1. Longevity of teeth and implants – a systematic review
C. TOMASI, J. L. WENNSTRO¨ M & T. BERGLUNDH Department of Periodontology, Institute of Odontology,
The Sahlgrenska Academy at Go¨teborg University, Go¨teborg, Sweden
SUMMARY The objective of this systematic review
was to describe the incidence of tooth and implant
loss reported in long-term studies. Prospective lon-
gitudinal studies reporting on teeth or implants
survival with a follow-up period of at least 10 years
were considered. Papers were excluded if the drop
out rate exceeded 30% or if <70% of the initial
subject sample was examined at 10 years of follow-
up. Seventy publications on teeth were identified as
potentially relevant for the focussed question. The
analysis of the abstracts yielded 37 studies eligible
for full-text analysis. The inclusion criteria were met
in 11 of the publications that included in all 3015
subjects. The initial search on implant studies gen-
erated 52 publications that possibly could be in-
cluded. Following the evaluation of the abstracts
and full-text analysis nine publications were found
to fulfil the inclusion criteria. The nine studies
included 476 subjects. The incidence of tooth loss
among subjects with a follow-up period of 10–
30 years varied from 1.3% to 5% in the majority of
studies, while in two epidemiological studies on
rural Chinese populations the incidences of tooth
loss were 14% and 20%. The percentage of implants
reported as lost during the follow-up period varied
between 1% and 18%. In clinically well-maintained
patients, the loss rate at teeth was lower than that at
implant. Bone level changes appeared to be small at
teeth as well as at implants in well-maintained
patients. Comparisons of the longevity at teeth and
dental implants are difficult due to heterogeneity
among the studies.
KEYWORDS: implants, longevity, teeth, prospective
study
Accepted for publication 4 November 2007
Introduction
Decision-making in treatment planning should be
based on scientific evidence. In the clinical situation
when deciding on either treating a tooth disorder or
extracting the tooth in favour of implant placement,
data that provide guidelines for the choice of strategy
are sparse. Although implant therapy is regarded as a
safe and reliable method in the treatment of complete
and partial edentulism, complications of technical and
biological nature occur (1). The ultimate complication
in implant therapy is the loss of implants, as for teeth
the extraction is the definitive failure. To determine the
longevity of teeth and implants, information on the
occurrence of these final events on a long-term basis
must be provided.
The objective of this systematic review was to
describe the incidence of tooth and implant loss
reported in prospective longitudinal studies with a
follow-up of at least 10 years. Alterations in marginal
bone support at teeth and implants were also
addressed.
Material and methods
Type of studies
Prospective longitudinal studies with a follow-up period
of at least 10 years were considered. Thus, cohort
studies, controlled clinical trials and randomized clinical
trials that provided data on tooth and ⁄or implant loss
over the indicated time period were analysed. Studies
reporting life-tables were analysed with respect to the
proportion of subjects or implants ⁄ teeth that were
followed ‡10 years. Publications were excluded if
<70% of the initial subject sample was examined at
ª 2008 The Authors. Journal compilation ª 2008 Blackwell Publishing Ltd doi: 10.1111/j.1365-2842.2007.01831.x
Journal of Oral Rehabilitation 2008 35 (Suppl. 1); 23–32

2. 10 years of follow-up, or if data corresponding to
10 years of observation could not be achieved. Studies
in which the rate of subject dropout at 10 years
exceeded 30% were also excluded.
Subjects
Subjects who were part of epidemiological studies or
enrolled in maintenance programmes of treatment
studies on teeth were included in the review. Implant-
related studies comprised edentulous and partially
edentulous subjects who were treated with endosseous
dental implants supporting fixed or removable recon-
structions. Studies that reported data on implant-tooth
connected prostheses were not included in the review.
Variables
Number and age of subjects included at baseline and
the number of subjects lost to follow-up were recorded.
The number of teeth present at baseline and the
number of installed implants were retrieved, as well
as the number of (i) teeth and implants lost during the
study and (ii) subjects who had experienced tooth or
implant loss. Data on marginal bone loss around teeth
and implants were also recorded.
Weighted mean values were calculated for the
number of teeth and implants at baseline and the
number ⁄ percentage of teeth and implants lost during
follow-up. For studies in which information on implant
loss was not clearly defined, the inverse of the cumu-
lative survival rate was calculated.
