ORIGINAL RESEARCH Fluid-transport evaluation of lateral condensation, ProTaper gutta-percha and warm vertical condensation obturation techniques Fani Mahera, DDS; Nikolaos Economides, DDS, MSc, PhD; Christos Gogos, DDS, PhD; and Panagiotis Beltes, DDS, PhD Department of Endodontology, Faculty of Dentistry, Aristotle University, Thessaloniki, Greece Keywords Gutta-percher, ProTaper, sealing ability. Correspondence Dr Christos Gogos, Vamvaka 1, 54631 Thessaloniki, Greece. Email: gogos@dent.auth.gr doi:10.1111/j.1747-4477.2009.00158.x Abstract The purpose of this study was to compare the microleakage of four obturation techniques (lateral condensation, lateral condensation of ProTaper Gutta- percha, single ProTaper Gutta-percha and warm vertical condensation) over a 3-month period. A fluid-transport model was used to measure microleakage. Sixty human-extracted teeth, divided into four groups, were prepared with ProTaper rotary instruments before the root canals were filled by one of the four examined techniques. All groups were obturated using Sultan as a root canal sealer. Microleakage was measured 7 days, 1 month and 3 months after the procedures. There were no statistically significant differences between the four groups at any of examination points (P > 0.05). The leakage was increased in all obturation techniques over the 3-month period. Introduction Obturation of the root canal space after cleaning and shaping is critical for successful root canal treatment. The various proposed methods for obturation of the radicular space can be divided into two basic groups: cold lateral condensation and warm vertical condensation (1,2). Lateral condensation of gutta-percha filling material is the most commonly taught and practiced filling tech- nique, and is the standard procedure against which all others are evaluated (3). Although many variations of the technique have been proposed in terms of master cone design, spreader design, application and accessory cone selection, there is no clear consensus of which is ideal (4). Lateral condensation is a safe and cost-effective tech- nique, but it is time-consuming (5) and lacks homogene- ity (6) and adaptation to the canal walls (7). Moreover, a common criticism levelled at the technique is that it may induce vertical root fractures (8). Warm vertical condensation was first introduced by Schilder in 1967 (1). The continuous wave of condensa- tion technique (9) with the system B heat source (Ana- lytic Sybron Dental Specialties, Orange, CA, USA) was introduced to simplify vertical condensation. Recently, a new system (Elements Obturation Unit, SybronEndo, Orange, CA, USA) that combines the technology of system B and a motor-driven extruder handpiece of thermoplasticised gutta-percha has been marketed. Warm vertical condensation improves the homogeneity and adaptation of gutta-percha to the dentin walls (1). However, the procedure may result in extrusion of the gutta-percha filling material into the periapical tissues (10), and concerns have been raised with regard to thermal damage to the periodontal ligament during thermal condensation (11). The introduction of nickel- titanium (Ni-Ti) rotary instrumentation has altered root canal treatment by reducing preparation time, mini- mising procedural errors associated with root canal instrumentation and producing a predictably centred preparation, even in curved canals (12,13). Gutta-percha cones are now produced that match the taper of canals prepared with Ni-Ti rotary systems. Different leakage tests are performed to comparatively evaluate sealing ability. Examples of such methods include dye penetration tests, electrochemical leakage tests, radioactive isotope studies, bacterial penetration tests and the fluid-transport model. The fluid transporta- tion model is a non-destructive method of leakage Aust Endod J 2009; 35: 169–173 169 © 2009 The Authors Journal compilation © 2009 Australian Society of Endodontology