Comparative analysis of pericervical dentin reduction using three rotary file systems: A micro-computed tomography study.

Background: Maintaining pericervical dentin (PCD) thickness is crucial for the long-term prognosis of endodontically treated teeth. Root fractures are closely linked to PCD loss, which is influenced by the type of rotary file system used.

Aims: This study compared the effect of three rotary file systems - TruNatomy, OneShape, and ProTaper Gold - on PCD thickness in the mesiobuccal root of mandibular molars using micro-computed tomography (micro-CT).

Materials and methods: Twenty-seven mandibular first molars were mounted on wax and scanned using micro-CT before and after instrumentation. Samples were randomly divided into three groups (n = 9) and instrumented per manufacturer guidelines. PCD thickness was measured at 2 mm and 4 mm below the cementoenamel junction (CEJ) on mesial, distal, buccal, and lingual surfaces. Data were analyzed using a paired t-test, one-way analysis of variance, and Tukey's post hoc test (P < 0.05).

Results: No significant difference was observed at 4 mm below the CEJ. However, TruNatomy showed significantly less dentin removal at 2 mm (P = 0.003).

Conclusions: TruNatomy preserved the most dentin, followed by ProTaper Gold and OneShape. Selecting appropriate rotary instruments can help minimize dentin loss and enhance the longevity of endodontically treated teeth.