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Transcript of Web viewWORD COUNT. 3920. CONFLICT OF INTERESTS AND SOURCE OF FUNDING. ... a retrospective study of...
Submission to Journal of Clinical Periodontology (accepted version)
TITLE
Alterations in soft tissue levels and aesthetics over a 16 to 22 year period following single
implant treatment in periodontally-healthy patients: a retrospective case series
RUNNING TITLE
Long term soft tissue alterations
KEY WORDS
Dental implant, single tooth, soft tissue, recession, infra-position, eruption, aesthetics, long
term
AUTHORS
Dierens, M., De Bruecker, E., Vandeweghe, S., Kisch, J., De Bruyn, H., Cosyn, J.
AFFILIATIONS AND INSTITUTIONS
Melissa Dierens1, Evelyn De Bruecker1, Stefan Vandeweghe1,2, Jëno Kisch3, Hugo De Bruyn1,2,
Jan Cosyn1,4
1University of Ghent, Faculty of Medicine and Health Sciences, Dental School, Department of
Periodontology and Oral Implantology, De Pintelaan 185, B-9000 Ghent, Belgium2Malmö University, Department of Prosthetic Dentistry, Carl Gustafsväg, SE-20506 Malmö,
Sweden3Clinic for Prosthodontics, Centre of Dental Specialist Care, Spårvägsgatan 12, SE-21427
Malmö, Sweden4Free University of Brussels (VUB), Faculty of Medicine and Pharmacy, Dental Medicine,
Laarbeeklaan 103, B-1090 Brussels, Belgium
CONTACT ADDRESS CORRESPONDING AUTHOR
Jan Cosyn
University of Ghent, Faculty of Medicine and Health Sciences, Dental School, Department of
Periodontology and Oral Implantology, De Pintelaan 185, B-9000 Ghent, Belgium
1
E-mail: [email protected]
WORD COUNT
3920
CONFLICT OF INTERESTS AND SOURCE OF FUNDING
The authors declare they have no conflict of interests. The study was supported by the
Department of Periodontology and Oral Implantology of the University in Ghent and
Folktandvården, Region Skåne, Sweden.
AbstractPurpose: Long term studies on single implants are scarce and merely focus on clinical
response parameters, complications and bone remodelling. The objective of this
retrospective case series was to assess alterations in soft tissue levels and aesthetics over a
16 to 22 year period in periodontally-healthy patients.
Material and methods: Patients who had received a single turned implant in the anterior
maxilla/mandible at the Dental Specialist Clinic in Malmö between 1987 and 1993 were
invited for a re-examination on the basis of a number of inclusion criteria. Both neighbouring
teeth had to be present at re-examination and baseline clinical photographs (within the first
year of function) had to be available for soft tissue evaluation. These photographs were
superimposed onto final clinical photographs to assess longitudinal soft tissue alterations.
Results: Twenty-one patients (9 females; mean age 23, range 16-41) treated with 24 single
implants met the criteria for soft tissue evaluation. Peri-implant soft tissue levels (papillae,
midfacial level) remained stable over a 16 to 22 year observation period (p ≥ 0.372).
However, neighbouring teeth demonstrated midfacial recession and eruption pointing to a
major distortion with the implant crown (> 1 mm) in 5/24 (21 %) and 10/24 (42 %) of the
cases, respectively. Baseline aesthetics was considered poor (mean Pink Esthetic Score 7.42,
mean White Esthetic Score 5.43), yet a significant time effect could not be demonstrated (p
≥ 0.552). Implant and tooth bone loss was low (mean 0.6 mm and 0.4 mm, respectively) over
a 16 to 22 year period.
2
Conclusions: This limited case series demonstrated stable peri-implant soft tissue levels and
aesthetics in the long term following single implant treatment in periodontally-healthy
patients. However, midfacial recession and eruption may be expected at neighbouring teeth.
Clinical relevanceScientific rationale: There are no long term studies on single implant treatment with
longitudinal data on soft tissue levels and aesthetics.
Principal findings: This limited case series of 21 patients demonstrated stable peri-implant
soft tissue levels and aesthetics over a 16 to 22 year period following single implant
treatment in periodontally-healthy patients. However, midfacial recession and eruption may
be expected at neighbouring teeth.
Practical implications: In the long term disparities between implant restorations and
neighbouring teeth may be expected in terms of soft tissue and incisal levels.
3
IntroductionImplant treatment has become a viable option in contemporary practice to restore a single
tooth gap (Cosyn et al. 2012b). According to a number of systematic reviews this concept is
predictable and successful (Creugers et al. 2000, Berglundh et al. 2002, den Hartog et al.
