Porcelain laminate veneers restorations


FIGURE 7-1 A, The patient presented with a midline diastema. She also thought her teeth were too long. B, The wax is refined with a plastic instrument. C, The diastema is closed with white orthodontic tray wax. D, Mars black acrylic paint is applied to the teeth with the wooden end of a cotton-tipped applicator. E, The black acrylic paint helps the patient envision the esthetic effect of shortening the teeth. F, A diagnostic wax-up simulating the proposed final porcelain laminate veneer restorations. G, A trayless polyvinylsiloxane (PVS) laboratory putty impression of the diagnostic wax-up to be used as a matrix when fabricating a polyurethane intraoral mock-up of the proposed restoration. H, The buccal areas of the matrix are trimmed with the Bard-Parker knife.   I, The appropriate amount of material is placed into matrix. J, The matrix filled with the polyurethane acrylic is seated intraorally. K, The intraoral mock-up of the proposed definitive restorations. Note how some areas of tooth structure remain uncovered by the polyurethane indicating that the definitive restorations will reproduce the shape of the original tooth structure in those specific areas.

Porcelain use decreased following the introduction of silicate cements in 1908. Although silicates, a combination of silica alumina and calcium fluoride, showed significant solubility in salivary fluids, the fluoride component provided anticariogenicity. Acrylic resins, introduced in 1946, immediately replaced silicate resins as the esthetic material of choice. Although they exhibited better long-term retention, they did not contain fluoride, which resulted in an increased incidence of recurrent decay. Advances in acrylic resin systems, compared with earlier restorations, controlled some of the polymerization shrinkage, but they still exhibited poor overall dimensional stability. In addition, like silicates, acrylic resins required mechanical retention. The introduction of the acid-etch technique and filled composite resins further diminished the use of porcelain as an internal restorative material. Porcelain, in the form of all-porcelain and porcelain-fused-to-metal restorations, was relegated to full coverage restorations.

In the late 1970s, direct and indirect laminate veneers were introduced. Direct veneers, which used light-cured composite resin to overlay the entire facial surface, allowed great flexibility in both shaping and shading teeth. However, they were time consuming and required substantial artistic skill. In addition, they exhibited poor color stability and wear resistance.

Indirect or preformed veneers attempted to overcome some of these limitations.3 Composed of acrylic, they were treated with ethyl acetate, methylene chloride, or methyl methacrylate and then luted to the etched tooth with a composite resin. Although they exhibited greater color stability and stain resistance than early direct composite resin veneers, the composite resin-to-laminate veneer bond proved to be a fatal weak link.4 The acrylic veneer also exhibited a dull and monochromatic appearance, poor abrasion resistance,5 and resulted in unsatisfactory gingival inflammation.

Porcelain-bonded restorations

Early research6 indicated that it was possible to chemically bond silica to acrylic or bis-GMA using a silane coupling agent. Most research79 focused on the direct chemical bonding of porcelain teeth to acrylic denture bases. Early silane bonds prevented seepage of oral fluids between the porcelain-acrylic interface.10 However, differences in the coefficient of thermal expansion between porcelain and acrylic caused bond deterioration during bench cooling of the heat-cured acrylic.

The need for a technique to repair ceramometal restorations with debonded porcelain prompted interest in the composite resin to porcelain bond. It was discovered that no bond formed between the glazed porcelain and composite resin, even with silane,101112 unless the surface was roughened.13

In 1983, the porcelain-laminate veneer was introduced.14 It combined the esthetic and positive tissue response of porcelain with the adhesive strength of acid-etch retained restorations and the convenience of a laboratory-fabricated restoration.

Basic chemistry

The porcelain-bonded restoration consists of four components

1. An internally etched porcelain veneer

2. A suitable tooth surface

3. A silane-coupling agent

4. A composite resin luting cement


Dental porcelains are composed of natural feldspar (both potassium and sodium aluminosilicate glasses).15 Early porcelain-laminate veneers used the same porcelains used in all-porcelain restorations. Later, high-strength porcelains specifically designed for bonded restorations were introduced. These materials are stronger than conventional porcelains and composite resin.

