Table 2.

Comparison of marginal gap between the crowns fabricated by conventional and computer-aided design and computer-assisted manufacturing techniques (μm)

Surfaces	Method	Mean	Mean rank	Sum of ranks	Mann-Whitney U	P
Buccal	CAD-CAM	42.68	11.43	171.50	51.500	0.011*
	Conventional	52.46	19.57	293.50
Mesiobuccal	CAD-CAM	15.94	11.03	165.50	45.500	0.005**
	Conventional	30.13	19.97	299.50
Mesial	CAD-CAM	21.26	13.87	208.00	88.000	0.306
	Conventional	29.22	17.13	257.00
Mesiolingual	CAD-CAM	29.59	13.30	199.50	79.500	0.171
	Conventional	41.88	17.70	265.50
Lingual	CAD-CAM	42.04	14.43	216.50	96.500	0.507
	Conventional	42.92	16.57	248.50
Distolingual	CAD-CAM	26.70	12.23	183.50	63.500	0.042*
	Conventional	43.86	18.77	281.50
Distal	CAD-CAM	12.38	11.17	167.50	47.500	0.006**
	Conventional	31.45	19.83	297.50
Distobuccal	CAD-CAM	24.11	12.83	192.50	72.500	0.097
	Conventional	38.76	18.17	272.50

*P<0.05, **P<0.01. CAD-CAM=Computer-aided design and computer-assisted manufacturing