Objective: To evaluate the SBS of five surface treatments on two high alumina-content ceramic cores (AC and IN) cemented with two resin cements Nexus (NX), and Panavia P21 TC (P21).
Method: 5 mm long cylinders of each core were made in two diameters (4 and 6 mm), polished to 1200 grit and subjected to five treatments: 1) 25-µm Al2O3 at 90 psi (AH), 2) 50-µm Al2O3 at 36 psi (AL), 3) 30-µm SiO2 at 80 psi + silane (Cojet, CJ), 4) HF at 9.5% (HF), 5) tin coating (SN) and 6) control (CO). Groups of 12 were bonded, thermocycled for 37,500 cycles (5°-55°C) and shear tested to failure. SBS data were analyzed with 3-way ANOVA and Tukey’s multiple comparisons.
Result: Mean (MPa) and SD are shown below:
|
AH |
AL |
CJ |
HF |
SN |
CO |
|
|
AC-NX |
1.24 ± 1.56 |
0.93 ± 0.71 |
5.75 ± 4.95 |
2.89 ± 2.37 |
3.97 ± 2.44 |
2.53 ± 2.67 |
|
AC-P21 |
44.57 ± 18.04 |
40.96 ± 11.97 |
53.84 ± 10.02 |
22.34 ± 5.53 |
25.83 ± 10.68 |
23.23 ± 8.25 |
|
IN-NX |
3.68 ± 5.06 |
11.65 ± 8.26 |
34.59 ± 15.31 |
3.36 ± 3.93 |
6.67 ± 4.93 |
5.11 ± 1.79 |
|
IN-P21 |
54.45 ± 8.05 |
54.21 ± 14.15 |
36.59 ± 10.30 |
32.09 ± 5.81 |
50.08 ± 14.35 |
30.16 ± 9.68 |
Conclusion: Using 30 MPa for a minimum SBS: 1) NX with AC with any of the tested treatments did not yield satisfactory SBS; when bonding NX to IN only CJ was effective. 2) AH, AL and CJ produced satisfactory SBS when bonding AC with P21; AH, AL, and SN were satisfactory bonding IN with P21. 3) HF did not perform better than CO. 4) P21 produced the highest SBS with either core. 5) All specimens exhibited adhesive failures. 6) AH or AL with P21 yield best results for either core.