Table 6.

The results of adhesive/cohesive failure modes of the experimental groups.

Category	A	B	C	D	E
Group 1	0	5	0	3	0
Group 2	1	2	2	3	0
Group 3	5	0	0	3	0
Group 4	7	0	0	0	0
Group 5	8	0	0	0	0
Group 6	0	0	0	6	2
Group 7	0	2	0	4	2

Category A: The titanium bonding base is covered with a visible cement film; the inner part of the zirconium dioxide crown is not. Category B: The inner part of the zirconium dioxide crown is covered with a visible cement film; the titanium base is not. Category C: The titanium bonding base and the inner part of the zirconium dioxide crown are covered with a visible film of cement. Category D: The surfaces of both the titanium bonding base and the zirconium dioxide crown are partially exposed or not. Category E: Hardly any of the zirconium dioxide and titanium surfaces are covered with a visible film of cement.