2008, Jung et al. 2008). However, this statement should be interpreted in the context of
important limitations relating to study duration and registered parameters. In this respect,
clinical studies on single implants with observation periods of 15 years or longer are scarce
and merely focus on clinical response parameters, complications and bone remodelling
(Jemt 2008, Bergenblock et al. 2010, Dierens et al. 2012). Still, contemporary practice shows
that patients mainly judge the outcome of a single implant on aesthetic aspects. This
evolution may explain the growing interest by scientists for soft tissue dynamics, objective
aesthetic ratings and patient-reported outcomes in the last 5 years. At least in the short
term, ample studies have shown that midfacial recession may be expected following single
implant treatment, whereas papillae tend to regrow usually filling up the embrasure space
to an acceptable extent (Grunder 2000, Henriksson & Jemt 2004, Cardaropoli et al. 2006,
Juodzbalys & Wang 2007, Lai et al. 2008, Chen et al. 2009, Cosyn et al. 2011, Buser et al.
2011, den Hartog et al. 2011, Gallucci et al. 2011a, Raes et al. 2011). Albeit midfacial soft
tissue level and papillae are key factors for aesthetic success, the latter is influenced by many
other parameters of which most are probably taken into account in novel indices (Fürhauser
et al. 2005, Meijer et al. 2005, Belser et al. 2009). On the basis of these objective scoring
methods, it seems that the aesthetic outcome of single implant treatment lacks
predictability given aesthetic failure rates up to about one third of the cases (Juodzbalys &
Wang 2007, Meijndert et al. 2007, Lai et al. 2008, Belser et al. 2009, Chen et al. 2009, Cosyn
et al. 2010, 2011, 2012a, Buser et al. 2011, den Hartog et al. 2011, Gallucci et al. 2011b, Raes
et al. 2011). A demanding protocol in well-selected patients has been evaluated in a
prospective study and may overcome this (Cosyn et al. 2012a), yet such protocols may
probably not reflect daily clinical practice. In this respect, retrospective studies may add
relevant information to what can be expected on a routine basis. The objective of this
retrospective case series was to document alterations in soft tissue levels and aesthetics
over a 16 to 22 year period following single implant treatment in periodontally-healthy
patients.
4
Material and methodsPatient selection
This retrospective case series was based on data from periodontally-healthy patients who
were clinically re-examined 16 to 22 years following single implant treatment at the Centre
of Dental Specialist Care, Malmö, Sweden. Patients were invited for a re-examination if they
met the following inclusion criteria according to their records:
Single implant treatment in the anterior maxilla (15-25) or mandible (45-35) using the
Brånemark Implant System (Nobelpharma AB, Göteborg, Sweden) with a turned
surface and externally hexed implant-abutment connection between 1987 and 1993.
Presence of both neighbouring teeth.
Availability of peri-apical radiographs.
At least one control visit following crown installation.
The clinical and radiographic outcome of this case series can be found in a recent paper
(Dierens et al. 2012). Given the objective of this study focusing on soft tissue aspects of
treatment outcome, the following inclusion criteria had to be additionally fulfilled:
Presence of both neighbouring teeth and the contra-lateral tooth in case of incisor or
cuspid replacements at re-examination.
Availability of baseline clinical photographs (within the first year of function) of the
implant restoration.
The protocol was approved by the Regional Ethical Review Board in Lund and all patients
signed an informed consent.
Surgical and restorative procedures
At least 6 months following tooth removal, implants were placed according to a classical
two-stage procedure (Brånemark et al. 1977, Adell et al. 1981, Jemt et al. 1986). This
included standard flap elevation, bone preparation including countersinking, implant
installation in a strict palatal position, application of a cover screw and primary wound
closure. Abutment connection was performed after no less than 3 months of
osseointegration. Bone augmentation was never performed nor before implant surgery,
neither at the time of implant placement. Given the developmental stage of implant
5
prosthetics in the eighties, several prosthetic designs requiring various technical procedures
were included. Impression taking was performed at implant level or abutment level for
customized or CeraOneTM abutments, respectively. Customized abutments were fixed with a
titanium screw, whereas CeraOneTM abutments were fixed with a gold screw. Implant crowns
were placed in occlusal contact, but out of articulation to prevent overload. Full-ceramic or
acrylic/porcelain-fused-to-metal gold crowns were cemented onto individually customized
abutments or CeraOneTM abutments. The initial follow-up was performed in the Dental
Specialist Clinic.
Examination criteria
The clinical and radiographic outcome of this case series can be found in a recent paper
(Dierens et al. 2012). The present report adds new information on this patient sample
focusing on soft tissue aspects of treatment outcome. Alterations over time in soft tissue
levels and aesthetic parameters were considered primary outcome variables. Clinical and
radiographic parameters were considered secondary outcome variables.
