Condition category
Oral Health
Date applied
18/08/2008
Date assigned
20/08/2008
Last edited
24/01/2014
Prospective/Retrospective
Prospectively registered
Overall trial status
Ongoing
Recruitment status
Recruiting

Plain English Summary

Background and study aims
Traditionally dentists encourage the practice of recommending 6 monthly dental check-ups. There is, however, little information to either support or refute this practice, or to advise either patients or dentists of the best dental recall interval for the maintenance of oral health.
The purpose of this study is to investigate and compare the effect of three different arrangements for the timing of dental check-up recall intervals on oral health.

Who can participate?
Adults 18 years of age or older who have visited their dentist in the previous 2 years.

What does the study involve?
Participants will be randomly allocated to one of three groups:
Group 1: a fixed, 6 month recall interval.
Group 2: an individualised, recall interval based on the patient’s risk of dental disease.
Group 3: a fixed, 24 month recall interval.

What are the possible benefits and risks of participating?
The results of this study will provide much needed evidence on the best time interval between dental check-ups in order to improve and maintain oral health.

Where is the study run from?
The study is being organised by staff at the INTERVAL Dental Recalls Trial Office at the Dental Health Services & Research Unit, University of Dundee. Research groups from NHS Education for Scotland, the Universities of Aberdeen, Edinburgh, Glasgow, Manchester and St. Andrews are also involved. The study will be carried out in 44 dental practices across the UK (Scotland, England, Wales & Northern Ireland).

When is the study starting and how long is it expected to run for?
The study started in September 2011 and is expected to run until February 2017.

Who is funding the study?
National Institute for Health Research, UK.

Who is the main contact?
Prof Nigel Pitts
n.b.pitts@cpse.dundee.ac.uk

Trial website

Contact information

Type

Scientific

Primary contact

Prof Nigel Pitts

ORCID ID

Contact details

Dental Health Services Research Unit
The Mackenzie Building
Kirsty Semple Way
Dundee
DD2 4BF
United Kingdom
+44 (0)1382 420058
n.b.pitts@cpse.dundee.ac.uk

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

HTA 06/35/99

Study information

Scientific title

INTERVAL Dental Recalls Trial (Investigation of NICE Technologies for Enabling Risk-Variable-Adjusted-Length Dental Recalls Trial)

Acronym

INTERVAL

Study hypothesis

The principal research question is to investigate whether risk-based recall intervals or a fixed-period 24 month recall are more effective and cost effective in maintaining oral health than the traditional fixed-period 6 month recall.

Following successful delivery of a feasibility study from 01/08/2009 to 31/08/2011 and the award of new funding, the main trial is being undertaken during 01/09/2011 to 28/02/2017.

Ethics approval

Transition to the main trial was approved by Fife and Forth Valley REC on 23/09/2011 (ref: 09/S0501/1)

Study design

Multi-centre, parallel-group, randomised controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Other

Trial type

Other

Patient information sheet

Condition

Oral health

Intervention

In total, 2,288 participants will be recruited in order to retain 1,735 at 4 years.

This is a 4-year, multi-centre, parallel-group, randomised controlled comparison of three recall intervals: 6-month fixed-period recall, risk-based recall, and 24-month fixed-period recall.

Intervention group 1: 6-month, fixed period dental recall. Participants allocated to this group will attend their dentist at fixed, 6 monthly time intervals for a routine dental check-up. The content of this check-up will remain as per current practice. A recognised definition of a traditional NHS dental check-up is clinical examination, advice, charting including monitoring of periodontal status and report.

Intervention group 2: Risk-variable-adjusted-length recall interval. Participants allocated to the risk-based recall interval group will attend their dentist at time intervals determined by the evidence-based process outlined in the 2004 National Institute for Health and Clinical Excellence (NICE) guideline on Dental Recall. The recommended stages in establishing the appropriate recall interval are:
a. Establishing the age range
b. Consideration of risk variables
c. Integration and prediction of recall need
d. Discussion
e. Review

Intervention group 3: 24-month, fixed period dental recall. Participants deemed suitable by their dentist for allocation to this group will attend at fixed, 24 monthly time intervals for a routine dental check-up. The content of this check-up is as described for group 1.

