Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT04534361 |
| Other study ID # |
SES-CEI-120820 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
August 15, 2020 |
| Est. completion date |
September 1, 2020 |
Study information
| Verified date |
November 2021 |
| Source |
Universitat Internacional de Catalunya |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
The scientific evidence available at present regarding the alterations suffered by the
alveolar ridge after the explantation of implants that have been considered to be abandoned
due to periimplantitis, as well as the remaining sequelae from said treatment, is scarce and
inconclusive.
Regarding this background, it is speculated that the different types of peri-implant defects
present different bone remodeling and different sequelae after the explantation of the
implants affected by peri-implantitis.
Thus, it has been hypothesized that the peri-implant defect configuration has an influence on
the radiographic bone alterations that occur after explantation.
In order to test this hypothesis, a retrospective study has been designed as it follows:
Patients who have undergone implant placement procedure and suffer from peri-implantitis will
be consecutively included in the study. In addition, patients should present at least 2 CBCTs
taken before and after explantation, 4-6 months apart. Linear measurements will be taken in
order to assess dimensional changes of the alveolar ridge at 1, 3, 5 and 7 mm from the bone
crest.
Description:
Peri-implant diseases have been a growing problem for the last decades. A recent
cross-sectional study conducted in the Spanish population has shown a prevalence of mucositis
and peri-implantitis at the implant level of 27% and 20%, and of 27% and 18% at the patient
level, respectively (Rodrigo et al. 2018). As the peri-implant disease progresses, it has
been observed that it generates different types of defects around implants affected by this
pathology. Recently, Monje et al. 2019, have classified these defects according to their
morphology (infrabony defects, supracrestal/horizontal defects or combined defects) and
according to the depth of the defect and total bone loss/total implant length (3-4mm/<25% of
implant length, 4-5mm/≥25-50% of implant length, >6mm/>50% of implant length (Monje et al.
2019).
Bone remodeling, as well as the sequelae or morphological alterations suffered by the
alveolar ridge after tooth extraction have been widely described in the literature (Amler et
al. 1960, Evian et al. 1982, Cardaropoli et al. 2003). In an animal model, Araujo and
coworkers described the alterations of the alveolar ridge following tooth extraction;
observing that bone height reduction of the buccal plate was more pronounced than the
lingual, and that vertical bone loss was always associated with horizontal bone loss (Araujo
et al. 2005). In contrast, the evidence available nowadays regarding the alterations suffered
by the alveolar ridge after the explantation of implants that have been considered to be
removed due to peri-implantitis, as well as the remaining sequelae from said treatment, is
scarce and inconclusive.
Therefore, the the primary objective of this study will be to evaluate radiographically the
influence of the peri-implant defect configuration on the radiographic bone alterations after
implant explanation.
In this sense, a retrospective observational study will be design. The protocol of which will
be approved by the Ethics Committee of the University of Extremadura (Badajoz, Spain), and
will follow the Declaration of Helsinki on human studies. In addition, this study will be
reported in accordance with the Analysis Strenghtening the Reporting of Observational Studies
in Epidemiology (STROBE) Statement .
Patient recruitment will be obtained from a private practice exclusively dedicated to
periodontics and implantology. Edentulous patients, either total or partial, who previously
underwent implant placement procedure will be consecutively included in the study. A
prerequisite for being eligible for the study was to have at least 2 CBCts, one taken before
explantation in order to diagnose peri-implantitis; and the other taken after explantation.
In order to define a peri-implantitis case, it will be based on the consensus report of
Workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-implant
Diseases and Conditions (Berglundh et al., 2018), in which it was stated that, in the absence
of baseline information, the diagnosis of peri-implantitis required: presence of bleeding
and/or suppuration on gentle probing, probing depth ≥6 mm and bone level ≥3mm apical to the
most coronal portion of the implant or at the rough-smooth interface in transmucosal
implants.
Once defined, several variables will be recorded, including both patient- and implant-related
ones. The former will include age, gender, type of edentulism (total/partial), history of
periodontal disease (mild, moderate or severe), tobacco smoking (heavy smoker >10
cigarettes/day; light smoker <10 cigarettes/day, former smoker 0 cigarette/day or
non-smoker), numbers of implant per patient, and keratinized mucosa (0, <2 or ≥2 mm).
Implant-related variables will include position (mandible / maxilla / anterior / posterior),
implant system (brand, diameter, length and type of connection), implant macrodesign
(transmucosal/bone level), type of prosthesis (single/multiple; screw/cement-retained), as
well as explantation method (trephine, tweezers, forceps or implant removal kit). In
addition, whether regeneration was performed or not after explantation will be recorded, as
well as the material used for it.
For the radiographic assessment, images were acquired by CBCT i-CAT Model 17-19 (Imaging
Sciences International LLC, Hatfield, PA, USA). The imaging parameters were set at a width
and depth of 16 × 13 mm, 120 kVp, 20.27 mAs, scan time 14.7 seconds, resolution 0.25 voxel
and a field of view (FOV), which varied based on the scanned region. Defect morphology and
severity were determined using the OnDemand3D software (Cybermed, Seoul, Korea) by one
previously calibrated examiner.
Prior to the assessment of the different radiographic variables, two reference lines will be
established: longitudinal axis of the implant and a perpendicular line to it tangent to a
reference point (sinus floor in the maxilla and mandibular base in the mandible). Several
parameters will be assessed before and after explantation in each implant, including:
bone-to-implant contact (BIC) at 4 sites (mesial, distal, buccal, lingual), defined as the
first contact between the bone and the implant surface, assessed from the most coronal part
of the intraosseous component of the implant; bone plate thickness (BPT), assessed at buccal
and lingual in mm. The reference point will be the bone crest and bone thickness will be
recorded at 1, 3, 5 and 7 mm from the crest. In addition, ridge width (RW) will be also
recorded at 1, 3, 5 and 7 mm from the bone crest. If there is any discrepancy between buccal
and lingual bone crest, the most apical one will be chosen as the reference.
In order to assess changes in bone crest height, the distance between the most coronal point
of the bone crest (buccal and lingual) and the reference line tangent to a fixed reference
point was calculated in mm.
BPT and RW at 1, 3, 5 and 7 mm will be also assessed when the implant has been already
explanted, recording the months that have passed from the explantation.
For the characterization of the peri-implantitis defects, the defect morphology and severity
classification by Monje and coworkers will be followed (Monje et al. 2019):
- Morphology:
- Class I: Infraosseous defect. Class Ia: Buccal dehiscence. Class Ib: 2-3 walls
defect. Class Ic: Circumferential defect.
- Class II: Supracrestal/horizontal defect.
- Class III: Combined defect. Class IIIa: Buccal dehiscence + horizontal bone loss.
Class IIIb: 2-3 walls defect + horizontal bone loss. Class IIIc: Circumferential
defect + horizontal bone loss.
- Severity: based upon the defect depth from the implant neck and ratio of bone loss/total
implant length
- Grade S: Slight: 3-4 mm/<25% of the implant length
- Grade M: Moderate 4-5 mm/ ≥25%-50% of the implant length
- Grade A: Advanced: >6 mm/>50% of the implant length
Regarding the statistical analysis, the statistical package (SPSS 15.0, SPSS Inc., Chicago,
IL, USA, STATISTICS, version 7.1StatSoft, Inc. will be used for this purpose. The Pearson
correlation test will be applied for the assessment of confounding factors and Linear
regression models based on generalized estimating equations (GEEs) will be used to analyze
the differences in the mean values of the post-extraction bone changes during the 2 time
phases. This model will consider the correlations of within-subject repeated measures.
