A comparison of two nickel-titanium instrumentation techniques in teeth using microcomputed tomography

Aim The aim of the study was to compare the shaping of root canals by two n ice-titanium instrumentation techniques using microcomputed tomography (MCT ). Methodology Ten mandibular first molar teeth (30 canals) that had intact cr owns and fully formed roots were scanned using MCT. Fifteen canals were ins trumented using NiTiFlex hand files (Maillefer) using balanced force. The r emainder were instrumented using prototype Profile 0.04 Taper instruments ( Dentsply) in a crown-down manner to an apical size ISO 25. The teeth were s canned again following instrumentation. The two instrumentation techniques were compared in a total of 27 canals. The area of dentine removed at prede termined levels (2.0, 3.0, 4.5, 6,0, 7.5 mm) from the apex was measured. Tr ansportation and centring were recorded. Images constructed at these levels were compared with video images of equivalent physical sections created af ter the second scan, The volume of dentine removed in the apical 7.5 mm of the root canals of each tooth was calculated and the different techniques c ompared. Rendered three-dimensional images were used to assess the preparat ions qualitatively. The time taken for preparation was recorded. Results There was no significant difference between hand instrumentation wi th NitiFlex files and machine instrumentation with prototype Profile 0.04 T aper instruments for any of the variables tested. Conclusions Both techniques produced well centred and tapered preparations.