Comparison of two vertical condensation obturation techniques: Touch 'n Heat modified and System B

Aim The aims of this study were firstly to compare the area of canal occupi ed by gutta-percha, sealer or voids using the System B heating device with that obtained by a modified vertical condensation technique using the Touch 'n Heat; and secondly to compare the temperature changes at the root canal wall and external root surface during obturation with the above techniques , Methodology Forty-five resin blocks, each with a standardized, simulated, p repared main root canal and five lateral canals, were assigned to three equ al experimental groups. The canals were obturated using either the System B technique at two different temperature settings, or vertical condensation with a Touch 'n Heat instrument as the heat source. A heat transfer model w as used to simultaneously record internal and external root surface tempera ture elevations during obturation by the three techniques, Data were analys ed using unpaired Student's t-test and Mann-Whitney U-test. Results Both obturation techniques produced root fillings consisting of ove r 90% gutta-percha at most levels, although the percentages of sealer and v oids 2-3 mm from the working length following System B obturation were high er than those found following modified vertical condensation, Modified vert ical condensation resulted in more gutta-percha in lateral canals. Obturati on was accomplished more quickly using the System B, and temperature elevat ions produced during obturation with the System B were significantly less ( P < 0.001) than with vertical condensation. An elevation of external root s urface temperature by more than 10 degrees C occurred during vertical conde nsation. Conclusions The results suggest that the System B may produce an acceptable obturation and that the use of a Touch 'n Heat source during vertical cond ensation may result in damage to the periodontium.