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Eur J Oral Implantol 2009;2(3)209217
CLINICAL ARTICLE
Purpose: To evaluate aesthetic and patient satisfaction after tooth extraction using a bone substitute
(and soft tissue grafting when tissue thickness was lacking) under a pontic to preserve the alveolar
ridge for aesthetic purposes. The contralateral natural tooth acted as internal control.
Materials and methods: All patients with at least one site under a pontic augmented with Bio-Oss or
Bio-Oss Collagen with or without a concomitant connective tissue graft with at least a follow-up of 6
months after the ridge preservation procedure were eligible for the present retrospective study. Sites with
a damaged buccal wall were excluded. Outcome measures were: aesthetics (pink esthetic score, PES)
evaluated by an independent and blinded dental hygienist on the basis of clinical pictures, patient sat-
isfaction, patient preference and complications.
Results: Twenty-six patients were consecutively treated, and 23 patients attended the evaluation visit.
In seven patients, soft tissue grafts were performed in conjunction with Bio-Oss placement. Eight to
86 months after the ridge augmentation procedure (mean 38 months), there were no statistically sig-
nificant differences observed in PES between preserved sites and control teeth. Patient satisfaction did
not show any statistically significant difference between the two groups either. All patients declared
they would undergo the same procedure again.
Conclusions: Bio-Oss placement in post-extractive sites with a remaining buccal bone plate lead to a
good aesthetic result. Randomised clinical trials with suitable control groups are needed to identify the
most effective techniques and/or materials to preserve ridges under pontics.
Markus Schlee, Marco Esposito
Aesthetic and patient preference usinga bone substitute to preserve extraction sockets
under pontics. A cross-sectional survey
aesthetic, bone substitutes, observational study, pontic ridge preservationKey words
Markus Schlee, DSpecialist in Periodonto
Private practice, Forchh
Germany
Marco Esposito, DPhD
Senior Lecturer, Oral anMaxillofacial Surgery, S
of Dentistry, The Unive
of Manchester, UK and
Associated Professor,
Department of Biomat
The Sahlgrenska Acade
at Gteborg University
Sweden.
Correspondence to:
Dr Marco Esposito
School of Dentistry, Or
and Maxillofacial Surge
The University of
Manchester, Higher
Cambridge Street,
Manchester, M15 6FH
E-mail:
espositomarco@hotma
Introduction
After tooth extraction, the alveolar bone remodels and
resorbs1-4. Two-thirds of this reduction occurs within
the first 3 months and within 1 year the clinical width
of the alveolar ridge is reduced by approximately
50%1-4. The mean vertical loss of tissues at single
extracted sites ranges between 1 to 4 mm1-4, depend-
ing on site location. This physiological phenomenon
occurs at different rates and degrees among various
individuals and in some cases it can be very pro-
nounced1-4. In sockets previously damaged by trauma
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or chronic inflammatory processes, bone resorption
may be more pronounced. Localised alveolar bone
resorption does not affect the possibility of placing a
conventional bridge for replacing the lost dentition,
but may affect aesthetics and the possibility of placing
dental implants. Particularly in aesthetic areas and in
those patients exposing visible portions of gum when
speaking and smiling, the resorbed alveolar crest could
be a cause of social discomfort and embarrassment.
Various techniques are currently used for ridge
preservation or reconstruction, ranging from softtissue grafts to augmentation with bone grafts and/or
bone substitutes1,3-15. Despite numerous publications
on this topic, the number of reliable randomised con-
trolled trials is rather limited1,4,13.
The aim of this cross-sectional survey was to evalu-
ate aesthetic and patient satisfaction after tooth extrac-
tion using a bone substitute (and soft tissue grafting
when tissue thickness was lacking) under a pontic to
preserve the alveolor ridge for aesthetic purposes. The
contralateral natural tooth served as internal control.
This study is reported following the STROBE Statement
(http://www.strobe-statement.org/) for observational
studies.
