With this new system, dentists should be able to place implant-supported
restorations just weeks after placing the implants
by Dr. Bobby Birdi
The timing of implant restoration and restorative design have not changed tremendously
over the past 30 years with regard to immediate implant placement cases. We have seen the
advent of immediate implant placement—and even immediate provisional restorations—but
clinicians still wait 12–24 weeks before feeling comfortable placing a definitive restoration to
allow for predictable implant integration. This leads to patients having to wait months to get their
final implant-supported restorations.
How long a clinician waits to place a definitive restoration on a recently placed dental implant is
a multifactorial decision specific to each case. However, doctors have been taught that the healing
of a dental implant osteotomy involves a decrease in the initial stability of the dental implant
during the healing process. This is related to how an osteotomy has been prepared for decades,
involving the use of burs spinning at a high RPM, under copious irrigation, cutting the bone to
make the osteotomy—a process that has not changed much since the first screw-type dental
implant was placed by Dr. Per-Ingvar Brånemark in 1965.
As a result, the heat generation
and trauma involved in classically
preparing an osteotomy causes the
implant stability to “dip” during
Weeks 3–5 after the implant has
been placed. The implant stability
then increases to the final stability
level, achieving osseointegration at
Week 8 or more. As a result, most
clinicians elect to routinely wait
three or four months after implant
placement to load the implant with
a definitive restoration.
However, a new innovation
in osteotomy preparation, the
OsseoShaper instrument from
Nobel Biocare, prepares an
osteotomy at a very low RPM
and with no irrigation. This leads
to much less heat generation in
creating the osteotomy, which is
thought to decrease the prevalence
of an implant stability “dip” during
the healing process. Furthermore,
this tool leaves a vital bone
coagulum in the osteotomy, which
would be available to contact with
the implant at the time of implant
placement. As a result, clinicians
may be able to predictably place
definitive implant-supported
restorations just weeks after
surgical implant placement.
The case here showcases the
Nobel Biocare N1 system (Fig. 1),
which has a unique design and is
packaged with an OsseoShaper
instrument specific to each implant
to prepare the osteotomy in the
most atraumatic fashion to date.
Fig. 1
CASE REPORT
Initial presentation
and data collection
A 70-year-old patient presented with
a chief complaint of pain in her upper
right second premolar tooth. Upon
radiographic (PA and CBCT, Fig. 2)
and clinical evaluation of the tooth—
Grade 2 mobility and deep pocketing—
it was found to be cracked and
possessed a periapical radiolucency.
Overall, this tooth was deemed to
have a poor/hopeless prognosis and
needed to be removed (Figs. 3 and 4).
Adequate bone volume was evident
to predictably secure an immediate
implant in the extraction socket.
The patient was a long-standing
patient of the clinic and had received
many other successful implant-supported
restorations that had been
created using conventional osteotomy
preparation and loading times.
She was informed of the innovations
available with the N1 implant system
and was eager to have it used in her
treatment, because she loved the idea
of having her final crown placed in
a much shorter time than had been
involved with her other implants.
Atraumatic extraction and
innovative osteotomy preparation
On the surgical date, the area was
locally anesthetised and the tooth
was extracted atraumatically using
a flapless microsurgical approach
(Figs. 5 and 6). The implant osteotomy
was then initiated using an innovative
OsseoDirector instrument from Nobel
Biocare (Fig. 7), which allows for efficient
bone cutting in both apical and
horizontal directions as needed.
A directional indicator was then
placed and a periapical radiograph
taken to evaluate the trajectory of the
proposed implant placement (Figs. 8
and 9). Upon approval of the projected
trajectory, I opened a 4-by-11-mm
N1 implant package, which included
an OsseoShaper tool (Figs. 10 and 11)
to prepare the final custom osteotomy
to receive the implant.
Fig. 8
Fig .9
Fig. 10
Fig. 11
The tool is run at very low rpm
(40–60) with no irrigation. Like a
bone-tapping tool, it is run forward
until the osteotomy is prepared to the
desired depth; then, it is then reversed
out, leaving behind a vital bone coagulum.
By drilling just once with a bur
(OsseoDirector) conventionally and
then using the OsseoShaper instrument
to prepare the final osteotomy,
repeated drilling of the bone is
avoided, which helps avoid continuous
bone heating and trauma.
