In vitro assessment of sealing performance of C-Root BP as a retrograde root-end filling material: a preliminary study

Achieving a predictable apical seal is essential for the long-term success of endodontic microsurgery. Recently, bioceramic cements have been developed to address the shortcomings of traditional retrograde filling materials. C-Root BP, a strontium-silicate–based bioceramic, has been introduced as a potential alternative. The present study investigated the sealing ability of C-Root BP when used as a retrograde filling material. Fifty extracted human maxillary premolars were prepared, obturated, and divided into experimental, positive control, and negative control groups. In the experimental group, root-end resection and cavity preparation were followed by retrofilling with C-Root BP. Positive control specimens were resected but left unfilled, whereas negative control specimens were completely coated with nail varnish to prevent external leakage. Dye penetration, glucose leakage, and scanning electron microscopy (SEM) were employed to evaluate microleakage and interfacial adaptation. For each leakage assay, specimens were distributed as follows: C-Root BP group, n = 15; positive control, n = 5; negative control, n = 5. Teeth filled with C-Root BP showed markedly reduced dye penetration compared with positive controls, with values approaching those of negative controls ( p < 0.05). SEM observations revealed intimate adaptation of the material to dentin, with few interfacial discontinuities. In the glucose leakage model, leakage in the C-Root BP group remained low throughout 120 days, was significantly lower than the positive control group ( p < 0.001), and did not differ significantly from the negative control group ( p > 0.05). Within the limitations of this in vitro study, C-Root BP exhibited favorable sealing performance as a retrograde root-end filling material, as demonstrated by reduced dye penetration, minimal glucose leakage, and close interfacial adaptation to apical dentin.