Obturation artifizieller Seitenkanäle nach vier verschiedenen Sealerplacementtechniken, Eine In-vitro Studie

2 Summary 2.1 Aim The reason for a inflammation of the dental pulp and the surrounding periapical tissue is always a bacterial infection. Microorganisms remain within dental tubules, accessory foramina, isthmuses and lateral canals. It is currently not possible to completely disinfect all the irregularities and lateral canals, the aim of the endodontic therapy is, to the chemo-mechanical protocol, to seal the complex root canal system and to prevent a reinfection. The aim of this in vitro study was to compare four sealer placement techniques in sealer penetration depth, homogeneity and complete filling. 2.2 Material and Methods The crowns of 60 human, single rooted teeth with straight canals were cut of at the enamel-cemental junction. The preparation was performed with FlexMaster (VDW, Munich, Germany) up to a size ISO 70. Final preperation was accomplished with the Mity Roto file (Loser & Co, Leverkusen, Germany) up to a size of ISO 80. Afterwards the roots were split longitudinally. A groove of 6 mm length and 2 mm deep was cut in one half. In the other half, 4 holes were prepared 2 mm deep and 2 mm, 4 mm, 6 mm and 8 mm from the apex. These prepared roots were put together and embedded into polyurethane blocks (Biresin, Sika N.V, Utrecht, Netherlands). The samples were divided into 4 groups with each 15 teeth in accordance with the placement technique: group 1: guttapercha point, group 2: paperpoint, group 3: sonic activation with ROEKO CanalBrush (Coltène/Whaledent AG, Altstätten, Switzerland) and group 4: ultrasonic activation with (EMS 600) and an inserted Spreader. The obturation was performed with one of the placement-techniques and a well fitted master cone of gutta-percha using a single-cone technique. The sealer that was used for this study was AH Plus (Dentsply DeTrey, Konstanz, Germany). Following the settingtime of the sealer of 48 hours digital radiogaphs (Digora, Soredex, Helsinki, Finland) were made. The images were analysed according to penetration depth, homogeneity and complete filling of the iatrogenic canals. 2.3 Results The sonic and ultrasonic groups were significantly more effective in terms of penetration depth, homogeneity, and complete filling of the artificial lateral canals. The ultrasonic group performed best. 2.4 Conclusion The evaluation of this ex vivo study showed that both, sonic and ultrasonic activation of sealer leads to a greater penetration depth, increased homogeneity and a more complete filling of simulated lateral canals and hollows.