You might have seen ads for 2 or 4 dental implants holding a full denture (overdentures) and wondered which is better for your current condition. You might even be confused as to whether you can opt for 2 or 4 dental implants.
This article has been written to help you make a more informed decision before heading in for your overdenture consultation.
What Exactly Are Overdentures?
Overdentures are removable full-arch prosthetic teeth replacement solutions that are fitted onto dental implants. They are often more affordable than All-on-4 dental implants or full-arch dental implants that are individually placed.
In many instances, overdentures are the preferred upgrade for patients who are currently on dentures. While full dentures can sometimes be a challenge to eat or speak with properly, overdentures can help alleviate some of the common challenges that dentures pose.
In Singapore, it is common to place 2 to 6 dental implants to a single overdenture arch depending on your bone density and quality, your current oral health, the size and shape of your dental arch, your functional and aesthetic requirements and your budget.
What is the Difference Between 2 and 4 Dental Implants Overdentures?
Besides the cost difference, the main difference between 2 and 4 dental implants for a single arch overdenture would be the stability of the overdenture.
2 dental implants overdentures are generally more affordable but can be less durable. Because there is increased stress on the 2 dental implants, it can lead to faster wear and potential complications (e.g. implant failure or loosening). Over time, the prosthesis may require more maintenance or adjustments.
The 2 dental implants overdenture may also feel loose or unstable at times, especially if you are placing the implants in areas with less bone density.
I generally do not recommend 2 dental implants for your overdentures if it is on the upper arch as there is increased risk of implant failure from the uneven distribution of weight and pressure. There is also a higher risk of fracturing your implant and overdenture prosthesis. 4 dental implants overdentures have more stability because of a more evenly distributed force on the prosthesis.
In some cases though, it might not be necessary or suitable for you to place 4 dental implants on the lower arch because of lack of bone. In lower arches, gravity can do most of the job in holding the overdentures in place.
While the ideal set-up would be 4 dental implants for each arch, if you do not have sufficient bone or wish to avoid critical anatomical structures (e.g. your nerve) in the lower arch, you will be given the option to opt for 2 dental implants to an overdenture instead.
Would full-arch dental implants be better than overdentures?
Some patients ask me: Doctor, since dental implants are now so affordable in Singapore, should I just place 12-14 dental implants with dental crowns instead of doing an overdenture?
Now, theoretically that is indeed possible.
However, there are some drawbacks to placing 12 to 14 dental implants instead of 2 to 4 dental implants to an overdenture bridge. One of the most significant drawbacks would be undergoing extensive surgery and healing for 12 to 14 surgical sites (yikes!).
There is usually a higher chance of complications when that many dental implants are placed. Instead of healing from just 4 surgical sites from an overdenture bridge, your body will have to work harder overtime to heal from 12 to 14 surgical sites.
Having that many dental implants in your mouth means that eating can become very uncomfortable and difficult. You can expect to be on a very soft diet for at least 1-2 weeks post-surgery and refrain from having solid foods for at least 3 months till your implants have osseointegrated and it is possible to restore your implant crowns.
Placing 12 to 14 surgical sites also means a longer in-chair duration. If one implant takes about 20 to 30 minutes to be placed, you can expect to sit in the dental chair for at least 4 hours. For older patients, this can be extremely stressful and physically taxing.
For overdentures, it is possible to issue a temporal denture bridge immediately after implant surgery. This temporal overdenture bridge helps you look, eat and chew a bit more normally. However, if you are intending to do 12 to 14 implant surgeries, it will not be advisable to place any form of prosthesis while you are healing as it increases the probability of implant failure.
If cost is your main concern, although you can usually expect to pay less per implant (e.g. $128 out of pocket per implant), the overall cost might be more with more dental implants (e.g. $750 for an overdenture bridge vs $1,792 for 14 dental implant crowns post Medisave subsidy).
While it is not impossible to place a full-arch of dental implants, it is generally not recommended by dentists or dental specialists.
