Comparison of calcium hydroxide extrusion with syringe versus spiral filler delivery: A pilot study.

This study aimed to evaluate Ca(OH)2 extrusion in relation to delivery technique, apical size and depth of placement. Plastic blocks had j-shaped canals shaped to apical sizes #35 and #45 (n = 32 each). Amounts of calcium hydroxide extrusion was determined relative to apical taper, depth of insertion and whether syringe or spiral filler at 500 rpm was used. Blocks were immersed in pH-sensitive gel and observed for colour change. Extent of extrusion was expressed in mm2 . Extrusion occurred in 48/64 of the samples. At 3 mm from the canal terminus, the device affected the frequency of extrusion, with syringe placement causing extrusion significantly (P < 0.01) more frequently, irrespective of apical size. Extrusion was significantly greater at 2 mm short of the canal terminus (median 27.44 mm2 ) compared to 3 mm (median 19.69 mm2 ). Under in-vitro conditions, a spiral filler at 500 rpm, 3 mm short of the apex, minimised extrusion of Ca(OH)2 from root canals.