An <i>in vitro</i> study of the torsional properties of new and used K3 instruments
Bibliographic record
Abstract
AIM: To compare torque and angle of rotation at fracture of new and used K3 rotary instruments. The relation between size of instrument and torque at fracture was also investigated. METHODOLOGY: Nickel-titanium (Ni-Ti).06 K3 rotary instruments were used in a crown-down manner at 300 r.p.m. to prepare canals in resin blocks. The torque and angle of rotation at fracture of new and the used Ni-Ti.06 K3 rotary instruments (sizes 15-40) were determined according to ANSI/ADA Specification no. 28. Analysis of variance was used to compare the torque and angle of rotation at fracture amongst the different sizes of the new instruments and between new instruments and instruments of the same size, which had been used in resin blocks (alpha = 0.05). The relationship between torque at fracture and size of instrument was subjected to regression analysis. RESULTS: Torque at fracture of the new instruments increased significantly with the diameter. The used instruments (sizes 15, 20, 30, 35 and 40) had lower torque at fracture compared to the new ones (P < 0.0001). The means of angle of rotation at fracture between the different sizes of new instruments were significantly different (P < 0.0001) except for sizes 15-20 (P = 0.2561). The used instruments (sizes 20-40) had lower angle of rotation at fracture compared to the new ones (P < 0.05). A linear relationship was found between the size of the file and the torque at fracture for the new instruments (r2 = 0.84; P < 0.0001) and the used ones (r2 = 0.82; P < 0.0001). CONCLUSIONS: In general, the results suggested that the torque and angle of rotation at fracture were significantly affected by the repeated use of.06 K3 instruments in resin blocks.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".