الفهرس 
Marginal accuracy and internal adaptation of poly ether ether ketone single crowns fabricated by two different techniques : An in-vitro study
ABSTRACTOnly 14 pages are availabe for public view
 |  | from | 118 |  |  |
| | | from | 118 | | |
Abstract
Statement of the problem: Polyetheretherketone (PEEK) as a fixed dental prosthesis has been
widely used, however insufficient information is available to compare the precision of the margin
and internal fit of this material as a function of different construction techniques.
Aim: To evaluate the influence of different fabrication techniques on the marginal accuracy and
internal adaptation of PEEK molar single-crowns.
Materials and Methods: 20 PEEK crowns are constructed by 2 different fabrication methods and
divided in to 2 groups n=10 (PEEK CAD and PEEK Pressed). PEEK CAD crowns were numbered
from 1-10 While PEEK Pressed crowns were numbered from 11-20, where each group has 10 crowns
and both are constructed over a master die. For the PEEK CAD crowns, the master die was sprayed
with scan spray and scanned by 3shape E4 scanner TRIOS®3. And designing was done by
Ceramill4E2 Exocad CAD/CAM Software and using 4 –axis milling machine. For the PEEK
pressed crowns, Wax copings were milled using same STL file with the same dimensions used for
scanning, designing, and milling of the previously constructed CAD-CAM PEEK Crowns. Silicone
replica bodies were constructed and sectioned in bucco-lingual direction into 2 halves for internal fit
measurements and marginal accuracy was measured by using 3 equidistant landmarks along the
cervical circumference for each surface of the specimen using digital microscope. Each specimen was
photographed using The Microscope Leica L2 APO* at magnification 16 X which is connected to
acer computer where images are processed by Leica Application suite (LAS) Version 4.0 software.Results: For Marginal accuracy, PRESS group recorded statistically significant higher marginal
gap mean value than CAD group. So Milled PEEK showed better marginal precision than pressed
ones. For Internal fit, no statistically significant difference between CAD group and PRESS group
was recorded. At significance value (2 tailed P- value) =0.21 (p>0.05).
Conclusions: PEEK CAD crowns showed superior marginal accuracy and almost equal in internal fit
compared to PEEK pressed crowns. Both materials showed marginal accuracy and internal gap values
within the clinically acceptable values which are less than 120µm.