Search strategy
A search in PubMed was performed in May 2007 to
retrieve articles published in the English language. The
search terms used and the resulting matches were as
follows:
1 dental implants AND longitudinal studies (1664)
2 dental implants AND longitudinal (286)
3 dental implants AND clinical trial (810)
4 dental implants AND cohort studies (1677)
5 dental implants AND prospective studies (534)
6 dental implants AND survival (815)
7 dental implant AND longevity (54)
8 dental implants AND randomized clinical trial (314)
9 dental implants AND prospective (1713)
10 oral epidemiology AND tooth loss (434)
11 oral epidemiology AND longitudinal AND teeth
(149)
12 oral epidemiology AND periodontal disease (2344)
13 oral epidemiology AND caries (2843)
14 tooth loss AND prospective (361)
15 tooth loss AND cohort (138)
16 tooth loss AND longitudinal (200)
17 [‘Dental Health Surveys’ (Mesh)] AND tooth loss
(516)
18 [‘Dental Health Surveys’ (Mesh)] AND bone loss
(633)
19 [‘Dental Health Surveys’ (Mesh)] AND attachment
loss (958)
20 [‘Dental Health Surveys’ (Mesh)] AND implant loss
(197)
Manual search included bibliographies of previous
reviews and of selected publications. Furthermore, a
‘search for related articles’ in PubMed was applied for
all studies that were evaluated in full text.
Results
Teeth
From the screening of titles obtained from the database
search, 70 publications were identified as potentially
relevant for the focussed question. The evaluation of
abstracts yielded 37 studies eligible for full-text analysis.
11 publications met the inclusion criteria. The 26
excluded studies and the reasons for exclusion are
listed in Table 1.
The 11 included studies are presented in Table 2. Six
studies were epidemiological surveys of general popu-
lations (2–7), while three publications described sub-
jects who were classified as regular dental care
attendants (8–10). One study reported data from
institutionalized patients (11) and one study evaluated
subjects with untreated periodontitis (12). Three pub-
lications were grouped together as they reported on
findings from the same subject sample included in an
epidemiological survey (5–7). The follow-up period in
the 11 studies ranged between 10 and 30 years. In
several studies the data were reported according to age
categories and for these studies weighted mean values
were calculated. The age of the subjects at baseline
varied between 20 and 65 years. The total number of
subjects recorded at baseline in the 11 studies was 3015.
The number of subjects examined at the end of the
studies was 2304.
C . T O M A S I et al.24
ª 2008 The Authors. Journal compilation ª 2008 Blackwell Publishing Ltd

3. The mean number of teeth per subject at baseline was
reported in 10 of the studies and ranged from 21 to 26.
The incidence of tooth loss among subjects with a
follow-up period of 10–30 years varied from 1.3% to
5% in the majority of studies. Results presented in
epidemiological studies on rural Chinese population
samples, however, revealed an incidence of tooth loss
of 14–20% (2, 3). The proportion of individuals that
experienced tooth loss showed a range of 25–75% with
the highest figure in the studies on the Chinese
populations and in patients with untreated periodonti-
tis. Rosling et al. (2001) reported that the percentage of
subjects that experienced tooth loss was 64% for
patients with high susceptibility to periodontitis, while
among subjects with a ‘normal’ susceptibility the
corresponding figure was 26%. Main causes for tooth
extraction, when reported in the studies, were caries
and tooth fracture.
Data regarding marginal bone loss could be retrieved
from four studies, all from Sweden. The calculated
10-year rate of bone loss varied between 0.2 and
0.8 mm. For subjects who were evaluated in epidemi-
ological studies the corresponding figure was 0.6 mm.
Implants
The initial search generated 52 publications that possi-
bly could be included. Following the analysis of the
abstracts 39 of these studies were rejected. Hence, full-
text analysis was made in 23 studies, out of which nine
publications were found to fulfil the inclusion criteria.
The 14 excluded studies and the reasons for exclusion
are listed in Table 3.
The nine studies on implants included in this review
are reported in Table 4. The longest follow-up period
was 20 years. The age of the subjects at the time of
implant placement ranged between 18 and 80 years.
The overall number of subjects who received implants
was 476, while the number of subjects attending a final
examination was 355.
The majority of the studies reported data on
implants of the Bra˚nemark System. Four studies
reported data on implants placed in edentulous jaws
to support an overdenture (13–16) while other three
studies regarded implants placed in edentulous jaws to
support fixed prosthetic reconstructions (17–19). The
total number of implants placed in the nine studies
was 1460. The percentage of implants reported as lost
during the follow-up period varied between 1% and
18%. Only four studies presented information on the
number of subjects who had experienced implant loss.
The calculated proportion of such subjects in this
group of studies ranged between 3% and 29%. Causes
for implant loss were rarely reported. On the other
hand, the timing of implant loss was frequently
described. Between 9% and 100% of the implant loss
in the various studies were reported as ‘early loss’, i.e.
implants that were removed before the connection of
the prosthetic reconstruction.
Data on the amount of marginal bone loss over a
10-year period could be retrieved from eight studies.
