Why a front implant crown can look shorter years later

In a follow-up study of front implant crowns checked 11 to 21 years after they were fitted, about two in three sat slightly higher than the teeth beside them, so the implant tooth looked a little shorter. Most of those steps were tiny: only 8% measured 1 mm or more, and most people in the study had not noticed any difference. This is usually not because the implant has sunk; it is generally explained by the natural teeth around it continuing to move.

The implant stays put while natural teeth keep moving

A natural tooth is held in its socket by a thin ligament, and teeth can continue to erupt slowly through adult life as the face and jaws change. An implant is joined directly to the bone, so it behaves more like a fixed point. A 2023 narrative review by Papalexopoulos and colleagues (Journal of Esthetic and Restorative Dentistry) describes this as the reason vertical differences can appear between implants and the teeth next to them, at any age.

When the neighbouring teeth keep erupting, the implant crown can be left behind. The result can be a step at the biting edge, a gum line that sits higher on the implant than on its neighbours, or both. Dentists call this infraposition or infraocclusion.

A Stockholm study by Winitsky and colleagues (Clinical Oral Implants Research, 2021) used the implant as a fixed reference and measured how the teeth beside single front implant crowns in 30 patients had moved after 14 to 20 years. Movements ranged from nothing to 2.5 mm, mostly downwards and towards the palate, and 30% of patients had more than 1 mm of downward movement.

This is not only a problem for teenagers

In young people, implants are usually delayed until growth has finished, because the jaws are still changing; a 10-year study by Thilander and colleagues (European Journal of Orthodontics, 2001) described implants as a good option in adolescents provided dental and skeletal development is complete. Our article on implants for a missing lateral incisor after braces explains that timing question for younger patients. Steps can also appear when an implant is placed well after growth has stopped.

Bernard and colleagues (Journal of Clinical Periodontology, 2004) compared 14 patients aged 15.5 to 21 with 14 patients aged 40 to 55, all with front implants, followed for an average of about four years. Every patient in both groups showed some vertical step, ranging from about 0.1 mm to 1.9 mm, and the authors concluded that mature adults can show steps to the same extent as adolescents and young adults. More recently, Ormianer and colleagues (International Journal of Oral and Maxillofacial Implants, 2025) looked back at 32 front implants placed in 30 people over 40, followed for an average of 14 years, and found that infraocclusion may progress over time in adults.

A 2021 systematic review by Klinge and colleagues (Acta Odontologica Scandinavica) agreed that a long-term risk of infraposition can be seen in some cases, but found the evidence very limited and the reasons some people are affected more than others not well understood.

What the long-term studies found

Most of the studies are small and they were designed differently, so they do not agree on every risk factor. Their main findings are set out below.

A Class II division 1 bite is one where the upper front teeth sit well ahead of the lower teeth. In the Ormianer study, more eruption of the neighbouring teeth also went with more bone loss around the implant, although the study could not show which came first.

A small step can matter more in a high smile

Whether a step is noticeable depends a lot on how much of the teeth and gum a person shows. Ntovas and colleagues (International Journal of Oral and Maxillofacial Implants, 2024) asked 80 dentists and 80 people without dental training to rate digitally altered photos of one man's smile, so this was a photo study rather than a study of patients. With a high smile line, a step as small as 0.25 mm on a central incisor, or 0.5 mm on a lateral incisor or canine, lowered how attractive both groups rated the smile. With a medium smile line, the threshold was about 0.5 mm for the central and lateral incisors.

In real patients the picture is gentler. In the Sauvin study (Clinical and Experimental Dental Research, 2022), 8 of 23 patients had noticed the step and 4 wanted something done about it. In the Landin study, people with a step of 0.5 mm or more were more likely to notice it, but satisfaction stayed high overall. Winitsky found that patients rated the look of their implants more highly than dentists did.

Colour and contacts can change as well

A step is not the only change that can appear over the years. Landin and colleagues found that the colour match between implant crowns and the natural teeth beside them scored lower than shape, and that colour mismatch increased over time. Our article on matching an implant crown to your natural tooth shade covers why this happens.

The contact between an implant crown and the tooth beside it can also open up. Papalexopoulos and colleagues note that a firm contact may be lost within a few months of the crown being fitted, which can trap food. If floss now slides through easily or food keeps catching in the same spot, see our guide to food getting stuck around an implant crown.

What can be done about a shorter-looking implant crown

A small step that does not bother you, with healthy gums and stable bone on the X-ray, may simply be watched at check-ups. If it does bother you, the options depend on where the step is and how much gum shows when you smile.

One option is to replace the crown with a new one shaped to match the current position of the neighbouring teeth. This can bring the biting edge back into line, but it does not lower the gum line on the implant. Based on their rated photos, Ntovas and colleagues concluded that in a high smile, restoring the edge alone may help a lateral incisor but is unlikely to solve the problem on a central incisor, and may look worse on a canine. Crowns that are held by a screw can usually be taken off and changed more easily than cemented crowns; our article on screw-retained and cement-retained implant crowns explains the difference.

