Seal or Varnish? A randomised controlled trial to determine the relative cost and effectiveness of pit and fissure sealant and fluoride varnish in preventing dental decay.

BACKGROUND: Fissure sealant (FS) and fluoride varnish (FV) have been shown to be effective in preventing dental caries when tested against a no-treatment control. However, the relative clinical effectiveness and cost-effectiveness of these interventions is unknown. OBJECTIVE: To compare the clinical effectiveness and cost-effectiveness of FS and FV in preventing dental caries in first permanent molars (FPMs) in 6- and 7-year-olds and to determine their acceptability. DESIGN: A randomised controlled allocation-blinded clinical trial with two parallel arms. SETTING: A targeted population programme using mobile dental clinics (MDCs) in schools located in areas of high social and economic deprivation in South Wales. PARTICIPANTS: In total, 1016 children were randomised, but one parent subsequently withdrew permission and so the analysis was based on 1015 children. The randomisation of participants was stratified by school and balanced for sex and primary dentition baseline caries levels using minimisation in a 1 : 1 ratio for treatments. A random component was added to the minimisation algorithm, such that it was not completely deterministic. Of the participants, 514 were randomised to receive FS and 502 were randomised to receive FV. INTERVENTIONS: Resin-based FS was applied to caries-free FPMs and maintained at 6-monthly intervals. FV was applied at baseline and at 6-month intervals over the course of 3 years. MAIN OUTCOME MEASURES: The proportion of children developing caries into dentine (decayed, missing, filled teeth in permanent dentition, i.e. D4-6MFT) on any one of up to four treated FPMs after 36 months. The assessors were blinded to treatment allocation; however, the presence or absence of FS at assessment would obviously indicate the probable treatment received. Economic measures established the costs and budget impact of FS and FV and the relative cost-effectiveness of these technologies. Qualitative interviews determined the acceptability of the interventions. RESULTS: At 36 months, 835 (82%) children remained in the trial: 417 in the FS arm and 418 in the FV arm. The proportion of children who developed caries into dentine on a least one FPM was lower in the FV arm (73; 17.5%) than in the FS arm (82, 19.6%) [odds ratio (OR) 0.84, 95% confidence interval (CI) 0.59 to 1.21; p = 0.35] but the difference was not statistically significant. The results were similar when the numbers of newly decayed teeth (OR 0.86, 95% CI 0.60 to 1.22) and tooth surfaces (OR 0.85, 95% CI 0.59 to 1.21) were examined. Trial fidelity was high: 95% of participants received five or six of the six scheduled treatments. Between 74% and 93% of sealants (upper and lower teeth) were intact at 36 months. The costs of the two technologies showed a small but statistically significant difference; the mean cost to the NHS (including intervention costs) per child was £500 for FS, compared with £432 for FV, a difference of £68.13 (95% CI £5.63 to £130.63; p = 0.033) in favour of FV. The budget impact analysis suggests that there is a cost saving of £68.13 (95% CI £5.63 to £130.63; p = 0.033) per child treated if using FV compared with the application of FS over this time period. An acceptability score completed by the children immediately after treatment and subsequent interviews demonstrated that both interventions were acceptable to the children. No adverse effects were reported. LIMITATIONS: There are no important limitations to this study. CONCLUSIONS: In a community oral health programme utilising MDCs and targeted at children with high caries risk, the twice-yearly application of FV resulted in caries prevention that is not significantly different from that obtained by applying and maintaining FSs after 36 months. FV proved less expensive. FUTURE WORK: The clinical effectiveness and cost-effectiveness of FS and FV following the cessation of active intervention merits investigation. TRIAL REGISTRATION: EudraCT number 2010-023476-23, Current Controlled Trials ISRCTN17029222 and UKCRN reference 9273. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 21. See the NIHR Journals Library website for further project information.

A comparison of a computer-based questionnaire and personal interviews in determining oral health-related behaviours.

BACKGROUND: A major challenge for survey-based research is to reduce bias. In an interview, subjects may claim more favourable behaviour to please the interviewer or comply with accepted norms. OBJECTIVES: This study aimed to: (i) determine if adolescents give different answers when using a self-completed computer-administered oral health questionnaire compared with a personal interview, (ii) ascertain if responses to a face-to-face interview are dependant on whether a dentist or nonclinical researcher administered the questionnaire and (iii) examine if responses were influenced by whether they undertook the computer questionnaire first or second. METHODS: A randomized crossover design was used to investigate the responses to 15 closed questions on oral health-related practices. These were administered to 453, 12-year olds attending school dental inspections in South Wales. RESULTS: A total of 449 valid pairings of computer/interview responses were available for analysis. Responses to the questionnaire variables demonstrated good to very good levels of agreement (kappa 0.68-0.90) when comparing the face-to-face and computer-administered questionnaire. With the exception of questions on dental attendance, responses were not influenced by whether the questions were posed by the research officer or the dentist. A minimal order effect could be detected when undertaking the computer-administered questionnaire first. CONCLUSIONS: Whilst a study such as this cannot determine the true validity of the responses achieved, it is concluded that a computer-administered questionnaire, comprising closed questions, can be utilized to determine oral health-related behaviours in oral health surveys.