By : Menna Allah Ashraf

Department of fixed prosthodontics

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Laminate veneers Abstract:

Esthetics have been a matter of concern in our age and also

the conservation of tooth structure which we call “tooth

banking “has been a matter of importance for all dental

practitioners.

Changing trends and treatments for dental disease have

made it necessary to diversify dental services.

Introduction of laminates as an effective esthetic

alternative has overtaken all the conventional options and

most importantly its conservative approach towards its

preparation will always make a sensible dentist to think

before going on to any alternative esthetic procedure.

This review gives an insight about the scientific definition,

evolution and spread, types, indications,

contraindications, advantages, and disadvantages of the

laminates, as an effective esthetic restoration.

Also, my research will include specific information about

porcelain veneers its features and its different

preparations because porcelain veneers are the most

commonly used, most successful, most esthetic and they

are of prime concern in fixed prosthodontics.

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Laminate veneers Introduction:

What are laminate veneers?

Dental laminate: is a wafer-thin shell (0.3-0.7 mm) usually made of

porcelain that is bonded onto the front side of teeth figs (1 & 2)

Nowadays, laminate veneers have widely spread and have been of

great importance in different uses like smile design, correction of

malformed or disfigured tooth and also they are used to hide

chipped and discolored teeth. Veneers also are very famous

between celebrities as many Hollywood celebrities have applied

veneers on their teeth to mimic more natural and pleasant

appearance (fig 1 & 2 ).

Also, laminate veneers are used in children. They are used to

replace the traumatic injuries in the teeth of the school children.

Fig 1 : laminate veneers

maintain beautiful smile Fig 2 : translucency of laminates.

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Both Laminate veneers and crowns have esthetic purpose but a

crown involves most surfaces of the tooth or all of it and requires

more tooth reduction.

Objectives:

1) Advantages and disadvantages of laminate veneers. 2) Indications and contraindications of laminate veneers 3) Types of laminate veneer their advantages and disadvantages. 4) Porcelain laminate veneers : features and preparations.

Advantages of laminate veneers: 1) Restoration of natural color, shape and translucency of

tooth 2) Good fixation because of adhesive system. 3) Conservative preparation. 4) Alternative to full coverage restoration in case of incisal

fractures and tooth discolouration. 5) Color stability.

Fig3 : advantages of laminates Fig 4 : advantages of laminates

re

r

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Disadvantages of laminate veneers : 1) More time is required than direct restoration, more laboratory

work, several appointments (time-consuming). 2) Impossible to change the color of laminate after cementation. 3) Laminates are much more expensive than fillings. 4) Brittle margins. 5) Cannot be repaired easily 6) Can sometimes be difficult to temporize 7) Difficult to finish (especially margins of porcelain). 8) Placement is difficult. 9) Potential for over-contouring.

Indications of laminate veneers:

Veneers can be used for functional and cosmetic Correction of the following conditions: 1) Stained or darkened teeth as in fluorosis and tetracycline staining. 2)Hypocalcification. 3) Multiple diastemas (fig 5 & fig 6 ). 4) Peg laterals or disfigured teeth (fig 6) 5) Chipped or fractured teeth. 6) Misaligned teeth; if a person's misalignment isn't too severe, (instant orthodontics).

Contraindications:

1) Abnormal bite. 2) Bruxism. 3) Highly destructed tooth ( if more than 60 % of the enamel is

highly destructed as the enamel thickness is necessary in bonding ).

4) Deep discoloration extending to dentin. 5) Very large diastemas.. 6) Severely malposition teeth. 7) Unfavorable wear pattern.

Teeth that have lost a significant amount of structure due to wear, decay or fracture, and those that have large fillings don't make good candidates..

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8) patients with existing compromised periodontal condition and high plaque index are poor candidates for such restorations.

9) Endodontically treated teeth: a full veneer crown would hold the integrity of the non- vital tooth better than a laminate veneer.

Fig 5 : indications of laminates ( diastema

closure )

Fig 6 : indications of laminates

( disfigured teeth and diastema closure )

Fig 7 difference between porcelain and

composite veneers in esthetics.

