SHAPING ABILITY OF PROFILE.04 TAPER SERIES-29 ROTARY NICKEL-TITANIUM INSTRUMENTS IN SIMULATED ROOT CANALS .1.

The aim of this study was to determine the shaping ability of ProFile, 04 Taper Series 29 nickel-titanium instruments in simulated canals. A total of 40 simulated root canals made up of four different shapes in terms of angle and position of curvature were prepared by Profile inst ruments using a step-down approach, Part 1 of this two-part report des cribes the efficacy of the instruments in terms of preparation time, i nstrument failure, canal blockages, loss of canal length and three-dim ensional canal form. The time necessary for canal preparation was not influenced significantly by canal shape, No instrument fractures occur red but a total of 52 instruments deformed, Size 6 instruments deforme d the most followed by sizes 5, 3 and 4. Canal shape did not influence significantly instrument deformation. None of the canals became block ed with debris and loss of working distance was on average 0.5 mm or l ess, Intracanal impressions of canal form demonstrated that most canal s had definite apical stops, smooth canal walls and good flow and tape r. Under the conditions of this study, ProFile.04 Taper Series 29 rota ry nickel-titanium instruments prepared simulated canals rapidly and c reated good three-dimensional form. A substantial number of instrument s deformed but it was not possible to determine whether this phenomeno n occurred because of the nature of the experimental model or through an inherent design weakness in the instruments.