Acid etching

Retention of the acid-etch retained porcelain restoration is accomplished by the creation of microporosities in both the porcelain and enamel. Porcelain porosities are derived from treating the internal surface of the restoration with a 10% acid solution, such as hydrofluoric acid. Studies show that etching with or without the use of a silane coupling agent greatly increases bond shear strength, which can even surpass resin-enamel bond strength (Table 7-1).1617

Table 7-1

​Effects of Etching and Silane on Bond Shear Strength

Group Etch Silane Bond Shear Strength
A Yes No 2907 ± SD 165
B Yes Yes 3485 ± SD 340
C No No 564 ± SD140
D No Yes 978 ± SD390


Data from Hsu CS, Stangel I, Nathanson D. Shear bond strength of resin to etched porcelain [abstract 1095]. In Abstracts of papers: 63rd general session, International Association for Dental Research/Annual session, American Association for Dental Research, Las Vegas (1985) J Dent Res 64: 162-379, 1985.

Salivary contamination of the etched porcelain can significantly reduce bond strength. Application of 37% phosphoric acid for 15 seconds has been shown to restore the etched surface.18

Silane coupling agents

The function of a coupling agent is to alter the surface of a solid to facilitate either a chemical or physical process.10 Numerous silane coupling agents exist and are used in dentistry to increase the shear strength of the porcelain-to-composite resin bond.

These agents are believed to be capable of chemically bonding to silica in both the porcelain laminate veneer and the composite resin matrix. Scanning electron micrographs reveal that silane and etching eliminate the polymerization contraction gap, which forms in both etched, nonsilanated and unetched, silanated restorations by allowing the resin to better wet the surface.17 An in vitro study using two different types of feldspathic porcelain concluded that silane combined with the action of hydrofluoric acid gel is the most effective surface treatment for ceramics.19

Composite resin luting cements

Initially, laminate veneers were retained with auto-curing composite resins. Light-activated composite resin luting cements provided increased working time. Numerous viscosities are available. Different shades and opacities allow for color modification of the restoration.

Light-activated resins are ideally suited for most laminate veneers. However, they require sufficient light from a curing light to initiate curing. Therefore they should not be used when the light must travel through a thickness of porcelain that exceeds the manufacturer’s recommendations. Factors affecting this maximum depth include the specific light source, the age of the bulb, the shade and opacity of the laminate, and the shade and opacity of the composite resin cement.

Basic laboratory technique

Porcelain-laminate veneers can be fabricated by the laboratory in one of four ways: platinum foil backing, refractory casts, direct castings, or CAD-CAM machining.

Platinum foil backing. 

​This method can also be used to construct the all-porcelain crown. A very thin layer of platinum foil is placed on the die. The porcelain is layered on the foil. Then the porcelain-foil combination is removed from the die and fired in an oven. Before try-in, the foil is removed and the porcelain is etched.20

The use of platinum foil permits the porcelain to be repeatedly removed from and replaced onto the die during restoration fabrication. This permits easier access to the proximal margins. In addition, the thickness of foil creates a space for opaques and tinting agents.

Refractory casts. 

​The use of refractory casts is the most commonly used method of porcelain laminate veneer fabrication.21

The restoration is fired directly on a refractory die. This eliminates the platinum layer but makes repeated firings difficult once the laminate veneer has been removed from the die unless a duplicate refractory die is fabricated.

The advantages of the refractory cast include tighter contacts and the absence of the gap created by the use of platinum foil. The disadvantages are less room for coloring agents and more difficulty in adjusting proximal areas by the technician.

Direct castings. 

​Cast ceramic restorations are fabricated using the “lost wax” technique. This eliminates the need for multiple firings but requires extrinsic staining for coloration (see Chapter XX).


Use a platinum layer to make repeated firings easier after the laminate veneer has been removed from the die.

CAD/CAM machining. 

​Ceramic restorations can be manufactured either in the dental office or in the laboratory. A cast or video image of the preparation is required, and the restoration always requires modification of the surface porcelain to obtain proper color esthetics. (For a complete discussion, see the section on CAD/CAM systems in Chapter 23.)

Advantages of bonded porcelain restorations

The main advantages of bonded porcelain restorations are the following:

1. Excellent esthetics. Porcelain offers unsurpassed esthetics. Unlike direct laminate veneers, the porcelain laminate veneers depend less on the esthetic skill of the clinician.