In these studies the amount of bone loss was given in
mm per year or as a difference between the baseline
and the final follow-up examination. Most studies also
described the amount of bone loss that occurred
during the first year in function in addition to the
subsequent bone level alterations. The calculated 10-
year bone loss varied between 0.7 and 1.3 mm in the
available studies.
Table 1. Excluded publications on teeth and reasons for
exclusion
Reference Reason for exclusion
Ahlqwist et al. (1999) (20) % Subject drop
out >30%
Baljoon et al. (2005) (21) Same
Bergstro¨m et al. (2000)(22) Same
Bergstro¨m (2004) (23) Same
Burt et al. (1990) (24) Same
Ettinger & Qian (2004) (25) Same
Fure (2003) (26) Same
Halling & Bjo¨rn (1986) (27) Same
Hamalainen et al. (2004) (28) Same
Hiidenkari et al. (1997) (29) Same
Hujoel et al. (1999) (30) Same
Ismail et al. (1990) (31) Same
Jansson et al. (2002) (32) Same
Krall et al. (1999) (33) Same
Krall et al. (2006) (34) Same
Neely et al. (2005) (35) Same
Petersson et al. (2006) (36) Same
Rohner et al. (1983) (37) Same
Tezal et al. (2005) (38) Same
Warren et al. (2002) (39) Same
Fardal et al. (2004) (40) Same
Heitz-Mayfield et al. (2003) (41) Retrospective design
Scha¨tzle et al. (2003a), Scha¨tzle
et al. (2004), Scha¨tzle et al.
(2003b) (42–44)
Retrospective design
Eickholz et al. (2006) (45) Regenerative therapy
L O N G E V I T Y O F T E E T H A N D I M P L A N T S 25
ª 2008 The Authors. Journal compilation ª 2008 Blackwell Publishing Ltd

4. Table2.Prospectivestudiesonteeth
StudyFollow-upSubjectsampleAgerange
No.
subjects
Dropout
(deceased)
Meanno.
teethbaseline
Tooth
loss(%)
Subjects
exhibiting
toothloss
Bonelossin
10yearsCausesfortoothloss
Axelssonetal.
(2004)(8)
30yearsGeneralpopulation
Wellmaintained
20–65375118(49)24.83.6%NRNR62%Rootfracture
23%Endodontic
Baelumetal.
(1997)(2)
10yearsGeneral
Epidemiologic
China
20–60+58714725.520%75%NREndodonticOR3.9
Buckley&Crowley
(1984)(12)
10yearsUn-treated
periodontal
patients
15–5882NR14%Perio6%
Non-perio
61%NRNR
Chenetal.(2001)(3)10yearsMalesonly
Epidemiologic
China
20–5920023(5)25.714.1%NRNRPerio.breakdown
caries,endo
Gabreetal.
(1999)(11)
10yearsMentalretarded
Institution
41.0mean13621(19)20.717.9%NRNRNR
Norderydetal.
(1999)(5)
Hugoson&Laurell
(2000)(7)
Laurelletal.
(2003)(6)
17yearsGeneral
Epidemiologic
15–60574141(25)24.15%34%0.6mm58%Perio
36%Caries
Paulanderetal.
(2004)(4)
10yearsGeneral
Epidemiologic
50mean42912022.94.1%39%0.54mmCariesand
attachmentloss
predictorsof
toothloss
Roslingetal.
(2001)(9)
12yearsHighsusceptibility
Normal
susceptibility
45.5mean
41.8mean
109
225
61(9)
7
24.1
23.5
7.8%
1.3%
64%
26%
0.8mm
0.3mm
NR
Wennstro¨metal.
(1993)(10)
12yearsGeneral
population
Publicdental
clinic
18–6529873(8)23.73%25%0.2mmNR
OR,oddsratio.
C . T O M A S I et al.26
ª 2008 The Authors. Journal compilation ª 2008 Blackwell Publishing Ltd

5. Comparisons between teeth and implants
Due to the heterogeneity among the studies a meta-
analysis using statistical comparisons between teeth and
implants was not feasible. A graphic illustration of the
different studies on teeth and implants with regard to
the outcome of tooth ⁄ implant loss and the sample size
is presented in Fig. 1. Weighted mean values for loss
rates were calculated and plotted when data were
reported in subgroups. Tooth studies included larger
subject samples than studies on implants. The rate of
tooth and implant loss varied between as well as within
the two categories of studies.
Discussion
In the present systematic review the longevity of teeth
and dental implants was described. Comparisons
between long-term investigations on teeth and im-
plants, however, are difficult due to the differences in
the subjects included and the overall lack of implant
studies employing an epidemiological approach in
study design. Thus, implant publications in the current
review were in general longitudinal cohort studies of
well-defined groups of subjects who all received
implant therapy. In other words, the evaluation in this
category of studies was confined to a distinct group of
subjects who required a certain treatment of partial or
complete edentulism. The character of tooth studies, on
the other hand, was in most cases entirely different.
