Flexural strength of Cerec 2 machined and jointed InCeram-Alumina and InCeram-Zirconia bars.
OBJECTIVE
The flexural strength of Cerec 2 InCeram-Alumina and InCeram-Zirconia bars is evaluated. The focus of the in vitro study is to identify a jointing procedure for InCeram which may be used for producing full-ceramic fixed-partial-denture frameworks.


METHODS
Six groups (n=15) of machined and jointed InCeram-Alumina (T1-T5) and InCeram-Zirconia (T6) bars (3x4x13mm(3)), respectively, were examined using a 3-point-bending test. InCeram-Alumina joint-free controls were: machined (C1), slip cast (C2, C3) and cut from the block (C4) bars. Machined joint-free InCeram-Zirconia bars were used as controls (C5). InCeram-Alumina slip was used for jointing T1-T5 and InCeram-Zirconia slip for bars T6. Bars were jointed in groups T1 and T2 using butt joint (S1), in T3 and T4 oblique (S2, S3) and in T5 and T6 rounded (S4) joint shapes.


RESULTS
Two-way analysis of variance showed significant differences between materials (p<0.001) and jointing shapes (p<0.001). The rounded (S4) shape showed the highest flexural strength of 434 (65) MPa of InCeram-Alumina (T5) and 475 (54) MPa of InCeram-Zirconia (T6) bars, respectively but machined/joint-free InCeram-Alumina (511 (59) MPa, C1) and machined/joint-free InCeram-Zirconia (624 (58) MPa, C5) were significantly (p<0.01/p<0.001) stronger. No significant differences (p>0.05) were found between machined/jointed InCeram-Zirconia (475 (54) MPa, T6), joint-free InCeram-Alumina slip cast (498 (125) MPa, C2) and joint-free InCeram-Alumina machined bars (511 (59) MPa, C1).


CONCLUSIONS
Compared to conventional slip cast InCeram-Alumina the flexural strength of machined/jointed InCeram-Zirconia appears to be adequate for fixed-partial-denture frameworks.
Apholt
W
W
Division of Aesthetic and Computer Restorations, Department of Preventive Dentistry, Periodontology and Cariology, Center for Dental and Oral Medicine, University of Zurich, Switzerland.
Bindl
A
A
Lüthy
H
H
Mörmann
W H
WH
D000537:Aluminum Oxide / Q000737:chemistry*; D000704:Analysis of Variance; D002516:Ceramics / Q000737:chemistry*; D017076:Computer-Aided Design; D003735:Dental Casting Technique; D003764:Dental Materials / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry*; D003830:Denture, Partial, Fixed; D005898:Glass / Q000737:chemistry; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D018583:Pliability; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties; D015040:Zirconium / Q000737:chemistry*
D003764:Dental Materials; D003776:Dental Porcelain; C074543:Cerec; C070870:In-Ceram; D015040:Zirconium; D000537:Aluminum Oxide; C028541:zirconium oxide