Dental Implant Therapy - Maintenance & Repair Procedures

Implant therapy is a treatment that has rapidly
become both state of the art and a standard of care.
There is, therefore, an increased need for proper
professional maintenance of these implants. As a
part of the annual dental examination it is essential
to assess the condition of implant fixtures and restorations,
and to provide the appropriate maintenance.
There are a variety of different types of implant
restorations. These include single or multiple tooth,
removable or fixed, and cemented or screw retained.
While procedures may differ slightly based
upon the type of restoration, several basic principles
can be applied regardless of the type of restoration.

Examination procedures
A general assessment of oral hygiene and soft
tissue health is similar to the requirements for natural
teeth. Accumulations of plaque or debris around
implant restorations should be noted and the patient
instructed in methods of proper oral hygiene. An
assessment of the character and presentation of the
periimplant soft tissues should be recorded, noting
areas that are red, inflamed, or bleeding. Tissues
should be well adapted to the implant restoration.
Gentle periodontal probing using a plastic probe
should be accomplished for evidence of disease. Of
particular concern are any areas that show evidence
of purulence.

Verify the stability of the restoration. Any mobility
noted is an indication of an emergent problem.
The most common cause of mobility is a
loose screw (see below). Verify that the restoration
is in implant-protected occlusion. Implant protected
occlusion is achieved when the occlusion on the
implant restoration provides only a very light drag
or resistance to shim-stock in maximum intercuspation
with a clenching force applied. There should
be no excursive contacts on the implant restoration.
Make any appropriate adjustments to the occlusion.

Radiographic evaluation
Annually, a radiographic assessment should be
made to monitor the crestal bone levels (1). Care
must be taken to ensure proper parallelism of the xray
beam is attained. The beam should be aligned
perpendicularly to the implant fixture. The threads
should be distinctly visible on the radiograph. A
comparison should be made with any previous radiographs.
Any area of radiolucency around the implant
fixture is an obvious area of concern. Initial
bone loss can be expected to be near the level of the
first thread. Additional bone loss of approximately
0.1 mm per year for the first five years (up to a total
of 1.5mm) is considered normal (2). Complete seating
of the associated parts (abutment and/or restoration)
should also be verified from the radiograph.

Maintenance procedures
If a dental prophylaxis is indicated, only plastic
instruments should be used to scale around implant
fixtures and restorations. Metal instruments, ultrasonic
scalers, or prophy jets must NOT be used to
clean implants. They may scratch or damage the
titanium fixtures and abutments. Polishing is performed
with a standard prophy angle, rubber cup,
and fine prophy paste.

Evaluate the restoration for overall integrity. For
the removable prosthesis utilizing a bar, ensure that
the attachment mechanisms are intact and retentive.
Any lost or broken retentive elements in the prosthesis
may either be processed as a conventional
prosthodontic repair, or referred to a command
prosthodontist. A soft reline material can be used as
an interim/provisional repair if a referral is deemed
necessary.

Bars may be removed and cleaned in an ultrasonic
cleaner. Clean and polish, but do not remove
the abutments. Check the abutments for tightness,
verifying proper torque (usually 20 Ncm.), prior to
replacement of the bar. Use new prosthetic retaining
screws when replacing the bar. Tighten the prosthetic
retaining screws (usually to 10 Ncm). If removal
of the bar is not indicated or desired, it can be
cleaned intraorally with a standard proph