porcelain laminate veneers: concepts and techniques | col douglas p. rockwood

Porcelain Laminate Veneers:Concepts and Techniques

Col Douglas P. Rockwood AEGD-2 Program

Wilford Hall Medical Center

Overview: Porcelain Laminate Veneers• History • Materials • Advantages/Indications • Disadvantages/Contraindications • Porcelain veneer technique • Laboratory communication • Durability data, other current literature • Summary

Porcelain Veneers: History• 1903: Land

– First recorded all-porcelain restoration (PJC)

• 1930s: Pincus – Hollywood movie actors – Thin facings of air-fired porcelain – Affixed with denture powder – Very weak, non-functional

Porcelain Veneers: History• 1955: Buonocore: Acid etching of enamel • 1975: Rochette: Tooth repair with etched porcelain blocks • 1983: Horn: Porcelain laminates with acid-etching • 1983: Simonsen: Use of silane, high bond strengths • 1985-Present:

– Continued development of porcelain and resin luting systems

– Improved dentin-bonding systems – Long-term clinical trials successful

Types of Veneers• Porcelain

– Numerous systems; conventional feldspathic porcelain

• Cast, Pressed or Machined Ceramics – Dicor – IPS Empress, Optec – Cerec, Celay

• Light, vacuum or heat processed resins

Types of Veneers• Conventional low-fusing feldspathic porcelain

– Most commonly used material for veneers – Readily etched and silanated – Micro-cracks possible, careful handling required – Two methods of fabrication

» Platinum foil technique » Refractory material

• Most common method

Types of Veneers• Other Ceramics

– Many systems are variants of feldspathic porcelains – Ceramic is a general term

» from “keramos” (Gr.): meaning “burnt stuff” – Additives or changes to conventional porcelains to achieve

enhanced physical properties, ease of manipulation or esthetics – Problems:

» Wear of opposing teeth

» Shorter clinical track record » Potentially brittle with subsequent catastrophic failure

Varying Opacity Between Porcelains

Porcelain Veneers: Advantages• Extremely esthetic

– Color stability, translucency, texture, vitality

• Bond strength • Durability • Biocompatibility: superior tissue response • Gingival esthetics • Conservative compared to full coverage • Coefficient of thermal expansion

Contact Lens Effect• Reduces visibility of porcelain margin • Minimizes need for subgingival margins • Results in sustained esthetics even in cases of apical

migration of attachment • Less effective with highly opaque porcelains or

luting resins

Contact Lens Effect

Remember to record the shade of the porcelain and the shade (and type) of cement used...

Porcelain Veneers: Indications• Mild to moderate discoloration • Diastema closure • Rotations/slight malposition • Enamel malformations/pitting • Tooth augmentation (e.g. peg lateral) • Replacement of inadequate resin composite veneers

Porcelain Veneers: Disadvantages• Preparation required, irreversible/invasive procedure • Limited ability to mask staining • Technique sensitive • Fragility prior to cementation • Lab fees/interaction, multiple appointments, expense • Resin margins, usual site of eventual breakdown

Marginal Breakdown

Microcracks: Do not cement!

Porcelain Veneers: Contraindications• Extremely dark tooth discoloration • Lack of enamel for bonding • Deciduous teeth • Severe bruxism/anterior wear • Patient desires reversible procedure • Cost issues • Severe crowding • Heavily restored teeth/Caries active patient

Masking Moderate-Severe Staining:

• Pre-operative bleaching (has limits) • Heavier tooth preparation • Use of complementary colors to neutralize tooth

discolorations • Increase opacity of porcelain/ resin luting composite • Heavy superficial staining to “break up” restorations

Porcelain Veneer Technique• Preoperatively:

– Adequate examination, problem list and treatment plan – Photos – Diagnostic casts – Radiographs – Diagnostic wax-up – Treatment review with the patient

Porcelain Veneer Technique• Shade selection:

– Hydrated teeth – Natural light source – Evaluate underlying discoloration – Remember enamel contribution to color (minimal)

Tooth Preparation

To Prepare or Not?“Veneers can be done to a knife edge with an extremely skilled ceramist and gentle seating… but they will break frequently and may adversely effect color, contours, and the periodontium.”

-Garber, 1998

Tooth PreparationGeneral Comments

• Uniform facial reduction of approximately .5mm • Carry interproximals 1/2 to 2/3 into the contact • Lingual extension/Incisal prep design vary with

situation • Follow tooth contours in margin placement:

– Tuck in the cervical margin below the contact

Tooth Preparation• Remember varying enamel thickness

– .3 mm cervical – .6 mm mid-facial – 1.5 mm incisal

Incisal Preparation Designs

Feathered Incisal Edge Incisal Bevel

Incisal Overlap Incisal Notch

Preparation Designs• When to do which design?

