Method: Eighteen roots of bovine teeth were used (n=6). Crowns were removed and roots were embedded in polystyrene resin blocks and sectioned, leaving the root portion with 20 mm. Dental root canals were prepared using burs system provided by fiber post manufacturer (WhitePost, FGM), allowing a uniform post space. Posts were silanated (Prosil, FGM) and the root canal was lubricated with a water-soluble glycerin gel to allow the fiber posts relined with composite resin (Z100, 3M ESPE). Three adhesive cementation protocols were evaluated: etch-and rinse adhesive system (Scotchbond Multi Purpose, 3M ESPE) followed by RelyX ARC resin cement (3M ESPE) (SBMP+ARC); self-adhesive resin cement (RelyX Unicem 2, 3M ESPE) (RU2) and multi-mode adhesive (Scothbond Universal, 3M ESPE) followed by resin cement (RelyX Ultimate, 3M ESPE) (SBU+ULT). Roots were sectioned and evaluated at four depths (cervical to apical), by push-out test, which was performed in a universal testing machine (Instron 4411) until bond failure (0.5mm/min). Data were analyzed using a two-way split-plot ANOVA and Tukey test (p≤0.05).
Result: Table 1. Means (SD) of PBS according to the group and depth (I=cervical;II=cervical/medium;III-medium/apical;IV-apical).
Depth |
Group |
||
|
SBMP+ARC |
RU2 |
SBU+ULT |
I |
5.8 (1.8)Aa |
7.8 (1.8)Aa |
6.5 (3.4)Aa |
II |
4.1 (2.2)Aab |
6.23 (1.7)Aab |
7.1 (2.7)Aab |
III |
3.9 (2.5)Abc |
5.1 (1.2)Abc |
5.7 (3.3)Abc |
IV |
3.1 (1.7)Ac |
4.1 (2.0)Ac |
3.1 (1.8)Ac |
Means followed by different letters (upper case in the row and lower case in the columns) are significant different (p<0,05).
Conclusion: No statistical differences were found in PBS for different adhesive cementation techniques of relining fiber glass posts to dentin roots. PBS decreased according to increasing depth of fiber glass posts for all cementing systems tested.