2. Excellent long-term durability. Porcelain is both abrasion resistant and color stable. In addition, porcelain has excellent resistance to fluid absorption.

3. Inherent porcelain strength. Porcelain exhibits excellent compressive, tensile, and shear strengths when properly bonded to tooth structure.

4. Marginal integrity. Porcelain restorations bonded to enamel exhibit exceptional marginal integrity.

5. Soft tissue compatibility. Properly polished porcelain is highly biocompatible with gingival tissue.

6. Minimal tooth reduction. Anterior porcelain laminate veneers are considerably more conserving of tooth structure than porcelain-fused-to-metal and all-porcelain full coverage restorations.

Disadvantages of bonded porcelain restorations

The primary disadvantages of bonded porcelain restorations are the following:

1. Time. Multiple visits are required.

2. Cost. Laboratory involvement and additional chair time are required when compared with direct restorations, resulting in higher costs to the patient and clinician.

3. Fragility. Although strong when bonded to the tooth, bonded porcelain restorations are extremely fragile during the try-in and cementation stages.

4. Lack of repairability. Porcelain restorations are difficult, if not impossible, to repair.

5. Difficulty in color matching. Although porcelain restorations are color-stable, precise matching of a desired shade tab or an adjacent tooth can be difficult. In addition, shade alteration is impossible after cementation.

6. Irreversibility. Tooth reduction, although often minimal, is required.

7. Inability to trial cement the restoration. Unlike traditional indirect restorations, bonded porcelain restorations cannot be temporarily retained with a provisional cement for evaluation purposes.


Porcelain laminate veneers may be indicated in areas traditionally restored with single crowns or composite resin veneers for the following:

1. Correcting diastemata

2. Masking discolored or stained teeth

3. Masking enamel defects

4. Correcting malaligned or malformed teeth


Porcelain laminate veneers may be contraindicated for the following:

1. Patients who exhibit tooth wear as a result of bruxism

2. Short teeth

3. Teeth with insufficient or inadequate enamel for sufficient retention (e.g., severe abrasion)

4. Existing large restorations or endodontically treated teeth with little remaining tooth structure

5. Patients with oral habits causing excessive stress on the restoration (e.g., nail biting, pencil biting)

Diagnostic and treatment planning AIDS

Porcelain laminate veneers can be used to change any or all of the following characteristics of a single tooth or multiple teeth:

1. Color (including characterizations and degree of polychromaticity)

2. Size

3. Shape

4. Position within the arch

Wax and paint simulation

White orthodontic wax and acrylic paint provide an extremely effective diagnostic and patient education aid. This is especially helpful when evaluating the treatment of single or multiple diastemas, and fractured, misshaped, or malpositioned teeth. The wax can be used to quickly and inexpensively simulate (and thereby “preview”) the effects of porcelain laminate veneer placement.


Prediction of the anticipated outcome of porcelain laminate veneer placement without the use of a preliminary wax simulation is deceptively difficult even for the experienced dentist. A wax “preview,” often reveals a favorable prognosis for a clinical situation that initially appears unmanageable with porcelain laminate veneers.


White orthodontic tray wax (Hygienic Corp.)

Mars Black artist’s acrylic paint (Liquidtex Artist Materials)

Plastic instrument (Plastic Instrument PF4, Henry Schein, Inc.)

One-piece lip retractor (e.g., Self-Span, Ellman International, Inc. or Expandex, Parkell, Inc.)

Cotton-tipped applicator

Clinical technique 

1. Isolate the teeth with a one-piece lip retractor (Fig. 7-1 A).

2. Dry thoroughly with an air syringe.


Squeeze a 1⁄8-inch strip of orthodontic wax between the thumb and index fingers. This will quickly form a thin “veneer-shaped” piece of wax.

3. Apply the wax to the teeth and grossly mold to shape with the index finger.

4. Refine the wax with the plastic instrument (Fig. 7-1 B, C).


Simulate shortening of the teeth by applying an appropriate amount of black artist’s acrylic paint to the dried tooth surface, using the wooden end of a cotton-tipped applicator (Fig. 7-1 D). Turn off the examination light and have the patient separate the teeth until they do not exhibit vertical overlap (Fig. 7-1 E). Squinting augments the illusion.

