Effect of Different Adhesive Strategies on Bond Quality of Fiber Posts Cemented in Endodontically Treated Teeth

The purpose of this in vitro study was to assess the effects of anatomic root levels, different adhesive strategies and cementation system on bond strength (BS), nano leakage (NL) and degree of conversion (DC) after fiber posts cementation.

Sixty-six roots of human premolars were endodontically prepared and divided according to the combination of adhesive application technique (manual passive, manual active and active vibratory) and the cementation system (Adper Single Bond 2/RelyX ARC [SBAR] and Single Bond Universal/RelyX Ultimate [SBUL]). Specimens were transversally sectioned into six 1-mm-thick serial slices, which were subjected to BS testing (n=7), to NL analysis using scanning electron microscopy (SEM) after slice immersion in silver nitrate (n=2), and micro-Raman spectroscopy for DC (n=2). Data were analyzed using two-way ANOVA and Bonferroni post-hoc test (α=5%).

Bond strength values significantly increased with active vibratory application technique (P<0.001), no significant difference was noted between adhesive systems. The cementation system Single Bond Universal/RelyX Ultimate demonstrated the lowest nano leakage values (P<0.05). The manual active and vibratory application techniques showed statistically higher degree of conversion values than the manual passive technique at the coronal and medium thirds (P<0.05); and the lowest results were observed with manual passive application to Single Bond Universal/RelyX Ultimate (P=0.016).

The study concluded that techniques with active application (vibratory and manual) resulted in higher bond strength values. The mode of adhesive application influence the results.