Assessing the survival and fit of crowns provided for premolar and molar teeth which have undergone root canal treatment
| ISRCTN | ISRCTN69046497 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN69046497 |
| ClinicalTrials.gov (NCT) | Nil known |
| Clinical Trials Information System (CTIS) | Nil known |
| Integrated Research Application System (IRAS) | 325439 |
| Protocol serial number | UoL001789 |
| Sponsor | University of Liverpool |
| Funder | Investigator initiated and funded |
- Submission date
- 14/11/2024
- Registration date
- 27/11/2024
- Last edited
- 04/12/2025
- Recruitment status
- No longer recruiting
- Overall study status
- Ongoing
- Condition category
- Oral Health
Plain English summary of protocol
Background and study aims
This study aims to assess whether 3D printed hybrid resin-ceramic restorations perform as well as conventional milled ceramic restorations for teeth that have had root canal treatment. These restorations, such as crowns or onlays, are used to protect and restore the function of treated teeth.
Who can participate?
Patients who are 18 years or older and have had root canal treatment on their premolar or molar teeth can participate. The tooth must require a tooth-colored restoration and be restorable without needing a metal-based restoration.
What does the study involve?
Participants will be randomly assigned to receive either a 3D printed hybrid resin-ceramic restoration or a lithium disilicate restoration. The teeth will be prepared, and the restorations will be made and fitted by postgraduate endodontic students. The study will monitor the performance of these restorations over a year.
What are the possible benefits and risks of participating?
Participants will receive a free restoration for their root-treated tooth, which provides necessary protection. They will also benefit from a year of monitoring, allowing any issues to be addressed. There are no significant risks associated with participating in this study.
Where is the study run from?
The study is being conducted at the Endodontic Department of Liverpool University Dental Hospital (UK).
When is the study starting and how long is it expected to run for?
April 2023 to December 2026.
Who is funding the study?
Investigator initiated and funded
Who is the main contact?
Ahmed Elmatary, ahmede15@liverpool.ac.uk
Prof Fadi Jarad, f.jarad@liverpool.ac.uk
Contact information
Public, Scientific, Principal investigator
Liverpool University Dental Hospital
Liverpool
L3 5PS
United Kingdom
 ORCID ID |
0000-0002-5485-2706 |
|---|---|
| Phone | +44 151 706 2000 |
| f.jarad@liverpool.ac.uk |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Interventional randomised controlled trial |
| Secondary study design | Randomised controlled trial |
| Study type | Participant information sheet |
| Scientific title | Survival and clinical performance of indirect restorations provided for root canal treated teeth |
| Study acronym | CROWNS |
| Study objectives | The aim of the study is to assess whether 3-D printed hybrid resin-ceramic restorations have the same clinical performance and longevity as conventional milled ceramic restorations |
| Ethics approval(s) |
Approved 13/11/2023, North West - Greater Manchester South Research Ethics Committee (2 Redman Place, Liverpool, E20 1JQ, United Kingdom; +44 2071048065; gmsouth.rec@hra.nhs.uk), ref: 23/NW/0311 |
| Health condition(s) or problem(s) studied | Posterior root canal treated teeth requiring cuspal coverage restorations |
| Intervention | Patients are being randomised, via sealed envelope and a block randomisation method to either the 3-D printed group or the LiDi group. Teeth are then prepared to receive the cuspal coverage restoration and then randomisation occurs. The crowns/onlays are then received back from the lab and cemented if adequate. The treatment will consist of 3 appointments for each study participant: Appointment 1: Preparation of the Posterior Endodontically Treated Tooth for the Indirect Restoration (2-3 hours) Appointment 2 (2-4 weeks later): Fit of the indirect restoration and assessment of the fit using the Modified United States Public Health Service (USPHS) Criteria (45 mins-1 hour). Appointment 3: 1 year review appointment to assess survival of restoration and USPHS criteria used to score the restoration (30-45 mins). |
| Intervention type | Procedure/Surgery |
| Primary outcome measure(s) |
‘Survival/Non-Survival of the Restoration’ assessed chairside by 2 examiners at visit 3 (1 year review appt) |
| Key secondary outcome measure(s) |
1. Colour match is measured using USPHS criteria at baseline and 1 year |
| Completion date | 01/12/2026 |
Eligibility
| Participant type(s) | Patient, Service user |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 110 Years |
| Sex | All |
| Target sample size at registration | 80 |
| Total final enrolment | 82 |
| Key inclusion criteria | 1. 18+ year old patient requiring cuspal coverage of an indirect restoration 2. Root canal treated premolar/molar 3. Tooth requires tooth coloured restoration 4. Tooth is restorable 5. Tooth would not require metal-based restoration |
| Key exclusion criteria | Anterior (Incisor or Canine Tooth) |
| Date of first enrolment | 14/10/2024 |
| Date of final enrolment | 01/12/2025 |
Locations
Countries of recruitment
- United Kingdom
- England
Study participating centre
Prescot Street
Liverpool
L7 8XP
England
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan summary | Available on request |
| IPD sharing plan | The datasets generated during and/or analysed during the current study will be available upon request from Ahmed Elmatary, ahmede15@liverpool.ac.uk |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
Editorial Notes
04/12/2025: The total final enrolment was added.
15/11/2024: Trial's existence confirmed by North West - Greater Manchester South Research Ethics Committee.
