Transcript Faculty of Dentistry National University of Singapore

Veneers
Faculty of Dentistry
National University of Singapore
Founded 1905
Dr Charles Pincus
“ The development of dental
aesthetics in the motion
picture industry ”
Journal of the California Dental
Association 1938
Faculty of Dentistry
National University of Singapore
Founded 1905
Veneers ( Pincus )
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thin facings of
air-fired porcelain
temporarily held
in place with
adhesive denture
powder
Faculty of Dentistry
National University of Singapore
Founded 1905
Veneers
Direct
(resin)
CAD - CAM
Indirect
preformed
(acrylic)
Faculty of Dentistry
National University of Singapore
Founded 1905
custom lab
fabricated
(resin, ceramic)
Direct resin bonding
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advantages
 can be completed in 1 visit
 under the control of the operator
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disadvantages
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susceptibility to staining
poor wear and abrasion resistance
time consuming
prone to chipping
Faculty of Dentistry
National University of Singapore
Founded 1905
Indirect veneers
 one-piece acrylic resin
prefabricated veneer ( Faunce 1970)
 laboratory formed microfill resin
veneers
 chemical primer applied to veneer
 composite resin to lute the veneer
to etched tooth
Faculty of Dentistry
National University of Singapore
Founded 1905
Indirect prefabricated acrylic and
lab formed resin veneers
• display greater anatomical
accuracy
• less chairside time for dentist and
patient
• less polymerization shrinkage
• better shading capabilities
• more control of facial contours
• more stain resistant
Faculty of Dentistry
National University of Singapore
Founded 1905
Indirect veneers
Prefabricated acrylic and laboratory
formed microfill resin veneers
 poor resistance to abrasion
 tendency to delaminate at the
laminate/composite interface
 limited to cases not involving
heavy functional contacts
Faculty of Dentistry
National University of Singapore
Founded 1905
Indirect Veneers
Porcelain
 long history of use of porcelain
 9th century Chinese
 1700 France and England used
refined porcelain for dinner
plates and artistic objects
Faculty of Dentistry
National University of Singapore
Founded 1905
Porcelain
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18th century
Alexis Duchateau
Parisian apothecary
fabrication of
denture bases
Faculty of Dentistry
National University of Singapore
Founded 1905
Porcelain
• Dubois de Chemant
• patent to manufacture
porcelain denture teeth
• 1449 – Dentist’s Supply
Company of New York
 process for vacuum-firing
porcelain teeth
Faculty of Dentistry
National University of Singapore
Founded 1905
Porcelain Veneers
Technique
bonding of thin porcelain laminate
to tooth surface using adhesive
techniques and a luting composite
to change colour, form and/or
position of (anterior) tooth
Simonsen & Calamia 1983
Faculty of Dentistry
National University of Singapore
Founded 1905
Porcelain veneers
Advantages
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dimensional stability
insolubility in oral fluids
excellent aesthetics
tissue tolerance
high wear and abrasive resistance
longevity
Faculty of Dentistry
National University of Singapore
Founded 1905
Insolubility in oral fluids
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more resistant to deleterious
effects of solvents eg alcohol,
medications and cosmetics than
resin veneers
Sheth and Jensen 1988
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much less absorption of fluids than
any other veneering materials
Garber 1989
Faculty of Dentistry
National University of Singapore
Founded 1905
Excellent aesthetics
 natural and stable colour
 optical refractive properties similar to
enamel
 can be intrinsically and extrinsically
stained
 texture easily developed and maintained
 retains its glazed lustre over the life of
the restoration
Faculty of Dentistry
National University of Singapore
Founded 1905
Tissue tolerance
• extremely good biocompatibility with
gingival tissues
• less depository areas for plaque
accumulation
Olsson et al 1992
• plaque removed more rapidly from
porcelain surfaces
Hahn et al 1993
Faculty of Dentistry
National University of Singapore
Founded 1905
Physical and mechanical properties
Acceptable tensile bond strength
resin lute – porcelain veneer
resin veneer – enamel
2600 – 3200 psi
900 – 1400 psi
Calamia and Simonsen 1984
