The step-luting technique optimizes the cementation of indirect

restorations using dual-cure resin cement, addressing a critical

phase in restorative procedures. A 5-second light cure stabilizes

the restoration while maintaining the cement in a gel-like state for easy

excess removal. After a 20-second wait, a final 40-second light cure ensures

complete polymerization, enhancing bond strength and marginal adaptation.

The self-curing component guarantees polymerization even in areas with

limited light exposure. This technique improves clinical efficiency, reduces

stress on the restoration, and ensures long-term stability.

The following clinical case demonstrates the step-by-step fabrication and

cementation of an overlay on an endodontically treated molar with a faulty

composite restoration.

Image

Image

Fig. 1 - Initial situation. The patient showed an old

unaesthetic composite reconstruction with several

cracks on lower first molar. With the compliance of the

patient, the treatment plan involved the replacement of

the existing composite restoration with an indirect one.

Image

Fig. 2 - Guide for occlusal reduction. A cross was

created to serve as a guide for occlusal reduction and

the subsequent preparation for an overlay, utilizing a

diamond cylindrical bur. It is preferable to initiate the

preparation in the central fossa, progressing along the

sulcus in order to achieve an even 2 mm of occlusal

reduction in the deepest part.secured with ligatures.

Image

Fig. 3 - Preparation steps. First reducing the occlusal

surface, followed by the interproximal areas.

Image

Fig. 4 - Finalized tooth preparation. Finalized tooth

preparation with a smooth, rounded surface, free of

interproximal boxes and sharp angles.

Clinical Case

Image

Fig. 5 - Conventional impression taking.

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Fig. 6 - Provisional placement. For the provisional

restoration, Telio material was applied to cover and

protect the preparation while awaiting the fabrication of

the definitive indirect restoration. It is essential to verify

stability and occlusion before dismissing the patient.

Image

Fig. 7 - Fabrication of the indirect restoration.

Image

Fig. 8 - Rubber dam placement. Following provisional

removal, the rubber dam was applied to initiate the

cementation of the indirect restoration.

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Fig. 9 - Air abrasion. The tooth was air-abraded to clean

the surface using AcquaCare (Velopex International)

with 50 μm aluminum oxide, following the Style Italiano

protocol.

Image

Fig. 10 - Etching. The indirect restoration was

conditioned according to protocol. First, 9%

hydrofluoric acid was applied for 20 seconds and

then rinsed off. In addition, to ensure a clean intaglio

surface and remove residues, additional etching was

performed with 37% phosphoric acid for one minute.

Silane was then applied with a brush and air-dried to

facilitate alcohol evaporation.

Image

Fig. 11 - Bonding. OptiBond Universal (Kerr) was applied

into two layers on both the onlay intaglio surface and the

tooth preparation with thorough rubbing and scrubbing.

This was followed by air-blowing for 20 seconds.

Image

Fig. 12 - Cementation. After that, NX3 Nexus Third

Generation (Kerr) luting cement was applied, and the

onlay was immediately set onto the tooth.

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Fig. 13 - Step curing technique. The ‘step curing’

technique allows for the controlled removal of excess

material while it is still soft, making it easier to clean up

the margins. Initially, the resin cement was light-cured for

about 5 seconds to slightly harden the material, allowing

the clinician to easily remove the soft excess around the

margins of the restoration using a fine instrument (LMFissura,

LM-Arte).

Image

Fig. 14 - Removal of the excess. Using the Eccesso

instrument from the LM-Arte kit and dental floss, it is

possible to easily remove excess cement before it fully

hardens. This approach ensures a safe and efficient

cleanup of the restoration margins.

Image

Fig. 15 - Final polymerization. After cleaning up the

excess material, a glycerine was applied to ensure a

complete degree of conversion of the resin cement

material. Thus, the final polymerization was completed

with an additional 40 seconds of light-curing.

Image

Fig. 16 - Polishing. The restoration-tooth interface was

carefully polished using a brown rubber polisher to

enhance both the aesthetic outcome and the properties

of the resin cement.

Image

Fig. 17 - Occlusal adjustment. Once the rubber dam was

removed, occlusal adjustments were carefully verified to

ensure proper stability and function.

Image

Fig. 18 - Radiographic examination. First lower molar

radiographic examination, before and after.

Conclusion

The successful outcome of this clinical case highlights

the importance of proper preparation design and precise

cementation protocols in ensuring the longevity and

functionality of the restoration. The step-luting technique,

combined with the use of a dual-cure resin cement,

allowed for controlled polymerization, optimizing bond

strength and marginal adaptation. Additionally, careful

occlusal adjustments and stability verification were

essential to achieving a predictable and durable result.

This approach simplifies the cementation phase,

minimizing stress on the restoration while enhancing

clinical efficiency.

Bibliography

1. Tosco V, Monterubbianesi R, Orilisi G, Sabbatini S, Conti C, Özcan M, Putignano A, Orsini G. Comparison of two curing protocols

during adhesive cementation: can the step luting technique supersede the traditional one? Odontology. 2021 Apr;109(2):433-

439. doi: 10.1007/s10266-020-00558-0. Epub 2020 Oct 31. PMID: 33128650; PMCID: PMC7954706.

2. da Veiga AMA, Cunha AC, Ferreira DMTP, da Silva Fidalgo TK, Chianca TK, Reis KR, et al. Longevity of direct and indirect resin

composite restorations in permanent posterior teeth: a systematic review and meta-analysis. J Dent. 2016;54:1–12.

3. Angeletaki F, Gkogkos A, Papazoglou E, Kloukos D. Direct versus indirect inlay/onlay composite restorations in posterior teeth.

A systematic review and meta-analysis. J Dent. 2016;53:12–21.

MKT-25-0236 Rev-0

Disclosure: Prof. Angelo Putignano is a consultant for Kerr. The opinions and technique expressed in this article are based on

the experience of Prof. Angelo Putignano. Kerr is a medical device manufacturer and does not dispense medical advice.

Clinicians should use their own professional judgment in treating their patients. All trademarks and brand names are the property

of their respective owners.