3. Surgical Method
Background Information
Prof. Daniel Buser and Prof. Urs Belser:
The objective of implant therapy is a successful treatment result from an aesthetic and functional
point of view, with a high degree of predictability and low risk of aesthetic complications. The clinician
has four treatment options available (Haemmerle et al. 2004, Chen and Buser 2008), including early
implantation after 4 – 8 weeks of soft-tissue healing. While defining the therapy, an aesthetic risk
analysis is essential to determine the patient’s individual risk profile (Martin et al. 2006). This
comprises a total of 12 parameters, including 9 anatomical parameters. The present case history of a
25-year-old female patient indicates an overall moderate risk profile (see "Risk Profile" table).
In our view, immediate implantation on the day of extraction should only be selected under ideal
clinical conditions, which is only very rarely the case in the anterior maxillary region. In addition, due
to the complex degree of difficulty inherent in immediate implantation, only very experienced implant
specialists should use this method (Dawson and Chen, 2009). In patients with high risk factors, the
risk of aesthetic complications is considerably increased, whereby the recession of the facial mucosa
is the most important consideration. Consequently, frequent occurrence of soft-tissue recession
associated with immediate implant placement has been documented in a number of clinical studies
(Chen et al. 2005; Lindeboom et al. 2006; Kan et al. 2007; Evans and Chen 2008).
Early implantation 4 – 8 weeks following extraction is a good alternative to immediate implantation
because it shortens the treatment time and, at the same time, substantially reduces the risk of an
undesirable aesthetic complication (Buser et al. 2008a; Buser et al. 2009 , Buser et al. 2011). Our
understanding of the changes in the alveolar ridge following an extraction has improved considerably
over the previous 5 years. Various animal studies have shown that after the extraction, the bundle
bone, which coats the alveolus, is resorbed within 4 – 8 weeks as the blood supply from the periodontal
membrane to the bundle bone is disrupted by the extraction (Araujo et al. 2005). This bone resorption
is a biological phenomenon and cannot be prevented by the immediate placement of an implant
(Araujo et al. 2006). The thin facial bony ridge in the anterior mandible consists mostly of bundle
bone, for which reason generally a crater-shaped bony defect develops in the centre of the alveolus
due to the bone resorption following an extraction. For a good aesthetic result, local bone
augmentation in the sense of a bone contour augmentation is essential. The facial bony wall is
deliberately over-augmented with the aid of the GBR technique to create good pre-conditions for a
stable, aesthetic, long-term result.
From a surgical point of view, extraction preserving the tissues and without creating a flap is important
in order to prevent the additional bony resorption at the surface of the alveolar ridge which would be
caused by the removal of the periosteum (Wood et al. 197 2; Fickl et al. 2008). After curettage of the
alveolus, a collagen cone is generally applied, in order to stabilise the blood coagulum. Depending on
the size of the alveolus, a healing phase of 4 – 8 weeks is required. Thereby, an intact covering of soft
tissue is obtained, together with 3 – 6 mm of additional keratinised mucosa. Both of these are greatly
advantageous for the subsequent implantation, in order to achieve a tension-free primary wound
closure without massive coronal displacement of the mucogingival boundary. Routine mucosa
transplantation to seal the alveolar access after the extraction is deliberately dispensed with, as this
would create additional costs and increased morbidity at the donor site. In the healing phase following
the extraction, the papillae and the facial contour of the alveolar ridge in the centre of the alveolus are
flattened, which is caused, as has already been shown, by the resorption of the bundle bone.
Basic surgical principles, as have been established for some time for aesthetic implant sites, should be
adhered to during the implant placement operation. (Buser and von Arx 2000; Buser et al. 2004). The
most important factor is a prosthetic-orientated implantation, for which reason the implant must be
inserted in the correct three-dimensional position. At the same time, the implant should be placed
with its implant shoulder, in the mesio-distal, corono-apical and oro-facial orientation, in the so-called
comfort zones. Early implantation following extraction, as a rule, results in a small to moderate bony
defect, which is generally 2-walled and must be augmented simultaneously at the time of implantation
in order to be able to achieve a long-term stable aesthetic result. The objective is a contour
augmentation with the build-up of a facial bony wall around 3 mm thick to support the facial soft
tissues. The long-term stability of the contour augmentation has been documented in a current
clinical study (Buser et al. 2013).
The surgical method for the early implantation has been described in detail, together with the biological considerations as to why this therapeutic
concept can be recommended for day-to-day use in clinical practice (Buser et al. 2008b).
Fig. 1 Clinical findings in the initial examination of
the 25-year-old female patient. The patient exhibits a high smile line and reports an accident several
years ago, which affected tooth 11.
Fig. 2 Tooth 11 exhibits a chronic infection with a
fistula in the peri-apical region.
