Complete dentures.
A complete denture succeeds or fails on its records. Each stage produces the information the next depends on, and the Rx form is set up to prescribe them one at a time.
The sequence
A primary impression in stock trays produces the cast from which a custom tray is made. The custom tray, border moulded, allows a definitive impression that captures the functional periphery rather than an arbitrary one.
Bite blocks then establish the vertical dimension, the horizontal jaw relation, the occlusal plane and the lip support. A set-up try-in follows, where tooth position, appearance and phonetics are assessed with the patient before anything is processed. Then finish.
Tick the stage you are prescribing under Procedure. Prescribing the whole sequence at once removes the verification each stage exists to provide.
The definitive impression does the most work
Retention and stability come from an accurate fit against the denture-bearing area and a periphery that sits within the functional sulcus — extended enough to seal, not so far that muscle activity displaces the denture.
Border moulding a custom tray is what achieves that, and it is the step most often compressed. A definitive impression taken in a stock tray records an arbitrary periphery, and the resulting denture is retained by whatever accident of anatomy happens to help.
For the maxilla, the posterior palatal seal area needs identifying. Mark it or describe it — the laboratory can place a post dam on the cast, but where it goes is a clinical judgement about tissue displaceability.
Jaw relation is the stage with the most consequences
An error here propagates through everything afterwards and is not correctable without remaking. Vertical dimension too great produces discomfort, clicking and difficulty closing; too little produces an aged appearance, angular cheilitis and reduced function.
The horizontal relation has to be a reproducible retruded position rather than a posture the patient happens to adopt on the day. Where it is not reproducible, say so — it changes how the case is mounted.
Record the occlusal plane and the midline on the bite blocks, and note the lip support you want. Those marks are the ceramist's reference for tooth position.
Tooth selection
The Rx form asks for Shade and Mould under Teeth, and both matter more than they are usually given credit for.
Mould governs the size and form of the anterior teeth, which is what makes a denture read as belonging to the patient rather than as a generic set. Age, facial form, sex and the patient's own preference all bear on it — and a pre-extraction photograph is the single most useful reference if one exists.
Shade should be assessed against the patient's complexion and age rather than chosen at the lightest available. Patients frequently request very light teeth and are dissatisfied with the result; that conversation belongs before the try-in.
Use the try-in properly
The set-up try-in is the last point at which tooth position, appearance, phonetics and occlusal scheme can all be changed easily. Assess speech, look at the smile line and the midline, check lip support, and involve the patient directly.
A patient who has approved a try-in accepts the finished denture far more readily than one presented with a processed result. Photograph the approved try-in.
If changes are needed, describe them specifically — teeth too long, midline off to the left, more lip support required — rather than returning it with a general note.
What to put on the prescription
Tick Complete Denture under Type of Denture and the stage under Procedure. Give the teeth shade and mould, and note anything unusual about the ridges, the jaw relation or the patient's expectations.
If the patient has an existing denture they like or dislike, send it or photograph it. Knowing what to reproduce or avoid is worth more than any written description.
More in Removable Prosthetics
Send a case
Digital scans and conventional impressions are both accepted. Cases move by UPS and Purolator, and Fairmont works with practices throughout British Columbia and across Canada.