HOW THE WORKSPACE DECIDES
Sanitized, not sealed.
A free tool from TrazaLab, dental lab software for dental labs and dentists.
STL repair online is the tool above. This chapter is the same decisions, written out: what stays in the browser, what conservative repair is allowed to touch, which openings it will not invent a floor for, and when reconstructive work is refused.
01
Keep the file.
Drop a binary or ASCII STL on the workspace. Analysis and conservative repair run in the browser. The mesh is not sent to TrazaLab’s internal laboratory production engine on that path. You can mark open edges, non-manifold junctions, and degenerate triangles, then download a sanitized copy without uploading the file. That is the default on /stl-file-repair-online.html.
The Spanish twin is /stl-fixer.html, with reciprocal hreflang. Both URLs mount this public component. Neither mounts the protected production engine, case approvals, or QA gates used inside laboratory work. A job here does not attach the file to an account. If the mesh must travel with odontogram, prescription, evidence, and laboratory instructions, that is the case workflow — linked at the foot of this page — not a silent import from the public tool.
The local budget is 75 MB. Dental arches are often larger, frequently past 400 MB. Those files are not rejected for size alone. They can continue on the isolated reconstructive engine, up to 500 MB, after you authorize that job, at no charge. If the file sits outside the browser’s safe memory budget, the workspace says so. It does not fake a finished local analysis. The size stripe on the comparison block is the same rule, restated: large is normal; silence is not.
Commercial analytics on TrazaLab marketing pages do not send filenames, SHA hashes, emails, mesh geometry, or patient identifiers as event parameters. Allowed fields include route, tool, size bucket, locale, and whether a unit was confirmed. Conservative work never needed a server copy. Reconstructive work stores an encrypted temporary copy only after you authorize it, and that copy is deleted after 24 hours.
02
Confirm the unit.
Nothing dimensional is trusted until you confirm millimeters or inches. The report does not guess. Until the unit is set, size stays unconfirmed and several actions wait. That is deliberate. A crown scan exported in inches and read as millimeters is not a topology bug; it is a scale lie, and this page will not launder it into a pretty bounding box.
Surface area and bounding dimensions follow the unit you confirm. Volume appears only when the mesh supports that measurement. Otherwise the panel shows that volume is not available. An empty volume is not a crash. It is the honest state of an open or inconsistently oriented shell. Triangle count and component count still render; they do not pretend to be millimeters.
The demo on this page is an IOS upper arch from Bits2Bites patient 01. Cite the paper. Public commercial use of that dataset remains pending authorization, as the workspace states. BodyParts3D is not the public demo; it stays in fragment-repair tests. The demo exists so you can see markings on a real arch before you drop a patient file. It is labeled DEMO IOS · UPPER ARCH. It is not a TrazaLab case, and it is not a promise that your trim will classify the same way.
03
Read the inventory.
The health report is not a traffic-light score. Findings are named with the same labels you see on the mesh: detected openings (open edges), incorrect junctions (non-manifold), inverted faces, collapsed or duplicate faces, overly narrow faces, very small fragments, and surface intersections split into within-piece versus between-pieces when the analysis can tell them apart.
A typical intraoral scan leaves a residual open contour at the trim. The residual-open classifier is not a mood. It requires no non-manifold edges, no within-shell intersections, at least 64 open edges, no branched boundary networks, no leftover boundary chains, between one and four boundary loops, and at most two components. Tiny missing-face holes stay blockers. They are not dressed up as an open scan. When that residual pattern matches, the decision copy is blunt: it is a residual open surface. The tool keeps the open contour. It does not force a watertight STL or a zero-error report.
If within-shell intersection checks hit their limit, the review is marked incomplete. A clean result is not shown when the check did not finish. Other decision states match the inspector. We can clean inverted, damaged, or duplicate faces without moving mesh points. We can fix part of the file now when some faces are cleanable and some openings still need intervention. The file needs additional repair when damaged openings, incorrect junctions, or within-piece intersections should be reviewed before the laboratory sees the export. Signals worth reviewing means no within-piece topological blocker, but between-component intersections, narrow faces, or fragments still need a person.
04
Move no vertices.
Free conservative repair is the first action after a local analysis. It cleans damaged faces or orientation without deforming geometry. Vertices are not moved. Degenerate or duplicate triangles can be removed. Faces can be reoriented. The engine id for that path is trazalab-conservative-no-displacement/v2. If you need a sentence for a colleague: the shape is not displaced.
