Castability and resistance of ceramometal bonding in Ni-Cr and Ni-Cr-Be alloys.
BACKGROUND
Because of its pathogenic potential, the importance of the use of beryllium with Ni-Cr alloys must be determined.


OBJECTIVE
This study compared fundamental properties for the clinical use of Ni-Cr alloys, determining the advantage of the addition of beryllium, despite the involved risks.


METHODS
Two Be-free commercial alloys (Vera Bond II and Wiron 99) and 1 Be-free experimental alloy (E3) with Nb and/or Mo in their formulations and 1 experimental Ni-Cr alloy (E4) with 1.1% Be were submitted to ceramometal bonding resistance, castability, and hardness tests.


RESULTS
Analysis of variance showed significant differences (P=.05) between Vera Bond II and Wiron 99 (Be-free) and the E4 alloy for the castability test. Vera Bond II, Wiron 99, and E4 presented higher castability values than E3. There were no statistically significant differences for the ceramometal bonding resistance test. The Kruskal-Wallis test showed significant differences (P=.01) among the alloys with Rockwell 30 T values for the hardness test.


CONCLUSIONS
Within the limitations of this study, the presence of Be in Ni-Cr alloys was not necessary to guarantee the castability and the ceramometal bond resistance of the alloys tested.
Bezzon
O L
OL
Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil. olbezzon@forp.usp.br
Ribeiro
R F
RF
Rollo
J M
JM
Crosara
S
S
D000704:Analysis of Variance; D001608:Beryllium / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry; D002858:Chromium Alloys / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry*; D001840:Dental Bonding; D003734:Dental Casting Investment / Q000737:chemistry*; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D008669:Metallurgy; D009532:Nickel / Q000737:chemistry*; D012307:Risk Factors; D018709:Statistics, Nonparametric; D013499:Surface Properties
D002858:Chromium Alloys; D003722:Dental Alloys; D003734:Dental Casting Investment; D016876:Metal Ceramic Alloys; D009532:Nickel; D001608:Beryllium