High precision, simulated cutting efficiency measurement of endodontic root canal instruments: influence of file configuration and lubrication.

A high precision method is presented for measurement of root canal instrument cutting efficiency in pure, linear movements. Operator-independent instrumentation is achieved by means of an automatic, mechanical test rig mounted as an accessory in an Instron tensile testing machine. It is now possible to do reliable cutting simulation that closely represents clinical motions.

[Experimental study of the efficacy of endodontic instruments in pure traction].

A method to test the efficiency of traction is developed on bovine bones, according to a mechanical mode. This procedure concern specific dynamics of the M.M.

[A periapical lesion does not condemn the tooth].

Through three clinical cases, the authors demonstrate that large lesion do not compromise the teeth. Endodontic surgery could be used as the ultimate solution when classical root canal therapy fails to repair the lesion.