If what you are looking for is stability and longevity without the high price tag (e.g. All-on-4 dental implants), overdentures can be a great option.
Factors that Affect Whether You Should Take Up 2 or 4 Implant-Supported Dentures
If you have recently gone into a dental clinic with the hopes of getting 4 dental implants supporting an overdenture, and found out that you are only suitable for 2, you might be slightly disappointed.
Sometimes, dentists do not recommend taking up 4 dental implants if you do not have enough bone to support the dental implants, if there is an anatomical structure that might require further surgeries before placement of the dental implants or if your budget does not allow for it.
I have listed down some of the critical factors that will affect whether you should take up 2 or 4 dental implant supported dentures:
Upper vs Lower Jaw
Jaw anatomy is the key foundation in how many dental implants you require.
- Lower Jaw (Mandible): 2 dental implants are often sufficient to stabilize a denture.
- Upper Jaw (Maxilla): Usually needs 4 implants due to softer bone and higher biting forces.
Jawbone Condition and Bone Density
The stronger and wider your bone, the more implant fixtures it can hold. A CBCT 3D scan can help your dentist assess whether you are suitable for 2 or 4 dental implants.
- 2 Implants: Suitable if you have limited bone volume or bone loss in certain areas. Less surgical intervention required.
- 4 Implants: Requires more bone support but offers greater overall denture stability. Bone grafting might be needed.
Existing Health Conditions
If you currently have pre-existing or past health and medical conditions, it can affect the success of your dental implants.
- Conditions like diabetes, osteoporosis, or smoking habits can affect healing and implant success.
- Patients who are undergoing radiation therapy (chemotherapy) or have had chemotherapy for cancer treatment are at higher risk of implant failure.
- In some cases, fewer implants may be safer or more predictable.
Denture Stability
If you are looking to prevent denture bridge movement, 4 dental implants supporting the bridge are often the better choice.
- 2 Implants: Gives moderate stability. Some movement of the denture is still possible if you tend to eat a lot of hard or chewy foods like steak.
- 4 Implants: Offers excellent retention and minimal movement. Feels more natural for chewing and speaking.
Age and Long-Term Goals
If you are looking to upgrade to a fixed solution later, 4 dental implants will be a better choice.
- Younger Patients: Might benefit more from 4 implants to reduce long-term bone loss and improve lifestyle quality.
- Older Patients: May prefer 2 implants for simpler surgery and cost-effectiveness.
Budget and Affordability
When investing in overdentures, it might be wise to consider lifetime value. 2 dental implants might be more affordable but 4 dental implants will offer greater comfort, flexibility in shifting to fixed bridges and fewer adjustments in the future.
- 2 Implants: More affordable upfront. Often paired with a removable overdenture.
- 4 Implants: Higher initial cost, but with more stability. Feels more like natural teeth. Can be converted into a fixed solution (All-on-4 fixed bridge) in the future.
So Which is Better for Me: 2 or 4 Dental Implants Overdentures?
There is no one-size fits all!
It is largely dependent on the factors mentioned above, as well as your personal preferences. If you need further guidance before making a decision, let me help guide you through this process.
You should go for 2 dental implants for your implant-supported dentures if you:
- Are looking for a more affordable solution that offers strong retention
- Have less bone to support implants in your jaw
- Do not mind some minor movement of the prosthesis while chewing
- Are intending to switch from full dentures to overdentures for better stability.
You should go for 4 dental implants instead if you:
- Want the most stable and secure fit with minimal or no movement
- Are younger or more active and want maximum confidence when eating or speaking
- Want to reduce long-term bone shrinkage
- Are okay with a higher upfront cost for more comfort and fewer future adjustments.
