Remaining root dentin thickness in mesiobuccal canals of maxillary first molars after attempted removal of broken instrument fragments
Bibliographic record
Abstract
The aim was to measure the minimal thickness of the remaining canal wall dentine in the mesiobuccal roots of maxillary first molars using a virtual model to simulate the attempt to remove fractured instruments. Thirty-seven molars were scanned by micro-computed tomography. The application framework for the simulation of the attempt to remove a broken instrument was constructed. The staging platform was created and followed by the use of ultrasonic tips to trephine dentine around the fragment to reveal the coronal 1.5 mm. The minimum canal wall thickness in the mesiobuccal roots was then measured. The concavity groove was found on all the distal aspects of the mesiobuccal root. The minimum thickness of the remaining canal wall distally to the canal was significantly thinner than mesially to the canals when sizes 25/0.06 and 25/0.02 instruments were broken at 3 and 5 mm away from the canal orifice. When the sizes 20/0.02 and 25/0.06 instruments were broken at 5 mm away from the canal orifice, the minimum thickness of the distal dentine wall was only 300-400 μm which was significantly less than when the instrument was broken at 3 mm.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
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".