Shaping ability of nickel-titaniumrotary files

Abstract

This study compared the shaping ability of nickel-titanium rotary files with different rake angle and radial land.The nickel-titanium files used in this study were Profile(Dentsply, Maillefer, Ballaigues, Switzerland), Hero 642(Micromega, Besancon, France), and K3(SybronEndo, Glendora, Ca, USA) file. Resin blocks substituted for root canals. 36 resin blocks were divided into 3 groups with 12 canals each. The time for canal preparation was recorded. The images of pre-and postoperative resin canal were scanned and those were superimposed. Amounts of canal deviation, total canal widths, inner canal widths, and outer canal widths were measured at apical 1, 2, 3, 4, 5, 6, and 7mm levels.The amount of canal deviation was the smallest in Profile group, and the time for canal preparation was the shortest in Hero 642 group. K3 group resulted in competent characteristics in both measurements. Positive rake angle seemed to result in fast shaping of root canal and radial land guide the instrument in center of the canals and around curvatures. Radial land also tended to reduce the sense of screwing into the root canal.The proper selection of the nickel-titanium file based on the knowledge about file design is needed for the safer, simpler and faster root canal therapy. [J Kor Acad Cons Dent 29(1):44-50, 2004]

Comparison of shaping ability between various hybrid instrumentation methods with ProTaper

“…Group H and group P took less instrumentation time significantly than the other groups in both operators. Despite the research that the rake angle affects the shaping time 24) , interestingly, group H did not have significant differences with group P. The result was interpreted that the time lapse was reduced significantly by the use of ProTaper S1 for pre-flaring of coronal two-thirds. Tip diameter of S1 corresponds to ISO size #17, and this made it easy to get not only coronal flaring but also apical preenlargement with the progressive greater taper.…”

Influence of root canal curvature on the screw-in effect of nickel-titanium rotary files in simulated resin root canal

“…9 The introduction of nickel-titanium alloy for the mechanically driven endodontic instruments has greatly simplified shaping of the root canal systems. 9,10 Reports have shown that nickel-titanium (Ni-Ti) instruments are two or three times more flexible than conventional stainless steel files and that they have more resistance torsional fracture. 11 Thus, these instruments have been found to be better than stainless steel instruments in maintaining the original anatomy and the shape and position of the apical foramen.…”

Comparison of screw-in effect for several nickel-titanium rotary instruments in simulated resin root canal

“…Reports on the efficacy and shaping ability of nickel-titanium rotary files have demonstrated their potential for root canal treatment. [3][4][5][6] Nickel-titanium instruments have a decreased tendency for canal transportation and therefore remain better centered. 7) Most studies have expected that these new instruments may enhance endodontic treatment with respect to both its quality and speed.…”