Comparative study of retreatment of Thermafil and lateral condensation endodontic fillings

Abstract

The aim of the present study was to evaluate the possibility of retreating teeth obturated with: (i) Thermafil with plastic carrier, (ii) Thermafil with metallic carrier and (iii) laterally condensed gutta-percha. The following aspects were analysed: removal of obturation, time required for removal, remaining filling material and apical extrusion during reinstrumentation. Thirty human teeth with a single canal were instrumented up to a size 45 K-type file, divided into three groups of 10 teeth each and obturated with Thermafil with plastic carrier (group 1), Thermafil with metallic carrier (group 2), and laterally condensed gutta-percha (group 3) with AH26 as the sealer. Reinstrumentation was performed manually after 30 days storage using Hedstroem files and xylene as a solvent. The average time needed to remove the obturation was 12 min 1 s for group 1, 14 min 36 s for group 2 and 11 min 26 s for group 3. Although no statistically significant differences were observed between groups 1 and 2, and 1 and 3 (P > 0.05), the differences between groups 2 and 3 were significant (P < 0.05). The amount of remaining filling material was significantly higher in group 2 when compared with groups 1 and 2 (P < 0.01). Although the lowest incidence of apical extrusion during reinstrumentation was found in group 3, the differences among groups were not statistically significant.

Efficiency of the 0.04 taper ProFile during the re-treatment of gutta-percha-filled root canals

“…In the present study, the mean time required to remove the Thermafil plastic carriers was less than the half mean time reported in the study of Frajlich et al . (1998).…”

Efficacy of the ProTaper retreatment system in removing Thermafil, GuttaCore or vertically compacted gutta‐percha from curved root canals assessed by micro‐CT

“…In addition, no significant differences of remaining filling material were observed after removal of Thermafil and laterally compacted gutta‐percha (Frajlich et al . ). A two‐dimensional evaluation of split specimens also demonstrated similar amounts of filling remnants after retreatment of Thermafil, GuttaCore and thermoplasticized gutta‐percha (Nevares et al .…”

“…However, in retreatment cases, carrier‐based systems may be more time‐consuming or more difficult to remove completely (Frajlich et al . , Baratto et al . ).…”

Effects of root canal preparation, various filling techniques and retreatment after filling on vertical root fracture and crack formation

“…Frajlich et al. showed that the time required for the removal of gutta‐percha with the warm vertical condensation technique was greater than with the lateral condensation technique. Thus, the number of cracks on root canal wall could be different after the retreatment of different root canal filling techniques.…”