Computer imaging

Computer imaging provides a two-dimensional prediction similar to the three-dimensional preview provided by wax simulation and acrylic paint. This system has the added advantage of previewing the effects of color and characterization changes and providing a more lifelike prognostication. Computer imaging systems can also provide instant printouts of the predicted changes (see Chapter 22).

Diagnostic wax-up / polyurethane clinical mock-up


The additional cost of diagnostic wax-ups can often be offset by the time saved when fabricating provisional restorations.


To simulate shortening of the teeth apply an appropriate amount of black artist’s acrylic paint to the dried tooth surface (see Clinical Tip in the section on Wax and Paint Simulation).


Diagnostic wax-up

Polyvinylsiloxane (PVS) laboratory putty (Lab-Putty Hard Silicone Putty, Coltène Whaledent, Inc.)

Bard Parker Knife with # 15 Scalpel Blade

Polyurethane provisional restoration material (e.g., Luxatemp Ultra, DMG America)

Clinical technique 

1. The dental laboratory technician fabricates a diagnostic wax-up to simulating the proposed final porcelain laminate veneer restorations (Fig. 7-1 F).

2. Adjust the diagnostic wax-up if necessary until it is acceptable to the clinician and the patient.

3. Make a trayless PVS impression of the diagnostic wax-up using laboratory putty (Fig. 7-1 G). This will be used as a matrix when fabricating a polyurethane intraoral mock-up of the proposed restoration.


Care should be taken to produce an impression with a consistent 2 to 3 mm thickness. Finger pressure will be used when the matrix is placed intraorally. If the matrix is too thin, this finger pressure could result in an undesired indentation of an area of the polyurethane mock-up. A matrix that is excessively thick could be overly rigid and difficult to manipulate.

4. Scallop the buccal areas of the matrix with the Bard-Parker knife (Fig. 7-1 H).


The buccal “notches” will serve as escape vents for excess polyurethane provisional material. Care should be taken to place the periphery of the matrix as close to the predicted interproximal finishing line as possible (see Figure 7-1 J for placement).

5. Select the appropriate shade of polyurethane provisional restoration material and place an appropriate amount into the matrix (Fig. 7-1 I).


Care should be taken to put the appropriate amount of polyurethane provisional material in the area of the prepared teeth. The amount will vary depending upon whether the contour of the final restoration is to be thicker or thinner than the original tooth. The latter requires far less material than the former.

6. Seat the matrix intraorally and allow the polyurethane material to polymerize (Fig. 7-1 J). Remove the matrix.

7. Finish and polish the mock-up until it is acceptable to the clinician and the patient (Fig. 7-1 K).


Removal of excess material from the interproximal areas at this time will reduce the amount of excess material in the mock-up. A high-speed suction can be used to evacuate excess material; however, an appropriate trap should be installed within the suction head to prevent the accumulation of cured material.


To simulate shortening of the teeth, apply an appropriate amount of black artist’s acrylic paint to the dried tooth surface (see Clinical Tip in the section on Wax and Paint Simulation).

Patient education


One of the most effective patient education tools is a book or photograph album containing before and after images of representative cases. These educational materials can be purchased commercially or be produced by the dentist (see also Chapter 22).

Demonstration porcelain laminate veneers. 

​Sample porcelain laminate veneers fabricated to fit on prepared denture teeth or stone casts are valuable patient education aids. They effectively demonstrate the conservative nature of this technique and the lifelike appearance of the definitive restorations.

Tablet software. 

​Computer tablet demonstration software or computer demonstration software is another patient education modality (for example, DDS GP for the iPad, Kick Your Apps, [Fig. 7- 2 A] and Guru Patient Communication Suite for the PC, Reality Engineering LLC, Reno [Fig. 7-2 B]).

FIGURE 7-2 A, Screen shot from the DDS GP for the IPad. B, Screen shot from an animation from the Patient Communication Suite for the PC. Source: ( A, Courtesy Kick Your Apps, Inc., Poway, CA. B, Courtesy Reality Engineering, LLC, Reno, NV.)

Tooth preparation

The outline form of the porcelain laminate veneer tooth preparation depends largely on the degree of desired color alteration. This consideration particularly influences the location of the interproximal and gingival finish lines.