Fig 8: upper figure is ( composite

veneered teeth ) lower figure is

porcelain veneered teeth )

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The following table includes different types of veneers their general

advantages and disadvantages :

veneers

Advantages Disadvantages

Direct composite veneer

-Available for all dentists - Conservative. - High esthetics - Excellent gingival reply. - Easy reparation - Acceptable price

-T - Technical difficulties -Requires experience -Unsuitable for highly discolored teeth.

Indirect porcelain veneer

-Conservative. -Excellent esthetics -Very good gingival reply. (fig 7 & 8)

-Requires two appointments - Requires more preparation -Technical difficulties. - Difficult reparation. - High price.

Direct-indirect composite veneer

-Conservative. -High esthetics - Excellent gingival reply. - complete polymerization - Easy reparation - Acceptable price.

- Requires technical skills. - Requires prolonged time. - Requires extra appliances.

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Veneers can be placed directly or indirectly. Composites are used

for directly placed veneers, and a variety of ceramic materials can

be used for indirectly placed veneers.

These include:

1. Conventional powder-slurry ceramic (Feld spathic porcelain). This type of porcelain is layered on the refractory die by the lab technician. ( fig: 9 )

2. Heat-pressed ceramic: These products are melted at high

temperatures and pressed into a mold created using the lost-wax

technique (castable porcelain)

3. Machineable (CAD/CAM) ceramics (fig 10 ).

Creating lifelike ceramic veneers has been difficult skill reserved

for great ceramists using Feld spathic porcelain or meticulous

waxers using the hot press technique, but now CAD/CAM is giving

technicians the ability to easily create veneers with a few clicks of

a mouse.

Fig 9 : porcelain layered on

refractotry die.

Fig 10: Designing laminates using

(CAD/CAM).

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Any deviation from this design can result in numerous problems

with acceptance, aesthetics, phonetics and function.

Small details and surface characteristics can be improved and

minor design changes can be made to improve the artistic and

aesthetic.

The ZFX System has the ability to adapt the design to fit or

duplicate the wax-up scan exactly With conventional techniques,

this duplication was difficult to achieve; wax injection into

silicone putties made from the diagnostic wax-up can create exact

duplication but this is still time consuming and technique

sensitive.

Now with the click of the mouse duplication is achieved. The

shapes are minimally altered to ensure proper contacts,

embrasures and interdental spaces ( fig 11 & fig 12 )

Fig 11 : CAD / CAM design anteriorly Fig 12 : CAD/CAM design laterally

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Features of porcelain laminates :

Advantages of Porcelain Laminates over other laminate systems:

Porcelain as a replacement for unaesthetic tooth substance has

been used for the following reasons:

. Color stability: There is a dual fold advantage, as porcelain offers

better inherent color control and a natural look as well as the

ongoing stability of these colors.

· Bond Strength: The bond of the etched porcelain veneer to the

enamel surface along with the silane coupling agent is

considerably stronger than other veneering systems.

· Periodontal Health: because of the highly glazed porcelain

surface, there is less depository area for plaque accumulation as

compared to other laminate systems.

Another advantage of this system is the option of placing

supragingival margins (can be placed 0.5 mm above the gingival

margin).

.Resistance to abrasion: The wear and abrasion resistance is

exceptionally high compared to composite and acrylic resins.

· Inherent Porcelain Strength: The veneer itself is rather fragile,

but once it is luted to enamel, the restoration develops high

tensile and shear strengths. The cohesive strength of porcelain is

considerably greater than the bond between resin particles and

filler in a composite resin.

· Resistance to fluid absorption: Porcelain absorbs fluids to a

lesser degree than other laminate veneering materials.

· Esthetics: there is a greater possibility to control color and

surface texture with ceramic than other materials.

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Porcelain can be stained both internally and superficially giving

vitality to the restoration. Texture can be developed on the veneer

surface to simulate that of adjacent teeth

· Conservation of tooth structure: most of the preparations have

their margins on enamel (depth of reduction between0.3 -0.7mm),

with / without involving the incisal edges)

· Transmission of light: porcelain allows transmission of light

which gives a naturalistic appearance. Ceramic buildup done by

layering or lateral segmentation can reproduce all the

characteristics' of natural enamel, like cracks, fissures and

opalescence.