Faculty of Dentistry
National University of Singapore
Founded 1905
Physical and mechanical properties
Inherent porcelain strength
 allows reshaping
 porcelain veneers fragile, once
cemented develops high tensile and
shear strength
Calamia 1983
Faculty of Dentistry
National University of Singapore
Founded 1905
Physical properties
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exceptional resistance to wear and
abrasion
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still looks good after many years
resistant to stain
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microscopic structure reveals few
voids and irregularities
glazed surface
Faculty of Dentistry
National University of Singapore
Founded 1905
Disadvantages of porcelain veneers
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time
difficult to repair
technique - sensitive
colour
irreversible procedure
Faculty of Dentistry
National University of Singapore
Founded 1905
Disadvantages of porcelain veneers
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susceptibility to pitting
difficulty in resurfacing and
polishing glazed surface
fragility
cost
Faculty of Dentistry
National University of Singapore
Founded 1905
Indications for porcelain veneers
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discolorations eg tetracycline,
devitalisation, fluorosis, aging,
amalgam shine-thru’
enamel defects eg. aging, cracks,
trauma
diastemata - single or multiple
malpositioned teeth
malocclusion
Faculty of Dentistry
National University of Singapore
Founded 1905
Indications for porcelain veneers
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extensive anterior restorations
short teeth
agenesis of the lateral incisor
progressive wear patterns
anterior guide rehabilitations
Faculty of Dentistry
National University of Singapore
Founded 1905
Contraindications
Available enamel not present
 should be enamel around the whole
periphery of the veneer –
for adhesion and seal
 optimal bond to enamel
Troedson and Derand 1998
Faculty of Dentistry
National University of Singapore
Founded 1905
Contraindications
Bond of porcelain to dentine
 use of newest generation of DBA
the bond strength of porcelain bonded
to enamel
dentine
> porcelain bonded to
Van Meerbeek et al 1996, 1998
Faculty of Dentistry
National University of Singapore
Founded 1905
Contraindications
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ability to etch enamel
 excessive fluoridation
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oral habits
 bruxism, pencil chewing or ice-crushing
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occlusion
 class 3 or end-to-end bite
Faculty of Dentistry
National University of Singapore
Founded 1905
Porcelain veneers
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shade selection
tooth preparation
impression
temporisation
laboratory procedures
placement
insertion
finishing
post insertion instructions and
maintenance
Faculty of Dentistry
National University of Singapore
Founded 1905
“ ….. patients may not always
know just what they want, but
they certainly know what they
do not want ”
Faculty of Dentistry
National University of Singapore
Founded 1905
TOTAL TEAMWORK
IN
AESTHETIC DENTISTRY
Faculty of Dentistry
National University of Singapore
Founded 1905
Shade selection
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select at the beginning of treatment
use colour corrected lighting and in
daylight
use of opaquer?
single / multiple teeth
refer to lecture on shade taking
Faculty of Dentistry
National University of Singapore
Founded 1905
Tooth preparation
To reduce
or
not to reduce
?
Faculty of Dentistry
National University of Singapore
Founded 1905
Tooth reduction
• early concepts – minimal or no
preparation
 led to gingival irritation, overcontouring
and high failure rates
Shaini et al 1997
Hahn et al 2000
• current beliefs support removal
Calamia 1985
Garber 1987
Nixon 1990
Friedman 1991
Faculty of Dentistry
National University of Singapore
Founded 1905
Tooth preparation – Rationale
• adequate dimension for porcelain
• remove convexities and provide path
of insertion
• space for opaquing and resin cement
• definite seating
• receptive surface for etching
• facilitate sulcular margin placement
Faculty of Dentistry
National University of Singapore
Founded 1905
Enamel reduction – contraindications
• size of pulp
• patient’s psychological
state
Faculty of Dentistry
National University of Singapore
Founded 1905
Tooth reduction – how much?
