%0 Journal Article %T In Vitro Effects of External Pressure Changes on the Sealing Ability under Simulated Diving Conditions %A Marcus Stoetzer %A Martin Ruecker %A Andreas Koch %A Dirk Ziebolz %A Horst Kokem¨šller %A Christina Kaempf %A Nils-Claudius Gellrich %A Constantin von See %J ISRN Dentistry %D 2012 %R 10.5402/2012/418609 %X Aim. To measure and validate the permeability of pressure changes in correlation to different root filling techniques. Methods. Eighty extracted single-rooted teeth were randomly assigned to one of eight groups of ten teeth. Following standardized instrumentation and irrigation, root canal fillings were performed using either cold lateral condensation, a warm carrier-based gutta-percha obturation technique, a warm carrier-based Resilon, or warm gutta-percha compaction with the downpack/backfill technique. After insertion of a pressure sensor within the pulp chamber ten teeth of each group then underwent simulated dives with pressure measurement and the other ten a dye penetration test during simulated dives to 5.0 bar. Differences were analyzed statistically ( ) using one-way analysis of variance (ANOVA). Results. When the warm carrier-based gutta-percha obturation technique and vertical gutta-percha obturation techniques were used, there was significant lower intrapulpal pressure to experimental chamber pressure ( ). When cold lateral condensation or carrier-based Resilon as used, pressure was sometimes almost completely equalized. Conclusions. Warm gutta-percha obturation techniques provide a largely pressure-tight seal whereas the Resilon obturation technique and cold lateral condensation appear to be unsuitable to pressure changes. 1. Introduction Root canal fillings must meet a number of requirements. Not only must they be biocompatible and removable, but they must also tightly seal the root canal system. The effectiveness of the seal depends on the anatomy of the root canal system and especially on the shape of the canal and the type of mechanical preparation. It is undisputed that an effective seal can be technically achieved if the root canal is tapered from crown to apex [1]. Different materials and methods can be used to fill and seal a root canal. Differences mainly pertain to how filling materials are processed and whether accessory ramifications can be filled effectively [2]. Cold lateral condensation is still a widely accepted method of root canal obturation, although accessory ramifications can hardly be filled using this technique [3]. Apart from this technique, warm thermoplastic obturation methods in particular have become established in recent years [4]. These techniques use either carrier-based obturation material or simply heated filling material [5]. Many studies are available that have investigated the adaptation of root fillings to the root canal walls and the ability of filling materials to seal the root canal system. For %U http://www.hindawi.com/journals/isrn.dentistry/2012/418609/