EFFICACY OF FIVE TECHNIQUES FOR THE REMOVAL OF CALCIUM HYDROXIDE FROM STRAIGHT AND CURVED ROOT CANALS - MICRO-CT STUDY

Introduction: The role of intracanal medications in endodontic treatment is indisputable, but their removal before endodontic treatment is imperative. Purpose: To compare the effectiveness of five different calcium hydroxide removal techniques in teeth with straight and curved root canals by micro-computed tomography. Material and Methods: Ninety-two extracted teeth, 46 with straight canals and 46 with curved canals, were prepared with ProTaper Next to full working length and filled with calcium hydroxide. They are randomly divided into 5 groups depending on the applied technique. Group 1 (n=8) syringe and needle, group 2 (n=8) passive ultrasonic irrigation, group 3 (n=8) laser (Er: YAG), group 4 (n=8) EndoActivator and group 5 (n=8) EndoVac, and control group (n=6) without medication. Micro-computed tomography was used to assess residual calcium hydroxide. IBM SPSS Statistics 26 software was used. Results: The greatest difference in the volume of residual calcium hydroxide between straight and curved root canals was found in syringe and needle, and ultrasonic irrigation. In the apical third, the residual volume in straight canals is 0.200 mm3, and in curved canals 0.666 mm3. At an average position, it is 0.272 mm3 for straight canals and 0.344 mm3 for curved canals. Conclusion: In straight root canals, the calcium hydroxide residue is found along the entire length of the canal, while in curved canals, it is mostly in the apical third. The average amount of residue in curved root canals is 3-4 times greater than in teeth with straight canals.