• degree of discolouration
• should remain within enamel
wherever possible and especially at
the margins
• relative teeth position
• ceramist’s difficulty working with a
thin veneer
Faculty of Dentistry
National University of Singapore
Founded 1905
Tooth reduction
• 0.5 – 0.75 mm to allow for
thickness of porcelain
Christensen 1991
• problem with cervical margin –
usually encroaches onto the
dentine
Ferrari et al 1992
Faculty of Dentistry
National University of Singapore
Founded 1905
Average thickness of enamel
on central incisor
Faculty of Dentistry
National University of Singapore
Founded 1905
Tooth preparation
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labial
interproximal
sulcular
incisal/occlusal
lingual
Faculty of Dentistry
National University of Singapore
Founded 1905
Sulcular preparation
microleakage increases with
• presence of aprismatic enamel
Peumans et al 1999, Tjan et al 1989
• prep encroaches on dentine
Zaimoglu and Karaagaclioglu 1991
Faculty of Dentistry
National University of Singapore
Founded 1905
Incisal preparation
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window or intra-enamel
overlapped incisal edge
feathered incisal
Faculty of Dentistry
National University of Singapore
Founded 1905
Tooth preparation
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depth guide
hide margins in embrasure areas
place gingival margin
 supragingival
 just into the gingival sulcus
Faculty of Dentistry
National University of Singapore
Founded 1905
Finish line configuration
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feather edge
rounded shoulder
chamfer  able to accommodate adequate
porcelain
 proper seating and accuracy of
fit
Faculty of Dentistry
National University of Singapore
Founded 1905
Impression
Tissue management
 use of retraction cord to displace
gingival tissues
 cord – haemostatic agent?
 healthy gingival tissues
 removal of cord? If yes, remove
wet.
Faculty of Dentistry
National University of Singapore
Founded 1905
Impression
• polyvinylsiloxane – light and
heavy/ medium viscosity
• insert from buccal oblique
direction
Faculty of Dentistry
National University of Singapore
Founded 1905
Temporization
Unnecessary
 only enamel exposed
 minimal sensitivity and
aesthetic concerns
 may irritate gingiva
Faculty of Dentistry
National University of Singapore
Founded 1905
Temporaries – indications
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reduction exposing dentine
problem of sensitivity
open contacts allowing movement
of teeth
mandibular teeth with incisal
reduction
problem of aesthetics
Faculty of Dentistry
National University of Singapore
Founded 1905
Temporization – techniques
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Direct techniques
 composite veneer
 composite resin using vacuform matrix
 acrylic resin
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Indirect
 composite resin
 acrylic resin
Faculty of Dentistry
National University of Singapore
Founded 1905
Temporaries - attachment
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spot etch
and/or unfilled bonding agent
ensure that the periphery of the
preparation is not involved or
compromised by etching
Faculty of Dentistry
National University of Singapore
Founded 1905
Laboratory Procedures
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a good impression
bite registration
cast of opposing arch
shade selection
photograph ( optional )
Faculty of Dentistry
National University of Singapore
Founded 1905
Laboratory Techniques
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Refractory investment
Platinum foil
Faculty of Dentistry
National University of Singapore
Founded 1905
Refractory investment technique
• porcelain fired directly on a
refractory die material
• preferred technique
Wildgoose et al 1997
Faculty of Dentistry
National University of Singapore
Founded 1905
Platinum foil technique
• porcelain fired over a 0.001inch thick platinum foil matrix
• uses individual removable dies
on a master cast
Faculty of Dentistry
National University of Singapore
Founded 1905
Porcelain application
• use of opaquer ?
• built in layers
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gingival third
body
incisal
enamel
• finishing and contouring
Faculty of Dentistry
National University of Singapore
Founded 1905
Colour management characterization
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colour changes must be made in
the porcelain itself
communicate using photos
if colour not satisfactory during
try-in , it is difficult to change
Faculty of Dentistry
National University of Singapore
Founded 1905
Etching of veneers (Lab)
etching inner surface with
hydrofluoric acid and silanizing
etched surface increases bond
strength of a resin lute to etched
enamel
Stangel et al 1987
Nicholls 1988
Faculty of Dentistry
National University of Singapore
Founded 1905
Hydrofluoric acid on porcelain
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dissolves glass
components
creates micropores
and porosities
Peumans et al 1999
Stangel et al 1987
Yen et al 1993
Faculty of Dentistry
National University of Singapore
