A randomised controlled trial to measure the effects and costs of a dental caries prevention regime for young children attending primary care dental services: the Northern Ireland Caries Prevention In Practice (NIC-PIP) trial

Abstract

BackgroundDental caries is the most common disease of childhood. The NHS guidelines promote preventative care in dental practices, particularly for young children. However, the cost-effectiveness of this policy has not been established.ObjectiveTo measure the effects and costs of a composite fluoride intervention designed to prevent caries in young children attending dental services.DesignThe study was a two-arm, parallel-group, randomised controlled trial, with an allocation ratio of 1 : 1. Randomisation was by clinical trials unit, using randomised permuted blocks. Children/families were not blinded; however, outcome assessment was blinded to group assessment.SettingThe study took place in 22 NHS dental practices in Northern Ireland, UK.ParticipantsThe study participants were children aged 2–3 years, who were caries free at baseline.InterventionsThe intervention was composite in nature, comprising a varnish containing 22,600 parts per million (p.p.m.) fluoride, a toothbrush and a 50-ml tube of toothpaste containing 1450 p.p.m. fluoride; plus standardised, evidence-based prevention advice provided at 6-monthly intervals over 3 years. The control group received the prevention advice alone.Main outcome measuresThe primary outcome measure was conversion from caries-free to caries-active states. Secondary outcome measures were the number of decayed, missing or filled tooth surfaces in primary dentition (dmfs) in caries-active children, the number of episodes of pain, the number of extracted teeth and the costs of care. Adverse reactions (ARs) were recorded.ResultsA total of 1248 children (624 randomised to each group) were recruited and 1096 (549 in the intervention group and 547 in the control group) were included in the final analyses. A total of 87% of the intervention children and 85% of control children attended every 6-month visit (p = 0.77). In total, 187 (34%) children in the intervention group converted to caries active, compared with 213 (39%) in the control group [odds ratio (OR) 0.81, 95% confidence interval (CI) 0.64 to 1.04;p = 0.11]. The mean number of tooth surfaces affected by caries was 7.2 in the intervention group, compared with 9.6 in the control group (p = 0.007). There was no significant difference in the number of episodes of pain between groups (p = 0.81). However, 164 out of the total of 400 (41%) children who converted to caries active reported toothache, compared with 62 out of 696 (9%) caries-free children (OR 7.1 95% CI 5.1 to 9.9;p < 0.001). There was no statistically significant difference in the number of teeth extracted in caries-active children (p = 0.95). Ten children in the intervention group had ARs of a minor nature. The average direct dental care cost was £155.74 for the intervention group and £48.21 for the control group over 3 years (p < 0.05). The mean cost per carious surface avoided over the 3 years was estimated at £251.00.LimitationsThe usual limitations of a trial such as generalisability and understanding the underlying reasons for the outcomes apply. There is no mean willingness-to-pay threshold available to enable assessment of value for money.ConclusionsA statistically significant effect could not be demonstrated for the primary outcome. Once caries develop, pain is likely. There was a statistically significant difference in dmfs in caries-active children in favour of the intervention. Although adequately powered, the effect size of the intervention was small and of questionable clinical and economic benefit.Future workFuture work should assess the caries prevention effects of interventions to reduce sugar consumption at the population and individual levels. Interventions designed to arrest the disease once it is established need to be developed and tested in practice.Trial registrationCurrent Controlled Trials ISRCTN36180119 and EudraCT 2009-010725-39.FundingThis project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full inHealth Technology Assessment; Vol. 20, No. 71. See the NIHR Journals Library website for further project information.

Can government‐supported preventive fluoride varnish application service reduce pulp‐involved primary molars?

“…Tickle et al randomly allocated 1,248 children into two groups, one receiving composite fluoride intervention every 6 months and a control group. After 3 years, 19.3% of children from the fluoride intervention group reported toothache, which was not significantly different from the placebo group (21.9%) (12). The differences might have resulted from different measurements of "severe and extensive caries."…”

“…randomly allocated 1,248 children into two groups, one receiving composite fluoride intervention every 6 months and a control group. After 3 years, 19.3% of children from the fluoride intervention group reported toothache, which was not significantly different from the placebo group (21.9%) . The differences might have resulted from different measurements of “severe and extensive caries.” It is important to note that the Olivera and Tickle reports both described controlled clinical trials, whereas our data were obtained by retrospective review of the outcomes of a nationwide clinical practice implementation of FVAS.…”

“…recruited 1,248 children aged 2–3 years and randomly allocated them into composite fluoride intervention (FV, fluoride toothpaste, and prevention advice) and control groups (only prevention advice). After 3 years, they observed no significant differences between the two groups in the numbers of episodes of pain or number of teeth extracted . Because evidence on this issue is scant, the present study investigated the association between the government‐supported FVAS and the risk of undergoing treatments and early extraction of pulp‐involved primary molars, which is a surrogate for severe caries, by using a nationwide population‐based database.…”

Assessing the cost‐effectiveness of a fluoride varnish programme in Chile: The use of a decision analytic model in dentistry

“…To help make judgements decision‐makers could use a threshold value for the cost per caries‐free child. However, there is no evidence about how much Chilean (or any) society is willing to pay for a 6‐year‐old caries‐free child . Further studies, addressing this evidence gap are needed.…”

Implementation and trial evidence: a plea for fore-thought

“…Discusses a potential model that uses implementation as a fore-thought. undertaken in a dental context now conform to the design principles laid down by the Medical Research Council, [11][12][13] but there remain challenges implementing the evidence generated. These problems have led to a rapid growth in 'implementation science' , which is also known as 'knowledge translation' or 'knowledge mobilisation' .…”