Inlay, Onlay, Veneer Flashcards
Indirect restorations
(3)
- Restoration is fabricated outside of the mouth * indirectly
- Dental impression is taken of the prepared tooth,
then sent to lab or milled in-office - Includes inlays and onlays, crowns, bridges,
and veneers
When margin exceeds 2/3 of the distance between central groove and cusp tip
MUST CAP WEAK CUSPS
When margins end ½ distance between central groove and cusp tip
CONSIDER CAPPING WEAK CUSPS
INLAY
(2)
- indirect restoration that is placed within the cusp tips of a
tooth - offers no protection of the cusp from occlusal forces
Inlays are used for
(2)
*Teeth with minimal caries and strong buccal and lingual cusps
*Acceptable (normal) occlusion
ONLAY
(3)
- indirect restoration that covers one or more cusps, extending
through and beyond the cusp tip to the facial/lingual and proximal
slopes of the covered cusps - incorporates the principles and advantages of both intracoronal
and extracoronal indirect restorations - occlusion in all functional positions is supported by restorative
material rather than tooth structure
Indications for Onlays
(3)
*Large carious lesions or existing defective
restorations
*Cracked Teeth
*Endodontically treated teeth
When should we use an Onlay instead of an Inlay?
(4)
*When the bucco-lingual width of the cavity preparation is
* 1/2 way between central groove and cusp tip - consider
onlaying the cusp
* 2/3 way between central groove and cusp tip - should
onlay the cusp
*Where the cusps are undermined after caries removal
*Where the occlusion of the tooth must be altered
Crown
- indirect restoration that fully covers the occlusal
surface of a tooth and uses the external walls for
retention
Why Do we do Inlays and Onlays ?
(5)
*Preference over amalgam
*Conserve tooth structure
- Compared to full coverage crown
*Esthetics
*Removable Prosthodontic abutment
- Can better control rest seats and guide planes
Disadvantages of Indirect
Restorations
(3)
*Expense
*Requires 2 appointments if sent to a lab
*Impression needed
- either digital or with impression material
Advantages of Indirect
Restorations
(3)
*Strength of materials
*Conservation tooth structure
*Better control of restoration’s contours
Principles to follow
(2)
- No undercuts; passive fit
- No sharp line angles
Advantages of indirect gold
*Strength
* will not fracture
*Wear resistance
* will support contact and occlusion
*Will maintain smooth surface (no tarnish or corrosion)
Better control of contact and contour Especially for large proximal caries where an amalgam would not restore contact and contours
*Potential for greater longevity
*Conserves cementum and periodontal attachment versus restoring with a crown
Contraindications
*Facial or lingual caries or previous restorations
*Crown is better to restore multiple surfaces
*Need to compare the margin length with that of a crown in
some instances
*Patients with a high caries rate
MO Gold Inlay
Divergence Short walls should have a 2° divergence
* Long walls can have a 5-7° divergence
Bevel occlusal
* axial pulpal line angle
* gingival wall
*No sharp line angles
Prep criteria -
Occlusal Internal Form – — mm deep
2.0
Inlay Preparation
*Dovetail
* Prevents distal displacement
*NO reverse S
* Prep is more straight and angled
* Gold has strength at edge (amalgam does not)
Inlay Preparation
* Adequate proximal clearance
* — mm
* Smooth proximal walls
* Bevels:
* — mm at occlusal
* — mm at gingival
* — line angles
0.5mm
1.0mm
1.0mm
Axiopulpal
Bur Dimensions
(4)
*Know your bur dimensions
*Both lengths and widths
*Measure with a periodontal probe
*Use the bur as a guide when
preparing the tooth
Clinical procedure
*Occlusal depth is — mm
*Isthmus must be at least — mm wide
* decreases chance of fracture of restorative material
*No undercuts
*Pulpal walls = smooth & flat
*Facial, lingual and gingival margins should clear contacts by at least — mm
1.5 - 2.0
2.0
0.5
Clinical procedure*Facial and lingual walls must DIVERGE
*Need passive insertion and — than a 2-5 degree taper
* restoration — to preparation walls
greater
BONDS
Clearance-
the amount of
space between the teeth
Reduction-
the amount of
tooth structure removed
Depth cuts
— mm on lingual – functional cusp
— mm on facial
1.5
1.0
Principles for Gold Onlays
*Cover both facial and lingual cusps of
maxillary and mandibular teeth
* Minimum of — mm of gold to cover cusps supporting
occlusion; — mm for cusps not supporting occlusion
* Reverse bevel of — mm on cusps supporting occlusion; — mm on cusps not supporting occlusion
1.5
1.0
1-2
1/2
Exception for cuspal coverage –
maxillary tooth
*Exception for esthetics on maxillary teeth
(2)
- Do not cover the facial cusp of maxillary molar or premolar if supported
by strong tooth structure - Modified “esthetic” coverage of facial cusp if weak
Indications
*Esthetics - areas of esthetic importance for the patient
*Large defects or previous restorations
*Wide labiolingual missing tooth structure
*Teeth that require cuspal coverage
