Lifespan of One Shape Files used in Severely Curved Canals in Resin Blocks and Extracted Teeth

The investigation traced the lifespan of One Shape files used in severely curved canals of resin blocks and extracted teeth. One hundred canals were shaped and all instruments worked till their fracture. The average lifespan in the group of artificial canals was 4.631.30 canals and of extracted teeth - 8.401.34 canals. The cumulative survival of tested files in both groups revealed significant difference. One Shape files manifested a lifespan similar to that of other NiTi systems with continuous rotation. Experimental protocols and obtained results should be interpreted very carefully, always having in mind the origin of the treated medium.