Metal Based Denture vs Plastic - Which is Best for You?
A metal-based denture is one in which a portion of the denture body is made of a substantial metal casting rather than all plastic (acrylic resin). This procedure is usually done on the lower denture.
There are two types of metal-based dentures.
Standard metal-based denture
The metal base portion of the denture is in direct contact with underlying supporting tissues.
The base is fabricated from a special medical grade alloy that is hypoallergenic and very biocompatible with tissues. Generally, tissues in contact with this type of material are very healthy in appearance.
Modified metal-based denture
The metal base portion of the denture is not in direct contact with underlying supporting tissues. A soft or hard plastic liner may be interposed between the metal and supporting tissues.
A soft liner is generally preferred to hard plastic since it is more comfortable to wear; however, the soft liner usually should be replaced on an annual basis.
The Rationale for a Metal-Based Denture
Facilitates the avoidance of disruptive forces
Sometimes it is necessary to construct a very narrow denture in order to avoid any structures that would loosen the prosthesis, such as muscles flexing, and so forth. In addition, necessary surgical procedures to reposition a muscle attachment (called a frenum) can sometimes be avoided with these narrow type dentures.
However, such narrow dentures are weak and tend to break quite easily when fabricated just from plastic. A metal base provides the needed strength to design a very narrow denture in order to follow the confines of a patient's lower resorbed alveolar ridge (the remaining bony ridge). In addition, the metal base provides long-term dimensional stability and strength that is not enjoyed with an all-plastic denture base.
Provides a more natural feeling
The added weight of the metal base provides a more natural perception for many patients. Many patients prefer the additional weight on the lower jaw.
A private study measured the actual weight of cadaver jaw ridges and teeth that would normally be lost after the extraction of teeth and associated natural shrinkage of the jawbones. It was found that the weight of these tissues closely approximated the weight of a metal base. Therefore, it is likely that the more natural feeling perceived by persons wearing metal-based dentures is probably real rather than imagined.
The additional weight of a metal base also contributes to lower denture stability by causing the denture to settle down onto a jaw ridge.
Advantages of Metal-Based Dentures
- Very biocompatible and hypoallergenic with healthy-appearing supporting tissues
- May include a soft liner
- Can be relined easily
- Provides added strength for easily broken narrow dentures
- Facilitates fabrication of stable narrow-based dentures that are designed to avoid contact with disrupting muscle forces
- Sometimes facilitates the avoidance of surgical procedures to reposition frenum
- Patients perceive a more natural feeling from the added weight
- Weight may contribute to additional denture stability
- Dimensionally very stable when compared to all-plastic-based dentures during fabrication and over time
Disadvantages of Metal-Based Dentures
- Generally difficult to reline standard metal-based dentures; modified metal-based dentures (described earlier above) are easier to reline
- More costly to fabricate
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.