Materials and methods
This investigation was designed as a cross-sectional
survey including consecutively treated patients who,
at recall, were informed about the study procedure
and signed a written informed consent form. Allpatients who underwent a procedure of ridge preser-
vation after tooth extraction with Bio-Oss (Geistlich
Pharma AG, Wolhusen, Switzerland) with or without
soft tissue grafting between 1 January 2001 and
30 September 2008 at a German private dental prac-
tice by a single operator (Markus Schlee) and having
a follow-up of at least 6 months after the ridge preser-
vation were considered to be eligible for this study. In
cases of several augmented sockets in the same
patient, only one site was randomly selected for each
Eur J Oral Implantol 2009;2(3)209217
210 Schlee/Esposito Aesthetic and patient preference using a bone substitute
Table 1 Decision tree for soft tissue grafting.
Socket
Thick biotype Thin biotype
No recession Recession No recession Recession
Socket sealwith pontic
Socket seal with connective tissue graft
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patient by drawing a lot. The selected socket had tobe under a pontic element. The corresponding con-
tralateral natural tooth acted as a control (e.g. if the
socket of tooth 14 was preserved, its control was the
tooth in position 24). If the contralateral tooth was
missing, the contralateral tooth most similar to the test
site was chosen. In the case where the only aug-
mented site was a central incisor, the contralateral lat-
eral incisor was chosen as control to avoid evaluation
of two adjacent teeth.
To be treated for ridge preservation, the patients
had to be 18 years or older and require the removal or
one or more teeth that were going to be rehabilitated
with a fixed partial denture. Exclusion criteria were:
pregnancy, denture systemic diseases, smoking of
more than 10 cigarettes per day, sites with acute infec-
tion or not in aesthetic areas or not under pontic ele-
ments, and lack of patient interest in the preservation
procedure.
The clinical procedures were the following: after
local anaesthesia with Ultracain D-S forte (articaine
hydrochloride, adrenaline hydrochloride, 1:100,000,Hoechst, Frankfurt, Germany), the periodontal fibres of
the tooth to be extracted were dissected with a sharp
blade (PFISCHLEE, Hu-Friedy, Chicago, USA) as far
subcrestally as possible. Great care was taken to pre-
serve the buccal bone. After being mobilised, the teeth
were extracted as gently as possible with appropriate
forceps. Granulation tissue and sulcular epithelium
were carefully removed with sharp spoons and a blade
(Lucas CL84, Hu-Friedy). After being moistened with
blood, Bio-Oss or Bio-Oss Collagen was used as bone
filler. Bio-Oss is composed of particles of deproteinisedbovine-derived bone mineral to which collagen can be
added (Bio-Oss Collagen). The material was discreetly
condensed to the crestal edge of the bone. The choice
between Bio-Oss or Bio-Oss Collagen was based on
the clinicians preference for clinical handling.
Connective tissue grafts (CTG) were performed in
the presence of thin gingival biotypes or gingival
asymmetries like recessions (Table 1 and Fig 1). An
undermining tunnelling technique starting in the
sulcus was used. The split flap exceeded the mucogin-
gival junction apically to get a sufficient mobilisation
of the flap. A CTG harvested from the palate was
inserted under the periosteum to thicken the tissue on
the buccal aspect, to close the extraction site and to
balance soft tissue dehiscence in the sulcular area
(Fig 2). 6-0 Premilene (Braun, Melsungen, Germany)
sutures were used to close the wounds. Only a slight
contact between the CTG and the provisional restora-
tion was allowed to avoid necrosis in case of swelling.
Sutures were removed after 7 days. After 6 weeks the
temporary prosthesis was removed and a cavity wasprepared in the gingiva according the shape of a mod-
ified ovate pontic (mOP). The temporary prosthesis
was adapted to the cavity with light-curing compos-
ites and then carefully polished. The profile of the
mOP differs from a regular ovate pontic16-18. The sur-
faces bucally and proximally are flat, and the edges are
just a little bit rounded. The lingual aspect is shaped
conventionally. This supports the tissue and may result
in a better and more natural shape of the pseudo-
sulcus and the papillae (Fig 3).