Soft tissue levels
Baseline clinical photographs were digitized using designated software (Super Coolscan 4000
ED, Nikon, Tokyo, Japan; Photo Station, Albumprinter, Amsterdam, The Netherlands). These
were superimposed onto the final digital photographs using photo-editing software
(Photoshop, version CS5, San Jose, California, USA) based on the best fit of the implant
crown. During the clinical re-examination the clinical crown length of the implant
restoration, i.e. the total length of the restoration visible in the mouth including possible
recession, was measured intra-orally using a calliper. This distance was used to calibrate
both photographs. First, horizontal parallel lines at the level of the incisal plane and midfacial
soft tissue level were drawn onto the final clinical photograph (fig. 1). Then, these lines were
projected onto the baseline clinical photograph after superimposing both photographs.
Given the known distance between the horizontal lines, the following linear measurements
could be recorded:
Clinical implant crown length at baseline and at re-examination.
Clinical tooth crown length at baseline and re-examination for the best visible
neighbouring tooth.
6
Mesial papilla height at baseline and re-examination.
Distal papilla height at baseline and re-examination.
Aforementioned measurements were performed by one clinician (EDB) using an image
processing program (Image J, Bethesda, Maryland, USA). Recordings were repeated by the
same clinician after an interval of 6 weeks in order to evaluate intra-assessor reliability.
At the best visible neighbouring tooth midfacial recession and eruption were assessed giving
a score of 0, 1 or 2 with 0 representing no change, 1 representing minor change (≤ 1mm) and
2 representing major change (> 1mm) between baseline and re-examination. The gingival
horizontal line for calibration was used as a reference for recession evaluation, whereas the
incisal plane of the implant crown was used as a reference for evaluating eruption of the
neighbouring tooth. For the latter it was assumed that the incisal plane of the implant crown
remained unchanged over a 16 to 22 year period.
(HERE APPROXIMATELY FIGURE 1 & 2 PLEASE)
Aesthetic parameters
The aesthetic outcome was assessed at baseline and re-examination on the basis of the Pink
Esthetic Score (Fürhauser et al. 2005) and White Esthetic Score (Belser et al. 2009). The PES
is based on 7 criteria: mesial papilla, distal papilla, soft tissue level, contour, alveolar process
deficiency, colour and texture. Each of these parameters is assessed giving a score of 0, 1 or
2 with 0 representing the poorest outcome and 2 representing a perfect outcome. Papillae
are evaluated for completeness whereas the other variables are scored by comparing with a
reference tooth, which is the contralateral tooth for incisor and cuspid replacements and the
neighbouring premolar for premolar replacements. As proposed by Cosyn et al. (2010) a
total score ≤ 7 was considered aesthetic failure, whereas a total score ≥ 12 was considered
(almost) perfect outcome.
The WES is based on 5 criteria focusing on the visible part of the restoration. Tooth form,
volume, colour, texture and translucency are scored in a similar way as the criteria of the
PES. As proposed by Cosyn et al. (2010) a total score ≤ 5 was considered aesthetic failure,
whereas a total score ≥ 9 was considered (almost) perfect outcome. All clinical photographs
were scored twice by the same clinician (EDB) with an interval of 6 weeks in order to
evaluate intra-assessor reliability.
7
Clinical and radiographic parameters
At re-examination a peri-apical radiograph was taken using the long cone parallel technique
to evaluate implant bone level using the implant-abutment interface as a reference point.
The distance between this point and the first visible bone-to-implant contact was measured
at both sides of the implant. Baseline radiographs taken within 6 months after abutment
connection were digitized and analysed likewise by an independent examiner (RP) calibrating
on the known distance between the implant threads. Implant bone loss was calculated as
the difference between implant bone level at re-examination and baseline.
Tooth bone level was also registered at re-examination and baseline and was defined as the
distance between the cemento-enamel junction and the tooth bone crest. Tooth bone loss
was calculated as the difference between tooth bone level at re-examination and baseline.
Probing depth was registered at 6 sites per implant and contralateral tooth and gingival
index (Loë & Silness 1963) and plaque index (Sillness & Loë 1964) were scored at four sites
per implant.
Statistical analysis
Mean values and standard deviations were calculated for all continuous variables (soft tissue
levels, total PES, total WES, implant bone loss, tooth bone loss, implant probing depth,
contralateral tooth probing depth, implant gingival index, implant plaque index), whereas
frequency distributions were given for categorical variables (PES and WES criteria, recession
at the neighbouring tooth, infra-position of the implant crown). Alterations over time in soft
tissue levels and aesthetic parameters were evaluated using the Wilcoxon signed ranks test.