Founded 1905
Etching of veneer
Using hydrofluoric acid
 amorphous micro-structure with
numerous porosities
 increase surface area for bonding
 micro-mechanical interlocking of
the resin composite
Stangel & Nathanson 1987
Faculty of Dentistry
National University of Singapore
Founded 1905
SEM micrograph (magnification X 1000 )
unetched porcelain
Faculty of Dentistry
National University of Singapore
Founded 1905
etched porcelain
Etching of veneer
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etching gel – 7.5% hydrofluoric acid
follow manufacturer’s directions
 etching time
 concentration of etchant
 type of porcelain
Faculty of Dentistry
National University of Singapore
Founded 1905
Silane
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chemical coupling
agent between resin
and porcelain
improves wettability
increases adhesion
decreases
microleakage
Jackson 1994
Faculty of Dentistry
National University of Singapore
Founded 1905
Placement
Try –in
 each
individual
veneer
 collective fit
 assess colour
Faculty of Dentistry
National University of Singapore
Founded 1905
Fit
• clean teeth
• veneers are extremely fragile
• place a drop of glycerine or
water
• passive fit
Faculty of Dentistry
National University of Singapore
Founded 1905
Cementation
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veneer
tooth surface
Faculty of Dentistry
National University of Singapore
Founded 1905
Colour check
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colour dependent on
 tooth
 porcelain
 composite resin
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use of try-in pastes
Faculty of Dentistry
National University of Singapore
Founded 1905
tooth - RESIN - ceramic
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interface between veneer and
tooth surface
weak link in the system
allow for slight modification of
colour
Faculty of Dentistry
National University of Singapore
Founded 1905
Try in pastes
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avoid exposing resin to operating
light
remove try-in paste by placing
veneers in a container of 95%
alcohol, acetone or distilled water
in an ultrasonic bath
Faculty of Dentistry
National University of Singapore
Founded 1905
Composite Resin Cements
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light curing
chemical curing
dual curing
Faculty of Dentistry
National University of Singapore
Founded 1905
Resin luting agents
• diacrylate resins
• particle size : 0.5 - 15 microns
• filler loading : 20 - 75 %
inorganic particles
• particle type : silica or glass
• mostly hybrids , some microfills
Faculty of Dentistry
National University of Singapore
Founded 1905
Composite resin cement for veneers
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a light curing composite resin is
preferred
 longer working time
 better colour stability
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ensure adequate light transmittance
 thickness of veneer
Faculty of Dentistry
National University of Singapore
Founded 1905
Thickness of veneer
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thickness of 0.7 mm - resin lute
does not reach its maximum
hardness
Linden et al 1991
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use of dual curing resin
Faculty of Dentistry
National University of Singapore
Founded 1905
Insertion of veneers
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tissue
management
lay out
Faculty of Dentistry
National University of Singapore
Founded 1905
Sequence of cementation
veneer
(etching)
silanation
tooth
prophylaxis
etched
primer
bonding agent
cementation
Faculty of Dentistry
National University of Singapore
Founded 1905
Insertion of veneers
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seating sequence – central
incisors first
rotate veneer into place with
gentle agitation
do not slide into place
check intimate contact with
explorer
Faculty of Dentistry
National University of Singapore
Founded 1905
Polymerization
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tack-cure for 5 - 8 secs
remove excess with brush
moistened with bonding resin
cure for at least 2 minutes each
 use of 2 lights – buccal and lingual
 use of 13 mm diameter light tip
Faculty of Dentistry
National University of Singapore
Founded 1905
Finishing
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after finishing of veneers, a
considerable amount of excess
cement is still present
removes
Harasani et al 1991
 marginal defects
 glaze of porcelain
Faculty of Dentistry
National University of Singapore
Founded 1905
Finishing and polishing
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finish equal or superior to glazed
porcelain ( Haywood et al 1988)
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use of a series of finishing grit
diamonds (MFS) followed
by a 30-fluted carbide bur
diamond polishing paste
polish under water spray
(Haywood et al 1999)
Faculty of Dentistry
National University of Singapore
Founded 1905
Occlusal assessment
• ensure veneers do not make
excessive contact with
opposing arch
• use of a night-guard highly
recommended
Faculty of Dentistry