Eur J Oral Implantol 2009;2(3)209217
Schlee/Esposito Aesthetic and patient preference using a bone substitute
Fig 1 Thin biotype and gingival asymmetry prior to extrac-tions.
Fig 2 After extraction of the maxillary incisors, two implantswere placed in the sockets of the lateral incisors, a connec-tive tissue graft was slipped underneath a tunnelling splitflap and extraction sockets of the central incisors were filledwith Bio-Oss Collagen.
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In presence of thick biotypes and harmonious gin-
gival levels, no soft tissue graft was implemented and
the Bio-Oss was kept in place with the mOP (Figs 4
to 8). A certain migration of Bio-Oss granules occurred
(Fig 9). Temporary prostheses were removed every 4
weeks to eliminate the embedded Bio-Oss granules
until any migration came to an end (Fig 10).
After a healing period of 6 months (Figs 11 and
12) impressions for the final restorations were
taken. Major efforts were taken to preserve the
Eur J Oral Implantol 2009;2(3)209217
212 Schlee/Esposito Aesthetic and patient preference using a bone substitute
Fig 3 The gingiva was shaped with a modified ovate pon-tic.
Fig 4 Clinical situation before extraction.
Fig 5 X-rays before extraction demonstrate the residualbone level.
Fig 6 The extraction sockets were filled with Bio-OssCollagen.
Fig 7 The socket was filled to the crestal edge to minimiseparticle migration into the soft t issues.
Fig 8 Grafts were kept in place by modified ovate pontics.
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gained soft tissue contour for the impression. To
reproduce the gained soft tissue profile, the frame
was lined with polyether (Impregum, 3M ESPE,
Neuss, Germany) and the stone casts were adapted
by the dental technician. Final restorations were
accurately polished before and after glazing to
obtain a smooth and homogenous surface in con-
tact with the soft tissues.
Patients were identified electronically by browsing
the patient database with a search tool by a dental
assistant (Ulrike Huemmer) using the keywordssocket preservation. It was decided to include in the
present study only patients having preserved buccal
bone at the extraction sites, therefore 11 patients not
fulfilling this requirement were not included in the
study or evaluated. All eligible patients were recalled
to attend the dental practice for the evaluation. It was
annotated if a patient could not be contacted or
refused to attend the follow-up assessment. In that
case, the reason of the refusal was noted. Outcome
measures were the following.
Aesthetics were evaluated using the pink esthetic
score (PES)19. At the recall visit, two clinical pic-
tures (one vestibular and one occlusal digital pho-
tograph) were taken, including both adjacent
teeth of both the test and control sites under the
same light conditions and using similar framing
(Fig 13). Once all pictures were collected, an
independent and blinded trained dental hygien-
ist (Tatjana Huck) scored the pictures visualised
on a computer screen for aesthetics. In brief,
seven variables were evaluated: mesial papilla,distal papilla, soft tissue level, soft tissue contour,
alveolar process deficiencies, soft tissue colour
and texture. A 0-1-2 scoring system was used, 0
being the lowest and 2 being the highest value,
with a maximum achievable score of 1419.
Patient satisfaction: at the recall appointment, an
independent outcome assessor (Ulrike Huem-
mer) provided a mirror to the patients to show
both test and control teeth on which patients had
to express their opinions and were asked are you
Eur J Oral Implantol 2009;2(3)209217
Schlee/Esposito Aesthetic and patient preference using a bone substitute
Fig 9 Some Bio-Oss particles migrated trough the gingivaand were removed after 8 weeks.
Fig 10 No inflammation was visible after 12 weeks.
Fig 11 The provisional restoration shaped and maintainedboth papillae and sulci.
Fig 12 Volume of the ridge was maintained after 6 months.
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satisfied with the aesthetic outcome of the gum
surrounding this tooth? Then, indicating only
the preserved site, the outcome assessor asked
Would you undergo the same procedure again?
