Analysis of Torque and Force with Differently Tapered Rotary Endodontic Instruments In Vitro
| Autor: | Charlotte Schrader, Ove A. Peters |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Dental Stress Analysis
Dental Instruments Materials science Statistics Nonparametric symbols.namesake Nickel Forensic engineering Torque Pliability General Dentistry Titanium Analysis of Variance business.industry Dental alloys Fatigue testing Equipment Design Structural engineering Dental instruments Elasticity Pearson product-moment correlation coefficient Equipment failure symbols Equipment Failure Stress Mechanical Dental Pulp Cavity business Root Canal Preparation Dental Alloys |
| Zdroj: | Journal of Endodontics. 31:120-123 |
| ISSN: | 0099-2399 |
| DOI: | 10.1097/01.don.0000137634.20499.1d |
| Popis: | The aim of this study was to compare torques and forces developed by two sequences of nickel-titanium rotary instruments, using only .04 taper instruments or a combination of .04 and .06 tapers, respectively. Curved canals in plastic blocks were shaped in a torque-testing device; torque, force, contact areas and numbers of working rotations were determined. Analysis of variance and Pearson correlation coefficients were used to compare the two sequences. Mean torque ranged from 0.2 +/- 0.03 to 3.19 +/- 0.28 Ncm and was higher for instrument sizes 25 to 45 in group A. Mean vertical forces ranged from 1.49 +/- 0.54 to 12.0 +/- 3.5 N; there were significant correlations between torque and force as well as between torque and contact areas. Numbers of rotations were lower in the combined .04 and .06 sequence. An instrumentation sequence encompassing various tapers seems to be safer regarding torsional and fatigue failure compared to a sequence that used one single taper. However, the former sequence requires the use of more instruments. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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