Learn About Conventional Over-Denture
A conventional over-denture rests over some healthy natural tooth roots. This approach was first reported in 1861. To understand this method, it is necessary to review some facts.
An Overview of Alveolar Ridge Dynamics
- Maintaining a denture on the jawbone ridge (called alveolar ridge) is essential to prevent it from becoming loose during eating, speaking, and other activities.
- Preserving the alveolar ridge facilitates denture stability.
- The body tends to conserve energy and nutrients by maintaining only structures with apparent immediate value. A typical example is the bulk reduction of a broken leg held immobile by a full-leg cast for a month or more.
- The body recognizes that the only one purpose for alveolar bone is to hold tooth roots.
- Alveolar bone no longer supporting a tooth root is removed, or literally dissolved away, by the body. This is called resorption, or simply shrinkage.
- Resorption progresses at varying rates in the same person at different times, and at different rates between different people. Resorption progresses rapidly within the first year of losing a tooth, after which time, the rate progresses at a slower pace.
From this overview, if the maximum amount of alveolar ridge is to be maintained, then preserving the maximum number of periodontally healthy tooth roots should achieve that end.
Preserving the Sensation of Having Teeth
Studies demonstrate that even though only roots are preserved, and a denture covers them, a patient still has sensory input sensations similar to that experienced with teeth, as opposed to individuals with conventional dentures and no preserved roots. Over-denture patients also appear to have a more natural perceived directional sense in their chewing activities. In other words, many patients relate that they still feel like they have teeth -- a positive comment.
Underlying Philosophy of the Conventional Over-Denture
If a patient's treatment plan to have a denture, and the roots of some remaining teeth are supported in healthy alveolar bone, then a conventional over-denture is a viable consideration.
However, only a licensed dentist can determine if a conventional over-denture is a suitable consideration for a certain person, after a comprehensive examination.
Some Characteristics of a Conventional Over-Denture
- Most of a tooth crown (that part of the tooth above the gums) is removed. This often necessitates root canal therapy if not already done.
- The remaining tooth, projecting above the gum, is rounded and usually covered with a similarly shaped artificial crown-like covering.
- Various configurations and extensions may be built onto some retained roots. In those cases, that portion of the denture overlying these configurations is modified to contain attachments that clip onto a framework or receive the individual extensions. In addition to preserving alveolar bone and sensory input, the denture is held securely in place, but may be comfortably and easily removed for cleaning.
Advantages of a Conventional Over-Denture
- Feels more like having teeth
- More retentive in many cases
- Helps reduce shrinkage of surrounding bone
- Reduces pressure to portions of the alveolar ridge
- Positive psychological advantage of still having teeth
Disadvantages of a Conventional Over-Denture
- Scrupulous oral hygiene is essential in order to prevent decay and gum disease
- The over-denture may feel bulkier than a conventional denture
- Frequent maintenance examinations are necessary
- Generally, this is a more expensive approach than a conventional denture
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.
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.
