9. Bases and Liners Flashcards
Effect of Restorative Procedures on the Pulp • \_\_\_\_ of cavity preparation • Frictional heat • \_\_\_\_ of dentin • Cavitycleansing • \_\_\_\_ etching of dentin • Restorative materials • \_\_\_\_
depth
desiccation
acid
polishing
Pulpal Response
• Tissue is confined within a ____, unyielding environment (pulp chamber)
• No ____ circulation
– to facilitate removal of irritants and enhance
repair
Therefore, the ____ is more vulnerable to injury than other similar tissues…
rigid
collateral
dental pulp
Pulpal Response
The remaining ____ from the pulpal extent of cavity preparation to the pulp is the single most important factor in protecting the pulp from insult
dentin thickness
Pulpal Protection
Many restorative materials that provide excellent properties for the bulk of a dental restoration, may not ____ the dental pulp during ____ or during cyclic thermal or
____ stressing
protect
setting
mechanical
Pulpal protection
- ____ protection - Leakage of restoration
- ____protection - Dissimilar metals in the mouth like amalgam against gold restorations can cause electrical problems
feeling sensitivity
- ____ protection - don’t want pt to feel pain when eating ice cream or from hot drink > want to protect tooth from thermal changes
- ____ medication - medication can help pulp heal in deeper restorations
- ____ Protection
chemical electrical thermal pulpal mechanical
Liners and bases are materials placed between \_\_\_\_ (and sometimes \_\_\_\_) and the restoration to provide pulpal protection
dentin
pulp
Pulpal protection
Have an amalgam in the tooth
• if we don’t optibond it, then we are waiting for the amalgam to corrode which seals it
• Another option: bond amalgam to place so ____ can seal. When amalgam breaks down, gap starts to open up and will get recurrent decay
• Good thing about amalgam is that it continues to corrode so it can last for many years and
seal themselves
In deeper restorations where the decay (in red) is close to pulp horn, we can put ____ in and put a ____ where dentin was lost.
• Base (orange) provides ____ protection -> doesnt have to be
condensed hard
• When you condense the amalgam, you are condensing on the ____ and not on the thin dentin
• Also provides ____ protection
interface medicament base mechanical base thermal
Pulpal Protection
There is convincing evidence that ____ growth beneath restorations is the ____ cause of pulpal injury
bacterial
primary
Pulpal Protection
• Bacteria will penetrate the ____ and ____, which may cause recurrent caries, pulpal irritation, or ____ necrosis.
marginal gap
dentinal tubules
pulpal
Pulpal hydrodynamics
why is the tooth sensitive?
• if there is ____ movement in the dentin tubules, this can cause pain for pt
• It is a stimuli that induces fluid movement in the tubules where the tubules distort the ____
process in the affront nerves
• As the fluid moves, it pulls on nerve and activates it -> causing pain
• This is why you can do an occlusal adjustment in pt ____ and they are fine
◦Once you go through the enamel and into the dentin, they jump
◦Why? When you go into the dentin, the high speed handpiece is moving fluid into the ____ ->
feel PAIN
◦You can sometimes can in with ____ speed w/o fluid and pt is ok b/c NOT MOVING ____
fluid odontoblastic enamel dentin low fluid
Pulpal Hydrodynamics
• If restoration is not well sealed, fluid flows out ____ and into space between restorative material and tooth surface.
– Stimulus (ex. Hot/cold) causes change in ____ rate, which is interpreted as painful by ____
dentinal tubules
flow
mechanoreceptors
Objectives of Pulpal Protection
If leakage of chemical irritants from ____ materials or ____occurs
____ complex can become inflamed
To protect against these events, need to seal the outer ends of the tubules along the ____ cavity preparation wall
dental
bacteria
pulp
dentinal
Tooth sensitivity
Some pts have no caries or periodontal disease, but they have ____ -> will get sensitive teeth
• there are products you can seal the dentin tubules
• ____ use coats the tooth and seals it
• Fluoride (____) can help with sensitivity
sensitivity
oxalate crystals
prevident 1.2%
Pulpal hydrodynamics
If tubules can be occluded, ____ flow is prevented and ____ cannot induce pain.
