I HAVE been motivated to reiterate this topic because of what I observed in a patient’s mouth a few days ago. 
Simply put, a patient had a denture installed some time ago by a ‘quack’ and came to me with the complaint of “soreness of the gum.”  Examination revealed dysplasia, which is a pre-cancerous condition.
Although more than 50 per cent of all Guyanese use some form of dental prosthesis (dentures), widespread ignorance with respect to the implications still exists. One reason for this is a major part being fabricated illegally by ‘quacks’, who are in no position to educate the users.
In fact, patients are often led to believe, or they assume among other things, that pain and discomfort must preceed the so-called ‘bedding-in’ of a new denture. Quite apart, too, they cannot accept the limitations inherent in the use of ‘false-teeth’ and so relatively minor difficulties are perceived to be major problems.
Frequently, the dentist faces a virtually impossible task when a patient expects an ideal denture, despite presenting a mouth replete with unfavourable characteristics.
The mouth is a dynamic environment. When a tooth is extracted, the adjacent ones migrate to close the gap, or may move apart. When three or more contiguous teeth are lost, the alveolar ridge (where the teeth were growing) progressively absorbs. The absorption of this bony ridge in totally edentulous (without any teeth) persons is the most formidable problem in prosthodontics, since it is this very ridge which holds the denture in place.
In order to overcome difficulties with comfort, retention, good looks and proper function, there must be an uncompromising approach, based on established procedures. The primary impression is taken of the entire job in question, and a plastic model is made immediately. A secondary impression may be obtained with a tray made from the primary impression’s model.
The next stage is to take the vertical dimension with the length and position of the artificial teeth. The so-called ‘trial’ is next. Here, an exact replica of the denture is developed with wax gums and palate. The patient is shown in a mirror how he would look with his new denture, at which point any desired modification can be made to his or her satisfaction.
The final product is constructed from a mould of the trial denture. The patient should be advised as to what to expect, based on his individual circumstance. Usually, the installation period lasts about two weeks, during which time the denture may be selectively filed to ameliorate comfort. Consistent chafing of the gums or mucosa by an ill-fitting denture could eventually result in cancer.
Sometimes a denture may not fit snugly, and the patient may believe that it is slack. In theory, this is impossible because it was fabricated on a faithful impression. In most cases, the reason could be a flat or absorbed ridge, too high flange (rim) that would cause ejection by the frenulum or buccinator muscle, thick denture (too heavy to stay up on the upper jaw), or xerostomia (insufficient saliva for adhesion).
Other causes include improper impression (too much air-space between the material and the tissue), and uneducated, neuro-muscular apparatus (mouth) unaccustomed to the denture. Patients should bear in mind that the same manner a person who has lost both legs cannot expect to play football, similarly a person who has lost all of his teeth cannot realistically expect to derive the advantages as if he possessed natural teeth. Denture adhesive in the form of a cream or powder serves to maintain a ‘slack’ denture in place.