will be capped early in prep
reduced cusp relatively flat
problem with reduced cusp
significantly reduces retention and resistance form
cusp capping does what?
restorative material to increase tooth resistance form
in an extensive class II restoration, where will most of composite bond be?
to dentin
therefore, more technique sensitive