Although well-maintained groups of subjects were
included in some studies, many of the included studies
on teeth in the present review comprised ‘untreated’
subjects who did not receive appropriate regular main-
tenance. In addition, the epidemiological approach that
was employed in several studies provided a sample
representing a general population, while in other
studies the participants exhibited varying susceptibility
to periodontitis. The differences in the character of
tooth- and implant studies must, therefore, be consid-
ered in the comparisons of longevity criteria.
Many publications that were identified in the Pub-
Med search fulfilled the criteria of 10 years of follow-up
but were excluded from the evaluation due to other
grounds. The most common reason for not including
such a study on teeth in the present review was the rate
of subject dropouts that exceeded 30%. This feature is a
frequent problem in epidemiological research using
large population samples. The reasons for excluding
implant studies of 10 years of follow-up were different.
This finding may be explained by the variations in study
character and subject sample between tooth- and
implant studies as discussed above.
One particular problem in the evaluation of studies to
be eligible for the present review was the question
whether the longitudinal study applied a prospective or
retrospective design. The decision taken in this review
to describe the longevity of teeth and dental implants
prompted the selection of prospective studies. In several
identified publications during the search, the study
design was clearly stated and described, while in other
reports the description of the study methods raised
doubts with regard to the use of a prospective or
retrospective design. A retrospective design was the
common reason for excluding studies on both teeth and
implants.
The main outcome variable that was evaluated in the
current review was tooth- and implant loss. The
incidence of tooth loss varied considerably. Thus, in
one study on an untreated old rural population in
China (2) the loss rate was 20%, while in an epidemi-
ological study on a general population in China tooth
loss occurred in 14% (3). A third investigation that
reported a mean tooth loss rate that amounted to 18%
was performed in a small cohort of patients institution-
Table 3. Excluded publications on implants and reasons for
exclusion
Authors ⁄ year Reason for exclusion
Jemt & Johansson (2006) (46) % subject drop out >30%
Attard & Zarb (2003) (47) Retrospective design
Merickse-Stern et al.
(2001) (48)
Retrospective design
Naert et al. (2000) (49) <80% of subjects at 10 years
follow-up
Hultin et al. (2000) (50) Subgroup of (51)
Bra¨gger et al. (2005) (52) Connection teeth-implants
Gunne et al. (1999) (53) Connection teeth-implants
Yanase et al. (1994) (54) Non-endosseous implants
Nystro¨m et al. (2004) (55) Bone grafting before implant
placement
Roos-Jansa˚ker et al.
(2006) (56)
Cross-sectional with
retrospective analysis
Willer et al. (2003) (57) Unclear design and description
of the study lacking
information
Attard & Zarb (2004a) (17) Retrospective design
Attard & Zarb (2004b) (13) Retrospective design
Zarb & Zarb (2002) (58) Retrospective design
L O N G E V I T Y O F T E E T H A N D I M P L A N T S 27
ª 2008 The Authors. Journal compilation ª 2008 Blackwell Publishing Ltd

6. Table4.Prospectivestudiesonimplants
Study
Follow-
up
Subject
sampleAgerange
No.
subjects
Dropout
(deceased)
No.
implants
placed
Implant
type
Implant
loss
Timingof
implantloss
Subjects
exhibiting
implant
loss(%)
Bonelosson
10years
Deporteretal.
(2002)(14)
10yearsEdentulous
Overdenture
56mean529(6)156Endopore8%9%earlyloss15%0.71mm
Ekelundetal.
(2003)(18)
Carlssonetal.
2000(59)
Lindquistetal.
1996(60)
20yearsEdentulous
Fixed
33–64473(2)at
15years
17(6)at
20years
273Bra˚nemark1%66%earlylossNR0.9mm
Karoussisetal.
(2004)(61)
10yearsPeriodontal
patients
19–7812738(9)179ITI7.3%NRNR0.74mm
9yearsdata
Lekholmetal.
(1999)(51)
10yearsPartially
edentulous
18–7012738(5)461Bra˚nemark10%76%earlyloss29%0.7mm
Meijeretal.
(2004)(15)
10yearsEdentulous
Overdenture
57mean29
32
1
7(4)
58
61
IMZ
Bra˚nemark
7.1%
18%
75%earlyloss
55%earlyloss
10%
20%
NR
Naertetal.
(2004)(16)
10yearsEdentulous
Overdenture
36–853610(9)73Bra˚nemark2%100%earlyloss3%0.86mm
Rasmussonetal.
