As the teeth in your mouth begin to diminish and gaps begin to form, you begin to think about and research options for how to complete your dentition. The options will depend on how many teeth you have lost, where they are located in your mouth, your jaw structure, and your general health.
You have a preference for implants to complete lost teeth, but you may also want to fill the rest of your missing teeth with dentures with fewer implants. Or maybe you already wear dentures and want to improve the support and retention of your denture or modify an old denture with the possibilities offered by today's advanced dental techniques.
Whatever the reason, would you like us to offer you the “Overdenture” option to solve your problem in both cases? Let us state right away that overdenture application will offer you many prosthetic methods to complete your teeth.
Now, let's introduce the Overdenture application, provide you with information to help you make a decision, and address any questions you may have.
What is overdenture?
Overdentures are removable dentures designed to replace missing teeth for those who have lost more than one tooth for various reasons, and to be placed on a structure that reduces the load on the jawbone and provides better retention support, such as a natural tooth or an implant. They are also called implant-supported dentures or snap-on dentures.
Overdentures are defined as any removable dental prosthesis that covers and rests on one or more remaining natural teeth, the roots of natural teeth, or dental implants.
Who needs overdenture?
Patients who have lost teeth for various reasons may need overdenture. Overdenture can be used in the following cases:
- If there are congenitally defective teeth,
- If there are very worn teeth,
- If there is more than one tooth loss,
- If all teeth are lost,
- If chewing function is impaired,
- If there is a problem in the jaw bone due to long-term use of complete dentures,
- In case of discomfort with conventional prostheses,
- If it is desired to increase prosthesis retention,
- If there are aesthetic concerns.
What are the types of overdentures?
Of course, the dentist will decide whether you are suitable for overdenture application. For this purpose, after examining you, your dentist will see your intraoral structure and the condition of your jaw bones and teeth with various imaging methods. In addition, he/she will listen to your health history and determine whether you have chronic diseases, and if so, whether they are under control.
If your dentist decides that you are suitable for an overdenture, he or she will probably offer you two options. These options are the types of overdenture applications. So what are the types of overdentures?
The overdenture requires a solid abutment on which it is placed. The type of this abutment determines the type of overdenture. One of these is a prosthesis that is placed on the tooth or teeth in your mouth and called tooth-supported overdenture, and the other is a prosthesis that is placed on the implant and called implant-supported overdenture.
Tooth-supported overdenture:
The idea of leaving the tooth roots in the jaw and making a complete denture over them is more than 100 years old. A tooth-supported overdenture utilizes the natural teeth still present in your mouth. It is essential to have natural teeth. Even the presence of a few remaining teeth reduces alveolar bone resorption. It also preserves proprioception by protecting the desmodontal fibres, which are crucial for the dimensional and textural perception of food, thus increasing the patient's comfort during chewing.
In the tooth-supported overdenture method, the teeth or tooth roots remaining in the mouth are used as support, and the overdenture is placed on it.
How is a tooth-supported overdenture performed?
Firstly, the dentist decides which teeth will be used as support teeth. The support teeth are usually selected among the teeth with strong roots. Mostly canines or molars are preferred. If the support teeth need root canal treatment, root canal treatment is completed first. After the support teeth are selected, the following method is applied.
Tooth modification and reduction of supporting teeth:
To create more interdental space for the upper denture, the supporting teeth are contoured to a convex or dome-shaped surface by reducing their height. The tooth is reduced to a coronal height of 2 to 3 mm. This creates space for the tooth crown. The tooth is endodontically treated and filled with an amalgam or composite restoration.
Coping preparation
To increase the retention of the overdenture by covering the root part of the tooth, metal or porcelain crowns called copings are made on the roots of the support teeth. A coping is a cover for the exposed tooth surface.
Noncoping abutments
- Coronal height of 2 to 3 mm
- Convex or dome-shaped surface
- Require endodontic therapy
Short copings:
- 2‐3mm long
- RCT root canal therapy done.
- Copings are with a post
- Canals filled with GP (Gutta-percha is a material used to fill a tooth after a root canal procedure. Gutta-percha, a plastic substance from a Malaysian tree called a percha tree, is used as a permanent filling in root canals)
Long copings:
- 5‐8 mm long
- RCT is not a must
- Copings are long
Placing attachments
Attachments are the linchpins of an overdenture. Attachments, which are sensitive fasteners placed on the support teeth, ensure that the overdenture is firmly attached to the teeth, prevent the overdenture from slipping, and help to lock the overdenture when it is placed.
