Effect of cements on fracture resistance of monolithic zirconia crowns

Figures & data

Figure 1. Schematic representation of measuring points in micro-CT analysis. Crown thickness and cement space were measured as the vertical distance at 10 different points (A–J). The minimal occlusal thickness was obtained at B, F and I.

Figure 2. Compressive strength of cements tested. Different letters above the columns show significant differences (p < 0.01). ZPC, zinc phosphate cement; GIC, glass-ionomer cement; SRC, self-adhesive resin-based cement; RC-D, resin-based cement (dual cure mode); RC-C, resin-based cement (chemical cure mode).

Figure 3. Representative micro-CT images of (a) bucco-lingual aspect and (b) mesio-distal aspect.

Table 1. The mean values (SD) of crown thickness and cement space.

	A	B	C	D	E	F	G	H	I	J
Crown thickness (μm)	1020	523	1065	672	666	525	652	1101	553	1091
	(23)	(6)	(3)	(22)	(5)	(20)	(16)	(28)	(16)	(25)
Cement space (μm)	130	125	123	125	139	137	144	119	113	112
	(10)	(4)	(15)	(11)	(2)	(8)	(8)	(22)	(25)	(21)

A–J correspond to the measuring points shown in Figure 1.

Figure 4. Fracture resistance of monolithic zirconia crowns cemented to dies using different cements. One-way ANOVA revealed that there was no significant difference between the groups. ZPC, zinc phosphate cement; GIC, glass-ionomer cement; SRC, self-adhesive resin-based cement; RC-D, resin-based cement (dual cure mode); RC-C, resin-based cement (chemical cure mode).

Figure 5. Representative SEM image of fractured monolithic zirconia crown. The fractographic features (i.e. fracture mirror, mist and hackles) indicated that the fracture origin was located at occlusal surface. The dotted arrows indicate the direction of the fracture wave.