Fig. 3 The dental X-ray shows the rooted tooth 11. It
was decided to extract the damaged tooth and to replace it with an implant.
Fig. 7 During the healing phase, as is usual, there is a
slight shortening of the papillae as well as a flattening in the centre of the alveolus on the facial side of
the alveolar ridge, which is caused by the resorption
of the bundle bone.
Fig. 8 The occlusal view shows that, within 4 – 8
weeks of soft tissue healing, no visible reduction can
be seen in the breadth of the ridge in the approximal
region of the tooth gap.
Fig. 9 The dental X-ray shows the residual defect in
the region of the former alveolus.
Fig. 10 The crater-shaped bony defect in the centre
of the former alveolus 11 can be easily seen after
folding the mucoperiostial flap outwards.
Fig. 11 The intra-operative occlusal view clearly
shows the excellent ridge breadth (> 6 mm) in the
region of the single-tooth gap.
Fig. 12 Following the insertion of the screw-retained
implant in a correct 3-dimensional position and the
application of a 1.5 mm healing cap, the exposed
implant surface can be easily seen in the region of
the crater-shaped defect. This is clearly within the
alveolar ridge.
Fig. 13 The occlusal view shows the correct orofacial position of the implant and the 2-walled bony
defect of the exposed implant surface. Reliable
bone regeneration using the GBR technique is of
benefit for this defect morphology.
Fig. 14 The exposed implant surface is covered with
locally harvested chips of autogenous bone in order
to promote bone re-formation in the region of the
defect as quickly as possible. The use of autogenous
bone chips facilitates a brief healing phase of around
8 weeks after implantation with simultaneous contour
augmentation.
Fig. 15 The bone volume is further optimised by local
augmentation using Geistlich Bio-Oss® granules.
The low substitution rate of Geistlich Bio‑Oss®
helps to maintain the volume of the alveolar ridge
over time, a factor of great importance to the
maintenance of the long-term aesthetic outcome.
Fig. 16 The occlusal view shows the contour augmentation using Geistlich Bio-Oss®. The underlying
bone chips are intended to promote the re-growth
of the new bone into the Geistlich Bio-Oss® layer,
which is important due to the low substitution rate
of the biological material.
Fig. 17 A collagen membrane, used as a barrier, is
applied in two layers in order to improve the stability. Geistlich Bio-Gide® not only acts as a temporary
barrier, but also as a place-holder and stabiliser for
the augmentation material applied.
Fig. 18 An important component of this concept is
the tension-free primary wound closure. For this,
it is necessary to make a relieving incision in the
periosteum in order to be able to move the flap
slightly coronally. The primary closure protects the
biological materials applied from the bacteria in the
oral cavity.
The 25-year-old Patient's Risk Profile
Aesthetic Risk Assessment
Low
Moderate
High
Medical status
Healthy
Smoking habits
Non-smoker
Light smoker
(≤ 10 cigarettes per day)
Heavy smoker
(> 10 cigarettes per day)
Patient's aesthetic expectations
Low
Moderate
High
Smile line
Low
Medium
High
Gingival biotype
Thick biotype, low-scalloped
Medium scalloped, medium thick
Thin biotype, high scalloped
Tooth crown shape
Rectangular
Alveolar infection status
Infection-free
Chronic infection
Acute infection
Bone level of the adjacent teeth
≤ 5 mm to contact point
5.5 to 6.5 mm to contact point
≥ 7 mm to contact point
Restoration status of the adjacent
teeth
Natural
Gap bre adth
Single tooth gap (> 7 mm)
Soft tissue anatomy
Intact soft tissue
Bone anatomy
Alveolar ridge with no
bony defect
Reduced immune system
Triangular
Restored
Single tooth gap (< 7 mm)
Multiple tooth gap
Soft tissue defect
Horizontal bony defect
Vertical bony defect
2. Treatment Objectives
Primary objective following the extraction:
> Soft-tissue healing over 4 – 8 weeks, in order to achieve an intact soft-tissue covering
Secondary objectives during and after the implantation:
> Implantation in the correct 3-dimensional position
> ocal contour augmentation in the facial region with autogenous bone chips, Geistlich Bio-Oss®
L
granules and Geistlich Bio-Gide®
> Primary wound closure with 6 – 8 week healing phase
> Aesthetic restoration with screw-retained implant crown
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Fig. 4 The dental extraction is performed without
creating a flap. The alveolus is curetted thoroughly
in order to remove the inflamed tissues.
Fig. 5 The extracted tooth shows signs of external
root resorption with a large amount of granulation
tissue.
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Fig. 6 A temporary partial prosthesis is provided immediately after the extraction in order to close the
gap aesthetically.
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