Title: INTERVAL Dental Recalls Trial [Investigation of NICE Technologies for Enabling Risk-Variable-Adjusted-Length Dental Recalls Trial] - Full Trial Follow-on
Funder: Chief Scientist Office, Scotland

Abstract: This parallel-group randomised controlled comparison of three forms of dental recall strategies ( 6 month recall, risk-based recall, and 24 month recall), will evaluate the effectiveness and cost effectiveness of these dental recall strategies by assessing their impact on maintaining oral health. Ethical concerns over the use of a 24-month recall interval expressed by some dental practitioners have been addressed by randomisation within two strata. The risk-based recall strategy is exactly that advocated by the recent NICE guidance - personalised variable intervals determined according to risk information derived from comprehensive oral health assessment and review. The two fixed-period recall strategies are the traditional six month intervals between routine check-ups or 24 month recall intervals between routine check-ups. The research will be carried out in general dental practices across the UK. Participating dentists will represent a cross-section of practitioners operating in a range of different circumstances (e.g. urban or rural settings, high, middle or low income communities, fluoridated (Birmingham, Newcastle-upon-Tyne) or non-fluoridated water (Scotland, Wales, Northern Ireland, NW England). Primary outcomes will be assessed in terms of specifically selected validated measures of quality of life using the 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. Periodontal disease will be assessed by gingival inflammation/bleeding measured according to the Gingival Index of Loe. All clinical outcomes operate at a sufficiently early stage of disease to assess the impacts of preventive care and health maintenance and are measured at four years by trained examiners who are blinded to allocation.

Lay abstract: 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 trial is to investigate and compare the effect of three different arrangements for the timing of dental check-up recall intervals on oral health. The first is a fixed, 6 month recall interval. The second is an individualised, recall interval based on the patient’s risk of dental disease. The third is a fixed, 24 month recall interval. The results of this trial will provide much needed evidence on the best time interval between dental check-ups in order to improve and maintain oral health. Because we do not know which check-up interval is the most effective for maintaining oral health, we need to make comparisons. People will be put into groups and then compared. The groups are selected by a computer which has no information about the individual (i.e. by chance). Patients in each group then have different check-up intervals and these are compared. The trial is being organised by staff at the INTERVAL Dental Recalls Trial Study 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 trial will be carried out in 44 dental practices across the UK. The study is funded by the Health Technology Assessment programme of the NHS (www.ncchta.org).

Research activity codes: 8.1 ORGANISATION AND DELIVERY OF SERVICES
Health categories: ORAL AND GASTROINTESTINAL