Apical Leakage of Different Gutta-Percha Techniques: Thermafil, Js Quick-Fill, Soft Core, Microseal, System B and Lateral Condensation with a Computerized Fluid Filtration Meter Nimet Gençoğlua, Hasan Oruçoğlub, Dilek Helvacıoğluc AbstrAct Objectives: To investigate apical leakage of roots filled with 6 different gutta-percha techniques; Thermafil, JS Quick-Fill, Soft Core, Microseal, System B and lateral condensation using a new comput- erized filtration meter. Materials and Methods: 60 extracted single rooted teeth were used. Coronal part of each tooth was removed and the root canals were prepared with step-back technique. The roots were randomly divided into six groups of 10 teeth, filled by one of the obturation technique and Kerr sealer. The teeth were kept in 100% humidity for 2 years. After this period, apical parts of roots (10±0.05 mm) were attached to computerized fluid filtration meter. Apical leakage quantity was determined as µl.cmH2O-1.min-1. Results: Statistical analysis indicated that Thermafil, Soft Core, Quick-Fill and System B techniques showed lower leakage than Microseal and lateral condensation (P<.05). However, statistically no differ- ence was found among the core techniques and no difference was found between microseal and lateral condensation techniques (P>.05). Conclusions: Thermafil, Soft Core,Quick-Fill and System B techniques showed lower leakage than Microseal and lateral condensation. In addition, this new computerized fluid filtration meter allowed quantitative measurement of leakage easily. (Eur J Dent 2007;2:97-103) Key Words: Fluid filtration; JS Quick-Fill; Microseal; System B; Thermafil; Lateral condensation. IntroducIno Complete obturation of the root canal system with an inert filling material and creation of a her- metic, apical seal have been proposed as goals for a Professor, Department of Endodontics,University of Marmara, Faculty of Dentistry, Istanbul, Turkey. b Assistant Professor, Department of Endodontics, University of Selcuk, Faculty of Dentistry, Konya, Turkey. c Research Assistant, Department of Endodontics, University of Marmara, Faculty of Dentistry, Istanbul, Turkey. Corresponding author: Dr. Nimet GENCOGLU Marmara University, Faculty of Dentistry, Dept. of Endodontics Buyuk Ciftlik Sok.No:6, Nisantasi, Istanbul, Turkey. Fax: +90 212 246 52 47, E-mail: ngencoglu@hotmail.com April 2007 - Vol.1 endodontic treatment.1 Since the most common cause of endodontic failure has been attributed to incomplete obturation, many different obturation techniques have been developed in order to in- crease the success of root canal treatment. Gutta- percha has been material of choice for obturation since 1867. Lateral condensation has proven to be a very popular gutta-percha technique. However, its ability to conform to the internal surface of the root canal has been questioned. Brayton et al2 re- ported voids, spreader tracts, incomplete fusion of the gutta-percha cones and lack of surface adap- tation. Also, this technique relies on sealer to fill accessory canals. Eguchi et al3 reported that lat- eral condensation results in excessive amounts of 97 European Journal of Dentistry