1 · The patient on the slip
A woman in her early thirties went over the handlebars on a weekend ride. The impact split her upper lip and bent #8 forward. The emergency office took a periapical, repositioned the tooth, and splinted it to #7 and #9 for two weeks. Six weeks later a different clinic finished the root canal through the lingual access. By the time the file reached our bench, the splint was off, the gingiva around #8 had settled, and the tooth was back in function.
What she wanted was the part a lab does not usually hear directly, so we quote it from the clinician's intake note:
"The patient is sensitive about anyone touching the front of this tooth. She has looked up veneers and crowns and does not want either. She is asking whether the hole on the back can be closed without changing anything you can see from the front."
That one sentence shaped every design choice downstream. It is also why this case had to be an inlay, or it had to be nothing — a facial preparation would have been a different conversation, and that conversation had already been had.
1.1 · Clinical picture that reached the bench
Patient profile (anonymized)
Field | Entry |
|---|---|
Age / sex | Early 30s, female |
General health | Fit, non‑smoker, no systemic conditions on file |
Dental history | No prior restorations on #7–#10. Hygiene good. No reported bruxism. |
Chief concern she voiced | Not aesthetics in the usual sense — fear of over‑preparation on an undamaged labial surface |
Tooth: 11 / #8 (FDI / Universal)
Field | Entry |
|---|---|
Event | Blunt trauma, 8 weeks before case receipt. Luxation reduced and splinted on day 0. |
Pulp | Non‑vital. Root canal completed six weeks ago at a second clinic. |
Access | Lingual, roughly 3.1 mm mesio‑distal × 3.4 mm inciso‑cervical, provisional composite in place. |
Crown | Intact. No visible craze line extending beyond the access boundary. |
Walls | Both proximal walls full height. Incisal edge preserved, no chipping. |
Facial surface | Untouched. Enamel continuous. |
Caries | None on bitewings and periapical. |
Shade of #8 (current) | A3 at the gingival third, drifting to A2.5 at the incisal — half a step greyer than #9 under direct light, closer under soft light. |
Shade of #9 (reference neighbour) | A2, high translucency at the incisal, no discoloration. |
Stump shade through the access | A3 at the axial floor, A2.5 on surrounding dentin. |
Occlusion | Class I, canine‑guided. Palatal of #8 carries one static contact 0.8 mm cervical to the mesio‑palatal line angle of the planned restoration outline. |
Protrusive | Light contact on the palatal cingulum of #8 and #9 during protrusion. |
Habits | No night guard. No nail biting, no ice chewing, no instrument use on file. |
What was sent to us
Item | Format |
|---|---|
Full‑arch digital impression | STL, maxillary and mandibular |
Bite registration | Digital, intercuspal + light protrusive |
Periapical of #8 | For root fill reference and crack screening |
Shade photographs | Natural tooth + A2 tab, and prepared tooth + A3 tab, both under daylight‑balanced LED |
Intraoral photo | Lingual view with provisional in place; labial view showing #7–#10 |
Clinician's note | The quoted paragraph above, plus the slip in §2 |
1.2 · Three constraints that defined the case
Reading the file end to end, three constraints sat in direct tension:
- Facial surface stays untouched. Patient's hard line, dentist agreed.
- Colour matches #9 under natural light. With a substrate already a shade greyer than #9, the ceramic has to carry the correction, not the tooth.
- Margin out of occlusal load. Anterior guidance passes through the palatal surface in protrusion, exactly where this restoration lives.
Lithium disilicate at roughly 1.0–1.5 mm in a small anterior intracoronal section is where the three can all land. Below that, strength drops faster than optics; above it, the tooth pays for the colour. We ran the budget at design and brought the numbers back to the dentist before anyone cut anything.
2 · What the dentist asked us to make
The slip was short, and good — the clinician had done her side of the work:
Material: E.max (lithium disilicate), high translucency. Design: True intracoronal inlay, palatal only. Do not extend onto the facial surface. Do not touch the incisal edge. Shade: Match #9 under natural light. Account for a slightly grey stump; internal bleaching is planned later, so lean toward value, not high‑chroma. Minimum thickness at the isthmus: 1.2 mm. Margin: 90° butt joint, supragingival throughout. No bevel. Occlusion: No contact of the restoration margin in protrusion. Verify against the digital bite. Approval: Send the CAD design before milling. Hold the case for sign‑off. Delivery: Standard. Clinical seat scheduled 10 days from today.
Three asks we re‑read before design:
- Preserve the tooth. No facial reduction, no incisal involvement.
- Hit the aesthetic target. Match #9 under natural light with a stump already half a step darker.
- Keep the margin out of load. Move the restoration outline, not the tooth, to clear the protrusive mark.