Therefore, sealing of the dentinal tubules will decrease temperature senstiivty (generally to ____)
fluid
cold
cold
Smear Layer
Cutting debris from rotary instruments, which is ____ on the cut surface
Enamel and dentin smear layers are left in ____ for unbonded amalgam restorations
Dentin smear layer produces some degree of ____ sealing
compacted
place
tubule
Smear Layer
• Very effective barrier
– Limits ____ of potentially toxic substances to pulp
- Cannot be invaded by ____
• But permeable to bacterial ____
• Because it is partially porous, it can not prevent ____ diffusion
- This produces ____ protection
diffusion
bacteria
products
slow long-term
chemical
Smear Layer
All of the decay has been removed here and a smear layer is produced
• there are ____ that seal it
• When bonding, we put ____ here taking the smear layer away, replacing with ____ to bond it
smear plugs
acid
resin
Terminology
Cavity Sealers:
Provide a protective coating for freshly cut tooth structure of the prepared
cavity. Consist of ____ , ____ and ____ agents.
varnishes
desensitizers
dentin bonding
Desensitizers
• Gluma
35%____ (hydroxyethyl methacrylate)
5% ____
HEMA is a ____
• it seals the tubules Glutaraldehyde is ____
The combination works very well when pt comes in with no ____ and you don’t think they need an endodontic procedure.
• put Gluma on and pt feels great and wont feel ____
when they rinse with water -> no pain anymore
HEMA glutaradehyde resin antibacterial caries pain
Dentin Bonding Agents
• Used as cavity sealers
• Demonstrated ____ bonding ability to bond restorative material to tooth
• Used to bond ____ and ____ to tooth
multisubstrate
composite resin
amalgam
Terminology
Liner:
____ layer of material used primarily to provide a barrier to protect the ____ from residual
reactants diffusing out of a ____ and/or oral fluids which may penetrate ____ tooth- restoration interfaces
Liner is added before you ____ the tooth
thin dentin restoration leaky restore
Reasons for Use
• Liner
– Seal ____
• Provides ____ barrier to bacteria and their products
– Prevent removal of the ____ by acid
etchants, reducing the potential for increased
dentin ____
If you do composite and put acid on the tooth, it will remove the smear layer and opens up all of the tubules
• we may not want to do this in a ____ restoration
• We can put a liner first and then acid etch so those tubules wont open up
dentin physical smear layer permeability deep
• Liner
– Therapeutic effect
• Protect against ____ irritation by restorative materials
• Contribute initial ____ insulation
Ex: you put a deep amalgam next to dentin which is close to the pulp next to a gold crown, and when the amalgam corrodes, 2 dissimilar metals can cause electrical problem
• may not feel pain, but will feel ____
• If you put a ____ under the restoration, it is less likely to be perceived
• Once ____ is over, wont feel anything
- Generate some ____ protection
- May provide pulpal treatment - Used for ____ and ____ pulp cap
chemical electrical weird liner corrosion thermal direct indirect
Reasons for Use
• Liner
– Greatest need with ____ restorations not
well-bonded to tooth
Need this for ____ and ____ crowns (where the tooth is ____ and hasn’t gone under endodontic treatment)
metallic
amalgams
gold
vital
Clinical Considerations
Applied with minimal thickness (
0.5 dentin pulpal axial lateral
Materials Liners – \_\_\_\_ – \_\_\_\_ – \_\_\_\_
Calcium Hydroxide
Zinc Oxide Eugenol
Glass Ionomer
Calcium Hydroxide
• Traditionally the most ____
• Thought to stimulate formation of ____ dentin
– NO CONCLUSIVE EVIDENCE, UNLESS ____ PULPAL CONTACT Cox CF et al., 1992
• Frequently ____beneath restorations (major ____)** (high ____)
• Usually ____ component (paste/paste)
popular irregular secondary direct dissolve disadvantage solubility 2
