In Vitro Evaluation Of The Apical Sealing Ability Of Iroot SP Sealer Filling Using Single-Cone Technique With Ultrasonic Activation

Objective:The purpose of this study was to investigate the apical sealing ability of a recently developed premixed root canal sealer(iRoot SP)with a single gutta-percha(GP)cone technique compared with a resin-based sealer(AH plus)with warm vertical compaction.We also evaluate the effectiveness of GP cone-mediated ultrasonic activation on the filling quality of iRoot SP.The findings we obtained will provide a basis for clinical.Materials:75 intact mandibular first molars extracted clinically were selected.After cutting the pulp and dredging the root canal as usual,working length was measured.Tooth were prepared by S3 rotary system to an root canal preparation of file size 3S,and then randomly divided into 4 groups according to the different filling methods: Group A: 15 root canals were filled by i Root SP root canal sealer plus single root cone obturation technique,Group B: 15 root canals were filled by AH plus root canal sealer plus continuous wave compaction technique,Group C: 15 root canals were filled by iRoot SP root canal sealer plus single-cone with GP cone-mediated ultrasonic activation,Group D(positive control group): 15 root canals were only filled with gutta-percha by continuous wave compaction technique.Group E(negative control group): 5 root root canals were filled by iRoot SP root canal sealer plus single root cone obturation technique,5 root canals were filled by AH plus root canal sealer plus continuous wave compaction technique,the surface of root canals were required to apply nail varnish to seal fissures.X-ray examination was used after operation to make sure that all sample root canals were tightly filled.Two coats of nail varnish were applied to the external surfaces of all teeth excluding the last 2 mm of the apical portion,except for the Group E.Establish bacterial microleakage model: the coronal portions of the root canals of 10 teeth in all groups were placed in contact with Enterococcus faecalis in BHI broth,the tubing was then suspended over the BHI broth so that approximately 2 mm of the apex of the tooth was immersed in it.All of the specimens were examined every day during the test period(90 days).Statistical analysis using Wilcoxon test(?=0.05)to determine whether the differences between the three methods were statistically significant.Results:During the period,the percentage of bacterial microleakage in iRoot SP with single-cone method,AH Plus with continuous wave compaction technique,iRoot SP plus single cone with GP cone-mediated ultrasonic activation respectively were 50%(5/10)?50%(5/10)?40%(4/10);the days of microleakage were 9-84d?6-80d?10-87 d,there were no differences between three groups.Conclusions:The apical sealing ability of iRoot SP root canal sealer with singl-cone obturation technique was similar to that of AH plus root canal sealer with continuous wave obturation technique.The adjunctive GP cone-mediated ultrasonic activation can improve the root canal filling quality.