PDF Download - Glidewell Dental Labs

Conventional implant planning typically involves the use
of a periapical radiograph (PA) and/or a panoramic film.
The drawback to these types of two-dimensional images is
distortion. The PA should be taken with a paralleling technique
to avoid vertical distortion as much as possible. A
radiographic marker of known diameter (e.g., 5 mm ball
bearing) can be used to determine the distortion in the
planned implant site. The marker is measured on the film
to determine the distortion factor in that area. A transparent
overlay can be used as an aid to determine the correct
implant selection (Fig. 1).
Another option is a CT scan. Cone beam scanners provide a
three-dimensional image and a precise method for identification
of the IAN. 8 The patient’s scan can be imported into
planning software, the mandibular canal identified, and the
implant placed in a virtual environment (Fig. 2).
In the case presented here, the canal was well differentiated
and identified. The mandibular canal is typically identifiable.
However, there are situations where the cortical bone
surrounding the canal is not dense and therefore does not
show up radiographically. These cases present a significant
challenge. One rule of thumb for first molars is to not drill
deeper than the roots of the adjacent teeth.
An optical scan of the model provides a clear view of
the anatomy of the teeth and the soft tissue (Fig. 3). The
appropriate-sized implant is placed within the confines of
the available bone (Fig. 4). It is important to be aware that the
drills are approximately 1 mm longer than the stated length
of the implant. The trajectory of the implant is aimed toward
the opposing stamp cusp through the center of the
occlusal table.
Figure 1: Implant radiographic template for Inclusive Tapered Implants
Figure 2: Digital Treatment Plan
Surgery
The osteotomy should be prepared with the aid of a
surgical or prosthetic guide. The prosthetic component of
the Inclusive ® Tooth Replacement Solution is a traditional
surgical stent designed to convey the ideal position of the
implant platform from the restorative perspective (Figs. 5, 6).
By starting the osteotomy using this guide, the implant will
be inserted in the appropriate location to take advantage of
the custom temporary abutment and BioTemps ® provisional
crown. The prosthetic guide is intended for prosthetic
reference only, and does not take into consideration any
anatomical landmarks or contraindications. This guide
should be used in combination with the radiographic and
clinical information to determine the best position for
the implant.
Figure 3: View of mandibular arch with proposed implant trajectory
A surgical guide based on the virtual plan utilizing a CBCT
scan of the patient provides the option of drill depth and
angulation control. Based on the amount of guidance
desired, a surgical guide can be produced that guides the
pilot drill. Subsequent drilling with progressively wider
20
– www.inclusivemagazine.com –