(2005)(19)
10yearsEdentulous
Fixed
50–80368(3)199Astra3.9%100%earlylossNR1.3mm
7yearsdata
ITI,Straumanndentalimplants.
C . T O M A S I et al.28
ª 2008 The Authors. Journal compilation ª 2008 Blackwell Publishing Ltd

7. alized for mental disease (11). Thus, the three studies
referred to represent subject samples that may not be
comparable to those reported in the implant studies of
the present review. Furthermore, in the studies involv-
ing Scandinavian populations the 10-year rate of tooth
loss was below 5%.
Moreover the incidence of implant loss varied. While
most implant studies presented loss rates <10% (62),
few publications contained data on 17–18% lost
implants. It is evident that a major part of the number
of lost implants reported occurred between the implant
installation and before the connection of the supra-
structure. Three studies reported on implants support-
ing overdenture type reconstructions (13–16), which
pooled together did not present higher loss rates than
other studies reported. The finding is in contrast with
the data presented in a previous systematic review on
biological and technical complications in implant ther-
apy (1). In this review it was concluded that the
incidence of implant loss in overdenture therapy was
twice as high as that when using fixed reconstructions
on implants. In one study in the current review two
different implant systems were compared using a
randomized controlled clinical trial design (15). The
subjects that were included received an overdenture
supported by two implants of either IMZ or Bra˚nemark
implants. A significantly larger probing depth for IMZ
implants was reported at the 1-year and 10-year
examinations. The incidence of implants loss at
10 years, however, was twice as high in Bra˚nemark
implants as in IMZ implants.
Marginal bone loss was not considered as a suitable
variable for meta-analysis due to the heterogeneity of
data that was reported. For teeth, such data were
frequently lacking and also in the case when data on
bone loss were obtained from attachment level mea-
surements, results were presented either in mm ⁄year
or in total mm for the follow-up period. In one study
with long follow-up and more strict maintenance, a
gain in attachment levels at the end of observation
period was reported. It is interesting to note that there
was no apparent relation between marginal bone loss
and the rate of tooth loss rate. The problem of
heterogeneity of data was more pronounced in studies
on implants than in studies on teeth. The use of mean
bone loss at the subject level may hide the presence of
an implant or a tooth presenting pathological bone
loss. Another important consideration in the compar-
ison of the longevity of teeth and dental implants is
the fact that the number of years in service for teeth is
much larger than that of implants despite the study
design of similar follow-up periods. Thus, in a 40-year-
old subject who is enrolled in a longitudinal study, the
teeth have already history of about 30 years of service.
The corresponding function period for an implant,
however, will commence at the time of implant
installation. A further comment to the data obtained
from the implant studies in the present review is the
fact that the types of implants that were evaluated are
no longer available. The requested follow-up docu-
mentation for implants that are currently in use
appears to be lacking. Finally, it must be realized that
Tooth ( ) vs. Implant ( ) Loss
Rosling 2001
Paulander 2004
Norderyd 1999
Chen 2001
Baelum 1997
Rosling 2001
Axelsson 2004
Wennström 1993
Buckley 1984
Gabre 1999
Ekelund 2003
Naert 2004
Rasmusson 2005
Karoussis 2004
Deporter 2002
Lekholm 1999
Meijer 2004
Meijer 2004
0
5
10
15
20
25
0 100 200 300 400 500
No. of subjects followed
%loss
Fig. 1. Rate of tooth and implant
loss in relation to subject sample.
L O N G E V I T Y O F T E E T H A N D I M P L A N T S 29
ª 2008 The Authors. Journal compilation ª 2008 Blackwell Publishing Ltd

8. in studies on teeth the subjects may exhibit varying
systemic and local compromising conditions, while
studies on implants in most cases demonstrate ideal
conditions regarding subject selection and situation of
oral tissues.
Conclusions
1 In clinically well-maintained patients, the survival
rates of teeth were higher than that of implants.
2 In well-maintained patients, the bone level
changes appeared to be small at teeth as well as
at implants.
3 Comparisons of the longevity of teeth and dental
implants are difficult due to marked heterogeneity
among the studies. Thus, in most implant studies the
subjects were selected for a dedicated treatment
procedure, while in studies on teeth most the
conditions that existed for a random population were
described (epidemiological study).
4 The number of subjects evaluated in studies on teeth
was considerably larger than that in studies on
implants.
Conflicts of interest
The authors declare no conflicts of interests.
References
1. Berglundh T, Persson L, Klinge B. A systematic review of the
incidence of biological and technical complications in implant
dentistry reported in prospective longitudinal studies of at
least 5 years. J Clin Periodontol. 2002;29 ((Suppl. 1)Suppl.
3):197–212.
