operative questions Flashcards
Forming the hybrid layer consists of?
a. Acid etch
b. Rinsing tooth
c. Adhesive
d. Curing
e. All the above
all
What is the sequence of reactions for polymerization reaction?
activation
initation
propagation
termination
Beveling the gingival floor of a Class II helps with what?
expose enamel rods
f a patient has a heavy centric occlusion on number eight for a class IV, what should
you do?
do not place lingual bevel
You should remove all of the following in a class III preparation, except?
a. Gingival contact
b. Facial contact
c. Incisal contact
d. Lingual contact
c. Incisal contact (becomes Class 4)
Increasing the filler size amount will do what?
increase strength
(and decrease polymerization shrinkage)
When removing carries, all affected dentin should be removed completely (TRUE or FALSE).
false
remove all infected
the smear layer consists of what?
debris from bur, bacteria, cells
Incremental placing of composite in a Class II box will do what?
decreases stress
acid etching does what to prep
increases SA
and surface energy
(place for resin can penetrate to form resin tags)
Which would you not use to finish?
a. Pineaapple bur
b. Polishing cup
c. Diamond bur
pineapple
Which dilutes the resin matrix
TGDMA
What is the initiator for chemical cure
benzoyl peroxide
initiator for light cure
camphorquinone
Procedure of doing a composite in order
etch
bond
finish polish
You should re-etch when what happens?
prep becomes contaminated with saliva or blood
Self-etch is more predictable than total-etch (TRUE/FALSE)
false
How should you prep and restore two adjacent teeth in order if they’re next to each other.
prep large lesion first
restore small lesion first
T/F enamel wears 25-125 times easier than dentin.
FALSE, dentin wears faster
2 questions on most likely place where carious lesion are on a class III
lingual and gingival to contact
Composite sticking to instrument can do what.
create voids
Flowable for 1st increment of box.
increasing bond/seal
(decreases microleakage)
Where does Enamel bind stronger to?
enamel rods
NOT SIDES
coupling agent
couples filler with resin
silane
what do you remove
smear layer
etching will
increase surface area and surface energy
elastic modulus also means
stiffness
what do you use for class III
a. mylar strip
b. tofflemire
c. clear strip
mylar strip
palodent best used for
small class 2 compo
when more filler is added
increases hardness
(and increases strength and decreases shrinkage)
why do you use increments
minimize stress
where are dentin tubules widest
at pulp
why is bonding to dentin harder
dentin more heterogeneous
which agent serves to lower viscosity of comp resin
TEGDMA
best agent to fill abfraction/ class V lesions
nano and micro
what causes irritated tissues
tofflemire
palodent should be palced
1mm above margin of adjacent tooth
what does cure thru matrix do
achieve best contour (used for class v)
how much should you break thru facial contact in class III
.25mm
minimally broken
all the following are true about s curves but
make walls diverge
what does methacrylate monomers in bulk fill do
relieve stress
(reduces shrinkage stress)
axiopulpal line angle is BEVELED in amalgam to improve
resistance
what do you reccomend to pt with sens
toothpaste with KNO3 aka potassium nitrate-> blocks fluid movement
is it ok to leave unsupported enamel in class III prep
true
what class has highest c factor
class I
reason for doing flowable in bottom of box
improve gingival margin seal
what should you do if you have heavy contact on L of class III
do not bevel
result from comp sticking to tool
voids
softest to hardest
cementum
dentin
enamel
what do you do before putting on rubber dam
select tooth shade
what teeth isolate
one posterior two anterior
two adjacent preps:
prep largest first
restore smallest first
layering technique = incremental placement and creates
less stress
oxygen inhibited layer
kept sticky and wettability to add more comp
gingival inflammation
from improper wedging
what causes gingival irritation
OVERCONTOURED = most damaging to periodontitis
dentin adhesive bonding best described by
collagen and resin interlocked intertubular dentin
pt had DO done on 4. now has cold sensitivity and inflamed gums
1. causing gingivitis
2. cause of cc
3. what should you have done first
- premature occlusion ( i wanna also say it could be overcontoured on Distal thats causing gingivitis but idk)
- fluid in dentinal tubules
- condense box (or maybe prep with better matrix system???)
lower polymerization stress shrinkage means lower c factor.