Details of Joint Principal Investigator:
Dr Jan Clarkson
Dental Health Services Research Unit
The Mackenzie Building
Kirsty Semple Way
Dundee
DD2 4BF
United Kingdom
Tel: +44 (0)1382 420060
Email: j.e.clarkson@cpse.dundee.ac.uk

Intervention type

Other

Phase

Not Specified

Drug names

Primary outcome measures

Current primary outcome measures as of 29/09/2011:

1. Health related quality of life measured using an annual, self-administered patient questionnaire. Questionnaire will include a global assessment of quality of life using short form Oral Health Impact Profile, a standardised measure of health outcome (EQ-5D) and a specially developed, context-specific, health related quality of life measure.
2. Periodontal disease assessed by gingival inflammation/bleeding measured according to the Gingival Index of Loe.

All clinical outcomes are measured at 4 years by trained examiners who are blinded to allocation.

Previous primary outcome measures included both current outcome measures plus the following point:

2. Caries experience assessed at both the enamel and dentine thresholds using the validated International Caries Detection and Assessment System (ICDAS). The ICDAS criteria measure both early and more advanced stages of caries. For early caries, ICDAS measures the surface changes and potential histological depth of carious lesions by relying on surface characteristics related to the optical properties of sound and demineralised enamel prior to cavitation. All surfaces of all teeth will be examined and the status of each recorded in terms of caries and restorations. This system allows the recording of both preventive and operative care needs.

This has been moved to secondary outcome measures following discussion between funders, peer reviewers and principal investigators and is reflected in the approved main trial protocol

Secondary outcome measures

Current secondary outcome measures as of 27/09/2011:

1. Caries experience assessed at both the enamel and dentine thresholds using the validated International Caries Detection and Assessment System (ICDAS). The ICDAS criteria measure both early and more advanced stages of caries. For early caries, ICDAS measures the surface changes and potential histological depth of carious lesions by relying on surface characteristics related to the optical properties of sound and demineralised enamel prior to cavitation. All surfaces of all teeth will be examined and the status of each recorded in terms of caries and restorations. This system allows the recording of both preventive and operative care needs.
2. Plaque measured according to the Silness and Loe Plaque Index, calculus measured according to the Ramfjord Calculus Index and a colour-coded UNC periodontal probe will be used to measure periodontal pocket depth and clinical attachment level. The assessments will be made at 4 years by trained examiners who are blinded to allocation.
3. Patient-centred outcomes including dental anxiety, oral health related knowledge, attitudes, and behaviours, use of and reason for use of dental services (including symptoms and pain), and satisfaction with care measured using annual, self-administered questionnaire. Total duration of follow-up: 4 years.
4. Dentist attitude towards the different recall strategies measured using a self-administered questionnaire at month 0 and at 4 years

Previous secondary outcome measures included points 2 to 4 only.

Overall trial start date

01/09/2011

Overall trial end date

28/02/2017

Reason abandoned

Eligibility

Participant inclusion criteria

Adult patients 18 years of age or older who are dentate, have visited their dentist in the previous 2 years, and receive all or part of their dental care as an NHS patient.

Participant type

Patient

Age group

Adult

Gender

Both

Target number of participants

2,288

Participant exclusion criteria

Patients for whom periodontal probing is contraindicated or who have a medical condition indicating increased risk of bleeding (e.g., history of bacterial endocarditis, bleeding disorder, immuno-compromised).

Recruitment start date

01/09/2011

Recruitment end date

28/02/2017

Locations

Countries of recruitment

United Kingdom

Trial participating centre

Dental Health Services Research Unit
Dundee
DD2 4BF
United Kingdom

Sponsor information

Organisation

University of Dundee (UK)

Sponsor details

Research & Innovation Services
11 Perth Road
Dundee
DD1 4HN
United Kingdom

Sponsor type

University/education

Website

http://www.dundee.ac.uk

Funders

Funder type

Government

Funder name

NIHR Health Technology Assessment Programme - HTA (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes