Learn About Dental Implant Dentures
A dental implant over-denture connects to cylinder-like configurations (called implants) that have been surgically implanted into the jawbone.
The dental implant denture appears like a traditional prosthesis. However, the part of the denture overlying the dental implants is modified to retain various semi-rigid attachments that receive dental implant extensions projecting above the gum. This arrangement helps keep a denture securely in place while eating, speaking, and during other oral activities, but still allows easy self-removal of the denture for cleaning purposes.
There are two phases to this process. The first is a surgical phase consisting of two stages, and the second is a prosthetic phase (making the implant denture).
The Surgical Phase of Dental Implants
1. Surgical Implant Insertion Stage
- Dental implants are completely inserted into precise preparations in the jawbone. While there are various dental implant configurations, they are essentially cylindrical in shape and made of pure titanium metal. After dental implants are inserted into the jawbone, gum tissue over the dental implant is closed with sutures, in most cases.
- While a minimum of two dental implants may be inserted for an acceptable outcome, a person may plan to receive three or more, depending upon individual needs and anatomical limitations. More dental implants will give additional support and retention to the dental implant denture.
2. Healing and Surgical Exposure Stage
- During healing, an existing or temporary denture may continue to be worn after adjustments have been made to adapt it to the surgical site. If the existing denture cannot be altered sufficiently, a provisional prosthesis should be fabricated.
- Dental implants are left undisturbed beneath gum tissue for at least several months as determined by the dentist. During this time, bone reorganizes and grows around the dental implant surface, anchoring it securely into the jaw (this is called osseointegration).
- At the end of the healing stage, the top of the dental implant is exposed by removing gum tissue directly over it. An extension that is then screwed into the exposed dental implant projects slightly above the gum tissue.
- After adjustments, an existing denture can be worn over an dental implant denture extension while the gum heals. However, the denture must be reshaped to conform to surgical site contours in order to avoid unnecessary pressure areas on the newly inserted extensions and the surgical area.
The Prosthetic Phase (Making the Dental Implant Dentures)
- A precision superstructure is fabricated and is screwed into the dental implant extensions. This superstructure may have various interface configurations, ranging from interconnecting metal bars to specially shaped singular extensions.
- A dental implant denture is fabricated with special provisions on the inside surface to receive various types of attachments (interlocks). Depending on the attachment, they interact in various ways with the superstructure. For example, a metal or plastic attachment may clip onto metal superstructure bars, a nylon receptacle may receive a specially configured dental implant extension, etc.
- The attachment/superstructure configuration helps to securely maintain a denture while eating and speaking, and still allows a person to comfortably and easily remove the prosthesis for cleaning purposes.
Essential Dental Implant Dentures Maintenance Needs
As might be expected, exemplary oral hygiene is essential to help prevent the development of disease around dental implant dentures that could cause their failure.
Implants, superstructure, attachments, and the over-denture must be checked and professionally maintained by a licensed dentist on a regular basis. Attachments often need periodic adjustment or replacement due to wear.
While the dental implant over-denture approach is complex and expensive, the value received by an individual usually far exceeds monetary considerations.
How Long Will Dental Implant Dentures Last?
Dental implant dentures may last for a lifetime (current reports show many dental implants lasting 20 years) or deteriorate in a few years. Many factors are involved that reduce the life expectancy of dental implants, such as oral hygiene, general health, habits such as smoking, grinding, etc. The superstructure or dental implant extensions may need to be replaced after five years. Depending on the dental implant system used, some parts may need to be replaced annually, or sooner, because of wear or deterioration. These time frames are generalities. The dental profession continues to strive for long-term durability of dental implant dentures.
by Joseph J. Massad, D.D.S.
+Jim Du Molin is a leading Internet search expert helping individuals and families connect with the right dentist in their area. Visit his author page.
When Should a Denture Be Replaced?
There is no specifically agreed-upon chronological answer by dentists to "When should a denture be replaced?" There are instances where dentures have been replaced after 1 year or less, and on the opposite side of the spectrum, there are people who have worn the same dentures for 25 or more years. These ranges obviously are extremes.
However, on average, dentists seem to be replacing dentures somewhere between four to eight years. This would seem to imply that the average denture fabricated from contemporary biomaterials will wear out and deteriorate within that time and/or the average denture patient's jaws have changed so much that a new denture must be redone.
Each individual's denture needs are different. There are some factors that a licensed dentist takes into consideration when evaluating the need to replace dentures.
Denture Longevity Considerations
Lost vertical dimension:
The proper linear distance relationship between the upper and lower jaws is called vertical dimension. This is unique for each individual.
As one's jaw changes and the ridges upon which dentures rest shrink, a denture becomes loose and vertical dimension begins to change (the vertical dimension is said to be lost by a certain linear measurement unit such as millimeters). Additional plastic (acrylic resin) is added to the inside of a loosening denture (called relining a denture) to stabilize it by reducing looseness caused from jaw shrinkage. However, relining does not restore vertical dimension in an accurate way.
The current position held by most dentists is that when vertical dimension has been lost by three millimeters or more, a new denture should be fabricated in order to restore vertical dimension and maintain functional health.
There are individuals who have worn the same denture for extended periods with considerable loss of vertical dimension over time. Since vertical dimension loss is a slow, but nevertheless progressive, process, they have gradually adapted to a continually increasing closed bite position. These individuals often have a sunken facial appearance and usually appear much older than their chronological age.
Functioning with an abnormal vertical dimension may eventually result in alterations of the temporomandibular joints (TMJ, the jaw joint located in front of the ears). This can lead to significant pain and difficulty with effective eating and even the jaw motions involved with speech. It frequently becomes quite difficult, if not impossible, to restore such individual's proper vertical dimension and chewing efficiency by relining and repairing this older denture.
Tooth wear:
Aside from impaired ability to chew effectively, excess tooth wear will adversely affect esthetics and cause other problems associated with lost vertical dimension, as described above. While porcelain denture teeth will wear at a slower rate than plastic teeth, they nevertheless will wear and are more susceptible to chipping and cracking. Multiple cracked teeth will need to be replaced.
Deterioration: While the biomaterials used by dentists to fabricate dentures today are quite durable, they still deteriorate and exhibit dimensional change over time -- no longer fitting properly, even after relining.
Aging plastic looses its natural appearance and texture, and coloration fades, making dentures look quite artificial.
Deteriorating plastic also makes it easier for dentures to become excessively contaminated with microorganisms. This contributes to mouth irritation and bad taste, and socially unacceptable odors will develop that no amount of denture cleaning will seem to eliminate.
Keeping regular dental check-ups with your dentist so that one's dentures, soft tissues, and jawbone may be checked is essential to extending the life of a denture and maintaining oral health.
by Joseph J. Massad, D.D.S.
+Jim Du Molin is a leading Internet search expert helping individuals and families connect with the right dentist in their area. Visit his author page.