Effect of mechanical cleaning protocols in the fiber post space on the adhesive interface between universal adhesive and root dentin

The aim of this study was to evaluate the effects of cleaning protocols on the presence of residues, open dentinal tubules, and bond strength of a self‐etch adhesive plus a dual‐cure resin cement to dentin in the fiber‐post space. The methods for cleaning utilized were conventional irrigation (CI), rotary brush with continuous rotary movement (RB), and continuous ultrasonic irrigation (CUI). Sixty bovine incisors were used for fiber‐post space preparation. Thirty roots were divided into three groups (n = 10) according to the cleaning protocols and submitted to scanning electron microscope to evaluate presence of residues and relative quantity of open dentinal tubules on dentin surface. Similar protocols were performed in the other thirty roots (n = 10) using a self‐etching adhesive system (Scotchbond Universal) and a dual‐cure resin cement (Relyx Unicem 2). After 6 months cervical, middle, and apical thirds sections of fiber‐post space were submitted to push‐out testing. To data ANOVA and Tukey's test were employed (α = 5%). RB and CUI showed the lowest presence of residues on dentin surface (p = .015) and the highest bond strength values (p