The purpose of this study was to evaluate the influence of ageing by thermo-cycling on the shear bond strength (SBS) of different adhesive types.
Method:
Human molars were randomly divided into 12 groups (n=8). 48 flat enamel and 48 flat dentine surfaces were prepared on SiC paper grit 120 through grit 320. Adhesives used in this study were iBOND Self Etch (IBSE) and iBOND Total Etch (IBTE, both Heraeus Kulzer). The adhesives were used according manufacturer’s instruction. Venus Diamond composite, shade A2, was bulk filled in cylindrical plastic molds (Ultradent equipment) and cured for 20s. Both, adhesive and composite were cured separately using a LED LCU (Translux Power Blue, Heraeus Kulzer). SBS was determined before (control groups), after 5,000 and after 10,000 cycles thermo-cycling (5°/55°C water bath, immersion time 30s and transfer time 5s) using a universal testing device (crosshead speed 1mm/min). Statistical analysis was done by ANOVA at p<0.05.
Result:
Mean SBS [MPa] and standard deviation on enamel/dentine before and after thermo-cycling:
|
enamel |
dentine |
||
|
iBSE |
iBTE |
iBSE |
iBTE |
control |
26.2±4.7 a |
30.4±13.5 a |
36.4±5.3 A,B |
24.4±8.6 a,b |
5,000 thermo-cycles |
28.0±5.7 a |
32.1±11.3 a |
38.1±5.9 A |
35.0±16.0 b |
10,000 thermo-cycles |
27.5±5.8 a |
29.7±9.5 a |
32.2±5.4 B |
21.7±12.7 a |
Different letters show statistical significant discrepancies within columns.
Conclusion:
Within the limits of this study it can be concluded that shear bond strength of iBSE and iBTE seems to be not affected by ageing with 10,000 thermo-cycles. Study done by Heraeus.