D.U. ADEOLA, K.L. O'KEEFE, L.M. PINZON, and J.M. POWERS, University of Texas Health Science Center at Houston Dental Branch, Houston Biomaterials Research Center, USA
Objectives: To
study the effect of cement and alloy on the tensile bond strength of high noble
and two types of base metal casts posts to tooth structure. Methods: Teeth were sectioned
perpendicular to the long axis at the cemento-enamel junction. Root canals were
reamed with a precision drill press (Kavo) set to a drilling depth of 8 mm and
randomly divided into 12 groups (n=8). A post pattern was fabricated for each
specimen using a plastic dowel. Each pattern was cast in one of 3 alloys [Type
IV gold (G), nickel-chromium (N), and chromium-cobalt (C)] according to the
manufacturer's instructions. The castings were divested and cleaned with 50-um
aluminum oxide. Posts were cemented with one of 4 cements [Post Cement HI-X,
Bisco (PC); Cement-It, Pentron (CI); Panavia F, Kuraray (PF); and Zinc
Phosphate, Harvard Cements (ZP)]. Specimens were stored in water at 37° C for
24 hours. They were debonded in tension with an Instron testing machine at a
cross-head speed of 0.5 mm/min. Tensile strength (MPa)
values were calculated. Results: Means
(standard deviations) are listed. Fisher's PLSD intervals (p=0.05) for
comparisons of cements and alloys were 1.7 and 1.5 MPa.
|
|
PC
|
CI
|
PF
|
ZP
|
|
G
|
13.9(2.7)
|
8.3(2.9)
|
5.9(3.0)
|
8.4(3.1)
|
|
N
|
7.0(3.4)
|
8.5(3.6)
|
6.9(2.1)
|
8.8(2.9)
|
|
C
|
10.1(2.8)
|
10.2(3.7)
|
9.0(2.8)
|
8.6(2.5)
|
Conclusions: PC
with G had the highest bond strength of any groups. For G,
PC>CI=ZP>PF. For N, ZP=CI and
CI=PF=PC. For C, PC=CI=PF=ZP. ZP showed
no significant difference among alloy groups. Funded by Pentron Laboratory
Technologies. Products provided by manufacturers.
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