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

By Wilson BL, Baumgartner JC.

Date: 12/2004
Journal: JOE


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.


-N= 51 root canals -coronal half of the crown for each tooth was removed, Access, WL using #10 K-file.

-Standardized canal preparation: crown-down continuous taper instrumentation (Profile .04 taper, sizes 20-40).

-2.6% sodium hypochlorite  irrigation, orifices enlarged with a #5 Gates Glidden.

-Buccolingual and mesiodistal RGs scanned, and images were digitized, the curvatures of canals were measured according to Schneider.

-The apparatus was placed on an analytical scale to measure the force used during spreader placement. (Fig.)

-The apical 5 mm of each gutta-percha cone was coated with ZOE sealer

-Apical force of 1.5 kg ( 0.05 kg), with no rotational force, was applied to place the spreaders.

-FF, 25 mm NiTi, and FF, 25 mm SS finger spreaders were used with size 40/.04 and size 40/.02 GP cones.


-(a) NiTi spreader with size 40/.02 taper master cone

-(b) NiTi spreader with 40/.04 taper master cone

-(c) SS spreader with 40/.02 taper master cone

-(d) SS spreader with 40/.04 taper master cone.

– For each group, the depth of spreader penetration was recorded three times using a new master cone for each measurement and averaged for analysis.

-Canals were then divided by their degree of curvature into two subgroups  0–20 degrees, and > 20 degrees).

Most highlighted Results:

Table and figure

  • The mean depths of spreader penetration= distance from working length

– The depth of penetration for both NiTi and SS spreaders was significantly less when using .04 Vs. .02 master cones.

– The mean difference in depth of spreader penetration between .04 and .02 tapered cones was 2.93 mm for NiTi spreaders and 3.17 mm for SS spreaders.

– Both NiTi and SS spreaders penetrated to a significantly greater depth in canals with curvatures > 20 degrees compared with canals with curvatures of 0-20 degrees using both .02 and .04 tapered master cones