More retention can be gained by lengthening the post and the use of pins. It consists of two units: male and female. It is important for the clinician to know the connection system and the amount of mechanical load to be applied to the system.
The teeth that are to receive the attachments are prepared following the necessary adjustment period. A special diamond rotary instrument is used for this preparation.
Overdenture placement:
After the support teeth and attachments have been prepared, the overdenture can now be placed. The prosthesis comes complete according to the impression your dentist has taken from you. Your dentist will place the overdenture prosthesis and ensure that it fits snugly against the support teeth and attachments. Adjustments are then made if necessary.
What are the benefits of a tooth-supported overdenture?
Reduction in the rate of bone resorption:
When the teeth are retained, the integrity of the alveolar bone is preserved as it supports the supporting teeth, resulting in a reduction in the rate of bone resorption.
Better stability and retention of the overdenture:
It provides better overdenture support and stability due to the preservation of the remaining ridge contours near the detached teeth. The vertical walls of the remaining root provide additional stabilisation for the overdenture. The greater the vertical area covered by the root preparation, the greater the stabilisation provided. It provides better retention and greater masticatory efficiency, especially when mandibular overdenture retainer attachments are used.
Tactile discrimination:
Tactile discrimination is the ability to distinguish information received through the sense of touch. By protecting the teeth, the periodontal membrane is protected, which in turn protects the proprioceptive impulses. Thus, the chewing function is better felt.
Psychological benefits:
Patients experience psychological relief due to the restoration of chewing function and a more aesthetic appearance by completing missing teeth.
Fast and cheap treatment method:
Tooth-supported overdenture is a faster and cheaper treatment method compared to other methods, but there is an increase in cost and time when additional treatments are required.
The ability to convert:
Should complications occur with the existing overdenture supports, the teeth may be extracted, allowing for the conversion of the overdenture into a conventional complete denture.
What are the disadvantages of a tooth-supported overdenture?
- Additional treatment needs, coping construction, and special attachments may create additional costs.
- If the abutment teeth have large bone depressions in the area, especially in the front of the mandible, the prosthesis flange may not be able to fully open. This can affect both retention and the way the tooth looks.
- A thin acrylic denture base carries a risk of fracture over time.
- Especially in cases where the interocclusal space is limited, there may be difficulties in tooth alignment when the space required for abutment attachment systems is small.
- Patients may require scheduled recall appointments to reinforce their oral hygiene practices and apply topical fluoride to prevent caries and periodontal disease.
Implant-supported overdenture prostheses:
Implant-supported overdenture is a type in which implants placed in the jawbone are used as support. In other words, an implant is used as a support instead of a natural tooth. Dental implant overdentures are suitable for many people who have lost most or all of their teeth but have enough bone in their jaws to support the implants. The number of implants can be 2, 4, or 6
It has rapidly become widespread as a successful treatment method, especially for rehabilitating completely edentulous patients. Therefore, implant-supported overdenture is an effective treatment method that enhances the quality of life for edentulous patients. The implant-supported overdenture first requires a surgical procedure to place the implant into the bone.
Implant-supported overdenture types:
Fixed implant-supported overdenture:
The fixed implant-supported overdenture is locked in place with screws and cannot be removed. To remove the prosthesis, your dentist has to dismantle it. It is usually the most expensive option because it requires four dental implants and screws to support them.
Implant-supported overdenture with bar holder:
The bar retainer implant-supported overdenture has a bar attached to the implants that the prosthesis can clip onto. The bar allows you to remove and insert the overdenture as needed, while offering more security than a traditional denture. Most people only remove the overdenture to clean it or to sleep.
Implant-supported overdentures with ball retainers:
A ball-retained upper prosthesis uses ball-shaped supports to attach implants to the prosthesis. It provides greater stability and functionality than a conventional prosthesis. Ball retainers make it easier to clean and replace parts when needed.
How to perform an implant supported overdenture?
The application of an implant-supported overdenture prosthesis requires the following process.
Implant Placement:
It starts with the process of placing the number of implants determined by your dentist into your jawbone under local anesthesia. In this process, the normal implant placement procedure is applied.
Recovery Process:
The procedure initiated for the implant application continues, and the healing process begins for your implant to integrate with the jawbone. This process can take between 3 and 6 months, depending on the patient's condition.
Taking impressions:
Your dentist will take impressions of your implants and mouth and send the impressions to the laboratory to create the overdenture frame and artificial teeth.
Placement of the overdenture:
After the overdenture is made, your dentist will try it on and make any necessary changes.
