Short-term radiographic changes of extruded NeoSealer Flo in a simulated enlarged-apex model: influence of moisture and periapical support.

Abstract

Objectives: To radiographically evaluate short-term changes in NeoSealer Flo extruded beyond enlarged apical preparations under different moisture and apical-support conditions.

Materials and methods: Thirty-two extracted single-rooted human teeth were randomly allocated to four experimental conditions (n = 8 per group). Teeth were prepared with reciprocating NiTi instruments to size 50/0.05 and filled with a matched gutta-percha cone and a premixed bioceramic sealer. The conditions combined the presence or absence of sponge support around the apex with dry or phosphate-buffered saline PBS-moistened canals. Standardized radiographs were acquired immediately after filling (T0), at 7 days (T1), and at 28 days (T2). Intracanal radiopaque area (Area of the canal, AOC) and apically extruded radiopaque area (Area of Extrusion, AE) were traced within a calibrated 6 × 10-mm region of interest. Separate random-intercept linear mixed models included group, time, and their interaction; pairwise comparisons used Sidak adjustment.

Results: Mean AOC changed by no more than 0.56 mm² within groups. The group-by-time interaction was not significant for AOC (Wald χ²(6) = 5.31, p = 0.505) but was significant for AE (Wald χ²(6) = 21.72, p = 0.001). From T0 to T2, mean AE changed by + 3.38 mm² (Group 1; dry/sponge), + 0.25 mm² (Group 2; moist/sponge), + 1.50 mm² (Group 3; dry/no sponge), and + 0.41 mm² (Group 4; moist/no sponge).

Conclusions: Intracanal radiopaque area remained relatively stable over 28 days, whereas the extruded radiopaque area differed among experimental conditions. The largest mean increase occurred in the dry, sponge-supported group.

Clinical relevance: Local moisture and periapical status may influence the radiopaque area of extruded NeoSealer Flo. However, the radiographic changes do not directly demonstrate material expansion, dissolution, resorption, or biological integration. Apical extrusion should be minimized in clinical practice.