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conferenceseries.com
May 01-02, 2017 Toronto, Canada
2nd International Conference on
Restorative Dentistry and Prosthodontics
Volume 5, Issue 1 (Suppl) J Oral Hyg Health
ISSN: 2332-0702 JOHH, an open access journal Restorative Dentistry & Prosthodontics 2017
May 01-02, 2017
J Oral Hyg Health 2017, 5:1 (Suppl)
The effect of different finish lines on marginal and internal fit of a ceramic crown fabricated by CAD/
CAM system
Alaa Elaraby
Alexandria University, Egypt
This study evaluates the marginal discrepancy of CAD/CAM ceramic coping of two different finish line preparations. Two master
steel dies were prepared, one with rounded shoulder (RS), and the other with chamfer (C). CEREC 3D Sirona CAD/CAM system
and Software Version 2.80 R2400 were used in this study. The optical camera was fixed in a distance of 10 cm and 90 degree to take the
same optical capture for each sample. CEREC cylinder pointed bur was used to cut the Ivoclar Vivadent ProCAD Milling Blocks to
fit on the dies. Twenty copings were prepared, ten CAD/CAM ceramic coping from each finish line preparation. Each coping with its
corresponding die was sectioned longitudinally using ISOMET 2000 PRECISION SAW. The marginal discrepancy was then evaluated
in Travelling Microscope. The data of marginal discrepancy in micrometer (µ) were subjected to two way analysis of variance using
SPSS version 15. The mean value of marginal discrepancy was 135.48 µm and 85.7 µm for chamfer group (C) and rounded shoulder
group (R) respectively. Furthermore, there was a significant difference in the axial fitting on the occlusal side (occlusal adaptation)
of the crowns between the chamfer and shoulder groups (p<0.05). Shoulder group showed the lowest mean value of 95.84 µ ± 15.02,
while chamfer recorded the highest value of 137 µ ±13.09. The results showed that there was a significant difference between the two
groups. It was concluded that marginal fit of CAD/CAM all-ceramic crowns with rounded shoulder finish line had better adaptation
than chamfer finish line. The adaptation of CAD/CAM crowns obtained with chamfer finish line was not clinically accepted.