Airborne-particle Abrasion Increases Surface Roughness of Fiber-reinforced Posts

Objectives: Debonding is the most common complication of fiber-reinforced posts. Airborne-particle abrasion has been suggested to increase the adhesion of resin cements to the surface of fiber posts. However, it is unknown which is the most favorable abrasion protocol. The aim of this study was to compare the surface roughness of three fiber post systems following four airborne-particle abrasion protocols.
Methods: A total 150 posts from 3 manufacturers (A:GT Fiber Post, Dentsply; B:GC Fiber Post, GC America; C:ICELight, Danville) were subjected to the following treatments: 0: no treatment (control), 1: no airborne-particle abrasion – ethanol cleaned, 2: airborne-particle abrasion for 2 seconds/mm² – ethanol cleaned, 3: airborne-particle abrasion for 5 seconds/mm² – ethanol cleaned, and 4: airborne-particle abrasion for 10 seconds/ mm² – ethanol cleaned. Airborne-particle abrasion was performed with 50μm Aluminum Oxide. Each post was observed under a 3D laser microscope (Lext; Olympus). Average roughness in 3-D (S_a) was recorded using a 20X objective lens.
Results: Data were analyzed with 2-way ANOVA followed by Tukey’s B test (α=.05)
The mean (SD) S_a roughness (μm) for each of the 15 groups was: GT Fiber Post - 0: 2.21(0.23), 1: 2.51(0.29), 2: 3.47(0.51), 3: 3.92(0.51), 4: 4.10(0.63), GC Fiber Post - 0: 2.25(0.14), 1: 2.71(0.08), 2: 3.32(0.32), 3: 4.24(0.82), 4: 3.68(0.29), ICELight - 0: 2.52(0.18), 1: 2.81(0.19), 2: 3.73(0.25), 3: 3.60(0.25), 4: 3.66(0.41). The interaction between post brands and treatment protocols was statistically significant (P=.000). A statistically significant difference was found between the treatment protocols (P=.000), no significant difference was found between the different post brands (P=.937). Post-hoc test showed lowest roughness for A0, B0, A1, C0, B1 and highest roughness for C2, A3, A4, B3.
Conclusions: Post brand did not affect surface roughness. Air-particle abrasion time significantly affected surface roughness in all post systems. Optimum roughness was observed when post surfaces were treated with 2- 5seconds/mm² of air-particle abrasion.