Class III, IV, and V Composite Preparations Flashcards
Select shade before
placing rubber dam
◦ Dehydrating tooth affects shade
Avoid — on tooth
shining overhead light/loupes light directly
Unsure?
Cure small blob of composite on tooth to check shade
◦ Do not etch nor bond- composite will flick off easily
Class III Preparation: Shade
selection Be mindful
(2)
◦ At least three color esthetic zones on a tooth
◦ TAKE SHADE FROM PORTION OF SHADE GUIDE MOST SIMILAR TO THICKNESS OF RESTORATION
MARK — PRIOR TO APPLYING DAM
◦ Avoid margins ending in occlusal contact areas
OCCLUSION
Class III Preparation
Approach from the — when possible
lingual
Class III Preparation
Approach from the — when possible
lingual
Class III Preparation
Approach from the lingual when possible
◦ Acceptable to leave unsupported enamel on facial wall of preparation
(5)
◦ Esthetics improved
◦ Discoloration and deterioration is less visible
◦ Color match is easier
◦ Facial enamel is conserved
◦ WEDGE SHAPED PREPARATION
Class III Preparation Minimal extension
Protect adjacent tooth
Where is caries?
(2)
◦ Usually more lingual than facial
◦ Gingival to contact area
Preserve — contact
◦ It may be acceptable to leave sound undermined enamel here
incisal
Remove — from margins
◦ You can’t see these- must visualize based on rod location
loose enamel rods
Begin outline form
◦ Prepare — to long axis
PERPENDICULAR
Inciso-gingival length
◦ — on maxillary lateral
◦ — on maxillary central
1.5
2.0
Mesial distal width
◦ — on maxillary lateral
◦ — on maxillary central
1.0
1.5
— contact is broken
— contact is intact
Gingival
Incisal
Inciso-gingival height=
2.0mm
Mesio-distal width=
1.5
— not always required
Place in dentin!
◦ Do not undermine enamel
Incisal Point
◦ Place with
Gingival groove
◦ Place with
Retention
½ or ¼ round bur
½ or ¼ round bur
Class III Preparation Retention
(2)
◦ Deeper than normal prep= avoid placing retention to avoid pulp exposure
◦ Place point and groove where they would be in an ideal prep
Class III Preparation
BEVEL
(4)
◦ Place 1mm bevel lingual and facial
◦ 45-60 degrees
◦ Smooth, even
◦ Flame-shaped diamond bur
Class III Preparation
Break — contact
◦ MINIMALLY
facial
Class III Preparation
Variations
◦ Root surface caries
◦ Same prep but
◦ DO NOT BEVEL on dentin or cementum
Class III Preparation
Variations
DO NOT BEVEL
◦ If there would be
heavy centric contact on margin
◦ Enamel wears better than composite
◦ Enamel is stronger than composite
Class III Preparations
Variations
◦ Facial approach
(4)
◦ When lingual access may involve only centric contact of tooth
◦ Irregular tooth alignment or rotation
◦ Extensive caries on the facial
◦ Existing defective restoration on the facial
Class III Restoration
— usually not necessary
Pulp Protection (Liner)
Do not use —
why?
eugenol
◦ Found in IRM
◦ interferes with polymerization reaction.
Do not use eugenol
◦ Found in IRM
◦ interferes with polymerization reaction.
If needed, line — wall ONLY
(6)
dentin axial
◦ 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
◦ Larger pulp
Matrix and Wedge Application
(5)
Wedge the matrix at the gingival to hold it against
the tooth.
Wedge aids in separating the tooth for good
contact and control seepage and moisture
contamination.
Minimizes finishing time.
Wedge is required to prevent gingival overhangs &
to stop gingival bleeding or moisture seepage.
SPEND TIME ON THIS STEP!!!
Removing Excess Material
Let the excess restorative material extrude toward the incisal
◦ easier to finish incisally vs. gingivally
The Mylar Strip Finish Tighten mylar strip around restoration and cure
(3)
◦ Results in smooth finish
◦ Eliminates oxygen interference
◦ Not necessary to polish this surface if it does not need contouring
Metal Plastic InstrumentThe instrument is metal
BUT it works with
plastic material
* Composite resin is plastic
Steps of placement
(6)
Cover pulpal (axial) wall first, get in retention points/grooves
Cure between increments
Second layer
Cure between increments
Third layer
Final cure (Larger preps require additional layers and vice versa)
Shaping and Finishing Should be shaped as much as possible prior to curing
◦ Plastic instrument, matrix band
Use
(3)
finishing burs
Brasseler finishing discs - (coarse, then medium, then fine, then superfine)
Finishing strips (strip from the gingival to the contact if necessary, do not strip and remove the
contact).
Shaping and Finishing
— preferable when finishing lingual surface
12 bladed finishing burs (round or bullet shape)
— blades smoother than — blades
(like sandpaper- higher grit= smoother)
12
6
Lingual excess of material
Check occlusion
(2)
Remove composite back to the —
◦ Remember your preparation
◦ Remove all occlusal prematurities in centric and excursions
◦ Occlusion should be on the tooth, not the restoration.
cavosurface bevel
Flash on gingival
(4)
check that there is no overhangs in this area with the
explorer. If there is use a sharp gold knife to remove.
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
Finishing Strips
(4)
Thread below contact
Use above contact
Non-abrasive area in center- can “floss” through contact without removing material
AVOID STRIPPING AWAY CONTACT
Class IV Preparation – classic “chipped
tooth”
Same principles as Class III BUT
the incisal angle is missing
◦ Increase in restorability difficulty level!
Increase the bevel and extend beyond the bevel with the resin for
more retention and a better esthetic appearance.
Resin Extension for large fracture
A labial veneer or full coverage crown may be necessary on a
large fracture for extra retention.
Class V Preparation
-Carious lesion in gingival third of tooth
◦ Can be buccal or lingual
Curing Light
Light must have sufficient output
◦ > 550mW/cm2
Class V Preparations
Axial Wall is —
Mesial and Distal Walls —
Incisal gingival height= —
Axial depth —
convex
diverged
1.5mm
1.0mm
Class V Preparation
Beveled
(4)
◦ USE DIAMONDS
◦ Increases surface area
◦ Increases retention
◦ Reduces microleakage
◦ Reduces microleakage
(2)
◦ Reduces margin discoloration
◦ Eliminates white “halo” effect= better esthetics
Bevel ENDS of
enamel rods
Add
Retention grooves
Class V Preparation When do we NOT bevel?
◦ Below CEJ
◦ We’re in cementum then- no need to expose enamel rods for better bonding
Class V Preparation
Modification for shallow caries or decalcified enamel adjacent to
Class V caries
◦ Basically an extended bevel
Class V restorations may extend onto the
root surface
◦ Polymerization shrinkage is greater than bond to cementum/dentin
◦ Causes contraction gap
Retention groove
◦ can minimize —
gap
Consider other restorative materials
(2)
◦ RMGI
- May reduce microleakage
◦ Amalgam
Class V Considerations
Non Carious Cervical Lesions
(3)
◦ Abrasion- wear
◦ Erosion- caused by acid
◦ Abfraction- mechanical loss of tooth structure
◦ Abrasion- wear
◦ Toothbrush, pen chewing, occlusal wear from grinding
◦ Erosion- caused by acid
◦ Bulimia, GERD, alcoholics, extreme diet
◦ Abfraction- mechanical loss of tooth structure
(2)
◦ Loading forces aren’t where they’re supposed to be
◦ = flexure of tooth and failure of enamel and dentin
Dentin wears — times easier than enamel
25-125
Abrasion
◦ Discuss
habits with patient, including brushing
Bond strength to natural sclerotic dentin is —% lower than to sound cervical dentin
- REMOVE with bur
25-40
Erosion
Discuss (2)
◦ Discuss diet
◦ Chew/suck on lemons
◦ Frequent soda/energy drink intake
◦ Discuss medical history
◦ Acid reflux
◦ Bulimia
◦ Dry mouth from medications
◦ Lack saliva to buffer acid
Class V Considerations
Abfraction
(5)
◦ Flexure and fatigue of enamel and dentin
◦ Caused by occlusal forces
◦ Microfractures
◦ Heavy occlusal force in lateral or eccentric occlusion
◦ Stress is concentrated at cervical area of tooth, causing fractures
Class V Considerations
When to treat Non-carious Cervical Lesions?
