Analyse der koronalen Dichtigkeit unter Verwendung verschiedener Wurzelkanalsealer mit verschiedenen Obturationstechniken bei ovalen Wurzelkanälen.

2 English Summary 2.1 Background and Aims Critical to the long-term success of endodontic treatment is a possible coronal tight seal. The aim of the study was to combine several different obturation techniques with different sealing materials to examine the tightness of the coronal portion at oval root canals and to constitute its measurements of the penetration depths. 2.2 Methods 80 in 0.5% aqueous chloramine-T solution stored human teeth (incisors of the lower jaw and molars of the maxilla and mandible) were placed in 8 groups (n = 10) divided. Every group was filled with another filling technique, named non compaction, single-cone, lateral condensation and Thermafil (Dentsply) and the two respective sealers GuttaFlow (Roeko) and Apexit Plus (Ivoclar Vivadent). The teeth were prepared mechanically using the FlexMaster-system and files up to size .04 #45. Subsequently, the entries of the root canals were expanded with sound-powered SonicSys points (Kavo) and after this the oval shape of the root canals was prepared manually with the help of Hedstroem-files up to size .02 #35. After the preparation was then an alternating irrigation with 40% citric acid and 5% sodium hypochlorite performed (2ml), the final irrigation was done with 70% alcohol (1ml). The root canals were obturated with guttapercha points and with one of these two sealers using one of the four mentioned techniques. The teeth were stored for curing the root canal filling for a week at 37 °C and a humidity of 100%. The complete sealing of the teeth with nail polish followed. The dye penetration of the 80 teeth was done (3ml/3min) with 5% methylene blue in a centrifuge at 400 r.p.m. After staining the groups of teeth were embedded in epoxy raisin and serial sections were made of it. The evaluation of the sections was performed using a stereo microscope by three independent examiners. For statistical analysis, the program SPSSwin 11.0 (SPSS Inc., Chicago, IL, USA) was used. 2.3 Results Regarding the various filling techniques which were examined in this study the sealer Apexit Plus combinated with the technique Thermafil resulted in significantly worse in comparison with the other three filling techniques. Single-cone, lateral condensation and non compaction showed no significant differences. Just regarding the sealers GuttaFlow tend to be better than Apexit Plus. The best application result was seen in the use of GuttaFlow in combination with the single-cone technique. Apexit Plus showed the best results in use with lateral condensation. 2.4 Practical conclusion The gutta-percha containing sealer GuttaFlow proved to be very practical to use (cap with canal tip for precise application) and showed in comparison with the calcium hydroxide containing Apexit Plus in three out of four tested techniques to get a better result. Only the lateral condensation Apexit Plus showed a not significantly better value. According to this study the system Thermafil should better be used in conjunction with GuttaFlow. Differences between the easier-to-use masterpoint techniques (single-cone) and the more expensive side-point techniques (lateral condensation and non compaction) hardly exist, so the faster and easier methods are recommended as well as the more complicated techniques.