Class III and V Composite Restorations Flashcards
What are the steps to a class III prep?
- Evaluate contact
◦ Caries usually occurs gingival to interproximal contact - Visualize outline form
◦ 2.0mm inciso-gingival height, 1.5mm mesial distal width - Begin preparation by entering tooth with bur PERPENDICULAR to long axis
◦ I prefer 330 bur (lab manual recommends #2 round- ok to start with to establish outline, decide which works best for you)
◦ May place wedge prior to preparing
◦ Keep path of entry in mind
◦ Common error- preparation that is perpendicular to the lingual surface - Extend preparation
◦ Depth= slightly visible from facial
What are the steps in composite resin restoration?
- Acid Etch (Rinse/dry)
- Prime (often included in bond step)
- Bond/Adhesive (Light cure)
- Place Composite (Light cure)
What does acid etching accomplish?
- Increases surface area
- Adhesive penetrates etched enamel (creating micromechanical bond)
What is the total etch system?
- Etch
◦ enamel for 20-30 seconds
◦ dentin for 15 seconds.
◦ Apply etchant to enamel first; 15 seconds later apply it to the dentin then wash off the enamel and dentin at the same time. - Rinse thoroughly 15 seconds.
- Dry enamel with an air syringe.
- May selective etch ENAMEL ONLY 20-30 seconds, rinse, dry
◦ When using appropriate bond agent (e.g. Adhese, but any Universal)
What is a selective etch enamel?
ENAMEL ONLY 20-30 seconds, rinse, dry
◦ When using appropriate bond agent
How long do acid etch enamel and dentin?
◦ enamel for 20-30 seconds
◦ dentin for 15 seconds
If the tooth you are etching gets contaminated with saliva what should you do?
re-etch for 10 seconds and then rinse again and dry until frosted enamel appearance is present.
Teeth rich in fluoride require _______ etching times
longer
- because fluoridated teeth are more resistant to acid
Fluoridated teeth are resistant to the ____________ produced by bacteria
lactic acid
What is the primer?
◦ Hydrophilic monomers in solvent
◦ Draws adhesive in
◦ This step is included with adhesive in our clinic
What is the bond?
◦ Resin bonding agent
◦ Also referred to as “adhesive”
The thin bonding agent engages the etched enamel through a…
micro-mechanical bond
The self-curing or light-cured resin then _________ bonds to the bonding agent
chemically
Primer/adhesive penetrate the intertubular dentin forming…
hybrid layer
How do you apply bonding agent?
- Apply adhesive with a brush
- Thin the solvent by blowing air gently
- Don’t overly air-thin adhesive
What kind of bond do we use in clinic?
Adhese Universal
◦ Vivapen- one-click dispense
What can happen if you apply too much bond agent?
the excess gets all over the occlusal surface, interproximal, even adjacent teeth
How do you prevent composite from sticking to instruments?
◦ Dip instrument into small amount of adhesive to work with the composite
◦ May use Wetting Resin in practice
What can happen if composite pulls back on the instrument?
voids in the restoration
Large class III restorations require ________ shades especially when the preparation can be seen through from the facial to the lingual.
opaque
Light will pass through _______ shades in large restorations thus making the restoration stand out in a patients mouth
translucent
What do you do if the surface of composite gets contatmined between increment layers?
RE-ETCHthe contaminated
composite surface
◦ re-apply bonding agent, thin, cure
◦ apply composite resin
After placement of composite restoration, an ____________ layer of resin will remain on the surface for a time
Oxygen-inhibited
Can additional composite be added directly to the oxygen-inhibited layer of composite?
YES!
- no need to re-etch and bond
What do you need to do to the surface of old composites when repairing them?
◦ roughen the old composite with a diamond bur
◦ then etch, wash, dry, bonding agent, thin, cure and apply new composite resin
What do you do when restoring two adjacent preparations?
PREPARE LARGEST FIRST
RESTORE SMALLEST FIRST
What are the cons of bulk placement of composite?
- increase in polymerization stress
- more post op sensitivity
- material can pul away from cavity wall leaving a void
The more walls the resin is _________ to helps to relieve the stress in the resin-adhesive interface
not bonded
What do you not use in class III restorations as a liner?
Do not use eugenol
- in IRM
- interferes with polymerizatio reaction
Where do you line in a class III restoration if necessary?
line dentin axial wall ONLY
◦ Use appropriate material (CaOH, Glass Ionomer)
◦ Avoid liner on enamel
◦ Take care to avoid liner in retention points, grooves
◦ More likely to need liner in younger patients
What patients are you more likely to need to use a liner in and why?
younger patients because of the large pulp
Why do you wedge a class III restoration?
- Wedge aids in separating the tooth for good contact and control seepage and moisture contamination
- Wedge is required to prevent gingival overhangs & to stop gingival bleeding or moisture seepage
What are the steps for placing a class III restoration?
- etch, rinse (clinic only)
- Apply bond agent
◦ Gently air dry and cure for 20 seconds - Adapt small layer of composite at gingival and labial wall
- Continue placing incrementally until preparation is slightly overfilled
- FOR FINAL INCREMENT: use clear matrix band to cure final layer to nice finish
- Remove excess
- If additional finishing is needed, use finishing carbide burs, finishing discs, finishing strips to finish
before moving on to polishing
Let the excess restorative material extrude toward the…
incisal
Is it easier to finish restorations incisally or gingivally?
incisally
Why do you use the mylar strip for the final cure/finish?
Tighten mylar strip around restoration and cure
◦ Results in smooth finish
◦ Eliminates oxygen interference
◦ Not necessary to polish this surface if it does not need contouring
Why is the metal plastic instrument called plastic?
it works with plastic material
* Composite resin is plastic
What is the overview of how to fill a class III restoration?
- Cover pulpal (axial) wall first, get in retention points/grooves (Cure between increments)
- Second layer (Cure between increments)
- Third layer
- Final cure with matrix tape
What should you mostly use to shape the class III composite restoration?
Should be shaped as much as possible prior to curing!
◦Plastic instrument, optrasculpt, mylar matrix band
What can you use to finish a class III restoration if needed?
- Use finishing burs
- Brasseler finishing discs
- Finishing strips
How do you check occlusion on class III restoration?
◦ Remove all occlusal prematurities in centric and excursions
◦ Occlusion should be on the tooth, not the restoration.
What do you do to prevent/deal with flash on the gingiva of a class III restoration?
- Avoid by better wedge and clear matrix band placement
- Remove with finishing strip (if small enough)
- Remove with bur (if large); Be careful not to gouge composite
What might be necessary to do before a class V restoration?
Use appropriate retraction and matrix
◦ Retraction cord may be necessary
◦ May use Cure-Thru matrix
What does the cure-thru matrix do in a class V restoration?
Compresses the material with a matrix into the Class V preparation while giving a great contour
What are the steps for a class V restoration?
- etch
- look for frosted enamel
- apply bonding agent and air dry solvent
- light cure
- apply composite and light cure
- remove excess with finishing bur
- polish
Where on the bevel/cavosurface do you bond/finish do on a class V restoration?
Bond to the end of the bevel and finish to the end of the bevel
Why should you avoid finishing on cementum in a class V restoration?
◦ This exposes dentin tubules
◦ Leads to sensitivity
What type of resin composite should you restore with?
Use nanofill or microfill
◦lower modulus of elasticity (less stiff) than hybrids
◦won’t flex as readily
◦less likely to debond