The proof panel is labeled VERIFIED CHANGES. Conservative mode prints Conservative repair · vertices not moved. When geometry was not displaced, the line is Shape was not displaced. Counts: faces removed, faces reoriented, open edges before → after, remaining incorrect junctions. Sampled deviation p95 appears when a reference mesh exists for that job. The operation log is the audit trail, not decoration. “Repaired” without that inventory is exactly what this page refuses to be.
After conservative repair you compare the original and the result in the same viewer, download the revised binary STL, and download a JSON review report. If independent verification does not match, download stays hidden. The result may be kept for diagnosis. It is not presented as verified. The verdict is RESEND. When the only remaining issue is an open surface this path must not invent a floor for, no automatic shape change is applied to that border. The report keeps the zones that still need repair or open-surface review.
05
Keep the border.
Reconstructive hole filling is not “close everything.” Dominant per-component openings that look like an intentional scan border are classified as such and never filled. The public phrase is the same as the engine: open scan border — we do not invent a floor. Secondary loops can remain defect candidates under a bounded hole policy. Only the dominant opening on a component may be treated as that border.
A loop is treated as a scan border when it is the dominant opening and it is large enough in edge count or span ratio, or when it exceeds the defect-hole edge cap. Defaults in the shipped engine include a defect-hole edge cap of 192, a scan-border minimum of 64 edges, and a span-ratio floor of 0.12, with scan-border preservation on unless turned off. Bounded defect fill also refuses more than 32 holes in one pass, a span ratio above 0.05, and a loop that is not planar enough for the triangulation. Those numbers are policy, not a promise that every laboratory’s trim will classify the same way.
Other skip reasons are left raw in the preview when they are not the scan-border phrase: hole-count-limit, edge-count-limit, opening-too-large, opening-not-planar, ambiguous-or-self-crossing-loop, rejected-network, non-manifold-or-inconsistent-input. Reconstructive fill does not run on a mesh that still has non-manifold edges or winding conflicts. That is why conservative cleaning exists first. If reconstructive repair would not change the mesh, it is not run. An identical STL is not sent through reconstruction for theater.
06
Reopen the export.
After conservative repair the workspace reopens the file it is about to give you. It reanalyzes that export. It stores SHA-256 fingerprints of the original and the result. Reopening is the difference between a filter that says “fixed” and a tool that can show you the residual inventory on the thing you will actually send.
The JSON report is the review before and after, not a marketing certificate. Take it if you need a record next to the STL. It does not replace a laboratory QA gate. It does not attach to a TrazaLab case. It is evidence of this public job. Independent verification failing is not a retry hint in small type. Download stays hidden. Verdict: RESEND.
The comparison table’s TrazaLab column for verification is this same loop: reopen, reanalyze, SHA-256. JustFixSTL, iamRapid, Formware, and Fusion did not publish that loop on the pages TrazaLab reviewed on 9 August 2026. “Not published” means it does not appear there. It does not prove those products lack a private equivalent. TrazaLab did not run a bake-off.
07
Isolated reconstruction.
Isolated reconstructive repair is included at no charge when you authorize the upload and the file is eligible. The engine id is trazalab-fragment-reattachment-and-bounded-hole/v2. It can reattach separated fragments and fill eligible bounded defect holes. Thickness sampling, sampled deviation, and a geometric readiness PDF belong to that suite. Hollow and drain holes are not offered on the public button. The public CTA keeps hollow and add-drain-holes off.
Fragment matching on the shipped reconstructive path widened under the same safety vetoes: more fragments considered (twelve instead of eight), a wider boundary-edge budget (384 instead of 256), a slightly lower receiver-face ratio (1.1 instead of 1.2), a slightly higher travel ratio (0.9 instead of 0.75). Those are engine defaults, not a guarantee that every fractured scan will reassemble. The Bits2Bites public demo remains ineligible for reconstruction when the honest reason is the scan border — not a silent no-op.
Thickness is sampled on closed, consistently oriented shells when those shells exist. Open multi-shell results can still receive thickness on the closed components. Open-only meshes report thickness as not available. Deviation p95 is sampled against the reference mesh for that job. It is not a certified clinical CAD comparison. Reconstructive repair, thickness, deviation, and the PDF stay locked until the isolated job finishes. The server checks whether reconstruction would add value before running it.
08
Geometric verdict only.