c factor is bonded divided by unbonded surfaces
both true
adhesive solvent used at umkc
ethanol
bonding agent ____bonds to enamel
micromechanical
bonding agent ____bonds to dentin
micromechanical
bonding agent _____bonds to resin
chemicaly
collagen+ resin form; intertubular dentin bond here
hybrid layer
Collagen and resin layer
Want to form with dentin
Interlocking of resin with demineralized collagen
hybrid layer
tooth flexing and bending
abraction
abfraction affects what portion of tooth
cervical
prismless enamel found where
cervical
bevel for class II
axiopulpal line angle
what leads to most post op sens
bulk fill
what do methacrylate monomers in bulk fill do
relieve stress
why do you flare on cavosurface
to expose ends of enamel rods
why do you NOT bevel
exposure sides of enamel rods
longevity of tooth
fracture toughness
stress on tooth that causes flexure and stress on cervical area of tooth
abfraction
if you dont prepare with long axis of tooth, then what
undefined internal line angles,
inadequate retention for composite,
pulp damage (but was not option)
bond to smear layer?
NO
flare on cavosurface to expose
ends of enamel rods
advantages of rubber dam
better visualization and access
-clean
-material works better
-prevents injury
-prevents injury
goal of adhesive with composite
in enamel:
in dentin:
enamel: interlocking with enamel rods
dentin: interlocking with dentin collagen
etch and rinse (total etch) explained
- 3 steps, 2 bottles
- etch
- prime
- bond
or
1. etch
2. prime+ bond
(UMKC method)
*stronger bond
*enamel ADEQUATELY PREPARED
self-etch explained
- 2 steps, 1 bottle
- acid primer + bonding agent
-acid primer partially dissolves smear layer, allows penetration of bond resin
(basically just one thing)
*will not etch unprepared enamel
*lower bond strength
perpendicular oriented enamel
- cavosurface margins of class I prep
- bevels of class II prep
- ends of enamel rods
parallel oriented enamel
- internal walls of occlusal preps
- gingival floor of box of class II preps
- sides of enamel rods
ideal occlusion
posterior teeth axial loading
=load long axis of tooth
max and mand functional and nonfunctional cusps
max
functional: lingual
non: buccal
mand
functional: buccal
non: lingual
methods to ensure you restore patient’s occlusion properly
- check occlusion with marking paper BEFORE anesthetizing
recreate it - visually evaluate contralateral side to where working on
- check occlusion again when pt sitting up
if restore wrong what happens to occlusion
- pain biting
- fractured cusp
- fractured restoration
- premature contact
- trauma on pdl
- trauma to TMJ
different components of dental composite resin
- resin matrix
- filler particles
- silane coupling agent
for regular composite, what are the difunctional monomers and which dilutes
- bis-GMA
- UDMA
- TEGDMA- this dilutes (less viscous)
coupling agent (silane) creates better stress distribution betwen
resin and filler
flowable bulk fill is in ___only
fullbody bulk fill in is
flowable- dentin only
fullbody- dentin and enamel
4 types of sealants
- resin based
- glass ionomer
- polyacid-modified resin
- resin-modified glass ionomer
describe resin based sealant
most common
not moisture friendly
describe glass ionomer sealant
moisture friend
poor retention but more working time
fluoride releasing
describe polyacid-modified resin
resin base with fluoride releasing and adhesive properties of glass ionomer
continuously releasing fluoride
moisture sens
describe resin-modified glass ionomer
glass ionomer with resin components
longer working time
with sealants you need a dry environment (especially for resin based) and clean area
do what and not do what to clean
do: use pumice and prophy brush, air, enameloplasty
DONT: use prophy paste
preventive resin restoration PRR is done on:
sealants are done on:
PRR- initial caries present (cant be in dentin)
sealants - noncavitated teeth
active ingredient in sensitivity toothpastes
potassium nitrate (KNO-gunpowder)
3 different non-carious causes of class V lesions
- erosion- acid, gerd, bulimia
- abrasion- wear, toothbrush, bruxism
- abfraction- flexure of tooth, mechanical loss of tooth structure
class III dimensions for central and lateral tooth
M-D and G-I
central
M-D 1.5mm
G-I 2.0mm
lateral
M-D 1.0mm
G-I 1.5mm
retention for class III
incisal point
gingival groove (
contacts of class III
incisal= intact
gingival=broken
facial= 0.25mm minimally broken
class V prep
walls diverge
axial wall convex
bevel (increases SA retention and reduces microleakages)
add retention grooves
causes of tooth sensitivity
- caries or leaky restoration
- voids-> fluid flows into voids
- premature contact
- exposed dentin->recession
- post-perio surgery
- abrasion and erosion
use Myler strip finish when
in class III (matric and wedge)
use this for added retention when cant bevel in class III
dovetail lock
