Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT02401789 |
| Other study ID # |
IIS-D 2013-017 |
| Secondary ID |
|
| Status |
Active, not recruiting |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
January 2015 |
| Est. completion date |
December 2023 |
Study information
| Verified date |
February 2023 |
| Source |
Institute Franci |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The objective of the present study is to evaluate if loss of multiple adjacent teeth will
cause proportionally greater tissue diminution than the loss of single teeth the possibility
of counteracting unfavourable ridge modeling after multiple tooth extractions by placing
implants in the fresh extraction sites soft tissue alterations at implants and adjacent teeth
Description:
The study will be designed as a prospective, randomized, controlled multicenter study
evaluating the potential of endosseous implants (OsseospeedTM,EV, Astra Tech System,
DentsplyTM, Mölndal, Sweden) placed in fresh extraction sockets to preserve the ridge
dimensions at the edentulous site.
Three centers will be involved in the study namely, (i) Department of Periodontology,
University of Padova, Italy, (ii) Institute Franci, Padova, Italy, (iii) Department of
Periodontology, Sahlgrenska Academy, University of Gothenburg, Sweden.
Prior to the start of the study the human review board at the treatment centers must approve
the study protocol as well as the informed consent forms.
Group assignment
Following the removal of the target teeth, the subject (site) will be randomly assigned to
one of 2 groups:
Test group 1:
Implants (OsseospeedTM,EV Astra Tech System, DentsplyTM, Mölndal) will be used. Preparation
of the osteotomy for the implant sites will include the use of drills. A guide drill will
establish the buccal-palatal/lingual and mesio-distal position of the implants. The final
osteotomy preparation will be done by a single pass of an appropriate drill. Using a
handpiece at 20 rpms and 50 Ncm of torque the implant will be placed. Primary stability must
be obtained. Furthermore, the operator must ensure that a blood clot properly fills the void
in the fresh extraction sockets. A MucograftTM membrane (Geistlich Pharma, Wolhusen,
Switzerland) will be adapted to the entrance of the hard tissue defects. Sutures will be
placed to secure the position of the membrane.The treatment should follow the guidelines
described in the Astra Tech Manuals 'Surgical Procedures' and 'Cement-or screw- retained
restorations -Clinical and laboratory procedures'. To avoid excessive loading of the implant
during the healing period, the patient is not allowed to use any implant supported temporary
restorations.
After 4 months of healing abutments will be installed (Healing AbutmentTM or Healing Abutment
ZebraTM). The soft tissue will be adapted and sutured back for a tight seal around the
abutment. The restorative procedure will commence and the prosthetic device inserted.
Control group:
No material will be placed in the socket. A MucograftTM membrane (Geistlich Pharma, Wolhusen,
Switzerland) will be adapted to the entrance of the hard tissue defects. Sutures will be
placed to secure the position of the membrane. After 4 months of healing implant installation
will take place (see above) and after another 3 months the prosthetic rehabilitation will be
performed.
Follow-up period During a 3 year follow-up period the subjects of the test and control groups
will be recalled every 6 months for professional tooth cleaning.
Procedures:
Stone models:
An impression of the target sites using a polyphosphate-based impression material will be
taken prior to tooth extraction and a stone model of the extraction site and adjacent teeth
will be produced.
New impressions and stone models will be produced one week following tooth extraction and
after 4 months of healing and after 1,2 and 3 years of follow-up.
Radiographs:
The supra-gingival portion of the teeth in (a duplicate of) the stone model (see above) to be
extracted will be carefully removed. The center of the future "extraction sites" will be
identified. A rigid acrylic splint - a guide including a quartz marker (Dual Scan MarkerTM (
Materialize Dental NV, Leuven, Belgium)- will be produced. This guide will be used for the
CBCT scans.
Immediately after a careful flapless extraction of the teeth, (i) a cone beam computerized
tomographic (CBCT) examination of the edentulous sites will be performed. The radiographic
examination will be performed with the Planmeca ProMax3D unit (Planmeca Oy, Helsinky,
Finland). The images will be acquired by means of the Planmeca Romexis software and processed
by a computer. Acquisition will be performed for 24s (volumetric dimension of 8 x 8 cm) with
the Planmeca tomography acquisition protocol: voxel size: 0.15 mm; Grey scale: 12 bits; focal
spot: 0.5x0,5 mm; image detector: amorphous silicon flat panel; image acquisition: single
270° rotation. The images will be generated in DICOM format and the files of each patient
will be saved and analyzed.
(ii) a series of standard intraoral radiographs, using the paralleling technique will be
obtained from each experimental socket and inter-dental bone.
A new set of CBCT scans will be obtained after 4 months of healing following tooth extraction
and after 3 year. New intraoral radiographs will be obtained prior to and after tooth
extraction, after 4 months of healing (before and after implant placement) and after 1, 2 and
3 years.