· Disadvantages of Porcelain Laminates:

· Time: The placing of Veneers is technique sensitive and therefore

time consuming.

· Repair: The veneers cannot be easily repaired once they are luted

to enamel. Removal of the restoration will require grinding it off

the tooth surface

· Technique Sensitive: the entire procedure is to be followed in a

sequential manner Carelessness at any stage can have a

disastrous outcome.

· Change of shade: It is difficult to modify color once the veneers

are luted in position on the enamel surface.

· Tooth Preparation: Some tooth preparation may be required to

prevent potential problems associated with over contouring.

· Fragility: The veneers are extremely fragile and difficult to

manipulate.

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· Cost: The dental fee for a porcelain laminate can generally be

equal to even more than the normal fee for an anterior full crown.

· Color of the luting agent: restoration will be a failure if it does

not coordinate with the shade of the restoration Thickness of the

luting agent is also a determining factor.

· Post firing modifications: modification after the firing procedure

will not be possible

· Time required for Temporization: if temporization is required the

procedure is time consuming.

There are 2 types of porcelain laminate veneers:

1) Conventional porcelain veneers (fig 13) 2) LUMINEERS (fig 14 )

1) conventional porcelain veneer:

They are veneers with various preparation shapes, techniques and

they have different styles according to smile design.

Fig 13: conventional porcelain

veneer

Fig 14: LUMINEERS

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steps of conventional porcelain laminate preparation:

1) Case report: example for a patient suffering from:

Wear of the central incisor edges creating a flat anterior occlusal

plane.

Discolouration and marginal staining of the existing composite

restorations.

2) Impression for study models/bite registration record.

3) Radiographs/photographs.

4) Shade selection (fig 17 and fig 18 ).

Fig 11 : conventional porcelain veneers

Fig 15: lateral view of preoperative smile Fig 16: frontal view of preoperative smile

Fig 17: shade selection Fig 18 : shade guides

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5)Visualization: The first step in this visualization process is the

diagnostic wax-up this wax-up should be highly indicative of the

final result (fig 19 & 20 ).

In the previous case : From the wax-up, it was determined that

only four veneers would be required.

silicone matrices would be used for making an intra-oral

diagnostic mock–up, a tooth preparation guide and the temporary

veneers.

An intra-oral mock up of the final proposed result was made using

Bis-acryl resin temporary resin material in a silicone matrix once

the resin had polymerized, the matrix was removed and an

aesthetic and functional analysis was made of the result.

6)Preparation: Depth Guide Cuts – Prior to preparation always examine study models in order to avoid over-reducing areas of the tooth that may be rotated or lingually inclined. Hence, the use of a reduction guide is recommended. ( fig 21 & 22)

A diamond depth cut bur can be used to discribe horizontal depth

cut grooves on the labial surface of any anterior tooth Extend

these grooves from mesial to distal, taking care not to damage the

adjacent teeth that are not being prepared.(fig22)

Fig 19: original study cast Fig 20: diagnostic wax up

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It may be necessary to angle the bur in relation to the contour of

the labial surface to achieve the appropriate depth for these guide

cuts.

The finish lineof the preparation could end gingivally or

supragingivally, approximately 0.5 mm incisal to cemento-enamel

junction (CEJ). gingival depth shouldn’t cut the cemento enamel

junction area.

Types of Veneer Preparation:

a) Window preparation :in which the veneer is taken close to but

not up to the incisal edge.(fig23&24)

This has the advantage of retaining natural enamel over the

incisal edge, but has the disadvantage that the incisal edge

enamel is weakened by the preparation. Also, the margins of the

veneer would become vulnerable if there is incisal edge wear

whilst the incisal lute can be difficult to hide ( least restricted path

of insertion).

b) Incisal Chamfer Preparation (Interlock prep) : The incisal edge

is not reduced in length.

Fig 21 : placing depth cuts Fig 22 : depth cutter or depth cut

diamond bur

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This type of preparation is done in order to preserve the natural

guiding palatal surface of the tooth, which is important as it

1) Adds an additional space for the incisal porcelain by creating a

chamfer along the facial incisal margin using the tip of a tapered

diamond.