The following are a list of questions you can ask yourself to determine what kind of experience you want with your teeth:
| Question | Honest Recommendation | |
| If NO | If YES | |
| Am I okay with not eating too tough, crunchy or chewy foods? | 4 dental implants | 2 dental implants |
| Do I want the most affordable option right now? | 4 dental implants | 2 dental implants |
| Do I want something that feels as close to natural teeth as possible? | 2 dental implants | 4 dental implants |
| Am I okay with some movement when I chew on tough and chewy foods? | 4 dental implants | 2 dental implants |
| Am I intending to change my overdentures to a fixed bridge in the future? | 2 dental implants | 4 dental implants |
I am not ready for implant-supported dentures. Can I do a full denture then change over to an overdenture later?
The answer to this question is not a no, but it really depends.
If you are looking to save money on a new prosthesis, this might help you understand when a new denture might be required.
For some patients, it is possible that their existing full denture can be converted into an implant denture (overdenture). To help our patients save costs, we sometimes convert the existing full dentures they have into their final prosthesis.
There are, however, situations that require an entirely new prosthesis. These situations include:
- The design of your current dentures and whether they are suitable to be converted into an overdenture;
- The material of your current dentures and whether it can be adjusted to fit with your implants;
- The anatomy of your supporting gums and jaws;
- The position of your dental implants in relationship to your current dentures;
- Whether your dentures are in good condition.
If you are planning to re-use your dentures as an overdenture prosthesis in the future, it might be a good idea to inform your dentist about this beforehand.
Can I have overdentures if I have gum disease?
You should not proceed with overdentures treatment if you have gum disease. Your priority should be on treating and getting your gum disease under control before proceeding with overdentures. This is not a “no,” but a “maybe later.”
Gum disease (periodontal disease) can affect the health of your gums, bone and teeth. Weak gums and bone can cause implant failure, which can be detrimental to the success of your overdentures treatment. This makes it essential to address gum disease before getting overdentures.
Once the gums are healthy and stable, overdentures supported by implants can be a very effective solution to restore function, comfort, and aesthetics.
My dentist says that I need to do a sinus lift before placing implants for my overdentures. Do I really need to do a sinus lift?
If you have been asked to do a sinus lift before placing implants and are wondering whether it is really required, the answer is it really depends!
Some of the factors that would determine this are whether you have sufficient bone in your upper jaw to place your implants, whether there is risk of your implants moving into your sinus region because of lack of bone and whether you have lost your teeth for several years resulting in bone loss.
You can use the following table as a guide for whether you need a sinus lift (if your dentist says you need one):
| Question | Reason | |
| Is your dental implant going to be placed in the upper back jaw? | If the answer is yes, then you most likely require a sinus lift. | The upper back jaw is where your sinuses sit. The bone is often very thin there. |
| Have you been missing teeth for several years? | If the answer is yes, then you most likely require a sinus lift. | Bone loss often worsens over time. |
| Is your dentist intending to place long implants for better stability? | If the answer is yes, then you most likely require a sinus lift. | Longer implants require more vertical bone. |
| Do your CBCT 3D scans show less than 4-5mm of bone height on your upper jaw? | If the answer is yes, then you will require a sinus lift. | There is not enough bone to place dental implants (even shorter dental implants) safely. |
What is Right for You is More Than The Number of Dental Implants or the Cost
Choosing between 2 or 4 dental implants for your overdentures is not just about the cost. It is also about how you want your new teeth to feel, function and last over time.
If you are looking for an affordable upgrade from full dentures, and are okay with some movement, 2 implants may be enough, especially for the lower jaw. If you want better bite strength, minimal movement, or a path toward fixed implant teeth in the future, 4 implants are usually the better long-term investment.
However, your final treatment plan will depend on many factors such as your jawbone structure, overall health, budget, and even whether you need a sinus lift.
At toofus™ Dental, our job is not to sell more implants to you. It is to help you make clear and confident decisions that can suit your life, personal preferences and lifestyle goals.
If you are unclear as to which option would be more suitable for you, please feel free to drop us a message. We will walk you through your options with full transparency and no pressure.
