Antimicrobial Efficacy of Two Different Calcium Hydroxide Endodontic Dressings on the Eradication of Enterococcus faecalis in Single-Rooted Canals: An In Vitro Study

Introduction: Bacterial pulp infections are considered the most common cause of endodontic treatment failure. Enterococcus faecalis was isolated from most cases of failure of endodontic treatment. Therefore, using the appropriate intra-canal dressing is essential for successful treatment. The improved formula used in calcium hydroxide PLUS points ensures more calcium hydroxide is released over a longer period and more space to release calcium hydration. This in vitro research aimed to evaluate the differences in the efficacy between Ca(OH)(2) paste and PLUS points as an endodontic dressing in eradicating E. faecalis growth inside infected single-rooted canals. Materials and methods: Thirty mandibular first premolars with single canals were extracted for orthodontic reasons and were prepared after cutting their crowns to standardize the length of the roots to 17 mm, root preparation, and isolating E. faecalis. The infected sample root canals were contaminated with the prepared bacterial suspension, and the sample was incubated in the incubator under air conditions at 37°C for seven days, counting the bacteria colonies. Then, the bacterial units were counted before applying the drug, applying Ca(OH)(2) paste in the first group and Ca(OH)(2) PLUS points in the second group. The bacterial units were counted, and the number of bacteria was compared between the two substances applied to the samples, measuring the intracanal dressings' effectiveness. Wilcoxon signed-rank tests were used to detect significant differences. Results: The results showed a statistically significant difference in the bacterial count of E. faecalis before and after applying the dressing of Ca(OH)(2 )paste from a mean of 11.89 to a mean of 3.18 (p=0.003) and no statistical difference in applying Ca(OH)(2) PLUS points from mean 11.98 to mean 10.50 (p>0.05). Conclusion: Within the limits of the current in vitro study, the Ca(OH)(2) paste cones were more effective than Ca(OH)(2) PLUS points in eradicating E. faecalis growth inside the infected single-rooted canals.