Apical seal comparison after post space preparation using two different obturation techniques

Achieving apical seal in root canal therapy by Gutta-percha and sealer is an important factor in successful endodontic therapy. The purpose of this study was to investigate the effectiveness of post space preparation on apical seal of canals filled with two different obturation methods. A total of 56 maxillary molar teeth with normal roots were randomly selected in this experimental study. The palatal roots of all specimens were cut at CEJ in order to get the tooth length of 13 mm. The roots were then prepared by FlexMaster rotary system, using crown-down technique. All specimens were divided into four groups. Twenty four specimens in the first group were filled with tapered Gutta-percha 6% and 2SEAL sealer. Another 24 specimens in the second group were filled with lateral condensation technique and 2SEAL sealer. The third group (as positive control) was composed of four specimens; obturated without sealer and four specimens in the fourth group (as negative control) were covered with two layers of nail polish. All specimens were placed in Incubator with 100% humidity and the temperature of 37○C for 72 hours. The post space of 5 mm in length was then prepared by Gates Glidden number III in the first and second groups. Dye penetration technique was used to evaluate the apical seal quality. The groups were compared for differences in the amount of dye leakage using stereomicroscope. Student-T and Kolmogrov-Smirnov tests were used for statistical analysis. The highest leakage was observed in the first group (single cone with Gutta-percha 6%), and the lowest leakage was seen in the second group (Lateral condensation technique with standard Gutta-percha) (P 0.05). Based on these findings, the lateral condensation technique has better apical seal after post space preparation than single cone technique.