Condition category
Oral Health
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and Study aims
Root canal treatment is the procedure used to get rid of the bacteria present in the root canal system that cause inflammation or abscesses in the tissue around the end of the tooth where it fits into the jaw. The treatment involves drilling out of the canal space to allow thorough rinsing with a disinfecting solution to kill the bacteria. However, the best method of doing this is not known.
This study aims to identify the factors associated with good or poor tooth survival after root canal treatment by examining patient notes and X-rays from annual dentist visits. This will help dentists to choose the best ways of performing root canal treatment.

Who can participate?
1500 men or women aged over 16 years who are scheduled for root canal treatment or retreatment in the Department of Endodontics, Eastman Dental Hospital, UCLH.

What does the study involve?
Study participants will attend two appointments, with a 7-day interval, for routine root canal treatment or retreatment by one of the clinicians in the Endodontics Department. They will receive treatment as usual. The study will analyse information related to the pre-treatment condition of the tooth, details of the treatment, and condition of the tooth at each follow-up appointment from the patients' dental records.

What are the possible benefits and risks of participating?
Participants will receive treatment as usual. There is no direct benefit to the participating patients, but the information obtained may help improving the treatment of future patients suffering from the same condition. Participation in the study will not involve any disadvantages or additional risks.

Where is the study run from?
This study will take place at the Eastman Dental Hospital, UCLH, London, UK.

When is the study starting and how long is it expected to run for?
December 1995 to January 2023

Who is funding the study?
This study is self-funded. Clinical activities were carried out at the premises and under the sponsorship of Eastman Dental Hospital, UCLH.

Who is the main contact?
Professor Kishor Gulabivala

Trial website

Contact information



Primary contact

Dr Yuan-Ling Ng


Contact details

Unit of Endodontology
UCL Eastman Dental Institute
Gray's Inn Road
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A prospective evaluation of the individual and interactive influence of pre-operative, intra-operative and post-operative factors on the outcome of endodontic treatment procedures


Study hypothesis

To assess the survival probability and prognostic factors for periodontally involved teeth with advanced attachment loss managed by periodontal and root canal treatment, with or without root amputation

Ethics approval

Joint Research & Ethics Committee of UCL Hospitals NHS Trust, registered 06/12/1995, 96/E195. No formal ethics approval was required because the study only involved extraction of the data from clinical notes.

Study design

Observational longitudinal study

Primary study design


Secondary study design

Longitudinal study

Trial setting


Trial type


Patient information sheet

No participant information sheet available


Advanced periodontal disease


The participants attend routine root canal treatment appointments and subsequent routine annual follow-ups for 4 years post-operatively. They only consent for donation of routine clinical data for the study.

Intervention type



Drug names

Primary outcome measure

Tooth survival assessed using tooth extraction information provided by patients, referring dentists or notes in patients’ records. The duration of follow-up was annually up to 4 years post-treatment.

Secondary outcome measures

Periapical healing assessed using pain or swelling indicating periapical health based on clinical and radiographic examination. The duration of follow-up was annually up to 4 years post-treatment.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. With teeth that exhibited 5 mm or more clinical attachment loss or furcation involvement
2. With teeth that had undergone non-surgical periodontal debridement
3. Had undergone elective non-surgical root canal treatment prior to root amputation, or root canal treatment for management of concomitant pulpal or periapical pathosis followed by surgical periodontal debridement after being diagnosed as a “perio-endo” problem

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. With teeth with incomplete periodontal or root canal treatment data
2. With teeth with incomplete root canal treatment

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Eastman Dental Hospital, UCLH
256 Gray's Inn Road
United Kingdom

Sponsor information


Eastman Dental Institute, University College London

Sponsor details

256 Grays Inn Road
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type

Not defined

Funder name

self funded

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Planned 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


Participant level data

To be made available at a later date

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes