Dentaltown May 2021 - 46

Checklist and diagnostics
Upon initial examination, I like to go
through my basic checklist:
*	 Medical history/medications:
no contraindications.
*	 Oral health: multiple edentulous
areas, mild periodontal
inflammation (patient already
had scaling and root planning
performed), no pending
emergencies/infections, several
restorative needs.
*	 General occlusion: missing molars;
canine-to-canine occlusion suggests
Class I relationships.
*	 Anterior occlusion: mild wear,
1mm overjet, 2mm overbite.
*	 Biotype: medium thickness.
*	 Aesthetic demand: minimal.
*	 Goal: to remove the remaining root
and place an immediate implant.
This basic checklist is a preliminary one;
it is not meant to plan the entire case but
serves as a filter that tells me whether this is
going to be a relatively simple case (as this
is) or a more complex one that will require
some time set aside for further planning
(diagnostic models and wax-ups).
A cone beam image was taken to assess
several anatomical factors.
We can see from Figs. 2a-2c why this is
such a favorable case for a young implantologist
to foray into immediate implant placement:
Tooth #28 is almost centered in the alveolar
bone, with a thick lingual cortical plate and
a thinner but intact facial plate. This root,
as most lower premolars are, is a singular
conical root of average length.2
The angulation of the mandible in this
cross section appears very straight and vertical,
with a healthy appearance of trabecular
bone between the cortices. The very straight

Fig. 2a

46

Fig. 2b

nature of the bone means there are fewer
angles to accommodate when drilling the
osteotomy. The socket will provide a great
reference point for initial drilling angle in
the coronal plane from superior to inferior,
and the practitioner will mainly have to focus
on just the sagittal angulation from mesial
to distal. In other words, all you have to do
is drill straight down.
The inferior alveolar nerve was traced on
the viewing software and it exits the mental
foramen directly under Tooth #29 about
9mm inferior to its apex and 4mm distal
to the area below the planned #28 implant
site. This is a common spatial orientation of
the foramen, making the mandibular first
premolar a more technically safe implant
site than the second premolar.3
To recap key points:
*	 Ease of extraction: Conical roots
of lower premolars are most often
dislodged with simple elevation or
rotational forces using standard or
pediatric size 151 forceps.
*	 Safe distance from vital anatomy:
In the mandible, the inferior
alveolar nerve usually exits out of the
mental foramen closer to the second
premolar, not the first.
*	 90-degree vertical alveolus:
The fewer angles the clinician has
to accommodate in the surgery,
the less complicated it will be.

Beginning the surgery with PRF
For dentists using autologous platelet
products (Figs. 3a-3c), the best time to start
your blood draw is right after numbing.
There are a lot of different spin protocols
available these days, depending on the type
of final product you are looking for. It must
be remembered that the speed of the spin

Fig. 2c

is a factor of the design of your particular
centrifuge so we cannot be too attached to
one particular number when it comes to
RPMs; we should instead be more focused
in the amount of G-force generated by the
RPMs. This is dictated by the size of the rotor
assembly, the pitch of the tube holder, etc.
In general, for standard platelet-rich
fibrin (PRF) membrane, 200G's has become
the minimal relative force needed to create a
solid enough membrane without damaging
the platelets by over-spinning and to retain
more white blood cells, which will help
modulate the inflammation process in your
surgery site.4
Evidence has shown that adding platelet
products will make the allograft easier to
handle, because the plasma is viscous and
can be made to solidify, creating what is
known as " sticky bone. " Not only can this
make your surgery easier, but also it adds
almost 20 times the amount of platelets
that will release growth factors critical to
healing, compared with a natural blood clot.
The fibrin matrix helps keep these growth
factors in place longer, all assisting the healing
process, in particular vascularization.4,5
Chart 1 illustrates the flow chart for
surgery when incorporating platelet products.

Extraction
The extraction with lower premolars is
usually very simple. If there is enough tooth
structure above the bone, take a 15 blade
scalpel and gently do a sulcular incision to
separate any attachment in the sulcus to the
tooth structure. Then, using a standard or
smaller-size 151 forceps in rotational motions,
these very conical teeth will come out very
easily. I prefer a smaller or pediatric-size forceps
so that the beaks don't inadvertently pressure
or damage the neighboring teeth because
rotational movements may impede on the
space of the neighboring teeth. In this case,
however, the tooth structure on the lingual
is broken to the bone level (Figs. 4a and 4b),
not allowing for a point of purchase by the
forceps without removing bone.
Because this is the type of case where
there isn't much tooth to grab onto, and
compromised neighboring teeth, I recommend laying a conservative buccal flap and
removing interproximal bone on one side
using a surgical 557 bur, without extending

MAY 2021 // dentaltown.com

DT0521_Horton_Implants-MM.indd 46

4/19/21 10:30 AM
http://www.dentaltown.com
Dentaltown May 2021

Table of Contents for the Digital Edition of Dentaltown May 2021
