Anterior 3-Unit Emax Dental Bridge Case: How We Rebuilt a Discolored Upper Front Smile

Why the patient wanted it done:

• She works in sales, talks to people all day, and does not want anything that looks like a crown with a dark line at the gum.
• She refused to touch #11 more than necessary ("don't grind down my good tooth").
• An implant on #10 was discussed with her periodontist two years ago and was taken off the table because of the bone profile and her preference not to have surgery.

So the brief, in plain English: three-unit anterior bridge, natural look, no visible gray at the margin, no implant, keep #11 as untouched as the design allows.

Why we wrote the parafunction field even though it was negative. Bruxism is the single biggest contraindication for a lithium disilicate bridge. Ivoclar's own product documentation lists severe parafunction as a contraindication for IPS e.max Press. If a case is going into emax, we want it on paper that we checked.

2. Dentist's Requirements

The prescription came in digital, with photos and a bite scan. The dentist is a US-based prosthodontist who sends us roughly a dozen cases a month. He writes a tight Rx — he knows exactly what he wants and he tells us up front. Below is the full list, grouped the way he grouped it.

A. Material, shade and build

B. Design parameters

C. Judgement calls (he wants us to answer before we cut)

He flagged three questions and asked us to come back with real answers, not boilerplate:

1. "Can the C3-ish stump on #9 be masked without opaquing the whole bridge?"
2. "Is 1.6 mm of interocclusal space enough for pressed emax across all three units, or do I need to open bite?"
3. "Is the current path of insertion clean, or does one of my preps need to come back for re-reduction?"

D. Clinical scope — his bench, not ours

He drew the line clearly on what he handles chairside, so we do not step on it:

• Isolation, retraction cord, bleeding control
• Cementation protocol — adhesive, HF etch + silane + dual-cure resin cement (the standard adhesive protocol for IPS e.max)
• Occlusal adjustment and chairside polishing at try-in
• Any contouring of the papilla area post-cementation

E. Delivery and documentation

• Digital design preview in the viewer before pressing — he will approve or ask for a change
• Connector cross-section number stated in writing in the preview (he reviews this before he approves)
• Shade photos of the finished bridge on model under daylight-balanced light, before shipping
• Return shipping label included in the package in case of remake

The three Group C questions are where this case got interesting. Two of them came back with a "no, but here is how we handle it" from our side. That conversation is section 3.

3. Our Production Process — How We Built This Bridge

This section covers the full path from case receipt to shipment, including the three design decisions we made before we cut, and the production chain we ran once the dentist approved them.

3.1 About the facility

Istar Dental Lab is a direct manufacturing facility, founded in 2012, with facilities in Shenzhen and Huizhou. Around 460 in-house staff across CAD (~100), milling (~70), implant (~80), ceramic and metal (~70), removable (~55), QC (~25), case coordination (~40), and sales / admin. We do not outsource cases to third-party labs. Every step on this bridge happened under our roof.

3.2 Three decisions we made before cutting

The dentist asked three questions in Group C. Here is what we answered, with the reasoning.

Decision 1 — The 1.6 mm interocclusal space

Pressed lithium disilicate reaches its published strength (around 400 MPa, generation and test method matter — see Ivoclar's e.max report) only when the restoration has the thickness the design calls for.

Our CAD design floor on an emax bridge is anterior minimum thickness 0.5–1.5 mm, posterior 0.8–2.0 mm, with connector cross-section 6–12 mm² anterior, 9–16 mm² posterior. That is the actual spec our CAD department uses on every emax case.

1.6 mm cleared the floor for the pontic body, but it was tight. If we sized the connector to the bottom of our range the bridge would be in spec on paper and have very little margin against normal loading. If we sized toward the middle we had to borrow space from the lingual.

We came back to the dentist: 1.6 mm is enough to proceed with pressed emax. Connector will be sized to 9.4 mm² (comfortably above the 6 mm² floor, below the 12 mm² ceiling). Extra height goes to the lingual, facial contour untouched. He signed off.

