Effects of radiant exposure and distance on resin-based composite polymerization.
Bibliographic record
Abstract
PURPOSE: To evaluate the hardness profile of three resin-based restorative composites (RBC) (Filtek Z250XT, Filtek One Bulk Fill, Filtek Bulk Fill Flow) polymerized by a multi-wave curing light. METHODS: Specimens (n= 12) were prepared by inserting 2 mm RBC increments into a split-mold and polymerized from the top using either 20- or 40-second exposure times. Specimen curing was performed directly at a 1 mm distance (control-group) or through an ivorine-tooth slot preparation at a 5 mm distance (experimental-group). Specimens were stored (37 ± 1°C/24 hours), then subjected to Knoop indenter (25g/5 seconds). Specimens' KHN values were obtained from the upper and lower surfaces. Relative hardness (RH) (lower-to-upper ratio) was calculated for each specimen. Data were analyzed with three-way ANOVA and Tukey's HSD (α= 0.05). RESULTS: There was no significant RH difference among RBCs in the control group, regardless of the exposure time (P> 0.05). Average RH ratios for all RBCs tested in this group were greater than 0.80. However, the average RH values of the experimental RBC group were significantly lower. The RH for Z250 was 0.39 in the 20-second group, while RH was 0.63 in the 40-second group. BF had an RH ratio of 0.70 in the 20-second and 0.72 in the 40-second group, while One Bulk had a ratio of 0.65 in the 20-second and 0.71 in the 40-second groups. Doubled exposure time substantially increased RH of all tested materials at a 1 mm tip-to-material distance. Clinically relevant 5 mm light-tip to material-surface distance significantly reduced polymerization efficacy of RBC specimens, regardless of the exposure time. CLINICAL SIGNIFICANCE: Adequate light-polymerization of resin-based direct restoratives is necessary for long-term clinical success. Polymerizing Class 2 restorations is challenging due to a hard-to-reach location and an increased distance between the light source and the restorative material. Insufficient polymerization is often seen at the bottom of the proximal box of the Class 2 cavity, with a detrimental effect on restoration longevity.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 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".