Cleaning efficacy of two apical preparation regimens following shaping with hand files of greater taper

Aim The aim of this investigation was to assess canal cleaning following sh aping with hand files of greater taper. Methodology Thirty mesial canals and 30 distal canals in mandibular molars were prepared with .08 and .10 hand files of greater taper, respectively Fo llowing initial preparation, 0.02 instruments were used incrementally short er in a stepback manner In half the canals instrumentation was performed to size 351 mm short of the canal terminus. In the other half the series was continued through to size 60 using stepback increments of half to one milli metre as appropriate (foramen size was maintained at size 20 in all groups) . Sodium hypochlorite (4.5%) and REDTA (17%) were used as irrigants for all groups, Cleaning efficacy was evaluated by scoring the amount of remaining debris using a light microscope (x50) and calibrated eyepiece micrometer ( range 0-3). Results Canals stepped back through to a size 60 were significantly cleaner than those instrumented to a size 35 only (Mann-Whitney P < 0,05). Conclusion Refining the apical region of canal preparation by stepping back through to a size 60 reduced remaining debris following shaping with files of greater taper.