Distinct Microbiota and Functional Pathway Profiles Define Success and Failure in Regenerative Endodontic Treatment
Leimarembi Devi Naorem, Alina Wikström, Peter Quach, Lokeshwaran Manoharan, Ronald Ordinola‐Zapata, Olena Rakhimova, Malin Brundin, Nelly Romani VestmanABSTRACT
Aim
To characterize the intracanal microbiota and identify key microbial taxa and functional pathways associated with regenerative endodontic treatment (RET) outcomes.
Methodology
In this observational cohort study, 196 samples were collected at five time points from external tooth surfaces (T1, T4) and root canals (T2, T3, T5). The V3–V4 hypervariable region of 16S rRNA gene was amplified and sequenced on the Illumina MiSeq platform. Sequence data were pre‐processed using QIIME2 and DADA2 to generate amplicon sequence variants (ASVs), classified against the eHOMD database. Microbial diversity, differential abundance, and Receiver Operating Characteristic (ROC) analyses were performed using R statistical software. Functional profiles were predicted using PICRUSt2.
Results
RET induced dynamic shifts in the root canal microbiome, with initially predominant phyla including Actinomycetota, Bacillota, Bacteroidota, Fusobacteriota and Pseudomonadota. Cases with treatment failure consistently showed a higher relative abundance of Fusobacteriota than successful cases. Alpha diversity varied across time points, with outcome‐specific differences observed only at T3; beta diversity differed significantly by time point but not by treatment outcome. Differential abundance analysis at T5 revealed enrichment of
Conclusions
RET alters the intracanal microbiome, with taxa identified following intracanal dressing exhibiting moderate predictive potential as biomarkers for treatment outcome, thereby contributing to early prognosis and informing RET strategies.