Plain English Summary
Background and study aims
The use of single implant crowns to restore a missing tooth in the mouth has become standard procedure. With the aim to improve the esthetic (looks) outcome, an additional treatment phase referred to as “soft tissue conditioning” is carried out before the final crown is fabricated and placed on the implant. This phase involves the fabrication, placement, and modified in several steps, of a provisional single implant crown made out of composite, which can be easily modified. The rational to do this is to push and sculpt the soft tissue around the final implant crown, with a modifiable crown, until we reach a “soft tissue framework” that we are satisfied with, therefor guarantying and improved esthetic outcome than if we do not carry out this phase. The issue is that the esthetic benefit of this extra tedious phase is not proven in the available literature. There are very few randomized control clinical trials evaluating this issue. The evidence seems to point out that after 2 years, the initial benefit of having conditioned the tissues to an improved framework disappear. As the soft tissue around an implant crown will settle and improve to where it can improve, depending on the onsite anatomical characteristics, for example; bone level at the neighboring teeth, implant correct position, soft tissue thickness, crown design, etc. The aim of this study is to evaluate the esthetic results around single implant crowns, with and without a previous phase of soft tissue conditioning.
Who can participate?
Adults aged 22 and older require a tooth.
What does the study involve?
Participants with a single missing tooth and an implant already placed in the anterior region are randomly allocated to one of two groups. Those in the first group receive a provisional implant crown, which is modified a couple of times by adding composite or removing composite, to shape the soft tissue around the implant, with the aim to create the most beautiful sculpted soft tissue around the implant possible. This procedure is called soft tissue conditioning. It is widely recommended and used, in order to optimise aesthetic results, yet it is not proven in the available evidence that there is an aesthetic difference 2 years after crown placement, as the soft tissue may improve alone without the use of this conditioning phase. Those in the second group do not have a provisional crown and conditioning, but will receive the final crown immediately after second stage surgery.
Both groups will receive the same the type of final crown, the only difference is one will have a tissue conditioning phase, with 5 extra appointments (5 months extra in total), while the other group will have directly the final crown placed (with less efforts to achieve an aesthetic result). Both groups are followed up for three years, to evaluate if the aesthetic outcomes, and the biologic results differs between both groups.
What are the possible benefits and risks of participating?
Participants may benefit from having the cost of the treatment covered. They may also benefit from esthetic improvements. There are normal risks with the implant crowns procedure however the success rate for this procedure is high. There are no extra risks with participating in this study.
Where is the study run from?
1. Université de Genève (Switzerland)
2. Smart Dental Concepts (Germany)
When is the study starting and how long is it expected to run for?
September 2017 to November 2022
Who is funding the study?
Oral Reconstruction Foundation (Switzerland)
Who is the main contact?
Ms Cristina Zarauz
Trial website
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
ORF41703
Study information
Scientific title
Clinical, esthetic outcomes and efficiency of the one crown one time concept compared to the conventional approach encompassing soft tissue conditioning for the fabrication of single implant crowns: a pilot randomized controlled multicenter clinical trial
Acronym
Study hypothesis
1. No differences will be found between test group and control group with respect to the esthetic outcomes, biological and technical results.
2. Yet, a difference is expected in regards of treatment efficiency, i.e. less time, less efforts and less costs will be needed for the test group.
Ethics approval
Not provided at time of registration.
Study design
Randomised controlled clinical trial
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
Other
Trial type
Treatment
Patient information sheet
See additional files
Condition
Missing single tooth
Intervention
Participants with a single missing tooth and an implant already placed in the anterior region are randomly allocated to one of two groups:
Control group: Participants receive a provisional implant crown, which is modified a couple of times by adding composite or removing composite, to shape the soft tissue around the implant, with the aim to create the most beautiful sculpted soft tissue around the implant possible. This procedure is called soft tissue conditioning. It is widely recommended and used, in order to optimise aesthetic results, yet it is not proven in the available evidence that there is an aesthetic difference 2 years after crown placement, as the soft tissue may improve alone without the use of this conditioning phase. This is why we want to do this study, to test a conditioning group with a non- conditioning group (test group).
