BACKGROUND: Calcium hydroxide a popular intracanal medicament used for persistent infections, and root perforations. However, it can impair sealer adaptation to dentin walls, increasing leakage risks. Therefore, complete removal before obturation is essential.
OBJECTIVES: To evaluate the residue of two types of Ca(OH)2 paste after using master apical file with syringe needle irrigation, sonic, and passive ultrasonic activation, assessed via stereomicroscope.
METHODS: Sixty extracted single-rooted mandibular premolars were instrumented using PROTAPER NEXT rotary files to file X3. Thirty canals were filled with oil-based Ca(OH)2 (Metapex) and 30 with aqueous-based Ca(OH)2 paste (Metapaste). The teeth were divided into two groups: Group A (Metapex) and Group B (Metapaste). After one week, the bulk of Ca(OH)2 was removed using a #15k file to the working length with 3 ml of 2.5% NaOCl. Furtherly each group was subdivided into three subgroups for removal methods: A1, B1 (Master Apical File & Syringe Needle Irrigation), A2, B2 (PUI), A3, B3 (EDDY). Samples were sectioned longitudinally, scanned with a stereomicroscope, and images were analyzed using ImageJ software. The Kuga Scoring system evaluated remaining Ca(OH)2, and statistical analysis was performed using Three-way ANOVA with a significance level of P=0.05.
Results: None of the techniques achieved complete Ca(OH)2 removal along the entire canal length. PUI and EDDY showed superior removal compared to MAF in both groups, with the coronal third having the most residual paste.
CONCLUSION: EDDY and PUI are more effective than MAF in removing calcium hydroxide.