How A Dentist Does A Denture Try-in?
When constructing a full or a complesite denture for a patient, a dentist needs to go through various stages of construction that is common to all denture fabrication processes. The minimum number of visits required is four but that can increase to 8 or more. The first stage is called the impression stage. This is when your dentist will record the details and the shape of your mouth. The more accurate this is, the more accurate the final denture will fit in your mouth. The impression of your mouth is sent to the dental technician who creates a negative of this and produces something called a stone study cast. The technician will use this stone study cast in order to fabricate your new dentures.
The second stage in fabrication of full or complete dentures is called the bite stage. The dental technician constructs wax bite rims on the model that has been produced in the first stage. You, as a dentist will then place these wax bite rims in the patient's mouth and carry out various adjustments. The various adjustments will represent how the patient will bite when they have the new final permanent dentures. These various adjustments will also include the length of the teeth, the amount of teeth that the patient will ultimately show, the forward protrusion of the teeth, the midline and importantly the curve of the smile line. There are two curves which are very important and these are known as the curve of Manson and the curve of Spee. The wax bite pattern is sent back to the technician again and he will then construct a denture try in. The denture try-in stage is really like the final stage before constructing the permanent denture and it is a final opportunity to make any adjustments. There are many factors to check at this stage. Here is a list of the important practice points to check at this stage. Firstly, let's look at the appearance of the teeth and positioning which at this stage are set in wax. Most importantly, is the shade of the teeth which correlates and is correct as to what a patient would like. It is always important to ask the patient for the opinion because as a dentist you may think that the teeth may be too light in colour but the patient actually prefers this colour. We also need to take a careful look at the size and shape of the teeth. Does the size of the teeth fit in with the patient's facial size and features? Next the actual detail of the teeth needs to be looked at. This is largely governed by the patient's finances. On the NHS, you can't really expect too much other than basic teeth with little fine detail. Using teeth on a private basis, you have a lot more choice and variety and control over how realistic you want the final teeth to look like. On a private basis, the technician has a larger list of moulds that he can use and many of these are so good that they are almost indistinguishable from normal healthy natural teeth. The following aspects include that you need to look at the angulation of the teeth. Are the teeth too proclined or are they too retroclined? Once again if there are errors at this stage, they can easily be corrected. The length of the teeth is important because if they are too long, the patient will look like a horse and in addition the teeth will encroach excessively on the patient’s lower lip.
Finally, we mentioned the curve of Manson and the curve of Spee. In general and as a general guide the curve could mimic the curve of the lower lip with the teeth corresponding to the midline and be vertical and not at a slant. Once the denture try-in has been finalised, then you can go ahead and instruct the dental technician to construct the final permanent denture which you will then fit at the following visit. Although the minimum usual number of dental visits to make a denture is 4, often additional visits are required when taking secondary impressions using special trays, or when an additional try-in is required or when a process has to be repeated. The photo diagram above is actually a photograph of a denture try-in that we recently did for a patient. We actually replicated what her natural teeth looked like. Unsurprisingly, when she received her final denture, she received many compliments and even when she spoke to somebody that she had not seen for a long time, they would be totally surprised to hear that these were not her own teeth but they were in fact denture teeth because they just looked so natural and realistic.