Static area of visibility versus dynamic area of visibility

The entire facial tooth surface, including the gingival area and the area immediately facial to the contact area with the adjacent tooth (the facial embrasure), is visible if the available light and the perspective of the viewer are optimal. This static area of visibility occurs when the patient is seated in the dental chair under adequate lighting and with the lips fully retracted. The static area of visibility significantly differs from the actual dynamic area of visibility exhibited during normal function.

The dynamic area of visibility of the facial embrasure is partially a function of viewing perspective. It is particularly influenced, however, by shadows cast from surrounding structures. The lip, adjacent tooth contour and position, and gingival architecture, as well as the contour, shade, and position of the tooth under observation are all important factors (Fig. 7-3).

FIGURE 7-3​The dynamic area of visibility (the triangular area) of the facial embrasure is influenced by the depth of the embrasure space and by the shadow cast by surrounding structures including the tooth itself. A, The entire embrasure space is visible. The margins of the laminate veneers illustrated in the figure will be visible. To hide this margin, the finishing line must be placed into the contact area. B, The embrasure space is only partially visible. The margins of the porcelain laminate veneers illustrated in the figure are just within the nonvisible area. C, The majority of the embrasure space is not visible. The margins of the porcelain laminate veneer illustrated in need not have been placed as deeply into the interproximal area.

The dynamic area of visibility of the gingival area is governed by the position of the lip during maximal smiling (the high smile line).

Minimal or no color change

Proximal finishing lines. 

A proximal chamfer finishing line is preferred except when diastemata are present. Proximal areas adjacent to diastemata should receive a feather-edged finishing line (Fig. 7-4).

FIGURE 7-4​Feather-edged proximal finishing lines are used in proximal areas adjacent to diastemata.

Proximal contact area. 

​When the shade difference between the tooth (after preparation) and the desired definitive restoration is minimal, proximal chamfer finish lines are placed slightly facial (approximately 0.2 mm) to the contact areas of the adjacent tooth. This provides for the following:

1. Ease in evaluating marginal fit during the try-in stage

2. Access for performing and evaluating finishing procedures

3. Access for home care (margins in “self-cleansing” area)

4. Ease in evaluating marginal integrity during follow-up maintenance visits

The major disadvantage of this design is the possibility of eventual staining at the tooth-restoration interface. However, the factors influencing the dynamic area of visibility often negate this disadvantage. (See the section on static versus dynamic area of visibility in this chapter.)

Proximal subcontact area. 

​The proximal subcontact area (PSCA) consists of the interproximal tooth structure, which is immediately gingival to the contact area with the adjacent tooth. This area is usually not visible from a direct frontal view of the tooth (Fig. 7-5 A) and is therefore often left underprepared or totally unprepared. It is visible, however, from an oblique view. Therefore preparation of the PSCA is essential22 and is particularly crucial when the definitive restoration significantly differs in shade from that of the unprepared tooth structure and to avoid esthetic display of the restoration margins, which may eventually stain (see Fig. 7-5).

FIGURE 7-5 A, The proximal subcontact area is visible only from an oblique perspective and is often left unprepared or underprepared. B, Proper extension of the preparation into the proximal subcontact area. The proximal subcontact area is often overlooked during tooth preparation.


View the preparation of the PSCA from all oblique angles to ensure adequate extension into this often-overlooked area.


​The proximal area adjacent to a diastema should receive a feather-edged finishing line (see Fig. 7-4). This finishing line extends from the incisal edge to a point adjacent to the height of the gingival papilla.

Gingival finishing lines. 

​A chamfer is preferred for all gingival finishing lines. Supragingival finishing lines provide the same advantages as proximal finishing lines, which terminate facial to the contact areas. In addition, impressions are easier to make with supragingival preparations as compared with subgingival preparations. Supragingival finishing lines also increase the likelihood that restoration margins will end on enamel. The major disadvantage, however, is that any subsequent staining or color changes at the restoration margin will be visible. Therefore supragingival margins are limited to clinical situations in which this area remains concealed by the lip during maximum smiling (high smile line).

When the entire clinical crown is included in the facial display, the gingival margin should be placed 0.1 mm below the free gingival margin. If gingival recession is anticipated, the gingival finishing line can be extended deeper subgingivally as long as the biologic width is not violated.