2) This intraenamel preparation design preserves the functional

lingual and incisal surfaces of the maxillary anterior teeth,

protecting the veneers from significant occlusal stress but it has

the least restricted path of insertion. (fig25).

c) Bevel: in which a bucco-palatal bevel is prepared across the full

width of the preparation and there is some reduction of the incisal

length of the tooth. This gives more control over the incisal

aesthetics and a positive seat during try in and luting of the

veneer. The margin is not in a position that will be subjected to

direct shear forces except in protrusion. (fig26).

Fig 23 : window preparation Fig24: window preparation

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d) Incisal Butt-Joint Preparation : Prepare 0.5 mm depth cut

grooves in the incisal edge. Using the tapered diamond remove the

remaining incisal tooth structure. Then round the facial incisal

line. is indicated when an incisal defect warrants restoration (

more restricted path of insertion ) (fig 25 ).

Fig 25: incisal butt joint

preparation

Fig 26 : incisal lingual wrap preparation

Fig 25: incisal chamfer preparation Fig 26: bevel prep

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e)Incisal Lingual Wrap Preparation:

Prepare 0.5 mm depth cuts in the incisal surface of tooth. Reduce

the incisal surfacein a manner similar to incisal butt-joint

preparation.

Reduce the mesial incisal and the distal incisal corners an

additional 0.5 mm.

Then using a diamond bur, extend the incisal chamfer to the

palatal surface This palatal chamfer should be a straight line

mesial to distal.

All incisal edges should be rounded.

The lingual chamfer line on the wrap around preparation should

be above or under the centric lingual contacts to avoid occlusal

contact on the interface between porcelain and tooth structure.

Contact should be either all on porcelain or on tooth structure.

The incisal wrap prep is a popular option for several reasons: It

can be used in most patients, easily fabricated by the technician

and easily handled by the dentist due to positive seating on

delivery also the lingual wrap increase the bulk of porcelain and

prevent its shearing ( most restricted path of insertion ) ( more

mechanical retention due to extension of the restoration ) (fig 26 )

Reduction needs to be addressed in three planes with incisal,

middlethird and cervical planes.

provide a minimum of 0.3mm (feldspathic porcelain) or

0.6mm(Empress esthetic, e.max) preparation.

Labial Reduction: Using a tapered diamond,between the depth

cuts Simultaneouslycreate a chamfer ending 0.5 mm incisal to the

CEJ.

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Incisal edge reduction:

Incisal reduction : Different preparation designs have been

advocated from feather and window preparations that involve no

reduction of the incisal edge or preparation of the lingual

surfaces,to other preparations that involve a reduction of the

incisal edges ( 1.5mm).

Proximal preparation:

This preparation in the interproximal region can be made either

by stopping short of breaking the contact, or by preparing

through the contact point. Breaking the contact (sometimes

called the “slice preparation”.

Cervical margin: The cervical preparation for a veneer is

recommended to be a chamfer design with a maximum depth of

0.4mm. This allows the veneer to reproduce natural tooth

contours and not be over-contoured additional it allows simple

seating of the veneer and minimises stresses, enhancing the future

fracture resistance of the veneer (marginal integrity ,structural

durability, high esthetics) .

In the previous case The teeth were prepared with a marginal

chamfer labially and interproximally, and a butt fit margin

palato-incisally with no wrap around onto the palatal aspect

Fig 27:Canine – Incisal Chamfer

Preparation (Interlock Prep)

Right lateral incisor– Incisal Butt-joint

Preparation

Right central incisor – Incisal Lingual

Wrap Preparation

Left central incisor – Depth Cut

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Contact points were not preserved as the teeth had natural

diastema between them. This also allowed for the changing of the

tooth widths in the final restorations (fig28)

. Following tooth preparation, the final impression is made

Even though the preparation margins were the level of the

gingival margins, a retraction cord was used to allow an

impression of the tooth.

surface beyond the margins to be captured This ensures accurate

and complete capture of the entire margin and aids the dental

technician in obtaining the correct cervical profile for the

restorations. An impression was taken using a well-designed

custom tray and a single stage impression technique.