Benefits of implant-supported overdenture
- Durability
- Ability to be replaced when needed.
- Stability and comfort
- Better chewing and speaking
- Protection of the jawbone
- Better aesthetic
- Psychological comfort
- Good oral hygiene
- Reduced irritation and sores.
Disadvantages of implant-supported overdenture
Implant-supported prostheses carry some risks, but these are usually minimal. Possible complications include:
- Risk of infection
- Nerve damage.
- Injury to your mouth.
- Sinus perforation (a hole in your sinus membrane).
Attachment systems used in overdenture applications
The retention system for fitting the overdenture to the supporting teeth consists of a mechanical device, a metal socket, and a tight-fitting part. It has two main elements. The first is the female part in the support tooth, and the second is the male part in the overdenture. The attachment systems used for the placement of the overdenture on the supporting teeth or implants are:
- Stud attachment
- Bar attachments
- Magnetic attachments
- Telescopic attachment
Stud attachments:
Stud attachments are one of the oldest attachments used in overdentures. This is a system that allows the overdenture to attach to the implants or teeth. It consists of two main parts. The first is a round, ball-shaped attachment that is placed on the implant or the supporting tooth, and the second is a slot in the interior of the prosthesis into which the ball attachment fits. The ball attachment is placed on the implant, and a socket is prepared on the inside of the overdenture. The overdenture with the socket is placed on the ball attachment. It is immovable and can be easily removed if necessary.
Ball attachment, Locaters, O-ring attachments, Extracoronal Resilient Attachment (ERA) attachments are very commonly used.
Bar attachment:
The overdenture is placed through a metal bar placed over the implants for support. It is a preferred method especially in cases of complete edentulism.
In the bar system, 2, 4, or 6 implants placed in the jawbone constitute the basic support on which the bar will be fixed. The bar provides the surface on which the overdenture will hold. On the inside of the overdenture, there are clips or attachments that fit over the bar. These attachments ensure that the overdenture is held firmly and remains in place.
Bars provide an important splinting advantage when implants with limited dimensions or unfavorable angles are placed. This type of attachment contributes to good force distribution and the prevention of lateral displacing forces, thus offering adequate stability.
Magnetic attachments:
The attachment system is based on the magnetic principle. A magnet is placed on the implant or support tooth, and a separate magnet is placed in the overdenture. By the mutual attraction of the two magnets, the overdenture snaps onto the supporting tooth or implant.
Magnets were not previously widely used for dental purposes. Advantages include simplicity, low cost, automatic re-fitting after the overdenture is dislodged, self-adjustment, and no need for adjustment.
Telescopic attachments:
The telescopic attachment system consists of two crowns. The first is placed over the support teeth and takes the shape of the tooth. The second crown is placed inside the upper denture. After joining both crowns, the upper denture rests on the support tooth.
What factors influence the choice of attachment?
- Available bone
- Prosthesis expectations of the patient
- Financial ability of patient to cover treatment costs
- Personal choice and clinical expertise of dentist
- Experience and technical knowledge of the lab technicians.
Frequently Asked Questions About Overdentures
How are overdentures different from traditional dentures?
Overdentures are fixed with implants or natural teeth and provide better support and retention compared to traditional dentures that rely directly on the gums. Because overdentures are held up by natural tooth roots or dental implants, they are more stable and cause less discomfort and movement. Traditional dentures rely solely on vacuums or adhesives to keep them in place.
Is an overdenture permanent?
Due to their secure attachment to dental implants, fixed upper dentures are considered permanent. The wearer can remove removable upper dentures, but their design ensures greater stability compared to traditional removable dentures.
How long does an overdenture last?
With proper care and maintenance, dental implants can last a lifetime. For best results, you should replace your overdenture (the denture that fits over your implants) every 15 to 20 years.
Will I feel pain during the overdenture procedure?
Overdentures are usually performed under local anesthesia, allowing the patient to experience minimal discomfort during the placement of dental implants. Prescription painkillers and appropriate post-operative care can manage mild discomfort and swelling that some patients may experience in the days following surgery.
How long does an overdenture procedure take?
The duration of the overdenture procedure depends on the type of overdenture, the number of implants or support teeth placed. Both procedures will require more than one appointment. On average, it can take between 3 and 6 months.
How do I care for my overdentures?
- Remove and clean daily
- Brush remaining natural teeth and gums
- Regular dental check-ups
What materials are overdentures made from?
Overdentures can be made from acrylic, composite resins, or metal alloys.