*Contours of large restorations are more easily developed in the
lab
*Indirect materials are more durable than direct for replacing
occlusion and contacts
Contraindications
- Ceramics can fracture if they don’t have sufficient bulk or
are under excessive stress - e.g. - in bruxers and clenchers
- Inability to maintain a dry field
- Deep subgingival preparations - difficult to get an
impression, difficult to finish, difficult to get good bonding
Advantages
*Improved physical properties
*Wear resistance
* porcelain wears opposing teeth the most and has the most resistance to wear
* porcelain> lab processed composite > direct resin composites in order of causes most wear and wears the least to causes least wear and wears the most
*Reduced polymerization shrinkage
* all shrinkage occurs in the laboratory, the only material that can shrink is the resin
composite cement which is used during cementation
Disadvantages
Increased cost and time Require two patient appointments and a lab bill
*Technique sensitivity - devotion to detail a must
*Ceramics (Porcelains) are brittle
*Ceramics wear opposing dentition and restorations
*Low potential for repair
*Difficult try in and delivery
Clinical procedure
*Remove old restorations
*Excavate all caries
*Undercuts are blocked out with a glass ionomer liner /base or resin composite
* Want rounded internal line angles – use round end bur e.g.. 245
* All line and point angles, internal and external should be rounded to avoid stress concentrators
Porcelain onlays
*— reduction over functional cusps
*— reduction over non functional cusps
*Bulk of Porcelain at margins – NO BEVEL
*Smooth internal line angles
*No ferrule margins
*Ceramic retention based on SURFACE AREA
*Not opposing walls
2.0mm
1.5mm
Clinical procedure
*Need adequate thickness for strength of restorative materials
*Need well defined margins
*All margins should have a — degree butt joint cavosurface angle
* to ensure marginal strength of the restoration
*No external bevels
90
Provisional Considerations
*Use —free cement
*Eugenol interferes with bonding
*Or, if you must use cement containing eugenol,
important to pumice tooth well to remove eugenol
eugenol
Try-in and cementation
*Occlusal evaluation and adjustments are delayed until
after
cementation because of the fragility of porcelain restorations
*Marginal gaps are larger than gold inlays and onlay margins
Silanation
*This step often completed by the lab
* You need to make sure, if not, do it yourself chairside
*Porcelain is acid etched with hydrofluoric acid and then silanated before
cementation with a resin cement
Instrumentation for Finishing and Polishing
Ceramics
*Medium to fine grit diamond instrument
*30-fluted carbide burs
*Rubber, abrasive impregnated porcelain polishing points
*Diamond polishing paste
* Do not want any scratches or rough spots on the porcelain or it will wear enamel
severely
3M Lava Ultimate
(4)
- 3M calls it a Resin Nano Ceramic
- Made primarily of Silinated Silica and
Zirconia nanomers - Highly Polishable
- Easy to use clinically
Vita Enamic
(3)
- Porous Sintered Ceramic structure
infused with a polymer - Highly Polishable
- Easy to use clinically
Vita Porcelain
(3)
- Highly esthetic
- Mostly used in Anterior applications now
- Flexural Strength 154 MPa +/- 15 MPa
Ivoclar Empress
(4)
*Leucite helps strengthen ceramic and can
act as a crack deflector
*Highly Esthetic
*Flexural Strength 160 MPa
*Leucite glass ceramic
Ivoclar e.max
(5)
*Lithium Disilicate Ceramic
*Starts in an intermediate phase and must
be crystalized
*Flexural Strength 360 MPa
*Shortened firing cycle may cause loss of
strength and color shift
*Multiple applications
Veneer definition-
a thin covering
* Often to hide the under layer
Veneers
*Types
(2)
- Indirect
- Most commonly Feldspathic Porcelain or Lithium Disilicate
- Direct
- Composite
Indications for Veneers
- Intrinsic Discoloration
- Tetracycline staining
- Fluorosis
- Extrinsic Staining
- Coffee
- Smoking
- Wine
- Wear Patterns
- Poor Restorations
- Diastema Closure
- Rotated and Misaligned Teeth
Contraindications
*Severely Malpositioned teeth
* Ortho may be indicated
*Denuded Dentin
*Unavailable Enamel
*Poor Oral Hygiene
Beware of highly fluoridated teeth Issues with bonding
*No primary teeth!
*Adolescents
*Pregnancy
*Oral Habits
* Bruxism
Picture From DVM360.com
Porcelain Veneers
Indications
*Good Oral Hygiene
*Good Periodontal Health
*Poor Esthetics - Something that is going to be improved
*Proper Patient Psychology
*Caries Free
*Met Dental Needs
*INFORMED CONSENT / REASONABLE EXPECTATIONS
Advantages of Porcelain Veneers
Esthetics – excellent
Color – porcelain is best tooth substitute
Bond strength – high to enamel
Periodontal health – not detrimental to it
Low wear and abrasion of porcelain restorations
Disadvantages of Porcelain Veneers
Time- Multiple appointment
Cost compared to composite veneers – ($100-150/unit)
Some tooth preparation. Must have adequate room.