Polyvinyl siloxane impression material was used, with heavy body

material placed in the tray and light bodied material syringed

around (fig29).

The path of insertion for veneers is in the labial or incisal-labial

All undercuts and unsupported enamel in relation to this path

must be removed

silicone reduction guide ( index ) is used in order to check the

amount of reduction required .

The reduction guide is designed to evaluate the amount of

reduction at the incisal middle third and cervical third of the

tooth.

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7)Laboratory Instructions : A detailed prescription is written to

the technician.

The prescription should include:

• Teeth number and Required shade

•The type of ceramic required to make the veneers.

• If any changes in anatomy are required for the final result e.g.

increasing length.

• Make a note of any requests made by the patient

8)Temporization.

9) etching of the veneers : The internal surface of the porcelain

veneers were etched for 90 seconds with 9% Hydrofluoric Acid

Hydrofluoric etching generates a significant amount of crystalline

debris that contaminates the porcelain surface and may reduce

bond strength by 50%. To remove this debris, the veneers were

rinsed with water for20 seconds, then cleaned with 37% Phosphoric

acid (gentle brushing with microbrush for a minute), re-rinse with

water for 20 seconds and then finally immersed in 95% alcohol in

ultrasonic bath for five minutes.

Fig 28 : finished preparations Fig 29 : polyvinyl siloxane impression

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veneer surface should appear clean and have a similar

appearancetobe etched veneer surface preparation. Silane

coupling agent is then applied ( increase wetting of the porcelain).

10) Total etch technique for the preparation : using 37%

phosphoric acid.

Etching of the preparation from 10 to 15 seconds

Fig 30:Etching of the

laminate.

Fig 31 : Internal

surface of the

laminate after etching

Fig 32 : Etching of the

preparation .

Fig 33: preparation

after etching .

Fig 34 : bonding

laminate veneer.

Fig 35: adaptation of

laminate view palatal

surface.

N.B: we never start etching the preparation before try in stage and

ensuring that the restoration is seated, well fitted no marginal

thinning and ensuring that the shade selection is right.

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11) bonding and cementation of the restoration : The application of

rubber dam is recommended to achieve adequate isolation, which helps

to provide a clean, dry environment and minimises contamination from

saliva and blood . Light curing composite resin is preferred for

cementation of the veneers as they have a longer working time than

dual cure or chemically cured composites .This allows sufficient time to

remove excess composite prior to curing and thus reduces the finishing

procedures. The colour stability of light curing resin cements are much

better compared to dual or chemical cure composites. Dual cure resin

cements contain tertiary amines which may undergo long term colour

change with overall darkening and thus are normally contraindicated

with veneers due to their thin nature and translucency.

Fig 38&39 : The smile of the patient could be with different designs such as masculine ,

feminine, Hollywood, softened , functional and focus.

Fig 36: post operative smile (lateral

view) Fig 37: post operatve smile ( frontal

view)

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12) finishing and polishing :using yellow color coded finishing stones

and hand instruments ( blade #12) ( sharp carvers to remove excess

cement)

if excess porcelain is found at the margin extra fine finishing diamonds

are used .

also, disks,carbides and rubber points can be used in finishing.(fig 43 )

Fig 40 : finishing and removal of excess

cement using a blade ( hand instrument )

Fig 41: finishing and polishing using

finishing cups and finishing burs.

Fig 42: finishing tapered

stones with yellow color

code.

Fig 43 : different finishing stones

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2) No preparation veneers ( LUMINEERS ) :

What’s the difference between LUMINEERS and conventional

porcelain veneers?

The main difference is the LUMINEERS are fabricated from certain

type of porcelain (cerinate porcelain ) that’s very strong but much

thinner than laboratory fabricated veneers (fig 44 &45 )

They are very thin their thickness is comparable to contact lenses.

Advantages:

1. Painless.

2. no anesthesia.

3. Fast technique.

4. Conservation of the tooth structure.

5. No harm to the pulp and therefore elimination of post operative

sensitivity.

6. Ease of impression, because tissue management is not needed.

7. No need for provisionals.

8. Permanently whiten teeth.

Fig44 : thickness of LUMINEER Fig 45 : thin thickness of LUMINEER

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9. Bonding to enamel.