2. Baelum V, Luan WM, Chen X, Fejerskov O. Predictors of
tooth loss over 10 years in adult and elderly Chinese.
Community Dent Oral Epidemiol. 1997;25:204–210.
3. Chen X, Wolff L, Aeppli D, Guo Z, Luan W, Baelum V et al.
Cigarette smoking, salivary ⁄ gingival crevicular fluid cotinine
and periodontal status. A 10-year longitudinal study. J Clin
Periodontol. 2001;28:331–339.
4. Paulander J, Axelsson P, Lindhe J, Wennstro¨m J. Intra-oral
pattern of tooth and periodontal bone loss between the age of
50 and 60 years. A longitudinal prospective study. Acta
Odontol Scand. 2004;62:214–222.
5. Norderyd O¨ , Hugoson A, Grusovin G. Risk of severe peri-
odontal disease in a Swedish adult population. A longitudinal
study. J Clin Periodontol. 1999;26:608–615.
6. Laurell L, Romao C, Hugoson A. Longitudinal study on the
distribution of proximal sites showing significant bone loss.
J Clin Periodontol. 2003;30:346–352.
7. Hugoson A, Laurell L. A prospective longitudinal study on
periodontal bone height changes in a Swedish population.
J Clin Periodontol. 2000;27:665–674.
8. Axelsson P, Nystro¨m B, Lindhe J. The long-term effect of a
plaque control program on tooth mortality, caries and
periodontal disease in adults. Results after 30 years of main-
tenance. J Clin Periodontol. 2004;31:749–757.
9. Rosling B, Serino G, Hellstro¨m MK, Socransky SS, Lindhe J.
Longitudinal periodontal tissue alterations during supportive
therapy. Findings from subjects with normal and high
susceptibility to periodontal disease. J Clin Periodontol.
2001;28:241–249.
10. Wennstro¨m JL, Serino G, Lindhe J, Eneroth L, Tollskog G.
Periodontal conditions of adult regular dental care attendants.
A 12-year longitudinal study. J Clin Periodontol.
1993;20:714–722.
11. Gabre P, Martinsson T, Gahnberg L. Incidence of, and
reasons for, tooth mortality among mentally retarded adults
during a 10-year period. Acta Odontol Scand. 1999;57:55–
61.
12. Buckley LA, Crowley MJ. A longitudinal study of untreated
periodontal disease. J Clin Periodontol. 1984;11:523–530.
13. Attard NJ, Zarb GA. Long-term treatment outcomes in
edentulous patients with implant overdentures: the Toronto
study. Int J Prosthodont. 2004a;17:425–433.
14. Deporter D, Watson P, Pharoah M, Todescan R, Tomlinson G.
Ten-year results of a prospective study using porous-surfaced
dental implants and a mandibular overdenture. Clin Implant
Dent Relat Res. 2002;4:183–189.
15. Meijer HJ, Raghoebar GM, Van’t Hof MA, Visser A. A
controlled clinical trial of implant-retained mandibular over-
dentures: 10 years’ results of clinical aspects and aftercare of
IMZ implants and Branemark implants. Clin Oral Implants
Res. 2004;15:421–427.
16. Naert I, Alsaadi G, van Steenberghe D, Quirynen M. A 10-year
randomized clinical trial on the influence of splinted and
unsplinted oral implants retaining mandibular overdentures:
peri-implant outcome. Int J Oral Maxillofac Implants.
2004;19:695–702.
17. Attard NJ, Zarb GA. Long-term treatment outcomes in
edentulous patients with implant-fixed prostheses: the Tor-
onto study. Int J Prosthodont. 2004b;17:417–424.
18. Ekelund JA, Lindquist LW, Carlsson GE, Jemt T. Implant
treatment in the edentulous mandible: a prospective study on
Branemark system implants over more than 20 years. Int J
Prosthodont. 2003;16:602–608.
19. Rasmusson L, Roos J, Bystedt H. A 10-year follow-up study of
titanium dioxide-blasted implants. Clin Implant Dent Relat
Res. 2005;7:36–42.
20. Ahlqwist M, Bengtsson C, Hakeberg M, Hagglin C. Dental
status of women in a 24-year longitudinal and cross-sectional
study. Results from a population study of women in Goteborg.
Acta Odontol Scand. 1999;57:162–167.
21. Baljoon M, Natto S, Bergstro¨m J. Long-term effect of smoking
on vertical periodontal bone loss. J Clin Periodontol.
2005;32:789–797.
C . T O M A S I et al.30
ª 2008 The Authors. Journal compilation ª 2008 Blackwell Publishing Ltd

9. 22. Bergstro¨m J, Eliasson S, Dock J. A 10-year prospective study
of tobacco smoking and periodontal health. J Periodontol.
2000;71:1338–1347.
