Methods: A new self-adhesive composite cement (exp. GAM-200, GC) and a self-etch composite cement (Multilink Automix, Ivoclar-Vivadent) were used to bond feldspathic ceramic blocks (Vita Mark II, Vita) onto bur-cut flat enamel and mid-coronal dentin surfaces. Teeth were distributed randomly in two experimental groups per cement according to storage time. After 1-week or 6-month of water storage (37°C), specimens were prepared to determine the ‘immediate’ and ‘aged’ µTBS, respectively. Failure patterns were evaluated using a stereomicroscope, and afterwards imaged using Feg-SEM.
Results:
|
exp. GAM-200 |
Multilink Automix |
||
|
1 week |
6 months |
1 week |
6 months |
µTBS to ENAMEL |
13.6±5.1B |
11.6±5.5B |
21.6±5.6A |
24±8.4A |
ptf/n |
0/40 |
0/40 |
0/40 |
0/40 |
µTBS to DENTIN |
10.8±3.0a |
10,4±5.4a |
4.3±4.6b |
1.8±5.6b |
ptf/n |
0/40 |
0/40 |
16/39 |
34/40 |
Same superscripts indicate absence of significant difference (Tukey HSD; p<0.05) |
||||
Two-way ANOVA revealed significant differences for the variable ‘luting composite’. The µTBS to enamel did not decrease upon ageing for both luting composites tested, while that of the self-etch composite cement Multilink Automix (Ivoclar-Vivadent), which makes use of a separate self-etch primer, remained significantly higher than that of the experimental self-adhesive composite GAM-200 (GC). While the µTBS to dentin did also not decrease upon ageing for both luting composites tested, the experimental self-adhesive composite GAM-200 outperformed the self-etch composite cement Multilink Automix (Ivoclar-Vivadent).
Conclusions: Bond durability of both luting composites tested was not affected, while contrasting data were recorded when bonded to either enamel or dentin.