Comparison between cases with full documentation and cases lacking baseline clinical
photographs was performed by means of the Mann-Whitney-U test. Intra-assessor reliability
of soft tissue levels was evaluated using the intra-class correlation coefficient. Kappa
statistics were used to assess intra-assessor reliability of aesthetic ratings. The level of
significance was set at 0.05.
Results
8
One hundred and one patients who had been treated with a single implant between 1987
and 1993 at the Centre of Dental Specialist Care, were possible candidates for a clinical
inspection. Fifty-three of them agreed to attend such examination, however 3 patients did
not show up at the scheduled visit. Hence, 50 patients who received 62 single implants were
originally included. Three of these implants failed in the early healing phase, resulting in a
sample of 59 clinically-evaluable single implants. The clinical and radiographic outcome of
this patient group can be found in a recent paper (Dierens et al. 2012). Twenty-nine patients
did not meet the additional inclusion criteria for soft tissue evaluation. Nine of the 21
remaining patients were female and mean age was 23 years (SD 6, range 16-41) and 41 years
(SD 7, range 33-58) at implant placement and re-examination, respectively. Thus, the mean
follow-up was 18 years (SD 1, range 16-22). None of the patients had been suffering from
systemic disease or had been taking medication that could induce gingival overgrowth. One
patient was a smoker. All patients were periodontally-healthy at implant placement and
remained periodontally-healthy during follow-up as based on the definition described by
Page and Eke (2007). Nineteen patients had received 1 single implant, 1 patient had received
2 single implants and 1 patient had received 3 single implants. Thus, in total 24 single
implants had been installed of which 10 in a lateral incisor position, 8 in a central incisor
position, 4 in a premolar position and 2 in a canine position. In the 16 to 22 year period, only
one patient received a crown on a natural tooth neighbouring the implant restoration.
Neighbouring teeth were not additionally restored in any other patient and surgical
procedures were never performed adjacent to the implant restoration.
Soft tissue levels
The intra-class correlation coefficient on duplicate soft tissue measurements was 0.725 (p <
0.001) indicative of substantial intra-assessor reliability. Table 1 shows soft tissue levels at
baseline and at re-examination. Peri-implant levels remained stable over a 16 to 22 year
observation period (p ≥ 0.372). However, clinical tooth crown length showed a significant
increase of 0.5 mm on average (p = 0.039). About half of the cases (13/24, 54 %)
demonstrated midfacial recession after 16 to 22 years of function. Minor recession was
found in 8/24 (33 %) cases, whereas 5/24 (21 %) cases showed major midfacial recession.
The vast majority of the cases (17/24, 71 %) demonstrated infra-position of the implant
9
crown after 16 to 22 years of function. Minor infra-position was found in 7/24 (29 %) cases,
whereas 10/24 (42 %) cases showed major infra-position.
(HERE APPROXIMATELY TABLE 1 PLEASE)
Aesthetic parameters
The kappa value on duplicate registration of the PES criteria was ≥ 0.797 (p < 0.001)
indicative of substantial intra-assessor reliability. Table 2 shows the results of the PES and its
7 criteria sorted per time point. There was no significant difference in the PES or the 7
criteria between baseline and re-examination (p ≥ 0.132). Alveolar process deficiency and
papillae scored worst at both time points with an unfavourable outcome in 7/24 (29 %)
cases. Most satisfying at both time points was soft tissue contour. The mean PES at baseline
was 7.42 with aesthetic failure in 10/24 (42 %) of the cases and (almost) perfect outcome in
1 case (4 %). After 16 to 22 years of function the mean PES was 7.71 with aesthetic failure in
9/24 cases (38 %) and (almost) perfect outcome in 1 case (4 %).
The kappa value on duplicate registration of the WES criteria was ≥ 0.851 (p < 0.001)
indicative of almost perfect intra-assessor reliability. Table 2 shows the results of the WES
and its 5 criteria sorted per time point. There was no significant difference in the WES or the
5 criteria between baseline and re-examination (p ≥ 0.153). The mean WES at baseline was
5.43 with aesthetic failure in 11/24 (46 %) of the cases and (almost) perfect outcome in 3/24
(13 %) of the cases. After 16 to 22 years of function the mean WES was 5.33 with aesthetic
failure in 10/24 (42 %) of the cases and (almost) perfect outcome in 6/24 (25 %) of the cases.
Of the 59 clinically-evaluable single implants only 24 met the additional inclusion criteria for
longitudinal aesthetic evaluation. Eighteen of the remainder could also be aesthetically
evaluated, yet only after 16 to 22 years of function given the lack of baseline clinical
photographs on these cases. Table 2 shows the results on the PES and WES of these 18 single
implants. There was no significant difference for any of the parameters after 16 to 22 years
of function between the 24 cases with full documentation and the 18 cases lacking baseline
clinical photographs.
