Muco-Dynamic — An Impression Technique for Stable Dentures

by Albert DeLuca, RDT, DD

The dental profession is an exact science where often all possible techniques and materials must be explored in order to find solutions to different cases. This exploration often pays off and ensures patient satisfaction.

Muco-dynamic denture construction material is such a material that it provides the operator with the flexibility of procedure by allowing him or her to repeat the procedure until the patient is comfortable and satisfied with the actual end product.

An accurate reproduction of the impression will allow for a total stable denture that will take care of phonetics, function and esthetics.

This product was originally developed for patients where no other impression techniques had been successful. The material allows full neuromuscular activity and allows the muscles to be at their fullest comfort of functional mode.

Once this functional mode is achieved the impression can be stabilized to produce a very accurate reproduction model where the denture can be constructed (Figs. 1A & B).

Unlike the most materials on the market which restrict chemicals components to a set point of one to five minutes, the muco-dynamic can be worked until one is satisfied with comfort and fit.

Most impression materials are used in an open mouth technique and are held in place with the tray or the denture. However, by the time the material sets, we have an impression that retains the muscle structure in one given position. The muco-dynamic on the other hand is a close mouth impression technique that allows the patient the full freedom and range of movements (Fig. 2).

The material, once in place, can be left in the mouth for 5 – 10 minutes or until the patient is in total comfort with optimum functions, this results in optimum stability. When this is achieved, the patient can be given one to two glasses of iced cool water to freeze the material exactly to the impression position achieved.

The procedure for this technique is to use the custom tray or the pre-construction denture that the patient already has.

The operator can pre-plasticize the muco-dynamic material and apply it to the denture or to the pre custom tray (Fig. 3). The tray is then kept in a cool place.

The impression is accomplished in the following manner. The muco-dynamic is truly plasticized by placing the material in warm water between 110F to 115F. depending on the oral cavity. If the oral cavity is flabby tissue, the operator may want to increase the temperature to 120F. When dealing with a rigid ridge the temperature should be maintained between 110F to 112F. When using the moulding rods the water temperature should be between 100F to 105F.

The plasticized muco-dynamic is then applied to the clean, dry surface of the denture or custom tray to the peripheral roll. We can spread the material on the denture with a warm spatula or a wet gloved finger. The surface of the denture is shaped to a desired thickness of approximately 2 to 3mm. Then a liberal amount of Muco-dynamic (3-4mm) is also placed on the buccal surfaces, about half way between the borders and the neck of the teeth on the dentures, or to the side of the tray. The pre- moulded impression material is kept in a cool place for any given length of time or until the operator and the patient is ready to take the impression.

With the patient seated in an upright position to prevent the adhesion of the material to his oral cavity, the operator should coat the lips with one/500 pre-impression. A container of warm water is placed near the chair and once the material is plasticized to the desired consistency, the denture is seated in the mouth of the patient to make sure that it is in a comfortable position.

The patient is asked to occlude several times, swallow and go through muscle shaping movements. There are several movements that the patient is asked to perform: opening wide and yawning, sucking of the thumb, whistling, kissing and bringing their lower lip down as far as possible to the chin. These movements are necessary because they cause muscle moulding movements. When the denture is in proper position and the occlusion is satisfactory the material is hardened by allowing the patient to hold ice water in the mouth. Two cups of ice water taken in mouthfuls is usually sufficient. The patient may drink the water if he/she wishes. After the denture is removed, if there is excessive material it must be cut off with a sharp blade. Where necessary, muco-dynamic softened material can be applied with a warm spatula. The new added material should be tempered under a low flame or softened with warm water. The denture is then reseated in the mouth and the impression is completed.

The flexibility, the ability to add, to remove or repeat the procedure as many times as possible and ensure patient satisfaction, is what makes this product ideal. In the end, everyone involved will be more than satisfied with the result.

Albert DeLuca is president of DeLuca Dental Laboratories.

Oral Health welcomes this original article.