Comparison of spreader penetration during lateral compaction of .04 and .02 tapered gutta-percha.

The purpose of this study was to compare the initial penetration depth of fine-fine nickel-titanium (NiTi) and fine-fine stainless-steel (SS) spreaders during lateral compaction of .02 or .04 tapered master gutta-percha cones and to evaluate the effect of increasing canal curvature on penetration depth. Fifty-one root canals were instrumented to a standardized size and grouped by degree of curvature for comparison. Our results showed that NiTi spreaders penetrated to a significantly greater depth than SS spreaders using .02 tapered gutta-percha in canal curvatures greater than 20 degrees and when using .04 tapered gutta-percha regardless of canal curvature. No significant difference occurred between NiTi and SS-spreader penetration using .02 tapered gutta-percha in canal curvatures of 0 to 20 degrees (p > 0.05). Both NiTi and SS spreaders penetrated to a greater depth as canal curvatures increased to greater than 20 degrees (p < 0.05). Both NiTi and SS spreaders penetrated to a shallower depth with .04 tapered gutta-percha compared with .02 tapered gutta-percha (p < 0.0001).