Evaluation of the Penetration Depth of Four Different Root Canal Sealers into Dentinal Tubules: A Scanning Electron Microscopic Study

Aim This study was designed to establish the average depth of penetration of four different root canal sealers into the dentinal tubules at the cervical, middle, and apical third levels. Methodology Forty-eight mandibular premolars were decoronated, and cleaning and shaping were done in a crown-down manner using ProTaper Gold (Densply Maillefer, Ballaigues, Switzerland) rotary instruments. To simulate smear layer removal in a clinical setting, all canals were then irrigated with 3 ml of 17% ethylenediaminetetraacetic acid (EDTA), i.e., SmearClear (Sybron Endo, Glendora, CA, USA) for one minute, followed by 3 ml of 3% sodium hypochlorite. Canal irrigation was performed with 5 ml of saline to get rid of excess irrigating solution. All the samples were randomised into four groups based on the sealer by a person not related to the study to ensure anonymity, as follows: Group A: Zinc oxide eugenol sealer (ZOE); Group B: AH Plus sealer (Densply Maillefer); Group C: Apexit Plus sealer (Ivoclaar vivadent, Gurugram, India); Group D: mineral trioxide aggregate (MTA) Fillapex sealer (Angelus, Torrance, CA, USA). Obturation of the samples was done using the lateral compaction, and samples were then sectioned in the bucco-lingual mode using a disc under copious irrigation using distilled water. Samples were dehydrated and gold sputtered for scanning electron microscopy (SEM) evaluation. Data was pooled and interpreted using the Mann-Whitney U test and Kruskal-Wallis test. Results Analysis showed a statistically significant difference with a p-value of