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Revista Portuguesa de Estomatologia,
Medicina Dentária e Cirurgia Maxilofacial

rev port estomatol med dent cir maxilofac. 2021;62(3):150-156

Original Research

Influence of cement type on the fracture resistance
of resin nanoceramic crowns over knife‑edge

margins: A pilot study

1,
1
1
Joana Guerreiro * , Rafael Dias , José Carracho
1 Faculdade de Medicina Dentária da Universidade de Lisboa, Lisboa, Portugal

a r t i c l e i n f o a b s t r a c t

Article history: Objective: To evaluate the influence of the type of cement on the fracture resistance of
Received 2 October 2020 full-contour resin nanoceramic crowns cemented over preparations with knife-edge margins.
Accepted 29 July 2021 Methods: A right lower premolar typodont model was prepared with a 1.5-mm axial reduction,
Available online 28 September 2021 a 2.0-mm occlusal reduction, and a knife-edge vertical margin. An anatomical crown was
designed from the digital scanning of the preparation using CAD/CAM software. Then, 20
Keywords: crowns were milled from resin nanoceramic CAD/CAM blocks (Cerasmart270™) as well as a
CAD/CAM blocks replica of the dental preparation in a cobalt-chrome alloy. The 20 crowns were randomly di-
Fracture resistance vided into two groups. Group 1 crowns were cemented with self-adhesive resin cement (G-CEM
Resin-modified glass ionomer LinkAce™) and group 2 crowns with resin-modified glass ionomer cement (FujiCEM™ 2).
cement Subsequently, they were subjected to a loading test on an Instron universal testing machine
Resin nanoceramic until fracture occurred. The data were statistically analyzed using the parametric Student’s
Self-adhesive resin cement t-test (α=0.05).
Results: The type of cement was shown to have a statistically significant effect on the
crowns’ fracture resistance (p <0.001). Group 1 presented a mean of 1284.3±340.19 Newtons,
much higher than the mean recorded in group 2, of 417.9±106.35 Newtons, with an increase
of 207.3% in the fracture resistance after self-adhesive luting.
Conclusions: Resin nanoceramic crowns cemented with self-adhesive resin cement showed
considerably higher fracture resistance than those cemented with resin-modified glass ion-
omer cement. (Rev Port Estomatol Med Dent Cir Maxilofac. 2021;62(3):150-156)
© 2021 Sociedade Portuguesa de Estomatologia e Medicina Dentária.
Published by SPEMD. This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/by-nc-nd/4.0/).

* Corresponding author.
E-mail address: joanaguerreiro123@gmail.com (Joana Guerreiro).
http://doi.org/10.24873/j.rpemd.2021.09.844
1646-2890/© 2021 Sociedade Portuguesa de Estomatologia e Medicina Dentária. Published by SPEMD.
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).