(HERE APPROXIMATELY TABLE 2 PLEASE)
10
Clinical and radiographic parameters
Table 3 shows the clinical and radiographic outcome of the 24 cases with full documentation
and the 18 cases lacking baseline clinical photographs. There was no significant difference in
any of the parameters between these patient groups. Implant and tooth bone loss were
limited in the long term with mean values below 1 mm (fig. 2).
(HERE APPROXIMATELY TABLE 3 PLEASE)
DiscussionTo the best of our knowledge this is the first longitudinal study with long term data on soft
tissue levels and aesthetics following single implant treatment.
In this study peri-implant soft tissue levels remained stable over a 16 to 22 year period,
which could be considered remarkable, especially since several studies have demonstrated
significant short-term alterations in soft tissue levels (Grunder 2000, Henriksson & Jemt
2004, Cardaropoli et al. 2006, Juodzbalys & Wang 2007, Lai et al. 2008, Chen et al. 2009,
Cosyn et al. 2011, Buser et al. 2011, den Hartog et al. 2011, Gallucci et al. 2011a, Raes et al.
2011). The latter may not necessarily contrast with our findings since baseline clinical
photographs pertained to the first year of function in our patient sample. This time frame
may not enable to detect early soft tissue changes, yet these may contribute most to soft
tissue dynamics. The latter may be illustrated by recently published one- and three-year data
on immediate implant treatment (De Rouck et al. 2008, Cosyn et al. 2011). De Rouck and co-
workers (2008) demonstrated significant papilla reduction and midfacial recession in the
early stages of healing following such treatment. Yet, after 3 years of function the same
patient group showed full papilla regeneration and some reduction in midfacial recession
(Cosyn et al. 2011). The present long term study failed to demonstrate significant midfacial
recession at the implant restoration, which could be a reflection of the fact that in the early
days turned implants were used in a strict palatal position. Such position could be confirmed
by clinical evaluation in the vast majority of the cases and ensures a thick buccal bone wall
supporting soft tissue stability.
In contrast to peri-implant soft tissue levels, gingival levels at adjacent natural teeth
demonstrated significant recession in the 16 to 22 year period. In fact, over one fifth of the
11
cases (21 %) showed major midfacial recession. These findings may suggest that peri-implant
soft tissues show more resistance to recession than gingival tissues. We believe that
quantitative rather than qualitative disparities may explain this phenomenon. At least in the
short term, soft tissues are thicker at the buccal aspect of implants than teeth (Henriksson &
Jemt 2004, Cardaropoli et al. 2006), which may be explained by a palatal implant position in
relation to the neighbouring teeth on one hand, and a buccal repositioning of the peri-
implant mucosa at second stage surgery on the other hand. Moreover, the abutment
diameters used in the developmental phase of single implant restorations in the late
eighties, can be considered smaller than the root diameters of the replaced or neighbouring
teeth, possible leaving more space for surrounding tissues. The risk for soft tissue recession
mainly relates to its thickness, as shown around teeth (Melsen and Allais 2005, Yared et al.
2006) and implants (Kan et al. 2011).
A particularly interesting finding was that the vast majority of the cases (71 %) demonstrated
infra-position of the implant crown after 16 to 22 years of function. In nearly half of them
(42 %) a major distortion was found indicating substantial eruption of the neighbouring
teeth. Interestingly, Bernard and co-workers (2004) demonstrated infra-position of the
implant crown in all treated cases after on average 4.2 years of function irrespective of age,
gender and implant position. Recently, Chang and Wennström (2012) showed an increase in
the vertical position of neighbouring teeth in relation to the implant in 58 % of the cases
after 8 years of function. With an observation period of more than 15 years Jemt et al.
(2007) showed infra-occlusion of the implant crown in 60 % of the cases. Our observations
seem to be in line with these investigations and point to an important aspect of treatment
outcome with possible aesthetic consequences.
Another primary goal of this study was to objectively assess the aesthetic outcome of single
implant treatment and to evaluate possible time effects. Hitherto, a number of studies have
been published on the aesthetic outcome of single implant restorations using the PES and/or
WES (Juodzbalys & Wang 2007, Lai et al. 2008, Belser et al. 2009, Chen et al. 2009, Cosyn et
al. 2010, 2011, 2012a, Buser et al. 2011, den Hartog et al. 2011, Gallucci et al. 2011b, Raes et
al. 2011). When compared to these studies it is clear that the aesthetic outcome of single
implant treatment was poor in the late eighties and early nineties given a mean PES of 7.42
and a mean WES of 5.43 at baseline. Given that, it should not be surprising that only very
few cases demonstrated (almost) perfect aesthetic outcome based on arbitrarily chosen
12
thresholds by Cosyn et al. (2010). When interpreting these results, one should take into
account that at the time implant therapy was in a developmental stage in terms of implant
surface topography and prosthetic components, mainly focusing on functional rehabilitation.
