Implant supported prostheses
Dental implants can support a large variety of prosthetic devices. When planning for a type of implant supported restoration, several factors are involved :
- The number and position of missing teeth
- The overall clinical conditions
- Aesthetic and functional demands
- Geographical location : different types of prostheses can be designed in various parts of the world
- Whether a patient can afford the designed solution
- The expertise and preferences of each practitioner
An implant supported crown is normally indicated when a single tooth is missing. However, it is possible to design adjacent single unit crowns when several teeth are missing.
The dental crowns can be made of porcelain fused to metal alloys (gold, titanium, base metals), zirconia or all ceramics. The time of execution is relatively short and the prognosis is very good.
Many patients prefer fixed implant supported bridges because they do not have to be removed for cleaning. Bridges are permanently secured on the implants either with dental cement or with lag-screws. Large dental bridges supported by many implants can be quite expensive.
It is not advisable to design dental bridges that are supported by both natural teeth and dental implants (with some exceptions). This could lead to the loosening of the implants (because of natural teeth physiologic mobility) and failure.
The graphic above shows an implant in a bridge connection with a natural tooth. The movability of the tooth causes the chewing forces to act as a lever on the rigid implant situation.
It is also important to design enough implant units to adequately support the bridge. For example, if all teeth are missing and a fixed dental bridge is designed, at least 6 implants are required to support the bridgework.
An implant supported denture is a type of overdenture that is supported by and attached to implants. An implant-supported denture should be daily removed, to clean the denture and gum area.
Compared to a traditional denture (full denture) which rests exclusively on the gums, implant supported dentures allow chewing the food better, speak more clearly and is more stable.
Removable dentures are designed when a large number (most of the times, all) of teeth are missing. When a removable denture is worn, retainers to hold the denture in place are attached to the implants and the denture.
Most often, the retainers are made of two components :
A male-adapter attached to the implant
A female adapter housed in the denture. This part will require periodic replacement.
are attached to the implants
are housed in the denture
There are various types of adapters designed to hold overdentures in place : the ball-and-socket style retainer (image above) and the button-style adapter are just two examples.
Another variation is when a cast bar of metal is secured to the implants. The complete denture then attaches to the bar with attachments allowing no movement of the denture (image below).
Dental implants can be used as orthodontic anchors in order to align teeth. Orthodontic implants are different from the ones used for prosthetics, as there is no osseointegration. Mini-implants provide absolute anchorage and they have revolutionized the field of orthodontics.
Last review and update: February 2019