Effects of Sequential Antimicrobial Phases on Root Canal Microbiome Dynamics in Two-Visit Treatment of Primary Apical Periodontitis: A Longitudinal Experimental Study.

Seda Tezcan Ülger | Gönül Aslan

Abstract: Background: Effective management of primary apical periodontitis depends on understand- ing the dynamic interactions within the root canal microbiome. This study aimed to investigate the effect of sequential antimicrobial phases on the root canal microbiome during a two-visit treatment approach, with a focus on calcium hydroxide medication. Methods: Samples were collected from three teeth across four treatment phases: initial infection (S1), after chemomechanical preparation (S2), after intracanal medication (S3), and after a final flush (S4). DNA was extracted, and the V3–V4 regions of the 16S rRNA gene were sequenced using Illumina MiSeq. Sequencing data were analyzed with QIIME 2, and differentially abundant taxa were identified using linear discriminant analysis effect size (...