3. Porcelain Laminate Veneers

____ are the 1st string for rebuilding aesthetic smiles

Porcelain Laminate Veneers (PLV)

Primary use of PLVs

changing color and morphology of anterior teeth

What are some limitations of LPV’s

• occlusion

• designs and marginal placement

• quality of enamel

PLV indications

1. Discoloration resistant to bleaching

   1. Tetracycline = most common

2. Modification of ant teeth

   1. Diastemas, cone teeth, length

3. Rehab of ant teeth

   1. fractures, congenital, malformations

Position and character of the _______ of central incisors/canines will determine the esthetics, phonetics, occlusal plane, anterior guidance and stability of the occlusion

incisal edges

PLV is best evaluated by a ________

diagnostic wax up

Why is prognosis poor on severely worn teeth?

• marginal placement = critical

• need adequate space for porcelain

Basic principles of PLV Preps

• Smooth uncomplicated preparation

• 0.3 - 0.5 mm enamel reduction...in 2-3

  planes

• Smooth, adequate margins, soft

  chamfer.

• Total margin in enamel

• Path of insertion from facial if possible

• Incisal edge covered with 1-1.5 mm of porcelain for esthetics and function

• Keep the tooth/veneer margin away from opposing incisal edges during maximum intercuspation

• The incisal preparation may or may not wrap to the lingual

PLV Prep Steps (3)

1. reduce incisal edge by 1-1.5 mm if needed

2. prepare facial surface in 2-3 planes, (if needed) remove an equal amount of tooth structure as determine by your diagnostic workup

3. define margins of the preparation and refine the margins with magnification to make them smooth

Depth orientation grooves at

1. Inicial/body

2. Gingival

Best burs?

1. 0.5

2. 0.3 mm

best burs: 1mm chamfer, Brassler-LVS1 (0.5mm) or LVS2 (0.3 mm) 3-wheel diamond depth cutter

Chamfer should be near the

gingival

T/F always break contact for PLVs

False

* depends

It is best to keep occlusal centric strikes _____ from restoration junction at lingual enamel

1 mm or more

advantages of an incisal overlap

1. Porcelain is stronger in ___ vs ______

2. Slight covering provides _____, aids in proper seating of veneer

3. Stress concentration of veneer diminishes, wide vertical stop to resist __________

1. compression vs tension

2. Vertical stop

3. Vertical loading

PLVs should be prepared in ____ planes on the facial surface.

\
List them

\
The purpose is that it allows for ___ path of insertion

3

1. Emergence

2. Midfacial

3. Incisal

Facial

• Bonding is stronger when enamel rods are 90 degrees

What are some historical uses of provisionals? (5)

1. to protect the prepared teeth

2. as an esthetic replacement of teeth

3. to check occlusal function and stability

4. to keep the periodontium healthy

5. to evaluate phonetics and esthetics

T/F Digital impressions are great for PLVs

False - questionable

Best materials for PLV impressions

Polyether or Polyvinyl siloxane

What are some things that can effect shade selection?

1. Viewer

2. Shade guide/stump shade

3. Variable lighting

____ is critical to success of PLVs

Dry field isolation

1. The lab should apply the _____ before it come to you

2. Ideal to apply silane coupling agent before ____ this protects the etched surfaces during try-in and adjustment

3. Silane should be reapplied prior to ____

1. hydrofluoric acid

2. try in

3. cementation

____ is responsible for allowing HFA etching

Leucite

___coupling agents are thought to be active, forming ___ bonds with __ on the porcelain surface and increasing adhesion with ____

Silane

\
siloxane bonds with OH groups

\
porcelain surface and

\
composite

Silane should be exposed to porcelain for ______ *with a minimum of* ______

1 min

30 sec

Silanation of porcelain before try-in seems to ______ the highly sensitive etched porcelain

protect and seal

Why is it important to properly store silane?

• Improperly sealed containers cause rapid evaporation of solvents

• Abused silane may act as a separating medium \n

Describe bonding protocol:

1. Teeth are etched with __ phosphoric acid for secs and rinsed with water for at least as long as ____

2. Dry, according to manufacturer’s instructions...new generation agent

3. If dentin is exposed follow bonding protocol:

4. Apply unfilled resin to veneer

5. Apply selected shade of luting agent to the

   veneer and press gently onto the tooth

6. Carefully, remove expressed luting agent at the margins... photopolymerize with 5 mm tip for ___ secs remove cement with surgical blade with #12 or #15,

7. __ sec cure, wait for 20 sec,

8. then cure for __ min

1. 37%, for as long as it was etched

2. do not light cure unfilled resin (bonding agent)

3. 3 secs,

4. 20 secs

5. 1 min

Describe finishing steps

1. Remove excess cement w composite finishing knife, #12, or #15

2. Finish w diamond paste and polishing cups OR felt wheel if needed

why should you not use diamonds/carbide finishing burs on PLVs

they can ditch and deglaze surface

You can expect about ___ of anterior papilla filla from crest of bone to the tip of papilla

5 mm

what is the most common error submitted to labs?

insuff facial reduction

Increased fracture of porcelain when extending incisal edge more than ___

0\.5mm

at 5 years what was a common issue reported w PLVs?

Most had washed out luting agent at the margins, especially the gingival

\
even with dentinal bonding agents (always end in enamel)

Microleakage is assoc’d w what 2 things?

Dentinal bonding

\
lack of enamel

Describe each of the types of fractures

• Static fracture line

• Cohesive fracture

• Adhesive Fracture

• Static fracture line – fracture lines present but veneer intact on tooth

  • (composite shrinkage and fatigue/occlusal loading)

• Cohesive fracture – incisal edge and gingival third

  • (tensile force related, similar to abfraction related, flexing of teeth

• Adhesive failure – usually where not enough enamel is present or technique related failure

An _______ can be used to reduce failure

occlusal

1. Porcelain has been around for more than __ years in restorative dentistry

2. ___ Faunce and Meyers first described a laminate veneer restoration for incisors. The

   porcelain was etched and bonded to enamel

1. 100

2. 1976

avg life of PLVs

10-12 years

Best chance for success is a fully equilibrated, __________

occlusion...particularly for lateral and protrusive excursions \n

mutually protected

____ zone of enamel for best bonding of veneer to tooth structure

360 degree

Ideal Reduction Guidelines

1. Incisal

2. Ging margin

3. Facial

4. Planes

1. 1-1.5 mm on incisal edge (if needed)

2. 0.3 mm chamfer at gingival margin

3. 0.5 mm reduction on most of facial surface

4. 2-3 planes on facial surface

Path of insertion should be from ______

Facial Incisal

\
\

When should contact be broken w LPVs

is diastema present

amount of reduction influenced by _____

diagnostic wax-up

Compare LPV materials

1. Feldspathic porcelains

2. Pressable ceramics

3. Pressable ceramics

1. Feldspathic porcelains – hand stacked

2. Pressable ceramics –

   1. Empress – leucite crystals help stop propagation of micro cracks.

   2. The occlusal wear of Empress is in the range of enamel.

   3. Weakest of pressable ceramics but most natural and translucent.

   4. It will not block out dark tooth structure

3. Pressable ceramics – E-Max (lithium disilicate) – combines high strength with high esthetics.

   1. More opaque than Empress.

   2. Wear about equal to enamel.

   3. Can be adhesively or conventionally cemented

_____ failures can occur at any time over life of restoration.

Can occur in first few months when traumatic forces are present, or contamination occurred at insertion

Cohesive

T/F? Microleakage can sometimes be repaired but depends on area involved and how much

True