Evaluation of the effects of different techniques used for the removal of different post systems: an in vitro study

The aim of this study was to compare the effects of post material, post removal method, and irrigation activation technique on post removal time, temperature generation, and dentinal tubule penetration following removal of fiber and polyetheretherketone (PEEK) posts. Forty extracted mandibular premolars were restored with either fiber or PEEK posts and allocated according to post removal method (ultrasonic and drill) and irrigation activation technique (Passive Ultrasonic Irrigation (PUI) and Shock Wave–Enhanced Emission Photoacoustic Streaming (SWEEPS)). Post removal time and root surface temperature were recorded during post retrieval. Dentinal tubule penetration was evaluated using confocal laser scanning microscopy. A 2 × 2 × 2 factorial design was analyzed using Generalized Estimating Equations (GEE) for dentinal tubule penetration and two-way ANOVA or robust ANOVA for removal time and temperature-related outcomes. Post removal time was significantly shorter in the drill group than in the ultrasonic group (median: 335 s (245–480) vs. 446.5 s (320–642), n = 20 teeth per group, p = 0.004). The post removal method also significantly affected temperature-related outcomes, with higher overall mean temperatures observed in the ultrasonic group than in the drill group (median: 35.05 °C (32.30–38.28) vs. 28.76 °C (24.10–35.93), n = 20 teeth per group, p < 0.001). Dentinal tubule penetration was significantly greater with PUI than with SWEEPS, with estimated marginal means of 0.739 mm (95% CI: 0.654–0.825) and 0.537 mm (95% CI: 0.449–0.625), respectively (mean difference: 0.202 mm, 95% CI: 0.080–0.325; Bonferroni-adjusted p = 0.001). Post material had no significant effect on post removal time ( p = 0.164) or dentinal tubule penetration ( p = 0.112), although significant effects were observed for selected temperature parameters. Drill removal was associated with shorter removal times and lower temperature increases than ultrasonic removal. PUI resulted in greater dentinal tubule penetration than SWEEPS. Based on the evaluated parameters, PEEK posts demonstrated removal performance comparable to that of fiber posts.