An in vitro study on the adhesion of quartz fiber posts to radicular dentin

Purpose: To evaluate in vitro the bond strength at the adhesive interface between a quartz fiber post, different adhesive systems, and different composite cements. Materials and Methods: Thirty extracted single-rooted teeth were endodontically treated and divided into three groups (n = 10). Quartz fiber posts (DT Light-Post) were cemented with the following materials: group I: Prime & Bond NT + Self Cure Activator, and Calibra as luting cement; group II: Prime & Bond NT + Self Cure Activator, and UniFil Core; group III: UniFil Bond in combination with Unifil Core. The specimens were processed for the push-out test to evaluate bond strength at the root dentin-cement-post interface. They were sectioned along the long axis of the post into 1-mm-thick slices. A total of 60 sections was obtained from group I. Group II provided 67 slices, while group III provided 69. Loading was performed at a crosshead speed of 0.5 mm/min until the post segment was dislodged from the root section. Results: There was no statistically significant difference between the three experimental groups. The mean bond strength obtained for group I was 9.81 ± 5.40 MPa. For group II it was 12.06 ± 6.25 MPa, and 9.80 ± 5.01 MPa for group III. Conclusion: All the materials tested were similar in terms of providing satisfactory bond strength when used for luting fiber posts. However, Unifil Core may be advantageous since it can also be used as a core buildup material, which simplifies the clinical procedures. Keywords: dental adhesives, resin cements, fiber posts, bond strength, push-out test.