Extrusionsresistenz simulierter Wurzelkanalfüllungen mit TotalFill BC Sealer in Abhängigkeit verschiedener endodontischer Spüllösungen – eine In-vitro-Studie

Introduction: The primary goal of root canal treatment is the elimination or at least a large reduction of microorganisms from the infected root canal system. This can be achieved by the chemomechanical preparation and subsequent complete obturation of the root canal system. In order to create a sufficient obturation of the root canal system the bond strength of the sealer to both the root canal dentin and the core material, usually guttapercha, plays a decisive role to achieve a long-term and stable connection of the root canal filling to the tooth. The aim of the present study was to analyze the extrusion force of the TotalFill BC Sealer depending on different endodontic irrigating solutions by means of a pull-out testing procedure. Material and Method: To carry out the present study, 60 extracted human teeth with a straight root canal and a round channel cross-section were selected. These were decapitated, the root canal anatomy was checked by radiographs, the glide path was prepared and instrumentation was established to a working length of 8 mm. After rotary preparation of the root canal using BioRaCe files up to .02/#60, repeated irrigation with 1 ml of aqua dest. after each change of file, the 60 teeth were divided into 6 groups (n=10). The final irrigation (5 ml) of each tooth in the 6 experimental groups was carried out with one of the endodontic irrigating solutions (aqua dest., CHX, alcohol, NaOCl, citric acid and EDTA). After drying the root canals with paper points, the root canals were obturated with the TotalFill BC Sealer and spreaders and the obturation was controlled by x-rays. After 14 days, the pull-out tests using a Zwick universal testing machine 1120 followed and subsequent to it the statistical evaluation (SPSS 23.0). Furthermore, the spreaders were analyzed fractographically with respect to their fracture mode. Results: As part of the statistical evaluation, citric acid showed significantly lower pullout values compared to all other irrigating solutions. Aqua dest., alcohol and NaOCl had significantly higher pullout values than EDTA. However, irrigation with EDTA resulted in significantly higher bond strength values compared with citric acid. Conclusion: The results showed that especially NaOCl is suitable as an irrigating solution, as the rinsing with this solution resulted in the highest bond strength values in this study. Thus, NaOCl as the standard endodontic irrigating solution can be recommended without restrictions with regard to the bond strength of TotalFill BC Sealer to root canal dentin. CHX, aqua dest., and alcohol showed lower bond strength values, but not significantly lower values than after rinsing with NaOCl. Thus, CHX, aqua dest., and alcohol are also suitable as irrigating solutions. Citric acid and EDTA are rather unsuitable due to their negative effect in terms of bond strength.