Implant-retained overdentures

No, and the distinction is commercially significant. An implant-retained overdenture is removable: you take it out to clean it, and it still rests partly on the gum. A fixed full-arch prosthesis such as All-on-4 is screwed in place and you do not remove it. The overdenture typically uses fewer implants, costs considerably less, and is easier to clean; the fixed option feels more like natural teeth and does not move at all. Both are legitimate; they answer different priorities.

Two implants in the lower jaw is a well-established minimum for substantially improving retention, and many people do very well with that. More implants can improve stability and distribute load better, and the upper jaw generally needs more because the support and bone quality differ. The right number depends on your bone, your bite and what you want from the result, so it should be explained in those terms instead of presented as a fixed formula.

It will be far more retentive than a conventional denture, but it is still a removable appliance resting partly on tissue, so a small amount of movement, particularly rotation around the attachments, is normal in most designs. What it should not do is lift, drop or shift when you eat or speak. If it does, that usually means the inserts have worn, the denture needs relining, or the design needs reviewing.

Attachment inserts are wearing components and lose retention gradually, so periodic replacement is expected. How often depends on the attachment type, how forcefully the denture is inserted and removed, and your bite. It is a small, routine and inexpensive procedure compared with the treatment itself, but it is a recurring cost worth knowing about at the outset. Replacing them before retention has completely failed makes for a much better experience.

Practices generally advise leaving the denture out for a period each day, usually overnight, so the tissue underneath is not covered continuously: the same principle as with a conventional denture. It also allows you to clean around the implant abutments properly, which is a separate task from cleaning the denture and is essential for preventing inflammation around the implants. Follow the specific instruction from the clinician who fitted it.

Sometimes. If the existing denture fits reasonably, the bite is correct and the base is sound enough to accommodate the housings, converting it can be a sensible economy. If it is worn, ill-fitting or the teeth have worn flat, converting it locks in those problems and a new denture is the better investment. This should be assessed and stated explicitly in the plan, because a quote for conversion and a quote for a new denture are different figures.

For lower complete dentures, the improvement in retention is often substantial and is the main reason the treatment exists. A well-made lower denture can still move because of anatomy, not workmanship. Against that, it involves surgery, cost, a healing period and ongoing maintenance of the attachments. If your current denture is stable and comfortable, the case is much weaker. The strongest indication is a lower denture that cannot be made to stay in place.

Locator-style stud attachments sit individually on each implant with a replaceable insert in the denture and are the most commonly used system today because they are straightforward to maintain. A bar joins the implants together and the denture clips onto the bar as a unit, which can distribute load more evenly but is harder to clean underneath. Ball attachments are an older individual-stud design still in use. Which suits you depends on implant number, position and spacing.

Sometimes, depending on how many implants were placed and their position. A fixed prosthesis generally needs more implants, positioned to support a rigid, non-removable structure, than a retention-focused overdenture does. Whether an upgrade is possible without additional implant surgery is a case-specific question worth asking at the planning stage if a fixed result might be wanted eventually, since it can affect how the first implants are placed.

Most people notice a real improvement in confidence and chewing ability because the denture no longer lifts or shifts unpredictably, particularly with a lower denture that previously moved during function. It still is not identical to natural teeth or to a fixed prosthesis. There is still some movement at the attachments and the appliance still rests partly on the gum, so adaptation takes a little time even after the retention itself is much improved.

Not always: one benefit of adding implant retention to an upper denture is that, with enough implants providing stability, the palate coverage can sometimes be reduced or removed, which improves taste sensation and comfort for some wearers. Whether this is appropriate depends on implant number and position and how much retention they actually provide, and it should be discussed explicitly instead of assumed to come automatically with implants.

In most protocols the existing denture is adjusted so it sits without pressing on the healing implant sites, and it is worn essentially as it was before, without the retention benefit, until the attachments are connected later. Managing that expectation matters, because the interval can be a period of no functional improvement despite implants already being in place, and knowing that in advance avoids unnecessary disappointment.