Expert Witness Journal Issue 65 February 2026 - Flipbook - Page 60
This was a retrospective longitudinal cohort study
of implants placed by a single specialist periodontist
between 1995 and 2019.
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Although the maximum follow-up extended to over
22 years, the study does not clearly report how many
implants were actually observed beyond 15 years.
Many implants may only have been followed for a
short period.
Total implants: 10,871
Total patients: 4,247
Maximum follow-up: 22.2 years
Mean follow-up: 4.5 ± 4.2 years
The study used Kaplan–Meier survival
analysis, which:
Risk Factors Identi昀椀ed
The study reported higher implant failure rates in
the following groups:
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Patients with multiple implants compared to
single implants
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Heavy smokers
Patients with diabetes
Implants placed in grafted bone
Short implants (6 mm or less)
2.
Counts every failure event when it occurs.
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Treats patients who have not yet failed
(or who are lost to follow-up) as “censored”
rather than failures.
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Continuously updates survival probability
over time.
As long as some implants remain under observation
at later time points, the model can calculate longterm survival estimates, even if most implants were
followed for much shorter periods. This can result in
optimistic projections of long-term survival.
At 昀椀rst reading, this study may give the impression
that implants can reliably last up to 22 years or more.
However, there are important limitations:
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Wider Published Evidence
Other studies have reported that:
All implants were placed by a single specialist
operator, which is unusual in routine implant
dentistry and may overestimate success rates.
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Dental implants are not 100% successful and
there is a risk of failure within 10–15 years,
commonly due to peri-implantitis. Removal of a
failed implant can be traumatic and may result
in signi昀椀cant bone loss. Subsequent replacement
implants may need to be placed under more
di昀케cult clinical conditions (Setzer and Kim).
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All restorations require replacement cycles over
a patient’s lifetime (Holm-Pedersen).
The average implant follow-up period was
relatively short (mean 4.5 years), meaning that
relatively few implants were actually observed
for 15–20 years.
Actual Survival Versus Predicted Survival
The reported cumulative implant survival
rates were:
My Opinion
Based on the available evidence and my own clinical
experience:
A single implant can reasonably be expected
to last between 10 and 20 years, depending on
patient risk factors and maintenance.
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Implant-supported bridges are more di昀케cult
to keep clean and are subjected to increased
loading due to additional pontic teeth. Their
expected lifespan is therefore typically 10 to 15
years.
Having carried out implant surgery for over 30
years, my experience is that some implant failures
can occur early. Once an implant has successfully
integrated however, many remain functional for
20 years or more, although gradual bone loss and
implant exposure can occur over time.
• 3 years – 98.9%
• 5 years – 98.5%
• 10 years – 96.8%
• 15 years – 94%
For the purpose of costing future treatment:
I generally allow for replacement every 20 years in
patients without signi昀椀cant risk factors.
Cumulative survival represents a statistical estimate
of the probability that an implant survives to a given
time point, based on all available data.
EXPERT WITNESS JOURNAL
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FEBRUARY 2026
