Evaluation of dentin penetration of three different endodontic sealers in the presence and absence of the smear layer

Introduction: A sealer’s ability to effectively and stably penetrate the dentinal tubules is an essential factor for selecting an effective root canal obturation material. Evaluation of the sealers’ penetration into the dentinal tubules provides valuable data in the endodontic treatment outcome. Aim: To compare the dentin penetration of AH Plus, Endoseal MTA, and Syntex endodontic sealers in the presence and absence of the smear layer. Materials and methods: Thirty single-rooted teeth were selected in the present in vitro study and randomly assigned to three experimental groups (n=10). Half of the samples were prepared by removing the smear layer in each group, and the remaining samples were prepared without removing the smear layer. Root canal preparation was carried out with the Perfect Rotary system up to file T3. The root canals were obturated with gutta-percha and AH Plus, Endoseal MTA, or Syntex endodontic sealers. The samples were incubated at 100% relative humidity at 37°C for one week. Each root was sectioned at 2-, 5-, and 8-mm distances from the apex, and sealer penetration depth at each section was determined under a scanning electron microscope (SEM). ANOVA was used to compare penetration depths. Results: There were significant differences in sealer penetration between the samples with and without smear layer removal in each group. The maximum and minimum sealer penetration was at the coronal and apical sections, respectively. The maximum sealer pe-netration depths in descending order were observed with AH Plus, Syntex, and Endoseal MTA sealers (p<0.05). Conclusions: Elimination of smear layer increased three sealers’ dentin penetration depth, with the deepest penetration for the AH Plus sealer in the coronal section without the smear layer.