This document studied the marginal fit of zirconia copings fabricated using CAD/CAM and manual milling techniques (MAD/MAM) with different cement space widths. Marginal gaps were measured before and after cementation, and seating discrepancies were calculated. The results showed that the marginal fit of copings made via CAD/CAM vs MAD/MAM were not significantly different. The cement space width also did not significantly affect marginal fit. However, MAD/MAM copings with a 60 micron cement space did have a significantly higher seating discrepancy than those with 30 or zero micron spaces.

6. Acceptable esthetic outcome.
The high strength.
The familiar techniques.

7. Some allergic reactions of the metal alloys.
Gingival discoloration around the metal margins.

8. YPS zirconia is ceramic material that cannot be processed
in to shapes without the use of milling techniques.
Therefore, the development of high strength all ceramic core
materials such as ytrrium partially stabilized(YPS) zirconia
was mandatory

12. CAD/CAM.
MAD/MAM.
 Zero.
 30 µm.
 60 µm.

15.  For CAD /CAM technique:
pre-sintered YPS
zirconia blocks “VITA In-Ceram 2000 YZ” for crowns.

16.  For MAD/MAM technique:
Zirkonzahn system was used for the manual aided
designing and the manual aided milling of green YPS
zirconia blocks (36 x 75 mm).

18. I-CAD/CAM
(15)
a-Zero
(5)
b-30µm.
(5)
c-60µm.
(5)
II-MAD/MAM
(15)
a-Zero
(5)
b-30µm.
(5)
c-60µm.
(5)

21. For MAD/MAM technique, another 2 Stainless Steel dies
were machined with the same criteria as the main master
die but with increased diameters and heights to
compensate for the application of the die spacer.

22. • A Laser visible stone die.
• For CAD/CAM
An impression
of the main
master die.
• 3 stone dies.
• For MAD/MAM
Three
impressions of
the three steel
dies.
• 30 epoxy dies.
• For measurements.
Thirty
impressions of
the main
master die .

23. I) CAD/CAM technique (CEREC inLab):

25. Insertion axis.
Margin placement.
Coping thickness (0.5 mm).
The cement space.

28. Milling preview

30. MC XL unit
Cylinder bur 20 Step bur 20

39.  Finally, sintering of the copings were carried out using the
Zirkonofen 600 sintering oven according to the manufacturer
recommendations:
-Final temperature [°C]: 1500
-Heating period [h] (von RT): ~3h (~ 8°C/min)
-Cool down Time: 4°C/min, down to 800°C.

43. Stereomicrograph of MAD/MAM
coping.
Stereomicrograph after
automatic correction of
brightness and contrast.
Stereomicrograph after
conversion in to 8- bit
monochrome image for
detection of grey scale of
the vertical gap.
Binary threshold
of the coded areas
was done prior to
calculation of vertical
gap distance

44. Surface treatment.
Mixing and cementation using glass ionomer cement.
Loading .

45. 9- Postcementation measurements of
the cervical vertical marginal
discrepancies.

47. Using Graphpad Prism-4 statistics software:
T-test analysis was carried out between milling
techniques as function of cement spaces before/after
cementation and seating discrepancy.
One way analysis of variance ANOVA was used to
examine effects of different cement spaces on the marginal
accuracy.
P values ≤ 0.05 are considered to be statistically significant
in all tests.

48. I-Effect of milling technique regardless of the
cement space:
a- Before cementation:
0
20
40
60
80
100
Cerec In-Lab Zirkon Zahn
81.04 84
Totalmarginalgap(µm)

49. b- After cementation:
0
20
40
60
80
100
120
Cerec In-Lab Zirkon Zahn
102.4 99.54
Totalmarginalgap(µm)

50. c-Seating discrepancy:
0
5
10
15
20
25
Cerec In-Lab Zirkon Zahn
20.96
15.57
Totaldiscrepancy(µm)

51. II-Effect of milling technique regarding cement
space zero:
a- Before cementation:
0
20
40
60
80
100
Cerec In-Lab Zirkon Zahn
86.95
91.93
Marginalgap(µm)

52. b- After cementation:
0
20
40
60
80
100
120
Cerec In-Lab Zirkon Zahn
109.4
103.4
Marginalgap(µm)

53. c- Seating discrepancy:
0
5
10
15
20
25
Cerec In-Lab Zirkon Zahn
21.25
11.53
Discrepancy(µm)

54. II-Effect of milling technique regarding
cement space 30 µm:
a- Before cementation:
0
10
20
30
40
50
60
70
80
90
Cerec In-Lab Zirkon Zahn
85.61 84.66
Marginalgap(µm)

55. b- After cementation:
0
20
40
60
80
100
120
Cerec In-Lab Zirkon Zahn
107
100
Marginalgap(µm)

56. c- Seating discrepancy:
0
5
10
15
20
25
Cerec In-Lab Zirkon Zahn
21.39
15.37

57. III-Effect of milling technique regarding
cement space 60 µm:
a- Before cementation:
0
10
20
30
40
50
60
70
80
Cerec In-Lab Zirkon Zahn
70.56
75.41
Marginalgap(µm)

58. b- After cementation:
0
20
40
60
80
100
Cerec In-Lab Zirkon Zahn
90.8
95.22
Marginalgap(µm)

59. c- Seating discrepancy:
0
5
10
15
20
25
Cerec In-Lab Zirkon Zahn
20.23 19.81
Discrepancy(µm)

60. V-Effect of cement space on the marginal
accuracy of CAD/CAM copings:
a- Before cementation:
0
20
40
60
80
100
Space 0 Space 30 Space 60
86.95 85.61
70.56
Marginalgap(µm)

61. b- After cementation:
0
20
40
60
80
100
120
Space 0 Space 30 Space 60
109.4 107
90.8
Marginalgap(µm)

62. C-Seating discrepancy:
0
5
10
15
20
25
Space 0 Space 30 Space 60
21.25 21.39
20.23
Discrepancy(µm)

63. IV-Effect of cement space on the marginal accuracy
of MAD/MAM copings:
a- Before cementation:
0
20
40
60
80
100
Space 0 Space 30 Space 60
91.93
84.66
75.41
Marginalgap(µm)

64. b- After cementation:
0
20
40
60
80
100
120
Space 0 Space 30 Space 60
103.4 100
95.22
Marginalgap(µm)

65. c- Seating discrepancy:
0
5
10
15
20
Space 0 Space 30 Space 60
Zirkon Zahn
11.53
15.37
19.81
Discrepancy(µm)

69. The marginal fit of CAD/CAM YPS zirconia copings was not
significantly different from the MAD/MAM YPS zirconia
copings.
The cement space had no influence on the marginal fit of all
copings fabricated by both milling techniques.
The cementation did not affect significantly the marginal
seating.
MAD/MAM copings with cement space 60 had the highest
significant seating discrepancy mean value followed by
cement space 30 and cement space zero.