The package eyebrow is GEOMETRIC PACKAGE · VERDICT. Two labels: geometrically clear, or review. Geometrically clear means a verified export with no residual blockers in the measured geometric scope. Review means declared geometric residuals remain; the laboratory should review before manufacturing. Pass is not a fabrication unlock. This public URL cannot open TrazaLab’s production QA gate.
The disclaimer on the gate is the product, not a footer afterthought. Geometric verdict only. Not a clinical, fit, occlusion, or print-success guarantee. Deviation is sampled. This page will not say the restoration will seat, the contact will hold, or a printer will succeed. Those decisions belong with the case, the prescription, and the laboratory — which is why remake prevention is a different route than this sanitizer.
If you needed a watertight seal, CAD-ready mesh, or a promise that every STL can be repaired, this is the wrong page. The claim ledger forbids those sentences. The engine is built to refuse them in behavior as well as in copy. Minimum thickness on this page is a geometric sample. It does not prove printability. The limit line under the comparison table says the same thing in one breath.
09
Name the verdict.
The inspector does not invent a house style for bad news. It uses the decision titles already on the panel. It is a residual open surface — typical intraoral trim; the open contour stays. We can fix part of the file now — some faces are cleanable without changing shape, and some geometry still needs intervention. The file needs additional repair — damaged openings, incorrect junctions, or within-piece intersections should be reviewed before the laboratory sees the export.
The review needs to finish — within-shell intersection checks hit their limit; a clean result is withheld. We can clean this file now — inverted, damaged, or duplicate faces can be corrected without moving mesh points. The file has signals worth reviewing — no within-piece topological blocker, but between-component intersections, narrow faces, or fragments still need context. The file passed the basic review — nothing in this tool’s checks.
After conservative repair the titles shift. We cleaned what was safe; the open surface remains. We fixed what was safe and show what remains — damaged openings, incorrect junctions, or remaining within-piece intersections stay marked; advanced reconstruction is included when the file is eligible. The revised file is ready to download — the mesh was re-checked after the change and this review found no problems inside its scope. If you cannot map a colleague’s “just close it” request onto one of those sentences, the request is not this tool’s job.
10
What you download.
Conservative success offers a revised binary STL and a JSON review report. Reconstructive success, after independent verification, offers a reconstructive mesh and a PDF package labeled go/no-go. The PDF is a geometric readiness certificate for this isolated job. It is not a laboratory release, not a TrazaLab case attachment, and not a print-success letter.
Downloads stay locked while reconstructive work is still running. They stay hidden when verification does not match. They are not offered when reconstruction would not change the mesh. Hollow and drain are engineered in the reconstructive engine and remain off the public button, so you will not download a hollowing pass from this URL.
Continue in TrazaLab on this page is a handoff. This job does not attach the case to an account automatically. Odontogram, digital Rx, evidence, and laboratory send live in the TrazaLab case workflow. Pricing, when you want an account, is /pricing.html so you pick the plan. Do not treat a sanitized STL from this page as a completed case.
11
Not the lab engine.
/online-stl-viewer.html is inspect-only: orbit, section, wireframe, geometry inventory. Conservative repair, reconstructive repair, and downloads for English search live here. Do not treat the viewer as a second repair engine. The viewer points at this URL when the next step is sanitize and download.
Dental STL analysis as a connected-case story is /dental-stl-analysis/. Remake prevention — missing clinical information, evidence, and review gates before fabrication — is /remake-prevention/. Surgeon-facing case release is /for-surgeons/. The funnel under this chapter lists those destinations without pretending this sanitizer already ran them.
The comparison table against JustFixSTL, iamRapid, Formware, and Fusion is only what each official page published, reviewed 9 August 2026. TrazaLab’s column is this workspace: browser conservative repair, isolated reconstructive suite when authorized, reanalysis, SHA-256 fingerprints, and defects left marked when a closure would be invented. If a competitor’s marketing page said “automatic STL repair,” that is what the table records. It is not TrazaLab’s method, and it is not a dare to close your IOS floor.
THREE STAGES · SAME FILE
File, analysis, result.
Drop or demo
Binary or ASCII STL. Seventy-five megabytes in the browser, five hundred on the isolated engine. Unit unconfirmed until you say millimeters or inches. Demo is Bits2Bites patient 01 upper arch, cited, not a patient case.
Inventory on the mesh
Openings, junctions, inverted and collapsed faces, narrow faces, fragments, within-piece versus between-pieces intersections. Residual open surface kept. Incomplete intersection checks declared. No fake zero.
