Mechanical property characterization of a novel directlyplaced ceramic restorative material

Purpose: To compare, in vitro, the mechanical properties of a directly-placed ceramic restorative material (Doxadent) to glass-ionomer (Fuji IX), hybrid composite control (Z250) and amalgam control (Tytin). Diametral tensile strength (DTS), compressive strength (CS), and Vickers hardness number (VHN) were measured for 10 specimens per group (n= 480 total) with time (1 hour, 24 hours, 1 week, 4 weeks). CS and DTS specimens were cylinders (4x8 mm). VHN specimens were disks (9.5 x 1 mm). Specimens were prepared following manufacturers' instructions, stored in deionized water (37 ^°C), and tested in 100% humidity (23 ^°C). CS and DTS specimens were loaded to failure (Instron, CHS= 0.5mm/minute). VHN discs were indented. Data were analyzed using ANOVA and Tukey's test (P< 0.05) for pairwise comparisons of group means at each time. In CS and DTS, DoxaDent was weakest (P< 0.05) for all testing times except Fuji IX DTS at 1- and 4-week intervals. For VHN, DoxaDent was harder than glass-ionomer, better than composite except at 1 hour and less than amalgam. Except for VHN for Z250, all values improved from 1-24 hours. Based on current in vitro results, this novel restorative material does not yet equal composite or amalgam CS or DTS.