Decision 2 — The dark stump on #9

Stump on #9 read closer to C3 than A3 after the old post + core. Target shade on the bridge was A2 body, A1 incisal.

The appeal of an emax lithium disilicate bridge is translucency. Pick an opaque block for the whole bridge and the restoration looks flat; the dentist will reject at try-in. Pick a high-translucency block and the stump color telegraphs through #9 — the central reads gray next to the natural tooth on the other side.

We did not go to an opaque block. We used an MO ingot only on the #9 retainer internal, with a thin opaquer layer against the stump, and ran a translucent HT shade through the #10 pontic and #11 retainer. Layering decision, not block decision. Overall translucency stayed honest, masking happened only where it needed to.

(The general logic — translucency and strength trade against each other, thickness is the deciding factor — is laid out in the peer-reviewed literature on lithium disilicate ceramics.)

Decision 3 — The path of insertion

First design pass, our CAD team flagged a 7° discrepancy between the long axis of #9 and the long axis of #11. The axial walls were not parallel enough to seat the bridge along one path without binding.

Two options: ask for a re-prep on one abutment, or absorb it in the design. Re-prepping #11 was off the table — the patient's brief was "do not touch my good tooth more than you have to." So the fix went into CAD.

We tilted the common path of insertion toward the midline of the two abutments, taking the compensation evenly from the mesial of #9 and the distal of #11 inside the restoration intaglio. Block-out stayed inside tolerance for cementation. We flagged it in the preview with a short note: "Path adjusted, no re-prep needed, block-out within tolerance." He approved in the viewer.

Our rule on this: we compensate in the design. We do not change the prep. When the two options are "ask the dentist to re-prep" or "work within the design," we only ask for a re-prep when design cannot absorb it. In this case it could, and we said so.

3.3 The production chain, step by step

Once the dentist approved the three decisions, the bridge went through our standard in-house workflow. Here is the exact sequence for this unit, with the department and the working time:

Lab working time on this case: 3 working days. This is in line with our standard turnaround for a conventional crown and bridge case (2–3 working days from the day we receive a complete case; design approval wait time and client reply time are not counted — the clock pauses and restarts).

Two notes on QC. First, our QC team is a separate department from the technician who built the case — they sign off independently. Second, if a bridge does not pass QC (margin off, occlusion wrong, shade mismatch, connector under spec), we remake it automatically. We do not ship a borderline unit and ask the dentist to decide.

4. Try-In Feedback — What the Dentist and the Patient Said After Seating

We asked the dentist for a short write-up after try-in and again at the six-month recall. Below is a summary of what came back from both sides. These are concise paraphrases, not full transcripts.

From the dentist, at try-in and after cementation

• Seating: bridge seated along one path on the first try, no binding, no chairside adjustment of the intaglio needed
• Margins: closed cleanly on both abutments under magnification, no visible gap
• Occlusion: light centric contact across all three units, no interference in lateral or protrusive — only minor polishing after resin cement cleanup
• Pontic–tissue contact: light, no blanching at seating, no pressure point on the ridge
• Shade: read correctly against the adjacent natural #8 under both operatory light and the window daylight; incisal translucency matched; no gray showing through at the #9 margin
• Connector profile: round and polished as spec'd; floss threader passed cleanly
• Overall: cementation protocol ran as planned (HF etch + silane + dual-cure resin cement); no remake, no return

From the patient, after cementation and at the six-month recall

• Immediate reaction: happy with how the bridge looked compared to her natural tooth on the other side; said the color "did not look fake"
• Lip line: no visible margin line when smiling; no dark shadow at the gum
• Speech: no lisp, no air escape, adapted within the first day
• Eating: returned to normal diet within 48 hours; no sensitivity on #9 or #11
• Confidence: her words at the two-week check — "I stopped covering my mouth when I laugh"
• At six months: restoration in service, margins clean on probing, shade had not shifted; no chipping, no debond; patient reported no issues

We did not promise long-term outcomes, and we are not writing them here. What we can say is: at the six-month check, this emax dental bridge was doing exactly what the design brief asked for — on the dentist's chair, and in the patient's day-to-day life.

