Molars do most of your chewing, so losing one changes how you eat. This guide explains how implants are used at the back of the jaw and what is different there.
Key points
- Molars do most of your chewing, so a missing molar changes how you eat even if the gap does not show.
- Options are an implant, a fixed bridge, a partial denture or leaving the gap, and not every gap needs filling.
- The upper back jaw sits beside the sinus and the lower back jaw has a nerve, so a 3D scan is used to plan the post.
- Molars take the heaviest bite, so the post size, the bite and regular check-ups matter.1
- In a review of 26 studies, 96.8 percent of implants supporting single crowns were still in place after five years.3
Molars are the large teeth at the back of the mouth. They are built to crush and grind food, and they take the heaviest biting forces of any teeth. When a molar is lost, the load shifts to the teeth that remain, and the gap can change the bite over time. Replacing a molar is therefore about function more than appearance, and implants are one option.
Why a missing molar matters
You may not see a missing molar when you smile, but you can feel it.
- Chewing is less efficient. You may chew on the other side, which loads it more heavily.
- Teeth can move. The tooth in front can tilt back into the gap, and the tooth above or below can grow down into it, which changes how the teeth meet.
- Food packs into the space. A gap can trap food and make cleaning harder.
- The bone changes. The jawbone where the root was loses volume over time.
A gap can make eating and speaking harder and can change how the face and smile look.4 Not every gap needs filling, and your dentist can tell you whether yours is likely to cause problems.
Replacement options
An implant. A titanium post is placed in the bone and a crown is fixed to it. The neighbouring teeth are not shaped. Our guide to dental implants explains the process.
A fixed bridge. This needs the teeth beside the gap to be shaped to carry crowns. At the very back of the mouth, there may be no tooth behind the gap, which limits the design. Read more in bridge or dental implants.
A denture. A partial denture is removable and needs no surgery, although it can feel bulky at the back of the mouth.
Leaving the gap. Some people choose this, particularly if the gap is at the very back.
How implants cope with heavy chewing
Molars take the greatest chewing forces, so the planning matters.
- Size and number of posts. A molar has two or three roots, so a single narrow post may be less suited than a wider one, or two posts may carry a large crown or a bridge.
- Bite. Your dentist checks how your teeth meet, and the crown is adjusted so that it does not take too much force. NHS guidance says grinding can overload implants, so tell your dentist if you grind.1
- Regular check-ups. The crown or the screw can wear or loosen and may need repair, which is why check-ups matter.2
What is different at the back of the jaw
The upper back jaw sits beside the sinus. The bone under the sinus can be thin, especially after a tooth has been lost for some time. If there is not enough, your dentist may advise a bone graft, which adds at least four months to treatment and can bring swelling, bruising and pain.12 Sometimes a shorter post, or a different position, avoids the need for a graft. A 3D scan shows how much bone there is.
The lower back jaw has a nerve. A nerve runs through the lower jawbone and supplies feeling to the lip and chin. The scan shows where it lies, and the post is planned to keep a clear distance. Altered feeling or numbness in the lip or chin is very rare and usually settles.1
Access is harder. The back of the mouth is more difficult to reach and keep clean, so cleaning around a back implant needs interdental brushes or floss, and your dentist can show you how.
At Orion Dental Clinic, both doctors place implants, and planning uses a 3D scan (CBCT) so that the post is positioned from your own bone.
The timeline
For a single molar, NHS guidance says the whole process could take 6 to 12 months, with three to six months of healing before the crown is fitted.12 A bone graft adds at least four months.1 After the tooth is fitted, check-ups are advised every three to six months over the long term.1
What the research says
In a review of 26 studies, 96.8 percent of implants supporting single crowns were still in place after five years.3 The same review found that, over five years, the screw or abutment loosened in 12.7 percent of cases, and gum problems occurred next to 9.7 percent of crowns.3 These are figures for groups of patients, and they are why follow-up is part of the plan.
Looking after a molar implant
- Brush twice a day and clean between the teeth.
- Use an interdental brush around the implant, at least once a day.
- Do not smoke, because smoking raises the chance that an implant does not bond.1
- If you grind your teeth, ask about a night guard.
- Keep your check-ups.
What the scan checks at the back of the jaw
A 3D scan answers questions that an ordinary X-ray cannot. For a molar, it shows:
- how much bone lies under the sinus in the upper jaw, and whether a graft or sinus lift is likely to be needed;
- how far the bone sits above the nerve in the lower jaw, which limits the length of the post;
- how wide the bone is, because a molar is a broad tooth and a thin ridge may need a graft;
- the thickness and health of the gum around the site;
- the position of the roots of neighbouring teeth.