Implant and abutment placement
A xenograft (Creos Xenogain,
Nobel Biocare) mixed with high-concentration
PRP was placed into
the socket with a piece of leukocyte-platelet-rich fibrin. This was followed
by the implant, which has an ultrahydrophilic,
multizone anodized TiUltra
surface and a Tri-Oval crestal conical
connection, a shape that better mimics
the shape of a single-rooted tooth.
The N1 implant was placed 3 mm
apical and 2–3 mm palatal from
the proposed gingival zenith of the
desired restoration. Care was also
taken to place the implant with the
flat side of the Tri-Oval to the buccal
aspect of the socket (Fig. 12). An initial
stability of >35 Ncm was attained
from the implant placement, then
bone milling was completed using a
specific mill for this implant system.
This step removes any bone or tissue
above the implant connection that
would interfere with the seating of the
prosthetic components.
Studies have indicated that if we
can minimize the exposure of the
implant connection to the oral cavity,
the implant bone and tissue results
will be more predictable and have less
variation; thus, a “one abutment, one
time” concept has been conceptualized
to seal the implant/abutment
connection at the time of surgical
placement or Stage 2 uncovery.
Because of the customization and the
need for an implant-level impression
to create a final restoration with a custom
emergence profile, this concept
has been difficult to adopt with most
implant systems.
However, the N1 Base (Fig. 13) is
placed into the Tri-Oval connection
at the time of implant placement (or
Stage 2 uncovery) and is never taken
out again; the final implant restoration
is fabricated to screw into this base.
This allows for the implant/abutment
connection to be sealed off at the
time of initial exposure. In this case,
a 1.75-mm-tall N1 Base with a Xeal
anodized surface was placed into
the implant immediately after initial
implant placement, then was torqued
to specifications (20 Ncm). Then all
restorative work was completed to fit
onto the base. (Fig. 14)
Placement of immediate provisional
restoration and final impression
After the base was placed into the
implant and torqued to specifications,
a screw-retained provisional crown was
fabricated chairside using conventional
restorative materials and a provisional
abutment (Figs. 15 and 16). A closedtray
impression of the base was then
taken to create the future final restoration
(Fig. 17). The access hole for the
provisional crown was filled with PVS
impression material, and a final periapical
radiograph was taken (Fig. 18).
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Delivery of final screw-retained
crown, plus a one-year follow-up
At a postoperative appointment two
weeks after the implant placement
surgery, a single suture was removed
and the surgical site was evaluated.
Soft-tissue healing in the area was
exceptional for the two-week mark,
and the patient noted almost no
discomfort during the healing period
(Fig. 19). The provisional crown was
removed and the tissues were again
inspected; great health and healing
were evident (Fig. 20).
Fig. 19
Fig. 20
The N1 Base was again torqued to
specifications (20 NCm) to evaluate
stability of the implant, and no issues
were found. The final screw-retained
monolithic zirconia (ZirCad Prime,
Ivoclar Vivadent) was seated onto the
N1 Base and torqued to specifications
(20 Ncm). Occlusion, proximal contacts,
contours and aesthetics were all
evaluated. After all these factors were
approved by the patient, the access
hole of the final crown was filled with
Teflon tape and flowable composite
(Tetric EvoFlow, Ivoclar, Figs. 21 and
22). A final periapical radiograph
(Fig. 23) was then taken.
The stability and healing of the
implant site was monitored over the
next six months and then the patient
was seen at a one-year follow-up, at
which time another periapical radiograph
and photo were taken. Bone and
tissue levels were ideal, and the patient
was very happy with the overall result
(Figs. 24–26).
Conclusion
Implant site preparation has been a
stagnant field of implant dentistry for
many years. Conventional osteotomy
preparation continues to be used
throughout the industry. However, this
case demonstrates the benefits of an
innovative, minimally invasive way to
prepare an osteotomy that may lead
to increased reliability and decreased
variability in our results, and may
greatly decrease final loading times.
Dr. Bobby Birdi earned his dental degree
from the University of Saskatchewan
and postgraduate specialty training in
both periodontics and prosthodontics
from the University of Minnesota. He is
a fellow of the Royal College of Dentists
of Canada, and a diplomate of both the
American Board of Periodontology and
the American Board of Prosthodontics.
Birdi is one of the few board-certified
dual specialists in periodontics and
prosthodontics in North America, and
the first and only specialist in the world
to attain board certification in these two
specialties in both the U.S. and Canada.
He is the co-founder of the Digital
Dentistry Institute, a global learning
organization for dentists, and the founder
of the BC Perio Dental Health & Implant
Centres in Vancouver, one of the largest
and most technologically advanced
multispecialty dental centers in Canada.