Fracture toughness of conventional, milled and 3D printed denture bases.

Objectives: The aim of this study was to determine and compare fracture toughness (K) and work of fracture (WOF) of a conventional (C) denture base, using the notchless triangular prism (NTP) specimen K test, with CAD/CAM (milled, M) and 3D-printed (P) materials at 7 d and 90 d.

Methods: Lucitone 199 (C), Lucitone 199 CAD (M) and Lucitone Digital Print (P) (Dentsply, USA) were used to fabricate NTP specimens. Samples were stored in 37 °C water for 7 d (20/group) and 90 d (20/group) and conditioned in 23 °C water for 1 h prior to testing.