Overlay goes digital

Endodontically treated teeth need cusp protection, most of the times, be it with partial or complete restorations.
In this case, the tooth was reconstructed using a fiber post, but luckily quality and quantity of residual enamel allowed us to restore this tooth with a lithium disilicate overlay to protect it towards masticatory loads. This case was performed using a digital workflow.

tooth after endodontic treatment

After the RCT a fiber post was cemented and a composite build up was done to seal the tooth. Residual enamel was thick and good, so we decided to only proceed to cusp coverage by fabricating an overlay.

color check for overlay fabrication

The shade for the indirect restoration was taken before preparing the cavity.

overlay cavity design on molar

The tooth was prepared to achieve complete cusp coverage as it wasn’t vital, and neighboring teeth were polished.

digital scan of overlay preparation

A digital scan was taken, here you can see a screenshot from the .stl file and details of the preparation without the high definition

stl impression file for overlay

CAD file before the project showing contact points

overlay on digital model

CAD design showing unchanged occlusion on the neighboring teeth, and the onlay project.

waxed overlay design

After CAM processing, check of the physical wax project.

lithium disilicate overlay on printed model

A pressed lithium disilicate overlay was fabricated and then colored and polished.

overlay preparation

Isolation with rubber dam before adhesive cementation.

try in on lithium disilicate overlay

Try in was carried out under rubber dam isolation to check proximal and marginal fit.

detail of marginal overlay adaptation

Marginal adaptation was checked on all sides.

etching of preparation

Enamel and composite build-up were etched using 37% orthophosphoric acid.

adhesive application with microbrush

A universal adhesive system (Scotchbond Universal, 3M) was used for bonding.

processing of overlay surface

The surface of the overlay was treated using hydrofluoric acid, polish and adhesive.

luting of overlay with composite excess

Heated composite (A3 Filtek Bulk One,3M) was used for cementation.

overlay after cementation with excess

After light curing and excess removal, before finishing.

comparison of occlusion between digital project and reality

Here you can see how similar the final outcome is in reality compared to the digital project.

cemented lithium disilicate overlay

At check-up, 10 days later. Integration is satisfactory.

lithium disilicate overlay on molar

At check-up, 10 days later.


Adhesive indirect restorations are an excellent solution to give stability and resistance to endodontically treated teeth while saving sound tissue.
Using the correct build-up technique it is possible to preserve healthy enamel. New technologies and materials allow dentists to work in an aesthetic and accurate way.
Thanks to DT Alessandro Arnone for the fundamental contribution.


1. Boeddinghaus M, Breloer ES, Rehmann P, Wöstmann B. Accuracy of singletooth restorations based on intraoral digital and conventional impressions in patients. Clin Oral Invest. 2015;19:2027–2034.
2. Seelbach P, Brueckel C, Wöstmann B. Accuracy of digital and conventional impression techniques and workflow. Clin Oral Invest. 2013;17:1759–1764.
3. D’Arcangelo C, Vanini L, Casinelli M, Frascaria M, De Angelis F, Vadini M, D’Amario M. Adhesive Cementation of Indirect Composite Inlays and Onlays: A Literature Review. Compend Contin Educ Dent. 2015;36(8):570-7.
4. Zarow M, Devoto W, Saracinelli M. Reconstruction of endodontically treated posterior teeth with or without post? Guidelines for the dental practitioner. Eur J Esthet Dent. 2009 Winter;4(4):312-27.


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