Veneer Cementation Protocol: From Try-in to Cleanup

Veneer cementation is the step where months of planning can be lost in a few minutes: a drop of saliva, an unnoticed silicone residue or a cement film left in the sulcus is enough to compromise a 0.5 mm ceramic shell. This article sets out the protocol Dr Jan Hajtó uses and teaches, built on four requirements that every adhesive bond has to meet, and checks each step against the manufacturers' instructions for use. You will know what to do from try-in to final polish and which mistakes are worth avoiding.

Four requirements behind every veneer cementation

Dr Hajtó reduces adhesive cementation to four conditions. Each step in the protocol below serves one of them:

1. A saliva-free, dry and accessible working field.
2. Complete polymerisation of the adhesive and the luting material.
3. High wettability of both surfaces to be joined: clean, micro-retentive, free of oils, silicone and residue.
4. Residue-free removal of excess luting material.

How much these details matter is shown by a two-centre clinical trial of bonded glass-ceramic inlays: with the same materials, the 4-year survival rate was 97.4 % for one operator and 75.4 % for the other, and the authors concluded that the operator influence on clinical outcome was clearly proven (Frankenberger et al. 2009). The protocol is only as reliable as its weakest step.

Cementation also starts long before the appointment. A preparation kept in enamel, guided by the diagnostic wax-up and mock-up, gives the best bonding substrate; the preparation sequence is described in veneer prep step by step. Exposed dentin should be sealed immediately after preparation: in a microtensile study, immediate dentin sealing reached 58.25 MPa, delayed sealing after the provisional phase only 11.58 MPa (Magne et al. 2005). Lithium disilicate veneers must be bonded adhesively; Ivoclar lists adhesive cementation as mandatory for IPS e.max Press veneers (IPS e.max Press IFU, Rev. 2, 2026). For material selection see E.max vs zirconia.

Try-in: fit, contacts and shade

Removing the temporaries

Remove the provisionals and clean the preparation completely. Ivoclar recommends a polishing brush with an oil- and fluoride-free paste and warns that cleaning with alcohol can dehydrate dentin (Variolink Esthetic LC IFU, Rev. 1, 2025). How residues of temporary cement affect the bond and how to remove them is covered in veneer temporaries.

Fit and contacts

Try in each veneer individually for marginal fit, then all together for the proximal contacts. Take care when checking occlusion before cementation: unbonded thin ceramic can fracture under load, which is why Ivoclar explicitly warns about this step.

Never use silicone fit checkers on bonding surfaces. Silicone has an extremely low surface energy, and neither alcohol nor acid removes it reliably. On zirconia contaminated with saliva and a silicone disclosing medium, Quaas and colleagues found that air abrasion gave significantly higher bond strengths than all other cleaning methods, while alcohol cleaning did not provide durable bond strengths (Quaas et al. 2007). The Ivoclean instructions list cleaning of restorations that have been in contact with silicone-based pastes as a contraindication (Ivoclean IFU, Rev. 0, 2025).

Shade: what the try-in paste does and does not show

Try-in pastes simulate the luting composite, but not perfectly. In Dr Hajtó's experience, veneers always look slightly greyer and more translucent after bonding than they did with the try-in gel. The literature points the same way: Xu and colleagues found that the colour of try-in pastes and the corresponding luting composites did not always match at veneer thicknesses of 0.7 and 0.5 mm (Xu et al. 2014). At the same time, the shade of the luting composite has only a small effect overall: with IPS Empress from 0.5 to 3 mm thick, two cement shades produced no perceivable difference in final colour (Terzioğlu et al. 2009). Dr Hajtó's conclusion: with a precise fit, the luting shade is not a significant factor.

Preparing the ceramic

Hydrofluoric acid etching

Glass ceramics are etched with hydrofluoric acid, which dissolves the glass phase and creates a micro-retentive surface. Dr Hajtó prefers to have the veneers etched in the laboratory: the matt etched surface is easy to check against the glazed outer surface, and the etch must reach all the way to the margins. For 5 % hydrofluoric acid, Ivoclar specifies:

Source: Variolink Esthetic LC IFU, sections 2.3.2. Hydrofluoric acid is highly toxic, is used extraorally only, and requires protective glasses and gloves.

Cleaning after try-in

Saliva and sulcus fluid contaminate the etched surface during try-in. For restorations etched in the laboratory, Ivoclar's sequence is: rinse, dry, cover the bonding surface with Ivoclean, leave it for 20 s, rinse thoroughly, dry with oil-free air, then prime (Ivoclean IFU). Any surface that was silanised before try-in must be primed again. If the veneers arrive unetched, etch them after try-in.

Silane: separate primer or silane-containing adhesive?

The classic step is a silane primer, for example Monobond Plus, left for 60 s and then dispersed with a strong stream of air (Variolink Esthetic LC IFU, 2.3.2.2). Silane reacts with water, so the ceramic must be completely dry.

Dr Hajtó's current protocol uses a silane-containing universal adhesive, Scotchbond Universal Plus, as silane and adhesive in one step on the ceramic. For use as a primer on the restoration, 3M refers to the same application steps as on the tooth (rub in for 20 s, then air for at least 5 s until the film is shiny and no longer moves) and states that the adhesive is not light-cured on the restoration (Scotchbond Universal Plus IFU). The evidence depends on the product:

• With Scotchbond Universal Plus on HF-etched lithium disilicate, a prior silane did not increase bond strength (43.3 MPa without vs 31.3 MPa with prior silane after 24 h; 33.6 vs 30.3 MPa after six months) (da Silva et al. 2024).
• With the earlier Scotchbond Universal, additional silanisation of HF-etched lithium disilicate significantly improved tensile bond strength (Maier et al. 2019).

