An in Vitro Comparison of Apical Microleakage in Two Obturation Techniques: Lateral Condensation and One-Step

For a successful root canal treatment, canal must be obturated apically, coronally and laterally to prevent microleakage and canal reinfection. Cold lateral condensation is the most popular method of canal obturation; an easy method with a controlled filling. Cold lateral technique disadvantages are presence of void, possible vertical root fracture, and absence of a homogenous and condensed filling. In some techniques like One-step, heat is used to soften gutta-percha for better adaptation to canal walls. The purpose of this study was to compare of the apical microleakage in roots obturated with One-step and lateral condensation techniques.Methods and materials: In this in invitro study ninety extracted human maxillary central incisors, canines, and mandibular premolar (single rooted teeth) were instrumented to a size 40 file and step back flaring was performed to a size 80 file. Apical patency was ensured in all teeth. The teeth were divided into two experimental groups of 40 each and two positive and negative control groups. In the first experimental group, the roots were obturated with lateral condensation gutta-percha technique and AH26 as a sealer. In the second experimental group, the roots were obturated with One-step technique and AH26 according to the instruction of manufacturer. All roots were placed in humidor with 100% humidity and incubated at 37ºc for 3 days to allow the sealer to set. After achieving coronal seal, the roots were coated with two layers of fingernail polish and one layer of stickywax except for the apical 2-3mm and then placed into India ink and incubated at 37ºc for 72h. The roots were removed from the dye, fractured longitudinally and liner dye penetration was measured. The mean apical dye penetration in laterally condensed technique and One –step technique were 3.60±2.03 mm and 4.00±2.23 mm respectively. Dye penetration in negative control group was zero, and in the positive control group dye pentrated through all the canal system. Statistical analysis of the results did not show significant difference between two groups. Although there was no statistical difference in the sealing ability of laterally condensed and One-step techniques, further in vivo and in vitro studies are needed to prove the clinical abilities of One-step technique.