Torsional testing of the lightspeed nickel-titanium instrument system

Marsicovetere, Ennio S.; Burgess, John O.; Clement, David J.; Rió, Carlos E. del

doi:10.1016/s0099-2399(96)80064-1

Cited by 22 publications

(23 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The data of Marsicovetere et al (9) suggested an exponential relation. Direct comparisons cannot be made because different instruments were investigated in the three studies.…”

Section: Discussionmentioning

confidence: 94%

In Vitro Study of the Torsional Properties of New and Used ProFile Nickel Titanium Rotary Files

Yared

2004

Journal of Endodontics

View full text Add to dashboard Cite

The purpose of this study was to investigate torque and angle of rotation at fracture of new and used .06 ProFile instruments. ProFile sizes 15 to 40 were tested according to American National Standards Institute/American Dental Association Specification #28. Thirty new and used instruments were tested for each size. An analysis of variance was used to compare the torque and angle of rotation at fracture between new and used instruments. The relationship between torque at fracture and size of instrument was determined with a regression analysis. The used instruments had significantly lower torque and angle of rotation at fracture values compared with the new instruments (p < 0.0001). A stronger relationship was found between the size of the instrument and the torque at fracture for the new instruments (p < 0.0001) than for the used ones (p < 0.0001). In conclusion, the repeated use of .06 ProFile instruments significantly reduced the torque and angle of rotation at fracture.Instrument separation is a serious concern in endodontic therapy. Several studies have evaluated the influence of various factors on the fracture of nickel titanium (NiTi) endodontic rotary instruments (1-6). It is important for the clinician to have detailed research information to provide a rational basis for instrument selection. According to American National Standards Institute/American Dental Association (ANSI/ADA) Specification #28, the torsional properties of endodontic instruments can be evaluated as torque and angle of rotation required to cause instrument fracture (7). Previous studies have investigated the torsional properties of NiTi endodontic rotary instruments (2, 8 -10).Flexural fatigue (1) is not the major cause of NiTi rotary instrument fracture (10 -13). Instruments can lock into the canal (3) and be subjected to high levels of torsional stress leading to fracture. On the other hand, Sattapan et al. (8) showed that torque at fracture was significantly higher than torque during instrumentation. In their study, each set of instruments was used to prepare only one canal. Questions have been raised about whether repeated use of NiTi rotary instruments adversely alters their torsional properties, thus rendering them more prone to torsional fracture. To date, the influence of repeated use of .06 ProFile instruments (PRI)(Tulsa Dentsply, Tulsa, OK) on the torsional properties has not been evaluated.This study compared torque and angle of rotation at fracture of new and used .06 ProFile instruments and investigated the relation between size of instrument and torque at fracture. MATERIALS AND METHODS Evaluation of New InstrumentsSizes 15 to 40 .06 PRI were evaluated. Thirty new instruments of each size were tested for resistance to fracture by twisting according to ANSI/ADA Specification #28 (7). Two parameters were measured: torque (gcm) and angle of rotation (degrees) at fracture in clockwise rotation. A digital torque meter memocouple (A-Tech Instruments, Scarborough, Ontario, Canada) measured torque with an accuracy of Ϯ1 gcm ...

show abstract

“…The data of Marsicovetere et al (9) suggested an exponential relation. Direct comparisons cannot be made because different instruments were investigated in the three studies.…”

Section: Discussionmentioning

confidence: 94%

In Vitro Study of the Torsional Properties of New and Used ProFile Nickel Titanium Rotary Files

Yared

2004

Journal of Endodontics

View full text Add to dashboard Cite

show abstract

“…The other means to solve the problem is by using torque-controlled devices. As described by several authors [2,5,14,16] adjustable torque and reversal of rotation when the file reaches a predetermined torque level can prevent file breakage and tight locking of the file in the root canal. The torque at failure of nickeltitanium files depends on the size, cross-section, and taper of the instrument used [2,6].…”

Section: Instrument Failurementioning

confidence: 99%

Preparation of severely curved simulated root canals using engine-driven rotary and conventional hand instruments

Szep¹,

Gerhardt

Leitzbach

et al. 2001

Clinical Oral Investigations

View full text Add to dashboard Cite

This in vitro study evaluated the efficacy and safety of six different nickel-titanium engine-driven instruments used with a torque-controlled engine device and nickel-titanium hand and stainless steel hand instruments in preparation of curved canals. A total of 80 curved (36 degrees) simulated root canals were prepared. Images before and after were superimposed, and instrumentation areas were observed. Time of instrumentation, instrument failure, change in working length and weight loss were also recorded. Results show that stainless steel hand instruments cause significantly less transportation towards the inner wall of the canal than do nickel-titanium hand instruments. No instrument fracture occurred with hand instruments, but 30-60% breakage of instruments was recorded during instrumentation with the engine-driven devices. The working length was maintained by all types of instruments. Newly developed nickel-titanium rotary files were not able to prevent straightening of the severely curved canals when a torque-controlled engine-driven device was used.

show abstract

“…This identification was complemented by scanning electron microscopy (SEM) observation of the instruments before and after canal instrumentation. Considering that the only information regarding the dimensions of ProTaper instruments is the one given by the manufacturer, and that morphometric variations have been reported among other NiTi rotary instruments 8,9 , the dimensions of ProTaper instruments were also evaluated, in an attempt to correlate these measurements with the geometric and dimensional characteristics of the curved root canals prepared with them.…”

Section: Introductionmentioning

confidence: 99%

Geometric and dimensional characteristics of simulated curved canals prepared with proTaper instruments

2010

View full text Add to dashboard Cite

ObjectiveThis study identified which regions of ProTaper instruments work during curved root canal instrumentation.Material and methodsTwelve ProTaper instruments of each type, S1, S2, F1, and F2, were assessed morphometrically by measuring tip angle, tip length, tip diameter, length of each pitch along the cutting blades, and instrument diameter at each millimeter from the tip. Curved canals in resin blocks were explored with manual stainless steel files and prepared with ProTaper instruments until the apical end following four distinct sequences of instrumentation: S1; S1 and S2; S1, S2, and F1; S1, S2, F1, and F2. Image analysis was employed for measuring canal diameters. The diameters of the canals and diameters of the instruments were compared. Data were analyzed by one-way ANOVA and Tukey’s test.ResultsNo statistically significant difference was found between the canals and instrument diameters (p>0.05). The largest diameters in the end-point of the instrumented canals were obtained with F1 and F2 instruments and in the initial and middle thirds with S1 and S2 instruments.ConclusionsAll instruments worked at the tip and along their cutting blades, being susceptible to fail by torsion, fatigue, or the combination of these two mechanisms.

show abstract

Torsional testing of the lightspeed nickel-titanium instrument system

Cited by 22 publications

References 6 publications

In Vitro Study of the Torsional Properties of New and Used ProFile Nickel Titanium Rotary Files

In Vitro Study of the Torsional Properties of New and Used ProFile Nickel Titanium Rotary Files

Preparation of severely curved simulated root canals using engine-driven rotary and conventional hand instruments

Geometric and dimensional characteristics of simulated curved canals prepared with proTaper instruments

Contact Info

Product

Resources

About