Recordings:
On the stone models (mm and mm2)
1. Maximum bucco-lingual width (mm) at midline of each extraction socket (see Schropp et
al. 2003)
2. The location of the crest -in relation to defined reference points at the adjacent
teeth- (i) next to adjacent teeth (mm) , (ii) at the center of each extraction socket
(mm and mm2 ) and (iii) at the position of the "inter-implant/tooth papillae"(mm) In the
CBCT scans measurements will be made at (i) the center of each extraction socket, (ii)
between the sockets ("inter-dental septum") (iii) at the septum next to adjacent teeth
Intraoral radiographs The changes in the crestal bone levels will be assessed and by
measuring the distance (MBL) from a defined reference point on the implant (adjacent
tooth surface) to the most coronal bone-to implant contact on the mesial and distal
aspect of the implant/tooth. In the radiographs the MBL distance will be recorded to the
nearest 0.1 mm using a magnifying (X7) lens.
Clinical examination This examinations will be performed at the visit of placement of the
permanent restoration and after 1,2, and 3 years and include the following; Soft tissue
inflammation: The condition of the mucosa/gingiva around all implants and adjacent teeth will
be assessed at 4 surfaces (mesial, distal, buccal, palatal) using a periodontal probe.
Inflammation in the soft tissue will be considered present when a site bleeds on gentle
probing (BoP).
Papilla fill: The degree of soft tissue fill in the inter-implant and tooth-implant sites
will be determined according to the criteria of the Papilla Index System (scores 0 - 4)
described by Jemt (1997).
Soft tissue margin: The distance between the margin of the permanent restoration and the most
apical level of the soft tissue margin will be measured at the buccal aspect of the implants
as well as a corresponding distance at neighboring teeth. This so called "mucosal zenith"
value will be measured with a periodontal probe and expressed in mm.
Statistical methods Clinical outcome variables: Main outcome variable will be the alteration
following tooth extraction of horizontal and vertical dimensions of the edentulous ridge
including both soft and hard tissues. Secondary outcome variables will be implant survival at
1, 2, 3 years, radiographic bone level and soft tissue change at implants/adjacent teeth and
extraction defects.
Power calculation based on the detection of a difference of 3 mm in mean crest width
difference between treatment groups, assuming a standard deviation of 3.0 mm (Schropp et al
2003), and with an alpha error defined to 0.05 and beta error to 0.20 (power 80%), revealed
that 17 subjects in each treatment group will be required. Considering a 10% drop out, a
total of 40 patients/teeth must be included.
For analysis of clinical efficacy, data from two slightly different analysis populations will
be used, i.e. the Per Protocol (PP) and the All Patients Treated (APT) populations. The
primary objective is to determine the alterations in the buccal and palatal aspects of the
size of the defect dimensions at implant placement and after healing. Results will be
presented by appropriate descriptive and inferential statistics. Continuous variables will be
presented by means of number of observations (N), minimum (min), median, maximum (max), mean
and standard deviation (std). Discrete variables will be presented by frequency and
percentage.
Experimental Schedule
Test group 1
Visit 1:
Soft tissue: all approximal surfaces (inflammation; PPD and Papilla Index) Impression: 2
stone models, preparation of Rx guide (stent) Rx: intra-oral radiograph(s)
Visit 2:
Extraction of target teeth, implant placement (non-submerged), wound closure, Mucograft
membrane. Impression: stone model Rx: CBCT Visit 3: 4 months Abutment connection Visit 4: 5
months Placement of definitive restoration Soft tissue: all approximal and buccal surfaces
(inflammation; PPD and Papilla Index) Rx: intra-oral radiographs and CBCT Visit 5: 1 year
Soft tissue: all approximal and buccal surfaces (inflammation; PPD and Papilla Index) Rx:
intra-oral radiographs and CBCT Visit 6 : 2 years Soft tissue: all approximal and buccal
surfaces (inflammation; PPD and Papilla Index) Rx: intra-oral radiographs Visit 7 : 3 years
Soft tissue: all approximal and buccal surfaces (inflammation; PPD and Papilla Index) Rx:
intra-oral radiographs and CBCT
control group
Visit 1:
Soft tissue: all approximal surfaces (inflammation; PPD and Papilla Index) Impression: stone
models, preparation of Rx guide (stent) Rx: intra-oral radiographs
Visit 2:
Extraction of target teeth, wound closure, Mucograft membrane Impression: stone model Rx:
intra-oral radiographs, and CBCT Visit 3: 4 months Impression: stone model Rx: intra-oral
radiographs, and CBCT Implant placement Visit 4: 7 months Abutment connection, Placement of
definitive restoration Visit 5: 8 months Soft tissue: all approximal and buccal surfaces
(inflammation; PPD and Papilla Index ) Rx: intra-oral radiographs and CBTC Visit 6, 7, 8 : 1
year, 2 years, 3 years
Soft tissue:
all approximal and buccal surfaces (inflammation; PPD and Papilla Index) Rx: intra-oral
radiographs At visit 8 In addition Rx: CBTC
