Conventional dentures present a good option for full mouth tooth replacement because they can be the most cost-effective way to replace all of the upper teeth, lower teeth, or both. With well-made complete dentures, patients should minimally expect to restore their esthetics and facial support.
The biggest disadvantages of complete dentures are a greatly diminished ability to chew due to their poor stability and retention. Dental function is compromised with complete dentures, which causes difficulty eating the foods that require tearing and heavy chewing. For example, biting into a turkey sandwich would be quite difficult for most denture wearers, as would chewing most meats. Most denture patients would describe that wearing a lower denture is much more limiting and problematic than wearing an upper denture. A lower denture’s instability stems from the tongue’s movement, which dislodges the denture during chewing and speaking.
When a lower denture is a patient's chief complaint, dental implants can be used to improve the functionality of a complete denture. This can be done by creating a mechanism for the denture to snap onto the implants. This type of implant denture is called an overdenture. Implant supported overdentures, for many years, have been deemed one of the simplest ways to stabilize ill-fitting dentures. Since most upper dentures offer ample stability and retention without implants, many patients choose implant overdentures solely on the lower jaw.
What are Implant Overdentures?
For patients looking for a better, more comfortable way to wear a lower denture, the implant supported overdenture establishes significant denture stability and retention by snapping the removable denture onto at least two dental implants. As a rule, it is not necessary to use more than two implants to achieve the desired result. In fact, utilizing more than that can create issues with ease of insertion and removal. An "implant attachment" on the top of the implant is used to create a snapping mechanism, which is strong enough to keep the denture in position during chewing. It also allows for a relatively easy removal of the denture for daily cleaning and maintenance.
Advantages: The overdenture attachments keep the denture from pressing down too hard on the gum line, allowing an overdenture wearer to bite on harder foods without the typical discomfort a traditional denture wearer experiences when biting down hard. Most implant overdenture wearers report significant improvement the level of comfort and function that an overdenture provides versus a traditional lower denture.
A severe gag reflex can cause serious issues for patients wearing an upper denture. Since the fit of an upper denture is derived from the “suction” effect on the palate, coverage of the palate is a requirement for a good fit. When a patient has a gag reflex, it is impossible to extend the denture appropriately. In this situation, an implant overdenture can be a significant advantage and a comfortable remedy. With the retention of the denture coming from the snap mechanism of the implant attachments, the palate does not need to be fully covered, and thereby minimizes a patient’s gag reflex.
Disadvantages: Implant-supported overdentures can be less than ideal for a patient depending on treatment objectives. When the denture is still removeable and it sits on the gum line, functionality is not what one would expect from dental implant treatment. Compared to a typical denture, overdenture function is an improvement, but significantly less than the functionality of one’s natural teeth. Research indicates that a denture wearer’s function is only at 20% of full function. Overdentures can improve that percentage to 40 to 50% of normal biting force, but this still is well below what many people would expect from permanent tooth replacement using dental implants.
Maintenance: Over time, maintenance is required with any implant supported overdenture. The most common issue is wear and tear on the attachment. With repeated snapping in and out of the denture prosthesis, the overdenture attachments eventually wear out over time, resulting in diminished snap retention and perceived looseness of the overdenture. A typical replacement schedule is every 12 to 18 months. This maintenance procedure can be done at a normal cleaning appointment or as needed. There is a cost associated with replacement of the attachment parts, much like any regular maintenance. In addition, any denture that is supported on gum tissue will also incur change as it relates to quality of the fit, as the gum line may reduce or resorb. An implant overdenture will require occasional re-fitting as time goes on. One should expect to reline an implant overdenture every three to five years to maintain optimal fit.
Patients looking for the most cost-effective way to avoid the challenges of wearing a denture should consider the an Overdenture from their Hybridge doctor.