Abstract
PURPOSE: This study investigated the influence of the fiber sleeve on push-out bond strength (PBS), both with and without aging in a mastication simulator. MATERIALS AND METHODS: Sixty straight-rooted mandibular premolars were randomly divided into four groups (n = 15). Groups S and S(MS) included fiber sleeves and posts, while Groups P and P(MS) included posts only. Groups S(MS) and P(MS) underwent aging in a mastication simulator (50 N load, 240,000 cycles). Specimens were sectioned into 1 mm slices (coronal, middle, apical thirds), and PBS testing was performed using a universal testing machine. Failure modes were analyzed under 40× magnification. Statistical analysis used one-way ANOVA and Tukey tests (α = 0.05). RESULTS: Group S had the highest PBS, significantly surpassing Group P (P < 0.001). Aging significantly reduced PBS in sleeve groups (S vs. S(MS,) P = 0.029) Adhesive failure between dentin and cement was most common. CONCLUSION: The use of fiber sleeves significantly improved PBS; however, this enhancement diminished following aging procedures.