Apical Mikroleakage of Four Different Obturation Techniques

Objectives: The aim of the present study was determine the apical microleakage after root canal filling with four different gutta-percha techniques (lateral condensation, single cone technique, vertical condensation (Endo Twinn) and thermoplasticized condensation technique (Thermafil)) in an in vitro investigation. Methods: Thirty-six extracted single rooted incisors stored in saline were used. Each tooth was endodontically prepared using the Hero 642 system to a maximum size of 40 under constant sodium hypochloride and chlorhexidine irrigation. The root length was determined by insertion of a size 10 file into the canal until it appeared at the apex. The working length was recorded 1 mm shorter. The teeth were randomly assigned to four experimental groups of nine each: group A: lateral condensation, group B: single cone technique, group C: vertical condensation (Endo Twinn), group D: thermoplasticized condensation (Thermafil). In each group AH Plus served as sealer. After root canal filling the teeth were coated with nail varnish, leaving the apical foramen exposed and stored in 5% methylene blue solution for six days. After that all teeth were bisected along their long axis. Linear dye penetration (apical – coronal) was measured using a light microscope. Statistical analysis was performed using SPSS 10.0. Results: Following mean values of linear dye penetration were recorded (in µm, with standard deviation): Group A: 212.22 (+/- 76.20); group B: 155.83 (+/- 60.72); group C: 81.67 (+/- 44.07) and group D: 107.22 (+/- 45.18). Statistical analysis revealed a significant higher penetration depth in group A, no significant differences between group C and D could be detected (p<0.05, Tukeys test). Conclusions: Within the limitations of an in vitro investigation it can be concluded that use of Thermafil and vertical condensation might decrease the risk of apical leakage.