A pressure point on a removable prosthesis (such as a complete or partial denture) is irritation, often appearing as a painful red spot or ulcer. This discomfort occurs when the force distributed by the prosthesis is not spread evenly across the supporting tissues but is instead concentrated on a small, specific region. The high-pressure load compresses the gum tissue against the underlying bone, disrupting blood flow and causing inflammation. Understanding the root cause of this concentrated force is the first step toward effective treatment.
Causes Related to Initial Prosthesis Fit
Pressure points appearing shortly after a new prosthesis is delivered are due to structural imperfections or errors made during fabrication. The acrylic base may contain small, unseen nodules or spicules of resin on the intaglio surface (the part resting against the gums). These hard bumps act as miniature pressure points, creating localized friction and pain against the mucosa.
Another common mechanical issue is the overextension of the denture borders or flanges. If the peripheral edges extend too far into the cheeks, lips, or muscle attachments, they can impinge on soft tissues during speaking or chewing. This constant rubbing leads to tissue laceration and pain, requiring the dentist to shorten and smooth the overextended edge. Inaccuracies stemming from a distorted initial impression can also result in a prosthesis that does not conform precisely to oral contours, causing the denture to rock or shift and preventing uniform force distribution.
Causes Related to Changes in Oral Anatomy
Even a perfectly fitting prosthesis will eventually create pressure points due to continuous, natural changes within the mouth. The most significant factor is alveolar bone resorption, which is the gradual shrinkage of the jaw ridge after teeth are lost. As the bone diminishes, the underlying foundation changes shape, making the denture progressively looser.
This loss of foundational support causes the prosthesis to settle unevenly and shift during function, leading to concentrated pressure spots. Systemic health conditions also contribute by altering the quality of oral tissues. For example, dry mouth (xerostomia) reduces the cushioning effect of saliva, which acts as a lubricant between the prosthesis and the soft tissues. Without this protective layer, friction and irritation increase.
Causes Related to Occlusion and Function
Pressure points can be generated by the act of chewing, even if the denture fits well at rest. This is often an issue of poor occlusal balance, which refers to how the upper and lower prosthetic teeth meet during function. If the teeth contact unevenly, it creates premature contacts where one part of the bite hits before the others.
This imbalance causes the entire denture to tilt or rock, distributing the chewing force to a small, high-pressure area instead of spreading it broadly. The resulting leverage causes localized tissue compression and pain. Parafunctional habits, such as clenching or grinding the teeth, dramatically increase the overall force applied to the prosthesis, which can overwhelm the soft tissues and create painful sore spots.
What to Do When a Pressure Point Occurs
The immediate action when a pressure point develops is to contact the dental professional for an adjustment appointment; attempting to modify the prosthesis at home is strongly discouraged. Filing or trimming the denture yourself can severely damage the appliance and create new, more severe pressure issues. For temporary relief, a warm salt water rinse or a mild topical anesthetic gel can soothe the irritated area.
Before the adjustment appointment, wear the denture for a few hours (ideally three to six) despite the discomfort. This period of wear allows the pressure point to create a clearly visible red mark on the gum tissue, corresponding to the exact spot on the prosthesis needing modification. The dentist can then use a special material like pressure-indicating paste to precisely locate the offending area and make the necessary adjustment, ensuring the fit is corrected without compromising stability.