Methods: The restorative systems tested were Chemfil-Rock (CFR) and Equia-Fil (EFC). For strength, VHN (3 kp/15s) was measured on the flat surfaces of disc-shaped specimens (Ø:8mm, h:2 mm, n:10 per group) 24h after setting at 37o/95%RH. For Equia-Fil, measurements were performed with (EFC) and without Equia-Coat (EFX). The crack length radiating from indentation angles was measured by reflected light microscopy. The surface topography of the specimens was evaluated by reflected light microscopy and ESEM. For cavity adaptation measurements, class I cavities (2mm lengthx3mm depthx1,5mm width, n:5 per group) were prepared in upper premolars extracted for orthodontic reasons, restored with the restorative systems according to the manufacturers’ instructions (CF:no cavity conditioner, no surface coat, EF: with cavity conditioner and surface coat) and studied by X-ray microtomography.
Results: The results of VHN were (mean/sd): CFR:76.17(3.63); EFC: 71.88 (11.65); EFX:33.57(6.66). CFR showed much less crack length radiating from the indentation angles in comparison to EFX. Nevertheless, the only crack-free surface observed was that of EFC. The percentage void volume calculated from the micro-XCT was 0,05 (0,03) for EFC and 2.15 (1.10) for CFR the difference being statistically significant. 2 and 3-D reconstructions showed that porosity for CFR was mainly located at the internal cavity margins (pulpal, axial angles).
Conclusions: Although strong, some reinforced glass-ionomer restoratives may create adaptation problems due to increased porosity, mostly attributed to the material viscosity.