Where the gum line is the main concern, the choices become more involved, and in some situations a dentist may talk about removing and replacing the implant itself. That is a bigger step with its own risks, covered in whether an implant can be removed and replaced. The right choice depends on the bone, the gum, the bite and how much the change affects you.

Things worth raising at your next check-up

Mention any of these if you have an implant in the front of your mouth:

• the implant tooth looks shorter, or its edge sits higher than the teeth beside it
• the gum on the implant sits higher than on the neighbouring teeth
• food has started to catch next to the implant, or floss passes through more easily than it used to
• the implant crown looks a different colour from your natural teeth
• the gum around the implant bleeds, feels sore or looks swollen

The last point matters more than the others, because bleeding or swelling can be a sign of inflammation around the implant and should be checked rather than watched. Photos from when the crown was fitted, if you have them, can help show how much has changed.

Common questions

Does a shorter-looking implant crown mean the implant is failing?

Not by itself. In the Landin study, 99% of implants were still in place after 11 to 21 years even though most crowns showed some infraposition. Bone loss around the implant is a separate question, and it is checked with an examination and X-rays.

Can it be prevented?

There is currently no proven way to stop the neighbouring teeth from moving. The Klinge review found the evidence on risk factors very limited, so it is not yet possible to say reliably who will be affected. Papalexopoulos and colleagues recommend careful planning, regular reviews and restorations that can be removed and changed if needed, so that a step can be managed early.

Will the step keep getting bigger?

It may. The Ormianer study found that infraocclusion in adults may progress over time, and the Winitsky study measured movement of the neighbouring teeth of up to 2.5 mm after 14 to 20 years. How much it changes varies from person to person.

Getting an older implant checked

Lumi Dental places and restores dental implants, and our 3D X-ray lets the dentist look at the bone around an older implant in detail. If your implant was placed elsewhere, bring any records you have. You can read more on our dental implants page or in our implant questions. If you live outside Sydney, you can send photos and X-rays first; our guide to travelling to Sydney for dental treatment explains how that works. To have an implant looked at in Melrose Park, book an appointment.

Sources

• Landin N, Kaya C, Papia E, Eliasson A. Infraposition, esthetics, survival, and complications of implant-supported crowns in the anterior maxilla: a retrospective study with 11-21 years follow-up. Int J Oral Maxillofac Implants. 2025. PubMed 41201968
• Winitsky N, Naimi-Akbar A, Nedelcu R, Jemt T, Smedberg JI. 3-D tooth movement adjacent to single anterior implants and esthetic outcome. A 14- to 20-year follow-up study. Clin Oral Implants Res. 2021;32(11):1328-1340. PubMed 34403160
• Bernard JP, Schatz JP, Christou P, Belser U, Kiliaridis S. Long-term vertical changes of the anterior maxillary teeth adjacent to single implants in young and mature adults. A retrospective study. J Clin Periodontol. 2004;31(11):1024-8. PubMed 15491321
• Ormianer Z, Biadsee A, Shlomi E. Eruption of adjacent teeth following anterior maxillary implant placement in older adults: a 14-20-year follow-up. Int J Oral Maxillofac Implants. 2025. PubMed 41385654
• Sauvin G, Nurdin N, Bischof M, Kiliaridis S. Assessment and aesthetic impact of a long-term vertical discrepancy between the single anterior maxillary implant-supported crown and adjacent teeth: a retrospective cross-sectional study. Clin Exp Dent Res. 2022;8(5):1109-1116. PubMed 36029165
• Klinge A, Tranaeus S, Becktor J, Winitsky N, Naimi-Akbar A. The risk for infraposition of dental implants and ankylosed teeth in the anterior maxilla related to craniofacial growth, a systematic review. Acta Odontol Scand. 2021;79(1):59-68. PubMed 32835562
• Ntovas P, Soundia M, Karveleas I, Ladia O, Tarnow D, Papazoglou E. The influence of a single infrapositioned anterior ankylosed tooth or implant-supported restoration on smile attractiveness. Int J Oral Maxillofac Implants. 2024;39(5):745-754. PubMed 38498787
• Thilander B, Odman J, Lekholm U. Orthodontic aspects of the use of oral implants in adolescents: a 10-year follow-up study. Eur J Orthod. 2001;23(6):715-31. PubMed 11890067
• Papalexopoulos D, Samartzi TK, Tsirogiannis P, et al. Impact of maxillofacial growth on implants placed in adults: a narrative review. J Esthet Restor Dent. 2023;35(3):467-478. PubMed 35929493

This article is general information only and is not a substitute for advice about your own situation from a dentist.