In contemporary practice more attention is paid to an optimal three-dimensional implant
position and the use of biomaterials, provisional restorations and connective tissue grafts
have become common. It seems that these aspects have substantially improved the
aesthetic outcome of single implant treatment over the years (Juodzbalys & Wang 2007, Lai
et al. 2008, Belser et al. 2009, Chen et al. 2009, Cosyn et al. 2010, 2011, 2012a, Buser et al.
2011, den Hartog et al. 2011, Gallucci et al. 2011b, Raes et al. 2011), yet they also drastically
increased its complexity. In addition, these treatment concepts still need to withstand the
test of time given the relatively short time frame in which they were studied. On the other
hand, the present study did not show significant differences in the PES or WES between
baseline and re-examination, indicating stable aesthetics over a 16 to 22 year period for
conventional single implant treatment.
For a number of reasons aforementioned results should be interpreted with caution,
especially in terms of generalizability. First, important information may not be available in a
retrospective study. Intra-surgical data on the thickness of the buccal bone wall upon
implant installation would have been valuable since the buccal bone wall possibly affects
midfacial recession. Cone beam CT could be used to overcome this, yet technology was not
yet available in the late eighties and is still lacking accuracy (Raes et al. 2011). Other relevant
parameters that could not be thoroughly assessed given the retrospective study design
include restoration materials, prosthetic design and oral hygiene. Apart from the study
design, a second limitation relates to the small study sample. One could question whether
the sample size was sufficient to demonstrate significant peri-implant soft tissue alterations.
Post factum calculations based on a change of 0.4 mm (e.g. mesial papilla), SD of 1.7, an
alpha error of 0.05 and statistical power of 0.80 resulted in a required sample size of 12.
Thus, the present case series including 24 single implants was not underpowered to show a
significant time effect. On the other hand, 186 single implants would be needed in order to
demonstrate a 0.1 mm significant change (e.g. clinical implant crown length). Theoretically,
our sample was underpowered to show this time effect, yet one could question the clinical
relevance of a 0.1 mm difference. A third limitation refers to the methodology. Albeit clinical
photographs were superimposed based on the best fit of the implant crown, they were
13
possibly taken from different angles. This could have an impact on accuracy. On the other
hand, registration of soft tissue data demonstrated high precision given substantial intra-
assessor reliability on duplicate measurements. A final concern could relate to selection bias
as it is conceivable that only baseline clinical photographs had been taken from the best
cases. We consider this unlikely and the reason for that may be threefold. First, baseline PES
and WES were 7.42 and 5.43, respectively. These data reflect a rather poor outcome instead
of a favourable outcome. Second, final PES and WES were also calculated for 18 cases
without baseline clinical photographs and these were not significantly different from the 24
cases with full documentation, at least not after 16 to 22 years of function. Third, clinical and
radiographic parameters on the same 18 cases without baseline clinical photographs were
also not significantly different from the 24 cases with full documentation.
In conclusion, this retrospective case series demonstrated stable peri-implant soft tissue
levels over a 16 to 22 year period following single implant treatment in periodontally-healthy
patients. On the other hand, neighbouring teeth showed significant midfacial recession and
eruption. Based on objective parameters baseline aesthetics was considered poor, yet a
significant time effect could not be demonstrated, indicating long term stability.
AcknowledgementsThe authors express their gratitude to Ulf Lindén who initiated this study, to Rigmor Persson
for analysing all radiographs and to all co-workers at the Centre of Dental Specialist Care in
Malmö for supporting the clinical part of this project.
References
Adell, R., Lekholm, U., Rockler, B., Brånemark, P.I. (1981) A 15-year study of osseointegrated implants in the treatment of the edentulous jaw. International Journal of Oral Surgery 10, 387-416.
Belser, U.C., Grütter, L., Vailati, F., Bornstein, M.M., Weber, H.P., Buser, D. (2009) Outcome evaluation of early placed maxillary anterior single-tooth implants using objective esthetic criteria: a cross-sectional, retrospective study in 45 patients with a 2- to 4-year follow-up using pink and white esthetic scores. Journal of Periodontology 80, 140-151.
