At both 0.25 and 0.5 mm thicknesses , powder-liquid based opaquer ( Sinfony ) showed significantly higher results ( 8.4 + / -5.6 and 8.4 + / -4.9 MPa , respectively ) than those of other opaquers ( 1.4 + / -1 to 4.3 + / -3.8 MPa ) ( p < 0.05 ) .
