Dentaltown August 2021 - 68

continuing
education
matrix, compared with the older protocol.
These white blood cells play an important
role in healing; they perform anti-infectious
action and regulate infl ammation by secreting
cytokines.7
Look into the details of your centrifuge
brand to fi nd the corresponding centrifugal
forces for each spin preset. Another great reference
for even more new platelet production
and utility innovations is Dr. Richard Miron's
new textbook Understanding Platelet-Rich
Fibrin, published in early 2021.8
Surgery
This patient's bony defect has the
advantage of neighboring root prominences
being large enough to support the volume
maintenance of the graft (Fig. 5a, p. 67).
The particulate bone will hold space in
the central area of the graft, and the root
contours will protect from lateral collapse
of the volume from the constant pressure of
the lips and cheeks (Fig. 5b, p. 67).
A full-thickness fl ap was laid that extended
from the mesial of #11 to the distal of #13.
Because there was minimal bone loss in the
interproximal areas and the probings were
normal, in my experience there is minimal
fear of causing iatrogenic recession; hence,
the fl ap could include the papilla. But there
is some debate on this issue, with evidence
for and against including the papilla.9
There are several clinical strategies
regarding the fl ap size. My typical approach
in a single-site onlay graft situation is to
extend just to the end of the neighboring
teeth on either side. (Some lecturers may
recommend longer extensions.) This particular
strategy works for me, and although the
sulcular extension of the fl ap is as previously
described, I release the tissue from the
bone 3-4 mm beyond these limits on both
sides with a periosteal elevator; in essence,
I " tunnel " past the visible limits of the
fl ap. This allows me to tuck the collagen
membrane into the pockets of the fl ap with
greater stability.
A scalpel can be used to gently score the
periosteum of the entire fl ap. This creates
greater fl exibility that will allow closure
over the added volume of bone without
tension. Tension creates constriction of the
Fig. 9a: CBCT cross-section before grafting.
Fig. 9b: After grafting and healing.
Fig. 9c: With digitally superimposed implant
and restoration before grafting.
Fig. 9a
Fig. 9b
blood supply and can lead to contraction,
dehiscence and tissue necrosis, ultimately
exposing and compromising the bone graft.10
Now that the fl ap is laid, the underlying
cortical bone can be cleaned of its remnant
periodontal ligament and connective tissue,
and small holes are made through the cortex
just into the medullary bone. This process,
decortication, creates a source of bleeding
from the more vascular internal layer of
bone (Fig. 6, p. 67). To grow bone, we need
a blood supply. Decortication helps create a
portal for bleeding and vascular formation
from the medullary space into the avascular
space of the bone particles.11, 12
Once good bleeding has been achieved
from the bone, the resorbable collagen
membrane can be tucked into the fl ap pocket
and the allograft placed into the defect (Fig. 7,
p. 67). The tunneling on either side allows
the natural pressure of the soft tissue and
the ceiling of the attached gingiva superiorly
to hold that collagen membrane in place.
This eliminates the need for tacks that some
clinicians use to secure membranes. A stable
membrane means a stable bone graft, which
Fig. 9c
Fig. 9d: With digitally superimposed implant
and restoration after grafting and healing.
Fig. 10a: Crestal fl ap laid when implant was
placed to assess viability of the new bone.
Fig. 10b: Implant placement.
Fig. 10c: Healing abutment placed and
fl ap secured with PGCL sutures.
Fig. 10d: Periapical X-ray showing
implant placement.
Fig. 10c
Fig. 10d
Fig. 9d
Fig. 10a
Fig. 10b
68 AUGUST 2021 // dentaltown.com
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Dentaltown August 2021

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