Fracture load of CAD/CAM-fabricated and 3D-printed composite crowns as a function of material thickness

Clin Oral Investig. 2019 Jun;23(6):2777-2784. doi: 10.1007/s00784-018-2717-2. Epub 2018 Oct 27.


Objectives: Indirect CAD/CAM restorations can be fabricated using both subtractive and additive CAD/CAM technology. This study investigated the fracture load of crowns fabricated from three particle-filled composite CAD/CAM materials and one 3D-printed composite material.

Materials and methods: Lava Ultimate, Cerasmart and Brilliant Crios were used as particle-filled composite CAD/CAM material and els-3D Harz as 3D-printed composite material. For each group, crowns with three different material thicknesses (0.5/1.0/1.5 mm) were fabricated. Control group was composed of ceramic-based CAD/CAM materials e.max CAD and Enamic. Totally, n = 180 crowns were fabricated and adhesively seated on SLA fabricated dies. Thermomechanical loading and fracture testing were performed. The data for fracture loading force were statistically analyzed by two-way ANOVA followed with multiple comparisons by post hoc Tukey's test (α = 0.05).

Results: In contrast to ceramics, all particle-filled composite crowns with 0.5-mm thickness survived fatigue testing. Forces varied statistically significantly. Brilliant Crios showed highest maximum loading force with 1580.4 ± 521.0 N (1.5 mm). Two-way ANOVA indicated that both the material and the thickness affected the fracture load (p < 0.05).

Conclusions: Particle-filled composite resin CAD/CAM materials may have advantageous material characteristics compared to ceramic CAD/CAM materials for minimal restoration thicknesses.

Clinical relevance: Composite-based CAD/CAM materials may offer new possibilities in minimally invasive restorative treatment concepts.

Keywords: 3D printing; CAD/CAM; CEREC; Hybrid ceramic; Lithium disilicate ceramic; Particle-filled composite; Resin nano ceramic.

MeSH terms

  • Ceramics
  • Composite Resins
  • Computer-Aided Design
  • Crowns*
  • Dental Porcelain*
  • Dental Restoration Failure*
  • Materials Testing
  • Printing, Three-Dimensional
  • Stress, Mechanical


  • Composite Resins
  • Dental Porcelain