DOI: 10.3290/j.qi.a44147, PubMed ID (PMID): 32128525Pages 268-273, Language: EnglishRizzante, Fabio A. P. / Soares-Rusu, Idiane B. L. / Senna, Suellen S. / Ramos-Tonello, Carla M. / Mondelli, Rafael F. L. / Ishikiriama, Sérgio K. / Borges, Ana Flávia S. / Gutmacher, ZviObjective: The objective of the present study was to assess the effect of monolithic and bilayer restorations considering heat-pressed and milled/CAD/CAM reinforced lithium disilicate ceramic veneers, on the flexural strength after cementation.
Method and materials: Thirty-five specimens were divided into five groups (n = 7), according to the restorative solution: 2-mm thickness composite resin (CR2); heat-pressed monolithic ceramic 0.6 mm (HPM), CAD/CAM monolithic ceramics 0.6 mm (CCM); heat-pressed monolithic ceramic 0.4 mm + 0.2 mm glass-ceramic (HPB); CAD/CAM monolithic ceramic 0.4 mm + 0.2 glass-ceramic (CCB). Specimens were cemented on composite resin bars and submitted to a three-point bending test on a Universal Testing Machine, until fracture. Fractured samples were analyzed under stereomicroscope and SEM. Flexural strength data were analyzed by one-way ANOVA and Tukey test.
Results: The control group showed the highest flexural strength results (119.57 ± 19.49 MPa), with values similar to groups HPM (98 ± 25.62 MPa) and CCM (96.14 ± 20.60 MPa). Groups HPB and CCB showed lower values when compared with the other groups. Fracture started from the base on monolithic groups and from ceramic on bilayer groups.
Conclusion: Both ceramic systems (CAD/CAM and heat-pressed) have similar fracture strength, although bilayer restorations present lower strength when compared with monolithic ceramics.
Keywords: CAD/CAM, ceramics, dental materials, esthetics, operative dentistry, prosthodontics, veneers
