Do You Need a Dental Implant? When a Missing Tooth Is Worth Replacing

When an implant is considered

• A missing tooth that bothers you. People usually look for a replacement because of difficulty eating or speaking, or because of how the gap looks², even when it causes no other problem.
• A tooth that cannot be saved. A tooth broken below the gum, split or too loose to keep may have to be taken out. If a tooth can be treated, for example with root canal treatment, that is worth discussing first. A review of 143 studies found similar long-term survival for root-canal-treated teeth and single crowns on implants³; very few studies compared the two directly, so neither can be called better.
• A denture that no longer fits. A denture that clicks when you talk, slips, hurts or no longer fits² needs a dentist's check. It may be adjusted, relined or remade; for some people, implants that hold a bridge or a denture are one of the options.

What can happen when a gap is left

The evidence here comes mostly from small or older studies of back teeth, so it describes what can happen, not what always happens.

• The bone shrinks. After a tooth is taken out, the bone that held it becomes narrower and lower, mostly in the first months⁴. This can matter if an implant is planned later, because an implant needs enough bone around it.
• Neighbouring teeth can tip or drift into the space. In one study of untreated back-tooth gaps, the teeth moved fastest in the first two years, and later movement was usually gradual and minor⁵ over the years studied. It varies from person to person.
• The opposing tooth can move towards the gap. In a study of back teeth, this movement was linked with loss of gum attachment⁶, that is, where gum disease has weakened the support. Studies disagree on how much it moves.
• Chewing depends on how many teeth are left and where. A review found that chewing is linked to the number of remaining teeth and how they meet⁷. People missing only some back molars often manage well (see below).
• Appearance and confidence. The same review found that appearance and satisfaction are markedly affected when front teeth are lost⁷.

Common beliefs about missing teeth, and what the studies show

Lists of signs often go further than the evidence. In the sources we reviewed:

• The sources we reviewed do not show that a missing back tooth causes jaw-joint (TMJ) problems. A review found no relationship between jaw-joint problems and bite (occlusal) factors⁷.
• There is no evidence here that a missing tooth causes digestive problems or poor nutrition.
• 'Your teeth will collapse into the gap' is not what the studies found. The authors of one long study of single missing back teeth wrote that the expected consequences did not occur with the frequency or severity generally assumed⁸.
• The studies on facial change that we found are in people who have lost all their teeth, not one or a few.
• There is no fixed deadline for replacing a missing tooth, and we found no study linking a given delay to a worse result. The bone does change, though: if a tooth is to be taken out and you may want an implant, ask about timing beforehand, because a later implant may need a bone graft.

Not every gap has to be filled

For some back-tooth gaps, leaving the space and checking it at regular visits is a reasonable choice. A review of trials on the shortened dental arch, a set of teeth missing some back molars, found the results encouraging for chewing function and satisfaction⁹. For a single missing back tooth, the long study above concluded that immediate treatment may not be critical, and that regular follow-up may be warranted.

Front teeth are different: as the review above found, losing them affects appearance and satisfaction markedly. What bothers you counts as much as what the X-ray shows.

What decides whether an implant suits you

• Gum health. Gum disease is treated first. People treated for periodontitis lost implants at about 1.75 times the rate¹⁰ of people without that history, and peri-implantitis, inflammation with loss of the bone around an implant, was about 3 times more common.
• Smoking. In people smoking more than 20 cigarettes a day, implant loss was about 2.5 times as likely per implant¹¹. Per patient it was about 4 times as likely. No safe number of cigarettes has been shown.
• Clenching or grinding. The odds of implant failure were about 2.2 times higher¹² in people judged likely to clench or grind.
• Diabetes and medicines. For diabetes the findings on implant loss are mixed. Two of three reviews found no significant difference (2021 review¹³; 2016 review¹⁴), and the third reported a higher odds ratio¹⁵. All three found more bone loss around implants, so blood-sugar control, daily cleaning and regular reviews matter. Bone-strengthening medicines such as bisphosphonates were linked with more implant loss per implant¹⁶, and jaw osteonecrosis, the death of jaw bone linked to the medicine, was about 3.5 times more likely per patient, on very low-certainty evidence. The risk depends on why, at what dose and for how long the medicine is taken; doses used for osteoporosis are assessed separately from those used in cancer treatment. Tell your dentist about every medicine you take, and do not stop one without asking the doctor who prescribed it.
• Age. Implant treatment waits until the jaw has stopped growing.
• Bone. Where there is too little bone, grafting may be discussed. A Cochrane review found it unclear which technique or material works best¹⁷; complications are common, especially when the bone has to be built up in height, and in a shrunken lower jaw short implants appear to be a better option than building it up. See bone grafting.

These are associations from observational studies, not your personal risk.

The options for a missing tooth

• An implant with a crown. An implant is a post placed in the jawbone that holds a replacement tooth; it does not need the neighbouring teeth for support. In pooled studies, about 97 in 100 single implants were in place after five years and about 95 after ten; the crown is replaced more often, with about 89 in 100 in use after ten years. Loose screws and gum problems around implants were common, and these are pooled averages, not a promise for one person. Surgery has its own risks: bleeding, swelling, bruising and infection can occur; in the lower jaw the lip and chin can go numb, usually temporarily and rarely permanently, and in the back of the upper jaw the sinus is close. An implant needs daily cleaning and regular check-ups. See dental implants.
• A bridge. A conventional bridge is fixed to the neighbouring teeth, which are ground down to carry it; a resin-bonded bridge needs little or no grinding, but it can come loose.
• A removable denture, partial or complete.
• Leaving the gap, where that is reasonable (see above).

The reviews we used found no head-to-head comparison of implants, bridges and dentures for a missing tooth, so we do not rank them here. Ask your dentist what each option means for your teeth, your gums and your daily life.

When to see a dentist

After a knock to the mouth, see a dentist straight away if a tooth is knocked out, and the same day if a tooth is chipped, loose or pushed out of place. Book a visit if a tooth feels loose, if a denture slips, hurts or no longer fits, or if your gums bleed or are swollen. A gap you have had for years is also worth mentioning at your next check-up, so that the teeth around it can be monitored.

Emergencies. Difficulty breathing or swallowing, rapidly spreading swelling of the face or neck, high fever or swelling around the eye are serious signs. Go to the nearest emergency department or call 112.

Frequently asked questions