Proof, then export
Conservative: vertices unmoved, proof panel, reopen, SHA-256, JSON. Reconstructive only if you authorize it and it would change the mesh. Geometric clear or review. RESEND if verification fails.
TWO ENGINES · ONE PAGE
In the browser
Parse, preview, inventory, conservative repair, SHA-256, JSON report, before/after. Up to 75 MB. No upload to the laboratory production engine. Vertices stay. Open scan borders stay.
This is the path that answers “is my STL uploaded to TrazaLab?” with no, unless you later authorize reconstructive work. The 3D workspace above is this engine. The chapter you are reading is not a second tool.
On the isolated engine
Only after you authorize it. Up to 500 MB. Fragments and eligible holes, thickness when shells allow, sampled deviation, PDF. Deleted after 24 hours. Hollow and drain stay off the public button.
The server can refuse the job when the estimate says the mesh would not change, when the scan border is the whole story, or when blockers still need conservative cleaning. Refusal is a product feature.
SAME WORDS AS THE INSPECTOR
The labels are the product.
Detected openings. Open edges and opening networks on the mesh. A residual IOS trim is kept as an open contour, not filled into a fake floor.
Incorrect junctions. Non-manifold edges. Conservative repair does not invent a manifold seal. Reconstructive fill is blocked while these remain with winding conflicts.
Inverted faces. Orientation / winding conflicts. Conservative repair may reorient faces without moving vertices.
Collapsed or duplicate faces. Degenerate or repeated triangles. Conservative repair may remove them. The proof panel counts faces removed.
Overly narrow faces. Sliver geometry the inventory can flag. It is a signal worth reviewing, not a license to rebuild the arch.
Surface intersections. Split into within-piece and between-pieces when the check can tell. An unfinished within-shell check is incomplete, not a silent pass.
Very small fragments. Loose pieces the reconstructive path may reattach when eligible. Public reconstruction is refused if the estimate says the mesh would not change.
This geometric review does not prove fit, occlusion, minimum thickness, or printability.
Public reconstructive work does not attach the STL to a TrazaLab case, and does not run hollow or drain on the public button.
STL repair questions
Is my STL uploaded to TrazaLab?
Analysis and conservative repair run in your browser. The file is not sent to the internal laboratory production engine. Only if you authorize reconstructive repair is an encrypted temporary copy stored (up to 24 hours) to complete that job.
What does this tool repair?
Conservative repair cleans degenerate or duplicate triangles and orientation without moving vertices. It flags open edges and non-manifold edges; it does not invent a watertight seal. Reconstructive repair (included, at no charge) can reattach fragments and fill eligible holes when you authorize upload and the file is eligible.
Is this the same internal production tool?
No. This page is a separate public component. The protected production engine, case approvals, and QA gates are not mounted on this route.
What does the free reconstructive suite include?
Isolated reconstructive repair, thickness sampling when the mesh allows, a geometric readiness PDF certificate, and signed downloads. Hollow and drain are not offered on the public button. It does not promise fit, occlusion, or print success.
Does reconstructive repair close the open intraoral scan border?
No. Dominant openings classified as intentional scan borders are preserved. The tool does not invent an IOS floor. Only bounded defect holes can remain eligible. If reconstructive repair would not change the mesh, it is not run.
How large an STL can I review here?
Browser analysis handles up to 75 MB. Larger dental STLs can use the isolated engine up to 500 MB after you authorize reconstructive repair. Files are not rejected only because they are large. Confirm millimeters or inches before reading dimensions.
What do SHA-256 fingerprints and the JSON report prove?
After conservative repair the export is reopened and reanalyzed. Fingerprints identify the original and the result. The JSON report stores the review before and after. If independent verification does not match, download stays hidden and the verdict is resend.
When is thickness shown as not available?
Thickness is sampled on closed, consistently oriented shells. Open-only meshes report thickness as not available. That empty reading is intentional. Minimum thickness on this page is geometric, not a print-success or fit guarantee.
Is the online STL viewer the same as this repair page?
No. /online-stl-viewer.html is inspect-only: orbit, section, wireframe, and a geometry inventory. Conservative repair, reconstructive repair, and downloads are on this URL, /stl-file-repair-online.html. The Spanish repair twin is /stl-fixer.html.
Does this job create a TrazaLab case?
No. This work does not attach the case to an account automatically. Odontogram, digital Rx, evidence, and laboratory send live in the TrazaLab case workflow. Use the handoff links on this page when you want that sequence.