With this information the dentist can plan the length, width and angle of the post before surgery, and explain why a graft or a different design is advised.1
Building back up to normal chewing
After the molar crown is fitted, your bite is adjusted and you can use the tooth. In practice, most people ease back in.
- In the first days, chew softer food, and cut hard food into small pieces.
- Build up to your normal diet over a few weeks as the tooth feels comfortable.
- Chew on both sides, so one side does not carry all the load.
- Avoid biting down hard on very tough items, such as ice or hard sweets, which can chip any crown.
- Tell your dentist if the tooth feels high, if food catches or if the bite feels uneven.
A quick guide to choosing
| Situation | What often applies |
|---|---|
| A single molar missing, healthy neighbours | An implant leaves the neighbours alone |
| A single molar missing, neighbours already crowned | A bridge may be an option, though a tooth at each end is needed |
| The very last molar missing | Often an implant, since a bridge has nothing behind it to hold |
| Very little bone under the sinus | A graft, a sinus lift or a different option |
| A health condition or medicine that affects healing | A denture or a bridge may be safer to discuss |
Your dentist decides after an examination and a scan, and a good plan explains why other options were not chosen.
Myths and facts about back-tooth implants
Myth: back teeth cannot be replaced by implants. They can, with careful planning around the sinus and the nerve.
Myth: you must always have a sinus lift for an upper molar. Not always. The scan shows how much bone there is.
Fact: molars take the heaviest bite, so the bite is checked carefully. The crown is adjusted so that it does not take too much force.1
Practical advice
- Chew on both sides while you heal, once your dentist allows.
- Use an interdental brush daily at the back of the mouth.
- If you grind, ask about a night guard.
- Do not smoke.1
Frequently asked questions
Can a molar be replaced by an implant on the day it is removed?
Sometimes, depending on the bone around the socket and the state of the gum. Your dentist decides after an examination and imaging, and may suggest waiting if there is infection.
Do I need a bone graft for an upper molar?
Not always. The bone under the sinus can be thin, and a scan shows whether a graft is needed. Our article on bone grafts for dental implants explains the options.
Will my implant feel different to chew with?
Once the bone has bonded and the crown is fitted, the tooth can be used for biting and chewing much like a natural one.1
What if two neighbouring molars are missing?
Two posts can carry a bridge, or a single post can carry a bridge with an extension. Your dentist plans this from your bone and your bite. See implant bridges for how it works.
Will a molar implant feel like my natural tooth?
Once the bone has bonded and the crown is fitted, it can be used for biting and chewing much like a natural one.1
Can two molars be replaced together?
Yes, with two posts or a bridge on implants. Your dentist plans from your scan.
Do I need to replace a molar at all?
Not always. Some people choose to leave a gap, particularly at the very back. Ask your dentist what is likely to happen to the neighbouring teeth and your bite if the gap stays.
Does an implant at the back of the mouth hurt more?
Surgery is done under local anaesthetic, so you should not feel pain, whatever the site. Recovery is similar, with swelling and discomfort for a few days.1
About the author
Dr Anupam Sinha, BDS, MDS – Orthodontics. BDS (2002), KLE Vishwanath Katti Institute of Dental Sciences, Belgaum. MDS in Orthodontics (2006), SDM College of Dental Sciences, Dharwad. His thesis work won a national research award in 2005, and he holds a certification in aesthetic dentistry. He sees patients at Orion Dental Clinic in Greater Kailash 1, South Delhi. Read the full profile of Dr Anupam Sinha.
Sources
- Cambridge University Hospitals NHS Foundation Trust. Dental implants in restorative dentistry (patient information). https://www.cuh.nhs.uk/patient-information/dental-implants-in-restorative-dentistry/
- Guy's and St Thomas' NHS Foundation Trust. Dental implants (patient information). https://guysandstthomas.nhs.uk/health-information/dental-implants
- Jung RE, Pjetursson BE, Glauser R, Zembic A, Zwahlen M, Lang NP. A systematic review of the 5-year survival and complication rates of implant-supported single crowns. Clinical Oral Implants Research, 2008;19(2):119-130. https://pubmed.ncbi.nlm.nih.gov/18067597/
- NHS website. Dentures (false teeth) (patient information). Page review date 19 March 2025. https://www.nhs.uk/conditions/dentures/
Medically reviewed by Dr Anupam Sinha, BDS, MDS – Orthodontics, on . General information for patients from Orion Dental Clinic, last updated 23 October 2026. It is not advice for one person, so ask a dentist what suits you. To report an error, contact us.