6. What This Case Tells You About Working With Us

If you prescribe an emax dental bridge on an anterior case with a discolored abutment, a tight interocclusal space, or a path-of-insertion problem, this is roughly how we will handle it:

• We will check your interocclusal space against our thickness floor before we start. If it clears, we will say so and tell you exactly how we are using the room. If it does not clear, we will tell you that too, and we will suggest the material that fits.
• We will size the connector to a value we can defend, inside our anterior 6–12 mm² / posterior 9–16 mm² range, and we will put the number in the design preview so you see it before approval.
• If the path of insertion needs attention, we will try to absorb it in design first, and only ask for a re-prep when we cannot.
• We will build shade with a layering decision, not a block decision, whenever a dark stump is in play. An opaque block is a last resort, not a default.
• QC is a separate department. A unit that does not pass gets remade, not re-quoted.
• Our standard turnaround on a conventional crown and bridge case is 2–3 working days of lab time, with the clock starting the day we receive a complete case.

If you want to send us a case, we only need three things to give you a real answer back on whether an emax bridge is the right choice: the digital scan (or physical model), a stump shade photo, and your target shade. We will come back with a yes, a no, or a "yes if you change one of these two things" — in writing.

Istar Dental Lab, in-house manufacturing in Shenzhen and Huizhou. Request a quote on your emax dental bridge case or arrange a factory visit or video inspection — both are available to all dental clinics, dentists, DSOs, and outsourcing labs we work with.

FAQ — This Case and Emax Bridges In General

Q1. Why pressed emax and not milled emax for an anterior bridge? Milled emax is also a valid choice. On this specific case the dentist asked for pressed because of the layering freedom and the surface quality he gets on anteriors. Both routes end up as lithium disilicate; the ingot form and the processing differ. Ivoclar documents both.

Q2. Would you have made this bridge in zirconia instead? On this case, no — the dentist and patient wanted the translucency that lithium disilicate gives you on an anterior. Zirconia would have been a stronger framework, but the shade match on #10 pontic against the natural #8 would have been harder to carry off without going to a layered zirconia, which brings its own chipping risk on the facing porcelain. The 1.6 mm space, the untouched #11, and the A1–A2 shade band all pointed to emax.

Q3. What is the span limit for an emax dental bridge? Three units, with the distal abutment no further back than the second premolar, and no cantilever design. This is from the IPS e.max Press clinical documentation. Longer spans, molars as the distal abutment, or cantilevers are not an emax indication — we will tell you to use zirconia on those.

Q4. What is the minimum interocclusal space you need for an emax bridge? Around 1.5 mm as a working figure. Below that, we go back to the dentist with options. On this case we had 1.6 mm and used it carefully; a case with 1.2 mm would get a different recommendation.

Q5. How do you handle a dark or metal post abutment on an emax bridge case? Shade photo of the stump, every time. We decide block type and whether to layer or opaque locally based on that photo. Without a stump shade photo we do not quote the shade.

Q6. Can you remake a failed emax bridge? A connector fracture on a lithium disilicate bridge cannot be repaired in the mouth — the bridge is remade. A debonded unit that is still intact can usually be cleaned, re-etched and silanated, and recemented, after the dentist checks why it came loose. The decision between repair, recement, and remake comes down to where the failure is.

Q7. What is your lab turnaround for an emax dental bridge? 2–3 working days of actual lab time for a conventional case, in line with our standard crown and bridge turnaround. Design approval wait, missing information, and client reply time are not counted toward that number — the clock pauses and restarts when the case is complete again. Shipping is a separate step on top.

Q8. Do you auto-remake if QC fails? Yes. If a unit does not pass internal QC — margin, occlusion, connector cross-section, shade — the unit is remade automatically. We do not ship a borderline unit and ask the dentist to decide.