14
Bergenblock, S., Andersson, B., Fürst, B., Jemt, T. (2010) Long-term follow-up of CeraOne single-implant restorations: an 18-year follow-up study based on a prospective patient cohort. Clinical Implant Dentistry and Related Research, Epub ahead of print.
Berglundh, T., Persson, T., Klinge, B. A. (2002) A systematic review of the incidence of biological and technical complications in implant dentistry reported in prospective longitudinal studies of at least 5 years. Journal of Clinical Periodontology 29, 197-212.
Bernard, J.P., Schatz, J.P., Christou, P., Belser, U., Kiliaridis, S. (2004) Long-term vertical changes of the anterior maxillary teeth adjacent to single implants in young and mature adults. A retrospective study. Journal of Clinical Periodontology 31, 1024-1028.
Brånemark, P.I., Hansson, B.O., Adell, R., Breine, U., Lindström, J., Hallén, O., Ohman, A. (1977) Osseointegrated implants in the treatment of the edentulous jaw. Experience from a 10-year period. Scandinavian Journal of Plastic and Reconstructive Surgery 16, 1-132.
Buser, D., Wittneben, J., Bornstein, M.M., Grütter, L., Chappuis, V., Belser, U.C. (2011) Stability of contour augmentation and esthetic outcomes of implant-supported single crowns in the esthetic zone: 3-year results of a prospective study with early implant placement postextraction. Journal of Periodontology 82, 342-349.
Cardaropoli, G., Lekholm, U., Wennström, J.L. (2006) Tissue alterations at implant-supported single-tooth replacements: a 1-year prospective clinical study. Clinical Oral Implants Research 17, 165-171.
Chang, M., Wennström, J.L. (2012) Longitudinal changes in tooth/single-implant relationship and bone topography: an 8-year retrospective analysis. Clinical Implant Dentistry and Related Research 14, 388-394.
Chen, S.T., Darby, I.B., Reynolds, E.C., Clement, J.G. (2009) Immediate implant placement postextraction without flap elevation. Journal of Periodontology 80, 163-172.
Cosyn, J., De Bruyn, H., Cleymaet , R. (2012a) Soft tissue preservation and pink aesthetics around single immediate implant restorations: a 1-year prospective study. Clinical Implant Dentistry and Related Research, Epub ahead of print.
Cosyn, J., Eghbali, A., De Bruyn, H., Collys, K., Cleymaet, R., De Rouck, T. (2011) Immediate single-tooth implants in the anterior maxilla: 3-year results of a case series on hard and soft tissue response and aesthetics. Journal of Clinical Periodontology 38, 746-753.
Cosyn, J., Eghbali, A., De Bruyn, H., Dierens, M., De Rouck, T. (2010) Single implant treatment in healing versus healed sites of the anterior maxilla: an aesthetic evaluation. Clinical Implant Dentistry and Related Research, Epub ahead of print.
Cosyn, J., Raes, S., De Meyer, S., Raes, F., Buyl, R., Coomans, D., De Bruyn, H. (2012b) An analysis of the decision-making process for single implant treatment in general practice. Journal of Clinical Periodontology 39, 166-172.
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Creugers, N.H., Kreulen, C.M., Snoek, P.A., de Kanter, R.J. (2000) A systematic review of single-tooth restorations supported by implants. Journal of Dentistry 28, 209-217.
De Rouck, T., Collys, K., Cosyn, J. (2008) Immediate single-tooth implants in the anterior maxilla: a 1-year case cohort study on hard and soft tissue response. Journal of Clinical Periodontology 35, 649-657.
den Hartog , L., Slater, J.J., Vissink, A., Meijer, H.J., Raghoebar, G.M. (2008) Treatment outcome of immediate, early and conventional single-tooth implants in the aesthetic zone: a systematic review to survival, bone level, soft-tissue, aesthetics and patient satisfaction. Journal of Clinical Periodontology 35, 1073-1086.
den Hartog, L., Raghoebar, G.M., Slater, J.J., Stellingsma, K., Vissink, A., Meijer, H.J. (2011) Single-tooth implants with different neck designs: a randomized clinical trial evaluating the aesthetic outcome. Clinical Implant Dentistry and Related Research, Epub ahead of print.
Dierens, M., Vandeweghe, S., Kisch, J., Nilner, K., De Bruyn, H. (2012) Long-term follow-up of turned single implants placed in periodontally healthy patients after 16-22 years: radiographic and peri-implant outcome. Clinical Oral Implants Research 23, 197-204.
Fürhauser, R., Florescu, D., Benesch, T., Haas, R., Mailath, G., Watzek, G. (2005) Evaluation of soft tissue around single-tooth implant crowns: the pink esthetic score. Clinical Oral Implants Research 16, 639-644.
