Clinical, microbiological, radiographical and heamatological evaluation of implant surface decontamination using air polishing in the non- surgical treatment of peri-implantitis; a randomized controlled study

Peri-implantitis is an infectious condition of the tissues around
osseointegrated implants resulting in loss of supporting bone and clinical
signs of inflammation (bleeding and/or suppuration on probing). Various
non-surgical and surgical treatment modalities have been described in the
literature including mechanical debridement and/or pharmaceutical therapy
(chlorhexidine, local or systemic antibiotics), aimed at removing bacteria and
decontamination of the implant surface. Despite these various treatment
strategies, the most effective treatment option for treating peri-implantitis
lesions in a non-surgical way remains unclear. Therefore the search for a
potentially beneficial treatment modality is still imperative. One such
potentially beneficial treatment might be the use of air polishing. Modern air
polishing devices and their specific powders for subgingival application are
becoming increasingly significant in the context of maintenance therapy. It has
been shown that supportive therapy consisting of debridement and
decontamination of implants and suprastructures with air polishing leads to
better clinical results than conventional mechanical supportive therapy. For
non-surigcal treatment of peri-implantitis, air polishing has only scarcely
been investigated. Studies that evaluated air polishing as non-surgical
treatment had small sample sizes and study designs varied among these studies.
If peri-implantitis is left untreated it may ultimately lead to implant loss.
Moreover, it is thought that peri-implantitis, like periodontitis, may extort
systemic effects. The inflammatory burden, consisting of bacteria and
inflammatory mediators entering the systemic circulation, is thought to be
related to the amount of inflamed peri-implant tissue. The greater the amount
of inflamed peri-implant tissue, the greater the amount (and the chance) of
bacteria and inflammatory mediators entering the systemic circulation may be.
On the basis of these considerations the aim of the present study is to
investigate the clinical, microbiological and radiographical effectiveness of
decontamination of the implant surface during non-surgical treatment of
peri-implantitis using air polishing. In addition, haematological samples will
be analyzed in order to evaluate the influence of peri-implantitis on systemic
inflammatory parameters (compared to standard values) and to evaluate the
effect of therapy on systemic inflammatory parameters.

The primary objective of this randomized controlled trial is to compare the
clinical effect of decontamination of the implant surface during the
non-surgical treatment of peri-implantitis using air polishing or ultrasonic
treatment. Secondary objectives are to assess the microbiological and
radiographical effects of these treatment options of peri-implantitis and to
evaluate the influence of peri-implantitis and its treatment on systemic
inflammatory parameters.

This protocol consists of a single-blind, randomized, controlled clinical
trial. A select group of fully edentulous patients (patients with upper and
lower full dentures) participating in the RCT will additionally be selected for
hematological evaluation.

All patients with peri-implantitis will be treated in a non-surgical way.
Patients will receive a full mouth periodontal and peri-implant treatment by a
professional oral hygienist in one or multiple sessions (depending on the
periodontal health status) Patients will be randomly assigned to a test or
control group. In the test group implants will be cleaned with the use of an
air abrasive device. In the control group implants will be cleaned with an
ultrasonic device (=care as usual). In both the test and control group, the
remaining dentition (teeth) will be cleaned using an ultrasonic device and hand
instrumentation. Immediately before subgingival debridement, all patients will
rinse their mouth with 0.12% chlorhexidine + 0.05% cetylpyridinium chloride
without alcohol (Perio-aid®) for 30 sec in order to reduce the intra oral
bacterial load. Clinical, microbiological and radiographical data will be
collected before treatment (T0) and 3 months after treatment (T3). Patients
with a successful treatment outcome at T3 (no bleeding/suppuration on probing
and pocket depth < 5 mm) will be re-evaluated at 12 months after treatment.
Patients with an unsuccessful outcome will continue with a surgical treatment
protocol (see concomitant METC proposal)
Additionally, in a subset of patients, samples for haematological evaluation
will be collected at baseline (before non-surgical treatment, T0) and at 3
months (T3) after the non-surgical treatment.

In addition to the regular visit (intake and 3, 6, 9 and 12 months follow-up)
all patients will have one additional appointment for research purposes only.
Other data will be collected during the regular follow-up visits (clinical
data, microbiological samples, digital intra oral pictures, x-rays). The
selected group of patients that will participate in the heamatological
evaluation will have another two additional appointments for research purposes
(before and after treatment (see flow chart page 13). This select group of
patients will have 8 instead of 6 appointments in total.