Do fiber tips with different geometric designs affect intracanal medicament removal in laser-activated irrigation of immature permanent teeth?: an in vitro study

This in vitro study aimed to evaluate the effects of fiber tips with different geometric designs on the removal of intracanal medicaments during laser-activated irrigation (LAI) in immature permanent teeth. A total of 110 mandibular premolars were prepared using standardized procedures to simulate immature permanent tooth models. The teeth were randomly assigned to two groups according to the intracanal medicament applied. Calcium hydroxide (CH) and double antibiotic paste (DAP) were removed using standard needle irrigation (SNI) and LAI protocols, namely PIPS and SWEEPS, with two different fiber-tip end designs: flat (F) and radial (R). After irrigation, the specimens were examined under a stereomicroscope and digital images were obtained. The efficacy of medicament removal was quantitatively assessed by calculating the percentage area of residual medicament within the canal space using image analysis software (ImageJ). A significant difference was observed between the CH and DAP groups in terms of residual medicament levels (p < 0.05), with lower residue values in the CH group. Significant differences were also found among the irrigation activation protocols (p < 0.05). SNI showed the lowest removal efficiency, whereas SWEEPS-R resulted in the lowest residual medicament values. Within the limitations of this in vitro study, the SWEEPS-R protocol showed the highest removal efficiency for both CH and DAP, whereas SNI resulted in the greatest amount of residual medicament. CH was removed more effectively than DAP, and none of the tested protocols achieved complete removal. Understanding the influence of fiber-tip geometry on medicament removal may help guide the selection of more effective LAI protocols for regenerative endodontic procedures in immature permanent teeth.