National University of Singapore
Founded 1905
Directly milled
ceramic inlays and onlays
CAD-CAM systems
Computer-aided
design /computer
aided manufacture
Faculty of Dentistry
National University of Singapore
Founded 1905
CAD –CAM Systems
• Sopha Bioconcept Francois
Duret
• DentiCAD
Dianne Rekow
• Cerec
Mormannn and
Brandestini
Faculty of Dentistry
National University of Singapore
Founded 1905
Cerec System ( Siemens)
• 1985
• clinical track record
• fabrication of inlays, onlays
and veneers, ¾, 7/8 and full
crowns
• Cerec, Cerec 2, Cerec 3
Faculty of Dentistry
National University of Singapore
Founded 1905
Cerec
• preparation design
• optical impression
• computer-generated
restoration design
• milling procedure
• clinical placement
Faculty of Dentistry
National University of Singapore
Founded 1905
Celay System
(Mikrona technologie AG, Germany)
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Stefan Eidenbenz 1994
tooth preparation
impression
pro-inlay fabricated
copied and reproduced in
ceramic in a milling machine
Faculty of Dentistry
National University of Singapore
Founded 1905
Celay system
2 aspects of the milling centre
ceramic block is centred in
holder for manual scanning
rotary turbine with various
cutting tools for cutting the
replica of the plastic prototype
Faculty of Dentistry
National University of Singapore
Founded 1905
Maintenance
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immediate
long term
Faculty of Dentistry
National University of Singapore
Founded 1905
Post treatment care
First 72 -96 hours
 avoid hard foods, alcohol and
some medicated mouthwashes
 avoid extremes in temperatures
 maintain soft diet
Faculty of Dentistry
National University of Singapore
Founded 1905
Maintenance
• routine cleanings
• avoid ultrasonic scaler and air abrasion
systems
• use soft toothbrush with rounded
bristles
• floss
• toothpaste – less abrasive
• mouthrinses – avoid acidulated fluoride
rinses
Faculty of Dentistry
National University of Singapore
Founded 1905
Maintenance
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avoid bad habits – pencil chewing ,
nail biting
avoid biting hard foods
 biting crab shells
 sugar cane
 ice chewing
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use mouth guard with any contact
sports
Faculty of Dentistry
National University of Singapore
Founded 1905
Maintenance
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avoid
 staining foods and
liquids
eg tea, coffee
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intrinsic erosion –
eating disorders
extrinsic erosion
– acidic juices
and fruits
Faculty of Dentistry
National University of Singapore
Founded 1905
Failures
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most common – fracture
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modest 0 - 5% to 7 – 14%
Peumans et al 2004
Seymour et al 2001
Friedman 1998
marginal staining and leakage
Strassler and Weiner 1998
Pneumans et al 1998
 composite – tooth interface
 due to lack of enamel
 caused by chromogenic bacteria and organic stains
Faculty of Dentistry
National University of Singapore
Founded 1905
Failures
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unfavourable occlusion and articulation
significant parafunction
exposed and large dentine surfaces
partly bonded to underlying CR
1993
Dunne & Miller
Shiani et al 1997
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marginal defects – wearing out of CR lute
Faculty of Dentistry
National University of Singapore
Founded 1905
SUMMARY
“ In vitro and in vivo studies indicate
porcelain veneers are strong and
durable restorations in the medium
to long term when enough intact
tooth tissue to bond the porcelain
veneer and articulation and
occlusion are not pathological ”
Faculty of Dentistry
National University of Singapore
Founded 1905
Longevity
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short to medium-term clinical studies
(1-5 yrs) report a low failure rate
(0-5%) due to loss of bonding and
fracture
higher failure rates ( 7 - 14%) for 3 -10
years
Peumans et al 2000 (Review)
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13 - yr study : 96.4% success
Strassler 1989
Faculty of Dentistry
National University of Singapore
Founded 1905
Longevity
• 94.4 % at 12 yrs
Fradeni et al 2005
• 95 % at 5 - 6 yrs
93% at 10 -11 yrs
91% at 12- 13 yrs
Layton & Walton 2007
Faculty of Dentistry
National University of Singapore
Founded 1905
Co-variables for longevity studies
• design of preparation ?
 depth
 finishing of incisal, proximal
• occlusion
• presence of composite fillings
• materials – type of luting resin, adhesive
• method of fabrication ?
• vitality
Faculty of Dentistry
National University of Singapore
Founded 1905
Failures
Esthetics
Mechanical complications
Periodontal support
Loss of retention
Caries
Tooth fracture
Faculty of Dentistry
National University of Singapore
Founded 1905
31%
31%
12.5%
12.5%
6%
6%
“ ……….. All clinical studies
confirm the maintenance of
aesthetics of porcelain veneers
in the short, medium to long
term ”
Faculty of Dentistry
National University of Singapore
Founded 1905