Dental Asia May/June 2022

CLINICAL FEATURE
Preventing
implant complications
By Dr Kevin Ng and Dr Zevon Ng
Implant complications arguably increase
the risk to patients. The term “success”
should be absent of any complications,
pathology or unpredicated which requires
chairside time to be treated or repaired.
Explaining to patients what is expected and
self-care are the most important factors.
Well treatment planning and regular reviews
every four to six months for maintenance
are the best ways to avoid complications. In
general, implants complications occur in the
following situations:
Fig. 1
DISCUSSION
A. Biological and technical complications
The most common reason for complications
to occur is insufficient implant treatment
planning which may lead to unnecessary
complications and positional failure. To
reduce complications, proper planning
requires a good understanding and
knowledge of anatomy, implant fixture or
prosthetic designs and the use of surgical
guides. Malposition of an implant can result
in long-term biological or mechanical
complications.
The aesthetic outcome of the crown relates
to the soft tissue profile, level, tone and
thickness. It is important to understand that
“the soft issue frames the restoration”.
Many authors have written on different
methods of increasing bulk by increasing
the volume of soft tissue. It is important
to manage at an early stage as part of
implant planning from start to finish.
Ensure atraumatic extraction and gentle
management of soft tissue during surgery.
Biomechanical failures: The most common
failures are the loosening of screws and
Fig. 3
breakage of implant components, which
can be avoided with proper planning
from the beginning. A thorough and good
understanding of the implant system and
screw joint mechanism and application
of proper torque as recommended by
the manufacturer. The failure rate in the
single-tooth restoration was reported as
10% 2 .
Today, with modern designs in connections
and components, we can avoid or minimise
failure by using a component that allows
us to reach high preloads and devices
that allow us to control torquing forces.
Implants made with internal connection
or are screw-free are less prone to screw
loosening and fracture.
Fig. 2
Another biomechanical failure could be due
to the fracture of the prosthesis caused by
metal fatigue. Porcelain fracture is common
and can be overcome by the choice of
zirconia material and a well-planned occlusal
scheme 2 .
Operators experiences: Failure rates were
twice higher for surgeons who had placed
50 or fewer implants compared with
surgeons who had placed 50-over implants.
Bone over-heating was the most common
problem during installations. However,
more experienced surgeons tend to be
overconfident to treat more complicated
cases which can be at an increased level of
implant failure.
Surgical trauma, contamination, medications:
The surgical preparation of the implant site
induces a zone of dead bone around the
fixture which affects the osseointegration to
take place. Micromovement of the implant
is related to the optimal fit between the
fixture and the drilled site. Adequate cooling
30 DENTAL ASIA MAY / JUNE 2022