Midterm 1: O Composite Prep + Restoration + Adhesives and Composites Flashcards
What are the cavity classifications?
Class I
Class II
Class III
Class IV
Class V
Class VI
What is a Class I Cavity?
pits and fissures of occlusal surfaces of posterior teeth
occlusal 2/3 of buccal and lingual of molars
lingual of maxillary incisors
What is a Class III Cavity?
Proximal surfaces of anterior teeth
What is a Class II Cavity?
proximal surfaces of posterior teeth
What is a Class V Cavity?
Gingival third of teeth
What is a Class IV Cavity?
Proximal surfaces and incisal edge of anterior teeth
What is a Class VI Cavity?
Incisal edge of anterior teeth and cusp tips of posterior teeth
The ICDAS uses __________ assessment, NOT sharp instruments.
visual
What ICDAS categories are in the moderate caries management stage?
ICDAS 3-5
Which ICDAS categories are in the severe caries management stage?
ICDAS 6
What ICDAS categories are in the initial caries management stage?
ICDAS 0-2
What is the cavosurface margin?
The junction of a prepared wall and external surface of the tooth
where the CAVITY preparation meets the ORIGINAL tooth surface
What is a line angle?
line between two points
junction of two walls
What is a point angle?
junction of three lines/walls
What is the outline form?
external outline of the tooth surface to be included in the prep along the cavosurface margin
What is retension form?
prevention of restoration displacement
What is convenience form?
access and visibility
What is resistance form?
prevention of restoration (and/or tooth) fracture from occlusal forces
What is the mesio-distal angulation of mandibular teeth?
Bur is tipped lingually
Why are buccal/lingual walls parallel to slightly truncated on the long axis of the crown?
help in retention
avoid damaging the pulp
What is the 6th gen self etch technique?
self etching primer and adhesive separate
What is the 7th gen adhesive system?
etch, primer, adhesive combined into one
What is the selective etch technique?
35-37% phosphoric acid etch
etchant only on enamel
rinse off after 15 seconds
dry
Why do we scrub the scotchbond onto the preparation for 20 seconds?
To ensure the adhesive gets into the grooves created by the etch
What are the components of the ultradent wetting resin?
45% filled resin
no solvents
does not inhibit polymerization
use very small amount
prevents composite from sticking to instrument
What are neoshine polishers?
designed to polish nanocomposite
What does Satin Neoshine Polishers do?
removes scratches and imperfections for a smooth shine
What are Hi-Gloss Neoshine Polishers?
high luster
TRUE OR FALSE
enamel bonding is reliable, predictable, and strong
TRUE
Acid etching transforms smooth enamel surface into what?
irregular (porous) surface
What is the smear layer?
layer of organic and inorganic debris that seals the dentinal tubules
reduces permeability
caused by instrumentation of the preparation
Why is the smear layer bad or good?
BAD: interferes with adhesion
GOOD: reduces post operative sensitivity
How does the smear layer reduce post operative sensitivity?
smear layer PLUGS the dentin tubules
prevents the fluid inside to be exposed
Which is easier: dentin bonding or enamel bonding? Why?
Enamel bonding
enamel structure is more structured/predictable
therefore easier to etch
DENTIN TUBULES and collagen are like a MAZE
Dentin is filled with fluids and enzymes that may interfere with bond integrity
Dentin bonding includes which three steps?
Etch
Primer
Adhesive (Bond)
What is the purpose of etch?
removes the smear layer
Etched enamel creates what?
microporosities
chalky/froster white appearance if you air dry it
What does etched dentin do?
exposes layer of collagen
widens dentinal tubules
Is resin hydrophobic or hydrophillic?
hydrophobic
Primer contains a ________________- end that interacts with the moisture on the tooth and a _____________ end that provides bonding sites for the adhesive
Hydrophilic
Hydrophobic
What is the primer’s function in dentin bonding?
infiltrates dentinal tubules
wets dentin surface
prevents collagen collapse
keeps the “spaghetti” moist/upright for micromechanical interlock
Do we need primer for enamel bonding?
No
What is Bis-GMA
part of adhesive/bond
bonds to underlying primer and overlying composite resin
Why do we gently air thin the primer and the adhesive for a few seconds?
to evaporate the solvent which we no longer need at this point, leaving a nice thin layer of primer/adhesive inside the cavity prep
TO MAKE THE LAYER THIN AND NOT TOO BULKY
What does the primer and adhesive create?
the hybrid layer
What type of interface does the hybrid use?
mechanical
What are resin tags?
adhesive resin lock into the microporosities of etched enamel and dentinal exposed collagen and widened tubules
What kind of bond is there between the tooth structure and the prime/bond (adhesive)?
Micromechanical
What kind of bond is there between the primer, the adhesive, and the resin?
Chemical
Which generations reduced post op sensitivity since smear layer is providing some sealing of dentinal tubules?
6/7
What are the components of composite resin?
- Resin Matrix
- Filler (Silica)
- Coupling agent (Silane)
What are the characteristics of resin matrix?
Bis-GMA (resin) + initiator
monomers become polymers after curing light
negligible health hazard
What are the characteristics of filler (silica)?
Radiopaque
various shapes/sizes
affect properties of the composite
What are composite types (according to filler size)?
- Macrofill
- Microfill
- Hybrid
- Nanofill
- Nanohybrid
What are the characteristics of coupling agent?
Promotes adhesion (chemical) between the filler and resin matrix
What are the characteristics of macrofill?
large particles
good fracture resistance
low shrinkage
poor wear resistance
poor polish
What are some characteristics of microfill?
very small particles
fractures easily
more shrinkage
better wear resistance
polishable
What are the characteristics of nanofill?
clusters of extremely small filler particles
glomerate to provide full range of filler sites
What are the characteristics of hybrid?
combines the good properties of micro/macrofill
What are some characteristics of nanohybrid?
incorporates the nanofill particles and integrates them with other sizes
What are the composite types (according to the way it polymerizes)?
- Self-cure
- Light-cure
- Dual cure
What are the composite types (clinical)?
- flowable
- packable
- fissure sealant
What is polymerization shrinkage?
composite resin restorations shrink after curing