Possible answers were: i) definitively yes, ii) yes,
iii) uncertain, iv) no and v) absolutely not. The
questions were always posed with exactly the
same wording.
Patient preference: patients were asked which of
the two sites they preferred, focussing their
attention to their gums. Possible answers were:i) the augmented site, ii) the natural site, iii) both
are equally nice and iv) both are equally bad.
Data analysis was carried out according to a pre-
established analysis plan. A biostatistician with
expertise in dentistry analysed the data, without
knowing the group codes. Differences in PES and
patient satisfaction (ordinal data) were compared
between groups using the Wilcoxon signed-rank test.
Patient preference was calculated with odds ratios
(OR) between patients preferring the preserved site
and those preferring the natural control site using the
McNemar test. All statistical comparisons were
conducted at the 0.05 level of significance.
Results
A total of 26 patients with preserved buccal bony wall
were consecutively treated. Three patients (12%) did
not want to attend the recall visit (dropouts). Of theattending patients, 20 (87%) were females and three
(13%) males. Age at the time of the preservation pro-
cedure ranged from 29 to 69 years (mean 53 years).
Eighteen patients (78%) declared themselves to be
non-smokers and five (22%) to be smokers. In 16
(70%) patients the socket was filled with Bio-Oss only,
whereas in seven (30%) patients the sites were also
augmented with a soft tissue graft. Follow-up ranged
from 8 to 86 months after the preservation procedure
(mean 38 months). The location of the preserved sites
Eur J Oral Implantol 2009;2(3)209217
214 Schlee/Esposito Aesthetic and patient preference using a bone substitute
Fig 13 13 Examples of clinical pictures scored for aesthetics using the pink esthetic score (PES): a) frontal picture of a pre-served post-extractive site (canine) under a pontic, b) occlusal picture, c) anterior picture of the contralateral canine that act-ed as intra-individual control and d) occlusal picture.
a
c
b
d
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and their control contralateral natural dentition is illus-
trated in Table 2.
Frequencies for PES assessed at preserved and con-
trol sites by an independent and blinded hygienist are
illustrated in Table 3. There were no statistically signif-
icant differences in PES between preserved and con-trol sites (Wilcoxon signed-ranks test P = 0.248).
The degree of patient satisfaction with respect to
the aesthetic outcome at both preserved and control
sites can be seen in Table 4. There were no statistically
significant differences with respect to aesthetics
according to patient opinion between preserved and
the control sites (Wilcoxon signed-rank test
P = 0.527). All patients declared that they would do
the ridge preservation again. Fifteen patients (65%)
replied with a definitively yes and eight patients
(35%) with a yes.Patient preferences between preserved and con-
trol sites are summarised in Table 5. There was no sta-
tistically significant difference with respect to patient
preference (OR 0.43, 95% CI 0.07 to 1.88; McNe-
mar test P = 0.34), with trends favouring preserved
sites.
Discussion
The main finding of the present study was that,
between 8 and 86 months after the ridge preservation
procedure (mean 38 months), no statistically signifi-
cant differences could be found in PES and patient sat-
isfaction when comparing post-extraction sites with
intact buccal bone filled with granular Bio-Oss under
pontics with their natural contralateral dentition. This
is a positive result indicating that this type of ridge
preservation procedure can lead to a good aesthetics
as evaluated by both an independent and blinded out-
come assessor and the patients themselves. This is inagreement with other studies showing that various
preservation techniques can reduce ridge resorp-
tion1,3,4,9, even though some preservation techniques
are associated with a substantial number of failures
and complications3 20,21 or they appear to be ineffec-
tive7.
No membranes were used in the present study,
since they were not shown to have any advantages
when used over a bone substitute in the case of socket
preservation8.
