Percentage of canals filled in apical cross sections - an in vitro study of seven obturation techniques.

Aim: To compare the apical density of several obturation techniques when used in palatal roots of extracted maxillary molars.

Methodology: Seventy extracted molars were randomly divided into seven groups with 10 teeth each. The palatal root canals were instrumented to size 60 MAF, coated with Kerr's Pulp Canal Sealer, and obturated using one of seven techniques. The palatal roots were separated from the crowns, decalcified, and sectioned horizontally at 2 and 4 mm from the apex. The cross-sections were photographed through a microscope, the photos were analysed, and the amount of area in the canal that was obturated with gutta-percha was measured. The means for the 20 sections per group were calculated and the means were compared using mixed analysis of variance test.

Results: Simplifill used in accordance with the manufacturer's directions and Thermafil had the greatest mean obturated area, but neither were statistically better than mechanical lateral or warm vertical compaction (WVC; Schilder Technique). Simplifill as recommended and Thermafil were statistically better than cold lateral (P = 0.0210 and 0.0433, respectively), WVC (continuous wave) (P = 0.0006 and 0.0015), and the modified Simplifill group (P = 0.0010 and 0.0012). In addition, mechanical lateral and WVC (Schilder) had statistically more obturated area than WVC (continuous wave) (P = 0.0054 and 0.0073) and modified Simplifill (P = 0.0015 and 0.0016). Cold lateral and WVC (continuous wave) had significantly more obturated area than modified Simplifill (P = 0.0040 and 0.0087).

Conclusions: Simplifill as recommended, Thermafil, mechanical lateral and WVC (Schilder) obturation techniques created more complete obturation using gutta-percha at the 2 and 4 mm levels than cold lateral, WVC (continuous wave), and Simplifill not used as directed.