(5)
◦ Lesion is deep enough to compromise tooth
◦ Sensitivity
◦ Involved in partial denture design
◦ Defect is approaching pulp
◦ Defect contributes to a periodontal problem
◦ Sensitivity
(2)
◦ Attempt non-surgical treatment of sensitivity first
◦ Toothpaste, topical fluoride, etc
Defect contributes to a periodontal problem
Overcontoured restorations more likely to produce perio problems
Class V Preparation
For abrasion
(2)
◦ Conservative extension
◦ May need minimal to no preparation
- Patient already prepped tooth with toothbrush
Hydrodynamic Theory of dentin sensitivity
(2)
◦ Pain caused by dentinal fluid movement
◦ From mechanical or chemical stimuli
- Temperature changes
- Air drying
- Osmotic pressure
Causes of tooth sensitivity
(7)
Caries or leaky restoration
Void- fluid flows into void
Premature occlusion
Exposed dentin
Exposed cementum
Post- perio surgery
Abrasion and erosion
Void- fluid flows into void
◦ Ex.
From CaOH liner having washed away
Exposed dentin
◦ Recession or incomplete formation of CEJ
Abrasion and erosion
◦ Includes
iatrogenic from polishing instruments
Treatment options- sensitivity
Aim is to
— first
occlude tubules to stop fluid movement
NONINVASIVE
NONINVASIVE first
(4)
◦ Topical fluoride
◦ Desensitizing dentifrices (toothpastes)
◦ Desensitizing agents
◦ Resin desensitizers
If none of that works=
restoration
Treatment:
Fluoride Varnish
5% NaF (Duraphat) varnish 22,600 ppm fluoride
◦ not approved for use by FDA as caries preventive but ok for desensitization. (Has been used in Europe for many years)
Fluoride varnish is a sticky, yellow, semi-liquid containing 5% NaF in a resin base mixed with alcohol to dry quickly after application.
Four manufacturers market the varnishes under the names. (Duraphat, Cavity Shield, Durafluor, and Fluor Protector)
Apply carefully – material sticks to lips and face.
◦ Use disposable application instruments because it bakes on instruments during sterilization and is difficult to remove.
Treatments- fluoride toothpaste,
trays
(2)
Prescription toothpastes
Fluoride trays
- Wear overnight
Treatments: Desensitizing Dentrifices
- Toothpaste
Toothpastes - may take 1-3 months for results to
be realized.
Sensodyne (Block Drug Company) Strontium
chloride 10% and Potassium Nitrate (KNO-
gunpowder)
Most brands make a Potassium Nitrate
sensitivity toothpaste
Gluma
◦ Placed by dentist when preparing tooth
(5)
◦ place after etching (for composite restorations)
◦ Lightly dry
◦ Place bonding agent
◦ Place composite
◦ Can also be used with amalgam, but fewer steps
When to restore vs. when to leave
(4)
Esthetic desire of patient
Lesion >1.0mm depth and progressing
Possible pulp exposure
Structural integrity of tooth is threatened
Treatment- restoration Will block tubules
(3)
◦ Amalgam
◦ Composite
◦ Glass Ionomer
Treatments- why they work
(6)
Protein coagulation
Enzyme interference, blocking nerve impulses
Induction of tertiary dentin
Various precipitates in dentinal tubules block fluid movement
Destruction of odontoblasts
Placebo effect (40% of patients respond to application of distilled water)