– Tailor to the clinical situation – Remember the principles of treatment

» Maximization of esthetics » Conservation of tooth structure

Porcelain Veneer Technique• Preparation Appointment:

– Anesthesia » Advised for both preparation and delivery appointments


– Rough out preparation » Depth cuts with two-planes of orientation » Establish veneer outline form » Connect depth cuts/establish uniform surface » Examine for draw and adequacy of prep


– Once rough preparation complete, retraction with OO cord or 3.0 BSS to allow access to refine and smooth margins


– Final impression


– Provisional restorations?

Provisional Restorations• Often unnecessary • Required for:

SensitivityInterim esthetics

Incisal edge reduction

Provisional Restorations• Technique:

– Bulk placed, spot-etched, direct composites – Vacuum-formed stent can be used for multiple units

Be careful! This is a dangerous technique for provisional or final restorations

Laboratory Communication• Critical to success of case:

– Communicate clearly to the lab – Explain treatment goals:

» Diastema closure » Incisal extension » Masking discolorations

– Expressly address desired opacity of veneers – Send photos if possible – Diagnostic wax-up helpful

Porcelain Veneer Insertion• Before the appointment:

– Verify the fit of veneers on the master cast » Individually and in groups

– Be critical of contours and emergence profiles – Evaluate level of opacity/translucency

Porcelain Veneer Technique• Delivery Appointment:

– Anesthesia


– Retraction and removal of provisional veneer


– Pumice the preparations – Can perform trial etch if uncertain of resin removal


– Veneer try-in

Veneer Try-in• Individually to evaluate margins • In groups to evaluate contours and contacts • Dry • Wet to evaluate shade

– Glycerin – Water – Try-in pastes – Try in with actual cement


– Veneer cementation

Cementation• Etch teeth • Etch and silanate veneers, (a critical step!) • Prime/Bond teeth (do not cure!) • Prime/Bond veneer(s) if manufacturer recommends

(do not cure!) • Load cement in veneer(s), push to place • Unfilled resin brush to wipe away excess (or not!) • Cure extensively

Cementation Systems• Criteria:

– Viscosity, convenience, activation system, shade selection, cost

• Examples: – Nexus and Nexus 2 (Kerr) – Illusion (Bisco) – Enforce (Dentsply) – Opal Luting Composite (3M)

Porcelain Etchants• Generally 9.5-10.0% HF acid • Follow manufacturer’s recommendations • Contact times generally 3-5 minutes • Consider use of barrier gels • Rinse thoroughly

Silane Coupling Agents• Silane acts in several ways

– Improves etched veneer surface for resin adhesion » Better resin wetting » Provides a chemical link from porcelain to resin (Bonds

to both structures)

• Highest resin-porcelain bond strengths achieved with hydrofluoric acid etch and use of silanes

• Pre-activated silanes have limited shelf life • Inactive silane is worse than no silane

Note difference between enamel and dentin etch

Insertion• Gentle but firm seating pressure • Apical and Lingual direction • Verify ahead of time that you can “hit the target” • Verify accurate seating before curing


– Finishing » Avoid rotary instrumentation if possible » Atraumatic technique » Verify that floss passes through contacts » Evaluate/refine occlusion

Finishing• #12 or #12B for gross excess • Hand instruments

– Chisels, hatchets • Sandpaper strips • Porcelain polishing points (Dialite®) • Micron diamonds

• Polishing pastes

Follow-up• Generally a one-week POT to check for residual

cement • Review hygiene and maintenance requirements • Photos

Maintenance• Avoid use of ultrasonic scalers, air abrasion units,

and other forms of abrasive • Avoid or control parafunctional activity • Night guard advisable Robbins, 1996

Porcelain Veneer Durability• “97% retained at 4 years”

– Jordan, 1989

• “100% retained at 5 years” – Mixson, 1995

• “93% success over 7-10 years’ – Strassler

• “>95% success at 8 years” – Garber, 1998

Veneer DurabilityPeumans et al, Journal of Dentistry 28 (2000) p. 163-77

– 13 separate clinical trials reviewed – Very low failure rates (0-5 %) – Periodontal response: acceptable to excellent – Excellent esthetics – Very high patient satisfaction

Factors in Long Term Success with Veneers

• Preparations confined to enamel only • Suitable luting agent, handled appropriately • Correct surface preparation • Closely adapted margins • No preparation design identified as superior

Peumans, 2000

Veneer Failures:• Porcelain fracture (early) • De-bonding at cement/silane junction (early) • Esthetic failures (early) • Leakage/staining at margins (late) • Caries (late)

Clinical Cases

Putting it Together:• Treatment planning is critical to success • Preparations required • Vary preparation design appropriately • Consider anesthetic at both appointments • Take control of the operative field • Use of hand instruments and #12 blades • Minimize use of opaque porcelains/cements • Adequate follow-up and maintenance

Acknowledgement

Dr David Garber Dr James Broome Dr David Murchison

Not to mention Col Grant R. Hartup!

Thanks... Any Questions?

porcelain laminate veneers: concepts and techniques | col douglas p. rockwood

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