23. Bergstro¨m J. Influence of tobacco smoking on periodontal
bone height. Long-term observations and a hypothesis. J Clin
Periodontol. 2004;31:260–266.
24. Burt BA, Ismail AI, Morrison EC, Beltran ED. Risk factors for
tooth loss over a 28-year period. J Dent Res. 1990;69:1126–
1130.
25. Ettinger RL, Qian F. Abutment tooth loss in patients with
overdentures. J Am Dent Assoc. 2004;135:739–746; quiz 795–
736.
26. Fure S. Ten-year incidence of tooth loss and dental caries in
elderly Swedish individuals. Caries Res. 2003;37:462–469.
27. Halling A, Bjo¨rn AL. Periodontal status in relation to age of
dentate middle aged women. A 12 year longitudinal and a
cross-sectional population study. Swed Dent J. 1986;10:233–
242.
28. Hamalainen P, Meurman JH, Keskinen M, Heikkinen E.
Changes in dental status over 10 years in 80-year-old people:
a prospective cohort study. Community Dent Oral Epidemiol.
2004;32:374–384.
29. Hiidenkari T, Parvinen T, Helenius H. Edentulousness and its
rehabilitation over a 10-year period in a Finnish urban area.
Community Dent Oral Epidemiol. 1997;25:367–370.
30. Hujoel PP, Lo¨e H, Anerud A, Boysen H, Leroux BG. The
informativeness of attachment loss on tooth mortality.
J Periodontol. 1999;70:44–48.
31. Ismail AI, Morrison EC, Burt BA, Caffesse RG, Kavanagh MT.
Natural history of periodontal disease in adults: findings from
the Tecumseh Periodontal Disease Study, 1959–87. J Dent
Res. 1990;69:430–435.
32. Jansson L, Lavstedt S, Zimmerman M. Marginal bone loss and
tooth loss in a sample from the County of Stockholm – a
longitudinal study over 20 years. Swed Dent J. 2002;26:21–
29.
33. Krall EA, Garvey AJ, Garcia RI. Alveolar bone loss and tooth
loss in male cigar and pipe smokers. J Am Dent Assoc.
1999;130:57–64.
34. Krall EA, Dietrich T, Nunn ME, Garcia RI. Risk of tooth loss
after cigarette smoking cessation. Prev Chronic Dis.
2006;3:A115.
35. Neely AL, Holford TR, Loe H, Anerud A, Boysen H. The
natural history of periodontal disease in humans: risk factors
for tooth loss in caries-free subjects receiving no oral health
care. J Clin Periodontol. 2005;32:984–993.
36. Petersson K, Pamenius M, Eliasson A, Narby B, Holender F,
Palmqvist S et al. 20-year follow-up of patients receiving
high-cost dental care within the Swedish Dental Insurance
System: 1977–1978 to 1998–2000. Swed Dent J. 2006;30:77–
86.
37. Rohner F, Cimasoni G, Vuagnat P. Longitudinal radiograph-
ical study on the rate of alveolar bone loss in patients of a
dental school. J Clin Periodontol. 1983;10:643–651.
38. Tezal M, Wactawski-Wende J, Grossi SG, Dmochowski J,
Genco RJ. Periodontal disease and the incidence of tooth loss in
postmenopausal women. J Periodontol. 2005;76:1123–1128.
39. Warren JJ, Watkins CA, Cowen HJ, Hand JS, Levy SM, Kuthy
RA. Tooth loss in the very old: 13–15-year incidence among
elderly Iowans. Community Dent Oral Epidemiol.
2002;30:29–37.
40. Fardal O, Johannessen AC, Linden GJ. Tooth loss during
maintenance following periodontal treatment in a peri-
odontal practice in Norway. J Clin Periodontol. 2004;31:
550–555.
41. Heitz-Mayfield LJ, Scha¨tzle M, Loe H, Burgin W, Anerud A,
Boysen H et al. Clinical course of chronic periodontitis. II.
Incidence, characteristics and time of occurrence of the
initial periodontal lesion.. J Clin Periodontol. 2003;30:902–
908.
42. Scha¨tzle M, Lo¨e H, Burgin W, Anerud A, Boysen H, Lang NP.
Clinical course of chronic periodontitis. I. Role of gingivitis.
J Clin Periodontol. 2003a;30:887–901.
43. Scha¨tzle M, Lo¨e H, Lang NP, Burgin W, Anerud A, Boysen H.
The clinical course of chronic periodontitis. J Clin Periodontol.
2004;31:1122–1127.
44. Scha¨tzle M, Lo¨e H, Lang NP, Heitz-Mayfield LJ, Burgin W,
Anerud A et al. Clinical course of chronic periodontitis. III.