10. Longer-lasting restorations due to enamel bonding.

11. Minimal flexing stress due to bonding to enamel.

12. Higher level of acceptance by the patients, specifically patients

with dental phobia or refuse to remove sound tooth structure.

13. Excellent esthetics.

14. Resistant to permanent staining

15. Easy to clean and maintain when placed supragingivally.

16. Can be placed over unattractive crowns and bridges without

replacing them.

Disadvantages:

1. Bulky appearance.

2. Periodontal problems due to overcontouring of the veneer

(biological principles).

3. Teeth width being restored cannot be altered significantly.

4. Difficult to mask severe staining and discoloration with thin

veneers (Such as severe tetracycline staining.

Steps of preparation of LUMINEER :

There are 2 techniques for LUMINEER preparation :

1) No-Prep Technique: allows LUMINEERS to be placed over the

existing teeth without the removal of any form of tooth structure.

Therefore, anesthesia and temporaries are also not required

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2) The lumineers Minimal Contouring Technique: requires slight

modification of the enamel but never touches dentin during

LUMINEERS placement. Only .3 mm-.5 mm enamel is removed,

causing no sensitivity for the patient and therefore no need for

any anesthesia.

Steps of LUMINEERS preparation :

1. Polishing: Clean the teeth with Porcelain Laminate Polishing

Paste and rinse.

2. Refresh the Enamel: Perform minimal enamelplasty with a

prep diamond bur, using light pressure Use the whole length of the

bur keeping contact with the teeth.

3. Interdental Strips

Isolate the teeth receiving LUMINEERS from the teeth not

receiving LUMINEERS by applying Paint-On Dental Dam or

placing metal interdental strips in order to prevent etchant from

contacting adjacent teeth (fig 46).

4. Etching:

1) Etch the teeth with Etch ‘N’ Seal For 20 seconds.(fig47)

2) Rinse thoroughly with water, then dry.

5) bonding: using a bonding agent + ulrabonding agent.

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6) Insert the LUMITray:

1. Remove the Paint-On Dental Dam or interdental strips.

2. Center the LUMITray (midline).

3. Insert the tray in one smooth movement.

4. Apply light and continuous buccal pressure.

5. Remove excess resin cement from the gingiva with a

microbrush.

7) Cure LUMINEERS Through LUMITray.

8) Clean-Up and Open Interdental Spaces.

9) Remove excess cement using the finishing bur kit.

Fig 48 : insertion of laminates Fig 49: light curing through LUMI

tray

FIG 46 : isolation of teeth using

a paint

Fig 47: etching

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10 ) light curing the restoration.

Conclusion : laminate veneers are from the most popular

restoration in the cosmetic dentistry nowadays .every kind of

laminate has its own advantages and its own preparation

according to the case .

Fig 50: light curing the LUMINEER Fig 51: LUMINEERS after insertion

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References and links:

http://www.wattpad.com/23011-indications-and-contraindication-for-laminates

http://www.nature.com/bdj/journal/v189/n5/full/4800739a.html

http://www.nature.com/bdj/journal/v193/n2/full/4801489a.html

http://jonfrankeldentistry.com/veneers-and-lumineers.php

http://www.slideshare.net/ahmedalrashedi39/the-veneer-step-by-

step?next_slideshow=1

http://www.realself.com/question/comparison-dental-veneer-brands

http://www.animated-

teeth.com/porcelain_veneers/t3_porcelain_veneers_how.htm

http://www.jcda.ca/article/b143

Scientific papers:

Porcelain veneers: Treatment guidelines for optimal aesthetic by dr

Christopher Ho , Mr Brad Gobler.

A Review on Ceramic Laminate Veneers By Mathew, Sebeena Mathew,Karthik

KS .

PORCELAIN VENEERS: TECHNIQUES AND PRECAUTIONS BY BAZIL MIZRAHI.

Do’s and Don’ts of Porcelain Laminate Veneers by Chad.J.Anderson.Gerard

Kugel

No-Preparation Porcelain Veneers by Afnan El Zain.

Porcelain veneers – preparation design: A retrospective review.

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