engleski

Endodontic irrigation with two different needles ; computional fluid dynamics analysis based on an ex vivo model

The aim o f this study was to analyze the irrigation efficiency of two needle types in a realistic root canal , odel using Computional fluid dynamics (CFD). An extracted human maxillary canine was decoronated at the enamel -cement junction. After cleaning and shaping, the prepared root canal was scaned by computed, tomography. A 3D object representing the prepared root canal was obtained using Scan IP and computer assisted design (CAD) software Catia. an open-end notched 27G irrigation needle with closed tip was measured and a CAD model created, providing a plotting template for a virtual side-vented irrigation needle with closed tip. Both 27G, virtual needles were placed at 0.9, 4.5 and 9 mm from the apical terminus of the prepared root canal model and, after merging with root canal, models were exported to comercial CFD solvent software Star-CCM. Four different irrigant inlet velocity values were set, determined by clinicaly reproducible flow rates (0.1, 0.2, 0.3 and 0.4 ml/s), for each needle type and position. CFD analysis of irrigant flow pattern, velocity and pressure was performed. Open-ended needles had satisfactory flow patterns at 0.9 and 4.5 mm for all flow rates analyzed, while side-veneted needles were effective at 4.5 mm distance only with 0.4 mL/s, and at 0.9 mm with 0.2-0.4 mL/s flow rates. Irrigant pressure in apical portions of canals was significantly increased in the case open-ended comparing to side-vented needle. On the basis of this ex vivo investigation, open-ended irrigation needles had efficent irrigation at lower flow rates compared to side-vented closed-ended needle of the same diameter, though the latter provides decreased irrigant pressure and safer irrigation.

root canal; fluid dynamics; irrigation

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