The practical rule: check whether your universal adhesive actually contains silane. If it does not, a separate silane step is required.

A self-etching ceramic primer (Monobond Etch & Prime: scrub 20 s, react another 40 s) avoids hydrofluoric acid at the chair. Results vary: Maier and colleagues found no significant difference from HF plus silane, whereas Lopes and colleagues measured significantly lower bond strengths than with every HF gel tested (Lopes et al. 2019). In Dr Hajtó's protocol, glass-ceramic veneers are etched with hydrofluoric acid.

Isolation without compromise

A rubber dam is useful but, in Dr Hajtó's view, not a precondition for veneers. What matters is that the field stays dry. His relative isolation consists of:

• PTFE tape around the neighbouring teeth, protecting them from etchant, adhesive and composite,
• a PTFE cord (0.6 or 1.0 mm) in the sulcus, which does not fray, does not soak up fluid and does not bond to adhesives (see gingival retraction cord),
• a small palatal suction tip and an attentive assistant,
• no compromise: if the field is contaminated, clean and condition again.

Avoid astringent haemostatic agents on surfaces you are about to bond. A systematic review of 20 in vitro studies found that 10 of the 12 studies on contaminated dentin reported a significant decrease in bond strength, with self-etch adhesives more affected than etch-and-rinse systems (Bernades et al. 2014). 3M also advises against desensitisers, disinfectants, astringents and hydrogen peroxide before applying Scotchbond Universal Plus, with the exception of chlorhexidine solutions.

Conditioning the tooth

1. Clean the preparation completely; place a cord if needed and protect the neighbours with PTFE tape.
2. Etch the enamel with phosphoric acid. Dr Hajtó etches for 15 to 20 s; 3M specifies 15 s for selective enamel etching with Scotchbond Universal Plus, and Ivoclar 15 to 30 s with Total Etch in its Variolink Esthetic LC instructions.
3. Rinse thoroughly, for at least 10 s in Dr Hajtó's protocol, and dry carefully until the enamel appears chalky white.
4. Rub in the adhesive for 20 s, then direct a gentle stream of air over it for at least 5 s until a shiny film no longer moves. A dull film is too thin and must be re-applied. Work with a yellow filter on the headlamp so the adhesive does not cure prematurely.
5. Light-cure the adhesive on the tooth as its instructions require. For Scotchbond Universal Plus, 3M requires 10 s of light curing for all resin cements other than RelyX Universal and for all direct composites; this step comes from the manufacturer's instructions, not from a separate rule of Dr Hajtó's.

Seating, excess removal and final curing

Dr Hajtó uses a filled, purely light-curing flowable restorative composite (G-ænial Universal Injectable in shades BW, JE or A2) instead of a dedicated luting cement. This is his own clinical choice: GC does not list luting among the indications of G-ænial Universal Injectable, so its use as a luting material is off-label and at the clinician's own responsibility. If you prefer to stay within the indications, use a light-curing luting composite indicated for veneers, such as Variolink Esthetic LC. Purely light-curing materials leave time for seating and excess removal, provided intense light is kept away. Gresnigt and colleagues bonded lithium disilicate veneers to 40 central incisors with either a light-curing luting cement or a restorative composite; after thermomechanical ageing, the composite group withstood higher loads in the fatigue test (mean 1165 N vs 762.5 N) (Gresnigt et al. 2017). This is a laboratory study, and higher viscosity demands a precise fit.

1. Apply the composite to the inner surface of the veneer so that it is completely wetted, and a small amount cervically on the tooth.
2. Seat the veneer with gentle pressure, remove gross excess and check the seat.
3. Tack-cure briefly. For Variolink Esthetic LC, Ivoclar describes 2 s at 10-15 mm distance, moving the light in a circle along the veneer margin.
4. Remove excess while it is still gel-like: interproximally with floss and fine scalers, at the margin with a back-bent scalpel blade (Fig. 12). A wedge helps to block the interdental space.
5. Remove the cord and the PTFE tape.
6. Cover the margins with glycerine gel to prevent an oxygen-inhibited surface layer; for Variolink Esthetic LC, Ivoclar gives its thickness as about 50 µm (Variolink Esthetic LC IFU, 2.6).
7. Cure completely: Dr Hajtó cures for at least 2 minutes per tooth, with the light tip in full contact and aimed precisely; two lamps halve the time. Cool the tooth with an air or water spray to avoid heat build-up.
8. Finish the palatal margin with a fine white stone, the interproximal margins with an oscillating file and polishing discs, then check occlusion and excursions.

For comparison, Ivoclar's curing time for Variolink Esthetic LC is 20 s per millimetre of ceramic and segment at 500-800 mW/cm², or 10 s at 900-1,300 mW/cm².

Common mistakes in veneer cementation

Summary

A reliable veneer cementation protocol follows four requirements: a dry field, complete curing, clean and wettable surfaces, and residue-free excess removal. In practice that means etched ceramic cleaned with Ivoclean after try-in, a silane-containing adhesive or a separate silane, phosphoric acid on enamel, relative isolation with PTFE tape and cord, a light-curing filled composite, careful removal of excess and generous light curing. You can practise the full sequence on patients in Dr Hajtó's hands-on veneer courses for dentists.

Frequently asked questions