Patterns, variations and risks of attachment loss. J Clin
Periodontol. 2003b;30:909–918.
45. Eickholz P, Pretzl B, Holle R, Kim TS. Long-term results of
guided tissue regeneration therapy with non-resorbable and
bioabsorbable barriers. III. Class II furcations after 10 years.
J Periodontol. 2006;77:88–94.
46. Jemt T, Johansson J. Implant treatment in the edentulous
maxillae: a 15-year follow-up study on 76 consecutive
patients provided with fixed prostheses. Clin Implant Dent
Relat Res. 2006;8:61–69.
47. Attard NJ, Zarb GA. Implant prosthodontic management of
partially edentulous patients missing posterior teeth: the
Toronto experience. J Prosthet Dent. 2003;89:352–359.
48. Merickse-Stern R, Aerni D, Geering AH, Buser D. Long-term
evaluation of non-submerged hollow cylinder implants. Clin-
ical and radiographic results. Clin Oral Implants Res.
2001;12:252–259.
49. Naert I, Koutsikakis G, Duyck J, Quirynen M, Jacobs R, van
Steenberghe D. Biologic outcome of single-implant restora-
tions as tooth replacements: a long-term follow-up study. Clin
Implant Dent Relat Res. 2000;2:209–218.
50. Hultin M, Gustafsson A, Klinge B. Long-term evaluation of
osseointegrated dental implants in the treatment of partly
edentulous patients. J Clin Periodontol. 2000;27:128–133.
51. Lekholm U, Gunne J, Henry P, Higuchi K, Linden U,
Bergstrom C et al. Survival of the Branemark implant in
partially edentulous jaws: a 10-year prospective multicenter
study. Int J Oral Maxillofac Implants. 1999;14:639–645.
52. Bragger U, Karoussis I, Persson R, Pjetursson B, Salvi G, Lang
N. Technical and biological complications ⁄ failures with single
crowns and fixed partial dentures on implants: a 10-year
prospective cohort study. Clin Oral Implants Res.
2005;16:326–334.
53. Gunne J, A˚ strand P, Lindh T, Borg K, Olsson M. Tooth-
implant and implant supported fixed partial dentures: a 10-
year report. Int J Prosthodont. 1999;12:216–221.
L O N G E V I T Y O F T E E T H A N D I M P L A N T S 31
ª 2008 The Authors. Journal compilation ª 2008 Blackwell Publishing Ltd

10. 54. Yanase RT, Bodine RL, Tom JF, White SN. The mandibular
subperiosteal implant denture: a prospective survival study.
J Prosthet Dent. 1994;71:369–374.
55. Nystrom E, Ahlqvist J, Gunne J, Kahnberg KE. 10-year follow-
up of onlay bone grafts and implants in severely resorbed
maxillae. Int J Oral Maxillofac Surg. 2004;33:258–262.
56. Roos-Jansa˚ker AM, Lindahl C, Renvert H, Renvert S. Nine- to
fourteen-year follow-up of implant treatment. Part I: implant
loss and associations to various factors. J Clin Periodontol.
2006;33:283–289.
57. Willer J, Noack N, Hoffmann J. Survival rate of IMZ implants:
a prospective 10-year analysis. J Oral Maxillofac Surg.
2003;61:691–695.
58. Zarb JP, Zarb GA. Implant prosthodontic management of
anterior partial edentulism: long-term follow-up of a prospec-
tive study. J Can Dent Assoc. 2002;68:92–96.
59. Carlsson GE, Lindquist LW, Jemt T. Long-term marginal
periimplant bone loss in edentulous patients. Int J Prosth-
odont. 2000;13:295–302.
60. Lindquist LW, Carlsson GE, Jemt T. A prospective 15-year
follow-up study of mandibular fixed prostheses supported by
osseointegrated implants. Clinical results and marginal bone
loss. Clin Oral Implants Res. 1996;7:329–336.
61. Karoussis IK, Bragger U, Salvi GE, Burgin W, Lang NP.
Effect of implant design on survival and success rates of
titanium oral implants: a 10-year prospective cohort study
of the ITI Dental Implant System. Clin Oral Implants Res.
2004;15:8–17.
62. Pjetursson B, Lang NP. Prosthetic treatment planning on the
basis of scientific evidence. J Oral Rehabil. 2008;35(Suppl. 1):
72–79.
Correspondence: Cristiano Tomasi, Department of Periodontology,
Institute of Odontology, The Sahlgrenska Academy at Go¨teborg
University, Box 450 SE 405 30 Go¨teborg, Sweden.
E-mail: cristiano.tomasi@odontologi.gu.se
C . T O M A S I et al.32
ª 2008 The Authors. Journal compilation ª 2008 Blackwell Publishing Ltd