The effect of two glass ceramic materials bonded with light and dual cure resin cement on the fracture resistance of anterior sectional veneers following cyclic loading: (In-vitro study)

Background: This study quantitatively compared the apical extrusion of debris during the shaping of moderately to severely curved mandibular molar mesio-buccal canals using two rotary systems: ProTaper Next and iRace.Methods: Forty mesial roots from selected human mandibular molars, with inclusion criteria requiring a mesiobuccal canal curvature ranging from 25 to 35 degrees were selected.Then, teeth were mounted and scanned via CBCT to confirm anatomy.The roots were sectioned, and the mesiobuccal canals were instrumented to an apical size 30 using either ProTaper Next (PTN) or iRace (iR) systems (n=20/group) in a torquecontrolled motor.Apically extruded debris were collected into pre-weighed Eppendorf tubes using a Myers-Montgomery apparatus, desiccated, and re-weighed to determine the net debris mass.A one-way ANOVA was employed for statistical analysis, with post hoc comparisons conducted using Tukey's HSD test.A p-value of less than 0.05 was considered statistically significant.Results: While both instrumentation techniques resulted in apical debris extrusion, quantitative analysis demonstrated a statistically significant difference between the groups.A significantly higher mean volume of extruded debris was produced by the iR system in comparison to the ProTaper Next system (p < 0.001). Conclusion:The Protaper Next system decreases the incidence of postoperative pain or flare up after shaping of curved canals than the iRace system.