Gallucci, G.O., Grütter, L., Chuang, S.K., Belser, U.C. (2011a) Dimensional changes of peri-implant soft tissue over 2 years with single-implant crowns in the anterior maxilla. Journal of Clinical Periodontology 38, 293-299.
Gallucci, G.O., Grütter, L., Nedir, R., Bischof, M., Belser, U.C. (2011b) Esthetic outcomes with porcelain-fused-to-ceramic and all-ceramic single-implant crowns: a randomized clinical trial. Clinical Oral Implants Research 22, 62-69.
Grunder, U. (2000) Stability of the mucosal topography around single-tooth implants and adjacent teeth: 1-year results. International Journal of Periodontics & Restorative Dentistry 20, 11-17.
Henriksson, K., Jemt, T. (2004) Measurements of soft tissue volume in association with single-implant restorations: a 1-year comparative study after abutment connection surgery. Clinical Implant Dentistry and Related Research 6, 181-189.
Jemt, T., Ahlberg, G., Henriksson, K., Bondevik, O. (2007) Tooth movements adjacent to single-implant restorations after more than 15 years of follow-up. International Journal of Prosthodontics 20, 626-632.
Jemt, T. (1986) Modified single and short-span restorations supported by osseointegrated fixtures in the partially edentulous jaw. Journal of Prosthetic Dentistry 55, 243–247.
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Jemt, T. (2008) Single implants in the anterior maxilla after 15 years of follow-up: comparison with central implants in the edentulous maxilla. International Journal of Prosthodontics 21, 400-408.
Jung, R.E., Pjetursson, B.E., Glauser, R., Zembic, A., Zwahlen, M., Lang, N.P. (2008) A systematic review of the 5-year survival and complication rates of implant-supported single crowns. Clinical Oral Implants Research 19, 119-130.
Juodzbalys, G., Wang, H.L. (2007) Soft and hard tissue assessment of immediate implant placement: a case series. Clinical Oral Implants Research 18, 237-243.
Kan, J.Y., Rungcharassaeng, K., Lozada, J.L., Zimmerman, G. (2011) Facial gingival tissue stability following immediate placement and provisionalization of maxillary anterior single implants: a 2- to 8-year follow-up. International Journal of Oral and Maxillofacial Implants 26, 179-187.
Lai, H.C., Zhang, Z.Y., Wang, F., Zhuang, L.F., Liu, X., Pu, Y.P. (2008) Evaluation of soft-tissue alteration around implant-supported single-tooth restoration in the anterior maxilla: the pink esthetic score. Clinical Oral Implants Research 19, 560-564.
Loë, H., Silness, J. (1963) Periodontal disease in pregnancy. I. Prevalence and severity. Acta Odontologica Scandinavica 21, 533-551.
Meijer, H.J., Stellingsma, K., Meijndert, L., Raghoebar, G.M. (2005) A new index for rating aesthetics of implant-supported single crowns and adjacent soft tissues--the Implant Crown Aesthetic Index. Clinical Oral Implants Research 16, 645-649.
Meijndert, L., Meijer, H.J., Stellingsma, K., Stegenga, B., Raghoebar, G.M. (2007) Evaluation of aesthetics of implant-supported single-tooth replacements using different bone augmentation procedures: a prospective randomized clinical study. Clinical Oral Implants Research 18, 715-719.
Melsen, B., Allais, D. (2005) Factors of importance for the development of dehiscences during labial movement of mandibular incisors: a retrospective study of adult orthodontic patients. American Journal of Orthodontics and Dentofacial Orthopedics 127, 552-561.
Page, R.C., Eke, P.I. (2007) Case definitions for use in population-based surveillance of periodontitis. Journal of Periodontology 78, 1387-1399.
Raes, F., Cosyn, J., Crommelinck, E., Coessens, P., De Bruyn, H. (2011) Immediate and conventional single implant treatment in the anterior maxilla: 1-year results of a case series on hard and soft tissue response and aesthetics. Journal of Clinical Periodontology 38, 385-394.
Raes, F., Renckens, L., Aps, J., Cosyn, J., De Bruyn, H. (2011) Reliability of circumferential bone level assessment around single implants in healed ridges and extraction sockets using Cone Beam CT. Clinical Implant Dentistry and Related Research, Epub ahead of print.
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Silness, J., Loë, H. (1964) Periodontal disease in pregnancy. II. Correlation between oral hygiene and periodontal conditions. Acta Odontologica Scandinavica 22, 121-135.
Yared, K.F., Zenobio, E.G., Pacheco, W. (2006) Periodontal status of mandibular central incisors after orthodontic proclination in adults. American Journal of Orthodontics and Dentofacial Orthopedics 130, 1-8.
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