In article the comparative assessment of quality of machining of roundish and oval root channels of singleroot teeth by systems nickel – the titanium files K3, Pro-Taper, RaCe is given. Criteria of quality of preparation of the root channel are defined. Good results are received when processing clumsy channels of teeth with a length less than 25 mm and a roundish form of the root channel. During research it is established that the root channels having an oval form can’t be qualitatively processed only by systems of the rotating files.
the root channel, machining, nickel-titanium files