Ein Vergleich unterschiedlicher Methoden der Applikation von Wurzelkanalsealern - Eine In-Vitro-Studie -

Abstract

Aim of the study: The aim of this study was to compare three methods of endodontic sealer placement in straight root canals with two different preparation sizes (ISO 35 and 45). The distribution of the sealer on the walls in the different thirds of the root canals should be examined separately with a focus on the apical third, where a standardized groove was prepared and filled with the sealer. The null-hypothesis was that all three techniques were equal in their ability to place sealer onto the root canal wall in all three thirds of the root canal and into apical lateral grooves in root canals prepared to two different sizes of .02/35 or .02/45. <br />Material and methods: One hundred and twenty extracted human anterior teeth or single rooted premolars with a round canal cross-section were randomly divided in two groups. With Flex Master-NiTi-files the root canals were prepared to the sizes .02/35 or .02/45, respectively, and split longitudinally. In one root canal half of each tooth a standardized groove was prepared in the apical third. The canal halves were reassembled and each of the two groups was randomly divided into three sub-groups with 20 teeth for each method of sealer placement. With three different methods the Sealer AH Plus was placed in the root canals (Lentulo, ultrasonically activated file and CanalBrush). After storage in an incubator the canal halves were separated again for the analysis using a score-system. For this purpose, a digital photograph with 20x magnification of each canal wall and an image in 40x magnification of the apical groove were using a reflected light microscope with a digital camera. All images were scored independently by two calibrated observers. The statistical analysis was performed with a nonparametric repeated-measures-ANOVA-test (p<0.05).<br />Results: The study revealed significant differences between the three methods of sealer placement and the two different preparation sizes as well as in the observation of the standardized grooves and the canal walls. The CanalBrush for both preparation sizes and all canal sections and the groove showed the best results and performed significantly better than the other techniques, except one case with the same results for the Lentulo. The ultrasonically activated file with one exception presented the worst results. With regard to the placement of the sealer into the grooves the CanalBrush again continuously presented better results than the other techniques or in a few cases the same results as the Lentulo, respectively. The ultrasonically activated file showed significantly worse sealer distribution into the grooves. <br />Conclusion: The CanalBrush especially in the apical third of root canals with a small preparation diameter seems to be the best suited method for distribution of the endodontic sealer. The CanalBrush was able to distribute the sealer also into the difficult accessible apical grooves. However, the risk of loss of the CanalBrush-bristles in the root canal has to be considered. The null hypothesis had to be rejected.