Effect of Different Airborne-Particle Abrasion Strategies on Dentin Bond Strength: An In Vitro Study

To assess the influence of dentin airborne-particle abrasion techniques on the microtensile bond strength, using two adhesive strategies (self-etch and etch&rinse).

Twenty molars were assigned to two groups (n = 10) according to the bonding system (Clearfil SE Bond or Optibond FL), divided into four parts and submitted to different surface treatments: no pretreatment (control), airborne-particle abrasion with aluminum oxide without irrigation (Al₂O₃), airborne-particle abrasion with aluminum oxide with irrigation (Al₂O₃/Aquasol), and airborne-particle abrasion with bioactive glass 45S5 (BG45S5). Specimens underwent microtensile bond strength (μTBS) testing and scanning electron microscopy (SEM) analysis. Statistical analysis employed a linear mixed regression model, with a 5% significance level.

Statistically significant differences were found for both adhesive strategy (p < 0.001) and pretreatment (p < 0.001). Al₂O₃/Aquasol and Al₂O₃ exhibit statistically significant differences compared to the control (p < 0.001 and p = 0.006, respectively), while BG45S5 did not differ significantly (p = 0.080). SEM images reveal a smear layer with distinct density across groups, and diminished compactation whenever irrigation was used.

Aluminum oxide with simultaneous irrigation resulted in the highest bond strength values, while without irrigation bond strength outcomes depend on the adhesive strategy. Bioactive glass did not interfere with bonding performance.

Aluminum oxide airborne-particle abrasion with concomitant irrigation presents the preferable surface pretreatment strategy when bonding to sound dentin.