Response to ‘Apical microleakage evaluation of system B and cold lateral compaction’

Dear Editor, This letter is in reference to the study by Farea, Masudi and Wan Bakar (1). In this study, the authors have used single rooted teeth with single canal to evaluate the apical leakage of teeth obturated using system B and cold lateral compaction technique. Intact single rooted teeth with single canal used for in vitro studies are usually premolars which are extracted for orthodontic reasons. It is common to find oval shaped canals in these teeth (2). The oval shape of these canals is shown to make shaping and cleaning difficult. It may be difficult to instrument the entire wall of oval canals using rotary endodontic instruments. The use of rotary nickel-titanium instruments in an oval canal tend to prepare a central circular bulge, with uninstrumented extensions buccally and lingually (3). These uninstrumented recesses that may remain after the preparation of these oval canals with rotary files should be obturated completely with gutta-percha and sealer to achieve a fluid tight seal (4). Study by Wu, Kast’áková and Wesselink (5) concluded that vertical compaction of warm gutta-percha achieves a better quality of obturation than cold lateral compaction of gutta-percha cones in oval canals. The reason for increase in leakage seen with cold lateral compaction might be due to the inadequate filling of the uninstrumented recesses left in oval canals (4). Manuel S. Thomas Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Mangalore, Manipal University, Mangalore, Karnataka, India