Eur J Oral Implantol 2009;2(3)209217
Schlee/Esposito Aesthetic and patient preference using a bone substitute
Site position(tooth position)
Number ofpreserved sites(%)
Number ofcontrol sites(naturaldentition) (%)
11 5 (22) 4 (17)
12 2 (9) 3 (13)
13 2 (9) 4 (17)
14 0 (0) 1 (4)
15 1 (4) 0 (0)
21 5 (22) 2 (9)
22 3 (13) 5 (22)
23 4 (17) 2 (9)
25 0 (0) 1 (4)
35 1 (4) 0 (0)
45 0 (0) 1 (4)
Table 2 Location opreserved sites andtheir control contraeral natural dentitio
Pink estheticscore
Number ofpreserved sites(%)
Number ofcontrol sites(naturaldentition) (%)
9 0 (0) 1 (4)
10 0 (0) 1 (4)
11 2 (9) 2 (9)
12 8 (38) 6 (26)
13 6 (26) 8 (35)
14 7 (30) 5 (22)
Table 3 Frequencifor the pink esthetscore at preservedcontrol sites. No sttically significant dferences were foun
Degree ofaestheticsatisfaction
Number ofpreserved sites(%)
Number ofcontrol sites(naturaldentition) (%)
Definitively satisfied 12 (52) 15 (65)
Satisfied 11 (48) 7 (30)
Uncertain 0 (0) 1 (4)
Table 4 Frequencifor aesthetic satisftion expressed by patient at preserveand control sites. Npatient expressed negative evaluatio
No statistically signcant differences wfound.
Patient preference Number of patients (%)
Preserved site 7 (30)
Control site 3 (13)
No preference (both nice) 13 (57)
Table 5 Frequenciefor patient preferenbetween preservedcontrol sites. No patient was dissatisfiewith both sites. Notistically significantferences.
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The major limitations of the present investigation
were the small sample size, the retrospective design
and the relatively high drop-out rates. Ideally, prospec-
tive studies with larger sample sizes should be con-
ducted. Retrospective studies are not the ideal study
design to evaluate efficacy of interventions22
, never-theless they can still provide some valuable informa-
tion. Randomised controlled clinical trials (RCTs) are
the gold standard to evaluate the efficacy of medical
interventions. So far a few RCTs have been published
evaluating various ridge preservation techniques1,4
showing that they are effective in minimising ridge
resorption.
A drop-out rate of 12% is acceptable. Several calls
were made to invite all patients to attend the evalua-
tion visit, but three patients expressed no intention to
attend. This is an observational study that included acohort of patients selected retrospectively. Patients
were not informed initially that they would be
assessed, as it happens in prospective studies, there-
fore patients that could have refused participation in
the study, were counted anyway and this could explain
why three patients refused to attend the evaluation
visit. Another possibility is that they were unsatisfied
with the outcome of the ridge preservation and
decided not to attend. Unfortunately, the patients did
not provide sufficient information to make an
informed opinion, so the reasons why they refused to
attend remain purely conjectural.
To date, this is the only study in which preserved
post-extractive sites under pontics were compared
with their contralateral natural teeth using aesthetic
assessments. This choice was dictated at protocol for-
mulation when it had to be decided which would have
been the control sites, as contralateral dentition was
the only available option.
The results of the present study can be extrapo-
lated to comparable patient populations if similar inter-ventions are provided by experienced professionals.
However, it should be emphasised once more that in
the present study only post-extractive sockets having
preserved buccal bone were included. Consequently,
these results may not apply to damaged extraction
sockets.
Conclusions
Placement of Bio-Oss in well-preserved post-extrac-
tion sites, sometimes in conjunction with soft tissue
augmentation, was associated with good aesthetics as
judged by an independent blinded hygienist andpatients themselves when compared with contralat-
eral sites with natural dentition. Randomised clinical
trials with suitable control groups are needed to iden-
tify the most effective techniques and/or materials to
preserve post-extractive sites under pontics.
Acknowledgements
The authors wish to thank Tatjana Huck (dental
hygienist) for serving as blinded outcome assessor forthe aesthetic outcome, and Ulrike Huemmer (dental
assistant) for identifying the patients and recording
their satisfaction and preference. This study was not
sponsored in the sense that free material was given,
however it was initiated on the request of Geistlich
Pharma AG.
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