3 · How we met those requirements
Nine stations under one roof. For this case the stations that mattered most were intake, CAD, shade, and QC.
3.1 · Intake: can the four conditions hold?
Our CAD designer opened the STL before reading the slip in full. The question at this stage was whether a bonded ceramic insert could actually be made on this tooth.
Condition | What we checked | What we found |
|---|---|---|
Ceramic thickness ≥ 1.0–1.5 mm | Measured available depth at the deepest point of the access and across the isthmus | 1.4 mm clear at the deepest, 1.2 mm at the narrowest. In the window for E.max. |
Enamel bonding at the margins | Traced the cavosurface against the enamel‑dentin boundary from the intraoral photos | Cavosurface sat in enamel on all four sides — the main reason this case could be an inlay at all. Enamel‑bonded ceramic survives better than ceramic bonded to dentin or old composite. |
Path of insertion | Rotated the scan palatal, mesial, distal | Clean path from the palatal direction. No residual undercut once we blocked out digitally. |
Contact pattern | Overlaid the digital bite and the protrusive trace on the planned outline | One static contact at 0.8 mm from the mesio‑palatal line angle. Flagged for design. |
A short reply went back to the dentist before anything was drawn: all four conditions hold; we will move the restoration outline 0.3 mm lingual at the mesio‑palatal corner to clear the protrusive mark. Written approval returned the same morning. The exchange took ten minutes.
3.2 · CAD design and approval before cutting the block
Design parameters locked in:
- 90° butt joint margin throughout — the preferred form for bonded ceramic, not a bevel.
- All internal line angles rounded, no sharp axio‑pulpal transitions.
- Isthmus held at 1.2 mm minimum, verified point‑by‑point on the digital thickness map.
- Single path of insertion from the palatal aspect. Undercuts blocked out in software, not by removing more tooth.
- Mesial proximal contact with #7 preserved at original tightness. Contact point placed 2.0 mm below the marginal ridge of #7.
- Outline moved 0.3 mm lingual at the mesio‑palatal corner, cleared the protrusive mark.
The dentist received two screenshots before milling: a thickness overlay, and a protrusive‑trace overlay against the finished outline. She signed off in writing. The case held one working day for that approval; it is a trade we build into the schedule for anterior work.
3.3 · Milling, firing, finishing
Milled from a lithium‑disilicate block in the blue, partially‑crystallized state, then fired to final strength on an insulating support rack placed to keep the thin isthmus unloaded through the thermal cycle. Furnace curve logged against case number. QC under a dedicated inspection lamp before anything else: edges checked for chipping, surface for cracks, isthmus against the digital thickness map. If anything is off, the piece does not advance.
3.4 · Shade — the step that decided the result
For a single anterior tooth, the shade is not a letter on the slip. It is a composite of three inputs:
Input | What it carries | Source |
|---|---|---|
Natural‑tooth photo with VITA tab in frame | Target hue, chroma, and translucency of #9 | Clinic |
Stump photo with tab against the prepared tooth | The substrate the ceramic has to sit on | Clinic |
Bleaching plan | Whether to lean toward value today or anticipate a lighter stump later | Slip |
Her stump read A3 at the axial floor, A2.5 on surrounding dentin; the target neighbour read A2 under daylight. Three ceramic bands were layered:
- Cervical third — slightly chromatic, to carry the stump without a thick opaquer layer.
- Mid band — the colour transition, aligned with the equator of the natural tooth.
- Incisal third — translucent, with a thin violet‑grey halo that echoes the enamel edge of #9.
Internal bleaching was planned later. We biased the overall value one half‑step higher than #9's current reading. If #8 is bleached after the inlay seats, the two teeth meet in the middle; if bleaching is delayed, the inlay stays close enough under soft light to pass.
3.5 · Pre‑ship QC and packaging
Three checks before the piece left:
- Proximal contact — floss resistance equivalent to the opposite side, no shred, no snap‑through.
- Margin continuity — no gap readable at the cavosurface line under the inspection lamp.
- Occlusion — no high spot on the protrusive trace against the digital opposing arch.
Packed in a foam‑lined box, labelled by case number. Firing log, material lot number, design screenshots, and the shade recipe folded in on paper. The box is sized so the piece does not touch the walls — thin anterior work breaks in transit when it is not supported.
Turnaround for this case, scan to shipment: three bench days for the fabrication, plus one working day for the CAD approval the dentist asked for.
4 · What came back from the chair — try‑in and seat
What follows is the record of this case as it returned to the lab after seat. It is chairside observation and clinical measurement, logged on the case file and the sixty‑day follow‑up form.
