Comparative Evaluation of Two Bioceramic-Based Sealers on Root Dentin Strength and Fracture Resistance Under Varying Tooth Conditions: An In Vitro Study

ObjectivesThis study aimed to compare the effects of TotalFill Bioceramic (BC) Sealer (FKG Dentaire, La Chaux-de-Fonds, Switzerland) and TotalFill BC HiFlow Sealer (FKG Dentaire, La Chaux-de-Fonds, Switzerland) on the fracture resistance of roots with and without incomplete simulated vertical root fractures (VRFs). MethodsNinety single-rooted, single-canaled human permanent premolars were standardized to a root length of 15 mm and randomly allocated into three main groups (n=90 in total) and six subgroups (n=15 each) according to the treatment and the presence or absence of a simulated incomplete VRF.Group A (control) received neither canal preparation nor obturation and comprised A1, roots without VRF (negative control), and A2, roots with VRF (positive control).Group B was prepared and obturated with TotalFill BC Sealer using the single-cone technique and comprised B1 (without VRF) and B2 (with VRF).Group C was prepared and obturated with TotalFill BC HiFlow Sealer using warm vertical compaction and comprised C1 (without VRF) and C2 (with VRF).Incomplete VRFs, 7.5 mm long and 0.25 mm wide, were created on the buccal surface starting from the apex.All specimens were loaded vertically in a universal testing machine with a 1.5 mm cylindrical steel rod at 1 mm/min until fracture, and the peak force was recorded in Newtons (N).Data were analyzed using two-way analysis of variance (ANOVA) with treatment and VRF status as independent factors (α=0.05). ResultsThe mean fracture resistance was highest in the negative control group (A1: 853.83±173.63N), followed by the positive control group (A2: 827.30±167.73N), the TotalFill BC groups without and with VRF (B1: 726.35±226.00N; B2: 683.70±198.18N), and the TotalFill BC HiFlow groups without and with VRF (C1: 538.92±198.32N; C2: 531.78±84.48N).Two-way ANOVA revealed no significant main effect of treatment (F(2,54)=2.54;p=0.088) or of incomplete VRF (F(1,54)=0.98;p=0.327) and no significant interaction between them (F(2,54)=0.60;p=0.553). ConclusionWithin the limitations of this in vitro study, neither TotalFill BC Sealer nor TotalFill BC HiFlow Sealer significantly altered root fracture resistance compared with untreated roots, and the presence of a simulated incomplete VRF had no significant effect.Although mean values were lower in the HiFlow groups, these differences were not statistically significant.Larger studies are needed to confirm these findings.