Requires laboratory involvement and fee
Alternate Treatment
*Bleaching for discoloration
*Microabrasion and macroabrasion
*Direct composite veneers
* Microfill composite resin polishes best
*PFM/Porcelain jacket crown
*ORTHODONTICS
Advantages of Composite (Direct) Veneers
- Mask discolorations on a tooth
- Less cost to patient
- Usually one appointment
- Can correct simple tooth rotation and diastema easily
Disadvantages of Composite (Direct) Veneers
*Susceptible to Wear
*Margin Fracture and Stain
*Discoloration
Composite Veneer Procedure
Window Preparation
- Most often recommended
- Remove only enough tooth structure to achieve optimal
contours with final restoration - Incisal edge remains intact
- Intra-enamel preparation* necessary to provide space for materials to achieve maximum esthetics
- removes outer, fluoride-rich layer of enamel (resistant to etching)
- roughens surface for improved bonding
- establishes definite finish line
Composite Veneer Procedure
Incisal Lapping Preparation
- Preparation includes incisal edge
- Indicated when tooth needs to be lengthened or an incisal defect
is present and needs to be corrected
Some clinicians do minimal tooth preparation
which may result in — (bulky) veneers
overcontoured
Microabrasion
(2)
- Involves use of acidic and abrasive agents applied to enamel surface
- 37% phosphoric acid and pumice or 6% hydrochloric acid and silica
Macroabrasion
(3)
- Removal of enamel defect with bur
- 12 fluted carbide or diamond finishing bur, followed by 30 fluted carbide finishing bur
- Polished with rubber point
Porcelain Veneer Procedure
DIAGNOSTIC WAX UP !!!!
Very important to see
what can be
done for both you and the patient
Porcelain Veneer Procedure
PREP GUIDE
Made from wax up, tells you how much
reduction is needed to get ideal from
wax up
Porcelain Veneer Procedure
Minimal Prep needed for veneers
Try to keep prep in — for optimal bond strength
enamel
Tooth Preparation
*MINIMAL PREP VENEERS
- When minimal shade or shape change is desired
- 0.3mm chamfer at margin or slightly subgingival
- Thickness is 0.5-0.7mm on labial surface
- 1.5mm at incisal reduction
- 1-2mm reduction acceptable
- 90 degree butt joint is best
- Materials
- e.max (pressed monolithic ceramic)
- Empress (pressed ceramic)
- Feldspathic porcelain (etched porcelain)
Tooth Preparation
*MODERATE PREP VENEERS
- Moderate alignment corrections, up to 3 step change in chroma or value, diastema correction <1mm
- 0.3mm chamfer at margin or slightly subgingival
- Thickness is 0.8-1.0mm on labial surface
- 1.5mm at incisal reduction
- 1-2mm reduction acceptable
- 90 degree butt joint is best
- Materials
- e.max (pressed layered ceramic)
- Empress (pressed ceramic)
- Feldspathic layered porcelain (etched porcelain)
Tooth Preparation
(4)
– Gingival
* Terminates at the gingival crest or 0.3-0.5 sub-gingivally for esthetics
* When severely discolored enamel is present, a reduction greater than 0.5 mm may be required
* When the tooth is in lingual version, little or no reduction is necessary
* Your diagnostic wax up will guide you in the amount of reduction needed by the way of the prep guide.
Tooth Preparation
Contour the — amount necessary
according to the material that you are using to
restore the teeth
minimum
Summary of Incisal Margins
*Minimum — mm reduction for material bulk
*or — reduction of incisal if lengthening incisal edge
*Rounded at all line angles
*Butt shoulder on incisal
*No undercut between lingual and gingival
1.0 -2.0
NO
Tooth Preparation
Why no lingual margin?
(4)
Seating issuesLingual margin failure from inadequate porcelain thicknessPorcelain needs bulk when loadedIncisal butt margin preferred
Tooth Preparation
(2)
*Margins should be well-defined
*Provide a definite finish line for
technician
Porcelain Veneer Procedure
* — with a temporary material
* such as Dentsply Integrity
* Use — as matrix to fabricate provisionals
Provisionalize
wax up
Veneer Insertion
Remove provisional and clean prep with
nonfluoridated pumice
Clean interproximal lightly with finishing strip
*Isolate with rubber dam and sometimes
retraction cord
*Etch teeth with 37% Phosphoric Acid
* if in enamel for 30 seconds
* if in dentin for 15 seconds
*Place bonding agent
* Use bonding agent recommended for your
composite cement
*Tack cure in order to clean cement from margin
Remove excess cement very carefully much more difficult to remove excess cement
*Following removal of excess cement, LIGHT CURE full amount
of time
* From buccal and lingual
Veneer Insertion
Polish and Check Occlusion
(3)
*Adjust occlusion after veneers have been
bonded
* fracture more likely otherwise
* use diamond bur and water spray
CAUTION
DO NOT — veneers when polishing
Excess heat may cause degradation of cement bond
OVERHEAT