4.1 · At try‑in (before cementation)
Check | What the clinician recorded |
|---|---|
Seat | Full seat on first attempt from the palatal direction. No rocking under finger pressure. |
Marginal fit | Continuous at all four cavosurface edges under 2.5× loupes. Explorer caught no step at the mesio‑palatal corner, which is where we had moved the outline. |
Proximal contact | Floss shred‑free; passage resistance matched the contralateral #9–#10 contact. |
Shade against #9 | Match within the margin of error of the shade photo at try‑in. Value slightly higher than #9 as planned for the future bleaching window. |
Occlusion | No contact on the restoration margin in centric or protrusion. Verified with articulating ribbon; no mark on the restoration outline, only on the natural palatal cingulum where it belonged. |
Adjustment on the piece | None required chairside. No reduction, no polish‑back. |
4.2 · Clinician's note returned to the lab after cementation
"Seated as drawn. No adjustment on the piece, no adjustment on #8. Margin is where I asked for it, including the corner you moved. Shade reads a half step higher than #9 at the chair, which is what we agreed; patient's bleaching tray goes in next week. One remark — the inspection‑lamp photo you sent in the box let me match the margin area under the microscope faster than if I had been reading it cold. Keep doing that."
4.3 · What was recorded in the case file
- Chairside adjustment on the restoration: 0.
- Chairside adjustment on the tooth: 0.
- Rebonding or reseat on the same visit: no.
- Marginal gap recorded under the clinician's microscope: not visually detectable at 10×.
- Protrusive contact on the restoration outline: none.
4.4 · Sixty‑day follow‑up (standard window)
The follow‑up form the clinic returns at day 60 is a short, boxed questionnaire. For this case the boxes came back as:
Follow‑up field | Return |
|---|---|
Post‑operative sensitivity at week 1 | None reported |
Post‑operative sensitivity at week 4 | None reported |
Patient's own comment, if offered | "I keep forgetting which one it was." (recorded by the clinician in the free‑text field) |
Food impaction at the mesial contact | None |
Marginal integrity under microscope at day 60 | Intact; no staining line |
Shade drift vs #9 | None detectable in soft light; half‑step offset in direct light as expected before bleaching |
Chip, crack, or debonding | None |
Internal bleaching performed? | Yes, two sessions at weeks 3 and 5 |
Shade match after bleaching | Clinician's note: "They sit as a pair now." |
Nothing on this page is a prediction. Over a longer horizon, the published data on bonded ceramic indirect restorations supports a five‑to‑ten year planning window for a well‑selected, enamel‑bonded case, and the anterior‑specific evidence base is thin as the published review of ceramic partial restorations in anterior teeth sets out. This is a planning horizon, not a promise.
4.5 · What we would do differently next time
Noted on the internal case review:
- Keep the inspection‑lamp margin photo in the package by default. The clinician explicitly asked for it. It takes two minutes at QC and saves time at the chair.
- Flag the bleaching window on every anterior case with a non‑vital neighbour. For this case the clinician raised it; next time we raise it first.
- Document the 0.3 mm outline move on the design screenshot. We described it in the message. Next time we annotate it on the image itself, so the clinician's microscope reads it faster at seat.
5 · What this case tells a dentist sending us the next one
Four short decisions, before anything is prepared, that would make the next front tooth inlay easier to land in one visit:
Decide at the slip stage | Why it matters |
|---|---|
Is this really an inlay, or is it a fragment, a partial veneer, or a crown? | Different preparation, different ceramic thickness, different conversation. If the incisal is involved or the facial is partly in the design, say so and we route it. |
Can the margin sit in enamel on at least three sides? | E.max is the usual choice, and its advantage is largest when the bond is to enamel. If most of the cavosurface is dentin, we may recommend a design that does not depend on it. |
Is there any contact on the restoration outline in centric or protrusion? | A ceramic margin in a load path chips. If moving the outline a fraction clears the mark, say so on the slip and we draw it that way. |
Is bleaching planned before, during, or after the restoration? | Shade biased wrongly here is the single most common anterior "miss". A line on the slip is enough. |
Six fields on the file turn the first reply into a design decision instead of a list of questions:
- Full‑arch STL with the opposing arch and the bite registration.
- A natural‑tooth photo with a VITA tab in frame.
- A stump‑shade photo with a tab against the prepared tooth.
- Desired translucency band (HT, LT) and planned cement shade.
- Preparation intent on the slip — margin form, extensions, do‑not‑touch zones.
- A line on the occlusion — guidance pattern, protrusive marks, bruxism, night guard.
Send the scan and the two photos, and the first reply will be a yes with a design decision, a no with the reason, or a redirect to a fragment, a partial veneer, or a partial crown — whichever answer the tooth actually supports.