Evaluation of cinnamon zylanicum (true cinnamon) versus ethylenediaminetetraacetic acid smear layer removal ability: A scanning electron microscope study.

Background: The smear layer has been reported as an irritant and physical barrier on the dentin wall, and its removal is consistent with achieving the goal of biomechanical preparation.

Aim: The aim of this study was to examine and analyze the smear layer removing the ability of cinnamon zylanicum essential oil, and ethylenediaminetetraacetic acid (EDTA) final rinses.

Materials and methods: Thirty maxillary canines were collected, and after access the cavity, preparation working length was adjusted to 20 mm; root canals were instrumented up to apical size #40/0.04. Canals were rinsed with 5 ml of 2.25% sodium hypochlorite. Teeth were divided randomly into two groups: Group A (20% cinnamon zylanicum essential oil/1 min), and Group B (17% EDTA/1 min). Roots were split into labial and palatal halves and scanned using a scanning electron microscope and photomicrographs were processed using Image J software.

Statistical analysis: one-way analysis of variance and Tukey post hoc test were used for intragroup comparison. The independent t-test was used for intergroup comparison.

Results: group (B) showed a higher percentage of open dentinal tubules with an average of 7.97% ± 2.35% and Group (A) showed a low mean percentage of open dentinal tubules with an average of 5.11% ± 2.65%). For both groups, the difference between coronal and middle thirds was not statistically significant, however, there was a significant difference between both thirds and the apical third (P < 0.001).

Conclusion: 20% CEO final rinse has a smear layer removal potential lower than 17% EDTA.