Methods: Six samples per test (5x2 mm for VHN and dimensional changes and 2x2x25 mm for Fs) were prepared in each of the following groups: Biodentine, conventional glass-ionomer cement (Fuji IX, GC), resin-modified GIC (Vitrebond, 3M ESPE), flowable (Vertise Flow, Kerr) and nanohybrid composite (Filtek Supreme XT, 3M ESPE). Samples were either cured with a high-power LED light-curing unit (Elipar S10, 3M ESPE) or left to set in case of Biodentine and Fuji IX. VHN and Fs were measured 24 h and 21 days post-curing/setting. Fs was tested according to the ISO 4049 standard in a three-point bending setup. Dimensional changes were measured using a two-camera system (Aramis GOM) based on digital image correlation. Digital images were taken before and after material curing/setting. Data were statistically analyzed using analysis of variance and paired t-tests at α=0.05.
Results: VHN values of Filtek Supreme (87.1±3.1) and Biodentine (82.7±3.8) were significantly higher compared to Vertise, Vitrebond and Fuji IX (p<0.05). Only Biodentine exhibited increased VHN after storage (88.8±4.8, p<0.001). Fs of Biodentine (8.8±2.4 MPa) was comparable to Fuji IX (8.7±3.0 MPa) but significantly lower than resin-based materials (p<0.05). Similarly to VHN, only Biodentine showed significantly increased Fs after storage (p<0.05). Two distinctive zones of shrinkage were identified in all materials, a central zone involving major part of the sample and a peripheral zone of circa1 mm. Significantly lower shrinkage occurred in Biodentine (1.23±0.96% peripherally and 0.82±0.48% centrally) compared to other materials (p<0.05).
Conclusions: Within manufacturer’s recommendations, Biodentine may be considered an adequate restorative material in the range of currently used GICs and composites.