Test group: Participants do not have a provisional crown and conditioning, but will receive the final crown immediately after second stage surgery.
Both groups will receive the same the type of final crown, the only difference is one will have a tissue conditioning phase, with 5 extra appointments (5 months extra in total), while the other group will have directly the final crown placed (with less efforts to achieve an aesthetic result).
Both groups are followed up for three years, to evaluate if the aesthetic outcomes, and the biologic results differs between both groups.
Intervention type
Procedure/Surgery
Phase
Drug names
Primary outcome measure
1. Esthetic outcome is measured using the "PES/WES”: which is an esthetic index described by Belser in 2009 which is done by taking photographs (the photographs are examined and given points to different parameter, such as papilla fill, texture of soft tissue, volume, or color of soft tissue) at each follow up appointment
2. Volumetric changes is measured using digital models of the site of interest through the intraoral impression system
Secondary outcome measures
1. Biologic soft tissue outcomes is measured by registering the PPD (periodontal pocket depth), bleeding, and plaque around the implant crown at the follow up visit, which we would do anyway in routine control visits after crown placement
2. Biologic hard tissue outcomes is measured by registering the bone level changes: a small periapical radiograph is taken to evaluate bone level changes around the implant crown at the follow up visit
3. Efficiency comparison of the 2 protocols measured registering the time it takes in each procedure, and adding the time for all the procedures in the same protocol group. After, once the esthetic outcomes have been summed up, we may discus if the higher efforts of the control group was worth it.
Overall trial start date
30/09/2017
Overall trial end date
30/11/2022
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Older 22 years old
2. Patients with Conelog Implants placed in the anterior and premolar region in the maxilla or mandible.
3. These implants should:
3.1. Allow for a screw retained reconstruction
3.2. Be submerged (second stage surgery is the 1st study appointment)
4. Two neighboring teeth are present, or one tooth and one implant
5. Capable of providing written informed consent
6. Obtained informed consent from the patient
7. 2mm band of keratinized mucosa at implant site
8. Patients with adequate oral hygiene Plaque Index < 20% or persistent intraoral infection BoP < 20%
Participant type
Patient
Age group
Adult
Gender
Both
Target number of participants
32
Participant exclusion criteria
1. Medical condition that contraindicates surgery: ASA -score ≥ III
2. History of radiotherapy in the head and neck region
3. History of bisphosphonate medication
4. Women of childbearing potential with a positive urine pregnancy test
5. Medium smokers ≥ 10 cigarettes per day
6. Patients unwilling or incapable of understanding and signing the informed consent
7. Pronounced esthetic expectations
8. Severe bruxism or clenching habits
Recruitment start date
30/11/2017
Recruitment end date
30/06/2019
Locations
Countries of recruitment
Germany, Switzerland
Trial participating centre
Université de Genève
Division de Prothèse Fixe et Biomatériaux
Clinique universitaire de Médecine Dentaire
CUMD - 19, Rue Lombard
Genève
1205
Switzerland
Trial participating centre
Smart Dental Concepts
Dr. Happe und Kollegen Private dental practice
Schützenstr. 2
Münster
48143
Germany
Sponsor information
Organisation
Oral Reconstruction Fundation
Sponsor details
Margarethenstrasse 38
Basel
4053
Switzerland
+41 61 565 41 51
info@orfoundation.org
Sponsor type
Research organisation
Website
https://orfoundation.org/oral-reconstruction-foundationglobal-section/purpose-and-mission/
Funders
Funder type
Charity
Funder name
Oral Reconstruction Foundation (Switzerland)
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Results and Publications
Publication and dissemination plan
Planend publication in a high-impact peer reviewed journal.
IPD sharing statement:
The data sharing plans for the current study are unknown and will be made available at a later date.
Intention to publish date
30/11/2023
Participant level data
To be made available at a later date
Basic results (scientific)
Publication list