Evaluate critically the true position of the lip during maximum smiling (the high smile line) before planning supragingival finishing lines. The true lip position may be deceptive. Patients with unattractive smiles often habitually adapt a high smile line position, which is significantly less revealing of tooth structure than is anatomically possible. After porcelain laminate veneers are placed, the high smile line may significantly elevate, because the patient’s psychologic barriers to full smiling have dissipated.

Incisal preparation. 

​Incisal reduction should ideally provide for 1 mm of porcelain thickness. Therefore if the incisogingival height of the definitive restoration is to be 0.5 mm longer than the existing tooth, only 0.5 mm of incisal reduction is required. If the preoperative teeth are to be lengthened by 1 mm, only a rounding of the incisal edge and placement of a finishing line are required.

A butt joint finishing line provides for the proper thickness of porcelain at the margin to prevent restoration fracture. The finishing line should slope slightly gingivally (approximately 75 degrees from the facial). This augments resistance to facial displacement of the definitive restoration (Fig. 7-6).

FIGURE 7-6​A butt incisal finishing line should slope approximately 75 degrees gingivally from the facial to provide resistance to restoration displacement and to provide for adequate thickness of porcelain at the margin to prevent restoration fracture.

After ideal preparation, the incisal outline of the tooth, when viewed from the facial aspect, should be identical to the incisal outline of the proposed definitive restoration, except for a 1-mm incisal reduction. This allows for an even thickness of porcelain. Incisal line angles must be rounded to reduce internal restoration stresses.

Facial depth reduction. 

​A facial reduction of approximately 0.5 to 0.7 mm is sufficient for most maxillary teeth and 0.3 mm for smaller teeth, such as mandibular incisors, if adequate thickness of enamel is present. Inadequate thickness of enamel, such as in the gingival one third of the tooth, may require a more conservative tooth reduction. Teeth or portions of rotated tooth surfaces that are in lingual version require proportionately less reduction. Preparation into dentin is sometimes necessary; however, this should involve less than 50% retention of the prepared surface.16

The entire finishing line should ideally remain in enamel.

Major color change

In addition to considerations of preparation design for minimal color changes, major color differences between the prepared tooth and the desired definitive restoration may also require other adjustments. Visibility of the contact area may necessitate extension of the interproximal finishing line into the contact area to a depth of approximately one-half the labiolingual dimension of the contact area. (See the sections on minimal or no color change and static versus dynamic area of visibility in this chapter.) The gingival finishing line can be extended 1 mm subgingivally, assuming the biologic width is not violated. Supragingival margins are indicated, however, if this area remains concealed by the lip during maximal smiling (high smile line). (See Clinical Tip in the section on gingival finishing lines.) The preparation depth may be increased if sufficient thickness of enamel is present. This will allow for an increased thickness of porcelain.


Tetracycline discoloration occurs in the dentin. The prepared tooth may be darker than the original tooth shade, because the deep tooth preparation that is often necessary in these situations removes a significant amount of the “masking” enamel.


Basic dental setup


High-speed handpiece

Low-speed handpiece

Mouth mirror

Periodontal probe

Suitable anesthesia (if necessary)

Lip retractor (e.g., One-piece Self-Span, Ellman International, Inc. Manufacturing Co.; Expandex, Parkell, Inc. or Lip Expanders, Denmat, Inc.)

High-speed (friction grip) diamond three-tiered depth cutting burs (e.g., LVS-1 [0.3 mm depth cut] and LVS-2 [0.5 mm depth cut], Brasseler USA)

High-speed (friction grip) two-grit burs (LVS-3, LVS-4, Brasseler USA)

High-speed (friction grip) diamond wheel bur (e.g., 5909, Brasseler USA

Unwaxed regular dental floss

Sharp pencil

Retraction cord packer (e.g., Fischer’s Ultrapak Packer, Ultradent Products, Inc.)

Nonimpregnated gingival retraction cord (e.g., Ultrapak No. 0 or No. 1, Ultradent Products, Inc.; Gingibraid No. 0 or No. 1, Van R Dental Products, Inc.)

Gingival retraction instrument (e.g., Zekrya Gingival Protector, DMG America, Inc.) (optional)

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May 29, 2015 | Posted by in Esthetic Dentristry | Comments Off on Porcelain laminate veneers restorations

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