Assessment of Physical Properties, Obturation Quality, and Cytocompatibility/Osteogenic Potential of KP-Root SP: A New Calcium Silicate-based Bio-ceramic Sealer.

Introduction: The study aims to evaluate the physical properties, obturation quality, biocompatibility, and osteogenic induction characteristics of KP-Root SP with iRoot SP.

Methods: The evaluation of flow, film thickness, radiopacity, and solubility was conducted according to ISO 6876 Dentistry-Root Canal Sealing Materials. Forty isolated premolars, after preparation, were numbered and randomly assigned into 2 groups, and root-filled using size-fitted gutta-percha master cones along with KP-Root SP or iRoot SP sealers. Micro computed tomography (Micro-CT) scans were performed pre- and postobturation, and reconstructed images were analyzed to determine the volumetric percentage of the filling materials. After setting, the sealers' microstructure and composition were analyzed using light microscopy, scanning electron microscopy, and energy dispersive spectroscopy. The release of silicon, calcium, and strontium ions were identified using inductively coupled plasma mass spectrometry. Cell proliferation, inflammatory cytokine production (interleukin-4 (IL-4), interleukin-6 (IL-6), and interleukin-8 (IL-8)), and osteogenic potential were examined in human periodontal ligament cells (hPDL cells) exposed to KP-Root SP or iRoot SP.

Results: Both KP-Root SP and iRoot SP comply with the ISO 6876:2012 standard regarding flow, film thickness, radiopacity, and solubility. The 2 groups demonstrated 84%-95% canal space occupancy with root filling material. No notable differences were observed in the entire root canal, as well as in the apical and middle thirds. The KP-Root SP group contained a greater average volume of filling material in the coronal third than the iRoot SP group. Microscopic images and scanning electron microscopy analyses revealed that both materials exhibited no obvious gaps with dentin or gutta-percha, indicating good sealing properties. Both iRoot SP and KP-Root SP contain similar core elements in varying proportions. Additionally, KP-Root SP includes strontium. iRoot SP and KP-Root SP extracts at a concentration of 20 mg/mL have no cytotoxic effects on hPDL cells at both 24 and 48 hours. While iRoot SP and KP-Root SP promoted the release of IL-4 to induce an anti-inflammatory response, they also triggered increases in IL-6 and IL-8, reflecting a proinflammatory response. Both iRoot SP and KP-Root SP enhanced the osteogenic potential of hPDL cells.

Conclusions: The results demonstrate that KP-Root SP and iRoot SP show no significant differences in terms of physical properties, obturation quality, cytocompatibility, and osteogenic potential.